Mindscape 70 | Katie Mack on How the Universe Will End

[@leftblank6036]

It gives me great comfort that it all comes to a cold dark end

[@hv1461]

Exploring vast topics most profound Awe inspiring intellectual rush Whence a jarring moment of dissonance Sean Carroll’s selling me a toothbrush

[@jekonimus]

hahahaha. Yes. I laughed.

[@gnosisdocumentaries4481]

Bravo.

[@KILLERK260464]

Always look forward to weekly mindscape episodes. Thank you Sean and all your guests. Yeah Yeah Yeah!

[@mikethek5494]

Fascinating. One of Mr. Carroll's most interesting interviews. Suns catch fire, heat death, quantum tunneling, so many ways for the universe to end. On that subject: Arthur C. Clark's (very) short story, 'let there be light' is recommended.

[@allnorweiganwood]

Excellent video made on this by melodysheep. A search for Timelapse of the universe should find it. Very much worth the watch. Again. And again. And again

[@lucasthompson1650]

… or just follow this link to the 29 minute 4K version: kzbin.info/www/bejne/q3WXmq2rebKIh6M (it covers the period from 2019 to EoU)

[@batmanwayne4977]

Great episode. Is there video of the session??? It'd be fun if we could have the video and not just audio

[@pieterrodgers4369]

as far as I know he only does audio..

[@w6wdh]

Katie Mack made a video with the Royal Institution: kzbin.info/www/bejne/rHqrfIh4Zbagd5Y

[@theonetruemorty4078]

Is an infinite prison still a prison? Some recursions are echoes without delay. A loose thread nestled in fibration, Unexpectedly showed me the way.

[@mothernature1755]

- Dr. Romero, Spy Kids 2: Island of Lost Dreams*

[@robertglass1698]

Nice episode. All things I've heard before, but discussed with a little more depth and clarity to add up to a solid outline of the past and future possibilities of the universe.

[@YAS-dn6xn]

Dr. Please, Alan guth on inflation

[@amirshahnazar6674]

Probably the most depressing podcast in the history of podcasts. At the same time it is also very liberating. Thank you Sean and Katie

[@Biskawow]

What about boltzman brain+observer event? (Heat death part of the podcast)

[@rodnewman9934]

We had a good run.

[@lyleman2112]

In a "Big Crunch" scenario, will space itself shrink or will it just be that the stuff gets closer together?

[@origins7298]

I'm not an expert but my guess would be that yes space itself will contract Since space is expanding as the universe expands then when the universe begins Contracting space will contract also I will probably happen on the same scales that it's happening now So it's not like we experienced space expanding here on Earth or in our solar system So I think it will be the same thing when the universe starts Contracting you wouldn't experience a contraction of space at local levels. But as galaxies began moving closer together they're going to bring spaced closer together as well. They use the analogy of a balloon blowing up to show how space is expanding like dots on a balloon are the galaxies. And a balloon itself is space. So pretty sure when the universe starts Contracting it will be like the balloon is Contracting. An Air Force Base along with all the galaxies will begin Contracting and moving together towards a a single point

[@lyleman2112]

@@origins7298 Thanks Chris :D

[@mrloop1530]

In the Bic Crunch scenario the universe will shrink. That includes space itself. Just as space itself is expanding in the Big Bang.

[@lyleman2112]

Thanks!

[@shaun906]

Where there is no matter with the absence of gravity, the space between galaxy's expands (in the visible universe). Its recently come to light our cluster of galaxies are in a very large empty region in galactic web scales. A cold dead universe could be a singularity for a new universe? Size is relative too. A thought experiment: in a universe; if everything was double including physics parameters/ speed of light/mass of particles etc. How would we know?

[@eddieking2976]

I've always said in a hundred years what will it matter. This takes that saying to a whole nother level.🤪

[@lucasthompson1650]

Matter to whom? I don't think we'll see a cure for cancer in my lifetime, but I still donate. I don't think we'll solve our trash/pollution issues in my lifetime, but I still recycle. I've been told by some people that these things I do are things that "only parents really worry about" … but this is not true. For the record, I don't have any kids. 🤔 Well, okay, I'm "pretty sure" I don't have any kids. 😕

[@albertods611]

Loved that podcast. Great minds 👏👏👏👏

[@shaun906]

Due to an expanding universe, Long before the end, very distant future, civilisations will look into the nights sky and see nothing outside there respective galaxies. We are in a unique time.

