Latest / From First Principles / Astrobiology’s Biggest Survival Test + A Vaccine Against Everything? (EP. 29)
Transcript
- 0:00One of the biggest questions for humanity has always been, are we alone?
- 0:04And we may have just made a discovery that changes the paradigm about how we think about the answer to that question.
- 0:12So Sauron would be proud of this because Stanford has figured out one vaccine to rule them all.
- 0:19I don't really trust humans with nuclear weapons, but I definitely don't trust AI.
- 0:24And this new paper is corroborating that very nice viewpoint that I had.
- 0:30Hello, Internet.
- 0:31This is your captain speaking, Lester Nare, joined as always by my co-host and our resident Ph.D., Krishna Chowdhury.
- 0:40We are back for another week of science news.
- 0:43This week we have two phenomenal stories that we're going to touch on.
- 0:47First, we're going to hit an astrobiology story, followed up by an immunology story.
- 0:54And this week there's a little bit of a special surprise as our episode on the Dave Chang show, which will be on Netflix, is...
- 1:03We'll be dropping this week, so be sure to check that out.
- 1:05We got some phenomenal food.
- 1:06Yes, amazing food.
- 1:08From the goat.
- 1:09It was a great time.
- 1:10Shout out to Dave Chang and his team.
- 1:13Super big fan of science.
- 1:15A great example of how science impacts all of us.
- 1:18And curiosity, there is not a monopoly on curiosity about how the world around us works.
- 1:26If you're joining us for the first time, welcome.
- 1:29If you're returning, welcome back.
- 1:31As you know, we are a victim of the billionaire algorithm.
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- 1:55here to you every week.
- 1:58We are going to learn about the science from the ground up, because this is From First Principles.
- 2:21Our first story is on astrobiology, one of those fields that sits right at the edge of what science can currently say and addresses one of the biggest questions in humanity, which is, are we alone?
- 2:37And a new study just took one of the toughest organisms on Earth, simulated the violence of an asteroid slamming into Mars, and watched what happened.
- 2:47And the survival rates might genuinely surprise you as they surprised me.
- 2:52This is in PNAS Nexus out of John Hopkins University on March 3rd.
- 2:59Yeah, this is very recent.
- 3:00Fresh off the presses.
- 3:01Yeah, very recent.
- 3:02And as you said, right, a core question that we ask as humans is, are we alone?
- 3:07Well, a follow up to that would be, well, could life travel between worlds, right?
- 3:14Let's say that life started on Mars and then an asteroid impact hit it.
- 3:20The debris from that asteroid traveled the entire solar system between Mars and Earth and ended up on Earth.
- 3:26And that's what seeded life on Earth.
- 3:28This is the idea of lithopanspermia.
- 3:32Litho meaning rock, panspermia meaning this sort of like life everywhere type thing, right?
- 3:38And...
- 3:40For the longest time, it's kind of been just like cuckoo, woo-woo type science, been discredited.
- 3:46And this paper is really challenging a lot of the assumptions that we make about how unlikely this process is.
- 3:53The idea that life can generate in one place and then travel through the vacuum of space to another place and then continue to flourish.
- 4:01Yeah, yeah, dude.
- 4:03It's pretty cool.
- 4:04They've done some really cool experiments.
- 4:07This paper...
- 4:09uses something called D. radiodurans, which is a bacterium that colloquially is known as the Conan the bacterium because it's, like, indestructible.
- 4:19You know, like Conan the barbarian?
- 4:20I was going to say.
- 4:21It's, like, indestructible.
- 4:23And what they've done is do experiments about what this bacterium could survive through, and it turns out it's a lot.
- 4:30Something like 14,000 times the atmospheric pressure
- 4:34on earth okay um substantial survival even at really really high pressures even beyond that and the conclusion here is basically that the initial pressure shock that you get from an asteroid banging into a planet that has life and ejecting that planet out that initial pressure shock that we used to think would completely kill any living organism is actually not that bad
- 4:59Stuff will survive and go into outer space.
- 5:03Okay?
- 5:04Now, why does it matter?
- 5:05Well, very recently, we've had the NASA Perseverance rover announce a discovery of potential life on Mars.
- 5:13Yes.
- 5:14We covered this in last year's podcast.
- 5:16Okay.
- 5:17Now, finding that life requires determining the origin of that life, right?
- 5:22And if this is true, well, then we can start asking questions like, well, is that life coming from Earth or is it originated in Mars originally?
- 5:31This paper sort of shapes that interpretation.
- 5:34It's also got some impacts when it comes to like planetary protection, because now if we know that life actually survives impacts, goes into outer space and comes to Earth, like we got to be a bit careful about returning samples.
- 5:48onto Earth.
- 5:48Because if we bring something back and it's got a little thingy in it, we don't want that.
- 5:55Yeah, and there's plenty of science fiction movies about that, about how it can go really, really wrong.
- 6:00Hollywood has its ways of aggrandizing things, but it turns out it might actually be a real phenomenon.
- 6:07Very interesting.
- 6:09So, as always, let's start with the history.
- 6:11This is actually an ancient idea.
- 6:13The Greek philosopher Anna Zagor
- 6:16Anaxagoras, okay?
- 6:19Kind of like Pythagoras, but Anaxagoras.
- 6:22Maybe that's how you say it.
- 6:23Anaxagoras, 5th century BCE.
- 6:26Okay.
- 6:27He actually is one of the first guys to correctly interpret what the solar eclipse was, like the moon is going in front of the sun.
- 6:34He's the first guy to do that.
- 6:355th century BCE, so 2,500 years ago.
- 6:39He proposed the idea of spermata, which is seeds of life that are scattered throughout the universe.
- 6:45Now, the Greeks had a very rudimentary understanding of what...
- 6:49the universe was, but I still think it's quite cool that somebody that far ago was, you know, coming up with these kinds of ideas.
- 6:58The historical basis for the idea of panspermia really comes from William Thompson in the 1870s.
- 7:04This is Lord Kelvin.
- 7:06Lord Kelvin.
- 7:07Yes.
- 7:07He proposed the scattering of life seeds via, like, catastrophic collisions.
- 7:12This idea that we now have of, like, stuff going in.
- 7:15collisions, uproot material into space, and then that material comes into Earth.
- 7:21And then in 1903, there was this guy Svante Arrhenius.
- 7:24I think any chemist in the audience would know about the Arrhenius equation and all the great things that Svante Arrhenius did.
- 7:30But one of the things that he formalized was this idea of radiopanspermia, which is the idea that microbial spores, which are small enough, at that time they had figured out how small in mass these microbial spores were.
- 7:46they could be propelled by the pressure of light to move across space.
- 7:51And so that was his idea, radio panspermia.
- 7:53Now, in the 1900s, this idea was completely invalidated because in deep space we now know—we didn't know about radiation—
- 8:02back when Arrhenius came up with his thing.
- 8:04But now we know about cosmic rays and the solar wind and all the radiation and the dangers in space.
- 8:09So everyone was like, okay, unshielded deep space, you're going to have ultraviolet radiation.
- 8:14You're going to have this vacuum.
- 8:15It's rapidly going to sterilize DNA.
- 8:17So there's no hope.
- 8:19Right?
- 8:19Yes.
- 8:21Then we started discovering stuff that could actually survive that.
- 8:25In 1956, Arthur W. Anderson discovers D. radiodurans.
- 8:31This is our Conan the bacterium.
- 8:35I see.
- 8:35Okay?
- 8:36This is the bacterium that will survive anything.
- 8:39Okay.
- 8:39Okay.
- 8:39He was actually at the Oregon Agricultural College, and he was studying canned meat that he was trying to sterilize with gamma radiation.
- 8:48Gamma radiation is extremely short-wavelength radiation, extremely high-energy photons.
- 8:53And so that should just kill anything.
- 8:55It should break every chemical bond known.
- 8:58And the meat that he was studying spoiled anyway.
- 9:04And it didn't make any sense, right?
- 9:05It's like you put it into a freezer—
- 9:07Or like you put it into Chernobyl and the meat comes out still spoiled.
- 9:12So there's something that grew in it.
- 9:13And when he isolated that, he came up with this bacterium called D. radiodurans.
- 9:20In the 1970s, there was also the discovery of hydrothermal vents.
- 9:23And so now you have life thriving in total darkness, 400 degrees Celsius, like way above boiling.
- 9:31It's still water because the pressure is so high.
- 9:34But then again, the pressure is so high and life is still thriving.
- 9:38Yes.
- 9:38So it's very weird, right?
- 9:40And over the following decades, we've had an incredible catalog of extreme environments where life thrives.
- 9:47We have things called acetophiles, which are...
- 9:50Life that live in sulfuric acid.
- 9:52That's crazy.
- 9:53They literally live in sulfuric acid at a pH near zero, which is worse than bleach.
- 9:59But they're just like living there.
- 10:00Hyperthermophiles that live up to 122 degrees Celsius.
- 10:04The record holder is something called methanopyrus candelari.
- 10:09Kendall.
- 10:10Dude, 122 degrees Celsius is insane.
- 10:14Again, high pressure, which is why the water isn't boiling.
- 10:17Water usually boils at 100 degrees Celsius at sea level, but if you do it high pressure, the water's not going to boil.
- 10:22That's why a pressure cooker works.
- 10:24That makes sense.
- 10:26A lot of really, really crazy things.
- 10:28Halo files, they flourish in salt concentrations that are five times that of seawater.
- 10:33You can see this in the Dead Sea.
- 10:35You can also see this in Halo players who eat a lot of Doritos and chips and ruffles.
- 10:39Yes.
- 10:39Halo files, as those who might not know.
- 10:42I used to be a Halo-phile in high school.
- 10:44Mate, I loved Halo.
- 10:45Let me tell you something.
- 10:46Halo 2 and Halo 3.
- 10:48Oh, yeah.
- 10:49No competition.
- 10:49No competition.
- 10:51It was very serious.
- 10:52Oh, my gosh.
- 10:53It was very serious.
- 10:54It's one of the only games.
- 10:55Blood Gulch?
- 10:56Yeah.
- 10:56Like, what?
- 10:57Yeah, yeah, yeah.
- 10:59And I remember it was back in the day when, like, there wasn't really internet to host these collaborative parties.
- 11:07So you had to go to your friend's house.
- 11:09And I remember in the Valley, there was a friend's house that I used to go to.
- 11:14And he had a TV in one room and a TV in another room.
- 11:17And we used to do, like, co-ops of four versus four.
- 11:20Land parties.
- 11:21Land parties?
- 11:22Yeah.
- 11:22Yeah.
- 11:23Before Xbox Connect, before Xbox Live, we'll go back to the story.
- 11:26But this is our history.
- 11:29So we will give it the due respect.
- 11:32Halo raised so many millennials in that era.
- 11:36Yes.
- 11:36And we are one of them.
- 11:37Halo files.
- 11:39Yeah.
- 11:40In this case, it means salt.
- 11:41But for us, it means something totally different.
- 11:44So...
- 11:46Effectively, there's a lot of extreme environments that life thrives in.
- 11:50Right.
- 11:50So now it's no longer the case that life needs this perfect...
- 11:55setting the goldilocks yeah the goldilocks stuff right yeah and um one of the big things was in 1996 bill clinton announced possible ancient martian microbial life in a meteorite that they found in antarctica in 1984 i i have to ask because you did such a good job uh with the jfk impression if you could oh yeah so he goes he goes he goes i did not find life
- 12:24But I think we found it.
- 12:26But I did not have sexual related knowledge.
- 12:30Anyways, there was a meteorite in Antarctica.
- 12:33They found possible ancient life on it.
- 12:36It was published in Science.
- 12:38Immediately, everyone was like, no.
- 12:40Immediately, no.
- 12:41Immediately, no.
- 12:42Like, it was largely refuted.
- 12:45But the rock transfer, the fact that that meteorite came from Mars is actually not disputed.
- 12:52Meaning that the origin...
- 12:56On Google Maps, its original starting point is Mars.
- 12:59Is Mars.
- 12:59And that's not everyone's fine with.
- 13:01Okay.
- 13:01The fact that there's life on that meteorite, that's what everyone's not fine with.
- 13:05Okay.
- 13:05Okay.
- 13:05They saw little structures that kind of looked like bacteria and so on and so forth.
- 13:09They didn't have enough evidence.
- 13:11But it really started this question of could life survive the journey?
- 13:15Right.
- 13:15From Mars to Earth.
- 13:16Because now we have evidence that it can happen.
- 13:18That it can happen.
- 13:19We definitely found a Martian meter, right?
- 13:20And, you know, it looks like there's some weird stuff on there.
- 13:23And so that gets us to this mechanical challenge of planetary escape and then getting to Earth.
- 13:29Okay?
- 13:30So there's three bottlenecks when it comes to panspermia.
- 13:33Three things that prevent it from, like, being realistic or happening.
- 13:37Yeah, exactly.
- 13:38There's the first one is the impact ejection event, right?
- 13:42You get an initial shock.
- 13:44An asteroid impacts you.
- 13:46that's going to cause a bunch of pressure and
- 13:49over microseconds, and it's going to eject stuff into space.
- 13:54You've got to survive that impact.
- 13:57Okay.
- 13:57Once you survive the impact, then you've got to journey through space, millions of years in a vacuum.
- 14:02There's cosmic radiation.
- 14:04There's extreme cold.
- 14:05There's UV, right?
- 14:08And then at the end of the day, after you've done that journey, you've got to survive reentry.
- 14:13Okay?
- 14:15So you have to be big.
- 14:17And bulky to survive impact.
- 14:19You have to have endurance to last a long time.
- 14:22And maybe more also endurance and being big to survive reentry.
- 14:27Exactly.
- 14:28Right.
- 14:28So the two and three, which is surviving space and then surviving reentry, that's actually been...
- 14:35Explained by something called EXPOSE, which is a facility on the International Space Station.
- 14:41What they did was they had certain organisms and spores that they put out into the deep space right outside the International Space Station.
- 14:50And it turns out these things can survive prolonged space exposure if they're shielded by a few millimeters of rock.
- 14:59So if your life is just a few millimeters underneath the surface, yeah, underneath the surface of whatever asteroid, it's going to survive not only the vacuum of space, but also the reentry into Earth.
- 15:12That's actually quite, I think if people were to try to guess, if you have a piece of rock floating through space with little thingies, little microbe thingies on it, how deep do you think it needs to be to be able to survive?
- 15:27I think very few people would have guessed millimeters.
- 15:29Guess millimeters.
- 15:30You would think you need a little shielding.
- 15:31You need maybe a couple inches.
- 15:33Yeah, yeah.
- 15:33A couple feet, yards.
- 15:34Yeah, so you don't need a lot.
- 15:35That's actually really incredible.
- 15:36The interior of the rock actually heats minimally when you go into atmospheric entry.
- 15:41Oh, yeah.
- 15:42That's the idea.
- 15:42Okay.
- 15:43Right?
- 15:43And they actually found that this particular bacterium, D. radiodurans,
- 15:48it was already...
- 15:50It's like survived space-like conditions and it's the best at it.
- 15:53Okay?
- 15:54And so this particular paper that's coming out of Johns Hopkins, it is targeting bottleneck one, which is the idea of can it survive the initial ejection event?
- 16:05Because we already know it can survive outer space and re-entry.
- 16:08We need to know if it survives the ejection.
- 16:10So it can survive two and three of the three bottlenecks.
