# The impossibility of infinity!

#### perfect_world

There are none I can think of, as I couldn't understand them. I'd love to be able to understand them one day - if it turns out to be feasible.

Was wondering if any of the heavyweights in this forum are interested in these phenomena.

#### CRGreathouse

Forum Staff
There are none I can think of, as I couldn't understand them.
You could start with the event horizon size vs. mass of the black hole, which very simple (though not so simple to derive!).

Was wondering if any of the heavyweights in this forum are interested in these phenomena.
Probably best to ask in our physics forum, which would have more interested and knowledgeable people.

#### Awake

What about how there are infinite points on a line. Break a line in half: 1/2. Another half: 1/4. Then: 1/8, 1,16, 1/32, etc. The denominator amount has no limit. All of those intervals ACTUALLY EXIST on the line, so an infinite amount therefore exists in reality.

#### Pierce

Infinity only becomes impossible when you try to define it as a definite value. Saying it doesn't exist because you never reach it is missing the point(!) of its notion.

Its a bit like saying tomorrow doesn't exist....because we never reach tomorrow. Infinity, like the concept of 'tomorrow' is a notion, not a definite value that you can see, or hold, or calculate.

IMO.

Sent from my GT-N7100 using Forum Fiend v1.2.7.

#### CRGreathouse

Forum Staff
I have a rule of thumb that anything which says "infinity" is not actually mathematics. This is because there are a large number of mostly-unrelated concepts of the infinite in mathematics, and an actual mathematical usage would distinguish which one was being referred to.
Sidenote: I expand on this slightly here: philosophy - How big is infinity? - Mathematics Stack Exchange

#### CRGreathouse

Forum Staff
Infinity, like the concept of 'tomorrow' is a notion, not a definite value that you can see, or hold, or calculate.
You can certainly calculate it in IEEE arithmetic!