The age of our universe is between 13 and 14 billion years old. We have many lines of evidence and reasoning that have brought us to this accepted understanding, one of which is our observational limits. Having the ability to point Hubble at any dark patch of sky and zoom in to most articulate point we can find stars, galaxies and any other number of things that exist no matter where we look, but it is also important to realize that there is much that we cannot see.
Imagine yourself in the middle of the Sahara desert or any other location sufficiently far enough away from any major city as to not be affected by its light. If you take a flash light out and point it around you in any direction (yes laterally, let’s not look up yet) you will find a bubble of the sand around you that is able to reflect enough light back and be seen. There is a gradient to a point where the light is just not bright enough to be able to reach your eye in its detectable range.
This is analogous to what is being seen with Hubble.
If you were to take your flashlight and slowly change it’s focal length as you are spinning around you will find that the light (now targeted and brighter with a more tightly compact beam) is able to allow you to see farther.
This is also being seen with our telescopes, only its not because we are shining light out. Our telescopes work by accepting light in, which means that as time goes on since we are seeing more things we must be having more light reach us.
Since the universe cannot contain anything that is older than itself we can follow logic down this beautiful path…
- Our primary detection methods are EM wave, from here on collectively referred to as Light, based
- Light may only be as old as the universe
- Light travels at a constant speed, referred to as C
- A light year is the distance that light may travel in a year
- Light radiates outward in a spherical shape
- An object may be no younger than the age of the light being detected
- We are detecting more objects as time goes on, at the far reaches of our vision in all outward directions
For every year that passes the light from a light year further from our detector is able to reach us. it follows that the age of the light being detected is older.
Since nothing may be within the universe that is older than the universe it follows that the oldest light, being the light from as far as it has been detected at this point in time, is coming from a point near the beginning of our universe. If light were evenly distributed and not growing in the detection bubble it would falsify this conclusion but with these observed facts it follows that if we can calculate a ballpark figure for the age of the light we can apply that figure to the universe as well.
This is all rooted in a little discourse i had with my father last night, and i apologize if it isn’t entirely clear. I will likely clean it up as time goes on and maybe ill even include the mathematical end of things.