Episode 2: Carlo Rovelli on Quantum Mechanics, Spacetime, and Reality
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- Опубликовано: 9 июл 2018
- www.preposterousuniverse.com/...
Quantum mechanics and general relativity are the two great triumphs of twentieth-century theoretical physics. Unfortunately, they don't play well together -- despite years of effort, we currently lack a completely successful quantum theory of gravity, although there are some promising ideas out there. Carlo Rovelli is a pioneer of one of those ideas, loop quantum gravity, as well as the bestselling author of such books as Seven Brief Lessons on Physics and the recent The Order of Time. We talk about how to make progress on this knotty problem, including whether string theory will play a role (Carlo thinks not).
Carlo Rovelli is a professor of theoretical physics at the Centre de Physique Théorique de Luminy of Aix-Marseille University in France. In 1988, he and Abhay Ashtekar and Lee Smolin introduced the idea of loop quantum gravity. He is also the author of the "relational" interpretation of quantum mechanics. 
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Four podcasts are dropping this week, in honor of our launch! After that, one every week or two (depending on how popular it gets).
The more the better! Keep them coming. We need your unique conversation skills, tone, and civility. Thank you!
sean this is going to get massive don't you worry about it. people should be paying to hear the knowledge you have amassed
Thanks for explaining. I haven't had time to watch the first one and when I saw the second I thought there's no way I can possibly keep up with this frequency of upload.
Great! I hope a lot of people tune in. I agree with a lot of the other commenters, that the addition of video would increase your viewership/listenership substantially. The technical barriers to doing video podcasts are fairly low now and there are a ton of potential guests that are already in SoCal area or will be passing through that could meet at your office or at a basic studio to record the episode. Your message and understanding is really valuable, so I’ll be thrilled to see you be as successful in this medium as possible. I have web dev and some audio/video experience, in SoCal, and would happy to assist pro bono.
Fantastic, and BTW I loved this one!
Although not a physicist, just a lawyer, although not a native English speaker, just a Swiss German, your lectures help me in enlarging my bumble knowledge of, among others, physics in me older years. I am outmost thankful.
There is no debate, this podcast is awesome
Okay
Prove it!
sorry to be so off topic but does any of you know of a trick to log back into an Instagram account??
I was dumb lost the account password. I would love any tricks you can give me!
@Shepard Zane instablaster ;)
@Ian Moshe Thanks for your reply. I got to the site through google and I'm waiting for the hacking stuff atm.
I see it takes a while so I will get back to you later when my account password hopefully is recovered.
Please, more episodes with Dr. Rovelli going deeper into Loop Quantum Gravity. This was a really good one!
Sean thank you for making these. These past two podcasts are packed full of value and insight, like an oasis in the barren landscape of word vomit podcasts
That you keep the discussion at a high level and make us do serious work to follow/understand is so refreshing and very much appreciated.
Thanks for hosting this podcast Sean. I've always loved your interviews and talks on other shows. I can't wait to see what other amazing guests you'll have on!
Very glad you've decided to do this Sean! It's really solid. Well done man! Broadcasting far and wide...
Great stuff Sean, I'm so happy that a scientist/philosopher of your caliber is producing these high quality pod casts with equally impressive guests...thank you!
Excellent once again Sean! These podcasts are just wonderful! The comments show a very nice caliber of listeners who have some level of understanding these complex topics. I am looking forward to many more of these sir! Carlo Rovelli was a wonderful guest as well!
Fantastic episode and a great start to your series Mr. Carroll. Can' t wait for more episodes! Love your work and love to hear your views and opinions on everything. I hope this really takes off for you sir so we can get more great conversations and topics from you and your guests!!!!
Ed Witten as a guest would be rare and unique.
I watch many of this type of videos, but I have never seen him as a guest. Does he do videos, or have I just missed him?
For what it's worth I went to one of his talks years ago. I do not have the impression he would discuss physics anywhere near a general audiences level... The math would retain meaning better than any words.
Came here from your conversation on Joe Rogan. Loving the podcast - right up the alley with what I'm interested in! Keep up the good work!
So glad to have found your podcast (this episode in particular) right after watching the Joe Rogan Experience episode you were on last year. You have sparked my interest in quantum physics! Can't wait for all the new episodes to come; all 4 that I have listened to so far have been great.
Thanks!
So refreshing to hear a pod like this! Keep it going!
I am loving this podcast! Thank you for it.
Very Happy you are starting this podcast! Thanks Sean!
The only podcast ever where Lee Smolin gets named dropped lol love your work Sean, thanks to you and Caltech for all the public engagement like this. Your efforts are greatly appreciated
Great interview with Carlo Rovelli! These are exciting times and Carlo is a fantastic 'splainer of all things physics, as is Sean. I highly recommend both Carlo's recent books, as I do Sean's from Eternity to Here.
