Episode 51: Anthony Aguirre on Cosmology, Zen, Entropy, and Information
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- เผยแพร่เมื่อ 16 มิ.ย. 2019
- Blog post with audio player, show notes, and transcript: www.preposterousuniverse.com/...
Patreon: / seanmcarroll
Cosmologists have a standard set of puzzles they think about: the nature of dark matter and dark energy, whether there was a period of inflation, the evolution of structure, and so on. But there are also even deeper questions, having to do with why there is a universe at all, and why the early universe had low entropy, that most working cosmologists don’t address. Today’s guest, Anthony Aguirre, is an exception. We talk about these deep issues, and how tackling them might lead to a very different way of thinking about our universe. At the end there’s an entertaining detour into AI and existential risk.
Anthony Aguirre received his Ph.D. in Astronomy from Harvard University. He is currently associate professor of physics at the University of California, Santa Cruz, where his research involves cosmology, inflation, and fundamental questions in physics. His new book, Cosmological Koans, is an exploration of the principles of contemporary cosmology illustrated with short stories in the style of Zen Buddhism. He is the co-founder of the Foundational Questions Institute, the Future of Life Institute, and the prediction platform Metaculus. - วิทยาศาสตร์และเทคโนโลยี
When Aguirre states “it’s on record” that he thinks dark matter will be several different things...then Sean says “ohhh bold” so passive aggressive, I love it!
This was a fabulous podcast. Prof. Carroll is such a good communicator and ambassador of these high level cosmology conversations.
I would welcome an entire podcast on the discussion about what exactly is meant by information. Every time I hear it discussed I feel I like I both understand it better and yet still end up with more questions.
Me too and feel even less informed on what exactly is meant by "energy". As best I can tell, nobody knows what it is exactly.
@@seriouskaraoke879 There's an inherent problem with trying to describe fundamental concepts because by definition they are almost indescribable in terms of other things. Inevitably you have to either resort to some useful but ultimately inaccurate metaphor or settle for an operational definition. Studying the mathematics of these things in detail is the only real way to get a precise grasp on what fundamental quantities like information or energy "are."
Robert Glass yes it’s a very difficult concept and I believe, unironically, that there is a lot of uncertainty around it. A major part of my understanding is the link between entropy and messages we send to one another. Entropy is a measure, in a sense, of what way something is in relation to all the ways it could be.
Our messages are similar in that nature, so many different ways I could have written this message, yet I chose these letters. And here, with symbolic communication, we can assign a measure to the arrangement, with a unit called the Bit.
Did that help at all?
@@erictko85 I like your description of information. I think I meant that the interesting part was how it is fundamental to our universe and how viewing it as fundamental affects the other physical theories... or even more metaphysical notions.
@@robertglass1698 Agreed. I hope we can hear a podcast on that as well!
I just love listening to Sean Carroll, thank you for sharing your wisdom.
The world most certainly is paradoxical. Sheesh! And we all - most definitely including scientists and philosophers - suffer from the tyranny of everyday language. The purpose of a zen koan is to precipitate a non-verbal intuitive experience - perhaps, at one end of the spectrum of possibilities, even a dramatic earth-shaking satori experience. And, at the other, perhaps a quiet and healing flash of gentle understanding. In either case, a satori experience, whether more or less dramatic, has more in common with a sneeze than a thought. Once it actually starts, you cannot stop it. The trick is to get your thinking mind out of the way so it can start.
"I can personally certify that Anthony Aguirre is a world-class physicist" - Max Tegmark, world-class physicist
I have been waiting for this TOPIC FOR A LONG TIME! I WILL BE LISTENING TO THIS 100X THX SEAN LOVE U
good topic. can listen to it all day. Thank you Dr. Sean Carroll.
Best. TH-cam channel. Ever.
Nerdy Rodent almost
Incredible stuff. Both are brilliant communicators and undeniably extremely accomplished cosmologists.
It's always exciting when a new mindscape podcast comes out. I must say I'd immediately notice in this podcast an increase in sound quality. Sounds like Sean has used some nice vocal compression making speech much more clear in noisy situations as I am forced to listen in. Thanks so much continue with the podcast ...
