Mindscape Ask Me Anything, Sean Carroll | May 2020, Part One
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- เผยแพร่เมื่อ 31 พ.ค. 2024
- This is the monthly Ask Me Anything episode for the Mindscape podcast. It is offered courtesy of Patreon supporters of the podcast, who are invited to ask questions every month. Here you can listen to my answers; if you'd like to ask questions, please support on Patreon.
This month the episode ran too long for Patreon, so it was broken up into two parts; this is Part One.
Details at web site: www.preposterousuniverse.com/...
Patreon: / seanmcarroll
Mindscape playlist: • Mindscape Podcast - วิทยาศาสตร์และเทคโนโลยี
Thank you Sean for making the quarantine and working from home more bearable.
Thanks for the AMA Sean! I'm just a layman but derive the best understanding of theoretical physics from your explanations since Feynman.
I think almost everyone is the same way)
Thankyou your content has really helped me detract me at this really difficult time x
thank you
I couldn't take a Sean Carroll class- his voice is so smooth I would fall asleep too much. But he knows his shit!
The question asking regarding Roger Penrose, quantum mechanics, consciousness. Rudy you already knew Sean would say no. Lol
David Deutsch please!
43:17 Sean's response to Riverside's point seems to be sort of a cop out. Perhaps in most cases Sean's point that unlikely events with a bad outcome could be cancelled out by ones with good outcomes is correct. But I think we can still come up with scenarios where this is not the case. For example, we can design a setup where pressing a button will definitely shoot out a bullet at someone in one out of a trillion branches of the wavefunction but have no effect (at least "directly" and immediately) in all others. Suppose I'm offered $10 to press that button, is it moral to do so? According to classical interpretations of QM, we don't have to worry about such tiny probabilities. But according to MW it is a definite murder. Sean might still argue that we don't know what might happen "indirectly," especially in the distant future, by pressing the non-functional button or by receiving the $10, but it doesn't seem plausible to justify a definite murder based on unknown indirect effects. This refutes Sean's idea that MW has no effect on morality, at least in principle. We can also perhaps come up with more realistic scenarios where the bad outcome is extremely unlikely but still clearly more likely than any counteracting good outcomes.
Thought experiment, if you had a physical circuit that ran from point (a) out to point (b) and returned. If we considered point (b) begins to rotate around point (a). As the velocity of (b) becomes a percentage of the speed of light, does the resistance of the circuit at point (a) incresed due to time dialation ? I hope this is not a stupid question.
no
Thanks, Dr. Carroll.
The question concerning the bending of space due to gravity forcing an small object to move toward the object (planet, sun, etc.) causing that bending seems to have been about why that bending of space makes the small object move in that manner, rather than just sit where it is and only move along the curve when subject to some other force on it. That is, why does bending space in one direction -- at "right angles" to the plane of motion in the conventional 2D space image of a weight on a stretched elastic surface analogy -- also push the small object in another direction -- toward that large gravity-producing weight. Why does an ASYMMETRY in the space-time region due to the gravity-producing object cause an effective flow of that space-time into the gravity-producing object, pulling the small object along with it? Just because you are sitting on a ramp where movement is easier down the ramp rather than up the ramp does not intrinsically mean that if you are not pushed that you will move in either way by yourself. Something about the asymmetry itself is causing the force pushing the small object. What could this be? The force of gravity is extremely small compared to the masses causing it (except at very, very short distances usually not considered except in a black-hole-type situation), so the cause of this inward force has to be a small effect, too. It seems to me that this inward "force" is not due to the bending of the space dimensions, but the change in the RATE OF TIME as measured by two clocks, one at the center of mass of the small object and one at the center of mass of the gravity-producing object -- in effect the tidal effect in time dilation between those two clocks causes the net force toward the region of tighter bending/slower clock rate. That is, if you put a brake -- slowed time to perform any action, including the intrinsic energy inside everything due to Quantum Mechanics and the waveform portion of their existence -- on one side of a moving car by only connecting the brakes on one side, when you push your brake pedal down, you will slew toward the side with the brake (slowed clocks) as the other side tries to keep going straight ahead. So, even if you are originally not moving at all in a "classical" physics manner near the gravity-producing object, your small object's intrinsic E = m x c-squared vibration energy (and its equivalent for mass-less things moving a speed c) will cause it to slew like that braked car toward the gravity-producing object, no matter what you do. Thus, it is impossible to "just sit still" at any point in that bent space around the gravity-producing object as long as you exist as some distinct detectable (energy-filled) object in our space-time. I do not think that I am completely handling the cause of the pull of gravity, but I think that the asymmetry effects on the structure of space-time itself are the cause of the attractive force.
