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String Theory a Disaster for Physics?
BlueCup writes "Mathematician Peter Woit of Columbia University describes string theory in his book Not Even Wrong,. He calls the theory 'a disaster for physics.' Which would have been a fringe opinion a few years ago, but now, after years of string theory books reaching the best sellers list, he has company."
No. The parameters of string theory can be bent far enough to encompass almost any observation predictable by other current theories. String theory can't predict anything reliably as a result, and can't be tested. That's why it's a disaster for modern physics. RTFA or STFU.
ResidntGeek
Let me point out that this has been well known in physics departments for years. The problem is string theory is nowhere near producing any prediction that can be tested, this means that it is not science, any more than mathematics is physics.
Did Glenn Beck rape and kill a girl in 1990? gb1990.com
Michio Kaku in his book Hyperspace describes why we can't actually get very far with this theory, is because "nobody is smart enough to figure it out". Since it was an accidental discovery in the 80's, he describes it as "21st century math that accidently made its way into the 20th century". The problem is to do with phase shifts and perturbation theory:
(Excerpted from Hyperspace: A scientific Odyssey through the 10th dimension)
To understand this form of tunneling, think of an imaginary Charlie Chaplin film, in which Chaplin is trying to stretch a bed sheet around an oversize bed. The shit is the kind with elastic bands on the corners. But it is too small, so he has to strain to wrap the elastic bands around each corner of the matress, one at a time. He grins with satisfaction once he has stretched the bed sheet smoothly around all four corners of the bed. But the strain is too great; one elastic band pops off another corner. Every time he yanks an elastic band around one corner, another elastic pops off another corner.
This process is called symmetry breaking. The smoothly strechted bed sheet possess a high degree of symmetry. You can rotate the bed 180 degrees along any axis, and the bed sheet remains the same. This highly symmetrical state is called the false vacuum. Although the false vacuum appears quite symmetrical, it is not stable. The sheet does not want to be in this stretched condition. There is too much tension. The energy is too high. Thus one elastic pops off, and the bed sheet curls up. The symmetry is broken, and the bed sheet has gone to a lower-energy state with less symmetry. By rotating the curled up bed sheet 180 degrees around an axis, we no longer return to the same sheet.
Now replace the bed sheet with ten-dimensional space-time, the space-time of ultimate esymmetry. At the beginning of time, the universe was perfectly symmetrical. If anyone was around at that time, he could freely pass through any of the ten dimensions without a problem. At that time, gravity and the weak, the strong and the electromagnetic forces were all unified by the superstring. All matter and forces were part of the same string multiplet. However, this symmetry couldn't last. The ten-dimensional universe, although perfectly symmetrical, was unstable, just like the bed sheet, and in a false vacuum. Thus tunneling to a lower-energy state was inevitable. When tunneling finally occurred, a phase transition took place, and symmetry was lost.
Because the universe begain to split up into a four- and a six-dimensional universe, the universe was no longer symmetrical. Six dimensions have curled up, in the same way that the bed sheet curls up when one elastic pops off first. For the ten-dimensional universe, however, there are apparently millions of ways in which to curl up. To calculate which state the ten-dimensional universe prefers, we need to solve the field theory of strings using the theory of phase transitions, the most difficult problem in quantum theory.
I'll subscribe to Slashdot when I see a month without a dupe, a typo, or an article the "editors" didn't read.
Jesus that's a bad typo. But I guess I can claim that for every dupe an editor makes I get a typo... so I'm still in the green.
I'll subscribe to Slashdot when I see a month without a dupe, a typo, or an article the "editors" didn't read.
I am an (ex-) particle theorist. I worked on phenomenology, which is how particle physicists describe people try to work with actual data.
I don't think the rise of string theory has been the cause of the dearth of breakthroughs in particle physics in the last 30 years, but rather the effect. For all that time, nothing unexpected has come out of accelerator experiments -- just more confirmations of the predictions of the standard model developed in the 1970s, and more accurate measurements of its parameters. In an environment like that, it's no surprise that theoreticans turn to highly speculative and mathematically challenging models to keep their work interesting.