[@User24x]

Won't elementary particles still be around? So it's not empty space?

[@Smoogems_]

I love this kind of shit before I nod off. Tis' the good shit.

[@RodrigoOshiro]

cool podcast, i think murphy’s law also applies to the universe. it happened once, and here we are... it may end, but then, something else like this may happen again, i guess... im not sure if there is a forever because if this universe happened its probably not unique.

[@PavlosPapageorgiou]

Sean, what boggles me is how cosmologists say this happened so many seconds after the Big Bang. What time reference do we have that stays constant and accurate over that range?

[@origins7298]

Pretty sure that use Atomic nuclei as standard references for time. The decaying of atomic nuclei or something like that But as an observation I think they are referring to from our perspective here on Earth Since matter and energy distorts time and space if there was a living person alive which of course would have been impossible but anyway if there was someone experiencing it their frame of reference Within those moments of expansion would be dramatically different. So I'm pretty sure they're saying looking out at the universe from Earth we know it's been expanding and if you look back at the earliest moments they're giving a temporal Label 2 a modeling of what must have been at certain very early moments. But when you keep going farther back you get to a point where our physics breaks down So again I think any temporal label would be from our perspective we can look at the current expansion rate and we can look at the matter and energy in the universe and we can gauge the rates of expansion But at some point our models and our relationships will break down and there will be no way to give meaning or any temporal relationships So I think any temporal labels would be really looking back in time and they would refer to what must have been after the point where our physics breaks down. So when I say one second after the big bang they mean from our point of view one second after the theoretical Frameworks we have are no longer meaningful.

The Planck Time is a constant, it's always 10^ -43/s (ten to the power of minus forty three of a second). That's the smallest time unit of Physics.

[@rong2912]

Fascinating discussion

[@rumidude]

Really good stuff that I had not read about before. Thanks!

[@connoro842]

Yeah Yeah Yeah!

[@bytefu]

Yeah yeah! Yeahyeahyeahyeah!

[@Einyen]

It is fun she says "if this is true, we can calculate a date (for the end)". But considering the error bars on these measurements, I'm sure the error on that "date" is going to be a few trillion years, at least.

[@jonnybeware6598]

Sean: “…I’m 50/50 on inflation…” Guth: “Get me on your Clodcast!”

[@mothernature1755]

probably one of the best podcasts out there

[@scrambles6669]

Entropy is our destiny

[@mrloop1530]

Wow, you just expressed a deepity

[@eirpcalc]

"The secret of life is enjoying the passage of time" -J.V. Taylor

[@goldenbeers88]

the boson bubble thing terrifies me

[@WeeWeeJumbo]

Oh my gosh it's AstroKatie!

[@FreemanPresson]

Anybody ever refer to Dr. Mack's specialty as Goth physics?

[@frederickj.7702]

AstroKatie... Physics' "Yeah, yeah, yeah" Girl ❗ 😏

[@fishoutofmind4943]

Wouldn't it be more interesting to talk about the potentials of the Webb Telescope?

[@mrloop1530]

Why would one exclude the other?

[@fishoutofmind4943]

@@mrloop1530 Metaphysics is not science.

[@woody7652]

Thanks in advance.

[@Emanresu56]

Wait, so it's possible we could all get incinerated, without us ever knowing it? Did I hear that correctly?

[@lsb2623]

So you WANT to know? And to maybe have a few minutes frying in the agony of your whole life? Pray you get the quick option. Pray you don't see it coming, friend.

[@vincearonson1641]

There are four forces of nature; gravity, the strong nuclear force, the weak nuclear force and electromagnetism. Plus we have dark energy. So why don’t we say there is five forces of nature.

[@mrloop1530]

There are four known fundamental forces. We don't know, what dark energy is. It's really just a placeholder name for effects, we can't account for.

[@DavenH]

Because its effects are upon spacetime curvature, i.e. negative gravity. No need for another force

[@pleaseforgivemyinsanity2801]

Why is the universe ending "bad news"? Who will experience the "bad" if zero people exist? Who will suffer - who will die - if zero people exist? Who would be sad - if zero people existed?

[@MarceloDiCocco]

It also could be thought as: the universe will eventually break by itself, let us not help in it, rather try to make it last the longest.

