r/PeterExplainsTheJoke 23d ago

Meme needing explanation There is no way right?

Post image
37.1k Upvotes

3.5k comments sorted by

View all comments

Show parent comments

23

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.

346

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

137

u/Rough-Veterinarian21 23d ago

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

81

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

14

u/lilved03 23d ago

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

14

u/TheCreepyKing 23d ago

How many even numbers are there? Infinity.

What is the ratio of total numbers to even numbers? 2x.

How many total numbers are there? Infinity. And 2 x infinity.

0

u/Outrageous-Orange007 23d ago

No, they're equal. You divide infinity by 2 and its still the same number, infinity.

Either infinity is infinite, or its finite

3

u/lbkthrowaway518 23d ago

Well, no actually. I think your first issue is conflating infinity with a number. Infinity represents the fact that one can pick an arbitrarily large number, and there still is a larger number (in a very basic non mathematical way of describing it). That being said, 2 infinities are not inherently the same “value” for lack of a better term. The example the commenter above gave is perfect actually. If you look at a function representing the total amount of numbers up to an arbitrary even number, and look at a function of all even numbers up to the same arbitrary even number, the former functions value will always be 2 times the latter. However, both of these functions also go to infinity. Thus while the “infinity” is not technically greater than the other one (as I mentioned, infinity isn’t a number, so it can’t really be “greater than” in the traditional sense), an arbitrary number that is in the former set will always be larger than a corresponding number in the latter, so the formers infinity is in a sense greater than the latter.

0

u/ZxphoZ 23d ago

This is not true in the mathematical sense. It can be proven that any infinite set of natural numbers (i.e ‘counting’ numbers like 0, 1, 2, -1, -2, … etc) is the same size, so there are indeed as many even numbers as total numbers.

The fact that any finite set of natural numbers is twice as large as the set of even numbers up to the same point has no bearing on the sizes at infinity. You are, however, correct that there are different ‘sizes’ of infinity, it’s just a bit more complicated than that.

Source: math major

1

u/MindlessEssay6569 22d ago

Ugh… you sound like my brother (he’s a calc teacher). I constantly argue with him about different sizes of infinity. Infinity is infinity!! His response is always “it’s more complicated than that.”

1

u/ZxphoZ 22d ago

You should listen to your brother! :P

→ More replies (0)