|Aug16-05, 09:41 AM||#86|
Is String Theory A Waste Of Time?
By the way thank you for informing us about Krauss book, scheduled to come out in just two months (October 20)!
|Aug16-05, 09:52 AM||#87|
Following Juan's pointer I went to Amazon and found Krauss book ("the allure of hidden dimensions, from Plato to String Theory") due out 20 october, but I also came across this!
All Strung Out
by Lee Smolin!
For sale at Amazon.co.UK, the price is 19.15 sterling.
Apparently the publisher Basic Books brought it out on 3 July.
|Aug16-05, 12:23 PM||#88|
Juan, I do not think it is a waste of time to show that something is false.
Interesting book, though!
|Aug17-05, 09:11 AM||#89|
|Aug17-05, 09:27 AM||#90|
You can be sceptic of my evaluation of the theory (that is not a problem for me). But my evaluation is, exactly, that string theory is a waste of time (and money). I could search other words for you but the message would be the same.
You are well-versed Marcus and probably know the history of Albert Einstein, who failed in his search to find a unified theory of forces in the universe, spending the last three decades of his life isolated from the scientific community.
Glashow (the Nobel laureate) said,
String theory is completely outdated. It is based in concepts and ideas of the 90s. To work in it is a waste of time (and money).
|Aug17-05, 10:18 AM||#91|
Telos, you are definitely on to something about time spent drawing testable conclusions from a theory so that it may be shown false.
|Aug17-05, 11:11 AM||#92|
In this thread, which Ratzinger started in June 2005, some knowledgeable PF people like Haelfix, selfAdjoint, Ohwilleke, concisely reported some reasons why there has been a decline, over the past 3 years or so, in interest and popularity of string research.
Increasing worry and pessimism among string researchers was reflected in the Toronto discussion video.
One encounters expressions of disillusion among graduate students---some of whom are changing fields---and symptomatic efforts being made by string-loyal bloggers (such as Motl and Distler) to shore up morale among the graduate students.
We also see some statistical indications of the decline in string interest, popularity, optimism. One can always argue about how to interpret the various statistical measures, however.
I must say that observing this string "downsizing" going on has increased my respect for the honesty and courage of certain researchers such as Andy Strominger. He made an excellent two minute statement in the Toronto discussion at time 1:28:20
It put me in mind of a story in the Bible where a general tells his soldiers that anyone who wants to can go home, and about half of them leave (this is called "downsizing"), then the remaining ones go on to win the battle.
Anyway Juan, I will try to say what I think about your message that string theory is a waste of time.
|Aug17-05, 11:30 AM||#93|
2. increasing numbers of people seem to be deciding that FOR THEM it is a waste of time, and so they are getting out of the field, or they are not writing so many research papers as they did. (However on arxiv I see a growing number of string papers by people at Beijing Normal and other large Chinese universities. These people do not think string is a waste of time for them and they are responsible for an increasing fraction of the research postings.)
3. your statement does not have a clear meaning unless you specify a waste of time AS WHAT. I think a lot of people would agree that string theory can lead to ideas and results that are interesting AS MATHEMATICS.
4. your statement would not apply to a mathematically gifted young person who goes into string and discovers something interesting and valuable AS MATHEMATICS. You cannot say that such a person is wasting their time!
What gives mathematics intrinsic WORTH is the interest it evokes from other mathematicians. It does not need to be a fundamental testable model of nature.
5. however your message, suitably qualified and restricted, is a very helpful one to have expressed---and voicing it actually DOES STRING THEORISTS A FAVOR by increasing the pressure on them to arrive at a nonperturbative background independent formulation that makes falsifiable predictions. This is the only way to be sure that string theorizing is not a waste of time AS PHYSICS.
|Aug17-05, 01:01 PM||#94|
|Aug17-05, 01:46 PM||#95|
|Aug20-05, 08:49 AM||#96|
As said, I do not think that the decline of string research program is just temporary one. In the past, there were difficulties but now people is seeing that each year original objectives of string theory are far, and far, and farther. String theory history looks like a divergent asymptotic series.
