Out of all the lectures I listen to on youtube, Sean Carroll's voice is most soothing.

I’m listening to your Google talk as this notification came out! Keep up the good work Sean.

My day suddenly got better

Long form answers are so much more satisfying.

Your "jump off a building" comment made my day. I tried it out my front door today 31 times. Sure enough, I didn't fly away... even though my mind wanted to. I must admit my mass/acceleration might need more than 20 cm to acquire flight in any of my engineering programs. Thanks for the lift in attitude rather than altitude. You Rock!

2:45:30 Light reflected off a mirror doesn't involve absorption and re-emission of light. It's a scattering process. Fluorescence involves the absorption and re-emission, and this has no preferential angle.

Great point also about the difficulty of a venture being a big reason for why it's worth it. Intellectual endeavor

I wanted to know your personal opinion on Sir Roger Penrose CCC theory, thank you .

Can you do an episode on the topic of John Wheeler? How did one person manage to attract and support so many highly successful grad students? That plus his own contributions has had a combined impact on the field that is truly awesome.

I am a computer scientist watching physics because it's interesting, glad to hear a physicist could find my field interesting.

I personally love the long answers and long podcasts like most people probably do. But the dumb questions are usually entertaining if they are funny and the dumb physics ones really really help people that are trying to learn. Not everybody is a graduate student! I know I have personally learned a ton from questions that many would consider dumb. I'm sure you can parse out the really awful ones unless they're funny. I would say a combination of the top 100 best questions with as long answers as possible would be perfect. Take a few and do them really long and keep the worst ones really short. Thanks for everything!!

To give another explanation of why time reversal doesn't reverse the direction of forces: Acceleration is the second derivative of position with respect to time d²x/dt². If you change to t'=-t, then you can calculate the new acceleration d²x/dt'² , and we get two minus signs from the chain rule (once for each time we differentiate by t'). So it cancels, and the acceleration is invariant

I dont know if you read these, but. I think a lot of people would be extremely interested in a podcast with Demis Hassabis. I think he is different from the other ML guests you have had and id be interested to hear his ideas on ML applications to physics, especially since his goal for ML is to better our scientific knowledge. Of course I dont want to make it seem like i am demanding anything, so only if it seems like something you would be interested in. But he is an expert in neuroscience, AI, and he does have experience interacting with scientists/philosophers. I'd love to see you two brilliant minds interact. Thanks for these great podcasts Sean!

We are at the center of the universe, because since the universe is not expanding into anything, the entire universe is the center of the universe, the same as saying that every point in the universe is the center. Some things are hard to express without circular logic.

I love hearing you tackle philosophical themes. Wish I had a fraction of your intellect.

Love your work keep it up!

Professor Carroll, Thank you for your contribution in popularising all the wonderful concepts modern physics was able to procure. Using the occasion I'd very much like to hear your thoughts about the nature of spacetime. I have always wondered if spacetime itself could be quantized and whether its proper to ask a question "is spacetime an emergent phenomenon of quantum fields existence? Or is it the other way round?" Can you suggest any materials which delve into such topic? What are your thoughts on this matter? In any case - all your work is very much appreciated. Godspeed!

Thank you

Simulation theory is gaining momentum in the broader scientific community.Physicist Tom Campbell has a very interesting TOE. I'd like to know Sean's opinion on the subject.

You just totally rock! And I can prove it!!

Sean, I have a good question I’ve never heard addressed. Does the double slit delayed choice quantum eraser make worlds re-cohere when the quantum information is erased?

Is time the result of (i.e., emergent due to) motion? Or, does time exist before motion (perhaps 'potential time', akin to potential energy?) which allows motion and change to occur at all in the first place? If all motion (including motion of all subatomic particles, etc.) were to somehow freeze, would that mean time would freeze; and then when things start moving again time exists (results) again? Or, is time related to degrees of freedom (to move or potentially move) in 3 (or more) dimensional space? Or, none of the above?

Are questions submitted in advance? If live, when is the March 2021 edition scheduled for? Thanks

Wonderful

2:45:00 pretty sure you could imagine walking on a flat torus forever without getting back to where you started

Sean Carroll is DA MAN.

