• Member Since 20th Nov, 2017
  • offline last seen 3 hours ago

Eroraf86


An astrophysicist who uses ponies to escape the madness of reality.

More Blog Posts8

May
14th
2021

Random musings about time, space, and black hole evaporation · 9:15pm May 14th

First of all, watch this if you haven't already.

So basically, according to our current models, the universe will expand forever, all the stars will eventually die, and black holes will be the only noticeable things left. But of course, even black holes are not eternal; over time, they evaporate, and finally disappear in a burst of radiation. The last black holes can be expected to evaporate somewhere shy of a googol years from now.

Yes, you read that right. A googol years. As in 10100. As in an incomprehensibly long time.

Let's try and fix that, shall we?

Let's start with something small and familiar, like a human hair, which is about 0.1 mm wide. How do you think that compares to, say, THE ENTIRE OBSERVABLE UNIVERSE? Well, the observable universe is roughly 100 billion light-years wide, and a light-year is about 10 trillion km. Put it all together, and you get the diameter of the observable universe in hair-widths, which is about 1031, or 10 million trillion trillion.

That's a lot of hairs. But we're not done yet.

That big number up there? The number of human hairs that you could fit across the entire observable universe? CUBE IT.

That's right: if you filled THE ENTIRE UNIVERSE with hairs, chopped every single one into pieces as tall as they are wide (so, a 10 cm strand would become 1000 little pieces), and then compared the size of one of those little pieces to the size of THE ENTIRE FyayING UNIVERSE, now you know how big a googol is.

Oh, and funny story: the universe as a whole has only existed for about 13.8 billion years. Order of magnitude, that's 1010. That's literally less than a rounding error.

Yeah. Space is BIG. And it's only going to get bigger as time goes on.

Comments ( 5 )

Time, it's more like a big ball of wibbly-wobbly, timey-wimey stuff.

5518769
Not in this universe. Depending on who you ask, the laws of physics may go out of their way to prevent time travel to the past. Stephen Hawking called it the Chronology Protection Conjecture.

Space is the hole in which we're all floating. Or something like that.

5518774
Didn't you get my reference?.

5519113
Of course I did, you silly. "Blink" is one of my favorite episodes. Even if it did give me a few bad nights, lol.

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