There are still some related fields generating new and interesting data for good young theorists to cut their teeth on -- cosmology, for example.
I think ST is a very interesting and peculiar theory. I'm not sure it's a disaster. Even if ST is proved wrong in some way the math that resulted from ST is still worthwhile.
Think of Newtonian physics. We now know that Newton falls apart when viewed under the lens of Einsteinian relativity. But if you're dealing with relatively small masses, at relatively slow speeds, then Newton's physics works perfectly because relativity is too small a factor to affect the numbers. Likewise with quantum mechanics at the macroscopic level.
Neither of those three "theories" is a complete and accurate view of how the universe works. They are each of them a model for certain situations, and which one you choose depends on which one is most appropriate.
The thing about string "theory" is that it's more of a model than a theory. When physics gets down to this level, it's more mathematics than science. The theory/model that you use is never going to be perfect or complete, but as long as it fits the purposes you want it for, it's good.
unprovable
You have no idea what you're talking about, do you? What makes something science is whether or not it is disprovable - or to put it another way, testable.
How we know is more important than what we know.
IAAP (I am a physicist). Out of all the bloviating, often obnoxious high energy physicists who feel compelled to write popular books with pretentious titles (Dreams of a Final Theory (Weinberg); The Quark and the Jaguar (Gell-Man); The God Particle (Lederman); The Cosmic Landscape (Suskind); A Brief History of Time (Hawking)), Kaku has absolutely contributed the least to the actual science. Lisa Randall is 10x the physicist of Kaku, if not moreso.
I am a string theorist. I would write my own rebuttal to Peter Woit, who is well known in the community for being very vocal about his opinions, but it has already been well done (these are blog posts by Sean Carroll at Chicago/Caltech).
I'm all for public education on all topics of physics, including string theory, but this is an unfortunate case of a little bit of knowledge being dangerous for armchair physicists. In order to properly understand string theory requires understanding conformal field theory, supersymmetry and supergravity, Riemann surfaces, Kaluza-Klein theory, and so on, just to name a few of the introductory ideas. I don't think it's too unreasonable to assume that most of Peter Woit's audience has not studied any of these. But without studying string theory, I don't think it's possible to judge whether or not the things string theorists find compelling are in fact sufficiently exciting to warrant the attention it receives from them. For my part, I think they are.
There are dualities between string theory and quantum field theory that allow intractable QFT calculations to be performed using string theory methods. In some cases, millions of Feynman diagrams can be summed up by translating the problem into a string theory problem. While some people view string theory as being largely made up, theoretical physics is all about constraints. In order for things to be physically consistent a large number of aspects must fall into place. Even if string theory doesn't eventually fit the bill, the investigation thereof allows us to sample the space of theories, so to speak, so get an idea of what the ultimate theory will look like.
I know it is a joke, but I just felt like responding to it because lots of people seem to have trouble grasping the concept inifinity.
Just because there is an infinite number of universes, doesn't mean that every possible variant of the universe exists. There is for example an infinite number of even numbers. 5 is however not among those.
Another interesting property of infinity is that there exists as many even numbers as there does whole number. This is easily verified by the formula f(x) = 2*x. For every whole number you can find a matching even number. Therefore there is the same amount of both.
So the next time you hear infinity + 1, rest assured that the result is the exact same infinity.
Cold gaze *shudder* http://physics.harvard.edu/people/facpages/randall .html
http://www.edge.org/3rd_culture/trivers04/images/r andall300.jpg
Let's reword the post, then:
"If we were to accept the existence of God as a scientifically valid explanatory principle, it would also be a disaster for modern science. It's not science. It allows for every answer and is not testable."
This follows because the proposition "God did it" admits no proof outside of circular, tautological reasoning in which one can use apologetics to justify the proposition aside from, or in spite of, any evidence. It can't be falsified, and if the non-falsifiable is admitted as a scientific explanation, then science has fundamentally erred.
