Current Thoughts in String Theory 391
DrLudicrous writes "The NYTimes is running a nice little synopsis of the current ideas in string theory. Apparently, there is still quite a bit of disagreement about how to interpret the various theories, with some string theorists supporting a semi-deterministic worldview a la Einstein (God does not play dice), while others believe our universe is just one possibility among many, with respect to various physical parameters."
Fringe science, or valid? (Score:5, Interesting)
Still, intriguing stuff.
Re:Fringe science, or valid? (Score:2)
Calling superstring "theory" fringe science is entire appropriate. An untestable hypothesis is just that; a hypothesis. It won't become a theory until it can be experimentally tested.
Re:Fringe science, or valid? (Score:3, Funny)
Re:Fringe science, or valid? (Score:3, Informative)
Re:Fringe science, or valid? (Score:5, Interesting)
Science isn't so much about finding the "material truth", it's about finding an appropriate "model". For instance, Newton wasn't wrong per se, his model was just incomplete. We still use his model for predicting the majority of practical behaviours outside of experimental physics. Einstein came up with a better model, but we know it isn't complete because relativity and quantum mechanics are not compatable. Still, those models work in their respective applications.
If superstring theory is able to work at predicting all behaviour we can observe, it doesn't really matter if the concept is correct. In other words, if two different phenomena (conceptually) always produce the exact same results, does it matter if our model is based on the "real" one or the ficticious one?
True, there is a desire to know the "truth" of a given situation, but a model that works for all observable phenomena is certainly sufficient for most reasons we use science. Requiring that we create a phenomenon that we can't normally observe is useful for testing the truth of the model, but not necessary its practicality.
Re:Fringe science, or valid? (Score:3, Insightful)
A theory is a systematization of ideas.
An hypothesis is a claim about the relation
between a theory and reality.
Reality is really real.
Fringe means "not popular with the in-crowd yet".
"Untestable" means you haven't figured out the
right experiment yet.
Re:Fringe science, or valid? (Score:3, Funny)
Yes but no (Score:5, Informative)
BUT, there could very well be places that do have this necessary energy and could be observed to exhibit traits that we can measure and confirm theories with. This has been how most of the more recent unification theories have been confirmed -- either by measuring very small things with very fine equipment or measuring very large things in space.
Re:Yes but no (Score:4, Insightful)
Re:Fringe science, or valid? (Score:5, Funny)
Well that would require some sort of a Rebigulator which is a concept so ridiculous it makes me want to laugh out loud and chortle.
Quantum Computing (Score:3, Interesting)
Re:Quantum Computing (Score:3, Insightful)
Re:Quantum Computing (Score:3, Informative)
Re:Fringe science, or valid? (Score:3, Interesting)
String theory, IMHO, is a return to the mindset of physicists and scientists who relied on the 'Aether' as a medium for energy and movement through the vacumn of empty space. I personally think it will u
Re:Fringe science, or valid? (Score:5, Informative)
Bollocks. Einstein's relativity could be readily tested at the time by measuring the bending of the light by Sun's gravity. That's exactly what made them so strong and actually respected by the experimentalists.
To an experimentalist a theory is just hot air until it can be tested in practise.
Re:Fringe science, or valid? (Score:5, Informative)
The conclusion at the time was that General Relativity was confirmed, because the likelihood of measurement or equipment error seemed to have been greater with the result consistent with Newtonian gravity.
Re:Fringe science, or valid? (Score:5, Informative)
Einstein's General Theory of Relativity provided an explanation for the motion of the perihelion of Mercury's orbit. Further, it correctly predicted the magnitude of this motion [bartleby.com]--all of about 43 seconds of arc per century. It's a small motion, but it had been observed, measured, and puzzled at by astronomers in the nineteenth century.
Aside: Many people cite the 1919 eclipse observations made by the Royal Astronomical Society (also mentioned in the link above) as a further early proof of relativity. Though this is the most popular early 'proof', it is tainted with uncertainties. More recent work suggests that the precision of the RAS' instruments was insufficient for the task--the good agreement with theory was likely largely coincidence. Indeed, contradictory results from later eclipses and other groups did follow in succeeding decades. (Measurements with modern instruments have, of course, borne out relativity.)
