Latest / Daniel and Kelly’s Extraordinary Universe / Listener Questions 69

Transcript

Listener Questions 69 · Daniel and Kelly’s Extraordinary Universe

• 0:08
  Speaker 1: Hey, Daniel, would you rather live in the Star Wars
• 0:11
  Speaker 1: or Star Trek universe?
• 0:14
  Speaker 2: Oh? Man, I'm not sure.
• 0:16
  Speaker 3: I guess I'd prefer to live in the one that's
• 0:18
  Speaker 3: more scientific, you know, that follows actual laws.
• 0:22
  Speaker 1: I think they use more particle names in Star Trek.
• 0:26
  Speaker 1: They might be made up. I know in Star Wars
• 0:29
  Speaker 1: they use Midi Chlorians, which are definitely not made up.
• 0:33
  Speaker 3: Yeah, but I think Star Wars leans on the little
• 0:36
  Speaker 3: magic aspect a bit too much. I think Star Trek
• 0:38
  Speaker 3: is trying to sound more scientific at least.
• 0:41
  Speaker 1: I mean, isn't that basically our jobs, right? We're always
• 0:46
  Speaker 1: trying to sound more scientific.
• 0:49
  Speaker 3: I mean I do my best to sound like a
• 0:51
  Speaker 3: physics professor. I hope it's working.
• 0:53
  Speaker 1: I yeah, I think you had me fooled there for.
• 0:56
  Speaker 2: A minute, you and all the listeners.
• 0:58
  Speaker 1: I hope the big reveal.
• 1:17
  Speaker 3: Hi, I'm Daniel, I'm a particle physicist and a professor
• 1:19
  Speaker 3: at UC Irvine.
• 1:20
  Speaker 2: Really really, I promise I am.
• 1:23
  Speaker 1: I'm Katie Golden. I'm none of those things, but you know,
• 1:26
  Speaker 1: I do have an animal biology podcast, and I'm interested
• 1:30
  Speaker 1: in physics, or.
• 1:32
  Speaker 2: At least you can make it sound like you are.
• 1:35
  Speaker 1: That's so interesting, Daniel.
• 1:38
  Speaker 3: And Welcome to the podcast Daniel and Jorge Explain the Universe,
• 1:42
  Speaker 3: a production of iHeartRadio in which we sound interested in
• 1:46
  Speaker 3: the big questions of the universe, because we really really
• 1:49
  Speaker 3: are interested. We want to know how everything works, where
• 1:52
  Speaker 3: it all came from, how it all comes together to
• 1:55
  Speaker 3: create our amazing, glittering, beautiful, mysterious cosmos, and we want
• 2:00
  Speaker 3: to make sure that everybody out there understands things as
• 2:03
  Speaker 3: well as we do and as well as we don't.
• 2:06
  Speaker 3: Thanks very much Katie for joining me on today's episode.
• 2:09
  Speaker 1: I'm super excited. I love to hear people's questions because
• 2:14
  Speaker 1: usually they are something that I am also curious about,
• 2:17
  Speaker 1: and I also don't know the answer to.
• 2:20
  Speaker 2: That's right.
• 2:21
  Speaker 3: Many of our episodes are us explaining a concept in
• 2:24
  Speaker 3: physics to you, but we don't want this podcast to
• 2:27
  Speaker 3: be a one directional lecture. We want it to be
• 2:29
  Speaker 3: a conversation. We want to know what you are wondering
• 2:33
  Speaker 3: about when those ideas don't click in your mind. We
• 2:35
  Speaker 3: want to hear from you so we can help you understand.
• 2:39
  Speaker 3: So please, if you have questions, right to me to
• 2:41
  Speaker 3: questions at Danielandjorge dot com. Everybody gets an answer from
• 2:45
  Speaker 3: a real live physics professor.
• 2:46
  Speaker 2: They really really do.
• 2:48
  Speaker 3: And sometimes I hear a question from listeners, I think, well,
• 2:51
  Speaker 3: I bet a lot of people ask this question, or
• 2:54
  Speaker 3: a lot of people would appreciate the answer, or that
• 2:56
  Speaker 3: one would be fun to joke with Katie about. So
• 2:59
  Speaker 3: let's do it on the podcast.
• 3:01
  Speaker 1: No physicists were harmed in the making of this Listener
• 3:04
  Speaker 1: Questions episode.
