## Saturday, October 18, 2014

### ETs, hippies, loons introduce Andrew Strominger

...or a yogi and another nude man?

Exactly one week ago, Andrew Strominger of Harvard gave a Science and Cocktails talk in Christiania – a neighborhood of Copenhagen, Denmark.

The beginning of this 64-minute lecture on "Black Holes, String Theory and the Fundamental Laws of Nature" is rather extraordinary and if you only want to see the weirdest introduction of a fresh winner of the Dirac Medal, just listen to the first three minutes of the video.

However, you will obviously be much more spiritually enriched if you continue to watch for another hour – even though some people who have seen similar popular talks by Andy may feel that some of the content is redundant and similar to what they have heard.

After the introduction, you may appreciate how serious and credible Andy's and Andy daughter's illustrations are (sorry, I can't distinguish these two artists!) in comparison with the mainstream culture in the Danish capital.

At the beginning, Andy said that it's incredible how much we already know about the Universe. We may design a space probe and land it on Mars and predict the landing within a second. We are even able to feed roast beef to Andrew Strominger and make him talk as a consequence of the food, and even predict that he would talk.

It's equally shocking when we may find something clear we don't understand – something that looks like a contradiction. Such paradoxes have been essential in the history of physics. Einstein was thinking what he would see in the mirror if he were running by the speed of light (or faster than that) and looking at his image in the mirror in front of him. Newton's and Maxwell's theories gave different answers. Einstein was bothered by that.

The puzzle was solved... there is a universal speed limit, special relativity, and all this stuff. About 6 other steps in physics are presented as resolutions to paradoxes of similar types. If we don't understand, it's not a problem: it's an opportunity.

Soon afterwards, Andy focuses on general relativity, spacetime curvature etc. The parabolic trajectories of freely falling objects are actually the straigh(est) lines in the curved spacetime. After a few words, he gets to the uncertainty principle and also emphasizes that everything has to be subject to the principle – it's not possible to give "exceptions" to anyone. And the principle has to apply to the space's geometry, too.

There is a cookbook how to "directly quantize" any theory, and this procedure is amazingly tested. If you apply the cookbook to gravity, GR, you get carbagan which is great because it's a lot of fun. ;-) He says we will need "time" to figure out whether the solution we have, string theory, is right in Nature. However, already now, some more basic Harvard courses have to be fixed by some insights from the string course.

Suddenly he mentions Hawking and Bekenstein's ideas about black holes. What do black holes have to do with these issues? They have everything to do with them, it surprisingly turns out. An introduction to black holes follows. Lots of matter, escape velocity, surpasses the speed of light – the basic logic of this introduction is identical to my basic school talk in the mountains a few months ago. ;-) The talks would remain identical even when Andy talks about the ability of Karl Schwarzschild to exactly solve Einstein's equations that Einstein considered unsolvably difficult. Einstein had doubts about the existence of the black holes for quite some time but in the 1960s, the confusion disappeared. Sgr A* is his (and my) key example of a real-world black hole.

Andy says that there's less than nothing, namely nothing nothing, inside black holes. I am not 100% sure what he actually means by that. Probably some topological issues – the Euclidean black hole has no geometry for $$r\lt r_0$$ at all. OK, what happens in the quantum world? Particles tunnel out of the nothing nothing and stuff comes out as the black body radiation – at Hawking's temperature. Andy calls this single equation for the temperature "the Hawking's contribution to science" which slightly belittles Hawking and it's surely partly Andy's goal but OK.

He switches to thermodynamics, the science done by those people who were playing with water and fire and the boiling point of carbon dioxide without knowing about molecules. Ludwig Boltzmann beautifully derived those phenomenologically found laws from the assumption that matter is composed of molecules that may be traced using the probabilistic reasoning. He found the important of the entropy/information. Andy wisely presents entropy to be in the units of kilobytes or gigabytes - because that's what ordinary people sort of know today.

Andy counts the Hawking-Bekenstein entropy formula among the five most fundamental formulae in physics, and perhaps the most interesting one because we don't understand. That's a bit bizarre because whenever I was telling him about the general derivations of this formula I was working on, aside from other things, Andy would tell me that we didn't need such a derivation! ;-)

Amusingly and cleverly, he explains the holographic entropy bounds by talking about the Moore's law (thanks, Luke) that must inevitably break down at some point. Of course, in the real world, it will break down long before that... Now, he faces the tension between two pictures of black holes: something with the "nothing nothing" inside; or the most complicated (highest-entropy) objects we may have.

