Episode 18: Clifford Johnson on What's So Great About Superstring Theory

[@coolio4366]

Aw yea. I've been waiting forever to hear Sean really get into string theory.

[@ethanharvey4869]

Thanks for keeping the ball rolling Sean! Always a pleasant surprise to see your episodes pop up and reguardless of the amount of viewers I would say you probably have one of the stronger and more appreciative/supportive base followings where +90% of your viewers are genuinely plugged in and listening to learning and enjoying your entire episodes beginning to end. So thanks again bro keep doing you!

[@sebastjanbrezovnik5250]

Keep going, thanks for taking the time beside work to record this.

[@FABRIZIOZPH]

I cannot imagine better way of spending some time on youtube

[@ReddooryogaSH]

Please do an interview with Leonard Susskind!

[@txnygotw]

I second this.

[@account1307]

Yeees!

[@xixeoxeno]

Two of my heroes coming together, yes please :’)

[@Starlite4321]

Absolutely. And it seems like he might be open to doing something like this?

[@naimulhaq9626]

Please do an interview with Maldacena.

[@d-5037]

This was great. A bit over my head some parts, but I'll definately come back for a second round when I'm more informed. I hope I'd hear more from Clifford Johnson in the future.

[@chewyjello1]

The Elegant Universe documentary sparked my interest in science. I brought it home from the library one day, and never returned it lol. Then I dug it up again when I had my daughter. Some people had their babies watch Little Einstein videos, I had my daughter watch The Elegant Universe over and over and over. If she was fussy it would calm her right down. That documentary is very special to me in more than one way!

[@Starlite4321]

Damn!! Why can't these things be longer? Sean, you need to have special two hour episodes with guys like this PLUS subsequent Parts 2, Part 3 ...

[@feynman_3224]

As always it was wonderful. Keep making podcast Dr. Carroll.

[@Anyreck]

Its wonderful to have physics discussed by someone who sounds just like Cliff Richard, and who's called Cliff! We'd like to have a romp through those useful mathematical technologies (techniques?) to cope with higher dimensions one day, preferably with some graphics. Thanks for all the string!

[@mattd8725]

It bothers me when Sean calls the Phenomenal world the Real world. I guess you could say that I Kant stand it.

[@woody7652]

Thank you very much, Sean.

[@ZacksMetalRiffs]

Hey! I saw you on Sam's comment section and now you're here too!

[@heymotivator2231]

Love the podcast, channel deserves more subs!

[@RaysAstrophotography]

Sean, thanks for the lecture. Will listen during the day.

[@cordatusscire344]

Thanks for the upload! I enjoy your work greatly :)

[@joyecolbeck4490]

I really enjoyed that, thanks. I confess I'm not able to fully comprehend it, but I loved it nevertheless.

[@saadibnasaadhusain]

I'm reading the book on D-branes for my thesis - it's right up there with Polchinski's text.

[@stevephillips8083]

Talking about science is fun! Thanks, Sean.

[@severinschmid4808]

Great podcast! But it also made me think that having Peter Woit or Lee Smolin would be really interesting - along the lines of "What's Not So Great About String Theory". Anyways, will keep listening either way ;)

[@ThePrinceVegeta7]

Sean and Brian are my heroes

[@EldafoMadrengo397]

Very interesting episode, keep up the awesome work!

[@chrisrecord5625]

Astronomer Jill Tarter reportedly remarked that the Drake equation was a wonderful way to organize our ignorance. I sometimes think about that quote in reference to string theory. i know it's too harsh an idea, although, in M Theory, some say the M is for Magic. However, string theory helps organize our questions with regard to vacuum states, dimensions, etc., and trying to explain string theory to the masses (like me) is similar to trying to summarize the plots in Game of Thrones in an hour.

[@chrisrecord5625]

Ps, Mindscape is an effective anecdote to "Transgressing the Boundaries: Toward a Transformative Hermeneutics of Quantum Gravity" by Sokal.

[@ericcotter1984]

You're a fantastic interviewer, you let the interviewee explain himself as much as possible, not such a common thing.

