some parts of the universe may be travelling faster then light.?

Question

if the universe is expanding at an accelerating pace then there may be some parts that are travelling faster than the speed of light relative to us.

Answer 1

Uh... no. This is a completely flawed argument because NOTHING that started with a speed less than light can travel faster than the speed of light. Relativity ensures that.

Since as an object increases in speed, it takes more and more energy to accelerate it by the same amount (as predicted and verified from special relativity), no object with an initial speed less than that of light can ever be accelerated to the speed of light, no matter how big the acceleration is.

The idea that it's possible for a star to be moving faster than the speed of light relative to us, suggested by one of the previous answerers, is also flawed. Addition of velocities in the conventional sense (v1 + v2) only applies at low speeds. The correct formula to use is (v1 + v2) / (1 + v1v2 / c^2), which is derived from special relativity, and which tends back to (v1 + v2) in the limit of low speeds.

Answer 2

Calm down now, all you guys panting with excitement. No great new truth has been uncovered here.

Einstein already considered the Asker's possibility. He described a thought experiment of a moving train, on which one of the passengers shines a flashlight in the direction the train is going.

The train is going, say, a hundred miles an hour. Light travels at ... the speed of light (Einstein called it "c" as in e=mc^2). So, is the light going c + 100 mph?

No. The light is still going at "c", the speed of light. The math is too complex for me to show here, but trust me, it's been tested and found to be robust, that the speed of light cannot exceed the speed of light. If you've ever used a g.p.s., the fact that it works is proof that Einstien was right, and a lot smarter than any of you Askers here.

Answer 3

Although the universe is still expanding, there is no way that any part of the universe is expanding at a speed greater than light. Scientists now can see that the universe is expanding at a faster rate than before. If this is true, than how could any part travel faster than light? And, how could we observe it?

Answer 4

You're absolutely right..! Even though Einstein's relativity has shown that no material object can move through space at the velocity of light, there's no reason that space itself can't expand faster than light. Material objects like galaxies, stars, planets and you and I are embedded in space. Relative to our place in space other stuff could appear to be moving at or faster than the speed of light.

The so-called Hubble law of cosmic expansion also shows that for every 1-million more parsecs a galaxy is from us, its recessional velocity will be 70 km/sec faster. (1 parsec = 3.26 light years) Obviously there would be a distance beyond which galaxies would be receding from us faster than the speed of light.

And then there's that part of the Big Bang theory called inflation theory which says that immediately after the Big Bang the universe briefly expanded faster than the speed of light.

Answer 5

That is a possibility. If a star were traveling directly away from earth at say 100,000 miles per second and we on earth were traveling away from that star at 90,000 miles per second, yes the relative speed would be faster than the speed of light.

Which brings up the question; How would we know the star was there if we were outrunning the light from that star?

Answer 6

Thats neat, that would constitute time travel. Alternate dimensions and such.
You have thrown a wrench in the gears of my concept of time and space.
Suddenly nothing matters.

Answer 7

Yes, i know, which strengthens the Big Bang theory.

Answer 8

Put it this way......You prove that theory and you can keep the money and i'll receive the Nobel Prize.

Answer 9

Nope..

Answer 10

interesting