Monday, November 12, 2012

Death of Supersymmetry: Experimental Evidence against the Theory

Many of you may have already heard about the very recent evidence against the theory of supersymmetry (i.e. that there are massive super-particles for every particle found so far. In supersymmetry, for every boson there's a super-symmetric fermion, and vice versa. Supersymmetry is also an underlying component of most string theories.)
Here are links to a few articles in the public media regarding the latest evidence against supersymmetry:
BBC news article
New Scientist article

Here's a link to a recent article I wrote on the Death of Supersymmetry and String Theory. In the article, I mentioned that I would start adding more of the details about the experimental evidence against supersymmetry. Rather than just edit that article, I figured that I'd just make a new article and link to sites with the latest evidence against supersymmetry.

http://www.math.columbia.edu/~woit/wordpress/?p=5013
BBC news article from Nov 2011 on similar topic
http://www.math.columbia.edu/~woit/wordpress/?p=5272
http://www.math.columbia.edu/~woit/wordpress/?p=3937
http://www.math.columbia.edu/~woit/wordpress/?p=4171


Follow the links from these sites to see the actual data that suggests that there are no particles in the energy ranges that would allow supersymemtry to answer the questions that it was initially designed to answer, such as: how are gravity and quantum dynamics related? And what is the source of dark matter?

This means that we need to re-think what could be the source(s) of dark matter. My educated guess is that it's probably lots and lots of neutrinos (see the following article.) In addition, if dark matter were neutrinos and if irreversible collisions between particles interacting via the weak nuclear force caused space-time to expand, then we might have our explanations for both dark matter (i.e. matter that only interacts via gravity and the weak nuclear force) and dark energy (i.e. the expansion of the space-time 4D sphere via the increase in entropy by weak nuclear irreversible interactions.) You can follow the links in this paragraph to read articles in which I suggest that we need to move beyond supersymmetry and string theory in order to posit why the universe is expanding and why entropy increases with time. To do this, we need a law of physics that is time assymmetric. One of the many problems I have with supersymemtry and string theory is that these theories do not definitively state whether the universe is time symmetric or time asymmetric.

As a further discussion on the topics raised in the post of Death of Supersymmetry and String Theory: Saving the Physics Community from Nihilism, I wanted to attach a link to a comment I recent make at the website Cosmic Variance by Sean Carroll. While I've had some negative things to say about Prof Carroll. I do want to point out that he is incredibly knowledgeable in the topics he teaches and that he is a very good teacher. My problem is with his philosophy of extreme relativism and boarder-line nihilism, and with that fact that he seems to be supporting supersymmetry and string theory well past the point in which it is healthy to support any laws of nature, let alone a theory with no evidence.

So, here's a link to one of his more recent articles/lectures on the laws of nature and the meaning of life, and my comment below:  (You'll have to read the article to understand what are Claims#1, #2 & #3.) My goal in writing the comment below was to remind people that the physics community can save itself from a descent into nihilism, but to do so, it will have to develop a new philosophy of life that is consistent with our known laws of physics, chemistry, and biology. At the end of the comment, I suggest to readers that they ask themselves the question: "How is language and communication possible without a reference to some absolute, unchanging notion such as ethics, mathematics, self-reference and symmetry?" The experimental evidence against supersymmetry is a call to save the physics community from its descent into meaninglessness, multi-verses, 10-D universes, and time symmetry.
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Sean,
As stated by others, your Claim#1 (that we know everything as of 2012) will likely be proved false in 2013. I’m not sure if you’re trying to be controversial on purpose, but this is over the top.
Claim#2 is a philosophical statement (i.e. that there is no meaning.) Try proving this statement mathematically. I guarantee you that, in trying to prove your statement, you will inevitably create a self-referential, self-replicating loop.
Claim#3 is simply a restatement of Existentialism.
Are you prepared to defend the logical consequences of your existentialist philosophy?
If there is no objective meaning in life and if we create our own meaning, then you have no means of making moral, political argument. You’re basically stating that there is no absolute criterion to judge whether an action is ethical. If meaning is not objective, then why do you seem to get so upset with people who hold different philosophies? The reason you get so upset with other people’s beliefs is that there actually is an underlying, unchanging, absolute ethical foundation within the universe.
I think that you want to have and eat your cake as well. I think that you want the freedom to be an existentialist/atheist, but you want the luxuries generated by a society that values hard work, i.e. a society who believes that hard work and growth (via improved science and technology) are the goals of life.
You claim that people can invent meaning, but where is your “Theory of Personal Meaning”? Can you describe the physics, chemistry or biological of your statement, “whatever meaning our lives might have must be created by us”? How exactly do we ‘create meaning’? While I understand that you don’t like how certain religions took and deformed Plato’s theory of an intangible, real world of abstract notions like ethics and mathematics, there is still a lot to learn from Plato. For example, Plato argues that the ability to communicate via language is only possible if we have a means of referring to unchangeable abstracts like ethics and mathematics. Do you have a means of either proving or refuting Plato’s claim? I think that we have a means of proving his claim, but I’ll grant that most proofs aren’t air-tight.
It seems that you are trying to bring together the disparate philosophies of materialism, existentialism, and utilitarianism. You seem to think that these disparate philosophies can be brought together in some pluralistic, scientific, modern, atheistic and utilitarian society. But that is just the philosophical air you are breathing right now. This will change because we are learning so much about how the universe is not deterministic, not time-symmetrical, and not reducible to particle physics. Materialism, nihilism, utilitarianism, and existentialism are dying philosophies because they just don’t describe our time-asymmetric universe, in which the future can not be predicted from current conditions (even if you knew the position and momentum of every particle.) These philosophies are remnants of a Newtonian/Laplacian belief that all of the laws of nature were deterministic and time reversal symmetric, which therefore led philosophers like Diderot, Bentham and Nietzsche to suggest that we had to invent meaning, such as individual or societal happiness.
I suggest that you refrain from philosophical statements that can’t defended any longer because the effects of these existentialist and utilitarian philosophies are causing real-world negative effects on the economic and population growth rates in most ‘Western’ countries. Your attempts to justify “personal meaning without objective meaning” will do damage to the scientific communities ability to communicate with the people who fund science through their taxes. This will damage our ability to conduct science, and in the end, damage our ability to use science to help society grow. Ultimately, the growth of life in the universe should be the goal of our time and effort because it appears to be the only goal that consistently has been compatible with the known laws of physics, chemistry and biology even as our understanding of the laws has changed.
Your support of string theory, multi-verses, and supersymmetry without any evidence for these theories is bad enough, and has already done a lot of harm to the ability for physicists to get public funding of their research. But your vocal support of existentialism will likely do even more harm to the physics community. It’s one thing if you were just discussing experimental physics and the possible theories that fit the experimental data (such as in your Great Courses lectures), but for a few years now, you have been going well outside the realm of your expertise. Be careful you don’t do more harm than good.
p.s. for those of you who are reading this post and understand what I’m saying (even if you don’t agree), think about what it means that you are able to understand these words. How is language and communication possible without a reference to some absolute, unchanging notion such as ethics, mathematics, self-reference and symmetry?

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