Sean. Your talents are universally appreciated and exponentially loved. Keep up the multiuniversal expansion of wisdom. By the way are there other locations where a bing bang has and will occur given that scientists think our current universe was created by a single bing bang? Why wouldnt billions of big bangs been created in an infinite universe?
some bang has to be first even in infinity, maybe each bang is infinitely spaced... oooh spooky shit this eternity lark
Most free will skeptics do not lump together the concept of free will with the concepts you lumped it in with like volition or choices. We believe in choices, just not that you chose to be the one that would tend to make that choice. Long time follower, so I have heard your explanations regarding your position here, but you don't seem to get our position. Our word preference is such that when you say that you basically have the same ontology that we do (determinism, or determinism + quantum dice rolls = no more free than determinism) but that you prefer to have an emotional carrot or stick from using the expression, "free will," we basically think that, deep down, you just want to fit in with the pre-scientific smelly masses similarly to people who believe in, "God," but really only believe in love or believe that life has some mystical shimmer sometimes. Not trying to be a jerk; I just really don't think you've grokked what we are saying. Love the podcast, at any rate!
Good Tube
22:58 Wait, so the fact that we aren't LaPlace's Demon means that the idea isn't true. Free will could be false even if I can't predict the outcomes, no? I don't know what the computer will do is quite a bit different from the computer will freely do whatever it wants.
I’m quite surprised that you never had a chat with Don Hoffman. Is there any particular reason?
He was good in Rain man
Q: How did the homogenous and presumably isotropic universe (after the big bang) become lumpy and non-homogenous for galaxies to form?
Quantum fluctuations
Q: "Can you comment on Eric Weinstein's theory of Geometric Unity?"
Me: YESS
Sean: "Nope"
Me: NOOO
I appreciate Mitch’s effort
I've listened to EW and can't yet tell if he's on to something or if it's just word salad.
Ashwin Ramesh Weinstein hasn’t publiced a paper on the topic. Until then he will not be taken seriously.
The answer is the same Sean gave on Wolfram’s paper. There are too many good papers written by good faith scientists to pay attention to grandiose claims made by science amateurs. If something comes out of it, someone in the science community will say so but it is not looking likely with every passing day.
Eduard Stancu How did you come to that conclusion?
Thank you for the videos. Is there a fundamental reason for the prevalence of wave mechanics in nature?
Come on man. Cut the guy some slack. Sean, and people like him, are busting their arses on the 'WHAT' question, with maybe a little of the 'HOW'. But the 'WHY'?!! However kudos for asking a physicist rather than a religious scholar.
@@primus4cameron It is not a theological question. Can anyone deny that wave mechanics are prevalent? I am simply asking why.
