# How many colors are there?
**URL:** https://boards.straightdope.com/t/how-many-colors-are-there/204967
**Category:** Factual Questions
**Created:** [October 1, 2003, 7:11pm UTC](https://boards.straightdope.com/t/how-many-colors-are-there/204967 "2003-10-01T19:11:45Z")
**Posts on this page:** 2
**Page:** 3
### Author:  [@swansont](https://boards.straightdope.com/u/swansont)
#### Post date: [October 5, 2003, 11:27am UTC](https://boards.straightdope.com/t/how-many-colors-are-there/204967/41 "2003-10-05T11:27:05Z")
> [@](#):
>
> \*Originally posted by MC Master of Ceremonies \*
> \*\*Surely if the wavelength of a phton is dependent on the size of the universe that implies an alarming degree of non-locality, what about a photon between two barriers? Also given that the size of the universe from apparent observations is infinite a photon could still have any wavelength.
> \*\*
The wavlengths available are dependent, not the wavelength itself. A photon between barriers has fewer modes available, not more - this effect is seen in cavity QED experiments.
The size of the universe is not infinite, AFAIK - the Hubble constant and WMAP, etc. point to a finite age and extent. If you have a references that say otherwise, please provide a link.
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### Author:  [@MC\_Master\_of\_Ceremonies](https://boards.straightdope.com/u/MC_Master_of_Ceremonies)
#### Post date: [October 5, 2003, 11:47am UTC](https://boards.straightdope.com/t/how-many-colors-are-there/204967/42 "2003-10-05T11:47:31Z")
Yes the phton between two barriers has fewer modes but surely those modes are independent of the modes avaidable to a unbounded photon meaning that they may be in the range of ‘forbidden’ modes. Though I take back what I said about non-locality as thinking on it more the expansion is non-local.
The universe appears to be flat from observation, as you should know (I see you work at the USNO) a flat universe in most standard cosmological models is infinite in extent (though there is a 3-torus shape that produces a flat finite universe, but an infinite universe is seen as more likely).
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