Physics of Santa, and Merry Christmas!

(Last Updated On: August 14, 2018)

Santa zeimusu thinking psi 200pxScience Fact: Santa Claus traces his origins to Saint Nicholas, a third century bishop who left secret gifts for the needy. In 16th century England the celebration of Saint Nicholas was moved from December 6 to Christmas Day. Thus a Christian religious holiday celebrating the birth of Jesus became associated with Santa Claus, gift-giving and shopping.

Faith and science exist in two different worlds; each claims to offer insight into the other, but those claims are rarely fulfilled. Therefore, today we will acknowledge the holiness and sacred origin of the Christmas season, but confine our comments to Santa.

We begin by considering the Physics of Santa, for which I am indebted to my friend George Rhodes, although it may have origins before him. (I have not verified the factual content.)

Physics of Santa


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 that only Santa has ever seen.


BUT since Santa doesn’t (appear to) handle the Muslim, Hindu, Jewish & Buddhist children, that reduces the workload to 15% of the total – 378 million according to Population Reference Bureau. At an average (census) rate of 3.5 children per household, that’s 91.8 million homes. One presumes there’s at least one good child in each.


This is due to the different time zones and the rotation of the earth, assuming he travels east to west (which seems logical). This works out to 822.6 visits/second. This is to say that for each Christian household with good children, Santa has .001 second to park, hop out of the sleigh, jump down the chimney, fill the stockings, distribute the remaining presents under the tree, eat whatever snacks have been left, get back up the chimney, get back into the sleigh and move on to the next house.

Let’s assume that each of these 91.8 million stops are evenly distributed around the earth (which, of course, we know to be false but for the purposes of our calculations we will accept). We are now talking about .78 miles/household, a total trip of 75.5 million miles; not counting stops to do what most of us must do at least once every 31 hours, plus feeding & etc. So Santa’s sleigh must be moving at 650 miles/second, 3,000 times the speed of sound. For purposes of comparison the fastest man-made vehicle on earth, the Ulysses space probe, moves at a poky 27.4 miles/second. A conventional reindeer can run, tops, 15 miles/hour.


Assuming that each child gets nothing more than a medium-sized Lego set (2 lb.), 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 lb. Even granting that “flying reindeer” (see #1) could pull 10 TIMES the normal amount, we cannot do the job with 8, or even 9 reindeer. We need 214,200. This increases the payload – not counting the weight of the sleigh – to 353,430 tons. This is four times the weight of the ocean-liner Queen Elizabeth.


This will heat the reindeer up in the same fashion as a spacecraft reentering 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 into flame almost instantaneously, exposing the reindeer behind them, and creating deafening sonic booms in their wake. The entire reindeer team will be vaporized within .00426 of a second. Meanwhile, Santa will be subjected to centrifugal forces 17,500.06 times greater than gravity. A 250-lb. Santa (seems ludicrously slim) would be pinned to the back of his sleigh by 4,315,015 lb. of force.

THEREFORE, if Santa ever DID deliver presents on Christmas Eve, he has since been annihilated into Higgs Bosons fleeing to the rim of the universe at near-light speed.

Science Speculation: We close this blog with an old, no, a very old story:

The Christmas Divorce

An elderly man in Hawaii calls his son in New York and says, “I hate to ruin your day, but I have to tell you that your mother and I are divorcing; forty-five years of misery is enough.”

“Pop, what are you talking about,” the son shouts.

“We can’t stand the sight of each other any longer,” his father says.  “We’re sick and tired of each other, and I’m sick of talking about this, so you call your sister in Florida and tell her.” And he hangs up.

Frantic, the son calls his sister, who explodes on the phone.

“Like heck they’re getting a divorce!” she shouts. “I’ll take care of this.”

She calls Hawaii immediately, and screams at her father, “You are NOT getting divorced! Don’t do a single thing until I get there. I’m calling my brother back and we’ll both be there in a few days. Until then don’t do a thing, DO YOU HEAR ME?” And she hangs up.

The old man hangs up his phone, smiles and turns to his wife. “They’re coming for Christmas and paying their own way.”

Do you have a story that relates Santa or Christmas to Science? If so, please share it with other readers!

Drawing Credit: zeimusu, on, modified


Physics of Santa, and Merry Christmas! — 4 Comments

  1. Art,

    I love that you were able to share the physics behind Santa. You shared this paper or one like it with me many many years ago, and I always wanted to find a copy of it and share it with my father in law, who is admittedly an admirer of physics and the science world. Now, here it is on your website, I’m sure you’ll have another loyal subscriber.

    • Great to hear from you, Dane! And hope your father enjoys the website too. Especially since he knows that science is sometimes tongue-in-cheek…

  2. Art:

    What great insight. I believe you have uncovered 2 remarkable findings here. 1) Santa is clearly responsible for global warming and 2)He was cloned as we can observe by visiting most any mall.

  3. Well, it’s obvious that you’ve overlooked a vital part of the calculation. What percent of those homes actually have a fireplace, and does Santa “skip” those houses or does he have some more-efficient way of “servicing” those households (such as throwing the presents through an open window, which wouldn’t require slowing down for each stop, though it might be kind of hard on the more fragile presents). You’ve also assumed there is only one delivery-person … what are all those elves doing once they’ve finished producing all the toys? Etc.

    About those reindeer … all the news services are currently circulating an article about reindeer and their abilities. I’ll list one of them here:

    (the original link is broken as of 6/16/2016 but here is another reference to the reindeer and their mushrooms:

    But the pertinent section of that article is near the bottom when it begins to examine whether reindeer actually fly, and there’s where I learned something new … they eat hallucinogenic mushrooms, so of COURSE they can fly once they’ve done that. Pretty much all bets are off once you know that little tidbit about them.

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