Help me understand something… If the universe is infinite and the big bang happened everywhere at the same time, then there are objects out there moving away from our galaxy at speeds that are infintely fast. I don’t want to say it, but according to where we stand, if we could measure the speed of these objects that are infintely far away, it would seem that they are moving “faster than the speed of light.” Right? This is because every point is the center of the universe; if an object is farther away, it is moving away from us faster than an object that is closer. If an object is infinitely far away, the object is moving exponentially faster away from us than a closer object.
Assuming that I got that much right – crosses fingers– could we ever reach one of those objects that is moving inifinitely fast away from us, even if we learned how to travel at or near the speed of light?
I guess this is what I am having trouble grasping: If you were in that vehicle travelling at the speed of light, how can your speed ever stop being relative to where you started? How would you ever start to gain on an object that was seemingly moving “faster than the speed of light” according to your initial starting point?
Sorry if I have given you a headache. Please be patient.
No, there are no such FTL objects that we know of (there may be FTL subatomic particles). The Big Bang did not explode from everywhere at once, but expanded from a single point to erupt into what we now know as the universe. At that “time” such as it was, it may have possible to travel faster than light. However, this is speculative, since before the universe properly coalesced physical law was a bit iffy. Regardless, nothing is traveling FTL now.
Now, if you actually sped up faster than light, you would get going faster and faster. However, from the POV of the rest of creation, you would actually start to get slower past that point. Time would slow down for you, such that you would never actually get to FTL speeds. Additionally, getting there would require infinite energy. This would effectively give you infinite mass at the point where you actually hit lgihtspeed, causing the universe to explode/collapse. Which might start a new Big Bang. We’re not sure.
Now, according to some theories, a similar effect happens if you go straight at a Black Hole. You enter the Event Horizon, and are sucked straight into the singularity. What happens then is that you go slower and slower - but you’ll never get sucked in. Time slows down for you, and in afct you can never actually reach the center. At the time that you do, you’ll actually be ejected back out into space through a “White Hole”. But we haven’t tested this theory.
Short answer: yes. However, you will never be able to measure such objects if they exist. They are, for all intents and purposes, outside the observable universe.
No. These objects are outside of our universe and will never be inside of it. To put it a different way: in a universe with a constant expansion (which our universe is not: but that’s another story: for our purposes you can assume it basically is) objects that are outside of the so-called horizon will never be inside the universe.
It is relative to where you started. It is also relative to any other point you care to name.
And there you have it: you wouldn’t be able to do it. You would never get there (and I do mean never).
Hope this helps.
You contradict yourself. Both scenarios you outline are equivalent.
Some of this is correct and some of this is incorrect. Increasing your velocity does increase relativistic mass, but that’s a bit confusing in the terminology. The only reason the relativistic mass concept was invented was because of the infinite energy problem you posit. The thinking was that you are adding energy to an object that doesn’t change its kinetic energy so it must be changing its mass energy. However, there are some sticking point with this treatment that aren’t well-dealt with. For example, the relativistic mass energy is not invariant with respect to reference frames making mass a problematic concept. That’s why the full relativistic treatment of E^2=m^2C^4+p^2c^2 was developed in order to get a mass that was invariant: what we call “restmass”.
Now, as we increase an object with a nonzero restmass’s speed to the speed of light it will require an infinite amount of energy to do it. As there is not an infinite amount of energy in the universe, such a thing is impossible.
