Time is running out for supersymmetry and string theory [video]
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There is a plan. They are looking for particles which supersymmetry says they should find. They haven't found them. Supersymmetry needs supporting evidence but they're running out of places to look.
Yes and no. It is important to understand that theoretical predictions with regard to particle accelerators are often massaged into making predictions that seem to coincidentally help justify the cost of the next big accelerator to politicians and nations.
It would be different if this belief was pushed by a few isolated theorists, but it's the major focus of the field and they will likely ask for billions of dollars of new public investment for accelerators to continue the goose chase, with no promising leads from any of the previous experiments.
Some people argue that since so much of the supersymmetric theory parameter space has been ruled out, that this reflects negatively on supersymmetry as a whole. However you must understand that this is exactly the kind of non-empirical argument that some stringers get so much flak for deploying. Nobody knows what the prior distribution should be over parameter space and it is not possible to do something like applying a uniform distribution, because if you do something as simple as algebraically re-arrange the parameters the uniform distribution over the new parameters will not be equal to the uniform distribution over the old parameters.
I can give you a concrete example to illustrate the fallacy of trying to measure the "volume" of the ruled-out parameter space. Suppose there is a grain of rice somewhere on a chessboard, and you are trying to find it by asking a person who can see the board whether the grain is in zone 1, zone 2, and so on. You count all the way up to zone 63, and the person who can see the board says "no" to every query. You conclude that if the grain is not on 63/64ths of the board it is unlikely to be on the board at all. Later, you happen to walk in to the room with the chessboard, only to discover that the man in the room had drawn a weird grid that mapped zones 1 through 63 to different parts of square A1, and mapped 64 to the entire rest of the board.
Quite to the contrary, I was arguing that a uniform distribution over parameter space was impossible to define.
The way it is supposed to work is adherents of a theory give it up if it can't make empirical predictions and another theory comes along that can.
However at present we don't have a alternative theory that is doing that, so string theorists are free to hang onto their theory, in spite of the lack of empirical proof.
Of course, many string theorists nowadays say that empirical proof is not necessary for proving a theory. That would seem to imply that if an alternative theory made a number of correct predictions that string theory can't, that would not be a reason for abandoning string theory.
[0] https://golem.ph.utexas.edu/category/2008/12/the_microcosm_p...
Telephysangelists should also start questioning the 5% of what they do understand. All we hear about is DM/DE as if the underlying assumptions that lead us to believe they exist must, at any cost, be true. It reeks of more lost decades of scientific discovery to me, but then again I'm just a bystander.
The blue is dark matter. The pink is normal matter.
It's thought that the two clumps of blue+pink there passed through each other. But the blues went right through each other, undisturbed, while the normal pink stuff formed a shockwave.
>most of the mass in the cluster pair is in the form of two regions of dark matter, which bypassed the gas regions during the collision. This accords with predictions of dark matter as only weakly interacting, other than via the gravitational force.