Re:Fringe science, or valid? (Score:3, Informative)
Re:Fringe science, or valid? (Score:5, Funny)
This is why I prefer sillystring theory. You can easily prove or disprove the effects of sillystring in a great many environments. For example:
1) If I shoot sillystring at the hot blonde across the room, will she sleep with me, or slap me?
2) How slow must I drive on the freeway to enable me to shoot sillystring, and still have it maintain cohesion enough to obscure another driver's windshield completely?
3) If I replace my roommate's shaving cream with sillystring, how many times will he cut his face before he realizes the switch?
You see? Definite, provable, questions. None of thos "alternate universe" or "quintuple bajillion watts of energy" problems.
Re:Fringe science, or valid? (Score:3, Interesting)
Fringe Science" - that's a loaded term ... sort of makes you think of lamarcism, piltdown man, etc.
Re:Fringe science, or valid? (Score:3, Interesting)
The same can be said of any Grand Theory of Everything, however. If you're going to probe the limits of the universe, it doesn't matter what theory you cling to - Planck is Planck is Planck.
On the other hand, any sufficiently strong Theory of Everything will not only explain
Free Link (Score:5, Informative)
Mirror (Score:5, Informative)
Martin Studio Slashdot Policy [martin-studio.com]
Good Info on String theory (Score:5, Informative)
Re:Good Info on String theory (Score:4, Interesting)
There is also a very interesting book called Elegant Universe. I really haven't seen anything that compared to it.
Re:Good Info on String theory (Score:3, Informative)
It starts with a very easy to read introduction to Relativity (special and general) and Quamtum Mechanics. Then it starts to twist your mind with all strings, oscillations, extra dimensions, etc. Very interesting stuff.
What I find amusing about it is when my non-geek friends ask me what I'm reading and I try to explain to them what it talks about... oh the look on their faces when we talk about the Un
String Theory (Score:4, Funny)
Re:String Theory (Score:5, Funny)
God ? (Score:3, Funny)
yep god is much more sophisticated, it's all decided through russian roulette.
Re:God ? (Score:3, Funny)
God goes for video poker (Score:2)
Re:God ? (Score:2, Funny)
Re:God ? (Score:5, Insightful)
on pseudorandom oscillation (Score:5, Funny)
Cats are fickle.
Theory vs Reality (Score:4, Interesting)
Re:Theory vs Reality (Score:2, Interesting)
Re:Theory vs Reality (Score:3, Informative)
So, to play a little mind game with her, I asked her how she knew the earth was a sphere.
If she was a little more up on her knowledge of the ancient history of science, she would have described the famous experiment of Eratosthenes [rice.edu] where he simply used two sticks and a measuring stick to not only figure out that the planet was round, but also come up with an accurate estimate of it's circumfrence.
GMD
Re:Theory vs Reality (Score:2)
Re:Theory vs Reality (Score:2, Informative)
Also, a theory created now that predicts observations which can only be made in the future can still tell us which observations we have to make to validate or invalidate it and like theories.
Re:Theory vs Reality (Score:2)
Re:Theory vs Reality (Score:2, Insightful)
Re:Theory vs Reality (Score:2)
Theories must be tested for science to progress. How do you propose that we obtain theories to test while skipping the part of the theory creation process where there isn't yet enough data to know whether they are true?
Re:Theory vs Reality (Score:2)
Re:Theory vs Reality (Score:5, Insightful)
The observation is that there are two fields of physics that have been rigorously tested and widely accepted, but are only really valid in their own domains. The problem that faces modern physics is how to reconcile this disagreement. The difference between string theory and turtle theory is that string theory is reduces down to quantum theory and relativity when suitable constraints are placed on it. Stop me if I'm wrong, but I don't think turtle theory can do that. The fact that current technology is unable to verify the theory through experiment is a temporary situation (and a unique one. Through most of history, experimental observations have triggered theoretical research.)
