In another episode of The Guide to Space. We talked about how big is our universe?
And then I said it all depends on whether the universe is finite or infinite
I mumbled, did some hand waving, glossed over the mind bending implications of both possibilities
And then moved on to whatever snarky side cult reference was next because I'm, I'm a bad host
I acted like nothing happened and immediately got off the elevator. So in the spirit of he who smelled it delt it.
I'm back to shed my cone of shame and talk big universe.
And if the universe is finite, well it's finite
You could measure its size with a really long ruler. You could also follow up statements like that with all kinds of crash shenanigans.
Sure it might wrap back on itself, in a mind bending shape
Like a monster doughnut or nerd decahedron
But if our universe is infinite all bets are off
It just goes on for ever and ever and ever in all directions
And my brain has already begun to melt in anticipation of discussing the implications of an infinite universe
Haven't astronomers tried to figure this out? Of course they have! Fragile mortal/meat/man/woman.
They have obsessed over it
And ordered up some of the powerful sensitive space satellites EVER built to answer this question
Astronomers have looked deep at the cosmic microwave background radiation, the afterglow, of the big bang
So how would you test this idea just by watching the sky?
Well here's how smart they are
They've searched for evidence that features on one side of the sky
Are connected to features on the other side of the sky
Sort of like how the sides of a Risk map connect to each other
Or how there's a wrap around on the pac man board
And so far,
There's no evidence that they're connected.
So in our hoo-man (human) words this means 13.8 billion light years in all directions
The universe doesn't repeat
Light has been travelling towards us for 13.8 billion years this way
And 13.8 billion years that way
And that's just when the light left those regions
The expansion of the universe has carried them from 47.5 billion light years away
So based on this, our universe is 93 billion light years across
And that's an at least figure
It could be 100 billion light years
Or a trillion light years
We don't know
And possibly, we can't know
And it just might be infinite
And if the universe is truly infinite,
Well then we get a very interesting outcome
Something that I guarantee will break your brain for the entire day
After moments like this I like to douse it in some XKCD, Oatmeal, and maybe some Candy Crush
So consider this, in a cubic meter or yard of space
Alright in a box of space about yay big
There's a finite number of particles that can possibly exist in that region
And those particles can have a finite number of configurations considering their spin, charge, position, velocity and so on
Now, Tony Padilla from Numberphile has estimated that number to be 10 to the power of 10 to the power of 70
And that's a number so big that you can't actually write it out with all the pencils in the universe
Assuming of course that other lifeforms haven't discovered infinite pencil technology or there's a pocket dimension containing only pencils
Actually, it's probably still not enough pencils. There are only 10 to the power of 80 particles in the observable universe
So that's much less than the possible configurations of matter in that cubic meter
So if the universe is truly infinite if you travel outwards from earth eventually you'll reach a place where there's a duplicate cubic meter of space.
And the further you go, the more duplicates you'll find
(Sarcastically) Oh big deal, you think, one hydrogen pile looks the sames as the next me
Except, you hydro-maticist, you'll pass through places where the configuration of particles will begin to appear familiar.
And if you proceed long enough you'll find larger and larger identical regions of space.
And eventually, you'll find an identical you. And finding a copy of yourself is just the start of the bananas crazy things you can do
in an infinite universe
In fact, hopefully, you'll absorb the powers of an immortal version of you because if you keep going you'll find an infinite number of yous.
You'll eventually find entire duplicate observable universes with more yous, also collecting other yous
And at least one of them is going to have a beard.
So what's out there? Possibly an infinite number of duplicate observable universes
And we don't even need multiverses to find them. These are duplicate universes inside our own infinite universe
And that's what you can get when you can travel in one direction and never EVER stop.
So whether the universe is finite or infinite is an important question, and either outcome is mind blenderingly fun.
So so far, astronomers have no idea what the answer is but they're working towards it and maybe someday they'll be able to tell us.
So what do you think? Do we live in a finite or infinite universe? Tell us, in the comments below.
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[Bloopers] Fraiser Cain: Something that I guarantee will break your bane (grunts in frustration) break your bane
Off camera: Your bane is broken Fraiser: I've broken your bane, like bane (laughs)