# If we know the distance of a distant light emitting object, how could we know the age without knowing how long the light has been here?

I have been contemplating the age of our observable universe and I was unsure as to how we could tell the age by only divdeing the distance by the constent with out knowing how long the light has been here. Wouldn't that only tell us the minimum of elapsed time.

• without duration only the minimum of time can be calculated we do not know how long the light has been here> billy bob – Apprentice DR NormanERustJR. Jan 29 at 15:13

The age of the universe is not measured to be the radius of the observable universe divided by the speed of light. In fact, the observable universe is much, much larger than this. The age of the universe is measured by using certain cosmological models (usually the $$\Lambda$$CDM model) and reconstructing the time of the Big Bang from observed values of the known densities of different types of matter.

https://en.m.wikipedia.org/wiki/Age_of_the_universe

• If it took mass of different densities 13,7 billion years to expand to the distances we have observed and detected how far has the light traveled. Do you think that we have seen and detected all the mass in the universe of an eternity in an infinity. if we have calculated the densities of mass I was wondering Do you think we could trace the red shift velocities of equally distance objects using the speed increase of 550 kms per mega parsec that are traveling at a 90 degree angle from each other to find the point of expansion. – Apprentice DR NormanERustJR. Jan 29 at 15:56
• I honestly have no idea what you’re asking here. – Bob Knighton Jan 29 at 18:03
• Perhaps I do not even know what I am asking. I shall try to express my questions better. Do you really believe that all the mass in the universe originated from one moment and expanded from there with no trace of any non uniformity showing up in the background radiation measurements made by C.O.B.E.of a dissipation at the point s of expansion. – Apprentice DR NormanERustJR. Jan 29 at 21:28
• It’s important to realize that the Big Bang model doesn’t describe the contents of the universe emerging from s single point. Rather, it describes a rapid local expansion of the distance between nearby points in space. The Big Bang model is better described as a stretch rather than a bang, and the nomenclature is rather unfortunate. – Bob Knighton Jan 29 at 21:51
• Further, scientists typically don’t “believe” things. The current cosmological models upon which we base the current Big Bang model are highly supported by the available astronomical data. – Bob Knighton Jan 29 at 21:53