Apple Boy: Hi, G-grandmother. Professor Matt Strassler had a new post on string-theory. It truly gives a perfectly detailed description about the string theory. But, most importantly, he laid out the issue of SUSY by categorizing it into three groups.
- Natural supersymmetry (related to the Standard Model unnatural problem) — testable at LHC.
- Supersymmetry proper (not related to Standard Model or anything else) — could exist at very high energy places, far, far, far out of reach of the LHC.
- Supersymmetry of string theory — that doesn’t mean that it shows up in a simple way: it is not necessarily the case that there will be a recognizable superpartner particle for every particle, as traditional supersymmetry predicts.
I have two questions for you.
- Is there any supersymmetry in Nature-master’s file box?
- How can people on Earth rule out the case 2 and 3 if they are wrong? Per Matt’s saying, we have no way to rule them out if they are simply wrong.
G-grandmother: This morning, I did peek into Nature-master’s file box. I did see a *supersymmetry* folder, but I cannot find anything about SUSY (with s-particle) or anything about the *supersymmetry of M-string*. But, the answer for your second question can also be the answer for the first one. There is no need to rule them out. As soon as the correct answer is showed to them, they will simply *trash* the others, not wasting one more second on them regardless of whether they are right or wrong. They call it the Occam’s razor, you know.
Apple Boy: So, all is hinged on the right answer. But, again two questions.
- Does anyone (besides the Nature-master himself) know about the right answer?
- How can he convince others about his answer being the right one?
G-grandmother: Good questions. But, it is not real that big deal. The first step is pointing out the wrong answers, the weeding out, you know. Using string theory as an example, it should have two missions.
- Making contacts with the knowing physics, that is, reproducing the known SM particles, especially the 48 matter particles.
- Understanding the old mystery. Gravity was kind of mystery. By *fully* understanding the gravity, it will open up the gate for the *Super unification*.
If string theory does not have the two missions above, it will be no value of any kind as a physics theory. Yet, we all know that it failed on both missions. As we discussed before, the *dark energy* plays 2/3 parts in gravity. Yet, before the discovery in 1998 that the universe’s expansion is accelerating, string theory had no slightest clue about it. All the arguments about whether the string theory has any great *predictions* or not is not very important, as it is already a *failed* theory in terms of the two missions above.
Apple Boy: So, all is hinged on the dark energy now. A five year plan for the Dark Energy Survey was lunched last week. It is an international collaboration using the Blanco telescope in Chile to study the effects of dark energy on the evolution of the universe through a variety of probes — supernovae, baryon acoustic oscillations, weak gravitational lensing, and counts of galaxy clusters. But, G-grandmother, you have hinted repeatedly that the dark energy is not a mystery but is a piece of cake. Can you elaborate on that a bit more?
G-grandmother: The dark energy itself is not a mystery, but the story around it was a bit entangled. You know, Einstein came upstairs not too long ago. I put up a welcome-wagon party just for him. We are now good neighbors and friends. We often had good party together. But, one time, I talked to him about the dark energy after I learned it from your brother, and he began to weep. What is the matter, Mr. E, I said. Remorse, remorse, he replied. Oh, Mr. E, Nature-master gave everyone a timer when we went to Earth. When the time up, we have to come back, dropping all the unfinished work behind. You have done so much for the mankind with your SR (special relativity) and GR (general relativity). It is truly not a bit problem for your not knowing the dark energy. But, he bawled even harder and said, “Misled, misled”. Misled of what? I asked. We all know that GR is not complete but still very thankful. Yet, he kept weeping. Is anything about SR, I asked. He nodded. Is an upcoming experiment going to invalidate the SR somewhat? No, he murmured. Then, what is the problem? I asked. “Misled, misled” he murmured. Misled of what? I asked again. He turned in and did not want to talk about anymore.
Apple Boy: Wow, a truly weird story, entangled indeed. But, we can get three points from this story.
1. Einstein is confident about the SR to stand all experimental tests.
2. Einstein is remorseful for SR having some sort of misleading karma.
3. The misleading of SR is related to the dark energy.
Am I right? G-grandmother. Can you talk about the dark energy now?
G-grandmother: Your analysis is the only one that I can came up with too. Now, after thinking about Mr. E’s weeping, I am exhausted today.
