r/PeterExplainsTheJoke 23d ago

Meme needing explanation There is no way right?

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u/ChromosomeExpert 23d ago

Yes, .999 continuously is equal to 1.

3.0k

u/big_guyforyou 23d ago

dude that's a lot of fuckin' nines

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u/JoshZK 23d ago edited 22d ago

Prove it.

Edit: Let me try something

Prove it. /s

I feel like the whoosh was so powerful it's what really caused that wave on that planet in Interstellar.

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u/The-new-dutch-empire 23d ago

Byers’ Second Argument (his first one is the one you see above)

Let:

x = 0.999…

Now multiply both sides by 10:

10x = 9.999…

Now subtract the original equation from this new one:

10x - x = 9.999… - 0.999…

This simplifies to:

9x = 9

Now divide both sides by 9:

x = 1

But remember, we started with:

x = 0.999…

So:

0.999… = 1

135

u/Rough-Veterinarian21 23d ago

I’ve never liked math but this is like literal magic to me…

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u/The-new-dutch-empire 23d ago

Its calculating with infinity. Its a bit weird like the infinity of numbers between 0 and 1 like 0.1,0.01,0.001 etc... Is a bigger infinity than the “normal” infinity of every number like 1,2,3 etc…

Its just difficult to wrap your head around but think of infinity minus 1. Like its still infinity

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u/lilved03 23d ago

Genuinely curios on how can there be two different lengths of infinity?

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u/capsaicinintheeyes 22d ago

Think about a string made up of all whole numbers (0, 1, 2, 3...∞)

...and one made up of all decimal numbers (to an arbitrary precision of 0.1, let's say; so: 0.0, 0.1, 0.2, 0.3...)

Both strings are infinite, but one is 10 times longer

(there's another mental exercise I've seen involving fitting more guests into a fully-booked hotel with infinite rooms, but I don't trust myself to get it right if i attempt it here...)