Around 41:00, he begins to talk about string theory, its brief history, and its picture of elementary particles. On paper, string theory is capable of unifying all the forces as well as QM with GR, and it addresses the black hole puzzle. String theory has grown by having eaten almost all the competitors (a picture of a hungry boy eating some trucks, of course). The term "string theory" is used for the big body of knowledge even today.

I think that at this point, he's explaining the Strominger-Vafa paper – and its followups – although the overly popular language makes me "slightly" uncertain about that. But soon, he switches to a much newer topic, his and his collaborators' analysis of the holographic dual of the rotating Kerr black holes.

Andy doesn't fail to mention that without seeing and absorbing the mathematics, the beauty of the story is as incomplete as someone's verbal story about his visit to the Grand Canyon whose pictures can't be seen by the recipient of the story. The equation-based description of these insights is much more beautiful for the theoretical physicists than the Grand Canyon. Hooray.

Intense applause.

Last nine minutes are dedicated to questions.

The first question is not terribly original and you could guess that. What kind of experiments can we make to decide whether string theory is correct? Andy says that the question is analogous to the question to Magellan when he's in the middle of his trip around the Earth, when will he complete the trip? We don't know what comes next.

Now, I exploded in laughter because Andy's wording of this idea almost exactly mimics what I am often saying in such contexts. "You know, the understanding of Nature isn't a five-year plan." Of course, I like to say such a thing because 1) I was sort of fighting against the planned economy and similar excesses already as a child, 2) some people, most notably Lee Smolin, openly claimed that they think that science should be done according to five-year plans. It's great that Andy sees it identically. We surely don't have a proposal for an experiment that could say Yes or No but we work with things that are accessible and not just dreamed about, Andy says, and the work on the black hole puzzle is therefore such an important part of the research.

The second question was so great that one might even conjecture that the author knew something about the answer: Why does the entropy and the bounds scale like the area and not the volume? So Andy says that the black hole doesn't really have the volume. We "can't articulate it well" – he slightly looks like he is struggling and desperately avoiding the word "holography" for reasons I don't fully understand. OK, now he said the word.

In the third question, a girl asks how someone figured out that there should be black holes. Andy says that physicists solve things in baby steps or smaller ones. Well, they first try to solve everything exactly and they usually fail. So they try to find special solutions and Schwarzschild did find one. Amazingly, it took decades to understand what the solution meant. Every wrong thing has been tried before the right thing was arrived at.

Is a black hole needed for every galaxy? Is a black hole everywhere? He thinks that it is an empirical question. Andy says that he doesn't have an educated guess himself. Astronomers tend to believe that a black hole is in every galaxy. Of course, I would say that this question depends on the definition of a galaxy. The "galaxies" without a black hole inside are probably low-density "galaxies", and one may very well say that such diluted ensembles don't deserve the name "galaxy".

In twenty years, Andy will be able to answer the question – which he wouldn't promise for the "egg or chicken first" question.

I didn't understand the last question about some character of string theory. Andy answered that string theory will be able to explain that, whatever "that" means. ;-)

Another intense applause with colorful lights. Extraterrestrial sounds conclude the talk.

1. Andy is the best at explaining the frontier of our knowledge to non-technical people, isn’t he?

2. Science is failing as it has to invent more rabbits to pull out of the hat than it can afford to feed.

To name a few - dark matte, dark energy, inflation, axions, vacuum energy density, critical cancelation of divergent high energy ferms, sterile neuts,....

In fact the rabits are sterile but some how they are having virtual bunnies , about 10^500 of them.

3. Dear Svik, do you have some evidence supporting any of the bold claims you are making, e.g. your bold claim that at least one of the "bunnies" is wrong in Nature?

4. He's excellent at that but he is really a top expert in this QG stuff, you realize that, Gene, right?

5. Are you joking or trolling ... ;-)?

6. Just the sober truth with a smile.

7. Dark matter may be real but its no sure thing. There is a counter example to the bullet cluster. It id just so wimpy to invent another rabbit every time there un explained observations. At least figure out the properties of this stuff first.

