If the speed of light is relatively the same to all objects no matter the velocity, then how do we know that earth isnt moving at 99% of C? If we were moving at that speed, C will still appear the same as if earth was moving 50% of C right? So how do we know our velocity compared to C if the speed of light remains constant under all conditions?

If the speed of light is relatively the same to all objects no matter the velocity, then how do we know that earth isnt moving at 99% of C?

 

Relative to what?

The speed of light is constant for all observers relative to the observer. No one will percieve light as travelling slower or faster than approx. 3.0x10^8 m/s. Thus it would be possible for us to be travelling near the speed of light without being aware of it. But relative to what? Is there some "stationary" reference that we can relate our movement to?

 

Although, I don't believe that we've found any stellar body to be moving away from us (or us moving away from it) at that speed, which is measured by the doppler effect: z = approx(v/c). if we were moving near the speed of light, say .99999c, the z value would be .99999. No z value has ever come that close to 1. So I'd say it's unlikely that we are moving that fast, at least not to anything we can see in the sky.

The speed of light is constant for all observers relative to the observer. No one will percieve light as travelling slower or faster than approx. 3.0x10^8 m/s. Thus it would be possible for us to be travelling near the speed of light without being aware of it. But relative to what? Is there some "stationary" reference that we can relate our movement to?

 

Although' date=' I don't believe that we've found any stellar body to be moving away from us (or us moving away from it) at that speed, which is measured by the doppler effect: z = approx(v/c). if we were moving near the speed of light, say .99999c, the z value would be .99999. No z value has ever come that close to 1. So I'd say it's unlikely that we are moving that fast, at least not to anything we can see in the sky.[/quote']

 

Actually there have been z values for extremely distant galaxies that have been 3 or 4 or something. Want to say its impossible, that there is absolutely no way for anything to appear to be going faster than c? Well thats what I said, but I looked it up, and by gum it seems to be correct. So be sure to look it up before you come back and say that I'm wrong.

The speed of light is constant for all observers relative to the observer. No one will percieve light as travelling slower or faster than approx. 3.0x10^8 m/s.

 

 

Just a question, not to start an argument, but if the speed of light is indeed constant to an observer, then what is this red shift and blue shift that we keep hearing about?

Just a question, not to start an argument, but if the speed of light is indeed constant to an observer, then what is this red shift and blue shift that we keep hearing about?

 

If objects are moving towards or away from an observer the EM radiation given off by them goes through a change in frequency depending in the speed of the movement. We can measure the frequency of the light and compare it with emission spectrums and work out the shift in frequency and from that deduce the velocity of the object.

Z-values > 1 account for the expansion of the intervening space. No object moved faster than c in local space.

Well I'm assuming that we can assume that we are not movign anywhere near that fast because we probably wouldn't see light from many other objects because it would blue/red shift right off to the edges of the spectrum.

what a wonderful question.

it is indeed correct that we are not moving that fast in relation to what we can observe, however, an explotion like the big bang (or rather like "a" big bang) would send matter rushing away from the epicenter at such incredibly high speeds that it may actually be fisible.

We do infact use telescopes that measure light in other frequencies than visible light....