Slashdot Mirror
The Trouble with Physics
SpaceAdmiral writes "You've likely heard of Lee Smolin's book The Trouble with Physics. It has created a lot of controversy because it argues that string theory gets far too much attention and money, despite a complete lack of evidence. It accuses string theorists of groupthink. Smolin has dabbled in string theory from time to time but he's a proponent of the alternative loop quantum gravity. Although irrelevant to this book review, he has also suggested that it is possible that universes reproduce via black holes, making them prone to pressure similar to natural selection (universes that produce a lot of black holes are more successful spawners than those that don't). In The God Delusion, Richard Dawkins quotes Nobel-winner Murray Gell-Mann as once saying, "Smolin? Is he that young guy with those crazy ideas? He may not be wrong."" Read the rest of SpaceAdmiral's review.
The Trouble with Physics
author
Lee Smolin
pages
392pp
publisher
Houghton Mifflin Company
rating
9
reviewer
Fane Henderson
ISBN
0618551050
summary
The Rise of String Theory, the Fall of a Science, and What Comes Next
The Trouble with Physics is very unlike most pop-physics books not only in its criticism of string theory, but in its open adulation of Einstein and skepticism of the Copenhagen interpretation of quantum theory. Having said that, it does provide a very decent summary of 20th century physics (including string theory) for laypeople, not unlike more traditional pop-physics books (e.g. by Hawking and Greene).
The book's main criticisms of string theory are that it makes no testable predictions and that some things string theorists take for granted haven't been rigorously proven mathematically. Smolin is highly skeptical of many string theorists' reliance on the Anthropomorphic Principle.
The book becomes most interesting somewhere in the middle where he discuses truly controversial approaches to physics. This includes things like MOND, which, interestingly enough, Smolin is skeptical of.
In case you've forgotten your high-school physics, I'm going to use this paragraph to refresh your memory of special relativity to prepare you for the next couple paragraphs. The basic idea of special relativity is that the speed of light is constant. Pretend that I am shining a light at you while (A) standing still relative to you; (B) moving towards you at half the speed of light, and; (C) moving away from you at half the speed of light. In all three scenarios, I will accurately measure the light moving away from me at 3,000,000 km/s and you will accurately measure the light moving toward you at 3,000,000 km/s. To ensure this result, distances and times will have to be different for me than they are for you, except in case (A).
Now I'll quickly remind you of the Planck length: This is a theoretical limit on how small something can be. According to Smolin, all versions of quantum gravity seem to suggest the Planck length as a limit. But would observers moving relative to each other disagree about the Planck length?
I used to be a big fan of MOND (in a layperson sense) until Smolin introduced me to DSR (doubly special relativity) and DSR II. The basic idea is that it may be possible to modify the theories of relativity such that observers agree not only on a constant speed of light, but also on a constant Planck length. It's not unreasonable to guess that a modification of this sort could solve some of the same problems MOND does (e.g. explain astronomical observations without resorting to dark matter and dark energy). Furthermore, since DSR in its current incarnation predicts that more energetic photons are slightly faster than less energetic photons (only the speed of the least energetic photons is constant in DSR), it could also explain away, for example, inflation in the Big Bang model. (Immediately after the Big Bang, everything was hotter and more energetic, so the average speed of light would have been faster than it is now if DSR is correct.) Although I'm not qualified to judge the actual mathematics of such a theory, I find it very appealing for reasons of consilience.
I was slightly disappointed with the final chapters of Smolin's book since, despite an obvious effort to the contrary, it struck me as awfully bitter and reeked of sour grapes. Leaving physics in favor of sociology, he lambasted the current tenure and peer review systems (particularly in the United States) as favoring Master Craftspeople (like those scientists who developed the standard model of particle physics) over Seers (like Einstein, Bohr, and de Broglie) who look at the deep questions of physics that border on the philosophical rather than the latest technical problem. A few interesting things do emerge in these chapters. One such thing is that Smolin seems to have a soft spot for Paul Feyerabend as a philosopher of science (despite describing himself as a proud Popperazzo in an endnote). Another is that Smolin thinks a scientist who is hated by half his senior colleagues and loved by the other half is likely better than a scientist who is liked by all his senior colleagues. I strongly recommend this book.
You can purchase The Trouble with Physics from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.
The Trouble with Physics is very unlike most pop-physics books not only in its criticism of string theory, but in its open adulation of Einstein and skepticism of the Copenhagen interpretation of quantum theory. Having said that, it does provide a very decent summary of 20th century physics (including string theory) for laypeople, not unlike more traditional pop-physics books (e.g. by Hawking and Greene).
The book's main criticisms of string theory are that it makes no testable predictions and that some things string theorists take for granted haven't been rigorously proven mathematically. Smolin is highly skeptical of many string theorists' reliance on the Anthropomorphic Principle.
The book becomes most interesting somewhere in the middle where he discuses truly controversial approaches to physics. This includes things like MOND, which, interestingly enough, Smolin is skeptical of.
In case you've forgotten your high-school physics, I'm going to use this paragraph to refresh your memory of special relativity to prepare you for the next couple paragraphs. The basic idea of special relativity is that the speed of light is constant. Pretend that I am shining a light at you while (A) standing still relative to you; (B) moving towards you at half the speed of light, and; (C) moving away from you at half the speed of light. In all three scenarios, I will accurately measure the light moving away from me at 3,000,000 km/s and you will accurately measure the light moving toward you at 3,000,000 km/s. To ensure this result, distances and times will have to be different for me than they are for you, except in case (A).
Now I'll quickly remind you of the Planck length: This is a theoretical limit on how small something can be. According to Smolin, all versions of quantum gravity seem to suggest the Planck length as a limit. But would observers moving relative to each other disagree about the Planck length?
