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Wednesday, February 09, 2011
A Peek Inside the Perimeter Institute
I almost forgot! Last year, the Canadian Association of Physicists' journal "Physics in Canada" published an issue on Perimeter Institute with a preface by Neil Turok and Rob Myers, and feature articles by PI researchers from all groups. It appeared during the summer, but then it took several months for the articles to appear online, by which time I was distracted by other things and forgot to tell you about it. The articles cover a great selection of topics on a level comparable to that of Physics Today. There is for example Alex Buchel et al on AdS/CFT and the Quark Gluon Plasma, Urbasi Sinha et al on an experiment testing Born's rule (which we previously discussed here), Willam Unruh on Analog Gravity and Black Holes, and Lucien Hardy and Rob Spekkens on Why Physics Needs Quantum Foundations. Just to mention a few. You find all the articles in PDF form here. It's very recommendable - enjoy!
28 comments:
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Thanks for this Bee. It's always good to get a peek inside any Institute for Advanced Study, as that's where the best speculative work is being done, eh?
ReplyDeleteBtw, what are the most respected ones? I profess ignorance, alas. I can only think of 5, in alphabetical order:
- Dublin
- Institute for Advanced Study, Princeton
- Niels Bohr Institute, formerly: Copenhagen
- Nordita
- Perimeter Institute for Advanced Study
I'm sure that's not a complete list, I'm just going by those that keep popping up in Science articles. I'm sure Japan and China have more than a few.
As far as distractions go, expect those "other things" to distract more and more as the next 20 years go on.
Finding the time to work AND parent is impossible; such time must be made. A challenge, to be sure, but a manageable one. I'm sure you'll manage fine, and frankly we're happy you've found time to pay any attention to this blog whatsoever.
Well, there's always Stefan. What's he up to now? What's new in Heavy Ion physics, new Daddy?
An amusing hybrid of names of institutes, Steve. The Perimeter Institute is also known as the Perimeter Institute for Theoretical Physics. I assure you that the only real Institute for Advanced Studies is located in Princeton, New Jersey.
ReplyDeleteOne ordinarily surmises theory models observation. Here we learn physics' agenda is the contrapositive. Think of the money saved! Theorists now only require pencil (pen!) and paper. Trash cans can be folded into themselves and discarded, er, recycled.
ReplyDeleteLuboš Motl wrote:
ReplyDeleteThe Perimeter Institute is also known as the Perimeter Institute for Theoretical Physics. I assure you that the only real Institute for Advanced Studies is located in Princeton, New Jersey.
Why thank you Lubos, my bad. Or we can call it the Lazaridis/Smolin Institute, in which case IAS-Princeton Township should be called Bamberger/Einstein. Works for me.
Oh! I forgot Kavli! My bad. We musn't forget David Gross and Joe Polchinski. So let's redo, and I'm always looking to expand this list:
- Dublin Institute for Advanced Studies
- Institute for Advanced Study, Princeton
- Kavli Institute for Theoretical Physics
- Niels Bohr Institute, formerly: Copenhagen
- Nordic Institute for Theoretical Physics (NORDITA)
- Perimeter Institute for Theoretical Physics
Lubos likes IAS-Princeton because it's String Theory Central, non-Anthropic Division. Everyone's entitled to their opinion, right Lubos?
Bee, well I read the article you coauthored with Lee. Very interesting. A lot of good ideas for future phenomenological observations of quantum gravity.The talk seems to have died down in recent months about DSR. Do you still actively pursue that trail?
ReplyDeleteThere seems to be two phenomenological approaches to quantum gravity:
1. Pursue high energy changes to relativity, such as time being discrete from space at extremely high energies.
2. Pursue low energy distortions of classical quantum mechanics at very large cosmological scales.
Personally I think the second may be easier to pursue simply because we now exist in a low energy density environment and one doesn't have be so lucky to find high energy events. I think this might be a very profitable place to look. Dark matter is obviously a contender here.
@2 is definitely the easier of the two and we're getting the data now from the great astronomical satellites especially Fermi and the earth-born observatories. It's called quantum cosmology and we've known about it since Lee Smolin's last book or was it the one before that? Invented at Penn State by Martin Bojowold as loop quantum cosmology, yes?
ReplyDelete"2. Pursue low energy distortions of classical quantum mechanics at very large cosmological scales."
ReplyDeleteMake that : Pursue low energy "analogues" of classical quantum mechanics at very large cosmological scales.