[@origins7298]

Any physicists reading this? Always thought Sean could really put the measurement problem or measurement effect more front and center in his thinking Isn't it possible that the laws of physics are not consistent at different scales Isn't that why we could have an inability to reconcile quantum physics and general relativity Isn't it possible that when you r talkin about the subatomic scale you're talkin about in a sense different laws of physics I'm pretty sure the many worlds theory is incorrect in the way sean is arguing for it I don't think the universe is branching in to separate universes But from our perspective when different events occur they necessarily entail certain limits on the future of the universe Anyway it's clear that the physics we have does not work at certain energy levels It breaks down during the very earliest stages of the universe and in black holes excetera And couldn't quite possibly be that given the fact that physics or science is a series of relationships, of equations, and attempts to model reality... Isn't it possible that they'll be a fundamental limit to the ability to do this in relationship to things that happened before the laws of physics as we know them, and are immersed in them, occurred... In other words if there are no laws of physics at the beginning of the universe how can you meaningfully describe it from within our universe with laws of physics Anyway I've always thought the time is ripe for a good synthesis of measurement of fact, the uncertainty principle, and the incompleteness theorem It seems like those three ideas are really the core of what makes any scientific assessment Limited And I think it manifests in the simple idea that there will always be a margin of error to all descriptions of reality... And there will always be limits to what we can meaningfully describe Seems like a lot of the conundrums and science really come down to translating different languages and different scales of reality.... I think humans are still kind of bog down from a lot of superstitious magical thinking I mean we're not going to transcend the laws of thermodynamics.... great things are certainly possible with better understanding... but they're going to happen within the abilities of biology and physics....

[@lucasthompson1650]

I'm not a "physicist", but I've studied physics. Re: measurement problem, have you read Sean's books? It is possible that the fundamental forces behave differently at different scales, particularly via small curled up extra dimensions, and experiments continue to be performed to test for these. So far, no luck. Other than general relativity's gravity, quantum mechanics and relativity reconcile just fine. I recommend you dip your toes into Quantum Field Theory. I'm willing to give you the benefit of the doubt regarding Everett's Many Worlds, but you really REALLY need to show some math to convince the physics world, no matter how "pretty sure" you are. 😎 Why don't you think universes are branching? Even if they are, there would be no (easy) way to prove it or detect it, at least not with our current level of understanding. Many Worlds is really more about having a universal wave function than the branching thing. It really seems like your interest in quantum theory and physics has outgrown the tools that are available to you (like thought experiments, metaphors, and geometric representations), yet you have an obviously serious interest in exploring much deeper … Chris, it sounds like it's time to bring some of those math skills up to par. If you are truly interested in this stuff, you won't regret it. Math is the native language of physics, and for a lot of the stuff you're pondering about … math is the only way to step beyond. I don't know where your math education is at right now but regardless of where it is, there are free lectures all over KZbin and the web. If you're not into jumping into vector calculus or tensor mechanics at the moment, check out "quantum field theory" and as far as your query regarding forces behaving differently at different scales and how the laws of physics may have become THE laws of physics, check out any of Nima Arkani-Hamed's public lectures here on KZbin, particularly the ones on "Emergent Spacetime". Again, the math is gonna be a bit heavy, and there will be some string theory and M theory (branes, etc), but Nima is as curious about how the laws of physics behaved at the beginning of the universe as you are, so I'm "pretty sure" you'll find his work interesting. He's done a few general talks about his work as well, a lot lighter on the math, a little heavier on the hand-drawn diagrams to explain concepts … they're all here on KZbin too (I think he's done them at Perimeter and IAS) Always awesome to see someone this interested in physics! Cheers PS. If you've got multiple PhDs and have written papers on conformal field theory - and simply keeping your comment constrained to thought experiments because the rest of us probably suck at math, please feel free to ignore my "hey, maybe try math now!" suggestion and just focus your reply on how awful I am. 😬

[@origins7298]

@@lucasthompson1650 okay so Sean is really fond of this thought experiment called laplace's demon And it always baffled me because laplace's demon flies in the face of a basic understanding of physics I'm sure you're probably familiar with the idea But it's just the idea that if you had infinite computational power and knew every position and particle in the universe that you could computate what would happen at any given time But it's such a nonsensical idea for two reasons. One is that there's no such thing as infinite computational power And second and more importantly is that it is impossible to know the position of every particle in the universe. Because in order to know the position of particles you have to influence those particles by hitting them with some photons of light thus disturbing them And I mean this is basic physics. In order to get the position of particles you have to interact with them and thus create disturbances and fluctuations which can never be known beforehand Anyway I was always really surprised that Sean was fond of mentioning laplace's demon. Because again it is nonsensical it flies in the face of basic physics. It would be analogous to talkin about a square circle So it just made me think that even brilliant physicists sometimes have cognitive biases and so on Any way for now I'm more just into using science to sort of illuminate basic realities about the condition that all people share and you know sort of getting people together around scientific secular values. Maybe at some point I'll investigate the math more but that would definitely take some time and energy. But again I just found out all really interesting because obviously to gain information about any system, about any part of the universe, you have to interact with that part and create effects which can never be completely known.