This is a great episode and Mr. Aguirre tells very interesting things!
Whew-good one! Tks guys
"...the growth of entropy and order is driving everything we care about..." was the big statement to me. So, if entropy or order are the nouns, what is the verb that describes that which changes the states of entropy. Could it be considered a force? Sounds like starting a coaster ride at the peak without knowing what lifted you there.
To my way of thinking, since there is no "now", entropy/change/order are all a part of the same thing...or entropy/order are completely separate, and cannot change into each other...but I am high on acid right now soo...
I love Sean Carroll!
38:35 Stop it! The universe didn't "start" with low entropy. The combinatorial laws of the universe imply that its states are ordered by increasing entropy and that we experience that as time and say that it "started" at low entropy. But it could not be arranged otherwise. Both definitions of entropy follow from information conservation. I should make a longer explanation...
Sweet! This is going to be good! BTW, where and when can we ask you questions???
I just love the cat that occasionally meows in
It's Shroedinger's cat. It's probably not there. Or is it?
Entropy in the heat death is high and the universe is even. The universe in the big bang is also even, but entropy is considered low, how?
This is amazing
When you pour water from an empty jug, was the water in the jug in the first place??
Mr. Carroll, I'm certainly far from understanding the Quantum Problem. I'm curious, would Universal expansion represented as an effect of dark energy correlate with the idea of branching universes in the many worlds concept? Am I "off in the woods" on this? I like the idea that the Universe is expanding due to quantum entanglement and branching.
Does entropy depend on space. I have a hunch it should explain why we think the early universe must have had a low entropy state, while it really didn't.
Hey Sean, if I may a quick question? Some put out the possibility of infinite copies of our earth in an infinite Universe...I find it troubling and probably unlikely. If we have let’s say infinite amount of unique prime numbers in the infinite set of numbers, can’t there be infinite amount of unique civilizations in an infinite Universe?
While listening, my thinking got trapped on that idea of an infinite source of order.
That sounds suspiciously religious or philosophic.
I find there’s always a duality, and I’m not sure if we can make it go away, or even want it to go away:
There is the laws, and then there is the starting condition.
When you don’t like the starting condition to be so specific, be it anthropic or isomorphic or low entropy boundary condition, you invent a new law or process that produced it: multiverse, cosmic inflation, infinite source of order. Even the concept of creation itself is about the process of getting initial conditions from a process which creates / distinguishes something from nothing - does not matter what specific religion or culture you look at: they all have some sort of creation myth / story. Even if the net energy of the universe is zero, you still have to have a law that allows it / gives it meaning.
Information is always about something. In order to have information, it needs to be about a state of matter / energy / spin whatever - in order to make sense of “information” we have to specify what we are talking about - there has to be a quality that does not go away, even if its value changes. Even if the fields sit at zero, there are still fields. Even at the heat death of the universe we’d still expect random fluctuation (- thus Boltzmann brain e.g.), as there is still the rules and that vacuum stuff / spacetime which it applies to. The only way to make the duality vanish, is to make the rules / laws vanish: then something and nothing become indistinguishable / the same.
I think we could not even have language without this duality: the “aboutness” of thought and language reflects (- if not “creates”) this duality.
I think we always end up with Wittgenstein and Touring, call it information theory, mathematics or language: this is the thing we need to understand, while being also the method by which we understand it, which again makes it circular. We will inevitably end with some axioms that can not be proven within the same system (Goedel?). We can’t put the ghost in the machine: it has to have been there from the beginning.
There is the things we can speak of, and the rest is silence. - Which means that the really intelligent people start occupying themselves with the more mundane and trivial stuff, and only the fools continue with meta-physics and philosophy and religion beyond the regimes of their applicability - there is always a border to our understanding, no matter how far we push it.
Sean Carroll’s occasional laughter always makes me smile. What a terrific host.
1:15:37 that's the simulation hypothesis, not the simulation argument. If it turns out it's not possible to run a lot of detailed simulations because of insufficient computational power, that's compatible with the simulation argument www.simulation-argument.com/simulation.pdf
around 40:00, what was there at the beginning? Information or matter?