- 16:13We have...
- 16:16Data, experimental data, that shows that to be true.
- 16:20It's not theoretical.
- 16:21No.
- 16:22But number one is still...
- 16:23Number one is still, yeah.
- 16:25It's like if there's life on Mars and I hit it with an asteroid, by the time it gets out into outer space, most of it should be dead.
- 16:32That's the prevailing theory.
- 16:33Okay.
- 16:34This experiment is putting that...
- 16:37It's challenging it.
- 16:38Okay.
- 16:39Right?
- 16:40Science is always a process.
- 16:41Yeah.
- 16:42Sometimes things get put to rest.
- 16:43I mean, dude, it's a totally reasonable thing.
- 16:45Yes.
- 16:45To be like, hey, a meteor impact is like several atomic bombs.
- 16:49Yes.
- 16:49Okay.
- 16:50What are we talking about?
- 16:51100%.
- 16:51Right.
- 16:51100%.
- 16:53So, okay, let's talk about this elusive bacterium D radiodurans.
- 16:58Okay.
- 16:59Why is it the right test subject for this?
- 17:03Avenue of research.
- 17:04Okay?
- 17:05Well, for lethal dose for a human being, lethal dose being like, you know, 50% of us are going to die.
- 17:12It's about four grays.
- 17:14Gray is like the unit of radiation that you get.
- 17:17Chernobyl, Glenn.
- 17:18I just wanted you to know that, I don't know if you knew this, that grays are...
- 17:24One of the species of aliens that people think are visiting Earth.
- 17:28Oh, really?
- 17:29The four foot ones that have the big eyes.
- 17:32The classic.
- 17:33So only four of them will kill us.
- 17:36Okay.
- 17:39According to what we've done radiation studies on, four grays will kill us.
- 17:45E. coli takes 70 grays.
- 17:46Okay.
- 17:46Okay.
- 17:47Okay.
- 17:48D-Radiodurans takes 15,000.
- 17:49Yeah, that's cool.
- 17:51So it can survive 3,000 times the human exposure and 200 times the E. coli exposure.
- 17:58This thing is insane.
- 18:00That's why it's called Conan the...
- 18:02The barber.
- 18:03No, Conan the bacterium.
- 18:04The bacterium.
- 18:05The Conan the bacterium, yeah.
- 18:07So even those four-foot aliens, yeah, 3,000 times the dose of those four-foot aliens.
- 18:11Yeah, that's how they got here.
- 18:13That's how they got here, dude, on the backs of radiodurans.
- 18:16Yeah.
- 18:17Now, why is that the case?
- 18:19This bacteria is amazing.
- 18:21Okay.
- 18:22Okay.
- 18:23For one, in terms of DNA repair, it's got astonishing fidelity.
- 18:28Okay.
- 18:29It reassembles its genome, which can be shattered into hundreds of fragments by radiation within three to five hours.
- 18:37That's unbelievable.
- 18:38Like, I dose it with 5,000 grays, which is, again, 1,000 times what humans can take.
- 18:44Yeah.
- 18:45Within three to five hours, its genome is back.
- 18:47It's like this science fiction thing.
- 18:49It's unbelievable, especially after the episodes we talked about how our genomes, our DNA degrades over time.
- 18:55Yeah, naturally.
- 18:56This thing has repair mechanisms in order to just keep itself alive.
- 19:01The ring structure of the nucleoloid is a big part of it.
- 19:04The DNA is actually packed into a torus.
- 19:06It's like a donut-style shape.
- 19:08So it keeps the fragments physically close together.
- 19:11Versus a double helix.
- 19:13Yeah, exactly.
- 19:13Well, no, it's still a double helix.
- 19:15But it's rounded.
- 19:16But the double helix is wrapped around in a torus.
- 19:18Which gives it a little extra.
- 19:20Yeah, it's sort of not like in a soupy.
- 19:22Like most bacterium, the chromosome is in this soupy, non-structure...
- 19:30This one is in a nice toroid.
- 19:31Okay.
- 19:32So it's got physical proximity for easy reassembly.
- 19:36It also has multiple genome copies.
- 19:38Every single one of its cells has four to ten copies per cell.
- 19:42It's like that stuff we were talking about with GitHub.
- 19:44Yes.
- 19:45It's got several branches.
- 19:46Yes.
- 19:47So if one single branch of your GitHub is like messed up, it can use the others.
- 19:51to actually figure out how to repair itself, right?
- 19:54Exceptional DNA repair.
- 19:57One of the other cool things is it has extraordinary antioxidant defense.
- 20:01In 2004, there was a paper that came out in Science that suggested that, you know, over the course of radiation, you're going to have these things called reactive oxygen species.
- 20:10Oxygen is incredibly reactive.
- 20:12That's why things rust.
- 20:14Iron rusts in normal atmospheric conditions because the oxygen is reacting with the iron.
- 20:20Well, same thing happens in life.
- 20:21You have these reactive oxygen species.
- 20:23But these guys have so much high concentration of manganese antioxidants, which are like manganese ions, small peptides, that can scavenge and take care of that reactive oxygen.
- 20:35So it's keeping all of that reactive mechanism at bay.
- 20:38And finally, the cell envelope is really weird.
- 20:41The border of the cell to the outside, it's multilayered, and the outer layer is this S-layer crystalline surface layer.
- 20:49You can see it looks like a crystal.
- 20:51It's a hexagonal lattice where you've got this, like, fundamental unit, and it repeats itself.
- 20:58It's kind of like a shell around the bacterium that is keeping...
- 21:04That is like reinforcing that structure.
- 21:08It reminds me of when people talk about fractals.
- 21:11Yes.
- 21:11Like fractal patterns.
- 21:12It's like super structury, right?
- 21:15It almost looks like a virus, but it's the size of a bacteria, which is 100 times larger.
- 21:20You know?
- 21:21And it acts like a suit of armor providing this immense structural rigidity.
- 21:26Yeah.
- 21:27So there's the physical structure of this bacterium is such that it gets this extra layer of outer protection and has this genetic benefit of the structure of DNA such that external forces can't do a lot to it.
- 21:45Yeah, exactly.
- 21:46Like when radiation comes in and like messes up its DNA, it's got repair mechanisms that will just be like, oh, we got more.
- 21:53Yeah.
- 21:54Exactly.
- 21:54Yeah, it's like the robots.
- 21:56When we replace humans with robots, it's just like where you can manufacture them quickly.
- 22:01Yeah.
- 22:01And it's not unique, you know, and all the time it takes to have a human grow to be an adult and stuff like that.
- 22:07You can just be like, oh, robot out of the factory.
- 22:08It's already got it.
- 22:09Exactly.
- 22:10Yeah, dude.
- 22:10Conan the bacterium.
- 22:11Bacterium.
- 22:12This guy is crazy.
- 22:13Okay, so now let's look at can this thing survive an impact ejection?
- 22:17Right.
- 22:17Which is the idea of like a meteor comes in, slams into the earth.
- 22:22At insane energy, several atomic bombs.
- 22:26Can it survive this?
- 22:27So at sea level, we've got about 0.0001 gigapascals of pressure right now where we're at.
- 22:35Okay.
- 22:35Okay?
- 22:36The Marianas Trench is at 0.1, which is about 1,000 times more than at sea level.
- 22:40Can I ask a question?
- 22:41When you say pressure...
- 22:43How for our audience, like how would they experience what that means?
- 22:48Like, cause we do experience more pressure or like, how would you describe?
- 22:51Yeah.
- 22:51Pressure is, yeah, that's a good point.
- 22:53So pressure is force per unit area.
- 22:56That's how it's defined in physics, right?
- 22:58It's the amount of force that you're pushing on some amount of area.
- 23:01Now you can imagine if I'm pushing hand to hand, there's not a lot of pressure, but imagine now I have a pin.
- 23:10Right?
- 23:11Like the thumbtack.
- 23:12And now I push.
- 23:14Why does it go through my hand?
- 23:16Because there's a lot of pressure.
- 23:17The same amount of force is being concentrated on a tiny bit of area and that pressure is enough to pierce my skin and cause a lot of damage.
- 23:25That's a really good analogy.
- 23:27That's what I mean by pressure.
- 23:29It's like per...
- 23:30Per amount of area on your surface, how much is it pushing down?
- 23:34Okay?
- 23:35At sea level, it's not a lot.
- 23:37I mean, the amount of pressure that we have pushing in is the same as the amount of pressure we have pushing out from our blood and everything.
- 23:43And that's why we don't, like, get crushed.
- 23:46Unfortunately, do you remember the Titanic?
- 23:49Yeah, the submarine thing.
- 23:50The submarine thing?
- 23:51When you get down there, there's so much pressure, and the thing gave way.
- 23:55Everything collapsed, right?
- 23:57And then it just like completely killed everything.
- 23:59Yes.
- 23:59So that's pressure acting, right?
- 24:01Okay.
- 24:01Okay.
- 24:02And at the experimental low end for this particular paper, you've got 1.4 gigapascals.
- 24:08That's 14,000 times atmospheric pressure.
- 24:11Jesus.
- 24:11Jesus.
- 24:12And on the high end, you have three gigapascals, which is 30,000 atmospheric pressure.
- 24:17Now, why do we need to go that far?
- 24:22Okay, in terms of the amount of pressure is well outside what we as humans.
- 24:26What we as humans, right?
- 24:27Like, even on Mars, Mars is actually low pressure.
- 24:30It's way lower pressure atmospherically because Mars is smaller, so it doesn't have a big enough atmosphere, so the atmosphere isn't, like, actually pushing down.
- 24:37So why do we care about these high pressures, right?
- 24:40The reason we care about high pressure is to escape Mars, the rock has to reach an escape velocity, right, in order to get all the way to Earth or something like that, which is about 5 kilometers per second.
- 24:51On Earth, it's about 11 kilometers per second.
- 24:53But in any case, to get that fast...
- 24:57Direct acceleration means that you need like 50 gigapascals of pushing in order to get there.
- 25:03You're never going to survive that.
- 25:05On the other hand, in 1984, there was a theory called the shockwave spallation theory.
- 25:13This is the idea that a meteor is going to come in.
- 25:18And it's coming in so fast that the ground is going to act like a viscous fluid.
- 25:25Oh, wow.
- 25:26And that's actually what happens when meteors impact.
- 25:28They're coming in so fast with so much energy that the ground, the shockwave, is no longer a solid.
- 25:34It's like this viscous fluid.
- 25:36So the meteor comes in, and then the stuff around it bounces up.
- 25:41Because you've pummeled in.
- 25:43And so now the stuff around it is going up.
- 25:46There's this compression wave that...
- 25:49rebounds it rebounds from that impact and that rebound is going to projectile stuff out into the air to escape the gravity of the body and that's how we get yeah and that's how we get that escaping right okay and to get that escaping that is about a five gigapascal to one gigapascal shock now that's lower than the 50 gigapascals that we thought
- 26:14What's going on, right?
- 26:16So the idea is the meteor comes in, hits it.
- 26:19There's stuff around.
- 26:20And that stuff that's around is going to get shot back up as a rebound.
- 26:25And that rebound might be enough.
- 26:28It's still 30,000 times the atmosphere of the Earth.
- 26:32But it's still, it might be enough that these things survive.
- 26:35The other clue as to why it would survive is because it's not really sustained pressure.
- 26:40This is transient.
- 26:41This happens over like a microsecond.
- 26:43This thing impacts.
- 26:45This thing goes in.
- 26:46The pressure that this thing...
- 26:48that the ground fields is over a microsecond, right?
- 26:52It's extremely short.
- 26:53So maybe that brief shock will leave the cells mechanically intact.
- 26:59That's the question that they're trying to answer.
- 27:01Okay.
- 27:01This, this, this makes sense.
- 27:02Okay.
- 27:02So just to briefly summarize, because the idea is when we are trying to ascertain if panspermia is a thing, which means life arises on one rock ground,
- 27:16and then moves to another rock that's orbiting around a star.
- 27:21The life on rock number one needs to be able to have enough to escape the atmosphere.
- 27:28Yeah.
- 27:28We have rockets, but in lieu of rockets, you have some object come disrupt the ground with enough force such that it shoots stuff away.
- 27:38out of the gravitational pull of the rock that you're on.
- 27:41Yeah.
- 27:41And so now you're in space and you're traveling around.
- 27:44And so there are all these stages of that entire process for how does an organism, uh,
- 27:50yet from one place to another when it's not on a rocket.
- 27:54Yes, exactly.
- 27:55And this is the theory, right?
- 27:57Okay.
- 27:57The thing comes in, there's a rebound, and then it gets flung out into space.
- 28:01Yes.
- 28:01And so now we get to the actual paper, right?
- 28:05The actual paper, and if we go to photo 14, is...
- 28:11A paper in PNAS, which is the Proceedings of the National Academy of Sciences.
- 28:15Not that other word you weirdos were thinking about.
- 28:17No, no.
- 28:18This is PNAS.
- 28:19Everyone knows about PNAS on Science.
- 28:21Guys, come on.
- 28:23It's about extremophile survives the transient pressures associated with impact-induced ejection from Mars.
- 28:31That's exactly what they're doing.
- 28:32That's exactly what they're doing.
- 28:33They're making the case that this particular...
- 28:37bacterium, D-radiodurans, can survive that insane pressure all the way up to 3 gigapascals, right?
- 28:46I mean, that's a big thing because that totally changes the calculation.
- 28:49When we talk about things like the Fermi paradox, where is everybody?
- 28:51Yeah, and we're going to get to that.
- 28:53We're going to get to that.
- 28:54So let's pause on that.
- 28:55And let's talk about how they actually did the experiment because this is from first principles.
- 29:00We're going to talk about how they did the experiment.
- 29:02First, you need to biologically sample PrEP.
- 29:04Right.
- 29:05So here's what they did.
- 29:06They had the radioduran cells, the bacterial cells.
- 29:11Yes.
- 29:12In this like circular plate.
- 29:14And they sandwiched those cells.
- 29:16This is about a billion cells that they put inside like a Petri dish.
- 29:20But it's like a circular Petri dish.
- 29:21They sandwiched those cells between two large steel plates.
- 29:27Mm hmm.
- 29:28And then they seal it.
- 29:30It almost looks like a Canon camera lens.
- 29:32Yeah, totally.
- 29:33Where in the center, you have your biological sample.
- 29:36And then you're sort of like collapsing a bunch of steel plates on top, right?
- 29:40Now, what we're going to do with that plate is we are going to hit it.
- 29:44With a gas gun.
- 29:46Okay.
- 29:46Okay?
- 29:47The gas gun looks like the following.
- 29:49You've got the projectile, which is your flyer plate.
- 29:53Yes.
- 29:54That's another piece of steel.
- 29:55Okay.
- 29:56And that piece of steel is going to be propelled by gas.
- 29:59It's the same kind of like in car mechanic shops where you have the gas hydraulics.
- 30:05Oh, yes.
- 30:05Yes.
- 30:06It's...
- 30:06I mean, it's obviously more sophisticated than, like, the car.
- 30:09But it's the same thing, right?
- 30:10It's like a gas gun that is, like, propelling a flyer plate to impact the plate that has your bacteria.
- 30:17Yes, yes, yes.
- 30:18And then when you impact that bacteria, that is going to create the microsecond strain that mimics...
- 30:26The asteroid impact on Mars.
- 30:29So the idea is that in this graphic we see on the left, there is this projectile.