I used to be a big fan of MOND (in a layperson sense) until Smolin introduced me to DSR (doubly special relativity) and DSR II. The basic idea is that it may be possible to modify the theories of relativity such that observers agree not only on a constant speed of light, but also on a constant Planck length. It's not unreasonable to guess that a modification of this sort could solve some of the same problems MOND does (e.g. explain astronomical observations without resorting to dark matter and dark energy). Furthermore, since DSR in its current incarnation predicts that more energetic photons are slightly faster than less energetic photons (only the speed of the least energetic photons is constant in DSR), it could also explain away, for example, inflation in the Big Bang model. (Immediately after the Big Bang, everything was hotter and more energetic, so the average speed of light would have been faster than it is now if DSR is correct.) Although I'm not qualified to judge the actual mathematics of such a theory, I find it very appealing for reasons of consilience.
I was slightly disappointed with the final chapters of Smolin's book since, despite an obvious effort to the contrary, it struck me as awfully bitter and reeked of sour grapes. Leaving physics in favor of sociology, he lambasted the current tenure and peer review systems (particularly in the United States) as favoring Master Craftspeople (like those scientists who developed the standard model of particle physics) over Seers (like Einstein, Bohr, and de Broglie) who look at the deep questions of physics that border on the philosophical rather than the latest technical problem. A few interesting things do emerge in these chapters. One such thing is that Smolin seems to have a soft spot for Paul Feyerabend as a philosopher of science (despite describing himself as a proud Popperazzo in an endnote). Another is that Smolin thinks a scientist who is hated by half his senior colleagues and loved by the other half is likely better than a scientist who is liked by all his senior colleagues. I strongly recommend this book.
You can purchase The Trouble with Physics from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.
I see two sides to this. Smolin has a point. Most string theory papers are garbage. (True of many fields). But Smolin himself has not been research active in a long time. And it is unlikely that he understands enough mathematics to judge string theory - like most people.
Nothing for you to see here. Please move along.
Although irrelevant to this book review, he has also suggested that it is possible that universes reproduce via black holes, making them prone to pressure similar to natural selection (universes that produce a lot of black holes are more successful spawners than those that don't). doesn't the same despite a complete lack of evidence quote apply to this just as well?
You can't handle the truth.
i've been scoffed at for a few years now for my layperson's mistrust of the Copenhagen Interpretation, and i'd love to have some weightier opinions to back me up. and who doesn't want to get rid of dark energy/matter and hyperinflation ? they reek of jerry-rigged fixes to a fundamentally flawed design.
Really? I didn't realize giving human characteristics to subatomic particles was a part of any current mainstream physics theory. :)
I'm assume you mean the *anthropic* principle.
Not very accurate. It should be 300,000 km/s. Or 299,792.458 km/s to be precise.
English is not this
I'd be interested to know what the Anthropomorphic principle was... the laws of the universe are structured such that man-shaped being have to exist, perhaps?
Smolin is research active, but I seriously doubt he understands what Ed Witten did in the 1990's, for example.
did he write this book using 12 sided dice and a lot of caffeine?
Support NYCountryLawyer RIAA vs People
Seastead this.
A quick search on arxiv.org will show you that he is indeed very active, since he is still publishing very technical papers.
...
Not only that, Lee Smolin seems one of the very very few physicists who understands BOTH string theory AND other approaches (that is _the_ other approach, loop quantum gravity).
In any case, it seems that many predictions of loop quantum gravity will be actually tested within the next couple of years trough the GLAST satellite, so, we will get news relatively soon
We learn from history that we learn nothing from history - Tom Veneziano
Why is it that suddenly people are working out ways to mention Dawkins in as many articles as they can that have little if nothing to do with him? Are we playing a six-degrees-to-Richard-Dawkins game here?
"Do not be swept up in the momentum of mediocrity." - anon
I used to be a big fan of MOND (in a layperson sense) until Smolin introduced me to DSR (doubly special relativity) and DSR II.
Personally, I've been a fan of Heim theory, not necessarily because I think it's definitely true even though it makes nice predictions about particle mass, but because I just really want a space drive to be possible.
If it's for-profit but free, you're not the customer -- you're the product (e.g., the Slashdot Beta's "audience").
There's an interesting article in the last issue of New Scientist, discussing work by physicist Gerard 't Hooft in refining his theory of a determanistic level of reality below quantum physiscs, from which the apparent randomness and Copenhagen state collape of quantum physics appears.
m g19025504.000
http://www.newscientist.com/channel/fundamentals/
Maybe Einstein was right that "God doesn't play dice" (a rather misunderstood statement given that Einstein was an ardent aetheist).
Presumably efforts such as string theory to unite general relativity & quantum mechanics may be quite shaken up if this new theory is correct.
A big problem amongst educated people is to think that scientists are not prone to the same illogical behavior as average people. We think that they are immune to "following the flock" or otherwise being influenced by their peers.
While scientists are in general better than average people at being objective, they still tend to have their own biases. Spending you life working on a particular theory makes it hard to give it up even when the evidence disproves it. Even an objective scientist is going to have problems throwing away their life's work.
--
-- All that is necessary for the triumph of evil is that good men do nothing. -- Edmund Burke
Vilenkin has published an interesting paper which suggests a problem with Smolin's "natural selection of life-friendly universes via black holes" theory; OTOH Smolin strikes back! Ahhh, I love it when cosmologists attack ;)
"None are more hopelessly enslaved than those who falsely believe they are free." -- Goethe
OK, so he has a paper on M-Theory, so he probably does understand the latest stuff. But my main point still stands. This is just a thing about who gets to build the bigger empire and get more publicity, power and money. Just like the entertainment industry!
Fan of Spaghetti myself. I just want dinner to be possible.
Smolin is highly skeptical of many string theorists' reliance on the Anthropomorphic Principle
That's the ANTHROPIC Principle. Not anthropomorphic.
