In school, I was taught that the speed of light is constant, in the sense that if you shoot a laser off of a train going 200 km/h, it still just goes at a speed of c=299,792,458 m/s, not at c + 200 km/h.

What confuses me about this, is that we’re constantly on a metaphorical train:
The Earth is spinning and going around the sun. The solar system is going around the Milky Way. And the Milky Way is flying through the universe, too.

Let’s call the sum of those speeds v_train.

So, presumably if you shoot a laser into the direction that we’re traveling, it would arrive at the destination as if it was going at 299,792,458 m/s - v_train.
The light is traveling at a fixed speed of c, but its target moves away at a speed of v_train.

This seems like it would have absolutely wild implications.

Do I misunderstand something? Or is v_train so small compared to c that we generally ignore it?

  • MystikIncarnateEnglish
    1·
    1 year ago

    Yep, nobody has come up with a way to do it, very very smart physisicts have not solved the problem, there’s no hope you or I could.

    We can speculate all day about it, but it won’t really go further than that. So in lieu of an actual solid scientific answer, we just have to assume that’s it’s too small of a difference to matter in our current level of technology.

    Here’s what bakes my noodle though… The speed of light, c, is a universal constant of speed. Well, speed is relative. It is always relative, but the speed of light being a constant and upper limit of speed, I have to ask, relative to what? If light is moving at this constant speed, what, compared to light, is stationary? The universe is a swirling mass of matter in various shapes, sizes and forms… Everything is constantly in motion, so what static/stationary thing are we basing that speed off of? Space itself is a vacuum, so there’s no real way to tell what the relative “not moving” speed is, and everything in the universe is moving relative to anything and everything else, at varying rates… Is it the galactic core or the middle of the universe? How do we know that the observable universe isn’t moving at incredible speeds?

    But I don’t want to derail the conversation too much. I know that most of this either delves into deep quantum physics, or is simply outside the realm of the current human understanding of everything, and again, we’re left to only speculate about it, which doesn’t actually get us anywhere.

    IDK, it’s fascinating to think about but ultimately, not beneficial to spend significant time on.