Latest / Star Trails: From Backyard Astronomy to Cosmic Wonder / Playing Dice with the Universe

Transcript

Playing Dice with the Universe · Star Trails: From Backyard Astronomy to Cosmic Wonder

0:07
Howdy Star Gazers and welcome to this episode
0:10
of Star Trails. My name is Drew and I'll be your
0:14
guide to the night sky for the week of November
0:16
the 9th to the 15th. This week we're going to
0:21
kick things off with yet another exercise related
0:24
to a subject that I find endlessly fascinating.
0:28
We're going to take another look at the Drake
0:30
Equation, a tool used to estimate how many intelligent
0:34
species we might have in our home galaxy. And
0:38
we're going to use that equation to simulate
0:40
more than a million variations of the Milky Way,
0:44
employing some quantum physics along the way
0:47
to kickstart our experiment. I think you're going
0:50
to be blown away by the implications, because
0:53
I know I was. Later, we'll check in on the night
0:57
sky and I'll tell you how I captured an image
1:00
of last week's full beaver moon using some of
1:03
my favorite astronomy smartphone apps. Whether
1:07
you're tuning in from the backyard, the balcony,
1:09
or just your imagination, I'm glad you're here.
1:13
So grab a comfortable spot and let's see what
1:15
the universe holds for us this week. A couple
1:19
weeks ago, we explored the Fermi paradox, the
1:23
idea that in a universe so vast, we should be
1:26
hearing or seeing indications of intelligent
1:30
life. Yet, here we are in the cosmic void, seemingly
1:34
all by ourselves. For the past 50 years or more,
1:40
programs like the Search for Extraterrestrial
1:42
Intelligence, or SETI, have churned away, theorizing
1:46
and scanning the skies with radio telescopes
1:49
in search of something, anything, to tell us
1:52
that we're not alone. And for two decades, volunteers
1:57
even donated their CPU cycles to analyzing radio
2:00
data via the SETI At Home Project. pioneering
2:05
distributed computing methodologies in the process.
2:09
And so far we've found nothing. But surely something
2:14
must be out there. So in this episode, we'll
2:18
turn to the world of statistics and data analysis,
2:22
and I promise it's not going to be as boring
2:24
as it sounds. We're going to use a quantum computer
2:28
to tap into the inherent randomness of the universe
2:32
itself. And we're going to use that information
2:35
to run the Drake Equation more than a million
2:39
times. We're going to play dice with the universe
2:43
and explore the probability of extraterrestrial
2:46
life. To start, let's get a refresher on what
2:52
the Drake Equation is. I've sort of had a lifelong
2:56
fascination with it since I cracked open Carl
2:59
Sagan's Cosmos as a preteen and I first encountered
3:03
it. The idea that an equation could make a prediction
3:07
about the density of alien life sparked profound
3:11
wonder in me at that age. We talked about it
3:15
in some detail back in episode 85, the silence
3:19
between the stars. Today we're going to dig in
3:22
a little deeper. You may recall from that earlier
3:26
episode that the Drake equation was an attempt
3:28
by scientist Frank Drake to mathematically make
3:32
sense of the Fermi paradox. In 1961, Drake hosted
3:38
a small meeting at the Green Bank Observatory
3:41
in West Virginia, the first gathering devoted
3:44
to the search for extraterrestrial intelligence.
3:47
He scribbled a simple formula on a blackboard
3:50
to structure the discussion. It's really just
3:53
a series of numbers that we multiply together.
3:56
Here's the equation. And if you were counting,
4:12
that's just seven variables. It's almost unnervingly
4:16
simple on the surface. Seven factors. Seven cosmic
4:21
knobs, if you will. and it breaks down like this.
4:25
R is the average rate of star formation in our
4:29
galaxy. Fp is the fraction of those stars with
4:34
planets. Ne is the average number of planets
4:39
that can potentially support life. F1 is the
4:43
fraction of planets that actually develop life.
4:47
Fi is the fraction of planets that develop intelligent
4:51
life. FC is the fraction of civilizations that
4:56
release signs of their existence into space.
5:00
And L is the length of time such civilizations
5:03
release those signals of their existence. Just
5:07
multiply them all together and you get N, the
5:11
number of intelligent civilizations in the Milky
5:14
Way right now. But this is where the simplicity
5:18
collapses, because we don't know any of those
5:21
variables with any confidence. We only have one
5:25
biological data point, that's us. We have one
5:29
technological species data point, that's us again.
