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Possibilities for a 5th force? 
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#1
Jul1514, 09:30 AM

P: 111

It is quite accepted that at sufficiently high energies 3 of the known 4 forces merge into 1 fundamental force, and it is expected by many that at even higher energies gravity should also merge with them into a single primordial force. We find ourselves in an energy period of the universe where the primordial superforce has split into 4 by different symmetry breaks.
But taking the other way, towards the future and even lower energies than current, has anybody ever speculated that a new symmetry breaking could occur creating a lower energy 5th force? Why should the splitting stop at 4? 


#2
Jul1514, 11:39 AM

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PF Gold
P: 1,908

All experimental tests of "fifth force" have failed, but cosmologists persist!
See https://en.wikipedia.org/wiki/Fifth_force and http://www.sciencedaily.com/releases...0221192736.htm This goes to show that once an idea appears on the horizon, it never disappears! 


#3
Jul1514, 12:16 PM

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#4
Jul1514, 03:20 PM

Sci Advisor
P: 6,035

Possibilities for a 5th force?
I don't know if anyone is specifically looking for a fifth force. However many lab experiments take place at temperatures close to absolute zero, so I suspect there is no such force.



#5
Jul1514, 04:30 PM

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PF Gold
P: 9,360

You could make a case for dark energy as a fifth force. Scientists are fairly convinced it exists, but, have little clue what it is, how it interacts, or its mediating particle. Not that we know all that much more about gravity. The graviton is the hypothetical mediating particle for gravity, but, has never been experimentally detected.



#6
Jul1514, 05:24 PM

Engineering
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P: 6,937

Not my specialist subject, but it seems strange that string theorists can only postulate of one more force. Can't they come up with an reason why there should be at least 37?



#7
Jul1714, 10:37 PM

P: 3

Hello there,
there is a nice book speaking of the tests conducted on the hypothesis of a fifth force. http://www.amazon.com/RiseFallFift.../dp/1563961199 There is research going on on some new experiments (At JLab and GSI), where they try to detect some new gauge bosons A' (popularly named dark photons) which could be mediators of a new fifth force acting on dark matter. (if i get it correctly) http://www.nature.com/news/physicist...forces1.10386 


#8
Jul1814, 01:55 AM

P: 111

Thanks!



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