
20220720: What If We Live in a Superdeterministic Universe?
 11:54: And that’s … impossible because if you trace the past lightcone of any two points in the observable universe back far enough they will overlap.


20220420: Does the Universe Create Itself?
 16:10: ... the cosmic event horizon would have wavelength roughly the size of the observable universe. Unfortunately that makes it not very detectable without a universesized ...
 17:39: ... fact  if you calculate the size of a black hole with the mass of our observable universe  adding together all the stars, dark matter, other black holes, ...


20220323: Where Is The Center of The Universe?
 12:47: ... and that if you zoom out to many, many, many times larger than the observable universe, everything evens out ...


20220223: Are Cosmic Strings Cracks in the Universe?
 08:50: ... expanding universe stretched them up to the size of the observable universe. We actually expect multiple nucleation events in each causal ...


20220112: How To Simulate The Universe With DFT
 00:00: ... you used every particle in the observable universe to solve the schrodinger equation and do full quantum simulation of some ...


20211229: How to Find ALIEN Dyson Spheres
 12:08: There are hundreds of billions of galaxies in the observable universe.


20211005: Why Magnetic Monopoles SHOULD Exist
 12:16: ... things far apart that there may be very few remaining in our entire observable universe. ...


20210818: How Vacuum Decay Would Destroy The Universe
 10:10: ... for a single such bubble to be likely to appear somewhere in our observable universe. So, somewhere between vaguely unlikely and staggeringly ...


20201013: Do the Past and Future Exist?
 09:04: ... the effect is tiny, but the “present” at the edge of the observable universe veers back and forth by a couple of centuries every time you switch ...


20200728: What is a Theory of Everything: Livestream
 00:00: ... if we were able to figure out a way to communicate with a part of the observable universe or the universe that we're not within or some other universe even if ...


20200211: Are Axions Dark Matter?
 12:47: ... 13.5 billion years it would be around 10^10^50 times the size of our observable universe. And that sounds about right. He then compares that to an estimate of the ...
 15:20: ... that is itself large enough to fit all possible configurations of observable universe sized regions. The volume would want to be 10^10^123 (or 90) times our ...


20200203: Are there Infinite Versions of You?
 09:40: For our 46billion light year observable universe there are definitely no more than 2^10^123 possible unique configurations.
 09:52: As long as the greater universe has more than than that many observable universesized regions, one of them should be identical to this one.


20191118: Can You Observe a Typical Universe?
 00:45: ... Way is an ordinary galaxy among 100s of billions of galaxies in the observable universe. ...
 05:45: All particles in the observable universe were packed together in a subatomicsized dot.
 08:33: For example a fluctuation the size of a galaxy is insanely more likely than one the size of our observable universe.


20190930: How Many Universes Are There?
 12:51: But it still should NOT be surprising that we don’t see evidence of bubble collisions in our observable universe.


20190806: What Caused the Big Bang?
 00:43: ... being: why is matter and energy so smoothly spread out across the entire observable universe? ...


20190725: Deciphering The Vast Scale of the Universe
 00:30: In fact there are surely more entire worlds in the observable universe than there are grains of sand on this one.


20190516: The Cosmic Dark Ages
 00:04: ... era. Somewhere between 10 and 1000 billion trillion stars fill the observable universe with light. But there was a time before the first star ...


20190403: The Edge of an Infinite Universe
 00:37: For example we have the “observable universe” – that patch that we can see, and beyond which light has not yet had time to reach us.
 00:57: Our observable universe is like a tiny patch of land in a vast plain.


20190207: Sound Waves from the Beginning of Time
 13:43: Well, the answer is it depends on what size you consider. For the entire observable universe?


20181010: Computing a Universe Simulation
 03:34: ... that the maximum information content, the Bekenstein bound, of the observable universe is around 10 to the power of 120 bits based on its surface ...
 03:59: ... bound suggests that we could hold all of the information in the observable universe within a storage device smaller than the observable universe, which ...
 05:13: ... informationally speaking, you could store the entire observable universe of nonradiation particles on the surface area of a black hole the size ...
 08:04: ... the energy of the system, we use the mass of the observable universe, around 10 to the power of 52 kilograms, and then apply good old e equals ...


20181003: How to Detect Extra Dimensions
 08:14: ... itself, which defines the threedimensional structure on which our observable universe exists, can actually expand into the extra fourth spatial ...


20180920: Quantum Gravity and the Hardest Problem in Physics
 14:35: dabeste points out that it's important to emphasize that you're talking about the observable universe, not the entire universe.
 14:43: ... size of the storage device needed to store all of the information in the observable universe. ...


20180912: How Much Information is in the Universe?
 01:07: How much information does it take to describe the entire observable universe?
 05:04: ... observable universe has a surface area of 10 to the power of 120 to 10 to the power of 124 ...
 06:02: The observable universe contains something like 10 to the power of 80 protons.
 06:27: The cosmic microwave background has around 10 to the power of 89 photons across the observable universe.
 09:47: How large a black hole computer would you need in mass and radius to contain enough data to simulate the entire observable universe?
 15:24: ... reliably eliminate all of the 10 to the power of 80 protons in the observable universe, you need around 265 halflives, or 10 to the power 42 to 43 ...


20180823: How Will the Universe End?
 06:45: So in something like 10 to the power of 39 or 10 to the power 40 years, all protons in the observable universe will be gone.


