# Matter at rest

1. Nov 28, 2008

### Ranger Mike

in the universe, as far as i can determine, every thing is moving..
energy moves, planets move, is there any matter that does not move?

AKA matter at rest...not moving thru space..
stationary

not talking about energy..just Matter..(AKA...Matter is also know as Mass being associated with gravitational fields)

am new guy and thanks for any input
ranger mike

Last edited: Nov 28, 2008
2. Nov 28, 2008

### pallidin

Unfortunately, there is no "all-encompassing" permanent stationary reference point within our universe from which to ascertain absolute non-movement of something else.

3. Nov 29, 2008

### Ranger Mike

thank you for taking the time to explain. from what you said, may i assume that everything is moving in the universe?
there is no single point of rest, stationary non movement?
or is it that we can not observe it since we are moving?

4. Nov 29, 2008

### Danger

The problem comes from the fact that movement has to be measured relative to something else. As Palladin stated, there is no 'starting point'.
Take the example of launching two identical space probes simultaneously in the same direction. Relative to each other, neither is moving at all. From Earth, both are traveling at maybe 30,000mph. Someone watching from Mercury would measure a totally different speed for both.

5. Nov 29, 2008

### Staff: Mentor

Another way of saying it is that you are free to point to anything you like and declare "By the executive order of Ranger Mike this object is declared to be at rest". I could not make any physics experiment to prove you wrong.

Of course if I then declared "No, by the executive order of DaleSpam this other object is declared to be at rest" then you would be unable to make any physics experiment to prove me wrong.

6. Nov 29, 2008

### Ranger Mike

ok gotcha! Can some one confirm the following: Matter is Mass x Volume, and Energy has Mass as well. Both can be transformed into the other..i.e. Mass can become Energy and Energy can become Mass
(gamma ray stopped will become matter and anti matter if only for a split second) and both Matter and Energy have similar laws of Conservation.

7. Nov 29, 2008

### gendou2

8. Nov 29, 2008

### Ranger Mike

Ok that pretty much confirms things about Matter and Energy.

In General Relativity ..is there any thing else in the universe besides Matter, Energy (gravity is a subset of this) and Space? Space Time not included in this discussion as of yet...

9. Nov 29, 2008

### gendou2

General Relativity is a theory of gravity. It is not a theory of the other forces of nature, namely Electromagnetism, and the Strong and Weak nuclear forces.

10. Nov 29, 2008

### LURCH

And one of the tenets of general relativity is that gravity is not an energy field, but rather a condition of space (or space-time, but were not getting into that yet).

11. Nov 29, 2008

### Nick89

I don't think you can think about general relativity without 'getting into' the theories of space-time. I believe in GR, space-time is curved, not just space.

12. Nov 29, 2008

### Ranger Mike

Thank you guys for the help understanding this stuff. I got the Mass thing down pretty good and energy too.

But before i can move on to Space Time ( and the curent thinking that Gravity is a measure (mass of the coupling between Space -time and Matter) i gotta understand Space.

Does Empty Space have Mass?
Does Empty Space have Energy?

from a previous post i learned that energy is everywhere. Even Empty Space. zero point energy. correct?

Last edited: Nov 29, 2008
13. Nov 29, 2008

### Burningmace

To get truly empty space there must be no particles at all - no electrons, no neutrons, no photons, no leptons, no quarks, nothing at all. Each particle has energy, therefore it has mass. However, you cannot truly have empty space with no energy. I'm not hugely clued on this, but it is my understanding that due to the (absolutely minuscule) forces between particles outside of the empty area of space, there is an energy. If there is energy, there is mass. Therefore you can never have empty space with no mass or no energy - there is always something there.

Try reading up on Vacuum Energy and Zero Point Energy at Wikipedia.

14. Nov 29, 2008

### Ranger Mike

thanks for the input
i found the answer
great web site

Last edited: Nov 30, 2008