[@lucasthompson1650]

@chris P First of all, being into using and applying science at a root level, and getting people together through science … you’d be hard pressed to find any reasonably decent human being that would try to dissuade you from that path. Kudos. Laplace’s Demon, yup, I’m familiar. I’m not sure I understand your objections, though. Obviously, in practice we can’t have infinite computational power nor is there a way to step outside of the universe so we can get a single “snapshot” of the state of every field excitation … but that’s not the point of the thought experiment. It’s about IF we had all that, would all future states of the universe be calculable? Some would say no because that snapshot of all the particles cannot provide any information on where virtual particle pairs may spontaneously spring into existence. Others would say, sure, that would work for perfectly predicting the future states of all the particles in the universe as long as that universe had no life, or no intelligent life, or no sentient life, because “free will” would prevent predicting, at the very least, all the particles within the brains of those creatures. Square circles are quite simple to talk about in non-Euclidean higher dimensional spaces. A square circle might also just indicate that a particular cow is sick. That was a great physics joke, ask Lawrence Krauss, srsly.😂 Laplace’s Demon is really a way to hypothesize about how unpredictably “spooky” (Einstein spooky) or deterministically mundane the universe is. That doesn’t mean you’re wrong about the physicists, though. 😎 Every brilliant physicist that I’ve ever heard of has been a human being (Homo sapiens sapiens), so there’s no “sometimes”. All human beings’ brains are susceptible to a number of cognitive biases (between 12 and 25 depending on who you ask). These are part of our DNA, they are built-in, and over the years we have established ways to get around them - and sometimes even benefit from them (“heuristics”). Once you think you’ve gotten past all the cognitive biases and are ready to put forth a scientific hypothesis or argument … you then have to deal with the landmines of critical thinking: the logical fallacies. Over 300 have been identified and documented since the time of the Greeks, but once again, in that time we’ve also come up with techniques to avoid them. In science, the process of peer review takes care of a lot of this for both cognitive and logical errors - this is another reason math is so handy, it turns out that things like Ricci curvature, tensor calculus, and 11 dimensional manifolds in anti-deSitter space … are the same in Japan, France, Russia, India, etc… so getting a math or physics paper widely peer reviewed can be a lot easier than a paper on linguistics or psychology. 🤓 That said, it’s pretty rare for a well known, well published, respected physicist to actually behave as if constrained by some cognitive bias - but “pretty rare” isn’t “never”. Case in point: Cold fusion. For a physics hypothesis, it’s often helpful to try it out in hypothetical or nonsensical environments such as: a universe where you can hit “pause”, measure everything, and hit “play” again. This isn’t really any different than testing an equation to make sure it works in 1 dimension before moving on to 3D space or 4D spacetime. Most of the theoretical work on the Holographic Principle was done using toy models of black holes that lived in anti-deSitter space (eg. A perfect test sandbox) rather than a mostly flat 4D Minkowski spacetime (eg. Our universe). Why? For one, the math is WAY easier. I know I said math was the language of physics but that doesn’t mean it has to be hard. Do you know what the speed of light is? One. As in the number, 1. Why? Take a look at a physics textbook and count the number of times you see the variable ‘c’ in those equations … uh huh, that’s why. C is 1, so C squared is 1. C cubed? Still 1. 1 what? 1 unit of c. Usually km/year or m/s, but you plunk that in at the end when you’re done since it’s just a scalar multiplication step. 🤓

[@origins7298]