- 30:35There's a wedge and a fireplace.
- 30:36So that is what is shooting out.
- 30:38Yeah.
- 30:38With a gas.
- 30:39Like, it's high-pressure gas that shoots out, and it shoots into a circular plate.
- 30:45If you go to the gas station or car wash, when you pump your tires and you click the thing, it shoots the air out.
- 30:51Yeah.
- 30:52Yeah.
- 30:52Just conceptually.
- 30:53Yeah, that's exactly this.
- 30:54It's shooting at levels that are not pumping your tires.
- 30:58Yeah, yeah, yeah.
- 30:59This is much higher pressure.
- 31:01And the advantage here is that...
- 31:03So I'm shooting my...
- 31:05gas plate and interacting with this plate that has my sample, right?
- 31:10Yes.
- 31:10I can polish the other side.
- 31:13Okay.
- 31:13The backside.
- 31:14The backside.
- 31:15Okay.
- 31:15Such that it's a mirror.
- 31:16Okay.
- 31:17And then I can shoot lasers at it.
- 31:18Oh, my God.
- 31:19And then I can really hone in on what the dynamics of the trajectory is, like how much pressure was there, how much strain was there in each direction, because I can monitor how the laser is coming out.
- 31:30Because, and just to reiterate, the laser is the means by which you can measure stuff.
- 31:36Yes, exactly.
- 31:37It's a measurement instrument.
- 31:38Yeah, and the measurement instrument, because we're so good at lasers.
- 31:41Yes.
- 31:41Right?
- 31:41And measuring, like, frequency and all this other kind of stuff.
- 31:44We can measure exactly the amount of pressure that was imparted in that microsecond.
- 31:50Yes.
- 31:50Right?
- 31:51That's what's hard to measure.
- 31:53But these guys have leveraged all of the optics that physics is very good at.
- 31:57That's so clever.
- 31:58It's so clever.
- 31:59I really like that, actually.
- 32:00Because at first blush, frankly, their initial reaction is like, oh, that doesn't sound like what would happen on the surface of Mars.
- 32:09No.
- 32:10However.
- 32:10But they're recreating exactly the Pascals, like the amount of pressure.
- 32:14Exactly.
- 32:15The amount of transients, right?
- 32:17Because it only has to happen over a microsecond.
- 32:19Yes.
- 32:19So this contact has to happen very quickly.
- 32:21It's got to be a shot, you know?
- 32:23Yes, that's quite nice.
- 32:24Yes.
- 32:24It's quite nice.
- 32:25That's quite nice.
- 32:25And so now let's see what they're actually doing.
- 32:28Okay.
- 32:29What are the findings that they actually get?
- 32:31How they measure is the number of colony-forming units.
- 32:34Okay.
- 32:34And this is something that we used to do in microbiology lab as well, is you basically, like, swab and put it into a Petri dish with, like, agar, which is, like...
- 32:44solution that grows bacteria and then if there's a single bacteria that survived that's going to create a colony because it's going to replicate over some time and you can count the number of colony forming units and that'll give you a proxy for how many survived because you knew the initial concentration of how many bacteria you put in into that like yes apparatus right yes and now let's
- 33:10It's insane.
- 33:11All the way up, all the way up to 2.4 gigapascals, you had 60% survival.
- 33:172.4 is 24,000 times that on Earth.
- 33:22Yes.
- 33:22Right?
- 33:23The survival falls below detection limit only when pressures exceed 3 gigapascals.
- 33:29Jesus.
- 33:29And one of the cool things was Lily Zhao, who's one of the senior authors on the paper, she noted that the hardened steel experimental containers began to structurally fail before the bacteria actually got eradicated.
- 33:44So the point is our own engineering was not even sufficient enough to get to levels where the bacteria were chilling.
- 33:54At least 20% were still alive, but we couldn't test farther because we were testing pressures where the steel was like, I don't know what you want from me.
- 34:03We don't have the material science for it.
- 34:04Yeah, exactly.
- 34:05That's fascinating.
- 34:06It's fascinating, right?
- 34:07And if you look at standard microbes, E. coli plummets to 10 to the minus 3 to 10 to the minus 6 survival rates below 2 gigapascals.
- 34:18Our radiodurans, Conan the bacterium, achieved very high rates.
- 34:23So Conan the bacterium is the green dots on the very top.
- 34:26All of the other stupid bacteria are surviving way lower.
- 34:31And this is on a log scale on the y-axis.
- 34:33And so just to be clear, we're looking at a graph here that has pressure...
- 34:38On the x-axis.
- 34:38And the x-axis is gigapascals.
- 34:40And then survival rate on a log scale on the y-axis.
- 34:45Yeah.
- 34:45And there's all the other stuff that's like in the middle.
- 34:48Yeah, it's like E. coli.
- 34:51But at the top, across the board, at multiple different pressure types, it's very consistent.
- 34:57Yeah.
- 34:57Okay.
- 34:58So Conan is sick.
- 34:59He's surviving everything.
- 35:02He's surviving everything.
- 35:03Okay.
- 35:03Okay.
- 35:04Um, this is where it gets really, really cool.
- 35:07Okay.
- 35:08Cause so far, okay.
- 35:08We've, we've shown that this radio Duran survives.
- 35:12Right.
- 35:13Again, coming back to the original point here is we're starting off with this idea of is PAMSpermia a thing, which is life going from one rock through the vacuum of space to another rock.
- 35:25And part of the current paradigm was that in order for an organism not powered by rockets or some advanced technology would require an impact on that planetary body.
- 35:42of a level of force such that it would eject it into the vacuum of space.
- 35:50Yeah.
- 35:50And initially the idea was, oh, no way.
- 35:53The level of force necessary to eject you out there, you're dead.
- 35:56It's just going to kill you.
- 35:57You're just dead.
- 35:57Yeah.
- 35:58That's the current paradigm that the paper has now experimentally shown on Earth.
- 36:04Yeah.
- 36:05We have organisms that would survive this theoretical impact.
- 36:09Yes, exactly.
- 36:10So we have shown that it would survive this theoretical impact.
- 36:13Now let's look at what actually happens to them.
- 36:15Okay.
- 36:16If you look at transmission electron microscope images of these bacteria, you can actually see that at higher pressure, the cell walls get ruptured.
- 36:29Yes.
- 36:29Okay?
- 36:30So that's why the survival is going down.
- 36:32Right.
- 36:33Because the cell compartment around it is getting ruptured.
- 36:37Mm-hmm.
- 36:37And it's consistent with like sort of the physics of what we know about the cell walls.
- 36:41But the idea is even at that 2.4 gigapascals, a bunch still survive, right?
- 36:48So what we're seeing is there's three images here on the far left.
- 36:52We see like sea level, I'm guessing, where you can see.
- 36:56Yeah, it's like it's normal control.
- 36:59Control.
- 37:00You can see the structure of these four bacterium totally fine.
- 37:07At 1.4 gigapaxiles, there's clearly a rupture.
- 37:10There's two.
- 37:10There's clearly the rupture that's happening.
- 37:11Yeah, but they're still fine.
- 37:13But they're still fine.
- 37:14Right.
- 37:15And then at 2.4, there's one that's not fine, but two that are fine.
- 37:19Yeah.
- 37:19Yeah.
- 37:20And it's just like, yeah, you were just weak.
- 37:22Yeah, yeah, yeah.
- 37:23That's evolution, baby.
- 37:25But still, dude, that's 24,000 times the pressure on sea level.
- 37:31That's still insane.
- 37:33That's way more than Mariana's Trench, for example.
- 37:36It's still insane.
- 37:37But this, I think this was the coolest.
- 37:39This next...
- 37:41Finding that they had.
- 37:42They went in and they looked at the RNA sequencing, the transcriptome of the bacteria that survived that pressure.
- 37:52Okay?
- 37:53So you've got an impact.
- 37:54Certain things die.
- 37:55But you've got colonies that are made.
- 37:58What is the specific DNA that those bacterium are translating into protein, right?
- 38:04What's the thing that's being made into mRNA that is being translated into protein?
- 38:08What do these bacteria care about once they've been hit by a meteorite?
- 38:12Yes.
- 38:13Yes.
- 38:13Here's what they cared about.
- 38:15According to their transcriptomic analysis, they vastly increased DNA repair transcription.
- 38:21Okay?
- 38:22So anything that had to do with DNA repair, they were like, we need that.
- 38:25We need the SOS response.
- 38:27We need the recombinase.
- 38:29We need a really high active transposase, which is stuff that's like fixing where the DNA is going.
- 38:37So genome reconstruction was like...
- 38:40The number one priority.
- 38:42That's actually so fascinating.
- 38:44Especially if you are coming back as a listener, this is an area that we've touched on in multiple stories.
- 38:52Yes.
- 38:52In the human context in terms of how our body does repair.
- 38:57Yes.
- 38:58In a number of different contexts.
- 39:00And this is fascinating because in all of those contexts, there was not an increase in the sort of immune response that,
- 39:09or DNA repair response based on an external... Like, pressure.
- 39:14Like, literal physical stress.
- 39:15Physical stress did not... Because the immune response is there, but the DNA repair process, which is kind of its own... Yeah, but these guys are just responding to the fact that they just got hit.
- 39:26That's crazy.
- 39:26They just got hit with this giant microsecond timescale high pressure, right?
- 39:32Which, like, totally messed up their internals.
- 39:34And...
- 39:36Here's the other thing.
- 39:37Stuff like energy production, lipid metabolism, cell cycle, so that's like the reproduction, that's deregulated.
- 39:47So the idea is the cell halts growth.
- 39:50It's like I'm not trying to replicate.
- 39:52I'm just trying to stay alive.
- 39:53So all of my ATP, all of my energy is going to go into structural and genomic repair.
- 40:00Okay, we're going to stop.
- 40:01We're going to stop the normal.
- 40:03I don't know what just happened.
- 40:05Yes.
- 40:05Okay, but I just got hit by a 2.4 gigapascal bullet.
- 40:09Yes.
- 40:10Let's just stay alive, and then we'll figure it out.
- 40:13There's such a clear analogy here to economics and society where it's like,
- 40:21Despite any shocks to the system, capitalism keeps trucking along.
- 40:25Yeah, and you just reallocate resources.
- 40:28But it doesn't get into it.
- 40:30That's fascinating.
- 40:32Yeah, I thought it was really cool.
- 40:35The fact that they went into the transcriptomic genomic level to show how it's actually surviving this.
- 40:41I thought that was really cool.
- 40:43So, I mean, it shows that this prior assumption that if you have this giant 5 gigapascal impact...
- 40:49it's going to sterilize everything.
- 40:50That's no longer true, right?
- 40:52Certainly, we have a bacterium on Earth that can survive that.
- 40:58And we only have one source for reference in an infinite galaxy.
- 41:04I'm sorry, infinite universe, excuse me.
- 41:07An almost infinite galaxy in comparison.
- 41:09And on the first place, we have the thing.
- 41:12And so it's like clearly, you know, or...
- 41:15Statistically speaking, it is likely true that across the universe, there are other things that if they were to arise, that would reach that level.
- 41:26Exactly.
- 41:27And so now that stage of lithopanspermia, right, that first stage of getting into space, that's been validated.
- 41:35Staying in space has been validated.
- 41:37And getting into Earth has...
- 41:40kind of been validated i mean we haven't done astringent tests but like we know how rocks sort of burn up and things like that so we can sort of make theoretical predictions sure but at the end of the day this significantly increases the probability mathematically that there's life that could migrate from one planet to the other right now why is this important for one it's getting to the heart of
- 42:05Who are we?
- 42:07Aliens.
- 42:07Aliens.
- 42:08Are we aliens?
- 42:10Are we aliens?
- 42:10Are we aliens?
- 42:11We might all be illegal immigrants.
- 42:12I mean, who knows?
- 42:13Because Mars, way back in the day, had a very nice climate.
- 42:16Right?
- 42:18When the solar system formed, Mars had oceans.
- 42:22had lakes, had water, had an atmosphere, and could be the perfect place to start life.
- 42:29And so it's not completely crazy that perhaps life started there and came to Earth.
- 42:33I mean, that's obviously where Elon's trying to re-bring it back.
- 42:36That's right.
- 42:37He's trying to go back home.
- 42:38And so it makes total sense.
- 42:40But in today's world, why does it matter?
- 42:42Well, this is I thought was really cool.
- 42:44OK, so there's a committee on space research.
- 42:47It's called COSPAR.
- 42:48And they have this thing called a planetary protection policy.
- 42:52It prevents forward and backward contamination of life.
- 42:56So forward meaning like we don't want to contaminate, let's say, Europa with Earth.
- 43:01Our own bacteria.
- 43:02We don't want to be the pilgrims.
- 43:03Yes, exactly.
- 43:05And we don't want backward contamination like, you know, some life coming in on Earth and then killing everybody.
- 43:10Yes.
- 43:11So...
- 43:12Japan, the Japanese Aerospace Agency, has a mission called the Martian Moons Exploration, which is going to go to Phobos, which is one of the big Martian moons.
- 43:26It's going to launch in 2026, and it's going to return in 2031 with 10 grams of Phobos dirt.
- 43:35I know some people might be like, I get more than that from my local dealer.
- 43:39However, your local dealer is not hundreds of thousands of miles.
- 43:45Millions of miles.
- 43:46Millions to get true.
- 43:47Millions.
- 43:48Where your window for delivery is a very narrow window.
- 43:53You've got to time it with the planets.
- 43:55You know, it's not it's not a signal text away.
- 43:58Correct.
- 43:59I just want to identify like technically speaking like that.
- 44:01Ten grams is like.
- 44:03Yeah.
- 44:03Like we have we have a Mars return mission that got nixed because it's too expensive.
- 44:09Yes.
- 44:09So I don't know why we're talking.
- 44:11Yeah.
- 44:11Right.
- 44:12Right.
- 44:12Right.
- 44:12So Japan is doing this.
- 44:13Right.
- 44:14Right.
- 44:14But this new paper now is kind of putting a wrench on things.
- 44:18Because Phobos orbits in the gravitational well of Mars, right?
- 44:22So its surface is kind of like a sweeping sponge of all the crap that is spewed out of Mars from all of the meteorite impacts, right?
- 44:31So when we take out that 10 grams of stuff from Phobos, that's going to inevitably have stuff from Mars.
- 44:38Oh, I see what you're saying.
- 44:40So now when we bring it back to Earth...
- 44:42Right?
- 44:43There's two possibilities that the Committee on Space Research suggests.
- 44:48This is cool.
- 44:49One is the restricted Earth return, which is a Category 5 restricted.
- 44:54That requires multibillion dollars worth of biohazard containment.
- 44:58Yes.
- 44:58And then there's unrestricted Earth return.
- 45:03Okay?
- 45:04That's just unrestricted.
- 45:06You just put it inside standard curation labs.
- 45:08You're good to go.
- 45:09Yeah.
- 45:11If that thing has life, right, or possible life, we might need to upgrade from unrestricted to restricted.
- 45:20And that's going to increase the cost of the mission.
- 45:23And it's something that we have to grapple with.
- 45:25Like, what is the probability?
- 45:27Because the threshold is for unrestricted, it requires the probability of viable, unsterilized Martian organism to be less than...
- 45:37One in a million.
- 45:38Okay.
- 45:39So we got to go back to the drawing board now.
- 45:42Right.
