Quote Originally Posted by poop
If 2+2=4 today and has been so every time it's been tested, that is convincing evidence, but it is not proof.
The proof is in our ability to count. I could count apples for the rest of my life, and my famous last words will be "yes, 2+2=4". Even if I live to be seventy billion years old.

Things can be proven, some things cannot be disproven. Maths is probably the best example of something that cannot be disproven. The proof is all around us, all the time. It's not going to take you longer than an hour to travel 60 miles at an average of 60 mph. Water boils at 100 degrees celcius*, by definition. That isn't going to change unless you start meddling with the variables, such as salinity, pressure etc. I can also prove chickens lay eggs, and cats do not. I can't prove that humans are (or are not) warming the planet up though, and neither can anyone else.

(* pure water at sea level blah blah)