954
gatekeeping (mander.xyz)
you are viewing a single comment's thread
view the rest of the comments
[-] veniasilente@lemm.ee 25 points 11 months ago

Aren't there numbers past (plus/minus) infinity? Last I hear there's some omega stuff (for denoting numbers "past infinity") and it's not even the usual alpha-beta-omega flavour.

Come to think of it, is there even a notation for "the last possible number" in math? aka something that you just can't tack "+1" at the end of to make a new number?

[-] KmlSlmk64@lemmy.world 4 points 11 months ago

IIRC Depends if you talk about cardinal or ordinal numbers. What I remember: In cardinal numbers (the normal numbers we think of, which denote quantity, etc.) have their maximum in infinity. But in ordinal numbers (which denote order - first, second, etc.) Can go past infinity - the first after infinity is omega. Then omega +1. And then some bigger stuff, which I don't remember much, like aleph 0 and more.

[-] veniasilente@lemm.ee 1 points 11 months ago

So wait, you can't have numbers larger than infinity, but you can order them "past infinity"? I'm trying to wrap my head around the concept, and the clearest thing I can get at the moment is that the "infinity+1"th number is infinity... would that be right?

[-] weker01@feddit.de 2 points 11 months ago* (last edited 11 months ago)

No you can have numbers past infinity op is wrong.

As for how to order past the first infinity it's easy.

Of course first you have 1 < 2 < 3 < 4 < ... Then you take a new number not equal to any of the others let's call it omega. Define omega to be larger than the others. So 1 < omega, 2 < omega,...

This you can of course continue even further by introducing omega + 1 which is larger than omega and therefore larger than all natural numbers.

You can continue this even further by introducing a new number let's call it lambda that is bigger than all omega + x where x is a natural number.

This can be continued forever i.e. an infinite amount of times.

Edit: that is meant by ordinal number as you define a unique order each step.

The problem is that the concept of cardinality and ordinality is the same in the finite case. That is numbers that tell you how many things there are can also be used to sort them.

This does not work past the first infinity. If you add omega to the natural numbers then the amount of numbers you have is still the first infinity.

But there are bigger cardinal infinities than the first one. For example the cardinality of the real numbers. I.e. There are more real numbers than natural numbers.

load more comments (1 replies)
load more comments (18 replies)
this post was submitted on 11 Dec 2023
954 points (97.8% liked)

Science Memes

11068 readers
2852 users here now

Welcome to c/science_memes @ Mander.xyz!

A place for majestic STEMLORD peacocking, as well as memes about the realities of working in a lab.



Rules

  1. Don't throw mud. Behave like an intellectual and remember the human.
  2. Keep it rooted (on topic).
  3. No spam.
  4. Infographics welcome, get schooled.

This is a science community. We use the Dawkins definition of meme.



Research Committee

Other Mander Communities

Science and Research

Biology and Life Sciences

Physical Sciences

Humanities and Social Sciences

Practical and Applied Sciences

Memes

Miscellaneous

founded 2 years ago
MODERATORS