Regarding the Speed of Light & the Universe?

Question

So, we know that nothing in this Universe is faster than Light. Light travels at an orgasmic speed of +- 300,000 kilometers per second!
The speed of light has been discovered in the last couple of centuries (maybe +- 100 to 200 years ago for argument's sake)
Then how come we know the age of the Universe, or the known diameter of the known Universe. In theory, the Universe is approx. 4-5 Billion Lightyears in diameter!
How do we know that a Galaxy is 4 million Lightyears away. In order to get that 4, the light must travel 8 million years (4 there and 4 back). According to that theory, the Dinosaurs know about the speed of light!
Can someone please answer this difficult question?

Answer 1

light doesn't have to travel back and forth for you to see it.

only into your eye.
how does that theory prove the Dsores know about it.
dinosaurs cannot comprehend the speed of light.

Answer 2

We can use many different ways to calculate these facts.

1) The size of the Universe. It is assumed that the Universe is expanding at a rate slightly less than the speed of light. This assumption is based on the fact that the Big Bang sent matter flying in all directions at nearly the speed of light. If you assume that the Big Bang happened 5 billion years ago, then the universe would be 5 billion lightyears across, give or take a few.

2) The distance of stars and galaxies. This isn't based on the speed of light. We estimate the distance using all sorts of guess work, including how bright the light from the star is, compared to the spectrum of light given off of it. Also, we can chart the relative position of distant objects as the Earth moves. A closer star will appear to move more quickly than a distant star.

I don't know if this helped at all. Much of what we know is determined by physics and mathmatics, not direct observation and testing. We take the information that we have and apply logic to reach a reasonable conclusion.

Answer 3

You are confused.1st.Current theory has the universe at about 14 billion light years,not 4-5 billion.Through the "red shift" effect,we see almost all galaxies receding from ours,the further away,the faster.Astronomer Edwin Hubble first noted this phenomena.By "rewinding"in effect,we see that everything was together about 14 bya when there was a BIG BANG.Where not just matter exploded,but space itself began expanding.What caused the big bang is still theoretical,that it happened isn't.
2nd,Your idea that light must travel "back and forth"is incorrect,light we see didn't shoot from our eyes,bounce off a star,and return to our eyes.It is a one way trip.

3rd,we are able to measure the distance to other galaxies through "Cepheid variables"(google it)

4th,How does any of that mean dinosaurs "knew" about the speed of light?Dinosaurs aren't thought to have possessed much intelligence,even if they did,the speed of light isn't dependent on something "knowing"it.Think of this,by your scenario that since light travelled 8 mil.LY(incorrect also,the Dino's died out 65 mya)the Dino's "knew"about it.Then since some stars are say,600 light years away,man must have "known" light speed further back than you stated.Doesn't make much sense,does it?Hope that helped

Answer 4

Just because you don't know something doesn't mean it doesn't exist.
We can tell how fast a light source is moving away from us by its Doppler Shift. The faster something is receding from us the more its light is shifted towards the red end of the spectrum.
If you take the positions of many objects now and you know how fast they are moving apart, then you can calculate when they were all at the same point. 14-15 Billion years ago. At the Big Bang.

Answer 5

Relativity


Speed of Light at 299792.5 km/s
Relativistic Time Dilation
Gravitational Time Dilation
Pulsars, Black Holes, Singularity
Wormholes (Length Contraction)
Dark Matter and Gravitational Lensing
Dark Energy, Redshifting and Expanding Universe
http://www.speed-light.info/relativity_quran.htm

Answer 6

In particular relativity, 2 plenty can't circulate quicker than the fee of sunshine relative to a minimum of one yet another. many times relativity, 2 plenty won't pass one yet another quicker than the fee of sunshine, however the area putting apart them interior the process their relative action can exceed the fee of sunshine. Even a small quantity of acceleration shrinks or expands area in share to distance, and extremely distant galaxies can therefor circulate to or removed from you plenty situations quicker than mild. Cosmological distances are measured interior the comoving coordinate equipment, wherein action because of the upward thrust of area basically does not count selection for purposes of particular or usual relativity.

Answer 7

Distances of the stars and galaxy is measured by different methods. One of the most important and accurate method is parallax method.Have look into the following URL

http://www.windows.ucar.edu/tour/link=/kids_space/star_dist.html&edu=high