Agree. I didn't know they named a whole sector of cosmology after loop quantum gravity. Not sure, but i think that may be premature. Time will tell, unless of course it stops.
ReplyDeleteHi Steven,
ReplyDeleteI'm not much into rankings. There are btw several Kavli institutes (yes, the guy really had a lot of money). I guess you mean the one in Santa Barbara?
Regarding heavy ions, there was recently a brief review on the arxiv (a talk summary I suppose), it's only a few pages and will give you an impression what's going on, see 1012.4038. Best,
B.
Hi Eric,
ReplyDeleteYes, the article isn't only very brief, it's also somewhat outdated. This one is more comprehensive. It's not just high or low energy, it's also long distances or high precision, etc. Either way, the point is to reach some range in parameter space that hasn't been explored before.
It's not so much that I actively puruse DSR, as that DSR actively pursues me ;-) You know how it is. Once you've written a few papers on a topic you'll get papers for review, you'll get invitations for talks, you'll be asked for comment and feedback, etc. And then, when you're thinking about it anyway, you might have an idea for another paper. In any case, my prediction is that DSR will come back to haunt us in some altered version.
Best,
B.
Eric wrote:
ReplyDeleteAgree. I didn't know they named a whole sector of cosmology after loop quantum gravity. Not sure, but I think that may be premature.
I don't know either, that's why I asked, I'm just saying it was Lee Smolin's work that first alerted to me that the field even exists. It sounds a bit strange to look to the skies to examine the small. Then again QM is strange in its own right so, shrug, I dunno.
Oh and about Bee's Cosmic Strings stuff, I admit my bad, I didn't like that either because I made the huge mistake of thinking it has something to do with String Theory, which makes me see red (or used to, still does kinda, OK pink). CS is Cosmology, not a multi-dimensional speculative extension of QFT with alleged superpartners with names like wino.
Still ... Cosmology. Huh? It's a really young Science, and again in one of Lee's books he questioned if it's a "real" science. I guess by "real" we mean testable?
The Encyclopedia Brittanica lists only 3 "natural", which I define as "hard", Sciences: Physics, Chemistry, and Astronomy. I'll stick to those for the time being.
Speaking of which, just got an article on my feed re Brian Greene speculating that parallel universes are inescapable. I'm off to read it hoping that yet again, some science journalist hasn't confused the work of Hugh Everett III's and David Deustch's with Alan Guth's/Lenny Susskind's.
Hi Bee, I don't want to rank them either, which is why I presented in Alphabetical order. The oldest is Copenhagen/Bohr, right? Or The Swiss Patent Office of Stealing Time From Your Day Job To Change the World? Or The Galilean Leaning Tower of Pisa Feather Falling Proving Grounds? Or The Cambridge Apple Grove? Or Sandia?
I meant Kavli where Gross and Polchinski work, thanks, I didn't know there were several.
At least the article "Reviving Gravity's Aether in Einstein's Universe
ReplyDelete" (ArXiv preprint) is the step of the right direction....
Hi Bee,
ReplyDeleteThanks so much for this posting pointing out this grouping of articles surrounding the current research and programs which encompass the PI mission. I particularly enjoyed the piece written by Hardy and Spekkens entitled "Why Physics Needs Quantum Foundations" . I am indeed pleased that PI has over time developed a department to accommodate such research and not just have it left to a few brave souls to pursue in their spare time and often at the risk of being considered crack pots with those including the likes of Einstein, Bohm, J.S. Bell, Everett and Valentini being just a few examples.
That is I fully agree with their thinking that the current endeavours in Quantum information science is now really having the rubber meet the road in such respect. However most of all I like what they said in regards to the overall perspective, where the divide between “operationalists” and “realists” needing to be taken down as to recognize that such thinking never works well in exclusion, yet rather are complementary to one another; and necessarily so if sustained and meaningful progress in physics is to ever hoped be had.
“We should not expect that quantum information theory will be the only substantial application of ideas from quantum foundations. They may play a significant role in the construction of a theory of quantum gravity. They may even spawn entirely new fields of research that we cannot currently predict. Thinking about foundations pays off in the long run. David Mermin summerized a popular attitude towards quantum theory as “Shut up and calculate!”. We suggest a different slogan: “Shut up and contemplate!”.
-Lucien Hardy & Robert Spekkens,” Why Physics Needs Quantum Foundations”, Physics in Canada / Vol.66, No.2 (Apr-June 2010)
Best,
Phil
Yes thanks also Bee,
ReplyDeleteOne can be indeed attracted to that which most is appealing toward directions in research, about the beginnings of the universe. It is allowing one to coordinate perspective alongside of that which is most phenomenological followed, according to experimental research and predictability.
