You can't prove a negative!

[Fifty]

What on earth do people mean when they say that you can't prove a negative?

Does anyone actually believe that you can't prove a negative?

 

[Cheezy the Wiz]

It means that I only THINK half this bar is positive.

 

[Ziggy Stardust]

You can't prove some negatives.

What do I vote?

 

[Fifty]

You can't prove some negatives.

What do I vote?

Vote "false", because the sentiment expressed by the slogan is supposed to mean that you can't prove ANY negative. I mean, its stupidly obvious that you can't prove SOME negatives.

 

[bathsheba666]

If the negatives involve a republican religious pro-family-values senator and a rent boy, I'd say it's a given. Then again, who needs proof for this?

 

[TheBladeRoden]

You can't prove that you can't prove a negative

 

[Ziggy Stardust]

You can set up a scientific experiment to test the theory.

You need a cookie jar, one cookie and an appetite for a cookie.

 

[ParadigmShifter]

The square root of 2 is not a rational number.

Proof:

Suppose sqrt(2) is rational. Then it has a representation as a fraction p/q say with p, q coprime.

(p/q)*(p/q) = 2

=> p*p/q*q = 2

=> p*p = 2 q*q

Therefore, p*p is even (if p was odd, we would have p = 2k+1, and (2k+1)(2k+1) = 4k*k + 4*k + 1 which is odd).

Let p = 2k, Hence

4k*k = 2q*q

=> q*q = 2k*k

Therefore q is even. But then p and q are both even, contradicting that p, q are coprime. Therefore sqrt(2) is not a rational number.

QED.

 

[Thoughtful Thug]

What on earth do people mean when they say that you can't prove a negative?

Does anyone actually believe that you can't prove a negative?

I can't even prove a positive.

Unless I can go about stating a negation of the positive by allowing the remainer of what is left as simply null, and can't persist of ever being positive without the whole remaining sustainable.

 

[Perfection]

I have proven that you can't prove a negative:

Only positive statements can be proven
No negative statements are positive statements
Therefore you can't prove a negative (statement)

QED

 

[Thoughtful Thug]

I have proven that you can't prove a negative:

Only positive statements can be proven
Statements that are not positive are negative statements
Therefore you can't prove a negative

QED

Of course if one is inclined to go about believing inside the QED. Or else, all is folly.

 

[Cutlass]

-1 = -1

 

[azzaman333]

You can prove a negative.

 

[holy king]

what negative can you prove?

 

[Ziggy Stardust]

There is no cookie in the cookie jar.

 

[holy king]

ah, i see.

 

[BSmith1068]

But the bigger question is who stole the cookie from the cookie jar?

 

[azzaman333]

But the bigger question is who stole the cookie from the cookie jar?

I did.

 

[Masada]

You fat bastard, you fat bastard.

Way to much time at the Rugby once upon a time...

 

[luiz]

Of course there are some negative you can prove, but the statement is genreally valid as a principle, especially with regard to the Law. For instance, it is good to not have to prove that you're not a witch.