[OT] How many dimensions? (WAS: Power over radio)

[Shachar Shemesh]

Dotan Cohen wrote:
>
> Oleg, I understood that the universe has 11 or so dimensions, and that
> 5 or six can even be measured. But the wikipedia article that you link
> to claims only 3+1. I have googled a bit but found only very technical
> explanations, or baby facts with no explanations. Can you sum it up
> for someone who is familiar with relativity, but is not a physicist?
> Thanks.
>
>
>   
I'll do my best as another non-physicist, and then Oleg (or anyone else) 
can correct me where I'm wrong.

In an attempt to create a grand unified theory(tm) of everything (and 
rejecting, with no explanation, the answer "42"), some physicists have 
tried the "big hammer"(tm) approach - i.e. - hammer on the equations 
until they fit. This method is not to be put down, as it allowed Lorentz 
to phrase his Lorentz transformation even before Einstein came around 
and provided a relatively simple (excuse my pun) explanation for the "why".

In particular, the modern hammerists came up with "strings theory". It 
is an extrapolation of existing theories, designed to encapsulate all 
known to be somewhat true theories about the universe (in particular, 
general relativity on the one hand, and quantum mechanics on the other). 
Strings theory does, indeed, claim that the universe has 12 dimensions.

Here's the catch. Strings theory is so generic, that it fails to supply 
one of the basic requirements of any scientific theory. It fails to 
provide predictability. Any scientific theory must come with an 
experiment that is possible to perform (at least theoretically), with 
certain outcomes being agreed to mean that the theory is disproved. If a 
theory cannot supply such an experiment, it means that any possible 
outcome of any possible experiment is okay with that theory, and this 
means it lacks any ability to actually predict the outcome of yet 
unperformed experiments. Such a theory may be fine for philosophers, but 
is useless to scientists, and in particular, to physicists.

And yet, it seems that strings theory is very far from useless. Strings 
theory has garnered support, and more importantly, research grants, and 
have occupied the time of our bests physicists around the world, with 
nothing concrete to show for it but the money well spent. It is trendy, 
and has been for quite some time now, but, at least as far as I'm 
concerned (and unless I am totally misunderstanding the situation, which 
is possible), it is not physics. People like it because of its 
potential, but this potential, after over a decade of research, has 
failed to materialize into something you can try and disprove.

Shachar

-- 
Shachar Shemesh
Lingnu Open Source Consulting Ltd.
http://www.lingnu.com

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