Gross Calls String Theory A Bizarre Science That Is A Dangerous Business

In summary, the conversation on the Woit blog discusses the controversial topic of the Landscape theory and its validity as a scientific concept. Physicist David Gross is quoted as the only one who recognizes the Landscape as pseudo-science and argues that its inability to be disproven makes it unscientific. He also suggests that the frustration of string theorists in not being able to make predictions has led to the emergence of the Landscape theory. The conversation also raises questions about the inclusion of pseudo-science in physics forums and the credibility of scientists who criticize string theory without proper understanding of it. Age and experience are also mentioned as factors that may influence one's perspective on the validity of theories.
  • #36
Demystifier said:
As I already said once, asking string theory to explain the Standard Model of "elementary" particles is like asking quantum electrodynamics to explain life on Earth.

Are you intending to be ironic or is it a defense of the anthropic principle?

Let me do my try:

"asking Planck scale string theory to explain the Standard Model of "elementary" particles is like asking QCD scale string theory to explain gravity".
 
Physics news on Phys.org
  • #37
arivero said:
Are you intending to be ironic or is it a defense of the anthropic principle?
It is a sort of the defense of the anthropic principle. More precisely, it is an argument that it is quite natural that a fundamental theory contains a huge number of different solutions, so that it cannot really explain why we live in a very specific solution in which we live. A "theory of really everything" should be also a theory of the initial conditions, which string theory is certainly not supposed to be.
 
  • #38
Demystifier said:
A "theory of really everything" should be also a theory of the initial conditions, which string theory is certainly not supposed to be.

Indeed it seems that the label "Theory Of Everything" implies, to laymen, more than the strict goals of understanding the Standard Model and -perhaps- gravity. The old label "Grand Unified Theories" was perhaps more concrete: we are interested on the "guts" of the animal, no more.
 
  • #39
I am sure there must be some value in all this across the garden fence chit chat, or you very cleaver guys would not be indulging in it but , does it solve anything?

Addition

I can remember when we had engineering meetings to resolve a problem, they proved quite useless, it was found that a single observation, of one guy solved the problem.
 
Last edited:
  • #40
Exactly! And it is to David Gross' credit that he is one of the few (sometimes it seems the only) prominent figure within the string club who is willing to speak out publically against the direction taken by Susskind and many others.

Well, Lubos Motl and Jackes Distler are totally agianst landscape and they publish routinatelly in their journals about it. I guess they are, at least, relativelly prominent figures. There is also something called "Swampland", a program initiated by horava (or another well known figure in strng theory, I have no time now to verify it) which is something like a program against landscape consisting in the search for selfconsistency of low energy effective field theories with the full strig theory. This puts more realisitic limits amount the really obtenaible vacua.

The two more recent books on string theory, Michel dine "Supersimmetryand string theory" and Becker, Becker, Schwartz: "string theory and M-theory" have an introduction to the landscape but they are very coutous about it´s actual convenience. I wouldn´t say that the string landscape could be considered a signature of the viewpoints of most people working in string theory (fourtunatelly).
 
  • #41
Demystifier said:
It is a sort of the defense of the anthropic principle. More precisely, it is an argument that it is quite natural that a fundamental theory contains a huge number of different solutions, so that it cannot really explain why we live in a very specific solution in which we live. A "theory of really everything" should be also a theory of the initial conditions, which string theory is certainly not supposed to be.

A theory of everything is not expected to be a theory of contingency (I do not see a meaning for the latter, btw). There are many solutions (different orbit configurations) for the gravitational problem. The fact that, e.g., Mars currently has a given orbit does not depend on any intrinsic necessity, it is purely contingent. But the fact that its orbit fits an ellipse indicates the acceptability of Newtonian gravitational theory as a correct description of the physical phenomenon involved (under the domain of validity of the theory). What is the theory that "shapes" the masses of particles?
 
  • #42
ccdantas said:
A theory of everything is not expected to be a theory of contingency (I do not see a meaning for the latter, btw). There are many solutions (different orbit configurations) for the gravitational problem. The fact that, e.g., Mars currently has a given orbit does not depend on any intrinsic necessity, it is purely contingent. But the fact that its orbit fits an ellipse indicates the acceptability of Newtonian gravitational theory as a correct description of the physical phenomenon involved (under the domain of validity of the theory). What is the theory that "shapes" the masses of particles?
Quite a penetrating observation, Christine - not that I'd expect less of you. The fact that an ad hoc modification of Newtonian gravitation (MOND) has predictive power that correctly described the gravitational behavior of low-surface-brightness galaxies a decade before their observation illustrates that theory can be made to conform to observation. In no way does it address the foundational physics, though, so though that modification appears to work in galactic domains, we still don't know why. At least MOND works for a broad range of spiral galaxies, and that range of applicability (generalization) is promising, though I expect that the modification addresses some foundational physics that is as-yet not understood.

Somehow, I'm always drawn to the LQG side of the force (cheesy Star Wars reference) because there are hints (including recent MAGIC observations of possible energy-dependent variable c) that the LQG folks are on a productive path, especially in regard to describing some fundamental quality(ies) of space. In comparison, String appears allegorical and hard to pin down. I know it is popular and well-funded, but the engineer in me wants mechanics based on observables.
 
Last edited:
  • #43
ccdantas said:
What is the theory that "shapes" the masses of particles?

The point is that the masses of the particles are known to be suspiciously regular, with exactitudes beyond the law of low numbers or the birthday paradox. So it is hoped that there is some theory shaping the masses.

String theory aimed to this niche two times: first at QCD energies, and then going up to Planck but claiming contact with GUT theories and renormalization group running from high to low energy. And due to he closeness between Planck scale and GUT scale, for sure every theory of quantum gravity tries to claim some possibility to fix the masses. I think it is a bad idea; in the low energy regime almost everything points to the electroweak scale, the only two exceptions being 1) The GUT running of coupling constants and 2) the neutrino seesaw scale.
 
  • #44
ccdantas said:
What is the theory that "shapes" the masses of particles?

So, let's say we looking for a theory. Then one can ask what is the method that shapes our theories? Then we are apparently looking for a theory of the evolving theories, aren't we?

Or is everyone satisfied with the ad hoc method, combined with the falsification selection method?

Opinions?

/Fredrik
 

Similar threads

Replies
76
Views
23K
Replies
34
Views
14K
Replies
31
Views
7K
Replies
4
Views
5K
Replies
18
Views
5K
Replies
8
Views
5K
Replies
7
Views
5K
Back
Top