5:33
We have one lifetime data point, also us. And
5:38
since we don't know where our own story ends
5:41
yet, even that data point is incomplete. So when
5:45
people plug numbers into Drake and they solve
5:48
for in that neat answer is an illusion Drake
5:52
isn't an equation you simply solve it forces
5:56
you to confront the fact that everything important
5:58
in that multiplication is unknown So what do
6:03
you do with an equation whose inputs are unknown
6:07
you treat those inputs probabilistically You
6:11
don't just pick single values, you define plausible
6:14
ranges based on astrophysics, exoplanet surveys,
6:19
and reasonable scientific priors. And then you
6:22
sample from those ranges again and again and
6:25
again. You generate not one answer, but a landscape
6:30
of possible answers, a distribution. This is
6:36
how modern SETI researchers think about Drake,
6:39
not as an answer machine, but as a probability
6:42
engine. So in that spirit, we're about to run
6:46
some code to Big Bang more than a million versions
6:50
of the Milky Way and see what those universes
6:53
tell us. We are in effect gambling with the universe's
6:57
uncertainty, and we're going to roll nature's
7:00
dice using some quantum mechanics. Einstein famously
7:06
said, God does not play dice with the universe.
7:10
He wasn't a fan of quantum randomness and he
7:13
believed the laws governing the universe were
7:15
fixed. But we're going to play dice with the
7:19
universe anyway. My apologies to Albert. Here's
7:23
the plan. We're going to make use of the general
7:27
programming language of Python to produce more
7:30
than a million outcomes of the Drake equation.
7:33
The program will randomly select a number for
7:36
each variable from a predefined range of conservative,
7:40
educated estimates for each. Think of it as generating
7:44
a million versions of the Milky Way. The predefined
7:48
ranges for each variable are the glue that makes
7:51
this work. We're going to use some plausible
7:54
data drawn from everything we know about the
7:56
universe and everything we don't. These aren't
8:00
my ranges, by the way. These are some widely
8:03
accepted best -guess envelopes based on papers,
8:07
expert intuition, SETI tradition, astrobiology,
8:11
and more. Once the program runs, we'll analyze
8:16
the resulting data. We're looking for two extremes,
8:19
the highest number of estimated intelligent civilizations
8:23
compared to the lowest number, and we'll be on
8:26
the lookout for a zero result. meaning an iteration
8:30
produced no intelligent civilizations. This approach
8:34
is called a Monte Carlo simulation. To add some
8:39
philosophical flair, I specifically wanted to
8:43
seed my sim with a 128 -bit random number produced
8:48
by a quantum computer. It sounds like science
8:52
fiction, but it's not. For this experiment, I
8:55
used IBM's quantum computing platform via their
9:00
Qiskit framework. It's a real quantum computer
9:04
that we can rent time on. It isn't a simulation.
9:07
It's actual superconducting qubits chilling near
9:11
absolute zero. Why 128 bits? Well, this is a
9:17
cryptography grade random number. It represents
9:21
2 to the 128th power in terms of possible outcomes.
9:27
That's more possibilities than there are atoms
9:29
in a typical galaxy. We wrote a simple quantum
9:34
random number generator, a QRNG in Python, with
9:39
some help from an AI, because this realm is way
9:42
beyond my skill set. This code essentially generates
9:46
128 quantum coin flips. And if you think creating
9:52
a quantum random number generator sounds like
9:55
overkill for what's usually a simple randomized
9:58
function in almost every programming language,
10:01
you're not wrong. But we're using quantum physics
10:04
to generate this number because that's about
10:06
as close as we can get to asking the universe
10:08
itself for randomness. The quantum computer is
10:13
literally driven by the uncertainty built into
10:16
the fabric of reality. Quantum computers don't
10:20
use bits, the ones and zeros used in classical
10:24
computers. They use qubits, which are similar
10:28
to traditional bits, but they can exist in a
10:30
state of superposition, meaning they could either
10:33
be a zero or a one. In fact, they have no state
10:37
until they're measured, meaning they hold multiple
10:40
possibilities until we force an outcome. You
10:44
may have heard this called the observer effect
10:46
when it comes to quantum mechanics. You may have
10:49
also heard of the thought experiment known as
10:52
Schrodinger's cat, a feline in a box that exists
10:57
in both an alive and dead state, until we open
11:00
the box and look at it. That's quantum mechanics
11:04
at its most basic, and that's also why it's so
11:07
weird. These are behaviors at the smallest level
11:10
of existence, individual particles. Our Python
11:16
script constructed a tiny quantum circuit that
11:19
creates qubits in superposition and collapses
11:22
them when they're measured. And we harvested
11:25
the randomness from that collapse to generate
11:28
our seed. Essentially, we fire qubits through
11:32
a series of quantum logic gates 128 times. The
11:37
gates force the qubits into a one or zero outcome.