Regarding the 'edge of the universe' question, Jayne Cobb (Firefly) perhaps put it best: "I've been to the edge. It's just more space."

I appreciate the hard work and effort you put in to these, Sean, but how you dismissed one of the first questions regarding how long would it take our fastest rocket to pass Voyager I was, well, lame and downright pompous. I mean, you seemed delighted to talk about your Colbert interview…That person could have waited a long time to get the opportunity to ask you that, or worse yet, what if it was a kid and you are his hero? I quickly Googled something and found that NASA has a probe that can travel 393,044 km/hr. Is that the fastest? Is it technically a rocket? No, but it’s something. Again, thanks for what you do, it’s more than most scientists do, but you could do better in these situations. Cheers.

Can it be said that everything has a relationship to harmony, logistics and things from which actions emerge.

2hrs 45: If anyone wants a simple but comprehensive answer to this question (why are photons reflected at an angle equal to the angle of entry by a mirror?) - Richard Feynman used exactly this an an example to show how QED can explain the behavior of light in his book QED - the strange theory of light and matter, which he wrote for an interested layman audience. It's the first 10 pages of chapter 2: Photons - Particles of light. There's no way to squeeze the answer into a KZfaq comment, I'm afraid.

49:00 If you throw an apple into the air and it falls on the ground and then a minute later you reverse time, then a minute into the reverse time direction the apple jumps off the ground of its own accord and lands in your hand.

Hope you don't mind if I post this on your site since I was hoping to get feedback from people like you with regards to one of my crazy ideas: So here goes: If and when we leave this Earth it would be very helpful if we could communicate instantaneously back to here or wherever else we end up being. Sound nuts right. Well maybe not. Here is part of what I have in mind. Since Entangled Particles seem to be connected in such a way that each knows instantly, the "spin state" of the other twin ,at least for this discussion lets suppose they do. Then here is my thought. What if every mission into deep space were to carry with them a device that contained some number of Entangled particles that were initially entangled with their entangled twins at their point of origin. Then if it were possible to construct within that device a method wherein they could be arranged, for want of a better word, into a position or state such that they could be encoded with binary states that could be altered then maybe messages could be sent from place to place seemingly instantaneously. I say "seemingly" since it may be that what we see as instantaneous may not in fact be instantaneous when our methods of measurement progress to a point where we can be more precise.Think of up/down as 0/1.if that helps.For all you Star Trek Fans who understand Binary, think of a light board with only red/green lights fixed behind it. At each position on the board the light could be either one or the other now picture the spin of the "up" particle being"red" and the "down" spin being green. then it should be possible to encode the msg in binary on the entangled particles at one location and that msg would appear instantly on the remote board where the device containing the entangled twin particles was located......Maybe. Maybe a primitive form of this device could be tested on the Space Station to verify my hypothesis.

9:05 He did? Yes indeed They are not. I think of you and also Brian Green.

My non-patreon question won’t be answered, but here it is anyways. Is there such a thing as free will in the many worlds interpretation?

Heres a question. How does the quantum flux not violate causality?

The question on the legal system is more in line with how can you punish people when the universe is predetermined. The only answer I get from anyone is basically just cause.

Do you think that observation should be included in quantum mechanics as the universe formation does not depend on the human race?

Is there anything in nature other than quantum physics that is also governed by the Schrödinger equation?

How long would it take for a 1 Kg black hole to evaporate?

If the Flash can move at speeds close to the speed of light, several times a day for years, why does time remain relative between him and everyone else? In other words, shouldn't everyone around him start to get older and older each time he runs at close to the speed of light? My theory is he's using wormhole technology.

I have become extremely jaded with mainstream Academia. First I was forced to suppress my Mathematical intuition. I could jump from step 1 or 2 to 10 intuitively. I didn’t receive any marks for that. I was disciplined. Forced to believe memory storage and recall is intelligence. This is a great disservice to Humanity. A down right crime against Humanity. We will suffer immensely if this is not corrected sooner than later.

I'd love to see (or hear) a debate / conversation with you and Eric Weinstein. He is a very smart guy but I don't trust people who think they have all the answers. He believes we should not be wasting time with string theory anymore, because it offers no testable proofs. Would be amazing with some great ideas covered.