[@ryanjames2673]

Great podcast! Thank you sean 😁

[@calwerz]

If 26 dimensions go down to 10 by adding a new type of particles (fermions), maybe adding a third type would help those dimensions go down to our observed 3. But I guess that possibility is already ruled out.

[@desgreene2243]

Great interview. Becoming more and more difficult to justify intellectual resources being expended on Superstring/brane theory. Does it even satisfy theory status in being unable to predict anything that is currently if ever experimentally proven...

[@tnewanz]

Great interview.

[@naimulhaq9626]

Positive and negative cosmological constant may have to do with SUSY, and may reveal more about matter phases.

[@ggrthemostgodless8713]

I think all the physicists ignore "too much" or more than they should, Gödel's Incompleteness Theorem. It was no small thing Einstein himself thought Of Gödel as the best time spent when he took those walks with him talking about these subjects. I can't remember exactly how he described him, but he saw him as having achieved a higher understanding of it all, Einstein was LEARNING from Gödel. He is the most underrated man in these areas of knowledge, and the most damagingly ignored one.

[@sawwil936]

The lack of someone claiming first is odd

[@dxhelios7902]

Would be nice to hear something about the time. Why we can create mass from energy and energy from mass, but we cannot do the same with time and energy. Create time or convert it to energy. Why photon does not experience time, how? How much time existed at the time of big bang. If it has not existed then where it came from. If photon does not experience time, maybe it is time. So many interesting topics...

[@bkparikh]

This talk unlike several other speakers was not clear. Maybe Dr Carroll needs to redirect him more to clarify the speaker

[@victorjohnston7705]

[In quantum theory] “the distinction between reality and our knowledge of reality has become lost,... “ Edwin Jaynes Do probabilities belong to objects or events in the physical world or do they only belong to a human brain observing and acquiring knowledge about the behavior of such phenomena. To address this question let’s Imagine throwing a die that lands with the number one showing on its upper surface. It is difficult to believe that the die knows that it should land in that manner on approximately one sixth of the times it is tossed. For that to occur, the die would have to keep track of all its prior outcomes to ensure that the one-up event occurs on approximately one sixth of the times. In contrast, a human brain has a memory that can, and does, keep track of these repeated events and can eventually estimate the subjective probability of the one-up result. Perhaps we could argue that it’s not the die, per se, but rather it is the laws of physics that determine the probability. The laws of physics include the action of forces, friction, and angular momentum etc., but they don’t count or keep track of which face of the die will end up on the top surface on any throw. Most Importantly, every throw of the die is totally independent from, and not related in any way to any prior or future throw. Just like the die by itself, the laws of physics do not keep track of, or calculate, the probability of any one event. The concept of probability is strictly a human construction invented by Pierre de Fermat and Blaise Pascal in the seventeenth century. Human brains can, and do, subjectively compute the likelihood of possible outcomes based on past experiences, and can modify these likelihoods on the basis of future observations. In addition, a human brain can also classify an event, like the sound of gun shot, as “surprising” (a low subjective probability) in one context (a supermarket), or “expected” (a high subjective probability) in another situation (a shooting range). That is, probability is not only subjective and personal, it is also context dependent (a conditional probability), that is continuously updated by an individual’s personal experiences. This computation and update of conditional probabilities has also been mathematically modeled by Thomas Bayes in the middle of the eighteenth century. Probability theory and Bayesian statistics are useful tools for simulating how humans acquire knowledge from observing the physical world around them: that is, epistemological in origin. They are not, however, attributes that belong to physical objects or events :that is, they are not ontological in origin. So treating the probability of an event’s occurrence as if it belongs to the external physical world is a serious misattribution. The Schrödinger wavefunction is not reality itself, but only a mathematical description of what a human can know about reality before it is observed (or interacts with the macro world). Within an hour there is a 0.5 probability of Schrödinger’s cat being alive (it is either alive or not alive, not both) but when observed by the experimenter her subjective probability becomes 1 (or 0). No superimposed cats, no faster than light messages and no multi worlds

[@semidemiurge]

This is more like it!

