# Did space exist before mass?

1. Feb 10, 2012

### Karl Coryat

I read that before the beginning of the quark epoch at t = 10–12 sec., particles don't have any mass. Does that mean that all particles before t = 10–12 sec travel at c?

In other words, can a particle without mass travel at less than c? The Wikipedia article on massless particles says, "The behavior of massless particles is understood by virtue of special relativity. For example, these particles must always move at the speed of light." I would be happy to adjust the Wikipedia article if this statement is inaccurate.

If such particles do always move at c, and all particles at this epoch are massless, how can it be said that space exists during this epoch? What non-c "observer" measures spatial separation between objects (or temporal duration for that matter)? It seems that mass/sub-c travel is required for the concept of "reference frame" to have any ontology or meaning.

Any help with this conundrum would be appreciated -- thank you.

2. Feb 10, 2012

### James Leighe

Massless particles will travel at c.

Just because you can't construct a rest frame for one of the particles does not mean that you can't construct any frame at all.

3. Feb 10, 2012

### Jarfi

I don't think people can answer that, it's like saying, did enegry exist before the big bang, and well, mass is the result of space bending isn't it, either we had an epty space with a dot of singularity exploding in it, or we had nothing and both were created at the same time,

But we did not have mass before space, we may have had energy, but not gravity.

Or we had mass, but it had no space to work on, It's an interesting question.

4. Feb 10, 2012

### Karl Coryat

Thank you for the replies. The question does seem a little metaphysical. But it isn't quite like asking what came before the big bang, or which came first, mass or curvature. We do know that the universe evolves from t = 0 to t = 10–12, and in that time, inflation generates a tremendous amount of space. But with respect to what, in a universe with no massive particles....

Perhaps the best way to put it is, the description of the early universe refers to what would be observed if a massive particle could have existed at the time. Is that a reasonable position to take?

5. Feb 10, 2012

### James Leighe

I don't understand, what's the question again?

I'm not sure about if particles like quarks had mass or not, they probably did.
I don't think the higgs field would have been any different nor the 'couplings' to it of the various particles.

But I could be wrong there, and we don't even really have any proven ideas about the origin of mass.

6. Feb 10, 2012

### Drakkith

Staff Emeritus

7. Feb 10, 2012

### DaveC426913

There was no matter at all in the early stages of the universe. Matter did not condense out of energy until much later, when the universe had cooled significantly.

There was mass, but it was not from matter.

8. Feb 11, 2012

### Karl Coryat

From here: http://www.fqxi.org/community/forum/topic/990

"For example, until the so-called “quark epoch” between 10-12 and 10-6 seconds after the Big Bang, particles don’t have any mass. By acquiring mass, the universe adds a little bit of variety to the mix." He's talking about the entropy of the universe before and after the Higgs mechanism kicks in. Is the statement inaccurate?