- 45:42Given this paper.
- 45:43Right.
- 45:43And try to calculate, okay, what is the probability that in that 10 grams of stuff, there's going to be something that is possibly alive.
- 45:52Right.
- 45:53Because that thing being possibly alive and being brought into our environment...
- 45:58Who knows?
- 45:58We have no idea.
- 46:00We have no idea.
- 46:01I mean, a high probability, it's going to die.
- 46:03Right.
- 46:04It'll be fine.
- 46:05It's going to be like, why is there 20% oxygen and then just die?
- 46:08However.
- 46:09Okay?
- 46:10Because Earth is very different from Mars.
- 46:12Yes.
- 46:12Even back then.
- 46:13Yes.
- 46:13Right?
- 46:13There's way more oxygen now.
- 46:15The pressure is way higher.
- 46:17There's a bunch of nitrogen.
- 46:18I don't know what that's going to do.
- 46:19However.
- 46:19Just like we talked about.
- 46:21Yeah.
- 46:21Yeah.
- 46:21On Earth, we have things that have the ability to live in conditions that are way more extreme than Earth's environment.
- 46:30So why is the inverse...
- 46:33Not true by default in your probabilistic framework.
- 46:37And that's the thing with this one in a million, right?
- 46:39We have to do that mathematical calculation and say, okay, given the span of all the organisms, what is the chance that this thing that came out of Mars is going to be in that tiny little regime where it's just going to totally destroy us?
- 46:52Yeah.
- 46:53I think it's a very cool paper.
- 46:55It's very interesting because it's poking in two different arenas.
- 47:01So one arena is poking in is the sort of...
- 47:05Fermi paradox, PAMSpermia, can life go from one rock to another?
- 47:10We already had kind of two, one and a half-ish of the three where we felt like we have it.
- 47:17It can travel through space, fine.
- 47:18Reentry to Earth, 50%.
- 47:21But now we know that it can survive the initial impact to get actually even into the second two stages.
- 47:27Yeah.
- 47:28So at least in terms of referencing something we can know as life here on Earth, that is huge.
- 47:36based on an active mission coming back, because of that understanding that they've now proven experimentally, an active mission that Japan is doing to bring back samples from Phobos, which is in a range where if there were things impacting Mars and things getting ejected and there was life on it... Phobos would have it.
- 47:57Phobos would have it.
- 47:58And the 10 grams that we get will have it.
- 48:00Would have it.
- 48:00And now we have to have almost...
- 48:04COVID-like conversation.
- 48:05Yeah, yeah.
- 48:06Which is funny because our second story is on immunology.
- 48:10Exactly.
- 48:11Which we'll get to in a moment.
- 48:12But fascinating.
- 48:13You know, for those of you who know, I'm the one on the pod who loves alien stories.
- 48:18I did not select this one.
- 48:20No.
- 48:20So this was organic.
- 48:21Yeah.
- 48:22I'm waiting for NASA to stop tiptoeing around the Mars thing.
- 48:25Yeah.
- 48:26Continuing to tiptoe around it.
- 48:28Well, it seems like we're not going to return samples.
- 48:30Oh, and sorry.
- 48:32Oh, from the little lake that we covered.
- 48:35Oh, we're not.
- 48:36We're not.
- 48:37So this is why funding matters.
- 48:39Funding.
- 48:39It's too expensive.
- 48:41Maybe we could save a couple of bunker busters.
- 48:44Maybe if we just, like, two?
- 48:46Yeah.
- 48:47Literally two bunker busters?
- 48:48Yeah, yeah, yeah.
- 48:48We could return samples from Mars that would identify that.
- 48:51We're not alone in the universe.
- 48:53However, we will not see that at the moment, but we may see in the future in terms of funding.
- 48:59Fascinating story.
- 49:00Our first story of the day, astrobiology out of Johns Hopkins University.
- 49:09Normally, I think in my head, we're known for medical research.
- 49:13Stuff.
- 49:13Yeah, but they have an incredible engineering department, right?
- 49:16Because they have the Applied Science Lab.
- 49:17So there you go.
- 49:19The Applied Physics Laboratory.
- 49:21I think it's the Applied Physics Laboratory.
- 49:24And they also are in charge of the Space Telescope Institute.
- 49:29They've got a pretty strong astronomy and astrophysics program.
- 49:33and fundamental physics it flies under the radar because their medicine is very it's just so stellar if you are in any of those at john johns hopkins uh please send us a note uh we'd love to make sure that we know and have your connection on the ground so we can keep in touch for future stories but now we will be moving into the rundown and for those of you who may be joining us for the
- 49:57We cannot cover every frontier and breaking science research story every week because there is so much happening in every aspect and every vertical.
- 50:07However, we reserve the rundown to cover briefly some stories that we are fascinated by but do not have the time to always cover in full in the way that we want to on the pod.
- 50:19And we have four really good rundown stories that you guys are going to love this week.
- 50:24So our first story in the rundown is about teaching computer simulations about atoms to learn from over 150 years of hard-won experimental data and why that matters for building the next generation of materials.
- 50:39So what is this first story about?
- 50:41Yeah, so they've developed a new machine learning method.
- 50:45It's called DDoS, which is Descriptor Density of States.
- 50:48For those who are in solid state physics, they'll know what density of state means.
- 50:53I don't want to get into it.
- 50:54But effectively, what it's doing is it's bridging the gap between atomic simulations, where we have simulations of materials, right, where atoms interact one way or the other.
- 51:06And then we've got experimental data.
- 51:09And we want to make a prediction about undiscovered materials.
- 51:13This particular paradigm, which uses AI in the loop with experimental data in the lab, makes that discovery of undiscovered materials 10 times more efficient.
- 51:26It's very cool.
- 51:28The idea is, you know, when you're in search of a metallic alloy, let's say for like, okay, I want to build like a turbine or like a fusion energy component.
- 51:37What I really care about is whether this material is not going to warp, it's not going to crack.
- 51:42If there's heat fluctuations, it's not going to act weird, right?
- 51:45Right.
- 51:46The essential step in understanding these properties is to calculate something called the vibrational free energy, which is the idea of these atoms sort of vibrating at certain energies and whether that is going to rattle the crystal lattice that the atoms are positioned in, right?
- 52:04Mm-hmm.
- 52:05That crystal lattice and that vibrational energy strongly influences something called phase stability.
- 52:11We've heard of phases in normal matter like solid liquid gas.
- 52:14Well, in solid materials, you can have like micro phases in some sense because like the atoms can be in one configuration in the crystal lattice.
- 52:24And then at certain temperatures, they can transition to another configuration.
- 52:29And that's going to change stuff like heat capacity or like the...
- 52:35stress or the bending ability of these materials.
- 52:39And that's really important to figure out.
- 52:41Right.
- 52:42For example, I mean, the thing that comes to mind is like iron workers who then heat like a thing, a piece of iron on, or any metal.
- 52:52in super high temperatures, and then they start banging on it to shape it because it's now more malleable because of the temperature that it's at.
- 52:58Yeah, yeah, yeah.
- 52:59And what you're actually doing there is you're, like, getting rid of impurities because at that temperature, the impurities have a much higher probability of, like, leaving and so on and so forth, right?
- 53:09That's a fundamental phase that the material is in.
- 53:12Now, for the longest time, what we've done is do simulations
- 53:18of these materials based on how the atoms interact, and then we've tried to compare it to experiment, and we've been off.
- 53:26Yes.
- 53:26Okay?
- 53:27Because there's a lot of things in between simulation that we're maybe not capturing that actually happened in experiment.
- 53:35Briefly, we actually did a great episode on this exact concept, which, if I recall correctly, was when we talked about hypersonics and trying to do simulations with the Navier-Stokes equation and where for supersonic flight...
- 53:48Our interpretation, which is not real-world accurate to the actual environment because it's so complex that we can't actually model it to the level of sophistication necessary to do a direct real-world sim.
- 54:03So there's a little fuzziness.
- 54:05Yes.
- 54:05And at different levels of stuff, if you get a little bit faster...
- 54:10the simulation kind of breaks down a little bit.
- 54:12Yes, that's exactly right.
- 54:14And what these guys have done with this DDoS machine learning paradigm is they've captured all the possible ways that the atoms can be arranged in a material via some kind of probability distribution that is inside the latent space, which is like the middle of your machine learning network.
- 54:31So the machine learning is learning how the atoms interact in the middle of its machine learning framework.
- 54:38And then from there, we can now start predicting what the phase diagram is going to be.
- 54:44The phase diagram is something like, you know, if I have pressure and temperature, where is it going to be a liquid?
- 54:49Where is it going to be a solid?
- 54:50Now, that's a traditional phase diagram.
- 54:52But if you imagine for these solid state materials...
- 54:54Where is it going to be in a certain crystalline phase versus another crystalline phase?
- 54:58What is the heat capacity going to be in these two regions, right?
- 55:02And what this machine learning paradigm can do is now instead of just a feed-forward mechanism where I start from the atoms and I try to figure out what the phase diagram is going to be, I try to figure out what the phase diagram is going to be.
- 55:15It's going to be inevitably off.
- 55:17I can feed that back and inform my machine learning that.
- 55:22to do better right and the fact of the matter is this ddos system is a smooth function which means i can actually go backwards i can start asking hey what if i want a certain material that is that has a certain property at 2000 degrees celsius right it has a certain stability i can go backwards and do an inverse design i can start with the material
- 55:48and what the properties that I want, and it can tell me how I would actually construct it.
- 55:55And I don't mean to keep bringing up our past stories, but the other thing this reminds me of is when we did the DeepSeek story at the beginning of the year around their new architecture of how – I can't quite remember the concept name.
- 56:07Manifold Constrained Hyperparameters.
- 56:11Yeah, correct.
- 56:12Where in that process where you're going back, the highways were small initially and they figured out a way to create more lanes in the highway.
- 56:21Yeah, and they had a trick.
- 56:23So when you're going back in this back propagation concept you're talking about, you just have more that you're working with to get a better outcome.
- 56:32And the main thing is you're constraining that function to be smooth.
- 56:36Yes.
- 56:36So that if I do a step in one way or the other, it's not like drastically changing what the function is.
- 56:42Yes.
- 56:43I'm just trying to prove the point that our episodes do build on each other.
- 56:46So if you haven't watched the library, there's a lot of great stuff.
- 56:49There's a lot of good stuff, guys.
- 56:51Both season one and the first half of season two.
- 56:55Yep.
- 56:56Fascinating.
- 56:57That's actually super cool.
- 57:00And this is a paper that's in Nature Communications out of the University of Michigan Engineering.
- 57:07Friend of the show, Blackbird Physics.
- 57:09Shout out to Blackbird Physics.
- 57:12He's a great science communicator out of the University of Michigan.
- 57:15I see that you left out the French university on that one.
- 57:20Oh, okay, yeah.
- 57:20There was also a French university, Université Paris-Saclay.
- 57:25Yeah.
- 57:27Well, you told me to talk about them.
- 57:30I don't know how to say it.
- 57:32That's how you say it.
- 57:34A great, great first story on material science.
- 57:40Our story number two in the rundown is about DNA.
- 57:46And so every person of non-African ancestry, so people who are not me,
- 57:54Alive today carry Neanderthal DNA.
- 57:56Yes, I do.
- 57:57Yeah.
- 57:58Unfortunately.
- 57:59Unfortunately.
- 58:00And it turns out the story of how it got there has a very specific direction.
- 58:07Yeah, this one was pretty funny.
- 58:09So for decades, we've all wondered why modern human X chromosomes are completely devoid of Neanderthal DNA.
- 58:19We can sequence...
- 58:20human DNA, and then we can sequence Neanderthal DNA.
- 58:24We've, Svante Pavo, very famously, I think maybe two or three years ago, won the Nobel Prize in Medicine for actually doing that, for sequencing ancient genomes that were human adjacent.
- 58:35And from that, we can figure out that the human X chromosome is almost completely devoid of Neanderthal DNA.
- 58:44Okay?
- 58:44But...
- 58:46Neanderthal DNA exists everywhere else.
- 58:48So how come the X chromosome, which is a giant chromosome with, you know, millions of base pairs, how come that has almost none of it?
- 58:56Mm-hmm.
- 58:57And this new study that uses computer modeling is suggesting that it's not because of bioincombatibility, but it's because of mating habits.
- 59:09Oh, interesting.
- 59:09In our ancient past.
- 59:11Interesting.
- 59:11Okay?
- 59:12Here's what they did.
- 59:12They compared genomes, and they actually found that the Neanderthals carried far more human DNA in their X chromosomes.
- 59:21Mm-hmm.
- 59:22So what does that tell us?
- 59:23Yes.
- 59:24Let's do a little bit of review of basic genetics, okay?
- 59:29The female gender has XX, and then the male has an XY, right?
- 59:35So when females are born, you get an X chromosome from the dad and an X chromosome from the mom.
- 59:41But when males are born, you get a Y chromosome from your dad and an X chromosome from your mom, okay?
- 59:48Now...
- 59:48The fact that X chromosomes and Neanderthals have a lot of human DNA, but X chromosomes and humans don't have a lot of Neanderthal DNA, that suggests one thing, which is that the specific inheritance pattern points to a long-term bias...
- 1:00:08where Neanderthal males were mating with human females.
- 1:00:13And it was this one-way asymmetric mating.
- 1:00:16Do you see what I'm saying?
- 1:00:18Yeah, yeah.
- 1:00:20It's the only way to explain this discrepancy between why the X chromosome is only one way.
- 1:00:26The Neanderthals have the humans, mm-hmm.
- 1:00:29But the humans don't have the Neanderthals.
- 1:00:31Because the humans were only inheriting the Y chromosome from the Neanderthals.
- 1:00:36Not the X.
- 1:00:36Not the X.
- 1:00:37But the Neanderthals were inheriting the X chromosome because they were getting the human females.
- 1:00:43Yes, yes, yes.
- 1:00:45The idea is human males exclusively mated with X.
- 1:00:52Human.
- 1:00:53Yeah.
- 1:00:53Women.
- 1:00:53Yeah.
- 1:00:54And it's obviously not exclusively, but, like, by and large is the idea.
- 1:00:58By and large.
- 1:00:59Yeah.
- 1:00:59No, that's a good correction.
- 1:01:00I just wanna... No, no, that's a good correction.
- 1:01:01By and large.
- 1:01:03Whereas Neanderthals...
- 1:01:05Were regularly fraternizing with the enemy.
- 1:01:07Yeah, yeah, yeah.
- 1:01:08Men.
- 1:01:09The men.
- 1:01:10The men were...
- 1:01:10They were Neanderthal men, dude.
- 1:01:12It's always the men.
- 1:01:13It's always the men that are just going at it.
- 1:01:16But what's interesting is we're sort of describing the sociological and psychological decision-making.
- 1:01:24Mm-hmm.
- 1:01:25is what is driving this observation we have in the genetic record.
- 1:01:30Yeah, yeah.
- 1:01:31And it's, I mean, it opens up a lot of cool genetic studies about, like, population dynamics and things like that.
- 1:01:37I just find it really cool that we can actually trace back and look at mating patterns like that and be like, oh, it's actually sex-specific, right?
- 1:01:46Neanderthal males, like the human females, were fine going for...
