All right, this is mostly based on theory, but I figure GD may be the more appropriae place for this. First off, keep in mind that I’m assuming a couple things here: 1. That the universe was created as the Big Bang Theory describes, thus the center of the Universe is a single identifiable point, 2. You have in your possession a handy-dandy spaceship that 3. has sensors that are capable of detecting photons with 100% accuracy.
I don’t want no quibbles over “well, you really couldn’t do that, so the point is moot”.
ANYway… so you’re out in the middle of space, doing what space travelers do best… trying to do stuff that’s difficult to do. You want to see if you can stop all velocity of your vessel in any direction. By conventional means, you would pick the closest big object and make sure you don’t move in relation to THAT (a planet, star, asteroid, Jennifer Lopez’s butt, etc.). However, by this method, you would still be moving (the planet orbits a star, the star moves with the galaxy, Jennifer Lopez keeps making movies, etc.). So, conventionally, you can’t stop “moving” (having a velocity).
HOWEVER… (this is where my meager understanding of the Theory of Relativity comes partially into play, feel free to correct me), the ToR says that light coming from a source moving away from you would appear to be moving slower (dimmer), while light moving towards you would appear to be moving faster (brighter)… yes? No? Well, it’s not entirely important to what I’m getting at…
Now, say that you detect the photons being emitted by two stars, both on the same line (or the closest approximation you can make) from your starship, and all three are directly in line with the Center of the Universe (CotU), assuming there is one and assuming we’ve found it by now.
Wouldn’t you be able to compute the photon speeds from these two stars to figure out how to bring your vessel to a total and complete stop, ZERO velocity in ANY direction? Even if my stuff about the ToR is way off, wouldn’t this be a plausible means to pull off something utterly useless (although I’m sure some scientist can find a way to make “Zero Velocity” sound interesting)?