That is true on earth, but not in space/void, where there is no resistance at all.

How does this gain of mass works?
If a big ball of gold is sent orbiting around earth, will it grow bigger and bigger?

The name of the theory is 'relativity'. Eh. No, I can't explain it. Go watch a tv show.

I just bought this book 'Why does e=m^cc? (and why should you care?)' but haven't read it yet. I'm guessing it will answer your questions.

Here, try this:
http://en.wikipedia.org/wiki/Theory_of_relativity

it needs to be at "relativistic" speeds, meaning speeds close to the speed of light.
light/energy travels at around 186,000 miles a SECOND. That is haul-ass. and that is as measured in a perfect vaccuum, such as in deep space.

on earth, light travels slower due to the atmosphere or as uit enters water. these things bend light, slowing it down, just like very strong gravity from stars/galaxies/black holes can as well.

Hey, thank you, I know about Einstein, and I've read some of his work, but I can't discuss with him cause he's dead. (@akprodr)

relativity is very complex. I am not expert on it, but it has been proven repeatedly, ad if we ever managwe to detect gravity waves, it will be proved once again.

rob, confirm deny or extrapolate from this stuff i heard - isn't it true that newtonian physics is a crock and practically all physics are wrong based on what they know now, but the top dudes don't want to rewrite the rules cos they are too comfortable?

Newtonian physics is practically useful but it is theoretically false as it doesn't recognize the speed limit of light. It isn't so much that the 'top dudes' are 'too comfortable' as much as the caveat of relativity is negligible when operating at terrestrial speeds.

Newtonian physics are dead-on and totally still used when it comes to objects that fit our sphere of size and mass. newtonian physics nearly perfectly can explain most of the Universe visible to us. Where it fails, and this is where physics find themost interesting projects to work on, is when we deal on a super scale, of either super massive (black holes, galactic centers, etc) or the super small (the "quantum" world)

Newton's laws are always valid when it comes to our scale.

exactly.
Newton was such a fucking genius. imagine what he culd have done with the data we have NOW!

Personally speaking, I don't think it's historically accurate to make Newton to be a run-of-the-mill enlightenment hero. Newton was far more complex than that. It's a fact of history that Newton wrote more on religion than he did on natural science and he was no deist. Newton held rather radical and, for his time, heretical religious views.

Genius mathematician, though, of course.

that is true, but for all his genius he was still a man of his time, a nd in his time theology and mathematics shared an equally lofty position.

some would argue mathematics is God

Or the infinity of infinities.

it may be the language of "god" I guess...

Pythagoras had a fun time with it, just don't mention irrational numbers.

Not true. They did an experiment using clocks: one ground based and one on a commericial style jet (prob 707 or something). With very sensitive clocks, they could measure that time went slower for the jet or vise versa.

With an equally sensitive mass measuring device, they probably could have measured that too.

die, earthmen; die.

the faster you walk toward the spin of the galactic arm in regards to the fabric of space-time, the slower 'time' moves.

horseshit.

tell that to the bow shock.