So you builds on that....while it is nice indeed to see the foundational attributes and position of our science leaders. It helped to orientate my perspective I can have about them in their science as I've trail alongside over the years. Nice indeed an open informational system that speaks to all generations.
Just trying to get exactly what their saying takes a long time.
One has to proceed as if one is a tracker inspecting the impressions in footsteps left about that foundational perspective. Which direction the lead. For me "about Lee and measure in time" as if he were tightly constraint around Fermi in measure. What I had often spoken of Glast in calorimeter measures.
We do not judge personally, or, the research method in which they have adopted according to the foundational perspective they may have garnered from my perspective. It's just not polite. It should be more toward the respect that would go a long way toward understanding that "silent perspective" about what we can learn from them, without voicing an opinion about so and so, or, that method.
A lot of us do not qualify to speak in such ways. So it can indeed be pleasant as one finds that what they had been following as an idea for a long time, has some basis in which one couched all that they have said had always been spoken in "couched words."
If they were the same in terms of temperatures in relation to viscosity then what dynamics would be most appealing in description toward entering ideas about the forming of the universe?
Best,
Hi Bee,
ReplyDeleteI reread your paper that you referenced as an update. It often takes several readings for me to fully latch onto the important things. This was also one of those times.
The first problem you mentioned in quantum gravity, though not necessarily the most important of the three, was the problem of quantum superposition. The Schroedinger Cat problem. I think of the three problems you mentioned this most directly relates to the theme of the first half of the paper, violation of Lorentz Invariance.
I personally think that those two things are very closely connected. An example from our every day experience: if we stand by the side of the road and a large truck passes by we experience the effect of frame dragging of the atmosphere by the truck. The truck has already passed us but we experience wind afterwards for a short time because in close proximity to the truck the reference frame of the atmosphere follows the truck. There does not seem to be any good reason to not apply this to the principle of frame dragging in GR. Frame dragging, contrary to popular understanding, seems to be a minor violation of Lorentz invariance.
I could be completely wrong, and I'm sure many would think I am, but it seems to me a lot of the problems of superposition have to do with frame dragging at the quantum scale. The vacuum really isn't empty and when a particle or body moves through it leaves an imprint. Just my own belief but the problem of Lorentz Invariance Violation reminded me that there is always a preferred frame in very close proximity of any particle. Your paper reinforced that belief somehow so I have to say it was good enough to stimulate some new thoughts.
Hi Eric,
ReplyDeleteWell, yes, frame dragging in GR is a violation of Lorenz-invariance, but of global Lorentz-invariance, not local one (no frame dragging in empty space). If you want more or other sorts of frame dragging, I suppose you'd end up with something akin the Jacobson-Ether model. That a particle leaves an imprint in vacuum doesn't help you if you don't know what the vacuum is. That's more than a philosophical statement, it's the question what really is 'empty space' if you know that space on Planckian scales becomes a fuzzy notion. The problem then is, to use your suggestion to resolve the issue, you'd already need to know the answer. Best,
B.
Hi Bee,
ReplyDeleteYou are right that we would like to know better what the quantum vacuum is actually comprised of. But I don't think that has ever stopped physics from prognosticating in spite of that through its interaction with experiment.
I don't want to monopolize your time or energy but I do think that the double slit experiment shows evidence of frame dragging. This shows up in the space between the slits and the target where the particles seem to interact with one another even though the particles enter the space one at a time. A slowly disintegrating pathway seems to develop in the QV between the slits and the target that each subsequent particle coming through has an interference with.
But this is off the subject of your article so I won't take any more of your time.
Hi Igor,
ReplyDeleteThanks, fixed that typo. Hier kommt Alex! ;-) Best,
B.
Absolute determinism is one [very naive] thing.
ReplyDeleteThe determinism of nonlinear dynamical systems is quite another.
In the latter, what happens next is causally determined via an infinite tapestry of causal "chains", but not fully [often not even minimally] predictable.
Also, via trial/error/learning feedback loops an organism can change it's behavior, albeit slowly. Therefore determinism need not be viewed as "robotic" or inconsistent with morality.
When we discuss determinism, it is important to make these distinctions.