String theory might be pushing the limits of science, and it might be completely wrong, but it has a strong foundation, and it attempts to address a big question, and that should be reason enough for scientists to keep working on it.
Re:Theory vs Reality (Score:3, Funny)
Through dark turtle energy, of course.
But... (Score:5, Funny)
wait.. (Score:3, Insightful)
how can it disappear? does dark energy not follow the laws of conservation? (energy can neither be created, nor destroyed, only changed) any one have an answer?
Re:wait.. (Score:2, Informative)
Re:wait.. (Score:2)
The energy will eventually go into expanding the compacted dimensions, leaving us with a fully 10-dimensional universe.
Einstein quote (Score:5, Insightful)
I think that quote (or rather, truncuated paraphrases thereof) is much abused. What Einstein is saying (which is much clearer in a fuller context) is that while the probabalistic equations that comprise much of quantum theory are valuable as descriptive and predictive tools, they do much less to further Einstein's cherished ideals of really understanding the fundamental basis of physical reality. The statement "I am convinced that He does not throw dice" is a statement that while the equations of quantum mechanics might behave like statistics, they did not mean that the underlying reasons for why these equations work were simply artifacts of random, statistical processes - mere throwing of dice. Our ongoing failure to connect all the dots of the various paradigms could indicate that he was on to something...
Re:Einstein quote (Score:4, Interesting)
I will admit to not understaning much of the term of QM I had to take in my physics major
Re:Einstein quote (Score:4, Interesting)
Leading us to another great misquote, "those who are not shocked when they first come across
quantum mechanics cannot possibly have understood it," Niels Bohr, which gets turned into something like, anyone who thinks they understand quantum mechanics doesn't, which is really a totally different statement. It's not that you can't "understand" it - it's that the implications of the theory are simply shocking.
Both your statements about Einstein are perfectly true though. The Brownian motion work tends to be overshadowed by the relativity, but its actually elegant and significant science that was later backed up with some baroque and inventive experiments. And no, he could never accept the quantum mechanics entirely - not its reliance on probabilities and not the world where things could have no precise position and momentum. But as you note, he was never able to build a case against it that had any traction.
I don't know if anyone but the true math-heads really understands quantum mechanics. I took a fair amount with physical chemistry, and while I could grasp what was presented to me by the teacher, it was pretty damn clear that I wouldn't ever be coming up with stuff like that on my own. I remember very clearly being taught the proof for Heisenberg's uncertainty principle. It was so elegant and undeniable - either this is the way it is or else our most fundamental definitions of matter and energy have to be scrapped. But I never would have figured it out on my own, and I can't really remember it now - it would be hours of unpleasant work with the calc book and scratch paper to take myself through the proof on my own. Ah well. Quantum nostalgia (o particle in a box, we hardly knew you!)
My Thoughts on String Theory (Score:4, Funny)
I do have a theory on string cheese, though. I think it's a plot to tempt and destroy the lactose intolerant. So cheesy...so convenient...so stringy but oh so dangerous.
If particle man got in a fight with string man who would win? If he's underwater does he get wet or does the water get him instead? (They Might Be Giants)
Re:My Thoughts on String Theory (Score:2)
A challenge? (Score:5, Funny)
And like most of them, he doesn't document.
Re:A challenge? (Score:5, Funny)
> And like most of them, he doesn't document.
Worse yet, he writes in Perl! *ewwww!*
The Devil, however, codes in TurboPascal.
Re:A challenge? (Score:2)
Re:A challenge? (Score:2)
Nah, Jesus uses ASP. Buddha uses Python.
Re:A challenge? (Score:4, Funny)
Yes, but wouldn't reverse engineering God's code violate the DRM?
Re:A challenge? (Score:2)
Divine Rights Management?
Or maybe it would violate the DMCA (Divine Message Copyright Act)???