I would absolutely love it if you could explain the implications and inner-workings of the double slit quantum eraser experiment. Thank you. Sharing this with the people around me.
Sean, thank yooooou for starting your own podcast! I already have the feeling it's is going to be in my top five.
I found out about you through a Joe Rogan podcast and then looked for your podcast. I listened to the first and now listening to this one. I also subscribed and am just fascinated by all this. Keep them coming. These are awesome. Thank you!
Thank you, thank you, thank you. Great stuff in these podcasts. Can't wait to listen to you and your next guest.
You definitely need to go full video. It will take your podcasts to the next level. Loved it btw
This podcast is essential. Please keep this going.
Continue these!! Been lookin for a good mind warping, head scratching, podcast with people who ACTUALLY know what they’re talking about. Keep it up 👍🏽
Love this content and will definitely be listening to future episodes. Don't mind the no video thing at all, as I'm listening to these while doing other things.
Fascinating conversation... full of clarity.
Excellent. Format is perfect. I listen at work, so I have no need for video.
Please do record videos as well!
yes,a Joe Rogan format type would be awesome.Monologues or dialogues would enrich every viewer.
How would that improve it?
Alan Garland
Because many people don't like staring at a static picture.
@@alangarland8571 I can watch it instead of just listening?
yes!
Hell yes Sean! You’re killing it buddy. Love these talks
This podcast is fantastic! Makes me want to pick up my old books and calculate the universe :)
I've been waiting so long for Sean Carroll to do a podcast! RUclips has delivered the goods.
Great podcast, so glad you have decided to do this. I would love to hear you speak with Brian Cox.
Such an interesting conversation, wish it was longer!
Love you Sean. So happy you started a podcast! Subscribed!
Great podcast. Thank you so much.
Nice podcast!
Thank you!
Loving these mindscape casts, keep em comming !
Sean you are so intelligent and well spoken! I luxuriate in listening to your thoughts and high language!
Thanks for the great podcast Sean Carroll 🙂🙂
Wonderful lecturer. A rock star!
hey I know some people will be like woah you just posted yesterday but wow I would NOT MIND A PODCAST EVERY DAY like seriously I’d rather listen to SC ask questions every day than basically anything else so LETS GO
Sean:
I am a big fan of yours. I admire (and envy) what a great communicator you are. I enjoy this podcast as well. I can see why you have the office of R.F)!
Awesome, didn't want it to end.
Great talk on the most recent thoughts about the subject.
This is amazing! Good job!
Excellent discussion.
I’m personally very happy that you read your own audiobooks.
Professor Carroll, can you please dedicate a portion of your podcast explaining your choice for the many world interpretation of QM for the layman. I get the impression that "many worlds" is simply choosing the lesser of the two evils, where the other one is to conveniently discard the other possibility of the wave function collapse. So is it just a temporary "solution" until a better theory comes along, or do you actually think the many worlds is accurately modeling "reality" as we know it? And while the many worlds is mathematically elegant, intuitively it's hard to swallow. I do agree with Rovelli that it comes with heavy ontology, and it's not the fact of the many worlds itself, it's the implications. Our way of reasoning in everything we do in life, including classical theories, is structured to think along a tempo-spatial *causal* line. I don't want to put a gun to my head because there's high likelihood of me getting killed, plain simple. I don't see how you can justify clearly bad decisions in the many worlds framework. After all, all possibilities will be realized, including me being still alive. Does the notion of cause and effect retire from the conversation? I'm afraid more explaining work needs to be done besides simply saying our intuition didn't evolve to do theoretical physics. How does the many worlds make a difference, if any, in how we interact with the world?
PavelSTL
Many Worlds is simply the interpretation described by the math. To get to any other interpretation you have to add postulations (for example wave function collapse) that do not appear anywhere in the math.
If you think that the Shrodinger equation always explains the dynamics of quantum systems then you are necessarily left with MWI, you must add extra math to escape this conclusion but Everrett argued that this was unnecessary when the Schodinger equation already explained observation.
To add additional math to escape a conclusion you don't like, even though that conclusion fits the data, seems extremely ad hoc and a violation of Occam's Razor which is why Sean doesn't like to do it.
"I get the impression that "many worlds" is simply choosing the lesser of the two evils, where the other one is to conveniently discard the other possibility of the wave function collapse."
That assumes that there is a wave function collapse, but MWI rejects that notion. There is decoherence, but no wave function collapse (hence why the Shrodinger equation always applies, unlike in other interpretations which add extraneous math to attain wavefunction collapse).
And I should add that in other interpretations other possibilities are not "conveniently discarded" when the wavefunction collapses, that is what wavefunction collapse is, the other possibilities disappearing.
