To continue with the theme...

In the Late 1950s a little girl named Virginia asked the New York Times if there was a Santa Clause. The reply is now famous. Someone thought it would be fun to ask the scientists at NASA the same question.

Here is NASA's reply:

No known species of reindeer can fly. But there ARE 300,000 species of living organisms yet to be classified, and while most of these are insects and germs, this does not completely rule out flying reindeer, which only Santa has seen.

There are two billion children (under 18) in the world. But since Santa doesn't appear to handle Muslim, Hindu, Buddhist and Jewish children, that reduces the workload to 15% of the total – 138 million or so. At an average rate of 3.5 children per household, that's 91.8 million homes.

One presumes there is at least one good child in each. Santa has 31 hours of Christmas to work with, thanks to time zones and the rotation of the earth, assuming he travels east to west.

This works out to 822.6 visits per second.

This is to say that for each household with good children, Santa has 1/1000th of a second to park, hop out of the sleigh, jump down the chimney, fill the stockings, distribute the remaining gifts under the tree, eat snacks, get back up the chimney, get back into the sleigh, and move to the next house.

Assuming that each of these 91.8 million houses are distributed evenly (which we know to be false but for the sake of these calculations we will accept) we are now talking about 0.78 miles per household, a total trip of 75.5 million miles, not counting bathroom stops. This means that Santa's sleigh is traveling at 650 miles per second, 3,000 times the speed of sound.

For comparison, the fastest man made vehicle, the Ulysses space probe moves at a poky 27.4 mps. The average reindeer runs at 15 mph.

The sleigh's payload adds another interesting element. Assuming that each child gets nothing more than a medium sized Lego set (2 pounds), the sleigh is carrying 321,300 TONS, not counting Santa, who is invariably described as overweight. On land, conventional reindeer can pull no more than 300 pounds.

Even granting that "flying reindeer" (see first paragraph) could pull TEN TIMES the usual amount, we cannot do the job with 8 or even 9. We need 214,000 reindeer.

This increases the weight, not even counting the sleigh, to 353,430 tons. Again, for comparison this is 4 times the weight of the British liner Queen Elizabeth 2. 353,000 tons traveling at 650 miles per second creates an enormous air resistance. This will heat the reindeer in the same manner as a spacecraft re-entering the earth's atmosphere. The lead pair of reindeer will absorb 14.3 QUINTILLION joules of energy..... Per second ....Each!

In short, they will burst in flame almost instantaneously, exposing the next pair of reindeer,and creating deafening sonic booms in their wake. The entire team will be vaporized within 4.26 thousands of a second. Santa, meanwhile, will be subjected to centrifugal forces 17,500.06 times the force of gravity. A 300 pound Santa would be pinned to the back of his sleigh by 4,325,015 pounds of force.

CONCLUSION: There was a Santa, but he's dead now.