Matter didn't come from nothing. The equations of physics, including the equations that describe the big bang, describe something, something physical; that's why it's called physics. The matter we see today comes from the (is?) matter at the big bang.
Where did the information come from? Information? Can it come from nothing? If information isn't informative, that is it tells you about nothing, is it really information? The information was present at the big bang.
The big question is, how did it get there?
my go-to sleepcast
Hey you started putting your playlist in reverse order. Nice.
@Kelp Farming So you don't have to scroll far to see new content. It becomes a pain in the ass after a while, especially when the playlist gets long.
I'm a simple man, I see a new episode I click like.
Well that's an hour and a half of my life gone. Thanks for the show Sean i love your work on philosophy.
Am I missing something? Anthony keeps talking about Entropy as if it were something that exists, regardless of whether or not there are intelligent beings in the universe. I thought that was entropy was a measure, a description of the uncertainty one has about which particular microstate is obtaining which is leading to the observable macrostate in question. Here entropy is a description of uncertainty by an intelligent observer, not a property of the thing itself, or am I mistaken?
2nd Law of Thermodynamics refers to closed (or isolated) systems. Can one really call our universe a closed or isolated system? Until we know exactly how we got all this from nothing, I don't think we can. That, coupled with the Many Universes interpretation of QT.
Just wondering... Can you get along with Lawrence Crauss?
Why is that pow entropy means tramendously high information? Isnt it suppose to be low information?
@29:06 Nice Meow 🐈🐱 :)
00:17 take my like sir
Surely if we learn more about the ant we decrease our antropy.
... Chickens on strike = Hentropy.
So would we also decrease our uncletropy?
Furthermore, if we learn more about the ant then antropy decreases, and dwell in antidesitter space.
How do you pour tea from an empty cup??
By concentrating on how it happens, even if the tea nor the cup is there.
Or, you're just open to what comes to happen.
@@jartsan8477 There is no spoon.
Question if space is expanding, does that mean the space in atoms is getting bigger too? So are WE getting bigger?
No. Local space does not expand. And that includes atoms in our bodies. Even galaxies do not expand. See here:
www.forbes.com/sites/startswithabang/2017/07/28/most-things-dont-actually-expand-in-an-expanding-universe/#392c93c43d74
If I pile a heap of sand, does the heap have low entropy because it is packed together? NO!
Shades of Douglas Hofstadter's Godel Escher Bach.
Sean has been a huge inspiration to me! I've followed his career for a long time now, and while I disagree on several points (check out my channel to see why), I do enjoy his modesty and humility when it comes discussing these types of complex topics.
Zen is my zen.
Meow @ 29:05
With such a long view ... trillions of years left for humanity, to solve every cosmological mystery we encounter ... Wouldn't it make ultimate sense, first to solve humanity's tendency to balance on the edge of self-extinction?
Shouldn't long-term survival (stability) be priority #1?
I mean ... human civilizations have *provably* been doomed to collapse, with great loss of knowledge following ... believing our instance should be any different in that respect, from all that came before, seems like wishful thinking ... right?
@@animistchannel2983 ... What a lovely fantasy ... have you heard of the Antikythera mechanism?
Do *you* know how to create a smartphone? ... or any of the infrastructure needed for a smartphone to work?
Well, most people don't ... and I bet the same could be said for the computational knowledge, that went into the Antikythera mechanism.
Right?
I still contest, that we are only a couple of bad decisions, and perhaps a natural disaster away, from a total civilizational 'reset'.
@@animistchannel2983 ... A die hard optimist ... I think that frame of mind, might be quite dangerous.
Perhaps you are right ... But doubting it anyway, might yield some caution, and could let us contemplate the 'what ifs'.
For instance, I'm not that worried about 'the red button', altho it still poses a grave danger. But how about individual billionaires developing/controlling technology they really don't understand long-term. Genetic manipulation and General AI for instance? ... And leading politicians being without any kind of savvy ... An army of drones and killer-robots sounds mighty cheap in running costs.