11:42
Once we have 128 ones and zeros, we convert that
11:45
binary string into base 10 decimal, and that
11:49
extremely random number becomes the seed. Strangely,
11:53
operating a quantum computer reminds me of the
11:56
old mainframe systems of the 60s and 70s. To
12:00
use one, you submit a job to it. Your job waits
12:04
in a queue until the machine can run your code,
12:07
then it returns a result. IBM's Qiskit framework
12:12
lets you both simulate a quantum computer and
12:15
send jobs to their real one via a public application
12:19
programming interface, or API in coding parlance.
12:25
So before I started burning qubits on the real
12:27
hardware, I ran a local sim to make sure the
12:30
code worked as intended. When I was satisfied
12:33
with the output, I submitted the job to IBM and
12:36
waited a minute or two for the result to come
12:39
back. And there it was, a QRNG seed, the randomness
12:45
that sets our experiment into motion. And let
12:48
me tell you, that was a lot of work to get a
12:51
random number. But the beauty of this method
12:54
would reveal itself later in a moment of realization
12:57
that left me in a state of both shock and awe.
13:02
The rest of our calculations would take place
13:04
in a very simple Python script here on my workstation.
13:08
And by the way, I'll make all of my code available
13:11
if you want to try and run it. Check the show
13:13
notes for details. In classical computing, a
13:18
seed initializes the random number generator
13:21
in your programming language of choice. Once
13:24
you have a seed, every random number after that
13:27
traces back to that original seed. We're starting
13:31
with a quantum seed, but we're turning that chaos
13:34
into classical determinism. On the first run,
13:43
I set up my script to generate 250 ,000 solved
13:47
versions of the Drake equation. It ran in seconds.
13:51
Think of each version as one possible cosmic
13:53
outcome. Basically, we simulated a quarter million
13:57
pocket universes, each with its own set of Drake
14:00
parameters. Some outcomes produced thousands
14:04
of intelligent species, some produced hundreds.
14:07
The maximum seemed to land somewhere just under
14:10
a quarter million intelligent species in the
14:13
galaxy. That's pretty insane. Most runs produced
14:17
galaxies with at least 700 species. So I ran
14:22
the Monte Carlo sim again, this time with a half
14:26
million outcomes, then a million, and then two
14:29
million. Strangely, the numbers didn't vary by
14:33
much, but here's the part that hit me like a
14:36
dinosaur -killing asteroid. In each run, seeded
14:40
by that actual quantum hardware, zero universes
14:44
came up empty. Zero. In other words, all the
14:49
universes we simulated produced intelligent life,
14:53
based on the conservative range of values we
14:56
plugged into the Drake equation. Let me state
15:01
that another way. A real quantum mechanical process,
15:05
not a software algorithm, but a literal collapse
15:08
event inside superconducting hardware gave us
15:12
a seed that led to a distribution of data that
15:15
tells us we're probably not alone in the universe.
15:19
I don't think I breathed for about a full minute
15:22
as this realization washed over me, and even
15:25
now I get chills thinking about it. Now this
15:28
doesn't mean we've proven anything. It doesn't
15:31
mean aliens are guaranteed. It doesn't mean the
15:33
equation reveals the truth. But it does mean
15:36
that when you explore the space of plausible
15:39
Milky Ways with honest scientific uncertainty,
15:43
there's almost no chance that we're alone. And
15:47
just for fun, I tried to get absurd. I tried
15:49
to simulate a billion universes. That's when
15:53
my workstation threw up the white flag. The CPU,
15:57
all 24 cores of it, shot up to its maximum 5
16:01
GHz clock speed. The RAM usage hit the ceiling
16:04
at 64 gigs and the cooling fans spun up like
16:08
jet engines. It completely choked and the funny
16:11
thing is it didn't really matter. We already
16:13
saw everything we needed to see back at a quarter
16:16
million samples. And it was completely stable
16:19
by one million. The shape of the uncertainty
16:22
reveals itself quickly. And throwing more universes
16:26
at it doesn't make reality any more certain.
