BIG.
Mindbogglingly BIG.
Or if you were to ask a five year old: “It has to be at least more than 4” (and she’s not wrong).
The hard part with trying to understand the size of the universe is that our brains don’t really deal with large numbers very well. A great example of this is with money. We often hear the terms millionaires and billionaires thrown about pretty regularly and they all just seem like nebulous rich people all about the same. To give you a better concept of the actual difference:
Eleven days, vs thirty two years. And the numbers just keep going up:
And one hundred quadrillion or 10^17 seconds is about the total age of the universe. Everything that has ever happened everywhere in the entire universe has happened in the past one hundred quadrillion seconds.
In theory, this gives us a basis for attempting to grasp the sheer enormity of the universe. The edge of the observable universe (yes, I said observable and we’ll probably go through what that means in another article) is in the range of 2.7 x 10^23 miles or 4.3 x 10^23 kilometers away from earth in any direction. Meaning the diameter of the observable universe is about 5.5 x10^23 miles or 8.8×10^23 kilometers. So this means there are more miles across the observable observable universe, than there have been seconds since the big bang. And not just a little bit more, like 5.4 million times more miles than seconds.
At this size, using miles or kilometers doesn’t even make any level of sense; our brains can’t even really fathom what that means. Most scientists use light-years as a measure of distance, which is the distance light travels in space in one year. One light-year is about 5.8 x 10^12 miles, so again, pretty big. But even that unit of measurement is pretty small in comparison to the vastness of our universe.
To try to bring this discussion a little closer to home the distance from earth to our closest star, named Proxima Centauri, is about 4.2 light-years away. If you could travel that distance at the speed of light, which we can’t even come close to yet (and is likely not possible in a conventional way), it would still take 4.2 years to get there.
And to give you an idea on how fast human beings have been able to travel so far: The record holder for “fastest speed that a human has ever achieved relative to Earth” is held by the Apollo 10 crew; clocked at 39,897 kilometers per hour. This speed is only 0.00003697 times the speed of light. At that speed it would take us 114,855 years to get to our nearest star.
And that is the nearest star. The edge of the observable universe is 46.5 BILLION light-years away from us. Traveling at our Apollo 10 speed, it would take 1,258,732,008,252,110 years to get to the edge of our observable universe.
So… yes, at least more than 4. And BIG.
Mind-bogglingly BIG.
Further info and links:
How big is the Universe via NASA