The observable universe: The part we can see

Observable universe, on hearing, might sound like the amount of universe we have observed so far. But that is not what it is. So the observable universe (with a diameter of 93 billion light-years) is the region from which light has had the time to reach our Earth so far.

Let me explain. So, as we all know, our universe is about 13.8 billion years old. This means that the light from the distant object has to travel about 13.8 billion years. 

And as no object can travel faster than the speed of light. However, the universe or space is expanding faster than the speed of light. So light has to travel this obscure amount of space, and it is getting redshifted (I have discussed redshift in detail in one of my previous posts.)

Some amount of this redshifted light is significant so we can see it. But the light of the bodies far away from us is getting redshifted to the radio spectrum, which cannot be seen by us.

But don't worry as the observable is, in fact, constantly growing.

I hope you found this post helpful. 

See you next Sunday!