16:30
You just generate heat and thermodynamic suffering
16:33
on the CPU. This Monte Carlo exercise, this million
16:40
universe experiment, it isn't meant to be proof,
16:43
it simply offers perspective. We don't get a
16:46
single number from Drake. We get a distribution
16:50
of possibility. And inside that distribution,
16:53
the middle ground, the typical universe, contains
16:56
neighbors, sometimes a few, sometimes many. And
17:00
we didn't bias that outcome with wishful thinking.
17:03
We seeded that simulation with randomness drawn
17:07
from quantum measurement, the most fundamental
17:10
unpredictability that nature gives us. People
17:14
think the Drake equation is about estimating
17:17
aliens. I think it's actually about estimating
17:20
ourselves. It forces us to confront how narrow
17:23
our experience is and how broad the universe
17:26
might be. The Fermi paradox wonders, where is
17:35
everybody? Drake tells us there might be many
17:38
somebodies, but probability and distance and
17:41
lifetimes might keep us apart. Scientists working
17:46
on Drake today are pushing into better estimations,
17:49
especially around habitable planets and biosignatures.
17:53
The James Webb Space Telescope and future missions
17:56
may eventually constrain the F1 parameter, life
18:00
emergence, far more than we ever could before.
18:04
Exoplanet atmospheric chemistry may eventually
18:07
give us actual statistics, not just speculative
18:10
boundaries. And the biggest uncertainty, L, the
18:14
lifetime of communicative civilizations, may
18:17
be the most existential. Because its true value
18:21
might say more about our future than our past.
18:27
And maybe that's the deepest irony here. The
18:30
Drake Equation may eventually tell us more about
18:33
what kind of species we're capable of becoming
18:36
than it tells us about the species that already
18:39
exist somewhere else. With that, let's step out
18:46
of the multiverse and drop back into the single
18:48
universe we inhabit, the one overhead tonight,
18:52
and talk about what's happening in the real night
18:54
sky this week. That's coming up after the break.
18:58
Stay with us. Welcome back. Before we get into
19:15
this week's sky, I wanted to give another quick
19:17
observation report. As you all recall, the full
19:21
moon was last week and it was a supermoon. Sometimes
19:25
I enjoy photographing a full moon. My favorite
19:28
shots show the moon in relation to the urban
19:31
landscape. I love how the moon looks gigantic
19:34
near the horizon, an effect we call the moon
19:37
illusion. It's not bigger, it just seems bigger
19:40
when it's adjacent to objects that we already
19:43
understand the scale of. So last Tuesday was
19:47
a gorgeous clear evening, and I didn't have any
19:49
after work commitments So I drove out to a location
19:53
I've shot from in the past a highway overpass
19:56
just outside the city that faces due east Using
20:01
a 200 millimeter lens on my full -frame camera
20:04
I managed to capture a massive moon just as it
20:07
rose over the skyline I only had a few minutes
20:11
to get the shot as once the moon rises higher
20:13
and the ambient light dips, it's hard to balance
20:17
the moon's brightness with the city's darkness.
20:20
Twilight, with some light in the sky, works the
20:22
best. If you'd like to see the photo, check the
20:26
show notes for a link. And just know that capturing
20:30
a shot like this isn't luck, it's planning. There
20:33
are three apps I lean on when I want to line
20:36
up the moon precisely with the skyline. Stellarium,
20:40
photo pills, and the photographer's ephemeris.
20:44
Stellarium gives me the astronomy first view.
20:47
I can preview the night sky exactly as it will
20:50
appear from my location, jump forward in time,
20:54
and verify altitude and azimuth. That tells me
20:57
when and where the moon will be above the horizon.
21:02
Photo pills takes that same information and grounds
21:05
it into the language photographers think in.
