Size , Density and 10^40

Now many of us do wonder , what the size of universe is? Most consider it to be infinite. But there infact exists a horizon , that can also be considered as the size of universe , because what happens out of this horizon cant be found out.

This horizon is like a spherical bubblie centred on earth , with a radius of 13.7 billion light years and expanding at at rate of light moving outwards.

The reason for this is that we currently can only view light coming from a object 13.7 billion light years as light oculd have travelled only that much distance as of yet. As time passes , more universe comes into our view.Anything beyond this region cannot affect as potentially no information can be transferred .

One important fact is that the density of universe needs to be less tahn 5 g/cm^3 . If its more than the gravity would crush it soon into nothing . But even if it very very less than this , than universe would expand very very fast and thus no stars or galaxies could form . Currently it is estimated to be at .0211 g/cm^3 .

IN 1974 , Stephen Hawking gave a new result that black holes are continiously emitting radiation . The radiation increases with mass increase . And as mass is related to area of the hole created due to gravitational distortion increase with time , the black slowly radiated away its mass and dies .

Now there is another very peculiar and stunning result . There is a ratio 10 ^40. Lets call it X

1.Now when we measure the ratio of strength of electromagnetic force to gravitational force among atoms . It is X
2.If we measure ratio of most largest unit of time ( age of universe @ 13.7 billion years ) and smallest time unit ( time period of oscillation of nuclei ) . It is X
3.If we compute the lifetime of a star on it is X times the fundamental subatomic units .

4. If we find out total number of atoms in our horizon ( limited universe ) it turns out to be X squared .