All-in-all, the cross-roads is right beneath our feet today, and you optimists seem utterly unaware, or just completely uninterested. You seem to have no time for philosophy. Even tho, humanity could have trillions of years in front of us.
Yes everybody seems to be in a bloody hurry ... But could such sense of hurry, be the very ting, that trips us up?
I'm thinking Fermi Paradox 'Great Filters' ... Hubris might be it.
@@animistchannel2983
"If you want to learn to live with SAI, you need to stop trying to become the perfect master, and start learning to be a better brother."
... That rings very true ... hence my fear ... Humanity have squarely handed the power of creation, to billionaires and mega-corporations ... who, in my mind, are psychotically driven to produce a poorly studied likely AI-catastrophe. All in the name of competition for time, and the mighty dollar.
If AI works out positively for life on this planet, it will clearly be contributable to lucky coincidence, not wisdom ... Not wisdom!
Anyway, writing off such self-made existential threats, to intangible natural master-law, like you do, seems to be the very reason such threats emerge in the first place ... a simple lack of perspective, understanding and will to harness and/or prevent them ... Full speed ahead seems to be the mantra, time is money, and the Fermi Paradox may be the result.
What a terrible game of chance to play, when you really don't have to. What a waste :/
That is the first time I hear that it is perfectly possible to have a universe out of nothing! :D EXPLAIN! :D:D
I dont think your site is working :/
It would be great if you had on aron wall. He's a Christian cosmologist who has responded to your post William lane Craigde debate reflections/thoughts. Would be awesome to have two cosmologists with different perspectives having a scientific discussion about the universe and nature of reality.
Lots of rather confusing statements about entropy.
Is there any other "objective" ( that does not depend on coarse graining) notion of entropy that increases with time in our universe besides the entropy that is associated with causal horizons?
Buddhist Cosmology.. I like it 🙂
Relativity of simultaneity has always weirded me out.
That is likely because how it is usually described, they tell you that there is no universal "now." That is a mind-screwer.
During the "Are we in a Simulation" discussion, there appears to be an assumption that the "outer" universe has the same properties as ours. I don't find this convincing. I suggest that we cannot say anything about the outer universe. As a game player, and dabbling game developer, The outer world - ours - is very much more complex than the inner world - by design - so that it is easy to simulate the inner world - the game. Also, as game developers, we "Cheat" using Level of Detail and other Simulations to fool the NPCs and Players about their environment. If we grant these motivations to the "Outer" developers as well, then the view through the LHC will only be as detailed as needed to convince us, and the rest of the world will be much simpler - only complex enough to fool us into thinking that the whole world is as the LHC sees it. And same for Hubble and Radio Telescopes, etc etc. That's what we do to develop games. Why not our Outer folks?
I wonder why this podcast is called MINDscape :P
Because it is trying to help you escape your mind and live like a free floating bodyless Koan in the non-baryonic multiverse.
@@RareshVladBunea Well to be fair, not all of his podcasts are this good. Not to downplay his normal podcasts at all, simply meaning to elevate this one to its proper "godly" status.
in another world , we don't build houses and still carve out caves .
Is that a "No" then on a podcast with Eric Weinstein?
How would QM behave if you posit an omniscient field? Many Worlds disappear sorry
Dark Matter is simply unaccounted for gravity. General Relativity states that gravity is the consequence of the curvature of spacetime. Is it possible that the structure of spacetime itself could be warped without the presence of mass? Spacetime has been shown to react like a fabric by warping, twisting, and propagating independently of mass, and all have been proven with observations from gravitational lensing, frame dragging, and now gravitational waves! Fabrics can be stretched, pressured, and/or heated to the point of causing a deformation. All of these conditions were extreme during inflation, so it is plausible that the “fabric” of spacetime analog could extend having its elastic property have hit a yield point.
Therefore, if gravity is the consequence of the warping of spacetime, and fabrics can be permanently overstretched, then those empty warped geodesics would create gravitational wells independent of mass. My hypothesis of DM is subatomic black hole imprints of the quantum fluctuations that popped in at the moment of inflation. These would be clouds of quantum sized floating fixed geodesics, so they couldn’t expand or evaporate. Perhaps nothing has been detected because there is nothing to detect, and GR wouldn’t require modification of mass interactions because DM would just be an extension of how space-time behaves at extreme conditions. No WIMPS, no MOND, no parallel universes, just empty spacetime deformations that produce gravitational wells to help jump start galaxy accretion processes.