I hear ya. But hey, did I say it was a theological question? No I did not, 'cause it ain't! And no one, with any authority can deny that wave mechanics are fundamentally important, least of all Sean Carroll who, if I understand his position on this stuff correctly, argues that the quantum state is THE most fundamental thing we know of! That's to say wave mechanics aren't just prevalent, they're the only way to describe the quantum state from which every thing else (even spacetime itself as Carroll argues) became emergent. But NOBODY knows "WHY" the universe is the way it is. Chill out and read his latest two books in which he explores your query in some detail - way more than could meaningfully be addressed in a Q&A. Cheers
Yay! 🙃
I feel like if you were floating around in Intergalactic space and turned off any sort of local light pollution, your eyes would likely adapt somewhat and you'd notice at least the closest galaxies without too much difficulty as there would be no big bright local stars in the way acting as "light pollution"
Carroll [as he says himself] hasn't done the calculation - I think J. A. Wheeler is right that we'd see nothing with the unaided eye from almost everywhere within a typical galactic void. A void is approx 100s of millions of light years wide & nothing is bright enough [even a galaxy] to tickle our photoreceptors at ranges beyond single digit millions of light years - our eyes are very poor instruments & there would not be enough photons hitting the eye to form a picture. We'd also be getting interference by 'seeing' cosmic ray ghosts as high energy particles burrow through our receptors - these cosmic rays & their products greatly effect human vision even in LEO - we have no idea about magnetic fields & associated ionised particles in the voids, but it could be a big influence or none or in between...
@@nightjarflying Owls feeling smug
@@PazLeBon Yes & spacemice must fear for their lives in the voids!
Question: Do all physical influences at the fundamental level spread always at the speed of light only?
sound is a physical influence
@@PazLeBon But sound is not fundamental. Sound is a high level (compound) movement of (already) particles (molecules, atoms, ...).
@@miroru1 Fair enough. So snt it still made of fundamentals that are constrained in this form?
@@PazLeBon But what are fundamental particles made of and how fast it moves when the particle is at rest?
@@miroru1 maybe its always dictated by the other influences.
In at least one Native American language, distance in time and distance in space are considered to be the same thing.
seems logical to me
If we assume hawking was right and this universe is finite, space and time originated with the event at inflation, there is no space and time outside the bubble that is our universe, what happens at the edge of the particle horizon if you reach it or try to cross it?
I assume whatever edge there could be is accelerating away from the next bit of space at the speed of light and therefore would never be in the light cone of any particle. Therefore there is no edge that anything could ever cross.
@@jamesa4566 has to expand into something or nothing tho
Hertog and Hawking did NOT predict the "universe is finite" - they predicted that the universe that emerges from eternal inflation on the PAST BOUNDARY is finite & far simpler than the infinite fractal structure predicted by the old theory of eternal inflation. Also they did not predict there is no multiverse - Hawking: “We are not down to a single, unique universe, but our findings imply a significant reduction of the multiverse, to a much smaller range of possible universes” Reference: S.W. Hawking & Thomas Hertog. ‘A Smooth Exit from Eternal Inflation?’’ Journal of High-Energy Physics (2018). DOI: 10.1007/JHEP04(2018)147
@@jamesa4566 We have a warp drive that can go many times the speed of light. The timespace boundary is less than 1 light year away we aim 90 degrees to traverse it, what happens when we reach the particle horizon?
@@captainzappbrannagan That question makes no sense - everybody has their own particle horizon that depends on their location & their velocity - it's like asking if you can reach the horizon on Earth [the horizon due to the Earth's surface being a sphere] by travelling very fast towards it in a car ~ the horizon stays stubbornly unreachable no matter your speed.
You can't be 1 light year away from the particle horizon as it's not a fixed place in space. The particle horizon is the maximum distance from which light from particles could have travelled to the observer [you] in 13.8 billion years & it's approx 47 billion light years away in every direction [based on a certain definition of distance] from your current location. IF you could jump 47 billion light years you would find that you could see new parts of our universe beyond as it's thought the universe is at least 251 Hubble volumes in diameter [assuming a closed universe].
My question---
How a undergrad can learn and understand Quantum mechanics best way???
Books are still the best way. Read, repeat until you understand. Do the excersises. After you finish a topic summarize everything on one side of a sheet of paper. Don’t cheat and look at solutions.