• 3:06
  Speaker 2: Not yet, but I'll keep you up to date. We'll
• 3:08
  Speaker 2: see if that changes.
• 3:11
  Speaker 3: And so today on the podcast, we'll be answering Listener Questions,
• 3:19
  Speaker 3: Episode number sixty nine.
• 3:22
  Speaker 1: There's nothing funny about that number.
• 3:25
  Speaker 3: Absolutely nothing. We have been counting down to Listener Question
• 3:28
  Speaker 3: sixty nine ever since we've been doing Listener Questions and
• 3:31
  Speaker 3: we realized we were going to get there.
• 3:33
  Speaker 1: I get it. The six looks like a nine upside down.
• 3:36
  Speaker 1: That's what's funny about it.
• 3:39
  Speaker 3: Yeah, that's exactly what's funny about it. It reminds me a
• 3:41
  Speaker 3: little bit of when comic Shoemaker Levy hit Jupiter. When
• 3:45
  Speaker 3: it ran around the sun. The comment broke up into
• 3:47
  Speaker 3: like twenty six pieces. So somebody in NASA was like, ooh,
• 3:51
  Speaker 3: let's give the comet pieces names and we'll use letters
• 3:54
  Speaker 3: because there's twenty six of them. So there was the
• 3:56
  Speaker 3: A fragment, the B fragment, the C fragment, and then
• 3:59
  Speaker 3: when the first piece hit Jupiter, they called it the
• 4:02
  Speaker 3: A spot, and the next one when they hit they
• 4:05
  Speaker 3: called it the B spot. And then when they got
• 4:07
  Speaker 3: up to the F spot, they realized, uh oh, they
• 4:09
  Speaker 3: had a problem with the next one because were they
• 4:11
  Speaker 3: really going to write a scientific paper about Jupiter's G spot.
• 4:15
  Speaker 1: I have no idea what you're talking about. That just
• 4:18
  Speaker 1: sounds like numbers and words to me.
• 4:22
  Speaker 3: So they ended up talking about the F spot and
• 4:24
  Speaker 3: then the G impact site, and then the H spot.
• 4:27
  Speaker 1: Somehow that sounds dirtier to me. I don't know impact
• 4:30
  Speaker 1: site all right.
• 4:32
  Speaker 3: Anyway, we've got to do our best to extract humor
• 4:35
  Speaker 3: from science. But on today's episode, we are not just
• 4:37
  Speaker 3: making jokes about the number sixty nine. We were answering
• 4:39
  Speaker 3: questions from listeners like you, and today's episode is discussion
• 4:43
  Speaker 3: of a question from Dale from Washington. Here is Dale's question.
• 4:49
  Speaker 4: Hello, Daniel and Jorge, This is Dale from Chattarroy, Washington.
• 4:52
  Speaker 4: I was watching Star Trek the other day and it
• 4:55
  Speaker 4: occurred to me that when the Enterprise D is cruising
• 4:59
  Speaker 4: a speed of warp six and the stars were all
• 5:02
  Speaker 4: speeding by, they maybe shouldn't have been able to see
• 5:05
  Speaker 4: them due to blue shift. Would the light be shifted
• 5:10
  Speaker 4: all the way into ultraviolet or maybe even X rays
• 5:14
  Speaker 4: or even further down? Is that even possible at a
• 5:18
  Speaker 4: large percentage of the speed of light? Anyways, thanks for
• 5:22
  Speaker 4: listening to my question.
• 5:24
  Speaker 3: All right, Katie, are you a Star Trek fan? Have
• 5:26
  Speaker 3: you wondered about this yourself?
• 5:27
  Speaker 1: So? I have watched a good amount of Star Trek,
• 5:31
  Speaker 1: and I I'm always kind of I don't know. I
• 5:34
  Speaker 1: guess I kind of gloss over the weird engineering babble.
• 5:38
  Speaker 1: It doesn't it's like we got to put the transoperitors
• 5:42
  Speaker 1: or interopertors on the warp schism. I don't really know.
• 5:48
  Speaker 1: And like I'm also a little bit confused about the
• 5:51
  Speaker 1: concept of the warp drive. I know there are different
• 5:54
  Speaker 1: like warp speeds, but like the idea, I guess is
• 5:58
  Speaker 1: that what you're like ending space and making the ship
• 6:03
  Speaker 1: go across. I don't know. Do you know if they
• 6:05
  Speaker 1: ever did like an explanation of warp drive.