20180411: The Physics of Life (ft. It's Okay to be Smart & PBS Eons!)
 01:24: ... energy being concentrated in your cup of coffee or all the matter in the observable universe being crunched into an infinitely dense point are low ...


20180117: Horizon Radiation
 01:01: ... no information can travel or the cosmological horizon that limits the observable universe. ...


20171025: The Missing Mass Mystery
 00:18: ... PLAYING] Our astronomical surveys have revealed an observable universe full of hundreds of billions of galaxies, each of them with as many ...
 00:41: When we extrapolate observations to the entire observable universe, we find a billion trillion suns worth of mass.


20170810: The OneElectron Universe
 10:59: ... we talked about the controversial evidence that many galaxies in the observable universe are drifting very slightly towards a point beyond the cosmic ...
 11:23: ... assuming it's caused by a gravitational influence beyond the edge of the observable universe, then yeah, it no longer exerts a force on ...


20170802: Dark Flow
 00:08: It may be that much of the matter in the cosmos is drifting due to the ancient gravitational pull of something outside the observable universe.
 05:07: But what if you could measure the effect from hundreds of clusters across the observable universe?
 07:50: ... the dark flow, because that flow seems to affect galaxies across the observable universe, or to two and a half billion light years at least, far beyond the ...
 08:08: ... of a gravitational attraction towards something beyond the edge of the observable universe. ...
 08:32: In the earliest instance of the Big Bang, the observable universe was compressed into a subatomic scale.
 08:58: ... horizon, there exists a region of much more stuff, a different bubble of observable universe with more galaxies, more clusters, more dark ...


20170125: Why Quasars are so Awesome
 06:49: But when viewed from halfway across the observable universe, that is impossibly tiny.


20161012: Black Holes from the Dawn of Time
 02:35: It's thought that these fluctuations originally formed when the entire observable universe was smaller than a single atom.


20160427: What Does Dark Energy Really Do?
 10:16: If positively curved, that would mean a finite but very, very large greater universe with a volume at least 250 times that of our observable universe.
 11:12: And even then, they don't cover the entire observable universe.


20160330: Pulsar Starquakes Make Fast Radio Bursts? + Challenge Winners!
 04:55: That's the mass of all the protons and neutrons in the observable universe.
 05:11: ... the proton, and we get that there are 6 by 10 to the 79 protons in the observable universe, and just as many ...


20160323: How Cosmic Inflation Flattened the Universe
 00:49: The observable universe is impossibly huge.


20160316: Why is the Earth Round and the Milky Way Flat?
 11:42: Our observable universe was a tiny speck in that volume.
 12:16: And at the moment of recombination, when the CMB was emitted, it was emitted by all of the observable universe and beyond at the same time.


20160309: Cosmic Microwave Background Challenge
 00:43: In the process, the distance that the average photon could travel went from not very far to greater than the length of the entire observable universe.
 02:10: ... those blobs evolve into are now 1,100 times further away, giving us an observable universe that's 93 billion light years ...
 03:24: ... need an estimate of the baryonic mass and volume of the observable universe, you'll need the redshift of the CMB, and the Thomson Scattering ...


20160302: What’s Wrong With the Big Bang Theory?
 01:00: And at that point, the entire observable universe was around the size of a grain of sand.
 04:05: And pack all of the galaxies in the entire observable universe into a space 10 to the power of minus 20th of the width of a proton.
 05:40: ... one patch to the next by at most one part in 100,000 across the entire observable universe. ...
 07:16: So those edges shouldn't be in each other's observable universes, not then, not now.
 11:22: ... "universe." Everything that we can see to our cosmic horizon, so the observable universe, was once compacted into something smaller than a grain of sand, and ...


20160224: Why the Big Bang Definitely Happened
 02:36: ... fact, with raw general relativity, we get that the entire observable universe was once compacted into an infinitesimal point, a singularity at time t ...
 07:37: ... early age of 10 to the power minus 32 seconds, when the entire current observable universe was around the size of a grain of sand, give or ...


20160211: LIGO's First Detection of Gravitational Waves!
 03:56: Advanced LIGO can feel the ripples produced by merging black holes through a volume of space equal to about 0.1% of the observable universe.


20151216: The Higgs Mechanism Explained
 03:40: ... the simplest is to say that while the photon can cross the entire observable universe without bumping into a single thing, the electron is never not bumping ...


20151209: How to Build a Black Hole
 00:21: ... whose boundary curvature effectively removes the interior from our observable universe. ...


20151028: Is The Alcubierre Warp Drive Possible?
 05:08: In fact, it would take significantly more negative energy than there is positive mass/energy in the entire observable universe.


20151015: 5 REAL Possibilities for Interstellar Travel
 02:30: And to do that with any liquid rocket fuel, you'd need a fuel tank larger than the observable universe.


20150930: What Happens At The Edge Of The Universe?
 01:04: In a previous episode, we talked about the size of what we call the observable universe.
 03:02: It's a boundary to the observable universe.
 04:40: Move to my left, and my observable universe moves with me.


20150225: How Do You Measure the Size of the Universe?
 00:52: So we're going to focus on the observable universe.
 01:31: And that's the radius of the observable universe.
 02:18: ... can expand at a variable rate, complicate how we measure the size of the observable universe. ...
 05:13: So that's how we know that the observable universe is about 90 billion light years in diameter.