21:08
exact rise time, exact bearing, and whether the
21:11
moon's trajectory will intersect a specific place
21:15
on Earth, if I stand right here. This app uses
21:19
augmented reality to help you place the moon
21:21
or sun in your scene. I can check focal lengths,
21:25
distances, compression, and get confidence that
21:28
the scale will look right. And the photographer's
21:31
ephemeris helps lock the terrestrial geometry
21:34
in. That's the piece that tells me where to physically
21:37
stand, which road, which hilltop, and even which
21:41
building the moon will appear behind. It shows
21:44
the rise line across the map, and I can drag
21:48
my shooting location until the moon's path intersects
21:51
the exact building I want. Together, those three
21:55
apps turn an event that looks lucky into something
21:58
you can intentionally design, days or even weeks
22:01
ahead of time. The shot begins before you ever
22:05
set the tripod down. I'll include links in the
22:09
show notes to these resources if you're interested.
22:18
This week the moon slides from a waning gibbous
22:21
toward the last quarter phase, which happens
22:23
on Wednesday, the 12th, and the very early hours
22:27
of the morning. After that, the moon shrinks
22:30
into a thinner crescent each night, which means
22:32
a darker sky window is opening up as we head
22:35
toward the weekend. Saturn still rules the early
22:39
evening sky over in the southeast. The rings
22:42
are almost edge -on now, so in a telescope they're
22:45
a fine thin line. Jupiter steals the second half
22:49
of the night. It rises later in the evening and
22:51
is high before dawn. The moon makes a close pass
22:55
with Jupiter Monday night into Tuesday morning,
22:58
so if you're out late or awake before sunrise
23:00
on the 11th, take a look for that pairing. Uranus
23:04
is also in the evening sky and headed toward
23:07
opposition later this month. If you have binoculars
23:10
and a dark sky, spend a little time trying to
23:13
pick it out. It'll look like a tiny blue -green
23:16
star. Neptune is in the evenings too, but you'll
23:20
need a telescope. Venus is now extremely low
23:24
in the morning twilight. If you have a clear
23:27
flat eastern horizon, you might catch it in the
23:30
dawn light later in the week. Especially if you
23:33
pair it with the delicate crescent moon Friday
23:35
or Saturday morning. Mars and Mercury, meanwhile,
23:39
are essentially lost in the sun's glare. We also
23:43
have some meteor action this week. The northern
23:47
taurids peak on Tuesday night into Wednesday,
23:50
the 11th into the 12th. This is not a high -rate
23:54
shower, but the taurids are known for bright,
23:56
slow fireballs. Moonlight will wash out the dimmer
24:00
ones, but if you're patient, you might still
24:02
spot a good one. And the Leonids are right behind
24:06
them. Their main peak will arrive next week under
24:09
much better moon conditions. The deep sky season
24:13
continues to get better as the moon wanes. The
24:16
Andromeda galaxy is high after dark. So are the
24:19
Pleiades and the Hyades, perfect binocular targets.
24:25
You know, at the end of all this, numbers are
24:28
only part of why we look up. The equations, the
24:32
instruments, the simulations, they help us measure
24:35
possibility. But wonder lives before measurement.
24:40
Wonder is older than science. Wonder is the first
24:43
tool we ever had. When we look at the night sky,
24:47
we aren't just observing the universe. We're
24:49
also observing ourselves. The cosmos isn't just
24:53
a place we study. It's a mirror that we hold
24:56
up to our own short, small moment in time. So
25:00
yes, we count stars, we model probability, we
25:04
write code, we build telescopes, but beneath
25:07
all that we're trying to remember that being
25:09
alive is strange and extraordinary, and the very
25:13
act of wondering is itself part of what makes
25:16
us human. We look up not just because the sky
25:20
is beautiful, but because it reminds us that
25:23
there's always more to know, and that curiosity
25:26
is a kind of hope. If you found this episode
25:33
interesting, please share it with a friend who
25:35
might enjoy it. The easiest way to do that is
25:38
by sending folks to our website, StarTrails .Show.
25:42
And if you want to support us, use the link on
25:44
the site to buy me a coffee. It really helps.
25:48
Be sure to follow Star Trails on Blue Sky and
25:51
YouTube. Links are in the show notes. Until we
25:54
meet again beneath the stars, clear skies, everyone.