# The Naked Scientists Forum

### Author Topic: What is Infinity?  (Read 1325 times)

#### Don_1

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##### What is Infinity?
« on: 02/04/2012 11:04:58 »
+ 1 = ∞

The above must be wrong, because the ∞ in red obviously wasn't ∞. Therefore it follows that the answer ∞ has to be wrong.

∞ + ∞ = ∞

Again, the above must be wrong, for the same reasons as above.

∞ - ∞ = 0 (or possibly ∞) ????

I'm totally flummoxed here.

We live in one infinite universe. There can only be one universe, since it is infinite and there can surely only be room for one in infinity.

So, could it be that :

∞ = 1?

What do you think?        "RUBBISH!"

#### yor_on

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##### Re: What is Infinity?
« Reply #1 on: 02/04/2012 11:11:22 »
There are several answers to it. You can use numbers and split them into different categories as 'natural' and then state that this constitute a infinity as the natural numbers never runs down. Then you can spit each natural number and so state that this constitute proof for an even bigger infinity.

But infinity must still be infinity.

#### Ęthelwulf

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##### Re: What is Infinity?
« Reply #2 on: 02/04/2012 11:23:43 »
+ 1 = ∞

The above must be wrong, because the ∞ in red obviously wasn't ∞. Therefore it follows that the answer ∞ has to be wrong.

∞ + ∞ = ∞

Again, the above must be wrong, for the same reasons as above.

∞ - ∞ = 0 (or possibly ∞) ????

I'm totally flummoxed here.

We live in one infinite universe. There can only be one universe, since it is infinite and there can surely only be room for one in infinity.

So, could it be that :

∞ = 1?

What do you think?        "RUBBISH!"

I'm a little confused with your question. Are you saying that because infinity was on one side of your equation, it cannot purport to an infinity on another side? Well that would be incorrect. You also need to be careful with operations with infinity because many equations presumed to be correct are in fact invalid...

#### Ęthelwulf

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##### Re: What is Infinity?
« Reply #3 on: 02/04/2012 11:29:55 »
For instance, you cannot use infinity in arithmatic because it does not belong to a class of real numbers. So an finity minus an infinity is undefined.

#### syhprum

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##### Re: What is Infinity?
« Reply #4 on: 02/04/2012 13:15:57 »
I used to annoy my teachers by insisting that ∞ i.e 1/0 multiplied by zero i.e 0/1 must be unity as the zeros cancel out leaving 1/1.
I have since learnt the error of my ways i.e you can't use ∞ in normal arithmatic .

#### Pmb

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##### Re: What is Infinity?
« Reply #5 on: 02/04/2012 14:34:13 »
...What do you think?
The problem here may reside in the fact that you're treating infinity as a number when it really isn't. Infinity is a concept, not a number.

See http://en.wikipedia.org/wiki/Infinity
« Last Edit: 02/04/2012 14:43:22 by Pmb »

#### The Naked Scientists Forum

##### Re: What is Infinity?
« Reply #5 on: 02/04/2012 14:34:13 »