• 6:09
  Speaker 3: Well, one of the funny things about Star Trek is
• 6:11
  Speaker 3: that it's not really science fiction. I mean, they don't
• 6:15
  Speaker 3: actually have any sort of explanation for what they're doing.
• 6:18
  Speaker 3: It's exactly as you described. It's like particle babble.
• 6:21
  Speaker 2: It's sort of like.
• 6:22
  Speaker 3: The way jen Ai is. You know, you ask chat
• 6:25
  Speaker 3: gbt to generate an answer to physics question and it'll
• 6:28
  Speaker 3: generate a bunch of words which sound like an answer,
• 6:31
  Speaker 3: and Star Trek is kind of like that. It's like,
• 6:33
  Speaker 3: here's a convincing number of words which sort of sound
• 6:35
  Speaker 3: like an explanation for the science, but it's really nonsense,
• 6:39
  Speaker 3: you know. And I gotta love that about Star Trek.
• 6:42
  Speaker 3: They're not really trying to be hard sci fi. They
• 6:44
  Speaker 3: sort of make fun of themselves a little bit. They
• 6:46
  Speaker 3: don't take themselves too seriously. The science of Star Trek
• 6:49
  Speaker 3: is not like crisply thought out and click together into
• 6:51
  Speaker 3: some coherent explanation, as you'll see when we dig into
• 6:55
  Speaker 3: what a warp drive is in Star Trek and what
• 6:58
  Speaker 3: it should look like when you look out right.
• 7:01
  Speaker 1: But the idea being that you're going really really fast,
• 7:05
  Speaker 1: like is the idea that you're going at the speed
• 7:07
  Speaker 1: of light.
• 7:09
  Speaker 3: The idea of a warp drive in physics aside from
• 7:12
  Speaker 3: star trek is an attempt to move faster than the
• 7:15
  Speaker 3: speed of light. So we have this frustrating limitation on
• 7:18
  Speaker 3: all motion in the universe that nothing can move faster
• 7:21
  Speaker 3: than the speed of light through space. So if you
• 7:23
  Speaker 3: want to fly to Alpha Centari and it's three light
• 7:25
  Speaker 3: years away, it's going to take you at least three
• 7:28
  Speaker 3: years to get there because you can't even go at
• 7:31
  Speaker 3: the speed of light. Nothing with mass can move even
• 7:34
  Speaker 3: at the speed of light, and nothing at all can
• 7:35
  Speaker 3: move faster than the speed of light. And the speed
• 7:38
  Speaker 3: of light is really really fast, you know, one hundred
• 7:40
  Speaker 3: and eighty six thousand miles per second is incredibly fast,
• 7:43
  Speaker 3: But distances in space are incredibly vast, and so stars
• 7:48
  Speaker 3: are far apart even compared to the speed of light.
• 7:51
  Speaker 3: So our galaxy, for example, is one hundred thousand light
• 7:54
  Speaker 3: years across. You wanted to go from here to the
• 7:56
  Speaker 3: other side of it and back, we're talking two hundred
• 7:59
  Speaker 3: thousand years even if you're a photon. So it's incredibly
• 8:03
  Speaker 3: hard to get around the universe because the speed of
• 8:06
  Speaker 3: light is actually very very slow. And in science fiction
• 8:10
  Speaker 3: universes people often want to have like galaxy spanning empires
• 8:13
  Speaker 3: or civilizations that go from star to star, and it's
• 8:16
  Speaker 3: kind of hard to make that work unless you have
• 8:19
  Speaker 3: faster than light travel. So a warp drive in physics
• 8:22
  Speaker 3: is a way to try to circumvent use loopholes in
• 8:25
  Speaker 3: special relativity to make it possible to go from here
• 8:28
  Speaker 3: to there in less time than a photon would take.
• 8:32
  Speaker 1: Okay, so it's some kind of magic.
• 8:37
  Speaker 3: Well, there really is a concept in physics of a
• 8:40
  Speaker 3: warp drive, and it doesn't break special relativity. The law
• 8:43
  Speaker 3: in special relativity says you can't move through space faster
• 8:46
  Speaker 3: than light does. But a warp drive doesn't move through space.
• 8:50
  Speaker 3: It actually compresses space. Because what we've learned in the
• 8:53
  Speaker 3: last one hundred years or so is that space is
• 8:55
  Speaker 3: not just like an empty backdrop on which the things
• 8:58
  Speaker 3: in the universe happen. It's actually like a thing. It
• 9:01
  Speaker 3: has features, It can bend and curve and ripple and expand.
