Santa's Science

Krauss has considered similar problems in his work on the physics of Star Trek. The starship Enterprise gets by with devices called 'inertial dampers' to cushion the forces that Captain Kirk feels in the seat of his pants. Santa has to resort to similar tactics, creating an artificial world within his sleigh in which the reaction force that responds to the accelerating force is cancelled, perhaps by some kind of gravitational field.

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There is one other problem Santa has to contend with. His cargo of toys. Assuming that each of the 2,106 million children gets nothing more than a medium -sized construction set (900g or 2lb), he has a load of 1,895 million kg (4212 million lb) to convey. Then there is also his supply of fuel to achieve these huge speeds.

Any way you look at it, Santa has some serious hurdles to overcome.

The US Air Force 48th Fighter Wing claims to use satellite dishes to track Santa on Christmas Eve, with other Air Force Space Command squadrons around the world, to prevent the unnecessary scrambling of interceptor aircraft and ensure the safe arrival of 'the Jolly Old Elf' and all his presents. 'We have some of the most sophisticated equipment in the world. The deep space tracking system was constructed at a cost of over $600 million. Santa is in good hands,' said Tech. Sgt. Ray Duron, Crew Chief of the 5th Space Surveillance Squadron at RAF Feltwell, which coordinates the route of his sleigh with the 1st Command and Control Squadron in Colorado Springs.

Given the extraordinary array of technology already used by Santa, much of which is beyond the capabilities of the US military, this annual 'Santa Track' - which dates back to 1957 - seems unnecessary. Indeed, some might say it is merely a publicity stunt engineered by defence scientists to draw attention away from the vast range of scientific and technological achievements pioneered by Santa to ensure children across the world are not disappointed on Christmas morning.

An abridged extract from Can Reindeer Fly? The Science of Christmas by Roger Highfield (c) By permission of Little, Brown and Company, Inc. All rights reserved. To purchase copies of this book in America please call 1-800-759-0190

Available to buy from Amazon.co.uk and - as The Physics of Christmas - from Amazon.com

Roger Highfield is Science Editor at The Daily Telegraph and the co-author of the bestseller The Arrow of Time.