How do we know that stars exist some billion years far?

[TouK]

The age of universe is said to be around 13 billion years.However we know that stars exist 40 billion years far!

Since the fastest means we have is the light then how do we know about their existence?

[Moontanman]

The age of universe is said to be around 13 billion years.However we know that stars exist 40 billion years far!

Since the fastest means we have is the light then how do we know about their existence?

 

 

Please give some evidence of that assertion...

[TouK]

I saw it on documentaries or science blogs and i consider it true.If someone has evidence on another theory then he can post it.

[Moontanman]

40 billion light years away does not mean the light started 40 billion years ago...

 

http://en.wikipedia.org/wiki/Universe

 

 

Current interpretations of astronomical observations indicate that the age of the Universe is 13.772 ± 0.059 billionyears,^[14] (whereas the decoupling of light and matter, see CMBR, happened already 380,000 years after the Big Bang), and that the diameter of the observable Universe is at least 93 billion light years or 8.80×10²⁶ meters.^[15]According to general relativity, space can expand faster than the speed of light, although we can view only a small portion of the Universe due to the limitation imposed by light speed. Since we cannot observe space beyond the limitations of light (or any electromagnetic radiation), it is uncertain whether the size of the Universe is finite or infinite.

 

 

 

The current estimate of the Universe's age is 13.772 ±0.059 billion years old.^[14] Independent estimates (based on measurements such as radioactive dating) agree at 13–15 billion years.^[38] The Universe has not been the same at all times in its history; for example, the relative populations of quasars and galaxies have changed and space itself appears to have expanded. This expansion accounts for how Earth-bound scientists can observe the light from a galaxy 30 billion light years away, even if that light has traveled for only 13 billion years; the very space between them has expanded. This expansion is consistent with the observation that the light from distant galaxies has been redshifted; the photons emitted have been stretched to longer wavelengths and lower frequencyduring their journey. The rate of this spatial expansion is accelerating, based on studies of Type Ia supernovae and corroborated by other data.

[TouK]

In conclusion the reason is the expansion of the universe right?

[Moontanman]

Precisely...

[TouK]

Thank you

[Moontanman]

No problem...

[alpha2cen]

In conclusion the reason is the expansion of the universe right?

Using modified Beer Lambert Law, I tested the Steady State Universe theory.

But I could not fit the obtained redshift data to that model anyway.

http://www.scienceforums.net/topic/71791-light-interaction;-calculated-results-about-the-steady-state-universe/#entry720407

The blue line is a redshift data line, and the red line is a model data line.