1cc of Photons?

[YT2095]

this may seem like a strange question, but how many photons can occupy the space of 1 cubic centimeter?

since a photon is a wave and/or particle, then a wave takes place in space and must therefore occupy some of it, and a particle has volume.

so how many photons can you pack into 1 cc?

 

how big/small are they?

[Klaynos]

They can over lap as well

 

So for an answer to this we'd have to convert all the mass energy in the universe into photons, count them, and that would be the answer

 

There's no physical limit.

[YT2095]

so what is the actual size of a photon then?

[Klaynos]

so what is the actual size of a photon then?

 

It doesn't have what can classically be thought of as a size...

 

Some people like to think of the wavelength as it's size...

[ajb]

Photons are usually considered to be point-like.

 

I don't know if you can give them an "effective" size or something via vacuum polarisation or something.

 

Usually "size" is more to do with scattering.

[Royston]

There's some discussion on the same question here...

 

http://www.scienceforums.net/forum/showthread.php?t=29550

 

Just to expand on Klaynos's first post, photons are bosons (integer spin), and are therefore not constrained by the Pauli exclusion principle i.e they can occupy the same quantum states, as opposed to fermions (e.g electrons) which have spin +1/2, -1/2.

 

I think the confusion arises, because photons are considered discrete units, but this is really only discrete units of energy, and shouldn't be confused with a discrete unit of size e.g length or volume.

[YT2095]

I think the confusion arises, because photons are considered discrete units, but this is really only discrete units of energy, and shouldn't be confused with a discrete unit of size e.g length or volume.

 

so it`s like asking how many volts will fit into a 1cm cube then?

[Royston]

so it`s like asking how many volts will fit into a 1cm cube then?

 

Pretty much, the potential difference across an area 1cm^3 is only limited by the conductor, so in principle, as much voltage as you want (ideal situation of course).