B A world made of continuous matter

[black hole 123]

This is probably stupid question but is it logically possible for a universe to exist where matter is continuous and not atomic? How would such matter be stopped from collapsing to a point?

 

[phinds]

No, it doesn't make sense, and that's even aside from the fact that you have not defined what you mean by "continuous". I'm taking it to have the normal meaning.

 

[Dale]

I disagree, or at least I am not sure enough to definitely claim that it is logically impossible. Classical mechanics seems to be logically self consistent, so my initial guess is that such a universe would be logically possible.

Clearly we do not live in such a universe, but in many cases it can be treated as such.

 

[A.T.]

I disagree, or at least I am not sure enough to definitely claim that it is logically impossible. Classical mechanics seems to be logically self consistent, so my initial guess is that such a universe would be logically possible.

I reminds me of a brain teaser from Epstein's "Thinking Physics":

If the universe was filled with a liquid, how would two nearby bubbles in it (of lower mass density than the liquid) behave?
a) Move towards each other
b) Move away from each other
c) Not move at all

 

[phinds]

I disagree, or at least I am not sure enough to definitely claim that it is logically impossible. Classical mechanics seems to be logically self consistent, so my initial guess is that such a universe would be logically possible.

Clearly we do not live in such a universe, but in many cases it can be treated as such.

I take "continuous" to mean "no space anywhere inside". I guess maybe a neutron star does that, or at least close?

 

[Dale]

I take "continuous" to mean "no space anywhere inside". I guess maybe a neutron star does that, or at least close?

I think a continuous world would be one where the continuum approximation holds exactly, so there would be no atoms or fundamental particles of any kind, but only continuous blobs of matter that could be infinitely divided.

 

[phinds]

I think a continuous world would be one where the continuum approximation holds exactly, so there would be no atoms or fundamental particles of any kind, but only continuous blobs of matter that could be infinitely divided.

That's actually what I thought of as well, but I don't get how it's possible. If there are no particles, how does stuff come into being?

 

[A.T.]

If there are no particles, how does stuff come into being?

Classical Mechanics isn't concerned with that. It just predicts what will happen given some initial state. And it often makes the continuum approximation, as Dale said.

 

[phinds]

Classical Mechanics isn't concerned with that. It just predicts what will happen given some initial state. And it often makes the continuum approximation, as Dale said.

OK, thanks for that.

 

[Drakkith]

This is probably stupid question but is it logically possible for a universe to exist where matter is continuous and not atomic? How would such matter be stopped from collapsing to a point?

We can't answer that since that isn't the case in our universe.

I think the last few posts are a good way to end this thread. Thread locked.