If speed is a function of distance/time, in reference to the universe, how fast are we really going?

Question

In other words, distance is a misnomer in relation to the universe (infinite space). We can measure distance from ourselves using ourselves as a reference point, but what is our cumulative speed (earth's rpm, earth's orbit around the sun, our solar system's orbit around the milky way, the universe expanding away from itself, etc.) if we have no reference point outside of our system already in motion? Does the special (or general) theory of relativity have an answer?

Or am I totally missing something?

Answer 1

That is a big question in physics. Just what IS the absolute frame of reference? What IS the absolute spacetime? You're stating all the different speeds based upon different reference points is a nice, simplistic summation of Relativity. It's all relative to the oberserver and the observer's frame of reference. Even different observers measuring something from different frames of reference can both be completely correct with their different results.

If you can find it, try reading Brian Greene's newer book: The Fabric of the Cosmos. You'll defintely like it. It's a good starter book. And, why am I seemingly ducking the answer to your question by saying go get a book? Cause it'll take a book to thoroughly answer your question. And, I keep getting complaints my answers get too involved.

Answer 2

Velocity has meaning only when there are two or more things involved. Velocity is part of the relationship between two objects. It has no meaning when you confine your thinking to one object only. That's why velocity is "relative." When you ask "How fast are we REALLY going?" you presume that velocity has meaning for one object alone, which is not true.

Now there is one more idea to keep in mind. Velocities total in vector sum only approximately, and only when none of the velocities being added is a significant fraction of the speed of light. To be more precise with your calculations, you must understand that ENERGY is what adds exactly. You must *derive* the consequences for velocity after you've satisfied the law of conservation of energy for whatever your physical system is doing.

Answer 3

Relativity does indeed deal with this question. You aren't simply moving, you are moving RELATIVE to another object. A person on another planet sees you moving and himself standing still. You see HIM moving and YOU are standing still. Relativey theory is always referencing the OBSERVER. Observers in different places or traveling in different directions see things differently.

Answer 4

You are correct, If our star were the only star in the entire universe but it were in the same place it is now and going the same "speed" we would probably have absolutely no way of knowing this speed.

Answer 5

Velocity can only be measured in reference to other objects. Light is an exception to this rule.

Answer 6

Estimates vary. I've heard of figures like 400,000 miles per hour in ALL directions at one (rotation and direct travel).

Answer 7

to tell u the true i really don'y know