Tubby or not tubby. Fat is the question
Because theres not a lot else in fundamental theoretical particle physics to spend it on. Basically we've reached the point where everything we can test right now is tested and understood and there hasnt been any significant surprises in the last 30 years. Basically the cludge that is the Standard Model works far too well and its completely theoretically worked out. And the theorists are just screwing around with silly things now because they are waiting for experiment to catch up with theory. We hope that this will happen when the Large Hadron Collider (LHC) turns on and that we will find something unexpected. This will give us the clue what to try next theoretically. And as soon as that happens, the theorists interest in string theory will disappear as they will (hopefully) have something new to work on to explain (hopefully) very strange experimental results. Particle physics is either about to go through a golden age in two years time or its going to wither and die.
On the contrary, string theory is very interesting, and has a great deal of interesting things to say. The issue is more that it is mathematics not physics. There is, of course, nothing wrong with mathematics for its own sake. Indeed, many physics theories were preceeded by the development of purely mathematical work - where would general relativity be without Riemann's work on manifolds for instance? In many ways string theory could be classified in a similar sort of category - it is a lot of very interesting mathematics that could, one day, be applied to the development of a physical theory. The dilemma comes when people act as if it is physics instead of mathematics.
Craft Beer Programming T-shirts
Look how much money the pr0n industry makes.
...wait a minute! THAT string theory ... oops!
Help a man when he is in trouble and he will remember you when he is in trouble again.
As physics progresses we seek for something that was hidden from the previous generation of physics. For example we start with observing gravity happen. 100k years ago (or 6k years ago - depending on your worldview) Ogg drops rock, ogg gets sore toe. Then more recently someone figured out it is because of mass/proximity of objects. Then someone figures out a characterising equation. Then someone else figures it is because space is bent. Then strings. No longer are we improving our observations. Now we're coming out with mathematical models of things that don't really exist.
Engineering is the art of compromise.
As a layman, I'll wait until the mod points are assigned on this article's comments. Then I'll have a reliable introduction to theoretical physics.
If I understand you correctly, there is no way you can raise evidences against or for this theory? :-))
How can it be considered as a scientific theory without any experience at all? (Pardon me my ignorance, I'm a computer guy
Below is the text of an email I sent Dr. Smolin late one night as I was reading the subject book. Ne never answered; if anyone can clarify I would greatly appreciate it...
...
.... -> U has children U1 and U2; U1 has children U1a and U1b; U2 has child U2'; U2' has child U2''...
Sir -
A friend of mine lent me a copy of "The Life of the Cosmos" and I have just reached the point at which you introduce the hypothesis that the observed values of certain of the parameters in the standard model may have arisen in an evolutionary fashion.
It is now four in the morning and I am sending you this letter because I don't think I'll get a good night's sleep until I do. It is possible (albeit unlikely) that I will remain restless until the question the letter poses is resolved, and I would therefore very much appreciate it if you could clarify precisely which universes are members of the "collection" that is of interest.
At first I thought perhaps the answer to this question is "every universe that has ever existed or will ever exist". Upon reflection, however, this choice does not lead to a population in which the number of universes in which black holes can form greatly exceeds the number of universes in which they cannot. Even though the latter have but a single offspring, the rate at which they reproduce (once every few Planck times) is so great that a collection formed according to this definition would surely be dominated by short-lived but "uninteresting" universes.
I have instead nearly convinced myself that you have the following in mind:
Consider the "family tree" of universes. We start with the initial universe, and for an inconceivably large number of generations all we see is a single lineage of parent followed by single child, so:
U -> U -> U -> U -> U ->
At some point, the standard model parameters have randomly changed to the point that at least one black hole can form before the universe collapses. For the sake of argument I will (and I think without loss of generality I may) assume two children:
Since the standard model parameters are so close to their critical values, I show one of U's children (U2) "regressing" to the prior single lineage. But if U1 "inherits" the ability to form black holes, it may have two children (U1a and U1b), and four grandchildren (progeny of U1a and U1b), and eight great-grandchildren, and in general an exponentially growing number of descendants. Some fraction of them may revert to the single lineage state, but in general if we wait long enough and then select a moment in time and put all the universes that exist at that moment in our collection (perforce including U, U1, U1a, and U1b), we have a collection that fits the bill.
However, the manner in which this collection is assembled seems to require some notion of absolute time (or, maybe, "metatime", since the "internal clocks" of all the universes are decoupled), i.e., simultaneity across multiple universes, so that we only include a single instance of those universes that are part of a single lineage chain. I have the impression that physics considers "simultaneous" a meaningless concept when restricted to the framework of a single universe, so is it really kosher to introduce it here?
The SCO lawsuit makes me wish my company were in Utah. We need a new building.
You might want to look at the Transactional Interpretation instead.
Fascism starts when the efficiency of the government becomes more important than the rights of the people.
Yes, physicists need to spend more time and money on other more worthwhile goals. My zero-g flying car isn't going to invent itself. I was promised we'd have flying cars by now.
Well, there's spam egg sausage and spam, that's not got much spam in it.
"Science is prediction, not explanation" - Fred Hoyle
The serious problem with string theory is that it doesn't yield falsifiable predictions. Theories which don't yield falsifiable predictions are not useful - you can't check them by experiment, you can't effectively choose between them, and you can't develop engineering based on them.
This matters. From subatomic physics we got nuclear power. From quantum electrodynamics we got semiconductors and lasers. From string theory we got nothing. If you can't make predictions, you can't do engineering design.
With string theory, you can create pretty mathematical objects, but it's not clear that there's any connection to the real world. Smolin says that's bad physics, and he's probably right.
There's real progress in physics, but it's mostly at the low-energy, low temperature end. Seemingly impossible objects like Bose-Einstein condensates and materials with negative indices of refraction have both been demonstrated. Quantum computing is hard to do, but real. That's progress. But the high energy physicists and the cosmologists have been stuck for a while.
It's possible for an entire field to take a wrong turn like this. Artificial intelligence did, back in the 1980s, when the expert systems people were claiming that strong AI was just around the corner. Then came the "AI winter". Twenty years later, AI is moving again, but with new approaches (more statistics, less formal logic) and new people.