"So is it just a temporary "solution" until a better theory comes along, or do you actually think the many worlds is accurately modeling "reality" as we know it? "
He thinks the latter.
"And while the many worlds is mathematically elegant, intuitively it's hard to swallow."
Being counter intuitive is in no way an argument against a theory, the universe doesn't exist to satisfy your intuitions.
"Does the notion of cause and effect retire from the conversation?"
Of course not, MWI is entirely deterministic.
"I'm afraid more explaining work needs to be done besides simply saying our intuition didn't evolve to do theoretical physics."
Why? He already has countless lectures and blogs on YT, as well as several books that explain MWI and his reasoning behind favouring it. For example:
www.preposterousuniverse.com/blog/2014/06/30/why-the-many-worlds-formulation-of-quantum-mechanics-is-probably-correct/
"How does the many worlds make a difference, if any, in how we interact with the world?"
It doesn't.
@@Oners82 You're not Professor Carroll.
@@cammo777
No shit Sherlock, that is why I linked to Carroll's blog which confirms everything I said regarding his opinions.
@@Oners82 : Spot on explanation of what Sean Carroll is saying and is certainly a very compelling argument IMOP. There is some difficulty, I think, as to whether other worlds have the same ontological status as this one (as David Deutsch seems to suggest - see "Fabric of Reality") or whether at least some of those other worlds will fade out as they become more and more bizarre - compare Feynman's explanation of how a light beam actually goes every which way between two points, but appears to go in a straight line because many paths cancel out (in his book QED).
@@roqsteady5290
If MWI is true then other worlds by definition have the IDENTICAL ontological status as this one. It is the epistemological justification that is troublesome, not the ontological status. And I am a big fan of Deutsch but have not read that book, just going to order it now on Amazon!
And sorry, but your last sentence is incomplete. You say something about worlds "fading out" but the end of the sentence is not visible. However from the bit that I can read, this is simply a misunderstanding of what MWI actually says about reality. Other worlds cannot "fade away" anymore than this world can "fade away". ALL worlds simply evolve according to dynamical laws, and whether this leads to thermal equilibrium, cyclic cosmology or whatever else, the world still exists!
More of these please!
Very interesting and inspiring discussion. It is nice giving the chance to people working on alternative approaches to quantum qravity to present their theories to the non-specialized public. I suggest inviting someone from the field of condensed matter in future podcasts, to discuss relevant modern topics like, topological matter and phase transitions, many-body phenomena, entanglement and quantum information, etc.
i like how physics is becoming popular and actually changing the common sense about reality we had in last century. i think there is something really new coming from it in arts, literature, and human expression in general. it's good because we are now living in a pretty dull era
I have gardening to do today. This will make it far more enjoyable :)
You have a great voice, Sean!
Please do not stop podcasting
Great Choice !
Amazing Podcast, Sean! I specifically love the intro where you give us some backgrond information on the guest and their area of expertise. Really helps fully digest the whole podcast. Cheers!
Excellent stuff.
Just finished listening to the 1st one.
Sean, first, your podcast is great. Thanks for the initiative. We have discovered that you are also a great host, always putting in the right context questions (and answers). Carlo Rovelli: Quantum Gravity is a terrific matter (Carlos´ specialisation) but the discussion I would have loved to listen is about THE ARROW OF TIME. Both of you have strong positions about this subject. What do you think about the PERSPECTIVAL thesis of Carlo? You probably had this discussion in private with him. Please, create a podcast about this matter, in general. Cheers. Antonio
Already, I'm still only half way though the last one.
Wait - he is travelling at close to light speeds, it just APPEARS to us that they are coming in fast :)
Good show Sean... the imagery of interlinked quantum gravity loops is attractive but it lead me to wonder would this net-like structure exist in two demensions,or three ? I get the fact that they themselves, would BE spacetime, but interesting differences are suggested by both models.
Very nice. Thanks a lot!
Sean, I have a black hole question. How close to the event horizon or the physical black hole do you get before the gravity differences between head and feet begin to cause joint pain?
Before the event horizon or after?
You're awesome. I love your work. You should totally interview fellow Everettian and philosophy of physics, David Wallace!
Very good podcast. Rovelli emphasized correctly that it is a big deal that evidence for supersymmetry haven't shown up yet in the CERN experiments
I like that you are not afraid to disagree.
Love the podcast so far! See it you can get David Deutsch!
Sean, what are some implications of the LHC not finding evidence for SUSY? Do you we simply probe at higher energies?
I know you and Carlo touch on this near the end of but wanted to hear your thoughts directly.