Inflation is needed for uniformity. Maybe it's real or maybe there is another mechanism. Try dreaming up another explanation.

Same thing with axioms. Invented to avoid critical cancelation. But no sign of it yet.

Somehow everything in the universe is critically balanced and very optimized. Many theories are inventednto avoid this fact...

8. Of course I do.

9. I see ...

But TRF is a physics blog and not a platform for promoting your personal "truth" or more appropriately dislike and hate of modern physics. For selling your "truth" you can go the 10^1000 of webpages populated by similar minded trolls devoted to rant about fundamental physics.

Too bad, I once thought you are a rather cool reasonable person.

I still sourly miss the downvote button :-/

10. I know what you mean. I miss it too.

One clamours for proper feedback.

And even to give it on occasion. :)

11. The fact that science despite its successes can't give a satisfactory explanation of many things including the items listed below shows that it is incomplete and has failed in that area.

This is humbling to most scientists and makes one appreciate the universe we live in. And there is room for more work to be done. New theories to discover which will change the way people thing just like qt and relativity does.

I like science but don't worship it.

Have you done any computation at all??

12. "ETs, ex-hippies, loons introduce Andrew Strominger"
Hmmm, I didn't recognize Lee Smolin in the intro--my attention must have been wandering :)

13. Dear Dilaton, there *is* a downvote button here - it's the "v"-shaped thing between "^" and "Reply". The system just doesn't show the number of downvotes and who gave them, not even when you try to find out. ;-)

14. Dear Bernd, scientists are not only allowed to be wrong. Being wrong is an essential piece of being science.

Among similar papers, a majority clearly turns out to be wrong as a discovery of a new effect. But I am interested in physics and this is a physics blog that writes about these advances - in more detail than any other personally owned website in this world - so of course that I have to write about work that remains uncertain.

If I were only writing about things that are certain and completely established, I would only be writing about things that were really found decades ago.

15. Dear John, the Pontryagin duality etc. is hard and the background is nontrivial. It is no illusion.

Lie groups etc. are simpler, more basic piece of mathematics. I've learned lots of group theory etc. etc. from many places including English, Czech, and Russian books, courses, papers, and especially self-learning. It's hard to put it together. You may surely find lots of good books and similar sources about group theory.

16. Well if one just blindly believe every theory that comes along then it is a political movement like the brown shirts.

I dont see what the problem is. The scientist I have worked with appreciate a critical test of the theory or calculation results.

It better to find the problems before publishing it.

17. A group that can't take any critism is a cult.

And it has only been less than one day.

Well I guess being roasted by you is an honour.

Thanks.

My keyboard mixes up n's with m's. That is what happen when using a cell phone.

I thought my dark matter is whimpy comment was a little funny at least. :-(

If you or anyone reading this comes to waterloo I'll get you a free port hock dinner. Just email s.vik at hot mail.

Bye bye

18. Seems you now reveal your true colors and mind setting ...

Your comments below this article are exact duplicates of the agressive rubish and nonsense one finds below popular wannabe news articles about fundamental physics or in science hate blogs for example or even in not properly moderated better physics blogs. A

nd you have quite a number of cracpot points on John Beaz crackpot index from claiming that legitimate physics is religion, good physicists ar nazis, etc ...

I hope Lumo puts you on the black list soon, such that we are no longer bothered by your low-level agressive trolling here ...

19. Dear Svik, I don't know if you couldn't read English or because you wanted it, but you're banned after this "brown shirt" comment as I told you in advance.

Please if you ever want to be removed from the black list, don't contact me before 2015.

20. Dear Dilaton, it took about 5 minutes from your hopeful comment - a good and accurate prediction of yours! ;-) But given Svik's insufferable trolling in recent 24 hours, it wasn't such a hard prediction to be made, right? ;-)

21. Which premise is false and irrational?

Perhaps I was cryptic in my last message, but you may recognise contribute what they can, take what they need as a paraphrasing of "from each according to his ability, to each according to his need"

22. I completely dismiss any movement that wants to change the english language to suit themselves. Feminists use the term 'wimmin' because they don't want 'man' inside 'woman'. I'll leave the smart-arse comments upto you. I thought it was a stupid spelling mistake from some dumbshit and was highly amused. A feminist aquaintance corrected my error. My eyes rolled into the back of my head and I was left speachless, for once in my life.