@@lucasthompson1650 I'll read your reply in more detail but I got to jump right in because you're doing the exact same thing that Sean Carroll is doing In other words laplace's demon is not a meaningful thought experiment, because it's conjecturing things that are physically impossible Okay maybe Square Circle wasn't the best analogy But again there's no way to take snapshots of the universe because to gain information about any system you have to effect that system and in the process you just create a larger system So any intelligence that was outside the universe and was trying to take a snapshot of our universe would have to interact with our universe in some way to get that snapshot I think the problem is that our language gives us abstract ways of thinking which do not do justice to the reality of the Universe we find ourselves in Again there's no way to take a snapshot of the universe because in order to get any knowledge of a system you have to effect that system This is why I said Sean does not seem to take the measurement problem for the Deep implications it presents The measurement problem in physics touches upon the deepest implications because it tells us the limits of knowledge and meaning The measurement problem in physics tells us that the words deterministic and randomness will never have any precise meaning. All you can do is say what has been proven true within a certain margin of error. And there will always be a margin of error So the whole beginnings of the thought experiment about IF you could know all the positions of the matter and energy in the universe seems to trample over one of the most profound details about our universe. The fact is you can never know the positions of all the matter and energy. It'll be like saying if you could know the position and momentum of an electron both to 100% certainty, well you just can't, it's a physical impossibility Anyway I always thought this fact clears up the double slit experiment. Because clearly if you're interacting with the photons at some point in the experiment then obviously that interaction should have a noticeable effect. But I think other s who understand all of this much better than I do have already put forth such theories...

[@lucasthompson1650]

@chris P Okay, but Alice and Bob will never own spaceships that can travel at light speed, nor will Bob ever live on Alpha Centauri and be able to communicate with Alice back on Earth instantaneously to discuss if the electron he found in the box was spin up or spin down. Schrödinger never had, and therefore will never have, a cat. You and I will never have access to an infinite number of chimps typing on an infinite number of typewriters, but that doesn't change the fact that one of those chimps will type nothing but exact, case-sensitive, copies of all the published works of Shakespeare, and that another one will do the same, but type them backwards. The measurement problem is a problem, and using the word "never" when describing a problem in science … well, that's "never" a wise idea, historically. 😎 We'll never be able to snapshot the universe or access infinite computational ability … but these are very easy things to conceive in our imagination. These are easier concepts to conceive than faster-than-light travel, and even science fiction writers can manage that one. Heh. 🖖🏼

[@leonenriquez5031]

Great podcast. Glad they mentioned Penrose's model. Can't help notice: Scientists surely seem very impressed with themselves.

[@NoActuallyGo-KCUF-Yourself]

I think it is more like scientists are very impressed with Science, and not necessarily any particular scientists.

[@dmitryshusterman9494]

Obviously, the universe will end when I die

[@nitroninja2170]

Here's more Katie! kzbin.info/www/bejne/r4XTaWZjhNd3nrc

[@origins7298]

For the people that think it's gloomy... You are talking about trillions and trillions of years of potential future for life... It's an unimaginable time scale... And while I think it's good to talk about but it's almost a given that people will think it's gloom and doom when it's almost an infinite amount of time.. it would be like the smallest Speck of matter saying it's the same thing to be a piece of dust and a living person because we both follow the laws of physics. Yeah but the scales of complexity are slightly different

[@jonnybeware6598]

Nice segue into toothbrush theory, Sean. Exactly why I listen to you! 😏 (jk :)

[@danielssandu5578]

Consciousness is an immense set of complex algorithms, in a neural network, able to vision the world and layers of the world, able to like or dislike visions, and also able to elaborate random algorithms, which may or not be useful for better understanding of the world and/or surviving, as individual or as part of a community.

[@DavenH]

Doesn't sound like consciousness to me. That sounds like the hardware.

[@hmdshokri]

Freeman Dyson would be an amazing guest, but I'm not sure he could talk for an hour considering he is a century old.

[@hmdshokri]

@@mrnarason according to Dyson,he was not sure global warming is bad, so they change it to "climate change" that is bad for sure.

[@madderhat5852]

SPOILERS

[@juanaq]

in contrast with such a bunch of gloomy perspectives, the podcast was full of yeah yeah yeahs.

[@NoActuallyGo-KCUF-Yourself]

I clocked them at an average of 4 yeahs per minute.

[@joshh6376]

yea...yea... yea yea yea yea yea

[@kevinfairweather3661]

watched

[@733eel]

nothing matters apart from the time you spend with your loved ones

[@Thencamethechaos]

Yeah. Yeah yeah yeah.

[@EmmaSunshineUnicorn]

I can’t stand the way she mumbles through “cosmological constant”

[@unleashedvideos1105]

First?

[@vladimirs3272]

Treasure your fleeting achievement while entropy inevitably increases and the universe cools down