# Is the Universal expansion caused by ''heat''?

Discussion in 'Physics & Math' started by Dylan, Oct 8, 2017.

1. ### DylanBannedBanned

Messages:
58
The Universe is expanding. When a gaseous cloud is heated , it expands. Is universal expansion just simple a consequence of thermodynamics?

3. ### mathmanValued Senior Member

Messages:
1,973
The universe is cooling down as it expands.

5. ### DylanBannedBanned

Messages:
58
I did not ask if the Universe was cooling down as it expands, I asked if heat was the cause of the expansion?

Messages:
11,713
No.

Messages:
58

9. ### originHeading towards oblivionValued Senior Member

Messages:
11,713
I can tell you it's not heat. The universe is cooling. Heat causes gas to expand not space. You cannot heat a vacuum to make space expand.

Jordan.S likes this.

Messages:
3,252

11. ### timojinValued Senior Member

Messages:
3,252
I am not sure of the question , but does the universe have boundary ? If there is no boundary as a reaction take place the volume should decrease and heat will be released , the produced heat will produce work on the surrounding bodies ( in a motion form ). If there is a gravitation force , the produced heat counteract the gravitation force.

12. ### exchemistValued Senior Member

Messages:
11,635
I don't think this is really resolved, though there is a hypothesis described in this Wiki article: https://en.wikipedia.org/wiki/Metric_expansion_of_space

I quote below the relevant section:-

"The modern explanation for the metric expansion of space was proposed by physicist Alan Guth in 1979, while investigating the problem of why no magnetic monopoles are seen today. Guth found in his investigation that if the universe contained a field that has a positive-energy false vacuum state, then according to general relativity it would generate an exponential expansion of space. It was very quickly realized that such an expansion would resolve many other long-standing problems. These problems arise from the observation that to look like it does today. The Universe would have to have started from very finely tuned, or "special" initial conditions at the Big Bang. Inflation theory largely resolves these problems as well, thus making a universe like ours much more likely in the context of Big Bang theory.

No field has yet discovered what is responsible for the cosmic inflation. However such a field, if found in the future, would be scalar. The first similar scalar fieldproven to exist was only discovered in 2012 - 2013 and is still being researched. So it is not seen as problematic that a field responsible for cosmic inflation and the metric expansion of space has not yet been discovered."

13. ### Jordan.SRegistered Member

Messages:
24
In tend to think that heat causes matter to expand however, this does not necessarily mean that any expansion is caused by heat. Electromagnetic repulsive forces may in some circumstances cause some thing to expand.

14. ### DylanBannedBanned

Messages:
58
Thank you kind sir for your reply. I am quite confused to what you mean by this: You cannot heat a vacuum to make space expand.

15. ### DylanBannedBanned

Messages:
58
Thank you kind sir for the link you provided. Could you please explain this part of the link:This is a completely different kind of expansion than expansions and explosions we see in daily life.

I do not understand kind sir , how can there be different interpretation of the word expansion.

16. ### exchemistValued Senior Member

Messages:
11,635
Expansion of the universe is expansion of the metric itself. There is a description of it here: http://www.universe-galaxies-stars.com/Metric_expansion_of_space.html

You need some understanding of general relativity (which I do not have) to grasp this properly but it is not the same as a normal expansion which involves the object's surface moving in space so that it takes up more space.

It follows that analogies with expanding gases etc do not work.

17. ### DylanBannedBanned

Messages:
58
Thank you kind sir for your link. In the link it says :A metric defines how a distance can be measured between two nearby points in space

Yourself explains:Expansion of the universe is expansion of the metric itself.

Are you and the link saying that the expansion is just an increase in measurement of distance between points? A measurement expansion?

18. ### originHeading towards oblivionValued Senior Member

Messages:
11,713
Are you a sock puppet or just a new anti-science poster? I am going to go out on a limb here (

) and predict that you will just exhibit more and more trolling behavior as time goes on. You have no intention of actually discussing this.

I hope I am proven wrong, but I don't think so....

19. ### exchemistValued Senior Member

Messages:
11,635
Something of the sort. But, as I say, I am not expert on this, as we chemists did not study GR at university. I think you will have to rely on your reading and possibly what other people here may be able to tell you.

20. ### exchemistValued Senior Member

Messages:
11,635
The meaning of this is fairly obvious.

Expansion of matter due to heating is a result of the increasing thermal kinetic energy of its constituent particles (molecules, atoms and so on). Without matter, you have nothing to which heat (i.e. thermal kinetic energy) can be transferred.

21. ### DylanBannedBanned

Messages:
58
Thank you kind sir for the clarification, I now understand that you are saying that space can not expand by heat because it is not made of molecules,atoms.

22. ### DylanBannedBanned

Messages:
58
I am sorry kind sir, I do not understand the term sock puppet, I am new to the internet and science forums. What is a sock puppet?

23. ### The GodValued Senior Member

Messages:
3,546
Generally speaking I do not see eye to eye with "kind sir" Origin, but whoever you are, I think Origin this time is spot on. You are definitely trolling. But I enjoyed rather had a hearty laugh on your use of word "kind sir" in every post. It's bloody so obvious that your intentions are to loiter around. But not very long.