23. I think Lubos likes to bait andrew.

24. Precisely!

25. marx couldn't have phrased it any better than you just did..perhaps that is because you just stole that quote from marx.
so...my idea of a fair society is one where people can't steal other peoples' thoughts and words without attribution. you sir are a plagiarist.

26. thief.

27. Exactly precisely! :)

These idiot maniacs have now had four whole centuries to learn that COMMUNISM KILLS and still they keep coming.

It's high time to give up on this level of retardism — it's giving even pisslam a run for its money.

I recommend the same treatment as that given to the smallpox virus.

28. Feminism, racism and all the other isms are not about equality. They are about 'turning the table' and making the alleged underdog superior. Societal changes take time. In my first voting experience in Australia when I was 18 I 'gave' normal citizenship to aboriginal people. I couldn't comprehend how it was possible for one human being to be 'less' than another. I didn't need rabid marchers to convince me of that. It was commonsense. I didn't know about this inequality until I was told. No-one needed to ram these ideas down my throat.

29. John - andrew and his ilk are living a life of parasitic luxury which
will come to an end as the host either dies or develops immunity.
Sadly, it seems unlikely that an effort to eradicate this nonsense will
get underway anytime soon.
Of course, if history is any guide, should andrew get what he wants he'll be one of the first up against the wall, etc.
So there is some small consolation.

30. I think this thread highlights the trouble with discussions on internet forums - a lack of discipline. We've jumped from the feminism paradox, to feminism, to Cuba, socialism, Marx, nihilism, plagiarism (?!) and now a link about the pilgrims, all peppered with menacing insults.

If I do comment on e.g. whether I plagiarised Marx or whether socialism failed the pilgrims, I'm convinced the discussion would take another Knight's move to other major topics.

I stand before you - a living, breathing socialist - expounding feminism in a right-wing, hostile environm cultivated by the supposed great intellect of Lubos Motl, but I face no engaging, well-structured rebuttals. Only bitter, malicious remarks or undisciplined, ill-informed rants.

This site, especially below the comment line, isn't a place of deep, high-level thought. It's a den of the intellectual detritus of the past millennia and a motley crew who treasure it.

31. You're pretty young, aren't you? It shows.

Your muddled crap isn't even worth the rebuttal. You're all over the place. Hence my lack of response to your later replies above.

It does provide some light comedy though.

First we get this:
"... I face no engaging, well-structured rebuttals. Only bitter, malicious remarks or undisciplined, ill-informed rants."

Only to be followed shortly by this:
"This site ... is a den of the intellectual detritus of the past millennia and a motley crew who treasure it."

Very good. :)

People like you paint themselves as great philanthropists. You're nothing of the kind. It's ALL about YOU, and only YOU. All ego and ostentation. Otherwise you're empty. I know your kind well.

32. Living, breathing socialists are the intellectual detritus as your lack of discipline demonstrates. All these 'diversions' came from your otherwise empty head.
You should stay at home Princess, where men can protect you.

33. Your keyboard cannot be blamed, Svic. If you don’t have the simple courtesy to proofread your contributions you should not make them.
Only fools fail to admit their shortcomings and Lubos is far more fool-tolerant than am I

34. You, my friend, are unmatched at explaining things to competent but obsolete physicists such as myself. It would be wonderful to see you teach such things to Isaac Newton, the most competent physicist of all. You would find him a fast learner.
I also think you could give Andy a run for his money with the non-technical crowd.

35. Thanks, Gene, you're beloved.

Meeting Isaac Newton and chat about the progress that occurred after his death was always among my impossible dreams. I sort of think that he could be really excited - more than people are today - and appreciate it. But I may be wrong, too. Einstein wasn't excited by the quantum revolution. Could Newton have had similar limitations that would prohibit him from learning modern physics?