• 9:06
  Speaker 3: And so if, for example, you could compress the space
• 9:08
  Speaker 3: between here and a distant star so that it's not
• 9:11
  Speaker 3: actually as far, then you could just move a lower
• 9:14
  Speaker 3: than the speed of light but still get there very
• 9:17
  Speaker 3: very quickly. That's the basic idea of a warp drive,
• 9:20
  Speaker 3: and people want to know more about the physics of
• 9:22
  Speaker 3: a warp drive and is it possible. Can check out
• 9:24
  Speaker 3: some of the episodes that we have about warp drives.
• 9:27
  Speaker 3: But that's actually a possibility. We don't know how to
• 9:29
  Speaker 3: make it work. We don't have to build one, but
• 9:32
  Speaker 3: the laws of general relativity say it might be possible.
• 9:35
  Speaker 3: And we're talking about in our real universe. In Star Trek,
• 9:38
  Speaker 3: their warp drive is a little bit different.
• 9:40
  Speaker 1: Okay, so how does the Star Trek warp drive quote
• 9:44
  Speaker 1: unquote work.
• 9:46
  Speaker 3: So the basic principle is the same, is that you're
• 9:48
  Speaker 3: going faster than the speed of light. And they have
• 9:50
  Speaker 3: these warped levels, so like warp one, warp two, warp three,
• 9:54
  Speaker 3: each of those goes faster and faster, and for example,
• 9:57
  Speaker 3: and warp nine point nine is the maximum that they
• 9:59
  Speaker 3: could have do. And if they ever go warp nine
• 10:01
  Speaker 3: point nine, you can really see it straining their ship.
• 10:07
  Speaker 1: That seems like airplane or boat logic right where it's
• 10:10
  Speaker 1: still the idea that you are like moving in a
• 10:12
  Speaker 1: way where there is some kind of like resistance against
• 10:17
  Speaker 1: your ship, and then if you're going faster, there's more
• 10:20
  Speaker 1: strain on the ship. But if this is about scrunching
• 10:24
  Speaker 1: space time. It doesn't seem like that would have the
• 10:27
  Speaker 1: same kind of effects as say, like a jet plane
• 10:30
  Speaker 1: trying to a sound barrier.
• 10:33
  Speaker 3: Yeah, exactly, But the warp drive on Star Trek isn't
• 10:36
  Speaker 3: a general relativistic squeezing space creating a warp bubble kind
• 10:40
  Speaker 3: of situation. They don't explain at all how it works.
• 10:43
  Speaker 3: It's just sort of like, we can go faster than
• 10:44
  Speaker 3: the speed of light.
• 10:45
  Speaker 2: We have a warp drive.
• 10:46
  Speaker 1: Right, Okay, so part of the question was about blue ships.
• 10:51
  Speaker 1: So the idea is like, so, okay, you have one
• 10:54
  Speaker 1: of these warp drives where you can go faster than
• 10:57
  Speaker 1: the speed of light, and there is the obvious question
• 11:02
  Speaker 1: of what would like look like to you? But can
• 11:04
  Speaker 1: you explain what the question asker means when they talk
• 11:07
  Speaker 1: about blueshift?
• 11:09
  Speaker 3: Yeah, I think basically he's wondering, what does it look
• 11:12
  Speaker 3: like out the window when you are doing the warp drive?
• 11:15
  Speaker 2: Right?
• 11:15
  Speaker 3: And this is one of my favorite parts of science
• 11:17
  Speaker 3: fiction is thinking about the consequences, like you've created this
• 11:21
  Speaker 3: new technology or discovered this new bit of science, what
• 11:23
  Speaker 3: does that mean? Not just for like what is it
• 11:25
  Speaker 3: like to be human? In that universe, but what are
• 11:27
  Speaker 3: the experiences like.
• 11:29
  Speaker 2: Of using it? And the best science fiction.
• 11:31
  Speaker 3: Are the ones that have really thought this through and
• 11:33
  Speaker 3: come up with creative or interesting or surprising results.
• 11:36
  Speaker 1: It's like in a B movie, the science fiction B
• 11:39
  Speaker 1: movie where it asks if bees were sentient and all
• 11:42
  Speaker 1: went on strike, would that be good or bad for
• 11:46
  Speaker 1: the planet. But we were talking about some of the
• 11:49
  Speaker 1: best science fiction movies, so of course I thought of
• 11:51
  Speaker 1: B movie, but going.