Deeper questions... (Score:4, Funny)
One Cosmic Answer, Too Many Questions (Score:2)
The answer is painfully obvious to those of us who have taken the red pill...or seen the Matrix.
Unfortunately no one can be told what the matrix is, you have to see it for yourself. It is the world that has been pulled over your eyes to blind you from the truth.
The world is the way it is, because you are made to think that it is the way it is.
Elegant Universe (Score:3, Informative)
Yes! and other good physics books (Score:3, Informative)
Some other good physics books that don't focus on String Theory that I also thought were very readable:
For Dark Matter and Dark Energy- Quintessence [amazon.com] by Lawrence Krauss (who also wrote the Physics of Star Trek)
For Quantum Computing- Minds, Machines and the Multiverse [amazon.com] by Julian Brown
God playing dice. (Score:2, Insightful)
An all-knowing and all-powerful God would have no problem predicting the outcome of dice. They are physical objects governed by all the physical relationships that govern things like gravity, collisions and such.
The magnitude of the complexity of the outcome of dice seems to be too complicated for any human or machine to calculate a result.
Random outcome of dice is just a concept to help us deal with extremely complicated situatio
uncertainty (Score:3, Informative)
And the point of QM is that such "relationships" fail miserably when subjected to small distances, energies, single particles, etc.
Random outcome of dice is just a concept to help us deal with extremely complicated situations.
Not necessarily. I'll assume you're not really familiar with all the
Re:God playing dice. (Score:2)
In any case...
(Theological babble to follow)...
I believe that in a way God did roll the dice. God gave man free will. By doing this, he has essentially rolled the dice since he does not control what man does. If he did not give man free will, then he did not roll the dice (because he still controls everything, even ones' actions
Re:God playing dice. (Score:2, Funny)
Yes. A woman's thought process.
"Sorry, Adam. I didn't see that one coming either."
a great primer.... (Score:2)
http://www.amazon.com/exec/obidos/tg/detail/-/0
great book and i'm not even 15% done yet. we are all traveling at light speed through the spacetime continuum.....
Re:a great primer.... (Score:2)
Fudge Factor (Score:4, Funny)
If Einstein's fudge factor is real after all, the universe will continue to expand faster and faster as space grows bigger and bigger, producing more and more repulsion.
Einstein's fudge factor is strikingly similar to Hershey's fudge factor, in which those unfortunate souls who are addicted to sugary goodness tend to expand faster and faster, producing more and more repulsion to members of the opposite sex.
Scientific American Article (Score:2, Informative)
http://www.sciam.com/article.cfm?articleID=000F
Strings OMG!! (Score:4, Funny)
So what happens when God messes up on bounds checking, or memory allocation for strings?
Segmentation fault. Asteroid dumped *shudder*.
I guess we're lucky He decided to steer clear of pointers.
Re:Strings OMG!! (Score:2)
What do you think black holes and wormholes are?
You May Be Looking at a 5+5 universe, my friend (Score:2)
The universe uncurls from its current 3+1+6 configuration to a simple ten dimensional space-time continuum of lower overall energy. Depending on the divide error, one may end up with a simple 9+1 (9 spatial, 1 temporal dimension) universe, but for particularly eggregious errors we end up with 8+2, 7+3, 6+4, and even 5+5 configurations.
What one would want with 5 temporal and 5 spatial dimensions I don't know, but 5 te
My physical parameters (Score:3, Funny)
I'd like to think there's at least ONE universe out there where I'm skinny and good look'n!
"No pain, no... pain." Why don't we just leave it at that?
Re:My physical parameters (Score:2)
Re:My physical parameters (Score:2)
Good resource (Score:2, Redundant)
You can buy it here [amazon.com] from Amazon.
Re:Good resource (Score:2)
This one's way out there. (Score:2)
Anti-Anthropic Sky God Freaks (Score:3, Interesting)
Anyone remember the old Times headline? (Score:3, Funny)
Trade secret? (Score:3, Funny)
Re:Trade secret? (Score:2)
Existence of TOE (Score:3, Interesting)
At best I think that if we find a TOE it will have extremely poor predictive value because it will be so generic that it tells us not too much more about our universe than we already know, and simply give physicists new universes to wank around in. Not to say we shouldn't research this... ya never know where you might find useful stuff.