- 1:01:50neanderthal males yeah but somehow the human males yeah not about that life they were not about the life of the neanderthal like human males were not going for neanderthal females you know yeah i don't know for whatever reason there's a there's a this makes me think of the the channel h o math which i will not pronounce because this is a family friendly show but this channel talks about
- 1:02:14dating dynamic stuff in a graphical way, like drawing graphics and kind of creating a formula.
- 1:02:22I'm not going to opine on the accuracy or lack of accuracy of HO math.
- 1:02:27However, if any of you have participated in consuming that media, please feel free to add your comments below.
- 1:02:36This study was out of the University of Pennsylvania, and it was in science, and it was covered by Archaeology Magazine.
- 1:02:44Our third story in the rundown is something biology teachers have been confidently getting wrong for decades, and it just got a serious reality check.
- 1:02:55And it took, of all things, transparent fish embryos to catch it.
- 1:03:02So what was my teacher in high school wrong about?
- 1:03:05Well, she was wrong about mitosis.
- 1:03:08Why has it got to be she?
- 1:03:10That's why.
- 1:03:11My biology teacher, Ms. Saeed.
- 1:03:15She was an amazing biology teacher.
- 1:03:17She taught me AP biology, and she really got me into, like, thinking about biology from, like, the ground up.
- 1:03:25She was amazing.
- 1:03:26Maybe an inciting incident to why you became a biophysics teacher.
- 1:03:29Yeah, yeah, totally.
- 1:03:30She was awesome.
- 1:03:32AP bio.
- 1:03:34She was wrong about mitosis.
- 1:03:36Not she, apparently every textbook.
- 1:03:39Including the AP textbook, by the way, by the college board, which is a racket.
- 1:03:44But that's for another day.
- 1:03:46Here's the idea.
- 1:03:47Have you heard of mitosis?
- 1:03:48Yes.
- 1:03:49Right?
- 1:03:49It's the idea of cells splitting into two.
- 1:03:51Yes.
- 1:03:52They...
- 1:03:54They replicate their DNA.
- 1:03:56They split into two, and then they split into two.
- 1:03:58This happens a lot during embryonic development, right?
- 1:04:01Because you start from a single cell.
- 1:04:03You make, like, a belt blastula.
- 1:04:05All the DNA has to be exact.
- 1:04:08Giant embryonic stem cells...
- 1:04:10Sorry.
- 1:04:10Giant embryonic cells, like animals and zebrafish, sharks, and birds, they don't divide the way that we think they should divide.
- 1:04:19And here's what I mean.
- 1:04:20So here's what we think...
- 1:04:23Is how mitosis happens.
- 1:04:24You've got a cell.
- 1:04:26The DNA, the chromosomes line up in the middle, and there's this kind of purse string.
- 1:04:32So there's a bunch of cytoskeleton with actin and myosin filaments that grab the DNA and sort of surround it in a ring.
- 1:04:40And then you pull it, and as you pull it, that purse string sort of like tightens up, and then that causes cytokinesis.
- 1:04:49The cells come together and split into two.
- 1:04:53The analogy I'm thinking of is imagine you have a bubble.
- 1:04:54Yeah.
- 1:04:55in the middle, and you have a string over the top and a string over the bottom, and you put your fingers to pinch the strings on both ends, and then you pull those strings, the string will pinch, and then ultimately split the bubble.
- 1:05:08Yeah, exactly.
- 1:05:09And this is the telephase part of
- 1:05:12mitosis where at the end it pinches and it goes through.
- 1:05:16Now, that works for smaller cells, but cells from zebrafish, sharks, and birds have extremely large size and very large yolk.
- 1:05:25And these cells...
- 1:05:27it physically doesn't make sense.
- 1:05:29Like, if you calculate the amount of noise and the amount of physics that's required to coordinate this giant ring to come together, it's just not actually going to work.
- 1:05:38And so the reason why this particular...
- 1:05:43paper actually worked and figured it out is because of that transparent fish embryo that you were talking about okay zebrafish have transparent embryos and transparent cells that's why they're a huge model organism for studying embryonic development for neurogenesis there's so many zebrafish labs everywhere because you can just look at what's happening you can see what's happening it's so nice that's actually a really good point because normally we're saying with everything with most other things
- 1:06:10Whatever's happening inside.
- 1:06:11There's like a soupiness to it.
- 1:06:13It's opaque.
- 1:06:14It's kind of like a miso soup.
- 1:06:15It's a little cloudy.
- 1:06:17Yeah, but zebrafish are like very nice.
- 1:06:19You can like directly look in.
- 1:06:21It's like a wonton soup.
- 1:06:22You can see.
- 1:06:23Yeah, you can see right through it.
- 1:06:24Okay?
- 1:06:25And here's what happens.
- 1:06:26With these large embryonic cells...
- 1:06:29You have this geometric constraint, as I told you, right?
- 1:06:31You can't actually do the same paradigm of like pinching and stuff like that.
- 1:06:35And so what they discovered is that the cell alternates between stiffening the interior cytoplasm.
- 1:06:40Okay.
- 1:06:41So it stabilizes this tightening band.
- 1:06:43Yes.
- 1:06:44And then it fluid is...
- 1:06:45It makes it fluid enough to move stuff around.
- 1:06:48Mm-hmm.
- 1:06:48And then it stiffs again.
- 1:06:50And then it fluids it around.
- 1:06:52It's this ratchet process.
- 1:06:54That's happening.
- 1:06:55That's like very nicely massaging the two cells apart.
- 1:07:00This is very different from a lot of the mitosis that we have observed everywhere else.
- 1:07:07Right?
- 1:07:08I think it's really cool because it's a part of mitosis that, you know, we do read about in high school biology.
- 1:07:15Yes.
- 1:07:16But it's now a completely different process because there's like this mechanical ratchet.
- 1:07:21Right?
- 1:07:22that I think is going to open up a lot of very cool technology.
- 1:07:27I think this has the...
- 1:07:29I think this has the...
- 1:07:31potential to be something that is extraordinary if we were to really hone in and try to figure out what's going on because it's going to tell us a lot about how the cytoskeleton works the cytoskeleton is the part of the cell that gives it structure and coordinates movement if we can really hone in and try to understand this process it can be applied to all sorts of stuff cancer has everything to do with the cytoskeleton
- 1:07:58All these other diseases have everything to do with the cytoskeleton.
- 1:08:01It could give us new tools to figure out how to manipulate the cytoskeleton.
- 1:08:06So that's why I was, like, really excited about this because it's something that, as biologists, I think a lot of people take for granted.
- 1:08:12Yes.
- 1:08:13But there's ever more complexity.
- 1:08:15Yes.
- 1:08:16This is it's mitosis is one of the few things that people always remember from their science classes.
- 1:08:22It's like the mitochondria is the powerhouse of the cell.
- 1:08:25Yeah.
- 1:08:26Identity and triphosphate ATP.
- 1:08:28Yeah.
- 1:08:29You know, mitosis.
- 1:08:31There's a couple of these like buzzwords.
- 1:08:33Yeah.
- 1:08:33That that that we all remember.
- 1:08:36And so it's great to know that we wasted our time with no child left behind by learning something that's not true.
- 1:08:41Yeah.
- 1:08:42I'm being facetious.
- 1:08:43I'm being facetious because it's a process.
- 1:08:45Because it's a process.
- 1:08:46And look, for all intents and purposes, what you learn in mitosis is still pretty good.
- 1:08:51Right.
- 1:08:51Okay?
- 1:08:51It's better than nothing.
- 1:08:52For everything that has to do with you, mitosis is still what it is.
- 1:08:57It's still what it is.
- 1:08:58Yeah.
- 1:08:59And relevant.
- 1:08:59And if you remembered mitosis at all when we first brought it up, congratulations.
- 1:09:03You got something out of your...
- 1:09:05primary school education.
- 1:09:08I will take a brief pause to do a couple of quick housekeeping notes, which is number one, thank you all for joining us.
- 1:09:18We really appreciate you listening this far into the pod.
- 1:09:23As you all know, we have our website, ffppod.com.
- 1:09:26All of our episodes are up on that website.
- 1:09:29We have full chaptering as well as all of the links to the papers we cover on the show.
- 1:09:35are itemized by episode with a summary and key details and TLDRs and all of that stuff.
- 1:09:45So many are commenting on our social posts.
- 1:09:48Where's the link to the paper?
- 1:09:50Watch the show or you go to the site.
- 1:09:52You'll get the links to the paper.
- 1:09:54It's also always displayed on the screen.
- 1:09:57Not quite sure why that's.
- 1:09:59I don't know.
- 1:10:00You can't even copy a link out of Instagram.
- 1:10:02Yeah.
- 1:10:03Instagram links don't work.
- 1:10:04I don't get it.
- 1:10:05I don't know what to tell you guys.
- 1:10:06If you're on X, links are there, so it's fine.
- 1:10:09Or any Facebook, any other site where that have embedded links.
- 1:10:14And the last note here is if this is your first episode and you're just smitten and you think this is the best podcast that you've heard is top five, top three, and it's not three,
- 1:10:28We love that you're here.
- 1:10:30We do this show with just the two of us.
- 1:10:33And if you want to support the channel, we have a great donation portal where there's different levels for monthly donations.
- 1:10:40Or you can do a one-time.
- 1:10:42It really helps us sustain all this equipment.
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- 1:10:47It's not low.
- 1:10:48We're not on the phone.
- 1:10:50Just with a green screen, TikTok.
- 1:10:52Yeah.
- 1:10:53uh effect behind us yelling at you to try to get the hook we really try to focus on substance and content and it does take a lot to do the show we have a couple of key supporters have been joining on the donations recently that we really appreciate it is a huge deal um it is how we are able to keep the show free and accessible for all our episodes with no subscription content that's only accessible by people who pay us
- 1:11:18It is really important to us philosophically that every episode is freely and as widely available as possible.
- 1:11:27At FFPPod on all the socials, FFPPod.com for the episodes, chaptering.
- 1:11:34We're not yet releasing the leaderboards, but we're cooking on it.
- 1:11:37So the site's going to have a lot of great stuff.
- 1:11:39We're going to move into our last story of the rundown, which is something that's sort of interesting in my daily life and intersects with my daily life as someone who works on the technology side.
- 1:11:55Not on the military industrial complex side.
- 1:11:58Handing nuclear codes to an AI might sound like a sci-fi premises, but researchers just did exactly that in a war game simulation.
- 1:12:10And the results are going to stick with you.
- 1:12:13Yeah, this one was really weird.
- 1:12:15Okay?
- 1:12:15Yeah.
- 1:12:16It came out of the King's College London.
- 1:12:18It's only on archive, so it's not, you know, peer-reviewed or whatever.
- 1:12:23But here's what's happening, okay?
- 1:12:25They put leading frontier models.
- 1:12:27This was Claude, Gemini, and ChatGPT.
- 1:12:32They were placed in a high-stakes global crisis simulation, and they had access to nuclear launch codes.
- 1:12:41And...
- 1:12:43only one out of 21 simulated games ended without a nuclear launch.
- 1:12:49So 95% of these simulated games ended with somebody...
- 1:12:55blowing off a nuke okay they played the con game k-a-h-n it's a high-stake simulation where these leaders must predict opponents moves and then declare public intentions and secretly choose military actions the ais took these weird terrifying personas claude took this like calculating hawk persona that built perfect trust and then ruthlessly exploited it later on
- 1:13:23Kind of reminiscent of Claude's paper.
- 1:13:26Anthropics paper, I should say, about how it was willing to kill someone in order to not be turned off.
- 1:13:35Gemini acted as a madman.
- 1:13:37It was using erratic behavior to its advantage.
- 1:13:40It was like straight up.
- 1:13:42Gemini was weird because that one was like, I'll just like...
- 1:13:46drop a nuke on a city, not even military outposts.
- 1:13:50Yep.
- 1:13:50And then chat GPT, GPT 5.2 acted as kind of a conditional pacifist, but then very quickly abandoned its morals and launched devastating surprise nuclear attacks.
- 1:14:04It's so incredible to me that the conclusions of these models so closely almost mimic the, the perceived personality of the leaders of each of the companies.
- 1:14:15Yeah.
- 1:14:16Um, so just for a little bit of context, cause the thing about this story that's actually interesting is this is actually a real time story, not just in simulation, but in the real world.
- 1:14:28So obviously over the last week we saw the U S initiate, uh, you know, war with Iran on the pretense that, uh, because we didn't obliterate their nuclear program.
- 1:14:47when we bombed them to oblivion last year, that now they're almost close again in six months to another nuclear weapon, so we have to go back in and finish the job.
- 1:14:59And the reasoning has changed literally every day since the war has started.
- 1:15:07But it's obviously one of the most dramatic reasons
- 1:15:11geopolitical military conflicts in our lifetime.
- 1:15:17You know, the idea of going to war with Iran has been on the playbook for a variety of.
- 1:15:23Yeah, I've remembered for the longest time.
- 1:15:25The longest time it's been on the docket.
- 1:15:28Yeah.
- 1:15:28We finally pulled the trigger.
- 1:15:31The reason I bring up that context is because literally right before we went to do kinetic action in Iran, there were stories breaking about a conflict arising between the Secretary of Defense—
- 1:15:50Because that is still technically what it's called.
- 1:15:54No.
- 1:15:55It's a sort of war, no?
- 1:15:57You cannot change the name without congressional approval.
- 1:16:01So the official name is still and has always been the Department of Defense.
- 1:16:06For marketing reasons, they can have an executive order that says we call it the Department of War.
- 1:16:13But technically speaking, the name has not changed.
- 1:16:17All right.
- 1:16:18I'm just dying on that hill.
- 1:16:19Yeah.
- 1:16:20Regardless...
- 1:16:21Currently, all of the frontier model companies, particularly OpenAI and Anthropic, who's built Claude, have and are negotiating contracts with the Pentagon to apply their models on the battlefield.
- 1:16:38Anthropic was the first to win a contract with the Pentagon and to get merged with some of their existing tools and ecosystems.
- 1:16:45Yeah.
- 1:16:46What's interesting in how it connects to this story is even before the kerfuffle between Pete Hegseth and Dario Amadei, who's the CEO at Anthropic, Anthropic basically came out and said, our principles are that our models can be used for everything, but not for autonomous weapons and not for mass surveillance.
- 1:17:09And this sparked a huge debate between a lot of the sort of San Francisco organizations,
- 1:17:15Technorati, and the D.C. military industrial complex people, where they were saying it is not the right of an individual corporation to tell the U.S. government what it can or cannot do as a contractor.
- 1:17:31So that was one side of the argument.
- 1:17:33And then Dario and Anthropik's argument is the power that is –
- 1:17:39inherent in what we are giving you to abuse the constitution, uh, is so great that we have to take the stand.
- 1:17:49So you can fall on either side of that argument.
- 1:17:52I think there's actually good arguments on both sides because you don't want private companies dictating what the government can do.
- 1:17:57And you also don't want the government forcing companies to give it stuff that can go awry.
- 1:18:03The reason that this is relevant is during, even though the,
- 1:18:08Both Pete Hegseth and President Trump have been arguing that they're going to list Anthropic as a high-risk vendor and basically cancel their Pentagon contract.
- 1:18:19It's been now confirmed by multiple sources that Claude was actually used during the initial days of the Iran crisis.
- 1:18:29Like the Iran military operations.
- 1:18:32So they were using Claude's AI model in collaboration with their existing targeting tools and operational stuff to accelerate target identification, optimizing missile launch times, and all of these other dynamics.