The real stuff is the equations, which all the interpretations agree on. And all the predictions spring from the equations.
The interpretations aren't right or wrong, they are just how we translate the math into our daily language. If the Copenhagen Interpretation works for you, use it, otherwise choose one of the others. It does not matter.
Below I'd like to repost something I once wrote trying to explain why string theorists think string theory is an important approach, to counter the inevitable "it's not science" claims I see on string-related threads.
(I would like to note first that Smolin himself has written string theory papers, and historically has advocated combining string theory with loop quantum gravity, so even he doesn't think string theory is nonsense — he just would like to see it mesh with his own theories and doesn't like the attention it gets relative to them.)
Anyway, my two cents on string theory and its justification and testability:
First, string theory could certainly be tested if we could probe the Planck scale. We will never be able to build an accelerator to do
that directly. There is some chance we might eventually do it indirectly by measuring fluctuations in the cosmic gravitational wave
background. In addition, string theory encompasses many scenarios in which the string scale could be probed at much lower energies, but nobody is very confident that those scenarios are likely to be correct.
That being said, there is a serious possibility that string theory might not be testable in practice, at least in the foreseeable future. I don't believe that puts string theory totally outside the realm of science altogether. String theory does at least make predictions, even if we can't test them. But that is a weak argument. More strongly, string theory is motivated by reason of consistency with known physics. Gravity has to be reconciled with quantum theory somehow. There are strong reasons to believe that string theory overcomes obstacles to quantizing gravity in a unique way that all other approaches can't duplicate, although this can't be proven. That is one of the main reasons why string theory is taken so seriously despite its experimental shortcomings (which are not surpassed by its alternatives, either).
Here are a couple of arguments in favor of string theory put forth by string theorists which I have begun to agree with:
In particle physics, it has been possible to write down theories of the non-gravitational forces while being ignorant of high energy
Planck scale physics. This is essentially due to the Applequist-Carrazone "decoupling" theorem, which uses renormalization
group arguments to show that low-energy physics can be made independent of high energy physics, because at sufficiently low
energies you can't excite the higher-energy modes; therefore, their contribution is irrelevant.
This decoupling breaks down for gravity. Because gravity is a universal interaction, it couples to everything (because everything
has mass-energy); the low energy effects of quantum gravity are never independent of high-energy physics. So you can't write down a theory of quantum gravity unless you purport to know everything about particle physics up to arbitrarily high energies — which of course you can't possibly say, unless you can do experiments at the Planck scale.
This is a criticism that string theorists level against loop quantum gravity. LQG is usually attempted ignoring all realistic particle
physics, and even if that approach succeeded, you'd have to write down a different LQG theory to take into account real particles, which might work completely differently than a vacuum LQG theory. LQGers respond by saying that they want to start by just proving it's possible to quantize *any* kind of gravity using this approach, and then worry about "realistic gravity".
String theory, on the other hand, evades the whole problem. It has a very unique mathematical structure which provides "mysterious" exact cancellations at all orders, rendering low energy physics decoupled from high energy physics despite the universal coupling of gravity.
Thus, it can make predictions about high energy physics even without our being able to make measurements at that scale. No other approach to quantum gravity has shown any signs of being abl
They're simply not science. When we find some way to test them, then they'll become science, physics. Until then, they're just philosophy.
Deleted
One thing I like about this debate is the cool quotes :):
/ 03/14/MNGRMBOURE1.DTL
... Our sciences are becoming increasingly infected with quasi-theology, a tendency which needs to be openly debated."
http://en.wikipedia.org/wiki/Feynman
Feynman, "I don't like that they're not calculating anything. I don't like that they don't check their ideas. I don't like that for anything that disagrees with an experiment, they cook up an explanation - a fix-up to say, 'Well, it still might be true.'"
http://sfgate.com/cgi-bin/article.cgi?f=/c/a/2005
Another Nobel Prize winner, Robert Laughlin considers string theory to be physic's version of postmodernism:
"I think string theory is textbook 'post-modernism' (and) fueled by irresponsible expenditures of money."
"People have been changing string theory in wild ways because it has never worked."
And don't ever mention string theory to Nobel Prize winner Phil Anderson,
"we from outside the (string) field are disturbed by our colleagues' insistence that every new semi-adolescent who has done something in string theory is the greatest genius since Einstein and therefore must occupy yet another tenure track.
The article has some quotes in defence of string theory too but they're not as interesting. The usual blah, blah, blah, give us more time and eventually you'll see that we're right thing.
rimshot
Thank you, I'll be here all week.
There are many tongues to talk, and but few heads to think. -Victor Hugo
I stopped reading after "Anthropomorphic" so I missed that little gem. Oh well any theoretical physicist worth his salt sets c (and every other dimensional fundamental constant) to 1 anyway. :)
Double Special Relativity? Now, that's a better name than "string theory."
Except for ending slavery, the Nazis, communism, & securing American independence, war has never solved anything.
You inject a photon into an atom and it promote an electron.
The electrons are believed to be in discrete orbits, so the photo must be a discrete packet. Bollocks.
Ever since that mistake, we've been in bullshit land where the most fanciful ideas are accepted as fact, just as long as they fit some numbers to some other numbers.
not which theory is better, but how those theories are used. i think your geek god einstein would agree with me. it is actually a damn good thing that we haven't moved on since the 1930s in our basic understandings... it would undoubtedly lead to new and horrific weapons that we are far too immature as a species to deal with in a logical manner. imagine someone purposely engineering something like the black death of europe, or imagine genghis khan with nuclear weapons. imagine if the US had some superweapon that allowed it to do to every unfree country on earth what it has done to iraq. physics can't do anything about hubris, stupidity, arrogance, and ignorance. unless it is the physics of the human brain. you can pretend there is such a thing as 'basic research' all you want, but we all know where the funding comes from, what arguments are used to justify it, which directions physicists are going in, and what the end results will be.