Gracias por este podcast. Ojalá tuviera subs en Español para alcanzar a más personas
Please show you talking with the person you are interviewing. A picture on for and hour does not do justice to a podcast on RUclips. Love your work! Video is needed!!! Thank you for educating all of us.
When I move from point A to point B, do I move through space, or does space move through me? Your answer will be leveraged with reconciliation with 'local' causal shared symmetry which necessitates [differential time: t'] for any object that exhibit mass.
Im already excited. Quantum was my favourite module. Can you do something on QED? That would be cool.
I’m so happy!
So glad you started this podcast! Would be great if you made an episode on Many-worlds interpretation some time. I'd like to know why it's your favourite. What good reasons do you think you have for supporting this theory and not some other?
Vitaly Kalashnikov
He explains his reasons here:
www.preposterousuniverse.com/blog/2014/06/30/why-the-many-worlds-formulation-of-quantum-mechanics-is-probably-correct/
Can you talk with Nima Arkani-Hamed? I'm really intrigued by the amplituhedron and EFThedron.
Thankyou SC :)
Sean, I love your fresh podcast. It would be awesome if you had Nima Arkani-Hamed on. Would love to hear you two exchange ideas.
Thanks Sean. Do you think the speed of light has ever varied over time?
Sean, you rock bro. Me, You, and Hugh. That's the name of my unwritten script. It'll be terrible. You'll love it.
Amazing! I really loved the quantization of the Gravity part @ 30-35 minutes.
However, i was astonished to not find a choice both are wrong and yet both are right @ 1:05. Don't you believe what you say, sir?
Having trouble understanding why the EM field can be measured in an arbitrarily small volume of phase space, but that the gravity field cannot. (Was not previously aware of the "Landau error".) Wouldn't the energy in the EM field have mass and cause a black hole in the gravity-space field? Don't these fields share a phase space? Did I hear these arguments incorrectly?
thank you
Great podcasts Sean, thank you. You touched on something that is of great interest to me. Super Symmetry. We have had one major energy upgrade at CERN and there have been NO detections of super symmetric particles. Yes, they could exist at higher energies. But what if they don't show up? If super symmetry is dead, would this not mean big problems for the standard model? Thanks...
Gully Foyle ..it would cause a MAJOR reassessment of many theories BASED on supersymmetry, but remember,..as beautiful as supersymmetry is , it is not per se, the standard model but a potential extension of it...sadly too,, because the theory is so elegant..
Gully Foyle
"If super symmetry is dead, would this not mean big problems for the standard model? Thanks..."
No because the Standard Model does not entail that Supersymmetry is true.
Maybe it's just me, but when I think of the Speed of Light in terms of Speed of Time, things tend to make more sense.
Can someone explain this to me. I watched a video with Carlo and he talked about black holes and that the star still resides deep inside the black hole. Not the singularity. Actual star. I never heard that before.
love Sean !
"Benedict Cumberbunch" haha
this would be an ideal vehicle for moving naturalism forward ... you can use that if you like
"I see our direct experience of reality is tremendously overrated frankly" hilarious :)
Hey Sean, please do an episode on quantum Darwinism.
Nice podcast and format Sean, love it! I also like Closer to Truth with Robert Lawrence Kuhn. It would be great to turn the table on Robert to explore what he has come to believe from his quest to find truth. Ask him if he really means it when he says he would like to believe in God or whether he is cleverly catering to his religious interviewees so they can feel comfortable letting out their worst babble. Other than that appreciate and expect your podcast will leave out the woo woo artists.
You're a clown. Get a life.
It's interesting to try to think about cognitive dissonance in relation to new perspectives on gravity from Verlinde (Emergent gravity??) to Rovelli and Smolin (Loop) to MOND, etc., but I am going with Robinson's science fiction book, Mars Trilogy, that merges Loop Quantum Gravity and String Theory into one, if Cumberbatch reads the audio version.
Great podcasts, please level out the audio though, little sharp on headphones.
Nice!
Wazoo, the idiom and not the other, I am going to need a repeat listen if not more, maybe one or two of the books will help.
You cannot be "a realist about reality" because the whole aim of physics is to establish what physical reality is, so you don't have the ground to be a realist to start with. That's precisely what you are looking for: the ground where you can actually asume a realist position. If that ground does not pertain to the category of the actual, then your realist position can't be what you say it is, Sean. It's not realism but idealism, which is what you are trying to avoid.
I'd love to see Sean interview people with a different perspective on the physics of gravity and space-time than the ones that already get so much publicity (string theory, for example). Grigory Volovik and Xiao-Gang Wen have amazing results for the emergence of both particles and forces from underlying strongly-correlated degrees of freedom. I think interviewing them would be refreshing for a lot of listeners.
Presumambly Carlo was talking about this paper: arxiv.org/pdf/1707.06050.pdf. Just in case someone was interested.