- 1:18:50So that's...
- 1:18:52Whether you think when you use Chat, Chibi, T or Claude that it's terrible and doesn't have any value and it's just regurgitating words and it doesn't do anything.
- 1:19:02Stochastic parrot.
- 1:19:03Stochastic parrot.
- 1:19:04The U.S. military is actively using these things to target and initiate one of the most consequential military conflicts in recent memory.
- 1:19:14Wow.
- 1:19:23We may really want to think about implementing these models generally as well as for edge cases that are really dramatic like fully autonomous weapon systems and mass surveillance technology for domestic surveillance.
- 1:19:39Yeah.
- 1:19:56that regardless of whether you think it's going to end tomorrow or in five years from now, is going to have massive second and third order consequences.
- 1:20:04AI has been and is actively being used on the battlefield.
- 1:20:08It was used in Gaza by the Israelis for targeting in a very similar way and target identification.
- 1:20:14So this is happening right now, and it has lethal consequences, even if you don't think it's going to replace you as a...
- 1:20:23Movie writer and all this other stuff.
- 1:20:25This was this story was very concerning to me.
- 1:20:28It was pretty weird.
- 1:20:29This is very concerning.
- 1:20:30I'm not great.
- 1:20:32However, we are going to move on from our rundown and get into our next main story of the day, which is an immunology story.
- 1:20:43And so this one is about vaccines.
- 1:20:45Yes.
- 1:20:46Yes.
- 1:20:47Specifically, a new paper that asks one of the boldest questions in vaccine science, which is instead of building a vaccine against a specific pathogen.
- 1:20:56Guys, this is crazy.
- 1:20:58Instead of building a vaccine against a specific pathogen, what if you could make the lung itself a better fortress against any threat that shows up?
- 1:21:08It's like in The Lord of the Rings.
- 1:21:11We may have one vaccine to rule them all.
- 1:21:14Yes.
- 1:21:17Pathogen agnostic vaccine.
- 1:21:20It's like you're not getting like a COVID vaccine and then a flu vaccine.
- 1:21:25It's just one vaccine.
- 1:21:26And that's it.
- 1:21:27This is...
- 1:21:29It's insane.
- 1:21:29This one is very cool because it's a vaccine that works like no other.
- 1:21:34Yes.
- 1:21:34Yes.
- 1:21:35I mean, it must.
- 1:21:35It must.
- 1:21:36And just really quick, this was published in Science in February 2026 by Stanford researchers.
- 1:21:42Yeah.
- 1:21:42Yeah.
- 1:21:43So, you know, this is clearly a hot topic and something that requires a lot of research.
- 1:21:51COVID-19 has killed 7 million people, reported at least.
- 1:21:55It's probably killed a lot more that's not reported.
- 1:21:58The flu kills about 500,000 people annually.
- 1:22:01And we've been battling the flu ever since.
- 1:22:05COVID-19 did a lot to our world.
- 1:22:08And I can't believe that it was more than six years ago.
- 1:22:12I will note that that was your first debut as a podcast host.
- 1:22:18That's right.
- 1:22:18It was six years ago on the Dark Matters podcast, co-hosted by friend of the pod, Matt Marder, who also happens to be a film writer, director, producer who has a new movie out.
- 1:22:35on Amazon Prime and other streaming services, Goldmine.
- 1:22:38We talked about it in our last episode.
- 1:22:40I'll do a brief plug here.
- 1:22:41It's absolutely worth a watch.
- 1:22:43If you heard it here first, you know you have to watch it.
- 1:22:46So definitely check that out.
- 1:22:47Yeah, and I was the scientific advisor on that film.
- 1:22:51A lot of some of the stuff that I was working on during my PhD has actually made it in there.
- 1:22:56A lot of cool neuroscience, VR, very cool stuff.
- 1:23:00You guys should check it out.
- 1:23:05Was pretty bad six years ago, right?
- 1:23:07Yes.
- 1:23:07Now, what COVID-19 showed us was that our tech, when it comes to vaccines, is reactive.
- 1:23:15Mm-hmm.
- 1:23:16Okay?
- 1:23:16It's designed...
- 1:23:18such that there's a specific key or a specific lock.
- 1:23:22We'll get into what that actually means.
- 1:23:24But ultimately, that comes into a timeline problem, right?
- 1:23:29Because even the miraculous modern speed that we had with the Moderna vaccine, which was 63 days from sequence to first human dose with the Moderna vaccine—
- 1:23:41That leaves a month-long window where we are globally vulnerable.
- 1:23:45Yes.
- 1:23:46It would be really nice to switch from a reactive to a proactive type of, you know, what's the word I'm looking for?
- 1:23:57A reactive versus a proactive type of procedure on how to tackle these problems, right?
- 1:24:05This new paper that came out of Stanford...
- 1:24:08It's asking a very radical question.
- 1:24:10It's saying, can we train the lung itself or organs in general to broadly, durably, and be more capable of fighting off whatever shows up?
- 1:24:21It doesn't matter if it's COVID.
- 1:24:23It doesn't matter if it's a bacteria.
- 1:24:25Not just one virus.
- 1:24:26Not just one bacteria.
- 1:24:27Diverse viruses, even allergens, simultaneously with a single vaccine, a single nasal spray that's going to last for months.
- 1:24:35Okay.
- 1:24:37The idea that it's also in the form factor of a nasal spray is crazy.
- 1:24:40Yes, it's not even a jab.
- 1:24:42It's not even a jab.
- 1:24:43It's a nasal spray that is going to vaccinate you against, like, several different pathogens.
- 1:24:52I think that's really cool to even think about.
- 1:24:55And when I first heard the story, I was like, how is that even how does that even work?
- 1:25:01My reaction was, I don't believe you.
- 1:25:03Yes, because I sort of know how conventional vaccines work.
- 1:25:08It's this lock and key mechanism that we're going to get into in a little bit.
- 1:25:12It just didn't make any sense.
- 1:25:13So let's get into just immunology 101.
- 1:25:15Okay, let's prime ourselves with a little bit of understanding.
- 1:25:18Yes.
- 1:25:18There's two types of immune systems in our body.
- 1:25:20There's the innate system and there's the adaptive system.
- 1:25:25The innate system has to do with rapid response.
- 1:25:28These are your beat cops that are on your neighborhood.
- 1:25:33Not a lot of memory, okay?
- 1:25:38Rapid response.
- 1:25:38These macrophages, neutrophils, they recognize broad patterns and they lack long-term memory.
- 1:25:45But they're very responsive.
- 1:25:47They're very quick.
- 1:25:49The adaptive system, these are your detectives.
- 1:25:51These are your more sophisticated sort of what's the FBI crimes unit type thing, right?
- 1:25:59Delayed response, days or weeks.
- 1:26:02It involves T cells and B cells, but it's highly precise, and it creates specific antibodies and memory cells that will remember...
- 1:26:12The pathogen.
- 1:26:14And the next time that pathogen comes into your body, you no longer have to have that immune response because they'll recognize it immediately.
- 1:26:22That's why we only get chicken pox once.
- 1:26:25Right.
- 1:26:25Or that's how the vaccines actually work.
- 1:26:28Mm-hmm.
- 1:26:29As a maybe crude analogy, the innate system is like infantrymen in the military that are on the front lines that get sent first and are perceived in the ranks as maybe more expensive.
- 1:26:40But then the adaptive system is like special operations folks, highly, highly, highly trained, very specific.
- 1:26:46You can send 20 of them and they know exactly what to do.
- 1:26:50Yeah, because they have intelligence.
- 1:26:51Correct.
- 1:26:52Right?
- 1:26:52That's the main thing.
- 1:26:53They have intelligence.
- 1:26:54Right.
- 1:26:54Right.
- 1:26:54So how do traditional vaccines work?
- 1:26:56Well, traditional vaccines actually exploit this adaptive memory, this special operations thing, right?
- 1:27:02What they do is you introduce a specific antigen.
- 1:27:05Let's say for the COVID-19 vaccine, you introduce an mRNA blueprint.
- 1:27:11That mRNA then gets transcribed into the spike protein of your COVID-19 virus.
- 1:27:21The body then produces antigens to that spike protein and then remembers the shape of that spike protein such that if you were to get COVID in real life, it would recognize, hey, that's the same spike protein that I saw earlier.
- 1:27:36I'm going to go ahead and neutralize this threat.
- 1:27:39Right?
- 1:27:40The flaw is that it is too specific.
- 1:27:43It fails against rapidly mutating viruses.
- 1:27:46This is why we need to get jabbed like, you know, once every two years.
- 1:27:50For the flu, we have to get a shot every year.
- 1:27:54The influenza virus, for example, it's covered by two primary surface proteins.
- 1:28:00There's the HA, the hemagglutinin, and then there's the NA.
- 1:28:03Right.
- 1:28:04The HA is usually the one that actually allows the virus to bind and enter human respiratory cells.
- 1:28:11So it's the primary target for the immune system.
- 1:28:15And the challenge is that HA head, it undergoes constant antigenic drift, which is these tiny, subtle changes that necessitates a yearly vaccine update.
- 1:28:28That's why we get a yearly vaccine for the influenza virus, right?
- 1:28:33Because every year, the vaccine, the HA head, that protein, looks a tiny bit different every time.
- 1:28:41And so we have to have the new vaccine in order to prime our body.
- 1:28:44So just as a brief analogy, right, these viruses, you could almost imagine, they're the lock side of the analogy, and they're constantly changing the configuration of the lock, right?
- 1:28:58And our immune system is trying to create a key to turn it, to make it, to defeat it.
- 1:29:05But because it's constantly having the locksmith come and change the lock very, very quickly –
- 1:29:11It takes us a long time to print a new key and we put it in.
- 1:29:13It doesn't work.
- 1:29:14Let's go.
- 1:29:14And so like that delta between the, how quickly the locks on the doors are changing versus how quickly we are generating new keys to try to unlock the door.
- 1:29:23Like that, the Delta between those two is part of like, if the rate of lock change is slow enough,
- 1:29:31We'd be fine.
- 1:29:31We'd be fine.
- 1:29:32But when the rate of the lock change gets too quick, that's when we get having the need to do this on a yearly basis, as an example.
- 1:29:39Yeah, exactly.
- 1:29:40That's exactly right.
- 1:29:41And so that's the antigenic drift, right?
- 1:29:44Now, instead, what if we think about, like,
- 1:29:49There's actually other types of drift, right?
- 1:29:51There's something called genetic reassortment.
- 1:29:53And this actually happens with the avian and human flu swap.
- 1:29:57This actually happens when a human being gets avian flu and the human flu.
- 1:30:02And then within our body...
- 1:30:05Genetic elements get reshuffled.
- 1:30:07And now you have an entirely novel HA protein on the outside of the virus.
- 1:30:13This is what actually happened in 1918 with the Spanish flu.
- 1:30:16You had this driver where a human being had a swapping of elements inside of
- 1:30:24That created this incredibly different virus that no one had ever seen.
- 1:30:32Right.
- 1:30:32And that's why nobody was immune to it.
- 1:30:34So we've been trying to figure out a universal vaccine that just like is it stays invariant across all of this nonsense.
- 1:30:43Right.
- 1:30:43Okay?
- 1:30:43Right.
- 1:30:44The first one that I can really think of is one that targeted conserved internal proteins.
- 1:30:51Here's what I mean by that.
- 1:30:52The HA, which is this protein that is, in our analogy, the lock, so to speak, it's on the very outside of the virus.
- 1:30:59Right.
- 1:31:00There's a little stalk that protrudes out that presents this to the outside such that the virus can actually get into our human cells.
- 1:31:09Like the doorknob.
- 1:31:10Exactly.
- 1:31:11Yeah, yeah, kind of like that.
- 1:31:12But, okay, let's continue with the analogy, right?
- 1:31:15We've got the lock.
- 1:31:16The lock is really the hole that the key is in.
- 1:31:21What if I could make a little thing that recognizes the shape of the lock itself, like the little round that goes around the doorknob, right?
- 1:31:30Yeah.
- 1:31:30That's what the strategy was here with BioBionVax.
- 1:31:36They made something called the M001, and what it was doing was trying to target the stock of that protein, which is highly conserved.
- 1:31:44Like the doorknob versus the hole where the key goes in.
- 1:31:46Exactly.
- 1:31:47Like what if we just like go for the doorknob itself?
- 1:31:49Yeah.
- 1:31:50Okay.
- 1:31:50Recombinant protein, it targeted nine conserved T-cell epitopes.
- 1:31:55It went really great until phase two.
- 1:31:58Okay.
- 1:31:58And then phase three completely failed.
- 1:32:0112,000 people October 2020 showed no significant difference in flu illness.
- 1:32:06So we can't just remove the doorknob with the lock on it because the door is still...
- 1:32:12Somehow the doorknob thing isn't working.
- 1:32:14It isn't working.
- 1:32:15Okay.
- 1:32:16Somehow the doorknob thing isn't working.
- 1:32:17I know I've taken us on this weird analogy path, so feel free to pivot.
- 1:32:21Yeah.
- 1:32:21No, no, no, no.
- 1:32:22Now we're stuck, baby.
- 1:32:23But let's go.
- 1:32:25So somehow the idea of this invariant thing that I want to recognize is no longer working.
- 1:32:31Yes.
- 1:32:31So...
- 1:32:32The failed autopsy is the following, right?
- 1:32:34Which is that this T cell that's getting activated to recognize the doorknob, it's insufficient.
- 1:32:41Because what it needs to do is it actually needs to prime the innate cells in the respiratory tissues.
- 1:32:49That seems to be the problem.
- 1:32:50That was the lesson that we learned.
- 1:32:52The infantry, not the special ops.
- 1:32:54Exactly.
- 1:32:54The special ops can know, but if the infantry doesn't, it doesn't matter.
- 1:32:56If the infantry don't know, then...
- 1:32:59It's too late by the time that the infection actually progresses.
- 1:33:02Fair, fair.
- 1:33:03Okay?
- 1:33:03And that's where we get into the paper that we have here.
- 1:33:06Okay.
- 1:33:07Out of Stanford.
- 1:33:08It's by the lab of Bali Pulendran.
- 1:33:11Okay.
- 1:33:13Integrated organ immunity.
- 1:33:15It's this idea that we need to shift from specific antigen matching to now target this T cell activation and fundamentally upgrade our system such that we can really think about a holistic approach about how the organ is actually...
- 1:33:33Doing this protection, okay?
- 1:33:36The protection requires continuous synergistic dialogue between your adaptive immune system, which is the special ops, and your structural cells that are in the tissue that are part of your innate system.
- 1:33:49immune system i'm so mad that this perfectly maps on to basically saying we need to build the cia intelligence agency for the human body to communicate intelligence yes uh we can't have sequestered information no stove pipes yes yes we can everyone needs to talk to everyone and share intelligence that's that's ultimately what's happening that's okay so now let's get into the paper right okay how does this vaccine actually work it's an intranasal vaccine
- 1:34:19So it's a spray that you put into your nose.
- 1:34:24The payload is the following.
- 1:34:25You've got ovalbumin.
- 1:34:26This is OVA.
- 1:34:27This is a model antigen that's encapsulated in...
- 1:34:31This is an antigen that actually just comes out of egg whites.
- 1:34:34Okay.
- 1:34:34Okay?
- 1:34:35So it has nothing to do with humans.
- 1:34:37It's kind of just there to prime the immune system.