• 11:53
  Speaker 3: Absolutely yeah, definitely a high point in the science fiction
• 11:56
  Speaker 3: movie canon.
• 11:58
  Speaker 2: But in this case they're wondering.
• 11:59
  Speaker 3: Like, well, it look like if you looked out the
• 12:01
  Speaker 3: window while you were going faster than the speed of light,
• 12:04
  Speaker 3: which is a really cool question. And the writers on
• 12:07
  Speaker 3: these TV shows, or the visualization artists or wherever it's
• 12:10
  Speaker 3: responsible for this, typically do this by making the stars
• 12:14
  Speaker 3: streak by right like you see this in Star Wars
• 12:17
  Speaker 3: the stars go from points to these lines, and on
• 12:20
  Speaker 3: Star Trek they have this particular visualization where the stars
• 12:23
  Speaker 3: aren't completely solid lines, they sort of zoom by, so
• 12:26
  Speaker 3: it looks like you're whizzing through the universe and seeing
• 12:29
  Speaker 3: the stars go by really fast. And the question is like,
• 12:33
  Speaker 3: would you really be able to see the stars, because
• 12:35
  Speaker 3: wouldn't their frequency be shifted by the Doppler effect, so
• 12:39
  Speaker 3: they'd be so blue that you couldn't see them. The
• 12:42
  Speaker 3: Doppler effect being that if something is moving relative to you,
• 12:45
  Speaker 3: the light it emits changes frequencies. So, for example, stars
• 12:49
  Speaker 3: from other distant galaxies are all moving away from us
• 12:52
  Speaker 3: as the universe is expanding, and so the light from
• 12:55
  Speaker 3: those stars is shifted red because the stars are moving
• 12:58
  Speaker 3: away from us, Galaxies like Andromeda are moving towards us,
• 13:02
  Speaker 3: so light from Andromeda is shifted blue. So if you
• 13:05
  Speaker 3: were right next to Andromeda and not moving relative to it.
• 13:08
  Speaker 2: You would see it's pure light as it's actually emitted.
• 13:11
  Speaker 3: We see that light at higher frequencies it's blue shifted
• 13:14
  Speaker 3: more towards ultraviolet and X ray then it would be
• 13:18
  Speaker 3: if we weren't moving relative to Andromeda. It's actually a
• 13:20
  Speaker 3: really powerful way to measure the velocity of distant stuff
• 13:24
  Speaker 3: by measuring its red shift or its blue shift. So
• 13:26
  Speaker 3: the question is asking, like, wouldn't the stars out the
• 13:29
  Speaker 3: window be so blue shifted that they would be invisible?
• 13:32
  Speaker 1: I see right, Because if you're moving away or towards something,
• 13:36
  Speaker 1: it's like the wavelength of that light that would be
• 13:39
  Speaker 1: hitting your eye is going to change.
• 13:41
  Speaker 2: Yeah, exactly.
• 13:42
  Speaker 3: It's basic physics of the Doppler effect. It's like when
• 13:45
  Speaker 3: a police siren is coming towards you, it sounds one way,
• 13:47
  Speaker 3: and when it's moving away from you, it sounds another way.
• 13:49
  Speaker 3: It's the same effect but applied to sound.
• 13:51
  Speaker 1: Yeah, it sounds like we woo we woo, and it
• 13:54
  Speaker 1: goes like wee woo woo woo.
• 13:57
  Speaker 2: Yeah exactly.
• 13:59
  Speaker 3: And that also for light, because light is a wave
• 14:01
  Speaker 3: in the electromagnetic field. And so he's asking about that,
• 14:05
  Speaker 3: and so I did a little bit of digging into
• 14:07
  Speaker 3: the physics of star trek warp drives, and I was
• 14:10
  Speaker 3: wondering also, like why are we seeing stars whoosh by?
• 14:13
  Speaker 3: Like is that realistic?
• 14:15
  Speaker 1: Right?
• 14:16
  Speaker 3: Because warp nine is pretty fast, but it's not actually
• 14:18
  Speaker 3: that fast. Like I said, it takes two days to
• 14:21
  Speaker 3: go like ten light years. But if you look at
• 14:24
  Speaker 3: the window of the enterprise, you see stars whoshing by
• 14:27
  Speaker 3: all the time. The thing is that stars are way
• 14:29
  Speaker 3: too far apart for that to happen. Yeah, I mean
• 14:32
  Speaker 3: stars are typically like three four five light years apart.