Now, let me reply your very interesting comments.
As said by Nobel laureate P. Anderson this year, string theory is a futile exercise as physics. I substituted “futile exercise” by “waste of time” but my evaluation of string theory continues being correct.
I would state that string theorists provide none serious argument why we would believe on string theory, only bold statements like "it is the most promising way" or wrong claims like "is the only was to quantum gravity". I see an injustice here with people that are not string believers.
Has string theory been interesting on mathematical topics? Of course, but that does not justify the hype around it and its study on physics dept. Moreover, let me say that the impact of string theory in the whole of mathematics is not so huge, at least, it is not more important (by orders of magnitude) that impact of some field theoretical techniques. For example, contrary to popular belief, Fields Medal awarded to Witten was not by the application of pure string theory methods to math, most of mathematical work of Witten was from field theory. Atiyah, who is many times more smart and versed that i in these topics, affirms that string theory has had an impact on mathematics which has been really quite extraordinary. Well, he said that in a popular interview. However, far from popular claims, I see not radical advances on mathematics as provided by the own Atiyah on "index theorems" (theory of quantum operators in quantum field theory).
Do not forget that LQG is claimed background independent whereas continue to be an “inefficient” approach to quantum gravity. In fact, there is no possibility for obtaining a consistent classical limit converging to GR after of 40 years from Hamiltonina gravity: geometrodynamics, Astherkar QGR, LQG, etc.
Smolin, as others loop theoreticians, assumes that relationism is correct, but it is not as already said. The idea of that causality becomes a fuzzy notion because of fluctuation of light cones is completely wrong.
|Aug20-05, 12:36 PM||#97|
i am sure strings are going to disappear and first sign of this is the idea os landscape of vacuua. it is such a comic trash that during seminar you feel like quiting physics because such are the things promoted as future directions.
but stringers cannot fool th world much long and more so because some of them are serious researchers with a conscience still alive.
plase read freeman dyson: disturbing the universe and you will know hy string theory qualifies as a failure.
The problem of delay in this being branded a failure is obvious, INERTIA. there are too many researchers persuing it who are trained as stringers unlike the masters who were all high energy physicists. S now we have this young generation of ignorant people who doesnt even know where to find mistake to stop doing it since they simply do not know physics. It is just poor quality mathematics.
|Aug20-05, 01:04 PM||#98|
"...serious researchers with a conscience..."
Public support for physics ultimately depends on the trust that nonspecialists have in the self-critical, "self-policing" ability of theorists to remain engaged with empirical reality. So your perception that there are some who are not indulging in a mathematical escapade is very important.
|Aug20-05, 01:15 PM||#99|
Among tested, well-established theories, General Relativity is the most background independent model we have. When quantizing Gen Rel, it is obvious to try to preserve the B.I. feature if one can. The comparative success or failure of various attempts to do this is not relevant to the validity of the effort.
With both String and canonical Loop experiencing difficulties, one sees that it is actually the most background independent approach that is currently making the most progress.
|Aug20-05, 02:48 PM||#100|
On Strings I feel it’s future may well becoming a waste land. But I believe it has been very valuable in identifying the 11 dimensions issue. Lack of progress indicates that this idea is likely just wrong. But ANY future theory that proves 11 D as wrong, should also be able to explain why the 11 D issue appeared to be viable at all. Just this additional ‘test’ of future theories, I think that can be worth quite a bit.
Also, You mentioned something else I could use a little help on “how I think”
Your comment tells me I need to Fine Tune my thinking a bit. Does the following make sense:
SR Special Relativity - background dependent
Works on a ‘dependant’ background of space and time in a classical manner. Just the Newton formulas were inadequate and the measures of space or distance over time need to be understood by the better formulas provided by relativity.
GR General Relativity - background independent
The use of a warping of time and space into “space/time’ to understand gravity, releases us from a background dependent measure. That is the physics we see, relativity included, is not dependent on any background traceable measure in either distance. But rather only dependent on the “relationships” between physics events that cannot be tied down to a measurable background reference of space and time.
A fine point but seems an important one I’d not fully recognized.