Read a textbook and work problems. The same as any other physics student!
im not sure the scientists understand it so just have a good imagination ;)
@@alvarorodriguez1592 or if really clever, look at solutions first, then work out why. Saves working on the non solutions :D
You will need to know tensor math to work problems.
That Thanos analogy was a perfect way to put systemic societal problems in better perspective when talking to people who think that under all circumstances, anyone can "pull themselves up by their bootstraps."
Re; Eric Weinstein's Gauge Theory, for starters; the theory demands that there be 14 dimensions-yep, 14...
I will never be able to envisage that and I very much doubt whether more than a handful of people ever will but as it took 35 years to develop, it would be interesting to see it made more public and a lot more accessible to us mortals-if such a thing is possible.
Ian Morgan The first thing he has to do is to publish a paper. Before that he will only be taken seriously by amateurs.
Maybe do the math whilst administering DMT
Bell's theorem is only interesting because it teases out the very problem with trying to patch over a pure wave-function-of-the-universe theory with extra rules imposed by Copenhagen. But if you don't assume these extra rules you just don't have the problems that they brought with them. Einstein's view was kinda like Everett's in that way: as a therapeutic acceptance of the truth that was laid bare to them. They were stuck trying to map the new formulations into the old ones, but all they needed to do was accept the new ones and derive from them approximations that look like their older theories.
As much as i enjoy the drama that is the ongoing beef between Sean and Eric Weinstein I'd actually love to hear the two talk about this whole geometric unity hypothesis, Eric clearly lacks the skills needed to communicate it in an accesible way so someone like Sean could probably disect it far better than any of the other podcasters he talks to.
mutantdog Is there a drama? Eric hasn’t published a paper.
I don’t think there is any beef. Sean simply politely says the work is not interesting.
My take is, someone should ask Wolfram/ Weinstein so what are the consequences of their theories in Popperian sense. So far it seems like there are none. No experiments are proposed. No existing theories are improved / replaced. The whole thing looks like an ego play.
@@lennarthedlund9783 I think the drama comes more from the Weinstein camp really. Bret dismissing many worlds as a "stupid idea" at every opportunity seems like a dig at Sean, while Eric would rather complain about being disregarded by the physics community instead of actually trying to work with it.
@@miedzinshsmars8555 Yeah, Sean's disinterest is justified. Seems to me that the problem is more with Eric really. Personally, I'm skeptical about the whole idea but his maths are way beyond my limits and he really doesn't seem able to get across even the basics of it. Nevertheless, he's a public figure and presents himself as some sort of misunderstood genius. I'd really like to hear someone like Sean actually engage with him on the subject and, if necessary, decipher whether there's anything worthwhile in it or if it's all just an ego-play like you say.
Miedzinshs Mars And they haven’t published a paper.
Great answers! As far as the Wolfram project goes, you inadvertently misrepresented it here by indicating it isn't Lorentz invariant and that it doesn't accommodate quantum mechanics -- it does both those things, or claims to, and makes falsifiable arguments about things like speed of entanglement. I think his biggest gaffe is in how he launched and "marketed" this outside of the physics community (or that he marketed it in general), and he also failed to sum up the argument and findings in a coherent way. So I'm not a Wolfram apologist by any means, but if the laws of physics are emergent, mathematical, and based on some dead simple rule set there are worse places to start. Launch video is 4 hours but if you put it on 1.5x speed it flies by. th-cam.com/video/rbfFt2uNEyQ/w-d-xo.html
ADingoAteMyXRP Why didn’t you link to a paper?
@@lennarthedlund9783 Here you go: www.wolframphysics.org/technical-introduction/ As Sean mentioned the paper is 500 pages long and is in the process of being peer-reviewed, so dig in at your own risk. The ideas are summed up succinctly enough in the video. I know the science community is not a fan of Wolfram, but even if the work is way off the mark it may inspire better thinking.
is he doing anything different to the current clique in that sense? not as if hes debunking a proven theory
To be honest you speak too fast and I prefer it when you speak to an audience and subject content is more focused