Originally posted by: RichardE
Originally posted by: DrPizza
The majority of people can't fathom numbers above a billion. A few people can comprehend numbers in the trillions and a little beyond. I don't think anyone can comprehend a number as large as Graham's number.
Hint: if you're going to write out that number, there are more digits in it than there are atoms in the universe. WAY more. And, that comparison is like comparing the Pacific Ocean to a drop of water. Well, that's not even close.
Whats the point of it though?
Can't you just keep getting larger numbers by taking his number and going +1
Well, you've nailed infinity down fairly well. Yes, of course you can. Relatively speaking, when compared to all numbers possible, Graham's number is incredibly small, virtually zero.
But, "can't you just keep getting larger numbers by taking his number and going +1"? Well, just how are you going to do that? Is number is so large that you can't write it down, even in scientific notation. The only way possible to write it down is to use some sort of special notation. (Knuth's up-arrow notation is one popular way of writing down fantastically large numbers.) However, that notation leaves enormous gaps where you have no way of writing down the numbers in the middle.
Imagine for a moment that you could only express numbers in scientific notation using 3 digits in the front. How would you write down a number between 1.11x10^100 and 1.12x10^100? There are .01x10^100 or 10^98 numbers between them. Well, of course, you can start using addition with a bunch of numbers written in scientific notation being added together. It's going to take a bit or writing though, but you can get any individual number between those two numbers written down on a few lines of a single page. However, once you get to numbers the size of Graham's number; the methods for writing those numbers down result in numbers so far apart that there isn't enough ink in the world to write down the numbers between them.
Oh, and in case no one mentioned it, Graham's number is actually useful. Well, sort of useful:
here.