Or, to put it another way: the epistemological justification grounding any scientific explanation is its falsifiability. Without that, it's nothing but hot air. It holds no more epistemic validity than the statement, "cheese fries are better than hot dogs."
You're right about one thing: science can flourish in a civilization that holds dear many non-scientific beliefs. These beliefs can inspire scientists. They can guide our choices about what to study. But when those beliefs get confused with science, we're in trouble.
The plural of 'anecdote' is not 'data'. --Dan Kaminsky
May be in 20 years from now we will read a very similar article about the impact of "most" of the systems biology work on Biology compared to the current view on String Theory on Physics. Systems Biology can easily generate untestable hypotheses and keep thousands of scientists busy forever.
Looks like his book doesn't come out until September 30. You can, however, check out his blog with the same title, Not Even Wrong.
I'm confused here. The sun is (pretty much) unmoving, and emits a (pretty much) spherically symmetrical gravitational field. So wherever the Earth is, the 'gravitational attraction vector' is going to be pointing to the sun - as that's the direction of the gravitational field. As the mass of the sun is (pretty much) unchanging, there will be no changes to the gravitational field over time, and things continue just as in newtonian physics.
Complications to this probably arise when you've got more bodies in the system, though - so if you include the other major planets, you'll get effects such as you're talking about, but they're on a far smaller scale than you think as the sun's so big in comparison.
(Note that the same does not apply to pulsars, black holes and the like - where there's a lot more mass, and things are a lot more extreme.)
It also happens to be philosophy -- possibly mathematics -- rather than science.
The only way (that I know about) to prove "all X have Y" in science is to enumerate all X, which typically isn't possible in the physical world, and even if you do that, you still haven't proved that "all X must necessarily have Y".
... buddy.
http://outcampaign.org/
Then I started wondering if "brane" might actually mean something. In case I am not the only one who didn't get it at once:
http://en.wikipedia.org/wiki/Brane
Verification is absolutely important, but much more important is that the theory have the property of falsifiability: That you can setup experiments that would falsify the theory.
The school of Karl Popper asserts that science progress by trying to falsify it's own theories. Much has been argued against this, in particular that there are so many ways to keep on doing that that this is not very progressive, so people argue that scientists should try verify their theory with observation.
Yet, I think, this should not discard the criteria of falsifiability as a fundamental criteria of science, and scientists must be prepared to be proven wrong. This is what distinguish science from all the pseudo-science and crackpot.
Secondly, theories should be kept as simple as possible - I think this originates from Albert Einstein, but I have forgotten the original quote - if you can describe something in a simple manner then it is likely to be that way, while a complex theory may obscure the simplicity while describing correctly the world as we see it.
If ST fails on these then ST should be discarded as crackpot.
Uhm... correct me if I'm wrong, but I seem to remember the Japanese getting data that showed pretty clearly that neutrinoes have mass about 5-6 years ago. That's a VERY long time. In addition pretty much EVERYONE *believed* that the experimentalists would eventually find neutrino mass. I remember that being the prevailing opinion approx 10 years ago. That hardly makes discovery of neutrino mass a recent surprise.
I'd say yes. Plus she's a geek chick. What more could you ask for?
But why is the rum gone?
"Secondly, theories should be kept as simple as possible - I think this originates from Albert Einstein, but I have forgotten the original quote"
Most famously attributed to William of Ockham:
http://en.wikipedia.org/wiki/Occam's_Razor
The revolution will not be televised... but it will have a page on Wikipedia
Well, gravity is instantanious in the sense that the sun will instantly pull on a new body of mass if we were to create one here. The gravitational field is established and changes at the speed of light, but the gravity itself is instant. So if the Sun disappeared right now, the earth would continue to orbit it for around 8 minutes.
Jeremy
then the statement "all cats have tails" is simply an arbitrary definition of "cat", rather than a useful scientific theory.
Exactly. Just like Newton's second law - there is no alternate definition of force, so Newton's second law is actually just a definition.
Newton's third law is a theory, though (and depending on the wording, an incorrect one).