Everyone gets their turn. Now you know how I feel every time a discussion on evolution comes up.
Jeremy
Smolin is right in his critique. But the cause lies deeper. Academic physics (and other branches of science) are controlled. Part of the control involves funding innocuous research such as the mathematical acrobatics of string theory. However, when research gets close to upsetting an applecart, public ridicule, editorial control, and career sabotage is deployed.
For example, we all have been told that cold fusion is bunk, and that quantum theory is so well-tested that it is virtually proven. Well, think again. The cold fusion phenomena are real and have been replicated hundreds of times. And there is a new theory (GUT CQM) that outperforms standard quantum mechanics on the only frontier that really counts: falsifyable and quantitatively precise predictions of observations and phenomena.
that's exactly why it's lived so long. It's interesting because of the math and patterns but completely useless up until now. I think it got started by some misinterpreted findings in an experiment or a shaky conclusion about something in physics that formed some unproveable theories. The implications of certain things in string theory would make some crazy cool inventions, which is another reason why they just refuse to drop it but yeah, I can't think of one single usefull thing that's come out of it. Far from it considering all the grants that have gone into its study. All that money could have been put into a study that goes the other direction, using physics we know and use now to discover and invent more that we didn't know and we'd be flying around in ion jetpacks by now. That would be a nice, steady, straight road to go down while you can see string theory out doing donuts in a dusty field far off of the road and the chances of it meeting up with the road and coming up with something usefull are very slim. Kinda reminds me of finding techniques to calculate pi farther. The goal is stupid but oh yay, they developed new ways to calculate giant floating point calculations and now graphics cards are faster. La dee da, and that wasn't the original intention. They just got lucky with a side effect and it's really not all that important. Of course, the pi calculating computers could have been processing folding and curing cancer and we for sure know that would be the outcome eventually so I suggest all around, we study things we know will pay off instead of just dumb stuff.
Google's Super Secret Search Algorithm: SELECT @search_results FROM internet WHERE @search_results = 'good'
Let's say you're sitting in car, plane, train, whatever. Without having seen the outside of the vehicle, describe to me what exterior color it is, its shape, what it's made of, the interior of the fuel tank, engine, etc. Now isn't describing the universe a bit similar?
What?
You have no idea what string theory is, and you have no idea what Schrödinger's cat is.
"Ugh, stupid!" indeed.
What? But you seem to be complaining mostly about the uncertainty principle?
It seems you think quantum theories are stupid, not the string theory?
Beware: In C++, your friends can see your privates!
You are confusing string theory with quantum theory ...
The one thing that has REALLY bothered me about QM is the whole "Instantaneous Collapse of the Wave function" issue. No matter how may times I read it and read into it, this has never quite made any Intuitive/Physical/Mathematical sense, it seems very much like a contrived device tacked on for the theory to make sense.
String theory is built on top of the edifice of QM without quite solving/fixing any of the basic issues that be-devil it. Is this wise?
Your idea of "real object" is very very strange. Mass?? It's just a characteristic of matter.
Agreed. We cannot tell the difference betwen a "model" and something "real" other than our model of it fitting observations. But fitting observations only tells us how accurate our model is. It says nothing directly about wether something is "real" or not. Wrong models can still fit reality. But perhaps it does not matter. Ideally we would like to have the "correct" model, but a wrong model that produces all the answers the right one does could be equally useful from a technology standpoint (assuming it is not more complicated).
Table-ized A.I.
For those of you interested in the social process of doing science, you may want to check out Kuhn's Structure of Scientific Revolutions. It is a rigorous account of how communities of scientists frequently stick to tribalism (e.g. "the string theory camp" or "the Heliocentric camp" or "the natural selection camp") and how this tribalism structures how science is done. Kuhn's story seems to be reflected in this slashdot story.
(Kuhn didn't use the term tribalism, that's just how I think of it)
The review of the final chapter seems to me to downplay a pretty valid point:
If you have ever refereed a paper, you know that you can't much help approching it like a term paper. You look for places to take points off. Visionary papers are almost always unfinished and so get poor reviews. Perfectionist papers that confirm what everyone thinks any way are harder to ding for points. (And are more likely to be fraudulant.)
Smolin has urged at least one frind of mine to just publish a visionary work to the archives rather than deal with a referee. This does not help with publication metrics that people need to keep their jobs, but it does leave an open channel for stuff that might not be wrong.
Rather than sour grapes, I'd call it honesty.
The 90s called, they want their theory back.
If someone is passing you on the right, you are an asshole for driving in the wrong lane.
The point is that Gell-Mann hasn't written off Smolin, which may lend some degree of credence to him. The only reason Dawkins is mentioned is to properly attribute the quote. I understand your confusion though; proper attribution is so rare on the InterWebs these days.
Build a man a fire, he's warm for one night. Set him on fire, and he's warm for the rest of his life.
I am not a physicist so I can not help much. My only suggestion: Play it like a bridge contract. When playing a contract bridge hand, one always assumes that the cards are placed in such a way so that it is possible to make the contract! If this assumption is false, it does not matter, because there was no chance to make the contract.
Similarly, physicists should assume that the rules of the universe are such that it is possible to escape this solar system before we all are dead. If this premiss is false, we have not lost anything.
Come on, physicists, the UFO space aliens did it!
Indeed, many physics theories were preceeded by the development of purely mathematical work - where would general relativity be without Riemann's work on manifolds for instance?
String theorists would probably argue that it's more like Newton's invention of calculus: math that went hand in hand with the physics that couldn't be described without it. I think it's a little bit of an oversimplification to say that string theory isn't science; it does make some predictions of a very generic kind (e.g., cosomological constant less than or equal to zero, which turned out to be wrong, so they had to patch up the theory to allow a positive value). There are also anomalous observations of extremely high energy cosmic rays that appear to be inconsistent with the standard model, and there's at least some hope that quantum gravity will start interacting fruitfully with that type of experiments, within our lifetimes.