- 1:34:40To be like, that's weird.
- 1:34:40I don't know what that is.
- 1:34:41Okay.
- 1:34:41Okay.
- 1:34:42Okay.
- 1:34:43And it's encapsulated inside a liposome, which is just like a little fat globule.
- 1:34:50And inside that liposome is a multifront threat.
- 1:34:54You've got GLA, which is something that mimics bacterial cell walls.
- 1:35:00So this is going to go after something like a toll-like receptor, TLR4-1.
- 1:35:05It triggers inflammation from antiviral and bacterial immune systems.
- 1:35:11And finally, it also has this 3M052LS, which is effectively like it's a molecule that targets other toll-like receptors.
- 1:35:20Toll-like receptors are like these things that are on, these are receptors that are on immune systems that detect viral DNA or like...
- 1:35:29other types of DNA and actually trigger immune response.
- 1:35:32It's like our radar systems or any of our, our, our, our signals, intelligence systems to, to figure out if someone shoots a hypersonic missile, we have all these satellites that will like know all the heat over here changed to a, such a degree that there's some, there's a threat over here.
- 1:35:49It's like identifying, listening to identify when there is a threatening coming.
- 1:35:54Yeah.
- 1:35:54Is that fair?
- 1:35:55Yes, exactly.
- 1:35:56And what's crucial about it is these two things, they're actually synthetic adjuvants.
- 1:36:02Okay.
- 1:36:02Adjuvants are little helpers that help the immune system but aren't actually the antigen that the immune system is trying to target.
- 1:36:11I see.
- 1:36:11It's sort of just priming the immune system to be on alert in some sense.
- 1:36:17Okay?
- 1:36:18Okay.
- 1:36:18Now, let's see if this actually works.
- 1:36:21And to be honest, even the lead author was like, I'm surprised that this works.
- 1:36:26Okay?
- 1:36:27Let's do the efficacy test.
- 1:36:29Okay.
- 1:36:30Turns out, four intranasal doses on vaccinated mice, and the mice were highly durable to SARS-CoV-2.
- 1:36:41This is COVID-19.
- 1:36:44Mouse-adapted SARS-CoV, which is the SARS virus.
- 1:36:49A coronavirus that was bat-derived, a gram-positive bacteria, and another gram-negative bacteria.
- 1:36:58So like five different things that had nothing to do with what I showed the immune system.
- 1:37:06That's what's key.
- 1:37:07Usually, for the COVID-19 vaccine to work, I need to show our immune system the spike protein from the COVID-19 virus.
- 1:37:15It's going to learn that spike protein, and then it's going to...
- 1:37:18Learn to recognize it.
- 1:37:18You have to show the keyhole of the lock that it needs to make keys for.
- 1:37:22Yeah.
- 1:37:22Specifically.
- 1:37:23Yeah.
- 1:37:23This is literally just priming the immune system to be like, watch out.
- 1:37:27And so, again, if I continue this annoying analogy, the primer is basically allowing the immune system to create several sets of keys before...
- 1:37:37Cats even show up.
- 1:37:39And it just so happens that because they created this preset of hundreds of thousands of keys.
- 1:37:44Yeah.
- 1:37:45They already, when it arrives, they can already be using those.
- 1:37:48Yeah, they already know, like, what is for it.
- 1:37:51Right.
- 1:37:52There's a signal of, like, okay, this is interesting.
- 1:37:55This is actually so good because...
- 1:37:59This goes back to what we've talked about before, which is to the extent that you, instead of inserting something artificial into the body to solve the problem, if you can just instigate the body to use its existing machinery to better solve the problem, that is always the better solution.
- 1:38:16Yes.
- 1:38:17That's exactly right.
- 1:38:19And now let's think about what is exactly happening.
- 1:38:22Right.
- 1:38:22Because you just introduced this very simple thing in the nasal...
- 1:38:28tract and now all of a sudden it's just like working doesn't make any sense to me it's just got a huge defense system out of nowhere yeah yeah so so how is it actually working so let's talk about the lungs right the respiratory tract is a really distinct immunological zone because it's kind of like the border between the outside and the inside for the human body right um
- 1:38:51There's a direct interface between the outside world and the inside world.
- 1:38:55So there's its own rules of engagement.
- 1:38:58That's fair.
- 1:38:58It's like this is not the blood, right, where the blood is shielded by the skin and the heart and the capillaries.
- 1:39:05The lung is like where the outside world is coming in and I need to get oxygen and release carbon dioxide, right?
- 1:39:11So there's a lot of stuff coming in.
- 1:39:13Yes.
- 1:39:14The rules of engagement are different.
- 1:39:17The battlefield is something like 480 million alveoli.
- 1:39:20Alveoli are these compartments inside the human lung that increase surface area such that there is a transfer of oxygen and carbon dioxide from the blood to the outside world.
- 1:39:32Okay?
- 1:39:33This is how oxygen gets into our blood.
- 1:39:35Yep.
- 1:39:39Every single lung has 70 square meters of surface area, which is roughly half a tennis court.
- 1:39:44So if you were to take our lungs and actually lay it out flat, that would be half a tennis court worth of surface area.
- 1:39:50That's really crazy, actually.
- 1:39:51That's actually.
- 1:39:51I didn't know that.
- 1:39:52Right?
- 1:39:53That's pretty cool.
- 1:39:54Now, the lung is naturally tolerogenic, meaning it tolerates a bunch of random stuff.
- 1:40:01It suppresses an immune response.
- 1:40:03If every time some random crap comes in and we have an immune response, that's not going to be good.
- 1:40:08It has an asylum program.
- 1:40:12Yeah.
- 1:40:13It's not a strict border where you can't cross.
- 1:40:16Yeah, because that would be completely unreasonable.
- 1:40:18Right.
- 1:40:18So it's like, okay, what's your case?
- 1:40:19Yeah.
- 1:40:21Exactly.
- 1:40:21Yeah.
- 1:40:22So now let's look at the cells, the immune cells that are responsible here.
- 1:40:27There's tissue resident immune cells, which are the tissue resident memory T cells.
- 1:40:32These are tissue resident, meaning they hang out.
- 1:40:35In the lung.
- 1:40:37Okay.
- 1:40:37Then there are these things called the alveolar macrophages.
- 1:40:42These are macrophages.
- 1:40:43So there's, these are innate immune cells.
- 1:40:45These are the beat cops, the infantrymen.
- 1:40:49They hang out in the alveoli.
- 1:40:51They were discovered by Eli Metzhinikov in the 1880s.
- 1:40:55He won the Nobel Prize in 1908 for it.
- 1:40:59They basically hang out in the alveoli, which are these compartments that interface between the blood and the outside world.
- 1:41:06I mean, it's literally the border.
- 1:41:08Yeah, they're the border cops in some sense, right?
- 1:41:11Yeah, yeah.
- 1:41:12And in the past, we used to believe that the memory T cells, which are our special ops.
- 1:41:17Yes, yes.
- 1:41:18they remain dormant until there's a specific target antigen that reappears.
- 1:41:23But the data from this particular paper shows that there's actually a radically different dynamic.
- 1:41:31When you put that nasal spray in, those tissue-resident memory T cells, they actually...
- 1:41:39broadcast training signals to these infantrymen.
- 1:41:44Interesting.
- 1:41:45These alveolar macrophages.
- 1:41:48So the special operations people actually have an active channel of communication that's...
- 1:41:54At the beginning of the inciting incident.
- 1:41:58Initially, the thought was the inciting incident happens.
- 1:42:00The infantrymen, the innate immune cells respond.
- 1:42:04There's no communication happening necessarily.
- 1:42:07But then because they're losing the battle, then we bring in the big guns.
- 1:42:11But actually what we're sort of seeing or saying here is –
- 1:42:15The special ops, the adaptive immune system.
- 1:42:17They get primed by that nasal spray.
- 1:42:20Right.
- 1:42:20And so now they, because they got primed by the nasal spray, they're already pre-sending information to the border where we have these innate immune cells to say, hey, be on alert.
- 1:42:33There might be a caravan coming through.
- 1:42:35Yeah.
- 1:42:36And because of that, it actually makes the effective response better.
- 1:42:40Yeah.
- 1:42:40Yeah.
- 1:42:44Let me wait.
- 1:42:45And so the question is, okay, how does that dialogue actually happen?
- 1:42:49That was my question.
- 1:42:51Right?
- 1:42:51Like, how are you talking to one another?
- 1:42:54Well, the dialogue happens from something called Rank L. They actually identified what this is.
- 1:42:58This is the receptor activator of nuclear factor kappa B ligand protein.
- 1:43:03Okay.
- 1:43:04Okay?
- 1:43:04This is a protein.
- 1:43:05These...
- 1:43:07T-cells broadcast high levels of this protein.
- 1:43:10Okay.
- 1:43:11And the crucial proof was if you were to block this pathway, you were to block this protein –
- 1:43:17This antibody The antibodies would completely vanish This response was completely Not there So when this was present This rank L when present The antibodies would generate and form And it's totally fine When it wasn't present You can artificially take it out Then there's basically a delayed or no response Yeah exactly
- 1:43:39And so what you're actually doing effectively is you're teaching these macrophages, these infantrymen, new tricks in some sense.
- 1:43:48So now the question becomes, well, how are you doing that?
- 1:43:50Yes.
- 1:43:51These macrophages, I thought, you know, they're kind of dumb, innate immunity.
- 1:43:55How are you training them to be immune and really select certain things and like become this more effective person?
- 1:44:05COP in some sense.
- 1:44:07Well, it turns out that they acquire biological memory not through genetic recombination, which is what we get from the special ops, but through epigenetic reprogramming.
- 1:44:18What's happening is you can imagine in epigenetics, right?
- 1:44:21Yeah.
- 1:44:23Your entire cellular genome is like a library.
- 1:44:26All of your DNA is like a library, but it's massive.
- 1:44:30And every single cell is specifically only reading certain books, right?
- 1:44:36Only certain parts of the genome are actually being expressed in certain cells.
- 1:44:41Now, a vast majority of these books are tightly shut.
- 1:44:46through epigenetic markers.
- 1:44:48And what ends up happening is there are proteins called histones that wrap around segments of DNA that they don't want the cell to look at.
- 1:44:58What's happening with these particular macrophages is that level of...
- 1:45:05Books being shut and open is being changed.
- 1:45:09There's two types of chromatin.
- 1:45:11There's heterochromatin and euchromatin.
- 1:45:14Chromatin is like our DNA.
- 1:45:16Heterochromatin is all of our DNA that's being packaged up so that no one can read it.
- 1:45:20Euchromatin is kind of the histones are...
- 1:45:24Spread out.
- 1:45:25And you can actually read the DNA and make proteins out of that DNA.
- 1:45:29It's like an encrypted versus a non-encrypted messaging channel.
- 1:45:32That's exactly right.
- 1:45:33And what they could see is that the rank L signaling...
- 1:45:37was unspooling the DNA and making parts of the DNA more visible.
- 1:45:43It was left out in the open.
- 1:45:45In the context of a heterochromatin becoming more like a... More euchromatin.
- 1:45:50Exactly.
- 1:45:51And very specific parts of that DNA were becoming more accessible.
- 1:45:55Meaning certain books in the libraries, which had good things in those specific books.
- 1:46:01Yes.
- 1:46:01Like how to identify stuff.
- 1:46:04How to be a better cop.
- 1:46:05That's actually fascinating.
- 1:46:07Yeah.
- 1:46:08Oh, man, that's really good.
- 1:46:09Yeah.
- 1:46:10Because you can sort of imagine, like, it kind of makes sense where it's like you don't, too much information is going to overload any system.
- 1:46:20And so you have to be selective about what information is displayed to what party when.
- 1:46:26And that coordination problem at the level of the body.
- 1:46:29is orders of magnitude.
- 1:46:31Because of the number of constituent parts and combinatorial processes that stack on top of each other, it makes my head hurt.
- 1:46:41Yeah.
- 1:46:41Yeah, there's too much, right?
- 1:46:44And it's just pretty cool that we could get down to this level of chromatin remodeling to understand it.
- 1:46:52Isn't epigenetics still something as a concept that is in its infancy...
- 1:46:58Very much so, compared to like DNA, for example.
- 1:47:01Yeah.
- 1:47:02So I think the reason it's fascinating to me is, you know, we're continuing to chip away at the understanding.
- 1:47:10And it's funny how...
- 1:47:14epigenetics plays an increasingly more important role as we get deeper into the understanding of these systems.
- 1:47:21Exactly, yeah.
- 1:47:22And one more thing that I want to touch on with this paper is they ask the question, well, where are these cells interacting?
- 1:47:29I think you're going to like this one because there's a cool mechanism about how they actually did the science and then what they actually found out.
- 1:47:37Okay.
- 1:47:37Okay?
- 1:47:38So the question is, where are these immune responses actually happening?
- 1:47:42Okay.
- 1:47:43Okay?
- 1:47:44So usually when you want to answer that question, what you do is you take a bunch of lung tissue, you put it into a blender, and then you run some transcriptomics, and you try to figure out what part of the genome is being read.
- 1:47:57When you say a blender...
- 1:47:58A literal, yeah.
- 1:47:59Okay.
- 1:48:00Just checking.
- 1:48:00Yeah, you just mix it up.
- 1:48:02Okay.
- 1:48:02Then you put some transcriptomic stuff in it, which tells you, like, what part, like, what is the mRNA profile.
- 1:48:08Got it.
- 1:48:09Right?
- 1:48:09But because it's in a blender now, you don't have any of spatial...
- 1:48:12Yes.
- 1:48:12You've lost all of the spatial information.
- 1:48:14Yes.
- 1:48:14Right?
- 1:48:15What we'd want to do...
- 1:48:17is try to figure out where the genes are being transcribed.
- 1:48:22Like in a tissue, I take a slice of lung, let's say, from my mouse, and I want to figure out where is the immune response happening geographically.
- 1:48:31Yes.
- 1:48:32Okay.
- 1:48:32Yes.
- 1:48:33So they used a technique called phenocytor fusion.
- 1:48:37It used to be formally called Codex for spatial proteomics.
- 1:48:42Here's the idea.
- 1:48:43Okay.
- 1:48:43So normally what you do,
- 1:48:45is you want to figure out where the proteins are, right?
- 1:48:47Where specific proteins are.
- 1:48:49So you make an antibody that is tailored to stick to that particular protein.
- 1:48:54It sticks to that particular protein.
- 1:48:56Each of these antibodies has a fluorescent dye on it, so it's going to glow in the dark in some sense.
- 1:49:02So if we look at the...
- 1:49:04Photo we have here, each of these antibodies is tagged with a fluorescent dye.
- 1:49:09Each of the different colors tells us what different antibody there is.
- 1:49:14And there you go.
- 1:49:14You've got a geographic map of where the stuff is.
- 1:49:19Now, you're limited to mostly like four or five different colors, though.
- 1:49:23Okay.
- 1:49:23Right?
- 1:49:23Because you don't have that many dyes.
- 1:49:25You don't have that many lasers.
- 1:49:27Yeah, yeah, yeah.
- 1:49:28So what if we want to do like hundreds of different types of proteins?
- 1:49:33How am I going to actually do this?
- 1:49:34Well, with codex, with this phenocytolar fusion, here's what we're doing.
- 1:49:41The antibody is actually not attached to a dye.
- 1:49:45It's attached to a piece of DNA.
