25 December 2010

Supersymmetry - the oldest prejudice

Supersymmetry was invented in the 1970s with the aim to find a symmetry that contains both gauge symmetry and space-time symmetry. To achieve this combination, supersymmetry assumes the existence of fermionic coordinates. This assumption is so bizarre, so unrelated to experiment, and so frequently repeated, that it has to be called a prejudice.

The issue that supersymmetry tried to address, the combination of gravity and gauge symmetry, remains important, of course. But the last 4 decades have clearly shown that supersymmetry is the wrong solution to the problem. Why is it wrong? It is wrong because coordinates are not fermionic; supersymmetry is the wrong solution to the problem. But supersymmetry is also wrong because it is born from the prejudice that fundamental physics need to search for higher symmetries; supersymmetry adresses a problem that is itself born from a prejudice.

Fundamental physics will not get out of its present impasse until people recognize that theories have to be built on data, not on prejudices.

24 December 2010

Hermann Nicolai and points

Hermann Nicolai knows all people working on fundamental physics and is respected by all researchers for his work and insights.

In his presentations, he always stresses that a theory of everything must get rid of points in space; he explains that keeping the concepts of point and continuity is the reason that quantum theory and general relativity cannot be unified. In the tone of this blog, points and continuity are prejudices that have no experimental and theoretical basis.

Many people cannot agree. Among them is Nicolai himself. His own work on unification, around the Lie group E11, is based on points and continuity.

The moral of this story? Getting rid of points and continuity, and of prejudices in general, is tough.

23 December 2010

Weinberg and the Higgs boson

In the December 2010 issue of Scientific American, Weinberg is asked: Does the standard model require the Higgs boson? He answers more or less: [the standard model] requires SU(2) to be broken.

In other words, the standard model does NOT require the Higgs boson. Wow, this is quite a blow to many people, and to their prejudices. Let us see what results all the ongoing experiments will bring us.

22 December 2010

The false beliefs of Mike Duff

Mike Duff, a seasoned string researcher, has now proven publicly that he prefers wrong beliefs over facts. As Peter Woit points out, Duff writes in letter to New Scientist:

... the modern-day ramshackle alliance between unqualified scientists, the blogosphere and many science journalists when confronted with the academic consensus of superstrings and M-theory as the most promising candidates for unifying gravity with the other forces of nature. These people are quick to cry "this is not science", while themselves resorting to pseudoscientific alternatives. 

There is no "academic consensus" on string theory. In fact, physics is about agreeing with experiment, not with "academic consensus". This way of reasoning - by the authority of the consensus - is typical of the times before modern science existed. No true scientist reasons in this way.

Worse, this complaint is written by somebody who in his talks always mentions the "multiverse", the most stupid concept ever introduced: a concept that cannot be defined properly (what is the difference between this universe and that universe?) and that cannot be proven by experiment. Whoever believes in the "multiverse" is an unqualified crank, not a scientist - and not even a pseudoscientist.

Obviously, Duff is nervous, because string theory is a failure, and he has devoted his life to it. We see from his writing that string theory has become a religion; nobody drops a religion if it makes wrong statements, because a religion is part of your value system and gives you strength and hope. But does string theory really deserve to be a religion? Why do so many people promote it to a belief system? Any pastor, rabbi or priest would be apalled when seeing this.  "Thou you shall have no other gods before me." Nevertheless, for some people, string theory has become another god.

21 December 2010

Mathematical difficulty

It is repeated over and over that the theory of everything requires complicated mathematics. This belief is so common and so deep that it is rarely challenged.

Why do people believe this? Is there the hidden idea that the world is complicated and difficult to understand? In the past centuries, physics has shown the opposite: time after time it was discovered that the world is simple. So the evidence points in another direction.

The belief that the theory of everything is complicated to understand is yet another type of ideology, contrary to all evidence known so far.

20 December 2010

Stringy black holes

In his latest post, Motl concludes:

String theory predicts that the light black holes have masses that are almost certainly relatively close to the Planck scale, to say the least, and will never be produced by particle accelerators. It's the other "alternative" theories that are driven by hype rather than good science and that have predicted lots of flashy phenomena - that are not being seen and won't be seen as the dust is settling and string theory is proving to be the only beyond-QFT framework with a lasting value.

Ideology is rampant again.

First, every serious theory of fundamental physics predicts that black holes have masses above the Planck scale. Second, string theory is not the "only beyond-QFT framework with a lasting value": there are many more. In fact, string theory is based on the assumptions of supersymmetry and of higher dimensions, both of which have no experimental basis. String theory itself is not of lasting value.

A faithful reader of Motls blog once emailed in disbelief: Motl is not able to explain to a normal reader with a physics degree where the assumption of higher dimensions comes from. My answer is simple: if higher dimensions cannot be explained to your own faithful, who is suppose to believe in them? "Believe" is the right term here, as experiments give no hint at all.

But this does not mean that Motl is always wrong. In fact, many of his arguments against other "theories" of fundamental physics are correct. His "down-to-earth" approach of physics is shared by many great physicists.

About the electroweak "unification"

Libraries are full of books claiming that the electromagnetic and the weak interactions have been unified. That is wrong! The two interactions mix, but they are not unified. They are different things, remain different, and their coupling strengths remain described by two independent parameters.

This widespread mistake had disastrous consequences. People went around for 40 years saying: we have unified the first 2 interactions, now we will unify them with the 3rd, and then we will include the 4th. Unfortunately, this approach cannot work, because the first 2 interactions have not been unified to start with.

Despite this false direction, unification is what fundamental physics is about. But so far, nothing of the sort has been achieved for any of the four interactions. The idea that the electromagnetic and the weak interaction have been unified is an example of ideology: it contradicts the facts.

19 December 2010

Garrett Lisi and the TOE

Garrett Lisi is a hero of theoretical physics. He is a hero because he is one of the few that has a clear and open goal: to find the theory of everything.

Why does this pursuit make him a hero?  Because there are hundreds of people who pour their vitriolic comments over him. Despite them he goes on working, undeterred by this hostile environment, and pursues his goal.

The most despicable people are these commentators. They are jealous of his dedication, of his optimism and of his courage. And they are full of ideology: they dislike his approach because it does not contain supersymmetry, higher dimensions of space or some other of their pet ideas that are unsubstantiated by experiment.

In contrast to string theory and all those other "theories", Lisi makes predictions that can be compared with experiment. Let us see what comes out of it. We should always remember that Lisi is honest, open and willing to confront reality. His critics are not.