[@eduardoreyes1272]

Espectacular!!

[@michaelnelson3752]

I didn't know that Christopher Walken was a guest on this show

[@mikeg9b]

2:17 Did he just call physicists "smart cookies?" hahaha!

[@dakid3429]

Good one SC, tks

[@ggrthemostgodless8713]

I wish they would talk about the language barrier in explaining these non-ordinary realities, after all Language is for the everyday "common" reality, a tool of survival.... will it be expanded MUCH into these new areas, is it the right tool for that, or is even math the right tool? Will they invent another one, another META-language to work with these topics.... I think Feyman did something like that with his wiggly arrows and things, a condensation of A LOT OF MATH, or even an ENTITY, which they all agreed on as being correct, into a single symbol. The language barrier: the main issue with that, which I think is still solvable, is that those things have to still de explained or described with Language, and really, even if we adopt the best WORDS or sounds of all languages into this one to describe new things, or symbols that best describe those new things, how much can we expand this one language before it BECOMES ANOTHER no one ordinary can understand.... Oh, it this has already happen to some extent with it, when explaining these topics!!

[@mycount64]

we need some new math... both for strings and quantum mechanics

[@wyeth1023]

More like this!!

[@kennethmurphy8122]

Yep

[@wslopez91]

This was the only podcast I could not keep up with. I am an idiot :(

[@jorisboulet3619]

If learned 1 new thing or youre thinking was challenged. Worth it.

[@SolSystemDiplomat]

I turned off Mia khalifa for this

[@insertoyouroemail]

Dude, you can do both at the same time.

[@rollingrock3480]

Good, she's ugly.

[@88_TROUBLE_88]

I have no idea what that is and don't care

[@SolSystemDiplomat]

Christopher Frasher just turn on private mode before you google her

[@NoActuallyGo-KCUF-Yourself]

Mia will wait for you.

[@MyYTwatcher]

Thank you for interesting podcast, dr Carroll. Despite decent education (chemist) this theoretical physics is too far beyond my understanding. Do you think you could do some review type video about current state of the string theory with all pros and cons? From what I read it seems that the theory predicts things which are later not observed and because of this mismatch with reality the theoretical physicists update the theory, but again fail to match reality. From what I understand the string theory needs supersymetry but no supersymetrical particles have been found at LHC yet. What keeps people in, for lack of better expression, believing that ST is correct so they spent their prime on working on it? I find ST quite interesting but somehow it seems to me that it is more some kind of intelectual excercise then connection to the reality we live in.

[@keyun12]

Once you start bringing on theologians, please bring Ed Feser or David Bentley Hart.

[@HunterYavitz]

Professor Carroll, will you be doing any public speaking events anytime soon? I missed you with Sam Harris.

[@arldoran]

You can not fix a broken theory by adding extra dimensions.

[@MariusSigurdsen]

Love the podcast! But! Sometimes I fall asleep and get brutally woken up by that ending music.. Can you tone it down or turn it off please? It doesn't really serve any purpose :)

[@DanielFoland]

Beware the ides of October...

[@account1307]

Leonard Susskind!

[@account1307]

Cn someone tell me whether this guys accent is American or British? I literally can't tell wtf

[@steveallen1635]

His accent is English but has very slightly been adulterated with an American slant, presumably by him living in California.

[@wyeth1023]

get Hofstadter on :)

[@JerseyLynne]

Electric Universe Theory! If misinterpretation of the red shift has occurred, would cosmologists ever admit it? And how far down the wrong path will you go? Make up dark matter to try and balance the equations. Or neutron stars? Dr. Carroll, if you read this comment, can you possibly give this a unbiased review, or does it just get your dander up?

[@michaelleahy3890]

Brooklyn isn't expanding!

[@wyeth1023]

Bosonic!

[@citizenscriv]

Had high hopes for this episode when I saw the title, unfortunately could not follow much of it all - please could Sean revisit the subject with Brian Greene ? as he is a much better communicator than this guest

[@stevescott200]

are you a string theorist? no I'm afraid not.