Hi Robert,
ReplyDeleteFree will and determinism are fundamentally incompatible. Without free will, moral is a farce. In case that's what you mean. I suppose you're referring to either my recent comment at CV or at NEW. Yes, an organism can change its behavior, but that change is also determined. And that it's determined isn't the same as it being predictable. I'm saying they are fundamentally incompatible because you could argue free will is existent in some sense as an emergent feature. (I meant to write a post on that topic at some point, but seems I haven't come around to do it.) Best,
B.
Hi Bee,
ReplyDeleteI get the feeling that we agree on these issues far more than we disagree.
My main concern is that concepts like "free will" and "determinism" come with a lot of baggage attached.
Therefore meaningful discussions of these topics require a careful definition of terms.
Personally, I think the traditional concept of unrestricted "free will" is incompatible with scientific evidence and is more wishful thinking than rational thinking.
"Determinism" is often treated with contempt by others, but this is mostly because they only consider a very rigid definition.
I think we may agree that there is a more enlightened form of determinism that is supported by scientific evidence, is consistent with most of our theoretical knowledge, and does not imply that humans are hard-wired robots.
It is an interesting area for discussion, e.g., what is the relationship between causality and determinism?, and what constitutes a scientific definition of determinism?
Interesting discussion at CV!
RLO
Bee and Robert,
ReplyDeleteI think one could apply the fact that self organization of discete structures into complex cooperating organisms a kind of determinism. It seems to happen at every level of structure without the individual entities making an "effort".
These overall structures are a web of interdependencies between the "cooperating" entities.
If one looked at these cooperating structures as based similarly to asymptotic freedom it means we can act independently up to a point. But at the limit we have no ability to really disengage from the other. When I was saying in an earlier thread that I think strong coupling will lead to a more deterministic view of physics, that is what I meant. We are not allowed to completely disengage from one another. Frightening thought, huh!
This comment has been removed by the author.
ReplyDeleteAh so, since no one has answered my question of which of these Institutes came first, I answer my own question from an unexpected place, that being Euler's Gem" by Dave Richeson, to whit:
ReplyDelete1660 - The Royal Society of London
also 1660 - The Academie des Sciences in Paris
1700- The Berlin Academy of Sciences (on the advice of Leibniz)
1725 - The Russian Academy of Sciences in St. Petersburg (with a mostly German professorship, and Euler and the Bernoulli brothers)
So, how are those places doing today?
Hi Steven,
ReplyDeleteAs far as I know the oldest of them all was The Academy, that is the one started by Plato in 387 BC in Athens, with Aristotle as one of his first graduate students:-) Unfortunately the Romans destroyed it in 83 B.C. with no permanent replacement until 410 AD. However this also finally closed under the order of Emperor Justinian in 529 AD as there being room for only one philosophy ( I wonder what this has come to mind). Some of the knowledge and teachings survived after and became part of the foundation for the Arabic revival of the Neoplatonist commentary tradition in Baghdad. In the meantime Europe descends into the dark ages.
Best,
Phil
Yes, I know Phil, and Aristotle's Lyceum as well. Unfortunately, all kinds of bad history went down between them and the age of Humanism (The European Renaissance, 1400's and 1500's), and then thanks to the Borgias screwing up Europe to the point that Lutherism and Calvinism launched and thus the whole embarrassing Catholic/Protestant stupid beatshit wars rendered the 1600's relatively moot, here came the 1700's and enlightenment and the re-birth of that which Plato and Aristotle so lovingly began.
ReplyDeleteHi Robert,
ReplyDeleteYes, it requires definitions of terminology before one can make statements. What I mean with determinism is that there's a one-to-one map from states at time t_1 to t_2 for all t_1 and t_2. What I mean with free will on a fundamental level is that at some time t_1 what you will be doing in the future at t_2 is not inevitably fixed already (so you can 'freely' choose what to do). That's evidently incompatible with determinism. One could argue though there's some sort of emergent free will in that what a system, S, that is a subsystem of a larger system we can call the universe, will do at t_2 is not determined by the state of the system S at t_1. Basically that means that S can continue to gather information and 'learn' etc. On a subjective level you could call that free will. In any case, the neurological basis of free will is yet another story and one that I don't know very much about. Best,
B.
Hi Robert & Bee,
ReplyDeleteFrom my own perspective “free will” is a concept only assignable to consciousness, while irrelevant in any other respect. That is nature doesn’t recognize paths or options, it only executes, as having consciousness alone as able to recognize alternatives. When it comes to causation and determination there is a distinction to be drawn between outcomes absent of intent as opposed to being resultant of them.
Best,
Phil