Find free books.
Before you say, "Well, anyone who knows ANYTHING about physics knows that, you retard, this book is not for you..." - well, I did think this was supposed to be a layperson's book. So, I clicked to read this review despite having an effectively non-existent knowledge of physics.
Well, anyway, here's your answer, at least according to Wikipedia (obviously, not being my field, I can't vouch for its accuracy):
Source: http://en.wikipedia.org/wiki/MOND
His black hole reproduction theory is something i have been thinking about for a while. (and here i was thinking i was original)
My idea was:
Black holes constantly grow. As the mass grows the gravitational force eventually reaches a point where it exerts enough force at the center of itself to open a hole in space (wormhole) at the center of the mass.
Since the density on the other side of this hole (probably a big empty bit of nothingness) is so much less than the density inside the black hole, the matter is thrown through the hole with the force of the Big Bang.
This fulfills all the requirements for a "Big Bang" that i am aware of (limited knowledge of theoretical physics). Matter of all types, Large energy release, All matter comes from a tiny point etc
Like i said i have been thinking about this for a while and was considering talking with some of my prof's about it (physics/IT student)
I think you missed the part where you explained what was wrong with his understanding. I can make baseless accusations, too. YOU have no idea what string theory is, and YOU have no idea what Schrödinger's cat is. See. No value added. Just a troll. Incidentally, today someone posted a nice comment about positive trolling that you should read. Please, for the rest of the uninformed masses, why was the grandparent wrong? Why shouldn't we listen to him/her?
from what i understand (no expert on the history, just read a few things here and there), many theories get treated like that. evolution for example was kind of considered a joke for a long, long time. in fact iirc darwin knew it would not only be treated as a joke, but would cause massive social upheaval (social darwinism, which has a straight ideological line to eugenics, and the nazi holocaust).... he only released his theory after a co-discoverer threatened to do it himself...
so rest assured cold fusion etc will find their way into acceptance in a few years, if they are true.
the problem, with cold fusion especially, is that now anybody can make a massive nuclear bomb for a couple hundred bucks of parts from a hardware store.
if the CIA or whoever is suppressing that, honestly, i have to say 'good for them'.
It's only possible to incorrectly measure the speed of light in km/s.
Who ordered that?
1. Strings 2. ? 3. Profit!
...he wants his bong back, man.
I've often tried to wrap my mind around relativity to no avail, and there is one thing that keeps tripping me up. Say clock A moves away from clock B at half the speed of light for some amount of time. From my tiny understanding, it seems people are saying that at the end of A's trip, A and B will read different times? Now, I can understand someone standing next to clock B thinking they see A's hands moving slower than normal as it flies away. The further A gets from B, the longer it takes light to travel from A to B. As A moves away from B, that time lag is slowly increased. After 2 seconds, A will be 299,792,458 meters from B, and now it takes a full second for light to travel from A to B. A has traveled for only 2 seconds, but to B it looks like (visually) the trip has lasted 3 seconds. At this point, visually, from B's perspective, A will always look a second behind. What I don't understand is why that means they both traveled through time at different speeds. If A were to speed back over to B again at half the speed of light, B would see A's hands moving faster, and by the time A got back to B, they would both read the same time again, as far as the person standing at B's side is concerned. Where have I gone wrong?
I have always had trouble understanding the plural of universe. In the English language I believe universe means the absolute all of everything. In physics we see reference to universes. What word is now used to replace the old meaning of universe? When quantum theory and string theory talk of multiple or alternate universes doesn't it really mean alternative realities within the universe? Physics appears to me to break the laws of English language. Didn't Einstein state something about a man who is misrepresenting small matters is usually doing the same in important ones? I think the search for TOE won't be found by being slack with the tools we have established and language is a key tool.
unlike most pop-physics books in ... skepticism of the Copenhagen interpretation of quantum theory
Now, I can't claim to be up to date on the pop-physics scene, but do most people writing for it actually subscribe to the Copenhagen Interpretation? Somewhat surprising, given that CI is basically, well, magic (or the "scientific theory of the immortal soul", whichever way you want to look at it).
Whatever you think of its actual merits as a theory, surely it's still firmly in the outer reaches of "scientifically-minded philosophy", rather than accepted scientific dogma?
That's what really bothers me about the theoretical physcis groupthink: it seems they've completely dispensed with the concept of falsifiability (and, you know, actual physical evidence), and whatever hypothesis presents as the most elegant, or neat sounding (or has the loudest proponents), holds sway. String "theory" is of course the poster child for this phenomenon.
sic transit gloria mundi
If I explained to every person mouthing off on Slashdot why they are wrong, I'd never have time to leave the house. Sometimes, you have to keep it short.
a t
In short: He's confusing string theory and old-fashioned quantum mechanics, while understanding neither. Schrödinger's cat predates string theory several decades, and it is actually meant as a criticism of early quantum theories.
http://en.wikipedia.org/wiki/Schr%C3%B6dinger's_c
http://en.wikipedia.org/wiki/Quantum_mechanics
http://en.wikipedia.org/wiki/String_theory
Hey, I may not know, but my cats sure like string....
the problem is getting it unentangled again after they're done.
Of course, with cats, their position, velocity, and intentions aren't usually simultaneously predictable; even if you get out the electric can-opener, and can therefore predict what their position will be like in the near future, you still don't know which kitchen door they'll come in.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
There may not be much else that's reasonably priced to spend theoretical physics dollars on, so paying professors to write non-experimentally-testable papers may be the way to go, but there seem to still be lots of physicists who want really really expensive test equipment, either really large accelerators/colliders/etc. or else really big orbiting astrophysics equipment.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
It redirects to avoid confusion on the part of the misspellers.
