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magicofthemind wrote:I expect there are, but they probably call them something that we can't pronounce.

Primtal, if you must know

Ted wrote:

JakeThePerformer wrote:But...

You might say that 13 is four times larger than three. For it is, and then some. At least I think it would be correct to say that.

You might think that it is correct but you'd be wrong, IMHO. It's the "and some" part that proves the error in your maths. 2+2=4, not "3 and some unspecified additional value". Indeed, the more I think about it and the more I rewrite my reply the weirder I think your idea on this is.

What Jake says can make sense in some contexts. Think of someone saying "The population of Brazil is four times the population of Spain". This is common usage and understandable to all, it would be missing the point to complain that the maths aren't exact.

Mr_Grue wrote:But if we multiply all known primes and then add 1...

But 1 is a prime number.

As is 2.

TheStoner wrote:

Ted wrote:

JakeThePerformer wrote:But...

You might say that 13 is four times larger than three. For it is, and then some. At least I think it would be correct to say that.

You might think that it is correct but you'd be wrong, IMHO. It's the "and some" part that proves the error in your maths. 2+2=4, not "3 and some unspecified additional value". Indeed, the more I think about it and the more I rewrite my reply the weirder I think your idea on this is.

What Jake says can make sense in some contexts. Think of someone saying "The population of Brazil is four times the population of Spain". This is common usage and understandable to all, it would be missing the point to complain that the maths aren't exact.

Sure, but in your example it's obvious that you are dealing with inexact numbers because the population is changing all the time. It makes sense to use approximations in such situations because they are easier to understand. When you are manipulating values that are smaller, easier to understand and *exact* then it would only be misleading and not at all useful to claim that 2+2=3.

Tomo wrote:

Mr_Grue wrote:But if we multiply all known primes and then add 1...

But 1 is a prime number.

As is 2.

Technically 1 isn't a prime, but it makes no odds to this:

1x1 + 1 = 2, which is a prime number;

and 1x2 + 1 = 3, which is a prime number;

and 1x2x3 +1 = 7, which is a prime number;

and 1x2x3x5 + 1 = 31 which is a prime number;

and 1x2x3x5x7 + 1 = 211 which is a prime number...

&c.


EDIT: corrected for my stupid.

Mr_Grue wrote:Technically 1 isn't a prime

I wrote that before my 8th cup of coffee.

Don't worry about it - you missed my "4" gaff.

You can also just multiply any amount of various different primes together and add 1 to get a prime.

Lawrence wrote:You can also just multiply any amount of various different primes together and add 1 to get a prime.

I might be wrong here but you would definitly have to include the number 2 in that equation otherwise you would always end up with an even answer if you multiply any amount of odd numbers together and then add 1 to the answer.

3x7 +1 = 22

AJ is correct.

You can create a new prime number by multiplying all the lower prime numbers and add 1.

The reason: When you multiply all your known prime numbers, you get a number that is divisible by all numbers up to that point, since any number which is not a prime number can be constructed as the product of prime numbers. By adding one, you now get a number that when divided by the lower numbers will always give a remainder of 1.

P1 x P2 x P3... x P(n-1) + 1 = Pn

This is the basis of Euclid's proof of infinite primes. There can't be a terminal prime, because the above process will always generate a further prime.

Now on to the diagonal proof of the non-existence of a list of all integers...

Tomo wrote:

Mr_Grue wrote:Technically 1 isn't a prime

I wrote that before my 8th cup of coffee.

1 is a prime.

edit: read my next post.

Wait now!

If you are suggesting, as you are now, that 1 is NOT a prime number, then you are suggesting that 2 is not the sum of two primes. In that case Goldbach 's conjecture should have been solved long ago!


EDIT: Okay, I appear to be a fool once again. Every number greater than 2. How did I forget that? Sorry.

Iff it breaks a rule you just make an exception for it
Like taking a limit