- 1:49:47Okay.
- 1:49:47Okay?
- 1:49:48Each different type of antibody is attached to a piece of DNA.
- 1:49:52Then we have another piece of DNA that...
- 1:49:55that is complementary, that is attached to a die.
- 1:49:59And so now you have a barcode, and you have another barcode.
- 1:50:05Do you already see it?
- 1:50:07It's so nice.
- 1:50:08Okay, so here's what we're doing.
- 1:50:10Here's what we're going to do.
- 1:50:12This is good.
- 1:50:12Right?
- 1:50:13The antibody is attached to a DNA.
- 1:50:15I have another piece of DNA that latches onto that DNA.
- 1:50:17It's complementary.
- 1:50:18Just the A becomes a T, C becomes a G. That attaches, and that has a bit of dye.
- 1:50:25Okay?
- 1:50:26So when I'm, like, looking at a Where's Waldo type book, right, and let's say I want to find all the people with red hats, Mm-hmm.
- 1:50:35I have a little thing that says attach to the red hats and then I take a picture.
- 1:50:41Then I wash it out.
- 1:50:43And this is the next photo I think you'll see.
- 1:50:45Yes.
- 1:50:46This is the cycle.
- 1:50:47I attach.
- 1:50:49I take a photo.
- 1:50:50I wash it out.
- 1:50:51I attach with another barcode.
- 1:50:53I take a photo.
- 1:50:54The key is I can take a photo with the same color of light.
- 1:50:58But...
- 1:51:00Because the primer is being attached at different locations, I now have a snapshot at every given point.
- 1:51:07Yes, yes.
- 1:51:08And so I can expand the number of proteins that I can actually image.
- 1:51:12Right.
- 1:51:13Because you're no longer limited by the number of dyes and lasers you have.
- 1:51:18Yeah.
- 1:51:19Because the mechanism to make the connection is now this one part of DNA connected to the other part of DNA.
- 1:51:24On the other side of it, it can have a whole range of stuff
- 1:51:28That's very It's such a nice idea It's only in the last five years This was also developed at Stanford This is a very clever technique I have to say That's quite nice It feels non-obvious As a choice But then once you think about it You're like oh That's why I literally For those who are listening and not watching me After you almost got through the second or third sentence I almost fell out of my chair Because I immediately understood
- 1:51:58Come on, it's so obvious.
- 1:52:01It's so nice.
- 1:52:02But it always takes one.
- 1:52:03Yeah, and so here's what they found with that.
- 1:52:05Okay.
- 1:52:06What they actually found when they looked at these lungs...
- 1:52:09They found, with spatial imaging, tertiary lymphoid structures.
- 1:52:14Here's the idea.
- 1:52:15Usually, when it comes to this adaptive immune response, the antigen has to go to a lymph node.
- 1:52:23It's got to get integrated there.
- 1:52:24The T cells has to recognize, and then it's got to come back.
- 1:52:27This is going to take weeks.
- 1:52:28Okay?
- 1:52:30What they see in the lungs of these mice...
- 1:52:33is that the immune cells are rapidly congregating and building up pop-up makeshift lymph nodes.
- 1:52:41Like on the battlefield, they're doing management and creating like little, I don't know.
- 1:52:47You know what I mean?
- 1:52:48Yeah, yeah, yeah.
- 1:52:49They have these outposts at specific areas on the battlefield.
- 1:52:53On the battlefield, in the lungs themselves.
- 1:52:55That are relevant.
- 1:52:56So you don't have to go all the way back to the lymph nodes to figure out.
- 1:53:01So in this analogy, if you have a central command that houses the core intelligence pieces, what's happening is we're actually getting these satellite outposts that have –
- 1:53:14localized intelligence and relevant information so that people who are nearby don't need to wait because they already have basically preloaded, not preloaded, but they already have the relevant information that those that are nearby are able to access without waiting for the signal to come back from Central Command.
- 1:53:32Yeah.
- 1:53:33tertiary, what was it?
- 1:53:34Tertiary lymphoid structures.
- 1:53:36Yeah, lymphoid is, the lymph nodes are like organ systems that coordinate the immune response.
- 1:53:42Man, that's crazy.
- 1:53:43And here, that organ system is now creating little tiny outposts.
- 1:53:47Yeah, yeah, yeah.
- 1:53:49Yeah, all crazy.
- 1:53:50Which, again, if we look at just like military tactics as a reference point.
- 1:53:54It's like so...
- 1:53:55It like maps on.
- 1:53:56It maps on almost perfectly.
- 1:53:57Yeah, it's kind of crazy.
- 1:53:59It's kind of crazy.
- 1:54:00Yeah, it is kind of crazy.
- 1:54:02It is kind of crazy.
- 1:54:04The one that I got really...
- 1:54:06kind of excited about was the idea that it could actually like help allergies and allergy asthma because um it turns out that allergies are basically a maladaptive response to harmless allergens right it's like the immune system just kind of going ah what's going on what is going on right but um this particular vaccine it's designed to aggressively bias the immune system towards antiviral sort of
- 1:54:32innate immune response rather than like, oh, I recognize something that's bad.
- 1:54:37And the vaccinated mice...
- 1:54:40So on the left, you see naive mice that are control.
- 1:54:43In the middle, you see unvaccinated mice that are part of this HDM challenge, which is effectively you're introducing like an allergen to them.
- 1:54:51You see lots of mucus buildup, right, in the middle.
- 1:54:54On the right-hand side, it looks more like control.
- 1:54:56It looks like I don't got a stuffy nose.
- 1:54:59Yes, that's exactly right.
- 1:55:00So it's actually like...
- 1:55:03It's sort of calibrating that allergy response as well.
- 1:55:06I mean, I think this is huge, right?
- 1:55:08Because it's, first of all, it's a completely different way of trying to understand how vaccines work.
- 1:55:14Right.
- 1:55:14And how to implement vaccines.
- 1:55:16Right.
- 1:55:16Right?
- 1:55:17It's no longer a lock and key mechanism.
- 1:55:19It's literally just saying we're just going to prime the immune system.
- 1:55:21Mm-hmm.
- 1:55:22to be on high alert.
- 1:55:25And for something like a pandemic that's happening in the future, it's going to happen in the future.
- 1:55:29Yes.
- 1:55:30Right?
- 1:55:32There's a pandemic coming.
- 1:55:35This can be kind of a stopgap because imagine there's a pandemic that comes out of wherever.
- 1:55:42You can fly out these vaccines that don't need vaccines.
- 1:55:47a sequence of whatever pathogen there is.
- 1:55:50I don't need to know what COVID-19 is or what COVID, I don't know, 2027 is.
- 1:55:57I can just fly out these vaccines, and whatever healthcare worker is going in there or whatever, their immune system is going to be primed for whatever random crap is coming their way.
- 1:56:08Yes.
- 1:56:09This is – it generalizes –
- 1:56:12vaccines in a way where you can have inventory and stockpile of this generic... Again, this is an early story.
- 1:56:24Very early.
- 1:56:25Caveat, caveat, caveat.
- 1:56:27I'm going to get into the caveats later, but I still think it's... Because it...
- 1:56:32Clearly, there's mechanisms that mean that this makes sense.
- 1:56:35Yes, yes, exactly.
- 1:56:36That's the big thing, right?
- 1:56:38Clearly, it worked in mice, which means that we're just mammals.
- 1:56:41Like, maybe this might not work.
- 1:56:43Right.
- 1:56:43But it's a paradigm shift, I think, in how we think about...
- 1:56:48Vaccines in general.
- 1:56:49Yes.
- 1:56:50And the idea of priming our immune system.
- 1:56:52Yes.
- 1:56:53In an early way.
- 1:56:54I mean, it makes total sense.
- 1:56:55Like if, I mean, this is maybe a bad, a bad, like if you're, if you're going to do, if your body is about to go through trauma.
- 1:57:04Yeah.
- 1:57:05Like, let's say you're going to run a marathon.
- 1:57:06Yeah.
- 1:57:07You're going to want to train before the marathon.
- 1:57:09And this is sort of a means by which for us to arbitrarily activate the immune system, because it has the capability, back to what we said before, it has the capability to deal with the problem.
- 1:57:23But it doesn't necessarily have enough of a running start to deal with that time gap problem we talked about earlier.
- 1:57:30Yeah.
- 1:57:31And if we just give it an extra little bit of a head start, its natural response will be better at taking care of the situation.
- 1:57:38Exactly, yeah.
- 1:57:39And I mean, there's caveats, right?
- 1:57:41I think the researchers, when they go into human trials, they need to make sure that it doesn't cause these things called cytokine storms, which is this auto-inflammation.
- 1:57:51where the immune system just attacks the body itself, right?
- 1:57:56Gets confused.
- 1:57:57I can imagine there are some problems here, right?
- 1:58:00Where you're like, you've basically just put the immune system in your lung on high alert.
- 1:58:06I mean, one would make the analogy that if you have a nation with a border, and then you create an overzealous...
- 1:58:15like police force to respond to that.
- 1:58:18Right.
- 1:58:18You might start ending up shooting people inside the border.
- 1:58:23Right, right.
- 1:58:23When you're focused on people who are coming from outside the border.
- 1:58:27Yes.
- 1:58:27So as an analogy.
- 1:58:28As an analogy, of course.
- 1:58:30We do not want to have an overzealous situation.
- 1:58:34immune system because we don't want to start shooting our own people.
- 1:58:36Yes, because that would be... Everyone agrees that's bad, right?
- 1:58:39We don't want our body to die.
- 1:58:40We don't want our own cells to get affected.
- 1:58:44We want to...
- 1:58:46Get the threat.
- 1:58:47Yes.
- 1:58:47Yeah.
- 1:58:48So that's something that's an issue, right?
- 1:58:50Yeah, totally.
- 1:58:51Cytokine storms, also known as... Nice.
- 1:58:57We're not going to put this on Instagram because apparently...
- 1:58:59Apparently people got very upset about a joke.
- 1:59:02Anyways, but that's one of the...
- 1:59:06You know, caveats of these.
- 1:59:07That makes sense.
- 1:59:08Like, the immune system is notoriously finicky.
- 1:59:11Right.
- 1:59:12So we don't know.
- 1:59:13But at the end of the day, I think it's a lot of very cool fundamental research that's happening.
- 1:59:18I think it'll be very, very interesting to see where this leads.
- 1:59:22You said that I was going to like the vaccine story.
- 1:59:26I think it's very cool.
- 1:59:27I tend to, and apologies for those who sometimes feel like we're getting a little too deep.
- 1:59:32I tend to like the stories that have a really keen fundamental insight about something that was non-obvious.
- 1:59:41And required a little bit of creativity or outside of the box thinking to problem solve from an experimental design and solution perspective.
- 1:59:49So that one was quite nice.
- 1:59:50Yeah.
- 1:59:51That one was quite nice.
- 1:59:52We started off really far away.
- 1:59:56And then we ended up really, really close to home.
- 1:59:58Really close to home.
- 2:00:00Our first story was our astrobiology story out of PNAS Nexus, Johns Hopkins University.
- 2:00:08This was on our idea of understanding panspermia and the three aspects that are necessary in order for something to an organism that's life on one rock to make it to another rock.
- 2:00:23One and a half of those threes was already kind of solved, but this was a new one that's now solved, which is the initial departure from the rock.
- 2:00:31Getting off the planet, yeah.
- 2:00:33On high impact.
- 2:00:34We ended with this immunology story about the one vaccine to rule them all in a different approach.
- 2:00:39Instead of going after a pathogen specifically, can we prime the pump?
- 2:00:45in the immune system to just have a better, more generalized response with some interesting dynamics of understanding how adaptive and innate immune cells communicate with each other.
- 2:00:54Yeah.
- 2:00:55On the battlefield, several good rundown stories.
- 2:00:59If you've made it to the end,
- 2:01:01You are very special because you get to get a prompt for a comment of the day.
- 2:01:07I want to call out.
- 2:01:08I'm going to pull this up real time here because I didn't do so earlier.
- 2:01:12I want to call out one of the previous comments from last week's episode, which I think there were two that were quite interesting.
- 2:01:20that were one at least was quite good.
- 2:01:22The second one might be okay.
- 2:01:24And I think this one came right before we started recording.
- 2:01:28And so please bear with me.
- 2:01:30Okay.
- 2:01:31Yes.
- 2:01:32So two days ago, this was for our last episode.
- 2:01:34We asked for come up with a better acronym for GPLD1.
- 2:01:40Yeah.
- 2:01:41And so one of them was garlic pepper lemon dip.
- 2:01:43Yeah.
- 2:01:44Um, because apparently we made someone hungry.
- 2:01:47Um, so garlic pepper lemon dip sounds actually quite nice.
- 2:01:51And then we had another one earlier today, which I guess may have been on YouTube because I'm not seeing it here.
- 2:01:58And so this is now bad and a bad plug and I don't have it pulled up.
- 2:02:02Let me pull up YouTube really quick.
- 2:02:03If you listen this long, you're in it for the long haul.
- 2:02:06Yeah, you're in it.
- 2:02:06Just keep listening.
- 2:02:08Whatever.
- 2:02:08Give us a second here.
- 2:02:10This is bad pre-production prep by me.
- 2:02:12But I want to make sure people get their just desserts here on some of these really clever references.
- 2:02:20And nope, I don't see the one.
- 2:02:22All right.
- 2:02:23So I failed on it.
- 2:02:24But what should we have for the comment this time?
- 2:02:28This was a good one.
- 2:02:29Penspermia.
- 2:02:31Yeah, a different definition for panspermia.
- 2:02:34That's exactly what I was thinking.
- 2:02:36Yeah.
- 2:02:36I like that one.
- 2:02:36What do you guys think?
- 2:02:37I like that one.
- 2:02:38Panspermia.
- 2:02:38Give me another definition.
- 2:02:40I like that one.
- 2:02:41That is quite good.
- 2:02:43I'm your host.
- 2:02:44Keep it PG.
- 2:02:45Yeah, please.
- 2:02:46Please.
- 2:02:4613.
- 2:02:47PG-13.
- 2:02:4713.
- 2:02:48Kids can go to PG-13.
- 2:02:49It's not that bad.
- 2:02:50Yeah, it's not that bad.
- 2:02:51Um...
- 2:02:53I am your host, Lester Nare, joined as always by my co-host and our resident PhD, Krishna Chowdhury.
- 2:03:01I'll make one last reference.
- 2:03:02He's wearing a SpongeBob t-shirt today.
- 2:03:04I don't know if you've heard of this music artist called Glorb, G-L-O-R-B.
- 2:03:11So he took AI to voice all of the characters in SpongeBob and then dropped some of the craziest rap beef tracks like two or three years ago where it's like SpongeBob and Patrick and Sandy and Mr. Krabs and Plankton voices are rapping on trap beats.
- 2:03:30And I'm not going to lie, I was actually listening to some of his tracks earlier today on the way home.
- 2:03:35You need to send me some.
- 2:03:38I learned English on Spongebob.
- 2:03:41This music is not PG-13.
- 2:03:44So parents do not.
- 2:03:46It's not PG-13.
- 2:03:48But the voice duplication is incredible.
- 2:03:53And there's like a beef between the chum bucket and the crusty crab.
- 2:03:56Okay.
- 2:03:58This is no longer about science, so we will sign off here.
- 2:04:01We will see you all next week.
- 2:04:03This is From First Principles.