(Unless the Eschaton is trying to prevent any discoveries from creating closed time-like loops or other variants on time travel that might endanger its future existence, ....) your assertion is bogus. Physicists would really like to have some applecarts get upset, especially if it's done in a way that generates cool new theories that require more physics professors to research, test, and teach about them. And cold fusion? Get real....
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Well I'm late to the discussion, so I doubt this will be modded up. But I think it's pretty clear that far from String theory being given a pass, scientifically, it's actually being unfairly criticized.
The first - false - criticism is that String theory makes no testable predictions. It does. The problem is that we simply don't have the technology to test it yet. (And building a particle accellerator to test by brute force may never be humanly possible.)
Unfortunate, yes. But there is a difference between not being able to test a prediction, and a theory that makes no testable predictions. Bose-Einstein Condensates was a testable predition made far in advance of any physical ability, at the time, to execute the test. Did that make the theory any less scientific when Bose (and more abstractly, Einstein) proposed it?
The second criticism is that String theory is just math. Let me remind you that String (M-) theory is still one of the very few self-consistent models that entirely subsumes all other physical theories. When created, it was the only model that wasn't flat out disproven by the evidence.
Again, unifying math may seem like a trivial point to some people. But it's not. Scientifically speaking, any theory that predicts things and isn't proven wrong (yet) beats a theory that is proven wrong, no matter how useful it was in the past.
actually I know exactly what they are. String theory explains everything, and everything includes quantum physics. The fact that an atom may or may not emit radiation determines by how a string vibrates and maybe even if it does at all or not but anyway, then like some particle that goes along with another particle make up the radiation that comes off and one's radiation and the other is a physical particle and they both vibrate differently but are both strings and blah blah blah. And the cat thing is where a radioactive substance has an equal chance of radiating or not and it's completely super-exact random and if a radiation detector receives radiation, it radiated and the sensor trips a thing that kills the cat but if nobody and nothing is "observing" (a term nobody can explain fully yet) the result then neither and both of the results happened. Why this is stupid is because you'd have to "observe" it to find out if that's true but then one of the outcomes would come into being in this universe. But then again, I could say little magic multi-dimensional unicorns carry the cat off to la la land where it turnes into a black hole and travels faster than the speed of light to every point in the universe at once (like war 10 lol) until something observes the event and nobody could disprove it and there is NO WAY TO TEST IT. So that's why it's incredibly stupid. Yes it's not directly linked to string theory but string theory explains all particles and all energy so yeah, it's related to string theory because quantum physics has to do with how particles and energy (aka string then) act.
Google's Super Secret Search Algorithm: SELECT @search_results FROM internet WHERE @search_results = 'good'
That's why the newly formed Israel, a JEWISH nation, as in not atheist, as in believing in God, asked him to be the prime minister.
a few months ago? Thought so.
I mean, really, isn't saying it's a loop almost just like saying it's a string?
299,792,458 m/s would be a much more appropriate number, though 3x10^8 m/s is good enough for tests :)
If you can't even remember one of the key concepts in a book you're reviewing...
But all I have to say to either side is Prove It! Until then, I really couldn't care less who thinks what theory is correct.
"Organizations which design systems are constrained to produce designs which are copies of the communication structures of these organizations. "
-- Conway's Law
Ergo hoc, thusly and heneceforth,
Let our mind be Conway's system which designs other systems. These other systems are those which we use to interpret the nature of the universe. Since we cannot design a system more complex than our minds, we are destined to at most create a model of our minds rather than a model of what contains our minds; the universe.
This is why mathematics is so inexplicably good at describing the universe; it simply isn't doing that. Instead, what it is doing is describing the minds which have created it. Enter string theory.
All rites reversed 2010
Are you sure it wasn't Feynman that said that?
Or maybe even this guy http://www.aip.org/pt/vol-57/iss-5/p10.html
the fundamental principle of the given A,B,C example is based upon newton's laws, for helicopter gunships firing missiles the principle this: the velocity of the launched missile is added to the velocity of the helicopter (air resistance, opposing force of launched rocket and momentum asided, let's keep it simple!) to get the "final" velocity of a rocket. i.e. if you've got a launcher that launches projectiles at 10m/s and you are travelling at 100m/s fire it forward and the projectile goes 110m/s.
the problem i have is when this is applied to light, which is massless and intangible. The example assumes that a laser fired from the front of a space freighter (travelling at velocity V) would - according to newton - have a resulting velocity of c + v. relativaty tries to bend time itself so that c = c+v can be true without v==0 being true. However, light isnt actually launched - it's emitted, maybe, just maybe, because it has no mass too it is not effected by the velocity of the space freighter, maybe it just goes along on it's merry way at c regardless. The people on the space freighter might start to see some wierd-assed things as their speed approaches c and they start to catch up with their own emmitted light (and relativity expects this: it yeilds a blue shift forward and a red shift aft). But frankly i find the idea that because light is travelling at a fixed speed and everything looks a bit wierd you make a giant leap to frames of reference and warping spacetime bizzarre.
Naturally of course relativity is real and observable, but it could be that Einy stumbled across it by accident whilst trying to bend his mind around an entirely different - and non existent - problem.
Alternatively, i just might not *get* it, i do have a physics degree, but my final grade wasn't exactly up there (i spent far too much time in the computer lab playing with the new interweb thingy).
If you don't risk failure you don't risk success.
May the Maths Be with you!
Aside from the aforementioned reference to the mysterious "MOND," there's this bit that sticks out to me
"One such thing is that Smolin seems to have a soft spot for Paul Feyerabend as a philosopher of science (despite describing himself as a proud Popperazzo in an endnote)."
Are we supposed to know the name "Feyerabend" and the term "Popperazzo" off the top of our heads? At least the much-derided "pop physics" works actually try to explain themselves rather than taking the Slashdot "RTFM n00b!" attitude.
