Could we measure earths speed relative to the center of the universe?


Since i heard really often that light always travels at the same speed. Even if i travel at half the speed of light, and shine a light to the Front, the light would travel at the speed of light not 1.5 times the speed of light.

With this method we could build 3 long tubes (one for each axis, x;y;z) and then measure how long the light take inside the tubes, with this data we could calculate the speed of this facility in relation to the center of the universe. Is this possible, what would be the challenges?

In: Physics

No, as there is no center of the universe. So we have to measure it relative to some object(s) instead.

I think you may enjoy the book We Have No Idea. If you study this stuff it may be too simple, but as someone with just an interest in space, it’s freaking awesome.

There is no center of the universe. Do you mean galaxy?

There is no such thing as the center of the universe. It’s not an object or a volume like you normally thing of. Take the surface of a sphere for example. The surface of a sphere has no center. Note that there’s no evidence that the universe is any particular shape. In fact, we think it’s probably infinite.

Light moves at the same speed for all observers.

So if you were traveling at 50mph on a train and threw a ball at 50mph you would measure the balls speed as 50mph relative to you. If I were standing beside the train I would measure the ball as moving at 100mph relative to me.

But this doesn’t work for light. If you were moving at 0.5c (150k km/s) and “throw” photons at c (300k km/s), where is the photon 1 second later? You would measure the photon being 300k km away from you. But as the “static” observer I would measure the photon being 300k km away from me and only 150k km away from you (because you also moved 150k km).

So which is it? Did the photon move 150k km away from you in one second or 300k km in one second?

Yes! Both are true! Because you and I experience time differently. What I measure as 1 second you measure as only 0.5 seconds.

The faster you move the slower time passes *for you*.

There is no one set, fixed, universal, or objective frame of reference for measuring time, distance, or speed. We can only measure it in relation to us or another defined point. Consequently, from whatever frame of reference you choose, *that* point will calculate as the center of the universe.