How big is the universe?

Image for post
Image for post
The diameter of the known universe is 93 billion light-years, but the true width is 7 trillion light-years.

The universe is much larger than we know, however, it is most definitely a finite object. That is to say, it only takes up a certain amount of space. Given this to be true, the universe must be a specific size, within the hyperspace in which it is expanding. Unfortunately, there is really no way of knowing for sure just how big it truly is. There are ways to make basic approximations though.

Telescopes require light, so everything beyond a certain point is out of sight. That is to say, the full extent of the universe is so vast that we can only see a small part of it. This is because light travels at a speed of just less than 6 trillion miles per year, but the universe is way, way, way bigger than that. So, everything beyond a certain point is just too far away to ever be seen. Based on this observational restriction, anything further out than 46 billion light-years is invisible from the perspective of the Earth.

So, although it only seems to be about 93 billion light-years across based on this extremely limited point of view, the whole universe is actually much, much larger than that. Predictive models would seem to indicate that the complete expanse is probably more than a couple hundred times the size of this horizon. With that being said, and assuming all the calculations are correct, the entire universe is currently about 42 septillion miles wide.

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store