Surprisingly enough, I have never seen scientifical proof that denies the existence of Santa Claus. So I figured it is time to show some simple calculations that does this.

First we have to calculate the distance Santa and his flock has to travel. In other words, calculate the average distance between every human.

In July 2000 there were 6080671215 people on earth. Since there has to be just as much Evil as there is Good in the world, Santa will only visit half of these. This eases Santa's job, since there now are only 3040335607 people left.

To calculate the average speed he has to maintain is simple:
510072000000km / 24h

Which leads to the following conclusion: Santa would vaporize the second he started to accelerate. The friction caused by this speed would also heat up the air so much that the surface of the earth would probably melt. And this calculation does not even include the time he needs to land the sleigh, climb down the chimney, unload gifts, eat cookies, drink milk, climb up the chimney again, and take off.

But what if there were more than just Santa? for instance, one million Santa?s (MegaSanta) who split the work between them? 2 seconds of thinking should lead to the conclusion that one MegaSanta would occupy too much space in the air, and if there were one MegaSanta, all of these Santa's would still need to travel 21.253Km/h. A Gigasanta has to travel at 21Km/h to cover the distance, which is very slow, but still, the space needed for one billion Santas to fly safely is more than the atmosphere can hold. Yes, Santa may also orbit around the earth, but how would 1 billion fat and jolly men, a bunch of helpfull elves, and 8 billion reindeer fit onto the North Pole?