36. Thanks for your answers. You see I have this ambivalence when it comes to learning mathematics. I think if some mathematics is used in nature it is part of physics therefore I should really understand it. Most of graduate levels mathematics textbooks are incomprehensible for me, because they are using very abstract language, categories etc. I mean bourbaki style is now everywhere. Of course mathematicians are free to do everything as they like. But I believe mathematical education of physicists should improve significantly. I don't really think that school education is enough to prepare students to tackle really profound mathematical problems in modern theoretical physics. I am studying Nakahara's book now, however I really wonder whether this style of learning really prepares you to discover new mathematics yourself. Of course leading theoretical physicists are very bright and they can manage it but probably they would gain a few years if some skills were given in school.

37. This is also noted in the article, but they say the model for predicting the seasonal variations has several known limitations. So it not so important how well they can predict the seasonal variations - more important is that there are seasonal variations at all.See table 3.

38. errata? Morse law = Moore's law

39. Andy doesn't fail to mention that without seeing and absorbing the mathematics, the beauty of the story is as incomplete as someone's verbal story about his visit to the Grand Canyon whose pictures can't be seen by the recipient of the story.

Beautiful analogy

40. OT, but my six-year-daughter answered "the "egg or chicken first" question" correctly, I think. She said the egg. And since mutations -- the ones that can be passed on -- must occur in the germ plasm, the egg must have preceded the new kind of bird. I think that was only a puzzle before modern genetics.

41. Didn't Mach speculate about something similar -- that rotation can only exist in relation to all the stars in the firmament? And since Einstein postulated that inertial mass and gravitational mass are equivalent, wouldn't this imply that inertia also only exists because of all the other matter in the universe creating a gravitational field throughout space?

I guess Archer and I are both amateurs.

42. Could Newton have had similar limitations that would prohibit him from learning modern physics?

He would have to jettison his alchemical ideas and beliefs.

43. Thanks, Luke, fixed and thanked.

44. In some sense, you may be right. The whole "advanced stages" of the evolution of an individual animal only appeared when life became more sophisticated - while all of the early life was in the form of "eggs" (or even more primitive forms).

You may also divide the life cycle of the primitive organism so that you still call the organisms in latter parts of their lives "chicken" even if they were much more spherical etc. Then the answer is as uncertain as usually said.

45. A bit of trivia concerning the intro: the "ET, hippie, loon" is a actually a theorist himself http://www.itp.unibe.ch/people/personal-page.html?uid=96

46. Thanks for the information, Lewis. The text had clearly been written by an expert but I thought that they had to hire an artist to perform it - and it looked like 2-3 artists similar to this Russian one

http://www.ryot.org/naked-russian-artist-pulls-van-gough-cutting-ear-political-protest/845817

who hanged himself by his balls and cut his ear - a similar kind of art.

47. Lubos,
My points are the following:
(a) If it's make in the Sun, then it can't be dark matter. Part of the point of dark matter is to explain why the universe was lumpy while the CMB was being formed. If axions can be created in the Sun and then interact with magnetic fields, then this is not the same dark matter that is required to explain the lumpiness in the CMB. Dark matter can't interact with normal matter unless the temperature of the medium is in the GeV or higher.
(b) The Sun makes all sorts of particles of keV to MeV energy scale, so it's not shocking that there is a seasonal dependence of X-rays measurements by satellites.
(c) The jump between X-rays and axions is a huge jump, with many other possible explanations for the seasonal dependence of the X-ray signal.
As such, this is complete hype and should be treated as nothing more than a seasonal dependence in the measurement of X-rays.

It is your post that was nonsense because you don't seem to recognize Dark Matter can't interact with magnetic fields and still be called dark matter.

48. Sorry, rubbish 3 times.

a) there is nothing wrong if dark matter may be produced in the Sun. *Every* particle species with nonzero interactions is created at sufficiently high temperatures with a nonzero probability.

The dark matter particle may be around in the clouds in the Milky Way but it may also be created in the stars. Carbon dioxide is produced by burning fossil fuels which doesn't mean that it's not the same compound as the compound that all green plants need for growth. At the end, these two things are linked because the coal is nothing else than processed plants that were once growing.

You probably confused axions with WIMP when you quoted the GeV scale. GeV scale plays no special role for axions - those are associated mostly with much lower scales.

b) You haven't actually given any reason for the seasonal variation.

c) The jump between axions and X-rays may be described by any adjective such as "huge" or whatever but the Primakoff effect is a well-established experimentally proven mechanism producing mesons and the corresponding mechanisms converting or producing axions are minor analogies of this effect and the other one.