• 14:36
  Speaker 3: So if you're only going ten light years every two days,
• 14:39
  Speaker 3: then you should see like a star whoosh by like
• 14:41
  Speaker 3: every twenty four hours. But if you look at the
• 14:44
  Speaker 3: window of the enterprise, it's like ten stars a second.
• 14:46
  Speaker 3: So they've taken some real liberties in that visualization.
• 14:50
  Speaker 1: I mean one way, I know that Star Trek is
• 14:52
  Speaker 1: sort of not going with the we are scrunching up space.
• 14:57
  Speaker 1: But if you were scrunching up space, I could see
• 14:59
  Speaker 1: an argument for there being some kind of weird optical effect.
• 15:04
  Speaker 1: Not necessarily stars wooshing by, but you know, I remember
• 15:08
  Speaker 1: in an episode where we talked about your point of
• 15:10
  Speaker 1: view from a black hole, where it's like if you
• 15:13
  Speaker 1: have a very dense point where it would suck in light.
• 15:17
  Speaker 1: So maybe if you're scrunching space, you could I don't
• 15:21
  Speaker 1: know exactly how this would work. I'm now beyond my understanding,
• 15:27
  Speaker 1: but I guess there could be some kind of weird
• 15:29
  Speaker 1: optical effect.
• 15:32
  Speaker 3: I think that kind of creativity in science should get
• 15:35
  Speaker 3: you a spot as physics consultation on Star Trek.
• 15:39
  Speaker 1: Sweet so I can just say, uh, oh, the gasorp
• 15:42
  Speaker 1: azorp drive went down.
• 15:46
  Speaker 3: No, I think there's a lot of room for like,
• 15:47
  Speaker 3: how could we make this work? What would you have
• 15:50
  Speaker 3: to do is there any explanation in science? But anyway,
• 15:53
  Speaker 3: let's take the star trek warp drive and just say
• 15:55
  Speaker 3: somehow it makes you be able to move faster than
• 15:58
  Speaker 3: the speed of light. Physics is spended or we've discovered
• 16:01
  Speaker 3: if the special relativity is wrong or whatever. We're moving
• 16:04
  Speaker 3: faster than the speed of light. What would it look
• 16:05
  Speaker 3: like out the window, the front window, the side window,
• 16:08
  Speaker 3: the back window. And Dale's totally right that the Doppler
• 16:11
  Speaker 3: effect is a big effect. You're moving very fast relative
• 16:14
  Speaker 3: to these stars, which is the same thing as saying
• 16:16
  Speaker 3: they're moving fast relative to you. So, for example, if
• 16:19
  Speaker 3: you look out the back window of the Enterprise, you're
• 16:22
  Speaker 3: moving faster than the speed of light. Number one, all
• 16:25
  Speaker 3: of the light from those stars is really really red shifted.
• 16:28
  Speaker 3: It's red shifted so far that you wouldn't be able
• 16:31
  Speaker 3: to see it like our sun amids light in the
• 16:34
  Speaker 3: visual spectrum. But if you're moving away from the Sun
• 16:36
  Speaker 3: super duper fast, then its light is going to be
• 16:39
  Speaker 3: red shifted so far that you'd need like a special
• 16:42
  Speaker 3: infrared camera to even pick it up.
• 16:44
  Speaker 1: I see, yeah, because our eyes can only detect certain wavelengths,
• 16:48
  Speaker 1: like if something's too I guess wide of a wavelength
• 16:53
  Speaker 1: or too short of a wavelength, we are not going
• 16:55
  Speaker 1: to be able to see it.
• 16:56
  Speaker 2: Yeah exactly.
• 16:57
  Speaker 3: And in addition, you're now moving faster than those photons somehow, right,
• 17:01
  Speaker 3: we suspended physics, and so you're out running the photons,
• 17:05
  Speaker 3: so you're not going to be able to see anything
• 17:07
  Speaker 3: behind you.
• 17:08
  Speaker 2: Yeah exactly.
• 17:10
  Speaker 3: So it's like I'm trying to throw a baseball at you,
• 17:12
  Speaker 3: but you're in your ferrari and you're going much faster,
• 17:14
  Speaker 3: Like my baseball is not going to get to you.
