What is an object that appears not to move and is used to judge motion?

An object that appears not to move and is used to judge motion?? what is the answer.. i need it in about 10 mins for mii science hw..??? plzzWhat is an object that appears not to move and is used to judge motion?
Is this a trick question ? there isn't anything in the universe that we know of that 'doesn't move' (or that we can prove that it doesn't move -- so if we can't prove it, we can't know if it is moving or not).





If the entire universe was moving sideways at 20 mph (or faster), everything would look the same to us as as if it wasn't moving. This is one of the things that Einstein talked about in his theory of relativity (he showed that you can't use light, and it's speed, to determine if something is moving), and Galileo talked about this in the 1600's (his example: being inside a ship sailing so smoothly that you can't tell if it is moving or not -- except if you have a window/porthole to look out of).





So we judge motion in relation to other objects. So a cop uses his radar gun to measure a car's speed in relation to (relative to) the street. The street doesn't appear to be moving, so we just talk about how fast the car is moving. In reality, the street IS moving -- it's part of the Earth, which is orbiting the sun, moving rapidly that way, and is also spinning, moving in a second way.





So all motion is judged in relation to something else. What you pick depends on what seems to make sense for the measurement you are making. The object you compare to (usually the Earth, like the cop does when he gives you a speeding ticket) is called the 'reference point';.





hope this helps.