Guacamole.

8 ’feet’ tall? Come on now,, it is not the dark ages anymore. Use standard units of measurement!

If wave function collapse when we measure it then what about general relativity ?? (matter tells space how to curve)

At around 11:19, I remember this great talk at the RI. Was it really that long ago? kzfaq.info/get/bejne/lZ6Sm9d2zKicfaM.html

I love this comment about rising authoritarianism and climate change and I’m posing we look to see if they are connected through science. This is multifactorial, with humans losing ten IQ points over a century. Leaded gasoline, phthalates now in plastics, we are making choices that are impacting our environment, this doesn’t look good. We also see in studies, rising narcissism and cluster B character disorders, is this cultural? Environmental? All of the above? Will humanity swoop and recover to become enlightened In the future as to what causes these events? I sure hope we haven’t poisoned ourselves so cognition has been impaired.

Is string theory at a dead end?

At least 15 people didn’t like your answer to their question, haha.

don't mention zombies I got kicked off twitter for talking about surviving a zombie bite, apparently I was the one spreading hate not the zombie that bit me

How is the many-worlds theory any different than saying everything that can happen does happen? Is such a sentiment really a useful approach towards gaining better understanding of the universe? I think the weirdness of quantum physics is caused by the creation of mathematical formalism in a universe that has no strict formalism in itself! As Sean says we are all Wishful thinkers who tend to want certain things to be true. It seems like Sean just tends to gravitate towards liking a deterministic model Anyway not sure why positing an incalculable creation of universes every second as reality unfolds is helpful Why not just say we have a probabilistic model because inherently the act of modeling the universe is probabilistic at the most fundamental levels Most of the confusion around quantum physics comes from the fact that in order to measure you have to affect. Meaning you have to actually bounce photons off very small Quantum systems Human intuition is very bad at understanding the relationship between very small, relationships of matter and energy And our language and common cultural conceptions are very clumsy at trying to illuminate these relationships! All the supposed Quantum spookiness like superposition and tunneling is created by a misunderstanding of how the introduction of observational measurement photons effect physics at the most fundamental level Like for example the double slit experiment can easily be explained by the fact that photons have a huge effect at the quantum level So of course we have a radically different experiment when one is completely undisturbed, and the second version has the addition of instruments interfering with the original setup by detecting the happenings with photons. Or an interfering energetic system! Anyway Sean's a really smart guy and I have learned quite a bit from his work. But I definitely see a pattern in his tendency to idealize laplace's demon and the many-worlds interpretation of quantum physics As Sean himself has said just because we can conceive of things doesn't mean that they are necessarily helpful, especially when they are in flagrant violation of everything we know about matter and energy LaPlace is demon is in flagrant violation of everything we know about both classical and quantum mechanics. So not sure why that is a useful construct. And the fact that he keeps returning to talking about laplace's demon and many worlds leads me to believe that maybe that's just a personal bias of his and not an accurate assessment Again really smart guy, really good scientist. Interesting podcast. But from what I can gather the majority of the scientific Community is not on board with many-worlds and I'll put more likelihood in that camp. Until I see more evidence to believe otherwise.

Star Trek had "recorders?" Star Trek walkie-talkies? All geek cred lost.

Isn't a strange contradiction to name something "Ask Me Anything", but then say they can't ask you anything. Considering all the lies in today's world, it would be worth changing to simply Q&A, just to create one less lie.

Why do people use the word nothing as if it were something.?? What is nothing?? How can you define nothing?🤔🥴🤨🤔

Which one of these (if any)is more likely to be accurate ? 1 if we live in a block time universe, then LaPlace’s demon exists. 2 if LaPlace’s demon exists, then we live in a block time universe. 3 if we don’t live in a block time universe, then LaPlace’s demon does not exist 4 if LaPlaces demon does not exist, then we don’t live in a block time universe.

danggg sean is not havin any of eric weinstein's shit

I wish you had more time to answer. Less questions, people! :D

Shouldn't you be working?

"Cheating is good, you should cheat" - Sean Carroll 2/20/2021

A permanent lockdown with no travel is the only safe option.