The followings are comments that I made at Matt’s blog post “Am I misleading you about string theory?”
Comments 1: Matt: You are always fair and clear on your point. No, I was not misled. The *mislead* is a very important issue which has never been discussed before, and it has the dire consequence for the advancement in physics, especially for this *final* step. It was so accidental that I did discuss the *misled* issue in my comments at your last post. There are two types of mislead.
1. Mislead by wrong information — this has no long time effect.
2. Mislead by *right* information — this could be very, very harmful with dire consequence, as the bright *right-lights* can blind the view to the next gate.
In your case, you were not misleading, no misleading of the either types. The whole thing was just a bit too emotional. Woit’s reason of against string theory was a bit too shallow. But, for the public in large, they have given the string (M- or F-) theory 40 years to success, but it has failed to make any contact to Standard Model, the only criterion understood by the lay public. This *single* point is enough to convince the public that M- or F- theory is nonsense although the string theorists still form a very powerful institution. This is why Woit has his market.
Woit put a *bet* on “M- or F-string theory is nonsense in terms of physics” and is confident that he is going to win that bet for the reason that those are now obviously failed theories. The fact is that he is obviously winning the bet thus far, and the public at large are betting the same thing with him.
Yet, the string theorists are still forming a very powerful institution, no one dare to shake it. This makes Woit a great hero in the public eyes.
By reading Matt’s original post, he was very fair-handed. By using the hammer analogy, he hinted that the string theory (perhaps, the M-theory types) might not be a viable physics theory but is still good tool for doing many other works, as good as a hammer.
Then, the debate on the *Predictive-ness* issue made him (Matt) as a string theory strong supporter. This is not what I got from reading his original post.
For the string theory debate (the M-theory types and the likes), my view is very simple. Any theory beyond Standard Model must make contacts to known physics. The M- or F-string theory has failed on this simple criterion. This failure goes way beyond the *semi-decidable*, the answer is at just beyond the next corner. No, the predictions (even zillions) beyond the next corner will not help one bit on their failure of not being able to make contacts to the known physics.
With the hammer analogy, I must agree with Matt here.
Comments 2: In my previous comments, I have said that I was not misled by Professor Matt Strassler. As his post is very fair and balanced, I do not think that it can mislead anyone although there are a few commenters saying otherwise. The whole issue is about the M- /F-string theories and SUSY (with s-particles) have misled the entire mainstream physics for the past 40 years. As it should be, the central debating point is about *predictive-ness*. But, it again got into the nitty-gritty, becoming meaningless. I am quite sure that many laymen can agree with me on one point about this predictive-ness issue.
a. Any prediction in or about the Alice Wonderland is nonsense. Any theory beyond the Standard Model must *predict* the known physics (that is, making contact to it). In this case, it must reproduce the particle zoo of the Standard Model. Both M-/F-string theories failed on this simple criterion after 40 years of trying. That is, they are trashes in terms of *physics* regardless of whether they are made of pure gold or not.
Woit’s arguments against M-/F-string theories, SUSY (with s-particles) and multiverse are quite weak as he does not have the *correct* answers in his hand to replace those *wrongs*. But, his courage of fighting against a super powerful institution (formed by many big names of M-/F-string theorists and SUSY devotees) single handed made him a great hero in the physics history. I personally do not like his abrasive personality but still must give him my salute for his courage and the great deed done to physics.
This debate can only be resolved by having the *correct* answers for the mysteries of the universe. As Professor Matt Strassler said, “You need to unify at least hypercharge and weak isospin with gravity if you want to play that game.” Yet, without knowing what the gravity is, any next step becomes meaningless. Today, we are kind of knowing that gravity consists of three parts (visible mass, dark mass and dark energy). Fortunately, we now have the Planck data (dark energy = 69.2; dark matter = 25.8; visible matter = 4.82). Thus, any theory which *predicts* those simple numbers will be a viable theory for these mysteries. In my view that the dark energy issue can be easily resolved by answering two conceptual questions.
1. Where is the edge (boundary) of this universe?
2. What is the outside of that edge (boundary)?
Knowing the answers of these two conceptual questions, they can then be translated into equations. Then, this debate will reach a conclusion.
The above is also available at http://profmattstrassler.com/2013/09/17/did-the-lhc-just-rule-out-string-theory/#comment-86318