If there's a speed of light, is there also limit of distance traveled by light?

Answer 1

There is no question that light obeys its speed limit. And I agree with the many others who said that light will travel to infinity unless it is absorbed by matter. But what if there were a distance limit? Now it may not make sense to say that a photon of light has a distance limit, but it could possibly be correct that photons of light have a lifetime, albeit very very long.

Science theorizes that the 3-degree Kelvin background radiation we see everywhere is what is left from the initial Big Bang. Based on this temperature, cosmologists tell us the universe is somewhere between 11.2 billion to 20 billion years old. BUT, what if photons decay like radioactive particles and have a half-life? What if their half-life were 1 billion years? There would be too much 3-degree background radiation around to be explained by a universe between 11.2 billion and 20 billion years old. So the universe would have to be much younger and as a consequence, much smaller.

Your question provoked a cool idea which I'm sure has been provoked' before.

Answer 2

Maybe.

It depends on wheter you think the Universe is infinate. If space is flat, then it could go on forever. If space is eliptical, then it would go out but come back to where it started from the other direction. If space is hyperbolic, then it will be bent back on itself.

The debate on the "shape" of the universe is still going on.

Also, with the universe only being 10 Billion years old (oops. time for another birthday card), only stars within 10 Billion light-years would be visible to us.

Someone said:
I think so, because if you look at the night sky in a rural area,
you can't see every single star that's there because some are
too far away to see.

Yes, but the energy of the light diminishes by the square of the distance. Also, intervening stallar dust can absorb some of the light.

Answer 3

Assuming the light is not absorbed by an object, light can propagate forever. But there is a caveat, space (even completely devoid of matter is not nothing, it is something that can be bent, stretched, etc. by what we call fields (electrical, magnetic, gravitational, etc.) Light is made up of electrical and magnetic fields traveling together and as such affect space but also use it as the mediium through which light can propagate. When that space ends, light can no longer propagate. It is believed now that that space has an end, but that it itself is propagating (remember the Big Bang Theory?), so the distance that light can travel is itself increasing (we are talking about the limits or ends of the universe here!).

Answer 4

Theoretically there is no limit, but practically the intensity of the light diminishes in proportion to the distance squared, so the light becomes very difficult to detect as the distance from the source becomes very great.

Answer 5

Theoretically light will continue to travel in a straight line away from its source until it is reflected or absorbed by matter. But since it can travel through a vacuum and is not subject to any sort of drag or friction, it can travel an unlimited distance.

Answer 6

Yes. The Universe was opaque for a short time after the Big Bang. So light cannot have travelled more than:

speed of light x age of universe = 14.5 billion light years.

Answer 7

There is no limit to the distance traveled by light. Unless there is anything to absorb it, it will travel for ever.

Answer 8

when light travels thru space the energy of the light diminishes.the light shifts from visible region to infrared region where its wavelength is more and energy is less.thats y scientists use big new telescopes to capture that low level light radiations and study it.
our eyes may not see the light from the stars but when certain devices are used to study the stars can be seen.
ever wondered how scientists got the very far distant star images.

Answer 9

186,282.397 miles per second. I don't care about what anyone says. There is no way of knowing the answer to the second half of your question. There are to many variables to consider when trying to calculate the limit of distance.

Answer 10

light can travel forever but it does not because it gets scattered thru particles present in the air.since stars are very far away from us their light reaches us millions of years later.so if a star gets destroyed today say by supernova we would cone to know of it some million years later