# Movement of mass

1. Oct 27, 2013

### wetwonder

Am I right in thinking that any bit of mass, eg. me, or my spoon, or a planet, can never not be moving? And also as the matter inside me changes to something else, re-assembles later, etc, for-"ever."

So respective to that, space time is constantly distorting in it's path? From the beginning of the universe, there has been a constant distortion caused by all mass - and will be ongoing?

(Presume, moving relative to some other mass.)

Last edited: Oct 27, 2013
2. Oct 27, 2013

### Simon Bridge

No.
You can always find a reference frame in which some object is stationary.

Matter is energy and energy cannot be created or destroyed - only change form.
That what you are thinking of.

If you mean the curvature of space-time is related to the energy density?

3. Oct 27, 2013

### wetwonder

Is there an example of matter that we can observe that is not making a continual/constant change of position in space time?

I guess in other words everything has a velocity, and is making a wake from distortion of space time?

Last edited: Oct 27, 2013
4. Oct 27, 2013

### Staff: Mentor

There's no such thing as a "position" in space-time, only in space, and there motion can only be defined relative to something else. I may say that I am rest on the surface of the earth while a train moves past me at 100 km/hr, but someone on the train will, with equal justification, say that he and the train are at rest while I and the ground are moving backwards at 100 km/hr.

There is no such thing as "leaving a wake" in space-time.

5. Oct 27, 2013

### wetwonder

hmm-

6. Oct 27, 2013

### wetwonder

I understand. May I restate that last comment? Is there an example of an object that we can observe that is not continually/constantly warping space time relative to another object?

7. Oct 27, 2013

### Simon Bridge

"continually" and "constantly" kinda suggest a process ... the curving of space-time due to a an energy distribution is not a process so much as something that just is there.

Perhaps if you gave us some clue about the context against which you are asking these questions?
What is the idea you are wrestling with?