I am no physicist, but I do follow physics to some degree (kind of like it was my favorite sports team: I can't do it, but I enjoy knowing what's going on). My understanding has been that String Theory (A 10 dimensional theory) can explain anything we observe in our universe if we invent a very specific theoretical parallel universe to satisfy the equation. This is troubling to me because it gives you free reign to invent new physics whenever they can't find the answers they are looking for. M-Theory (An 11 dimensional theory) is basically complimented by string theory because in includes an 11th dimension (A membrane which exists within an extremely close proximity to everything within our universe) and, as I understand it, contains limitless parallel universes and strictly speaking, our universe is there too. Therefore, String Theory is an expression of M-Theory and "alternative loop quantum gravity" (I think also referred to as the "Super Gravity" - originating in the 11th dimension) is also complimentary to M-theory. My question - what's the problem? It sounds like an old argument all over again. I thought they had each accepted their place in physics and peace had been accomplished.
I think before you try to learn about string theory, maybe you should learn about sentences and paragraphs.
You mean, the theory can be tweaked to explain about anything one might observe? Or is there any possible observation where one would say, if that observation is made, string theory is dead, period? Because that latter property is what is usually called falsifiable.
The Tao of math: The numbers you can count are not the real numbers.
I just finished this book recently. Another major objection Smolin has to String theory is that it is "background dependent" like quantum theory: that is, it depends on the perspective of the observer, which flies in the face of Einstein's revolution. He finds deeply unsettling the possibility that there is a preferred position or direction of motion in the universe. He laments the lack of physicists interested in the fundamentals of the science, saying the academy is set up to favor technical prowess in mathematics rather than any philosophically new ideas in physics, which are desparately needed in his view. He mentions several other prominent scientists who share this concern for needing revolutionary ideas (Roger Penrose, for instance). I'm disappointed in this review: it didn't do the book justice. As a lay reader, I found it easier to follow than Lisa Randall's book Warped Passeges (or Penrose's difficult Road to Reality), and less "cheerleadery" than Brian Greene's books, but nevertheless very exciting.
It's esily verificable because some possible experiments has been already proposed:
http://en.wikipedia.org/wiki/Heim_theory
This theory also succesfuly predicts masses of all known and some unknown particles. The predicted masses have been derived by Heim using only 4 parameters - h (Planck's Constant), G (Gravitational constant), vacuum permittivity and permeability. For example theory predicted that neutrino got mass in 1980s - long before it has been found by experiment.
Also another prediction of gravitomagnetic force (Heim-Lorentz Force) proposed here:A IAA2005-4321-a4.pdf
http://www.hpcc-space.com/publications/documents/
seems to be validated by ESA (European Space Agency) experiments:l A rtificialGravity.pdf
http://www.esa.int/SPECIALS/GSP/SEM0L6OVGJE_0.htm
http://www.hpcc-space.com/publications/documents/
http://arxiv.org/pdf/gr-qc/0603033
This theory also explains the "Dark Matter" phenomenon.
If Heim theory is true then it will mean that we will most likely be able to travel with superluminar speed and produce artificial gravitational fields (antigravitation):A IAA2006-4608LetterExtndVersionRevised.pdf
http://www.hpcc-space.com/publications/documents/
It's much easier to test then string theory, so why do not to direct some extra attention and money for further testing it??
All Einstein meant was that god doesn't play dice because non-existent entities don't play (or say or do) anything. :) He could just as easily have phrased it "That god won't hunt."
- First they ignore you, then they laugh at you, then ???, then profit.
What the hell are the strings made of?
(Emphasis mine)
Source: http://www.ap.org/pages/about/whatsnew/wn_112905.
Build a man a fire, he's warm for one night. Set him on fire, and he's warm for the rest of his life.
Yes, I know that was a comment on a throwaway. : )
The main issue that is confused in the "string theory is unfalsifiable" debate is that people compare string theory to some specific QFT model like the Standard Model, where it should instead be considered as a generic framework in which to write down specific models, like QFT itself. You can construct easily falsifiable models within string theory, just like you can in QFT. But falsifying all of string theory is about as hard as falsifying the QFT framework itself.
They hate that....
Human genome = 3 billion base pairs = 6 GBit. Windows + Office = 20 Gbit. Which is more impressive?
I was slightly disappointed with the final chapters of Smolin's book since, despite an obvious effort to the contrary, it struck me as awfully bitter and reeked of sour grapes.
Have you noticed that is really hard to raise a complaint, however valid, without having it sound like sour grapes? Tellingly the parent post criticizes the tone of Smolin's delivery without addressing the substance. Is physics in a dead end trajectory, which in particular is now reflected by the lack of increase in funding? is the system self perpetuating in its erroneous ways? Those are very valid questions and physicists would be well advised to ponder them very carefully. The future of their discipline depends on them.
If Smolin is right, physicists in large departments are in a state of group-think refusing to see faults in the current directions of research. I don't know if he is right or wrong, but he is certainly right to _ask_ the question, after thirty years of non-results from string theory, and declining funding.
You could have educated yourself in the time you instead expended in boasting of your own ignorance.
"I used to be a big fan of MOND (in a layperson sense) until Smolin introduced me to DSR (doubly special relativity) and DSR II."
I don't understand this assertion. These are two very different theories. They don't even solve the same problems. MOND works on Galaxies and their rotation curves. While DSR attempts to fix the boundary of Relativity and Quantum Theory. MOND is silent on Quantum Theory. And DSR is silent on Galaxy Rotation curves. I don't understand why they should be mutually exclusive. Unless you thought that somehow DSR will predict the Galaxy rotation curves, which isn't even probable.
MOND is adhoc but the a0 factor gives rise to speculation that it arises out of the curvature of the universe, as it is related to the Hubble's Constant, while Planck's Constant is a fundamental constant. I am a big fan of MOND, and like most MOND believers expect that some deeper theory will be found out eventually that will produce the MOND phenomenology. I do expect that eventually Gravity will be found to be conformal in nature like the other three forces.