The Physics Behind Santa

Each year on Christmas Eve, Santa brings presents to approximately 210 million kids who are a part of approximately 70 million households. The laws of classical physics and quantum physics limit the possibilities that can be used to explain Santa’s journey using science because the duration of Santa’s journey and the huge number of presents that Santa has to carry make it less feasible to prove Santa’s journey using science. I sat down with MVHS Calculus teacher Jon Stark to see what he thought about Santa’s journey. He had some interesting thoughts on how classical physics and quantum physics may be used Santa’s journey, but many questions still remain unanswered.   

Classical physics & g-force

Between houses, Santa would have to accelerate at a very high speed to minimize the time he takes between houses, which means considerable force must be used by Santa throughout his journey. The force Santa needs to accelerate can be used in terms of G-force since G-force is used to describe large amounts of acceleration. “We’ve got 210 million gifts to carry. So we are talking about 100 million kilos which is significant mass to accelerate, to get to those feats,” Stark explained, ”So the G-force you have to reach in those milliseconds to get across there for that speed is pretty extreme.” The source of the force required to accelerate Santa may only be from possibly extremely strong reindeer.

Classical physics & thrust

The reindeer may have an even harder time because of the drag on Santa’s vehicle. Thrust is the force that is required to move Santa in air and is used to overcome not only the weight of his vehicle but also the drag of the vehicle. For an aeroplane, its engine provides the thrust required to move the aeroplane through the air. However, Santa’s reindeer must be able to provide the thrust to move Santa, his sleigh, and his presents through the air. “So I think the G-force is the big problem, and especially accelerating something through the atmosphere, that gonna have that sort of volume, the drag on it is going to be outrageous.” Stark said, “So how much thrust can a reindeer generate? That’s the question for me for classical physics.“ Drag is linearly proportional to mass, and because of the mass of Santa’s presents, his vehicle will be carrying a lot of mass, and he will encounter a substantial amount of drag.

Quantum physics & scale issues

Although using classical physics to evaluate Santa’s journey may be easier than evaluating it using quantum physics, quantum physics may prove that Santa’s journey is possible. The coherent superposition principle, a part of the current predictions about quantum physics, states that a single quantum states can be simultaneously made up of multiple states. Quantum physics deals with the working of elementary particles and atoms and states that a particle can be at two positions at the same time. Hence, it is difficult to attribute Santa Claus’s journey to quantum physics which does not apply to the scale that Christmas presents have. “Well, unfortunately the problem with quantum physics is it works incredible well on small scale, but we have extremely macroscale for all this stuff that is happening,” Stark explained.

Assuming that quantum physics can be applied on a bigger scale, there are still many questions to answer about how simultaneity that the coherent superposition principle discusses would be achieved. Stark questions, “So imagine he visits 70 million places, is he at 70 million places at once and are all gifts present at 70 million places at once and does each gift then remain at only one of those 70 million places and how do we achieve that?”

Relativistic Issues

Things do not always stay “normal” at high speeds, unfortunately for Santa. When something is going at a very high speed, relativistic effects produce changes it what are known as relativistic mechanical quantities which include time, length, mass and momentum. “Because I think you are going to find that Is it going to be necessary to exceed light speed to cover all the distances with the accelerations you have I am afraid you going to end up getting relativistic effects, and the G-force you have involved and from the velocities you’re gonna have to hit,” Stark said.

Stark’s Star Trek Transporter Model

Stark proposed that quantum mechanics may not be ideal if it is assumed that Santa has all the packages on one sleigh, but it may work if Santa could create presents on the way. “You could move elementary particles and assemble presents on the spot,” Stark proposed, “Something like a Star Trek transporter kind of deal [could work].”

A Star Trek transporter is a fictional machine that can teleport things by dematerializing, transporting and then reassembling an object. “That get’s difficult though ‘cause if you are going to disassemble anything to use as a for a transporter, you have to basically take it apart in a way that it brings it down to the elementary particle level and know all the information about it for reassembly.” he said. “That creates huge quantum mechanical problems because of the uncertainty principle.” The Heisenberg Uncertainty Principle states that the velocity and the position of an object cannot be measured at the same time, and scientists today do not have the tools to efficiently control what happens on the quantum scale, so a Star Trek Transporter may not be the answer.

“The Star Trek transporter as shown in the Star Trek: The Next Generation is where teleportation happens. Santa may use such a machine to teleport presents by dematerializing, transporting and then reassembling them.” (Wikimedia/Konrad Summers)
“The Star Trek transporter as shown in the Star Trek: The Next Generation is where teleportation happens. Santa may use such a machine to teleport presents by dematerializing, transporting and then reassembling them.” (Wikimedia/Konrad Summers)


There are many problems with using classical and quantum physics to explain Santa’s journey because of the mere time he has to complete this journey and the number of presents he has to deliver. Hence, maybe it is best to attribute Santa’s journey to magic instead of physics.