My String theory (Score:4, Funny)
The first string says to the bartender, "Give me a beer." The bartender turns to the second string and says, "and what about for you?" To which the second string replies, "I would also like a beer#@a9101gb230b81;kajf3#$B89*#(&)*13!$%#@$" and goes on and on spewing gibberish.
The bartender, shocked, asks the first string, "What is your buddy's problem?"
The first string answers, "Oh, you'll have to excuse him, he isn't null terminated."
He does play dice... (Score:3, Funny)
People with issues... (Score:5, Insightful)
String theory was proposed by Lord Kelvin, who started to investigate by developing a theory of knots, which was expanded by Reidmeister, and blossomed in the 20th century.
Einstein's special and general relativity were created to explain observed phenomenon that could not be explained by current theories. For special relativity, this was the constant velocity of the speed of light given by electromagnetism and confirmed by the Michaelson-Morley experiments. General relativity is a result of formulating Newtonian gravity in the field theoretic language used for unified electromagnetism. There were bits of data around indicating its necessity, though, such as errors in the perihelion of Mercury.
Quantum mechanics was similarly developed because of an incredible plethora of data. Thanks to Bell, we now know that (unless theory takes some really extreme turns), before an interaction with a "classical" apparatus, a quantum particle not only has unknown position and momentum, it actually doesn't have either. It's a subtle argument, but it's pretty well tested.
The motivation for string theory was to remove infinities in the fields which result from point-like particles. There is no physical motivation. String theory was not formulated as a theory of gravity or a grand unification theory. Those were bolted on afterwards as people noticed they could have sufficient degrees of freedom: you can build similar theories with straight up quantum field theory, and many people do for their life's work. So far the theory has produced one observable, which we already knew to far higher accuracy from quantum field theory. Pure number theorists get more physics as a by product than do string theorists. Supersymmetry and the Higgs boson are attempts to clean up mathematical holes, but they seem almost well motivated compared to the morass that is string theory.
String theory has driven a wedge between theorists and experimentalists in particle physics, and made it "unfashionable" to do serious theory that actually deals with reality. However, the popular press loves it: you can quote big sounding names and no one can nay-say them. Most areas of particle physics abjectly fail when it comes to explaining what you're doing to the layman.
Thankfully the pendulum seems to be swinging. At Caltech, their one phenomenologist has recently been absolutely swamped with pupils: string theory seems to be dying off at last.
Re:People with issues... (Score:3, Interesting)
Actually, string theory was originally formulated as a theory of the strong nuclear force. It fell out of favor once quantum chromodynamics was invented.
I had a really good String theory (Score:5, Funny)
Now all I have is a mess.
Everyone seems to be dying (Score:3, Interesting)
Along with BSD, trinity and internet.....
BSD has been dying for over 10 years.
Trinity died even before reloaded could hit the screen.
Internet has been dying for sometime now.
Executive summary (Score:3, Funny)
QED
Primer to get you up to speed on current theory (Score:5, Informative)
However, here's a spiffy chart of the current "standard model" [particleadventure.org] to help people get up to speed. Especially helpful for those who don't normally deal with Mesons and Antibayrons on a regular basis...
PBS Nova: The Elegant Universe homepage (Score:3, Informative)
Superstring theory is not the only candidate (Score:4, Informative)
No, no, ONE string walks into a bar (Score:5, Funny)
Historical perspective (Score:4, Informative)
Re:direct link (Score:2, Funny)
If you have already registered with them, IMMEDIATELY disconnect your computer and BURN it. You must, absolutely must create a barrier between yourself and the NEW YORK TIMES made of TIN FOIL. Do not use aluminum foil, it WILL NOT WORK! Place thi
Re:Contradictions (Score:3, Informative)