I know an object can be stationary relative to another, but is there anything absolutely stationary in the universe? Or is space itself expanding and thus nothing is stationary?
In: Physics
No. Gravity has infinite range, so no matter where you are in the universe there will always be something that is moving you and being moved by you
There’s no absolute reference frame in space, the concept of stationary only makes sense in relation to another object
* Gravity has infinite range and thus an object will always have some force acting upon it, which will move it even if imperceptably
* Unless an object is at absolute zero, which is impossible, heat will make its molecules shift and wiggle, even if very slightly
* “Stationary” isn’t even a really well-defined term here
All motion is relative motion.
There is no such thing as “standing still” from an absolute perspective, because every perspective has a different reference frame.
nothing is technically stationary anywhere if you remove the qualification of “in relation to ___” because you can always expand the frame of reference to a point where a “stationary” object is no longer stationary.
eg. A plane on a tarmac is stationary. but the earth is moving…….
a satellite in geosynchronous orbit can be stationary, but again the earth is moving……
you could never be absolutely stationary because everything is moving at different rates so you will always be moving in relation to something on an infinite scale of relativity.
No, because velocity is determined based on reference frame. You might be practically still in a chair you’re sitting in, despite invisibly small movements and vibrations of molecules, etc. You’re velocity is essentially 0 m/s relative to the chair. But relative to the sun, you’re still moving around 30,000 m/s. And relative to the center of the galaxy, based on a quick google search and a quick calculation, you’re moving at about 230,000 m/s. It’s all about reference frame.
Unless you somehow get all particles in existence to be still relative to each other, there is no such thing as being absolutely stationary.
There is no such thing as absolutely stationary, because all movement is relative to some other object/frame of reference.
If you think about it, how would you measure/prove that something was absolutely stationary? Stationary compared to what?
Let’s say you are out in deep space. You are in a space suit and are absolutely stationary. You aren’t moving at all. Now, out of nowhere comes this other dude in a space suit. He goes flying by you really fast. That idiot almost slams into you! Why doesn’t he watch where he’s going?
The thing is, from his perspective, *he* was just floating there perfectly stationary. He thinks *you’re* the idiot who was flying out of control and wasn’t watching where he was going.
There’s no universal point of reference to decide who is stationary and who is not. Everything is moving around compared to some other thing.
There might be. But we haven’t found it yet. One of the properties of Space-time is that everything is always in motion. Mass is always falling into a larger gravity well. Even Space-time itself seems to be moving (expansion).
It could, but there would be no way to tell. The frame of reference is infinite, so trying to take a measurement will never result in an absolute, concrete quantification.
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