In a similar fashion :
Quantum Theory - background dependent
Quantized the minimum amount of energy to be found in light “packets” now photons. And set minimum size of change in measure we could expect to ever make in both time and distance (space). Natural limitations associated with this made near impossible to make significant progress until.
Quantum Mechanics - background independent
Instead of “warping” the relationship of time and space, used the uncertainty principal to allow measure and predictions at the quantum level to become understandable.
Thus one way to explain the inability of combining the physics of QM and GR even though they are both “background independent” is that they arrived at their independence in dramatically different forms (warping vs., probabilities) that we so far have been unable to interrelate.
(I'd previously considered not being able to combine the two as a dependent vs. independent issue)
Is this a reasonable tune up to my thinking?
Let me know if I’ve gone off track on the “background” issue as it is a bit new to me.
Also are there any other “well-established theories” that arrive at their background independence though some other manner than GR or QM? I’m assuming that most all, like M-Strings, have their foundation in QM.
|Aug20-05, 03:27 PM||#101|
does anyone have an Intro to D.G. or Intro to Manifolds link?
Randall there are two abstr. math. ideas you need that are actually very simple and easy to get-----Manifold and Metric-on-the-manifold.
For 150 years the fundamental paradigm for a continuum that everyone uses is a Manifold (defined by Riemann around 1850).
the most common meaning of B.I. is you start with a Manifold without a metric.
in a B.D. theory you start with a manifold and give yourself a metric on it to start with as well
have to go back later
|Aug20-05, 04:03 PM||#102|
Randall it is soooooo simple. I wish you would take a moment and think it over and come back and say honestly that you understand perfectly clear as day.
the reason we accumulate math concepts over the decades is ultimately MENTAL ECONOMY. they make thinking more efficient. and this is a case
the fundamental object in D.G. is the manifold which corresponds to the idea of a continuum without geometry. it is a blob that has coordinate functions defined on it
(local charts that are smooth and compat where they overlap)
but does not have any dingus or appliance that can tell you the distance between two points
because it has coordinates, at any point on the manifold you can explore all the possible directions in which you can take the derivative!!!!!!
All the possible DEE-EXES, and when you think calmly and patiently about this for a while you realize that this collection of all possible dee-exes IS the tangent space. it captures the essence of what we want the tangentspace at any give point to do for us. and it is intrinsic (defined without reference to anything surrounding the manifold)
this is a fundamental Idea of Western Civilization, like the freedom of the individual and the rule of law etc. this is the Idea of the Continuum which has been standard for 150 years
It is INTRINSIC. it doesnt have to be embedded in any larger space for you to know its tangent space at each point and be able to do calculus etc, and it STILL HAS NO IDEA OF GEOMETRY built in.
to do geometry you introduce a "metric" gizmo which is a bi-linear dingus defined on the tangent space at every point blah blah
and once you have a metric g(m) defined at every point m of the manifold then you can compute distances, angles, areas, volumes etc.
The most common meaning of B.I. is that you start with a manifold without a metric.
In Gen Rel you start with a 4D spacetime manifold and some matter and you set up this equation and Presto! you PULL THE METRIC OUT OF THE HAT! (EDIT: selfAdjoint objects to the wording. I mean that you solve for the gravitational field, which is the metric. more discussion of details of this in later posts...)
the metric, or geometry, can be totally freeform and it is determined dynamically by interaction with matter through the equation of the model.
This is VERY DIFFERENT FROM perturbative STRING THEORY where they start with a manifold that already has a prior-chosen metric defined on it.
Having a prior chosen metric lets you define the twangy equation by which the little thangs be vibratin'. Without that prior metric you got nothing to start with, stringywise.
|Similar Threads for: Is String Theory A Waste Of Time?|
|Time in String Theory||Beyond the Standard Model||5|
|Space-time in string theory||Beyond the Standard Model||4|
|String Theory: peace in our time?||Beyond the Standard Model||47|
|the quanta of space and time in string theory||Beyond the Standard Model||0|
|is space and time quantized in string theory?||Beyond the Standard Model||4|