@@lt4954 I agree it is some type of field. Not sure what mechanism makes spacetime warp around mass. I wish Einstein completed that part of gravity. Hopefully they find the TOE before I die. I would love to know...
@@animistchannel2983 Yes, the fact that DM moves is an issue, but spacetime is dynamic and growing. My best analogy is like ice can float on top of water, maybe the DM is frozen parts of spactime that can float around yet still hold its shape. There is so little known about spacetime...
@@animistchannel2983 Thanks, yes I know his channel. I also know Fragomatik's channel. I used him for my aritficial gravity concept for my NASA work. www.nasa.gov/directorates/spacetech/niac/2017_Phase_I_Phase_II/Turbolift/
Give feedback to your guest. Having listened to 50 podcast, this one stands out as being very hard to understand. I listened to the words but I got almost nothing out of this. I continued to listen with high attention, noting the strange phenomenon... the words kept flying but it was as if phrases and sentences were correct, but beyond that it was intentional nonsense. *Then* near the end, all of a sudden there are a few sentences where you can understand what he's saying. It seemed to come out of nowhere. It suggests the guy is capable of saying something that a person could understand.
During this long spiel of stuff that was being conveyed terribly, it occurred to me that Sean could deliver the same information in a way that would be easy to follow. I would far rather hear Sean explaining what the guy was trying to say.
Someone give this guy a lecture on pacing. You can't just fire machine gun full-auto words at people for an hour with no pauses and accomplish something. A person would have to be either extremely nervous or not self-aware to do this.
I'll bet the guy can't listen to recordings of himself because the experience is so painful. Ya, and that's how we feel also.
Sean, please help this person. You are great at this pacing of speech, and he is horrible.
Cheers!
"Right Now Does Not Exist." 7:57 Well, then, hmm . . . How about half past seven? Does that work for you? - j q t -
It amazes me how beings that have never been beyond our own moon can claim to know so much about the observable universe. It was like listening to a court case with two defence lawyers and no prosecution attorney. I’m not saying you’re wrong. I’m not convinced by your interpretations of the evidence but either way it would be nice if you said that this is what you believe is the facts with the evidence and science with have at our disposal at the moment and not talk like you were present at events that occurred billions of years ago.
Maybe they were present...
Could someone coach the guest out of saying “sort of”, “kind of” or “you know” 20 times a minute. Seems like an interesting person but I can’t I unhear his endless repeating of these terms virtually every sentence!
I would suggest that you try being less shallow? I mean, what you're describing sounds like more of a "you problem".
1:25:00 A.I.and human level intelligence. Think about Aguirre's take on simulating and what that would take to simulate a bacteria. It's going to take a lot more to simulate a human. If your going to simulate human intelligence your going to need to simulate the whole human.
Itelligence isn't an ordinal scale, it's a bunch of categories of skills, not a series of levels. Sure computers, A.I, are better than humans at a number of tasks but that doesn't make them more than human. The nature of a thing comes from it's physical nature. Humans and computing devices are very different things, we shouldn't expect them to the have the same properties. Caring, feelings purpose are properties of human type things not of silicone type thing. The states of physical systems that can be modeled by math but the numbers and equations only represent the thing, they aren't adrenaline and a racing heart beat. A.I. will be powerful but it won't be human unless isn't built of human meat. A.I will be a powerful tool and there's always dangers when humans start playing with powerful things. A.I. won't have human emotions, it won't care if you turn it off or leave it on. Besides, emotional A.I. might be a fun like having a dog, but no sane person would give an emotional A.I. control when reliability or safety are a concern.
Grasshopper, I will show you that your lie was, indeed, the truth, trust me.
Wax on, wax off, wax on... Mr. Myiagi
I know I have a question about entropy and its relationship to consciousness, forget the universe, but I cannot articulate it, nor can I describe the relevant koan.