• 17:17
  Speaker 3: So you're just not going to see anything out the
• 17:19
  Speaker 3: back window. If you're actually moving faster than the speed
• 17:22
  Speaker 3: of light. But then what about your front window? Right,
• 17:24
  Speaker 3: you're moving towards all these stars faster than the speed
• 17:27
  Speaker 3: of light.
• 17:28
  Speaker 2: What should you see?
• 17:29
  Speaker 1: Right?
• 17:29
  Speaker 3: This is actually also quite counterintuitive what you would actually see.
• 17:33
  Speaker 3: And instead of imagining ourselves moving towards the stars, imagine
• 17:37
  Speaker 3: the equivalent scenario of the star moving towards us. Because
• 17:40
  Speaker 3: in our universe velocity is relative, it doesn't really matter
• 17:43
  Speaker 3: who's moving.
• 17:44
  Speaker 2: It's actually the same thing.
• 17:45
  Speaker 3: Think about what it would look like if a star
• 17:47
  Speaker 3: is moving towards you faster than the speed of.
• 17:49
  Speaker 1: Light scary, you actually be very scary.
• 17:54
  Speaker 2: Now.
• 17:54
  Speaker 3: That means that the star is moving faster than the
• 17:57
  Speaker 3: light that it emits, right, right, So it's like leaving
• 18:01
  Speaker 3: the light behind, which means again you can't see it,
• 18:05
  Speaker 3: right because you arrive at the star before the light
• 18:07
  Speaker 3: that it emitted along the way it gets to you.
• 18:10
  Speaker 1: Ah my brain.
• 18:13
  Speaker 2: Yeah right.
• 18:14
  Speaker 3: And so imagine the star is far away, it emits
• 18:16
  Speaker 3: a photon, but the star gets to you before the photon, right,
• 18:20
  Speaker 3: So you don't see that photon until the star has
• 18:22
  Speaker 3: already passed you. So what happens is as the star
• 18:25
  Speaker 3: passes you, that's when you see it, and you actually
• 18:28
  Speaker 3: see it twice. You still go past you, and now
• 18:30
  Speaker 3: it's emitting photons as it goes past you, and those
• 18:33
  Speaker 3: photons are coming towards you, and you also start to
• 18:36
  Speaker 3: receive the photons that it emitted while it was on
• 18:39
  Speaker 3: its way to you. Those now start arriving, but they
• 18:42
  Speaker 3: arrive in reverse order, right, because the images it's sent
• 18:46
  Speaker 3: later arrived before the images it's sent earlier when it
• 18:50
  Speaker 3: was further away.
• 18:51
  Speaker 1: Oh yeah, Because you are moving so fast that you
• 18:54
  Speaker 1: will approach the star and have those close by photons
• 19:00
  Speaker 1: you faster than the ones that hit you from when
• 19:04
  Speaker 1: the star was further away. Yeah, that's wild. You'd see
• 19:09
  Speaker 1: like an after image of the star before from before.
• 19:13
  Speaker 3: Yes, exactly, So you'd see nothing, and then when the
• 19:15
  Speaker 3: star passes you, you'd suddenly see two stars.
• 19:18
  Speaker 2: One going behind you and one going ahead of you.
• 19:21
  Speaker 3: It would look like going backwards in time, right, you
• 19:24
  Speaker 3: would see it in reverse order.
• 19:26
  Speaker 2: Very bizarre effect.
• 19:27
  Speaker 3: And I've never seen this displayed in science fiction. I
• 19:30
  Speaker 3: would love to see somebody actually make this work. If
• 19:33
  Speaker 3: you were writing a new show about people with warp drives,
• 19:36
  Speaker 3: email me and I will help you get this right.
• 19:38
  Speaker 1: Well, I'm going to keep that in mind for my
• 19:40
  Speaker 1: new show Hot Alien Babes on Neptune.
• 19:45
  Speaker 3: Dale's actual question is about the light, and he's right
• 19:47
  Speaker 3: that the light is also going to be blue shifted,
• 19:50
  Speaker 3: and so if it was like originally a red dwarf
• 19:52
  Speaker 3: that emitted in the longer wavelengths, it would be shifted
• 19:55
  Speaker 3: into the higher frequencies. The exact shift depends on the velocity,
• 20:00
  Speaker 3: but he's right that that might also be invisible. It
• 20:02
  Speaker 3: might be that is shifted up way past the ultraviolet,
• 20:06
  Speaker 3: so that you need like X ray sensors or gamma
• 20:08
  Speaker 3: ray sensors to be able to detect it. In principle,
• 20:11
  Speaker 3: there's nothing that's actually invisible, Like if we have enough
• 20:14
  Speaker 3: particle detectors, we can sense those very very high frequency photons.
• 20:18
  Speaker 3: For example, orbiting the Earth, we have the Fermi Lat telescope,
• 20:21
  Speaker 3: which you can measure photons at very very high energies.
• 20:25
  Speaker 3: So in principle you imagine that these spaceships are probably
• 20:28
  Speaker 3: equipped with sensors to be able to detect super high
• 20:30
  Speaker 3: frequency photons, but you wouldn't see them with the naked eye, okay,
• 20:34
  Speaker 3: but you might see something else. You know that the
• 20:37
  Speaker 3: universe is filled with the cosmic microwave background photons, photons
• 20:41
  Speaker 3: left over from a very early universe plasma, and these
• 20:44
  Speaker 3: are very long wavelength because they've been stretched to very
• 20:48
  Speaker 3: very infrared by the expansion of the universe. But if
• 20:52
  Speaker 3: you're flying through the universe faster than the speed of light,
• 20:55
  Speaker 3: those are all going to.
• 20:56
  Speaker 2: Get blue shifted.
• 20:57
  Speaker 1: It hits crunched up.
• 20:58
  Speaker 2: Yeah, they might.
• 20:59
  Speaker 3: Get blue shifted all all the way into the visible spectrum.
• 21:01
  Speaker 3: So you might be able to see the CMB with
• 21:04
  Speaker 3: your naked eyes, meaning that the whole universe would be
• 21:07
  Speaker 3: filled with this fog.
• 21:09
  Speaker 1: Oh whoa, it might maybe you would get some kind
• 21:11
  Speaker 1: of weird spaceship Aura.
• 21:14
  Speaker 2: Yeah, would be super cool.
• 21:17
  Speaker 3: Anyway, Dale is totally right that the way they describe
• 21:19
  Speaker 3: it on Star Trek is not really accurate from the
• 21:22
  Speaker 3: physics point of view, and the engine they have anyway
• 21:25
  Speaker 3: doesn't really make any sense. But it's a lot of fun.
• 21:27
  Speaker 3: I don't mean that in a way to criticize Star Trek.
• 21:29
  Speaker 3: I know what they're going for is not hard sci fi.
• 21:32
  Speaker 3: There's definitely a niche there, and I love it big
• 21:34
  Speaker 3: fans Star Trek.
• 21:35
  Speaker 1: I hope one of those writers were fired for that
• 21:38
  Speaker 1: blunder is my opinion.
• 21:40
  Speaker 3: No, no, no fire any writers or pro writer. But
• 21:44
  Speaker 3: please do reach out to us. We would love to
• 21:46
  Speaker 3: help you get the physics right. And thank you to
• 21:49
  Speaker 3: Dale for reaching out to us with your question about
• 21:51
  Speaker 3: the physics of Star Trek. I love that Dale, that
• 21:53
  Speaker 3: is doing this physics in his mind, he's being a physicist.
• 21:56
  Speaker 3: He's wondering what would this actually look like? How does
• 21:58
  Speaker 3: that work? Why not this one that's being a physicist.
• 22:02
  Speaker 3: All you people out there who are wondering how the
• 22:04
  Speaker 3: universe works, you're all physicists too sweet.
• 22:07
  Speaker 1: Did we get a badge?
• 22:09
  Speaker 2: I'll send you all a sticker.
• 22:10
  Speaker 3: Yes, digital we get a badge, all right, so please
• 22:15
  Speaker 3: don't be shy right to us with your questions to
• 22:17
  Speaker 3: questions Aunt Daniel and Jorge dot com. Everybody gets an answer,
• 22:21
  Speaker 3: because everybody deserves an explanation. Thanks Katie very much for
• 22:24
  Speaker 3: joining me on today's special listener Questions sixty nine episode.
• 22:28
  Speaker 1: All right, back to work on my hot babes from
• 22:30
  Speaker 1: Neptune script.
• 22:32
  Speaker 3: Can't wait to see that one on the screen. All right, everyone,
• 22:35
  Speaker 3: Thanks very much. Tune in next time for more science
• 22:42
  Speaker 3: and curiosity. Come find us on social media where we
• 22:45
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• 22:49
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• 22:53
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• 22:57
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