How Much Weight Would Santa Gain From Eating Milk and Cookies at Every House He Visits?

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iStock

Dave Consiglio:

This is a simple question for the Factor Label Method. This method, also known as dimensional analysis or unit analysis, make problems a breeze. I highly recommend it to anyone interested in doing seemingly hard math problems like this one. Here’s how you use it:

  1. Write your given—in this case “1 Santa Claus”—on the left side of your paper
  2. Write your desired answer—in this case “pounds”—on the right side of the paper
  3. Make a chain of units from left to right (no numbers required).
  4. Fill in the numbers
  5. Multiply by all the tops
  6. Divide by all the bottoms
  7. Clean up

In just 7 simple steps you’ve got an answer. Here’s my answer. (Note: I assumed a cookie has 200 calories and a glass of milk has 100 calories. Your results will vary based on the type of cookie. I also assumed around 2 billion houses.) Here’s my Factor Label Method:


Answer: 400,000,000 pounds.

One of the best things about mathematics of this kind is that, by approximating in this way, you can see the magnitude of your answer. This answer is 400 million pounds, but it might be 300 or 500 million, depending on your assumptions. So what?

Well, while we may not know the precise answer, what we do know is that the answer is very large.

This kind of answer can be really helpful. You don’t always have to have the precise answer. A “good enough” answer can give you a pretty good idea of where you stand.

By the way: We’re assuming that Santa burns no calories during his trip. If he burns calories like a normal man his size and age, he will probably only gain around 399,999,999 pounds. But if Santa uses calories to propel his sleigh around the world (perhaps he has a “fat to magic” converter?), then he might be able to travel the whole world using only the calories from his cookies and milk and gaining no weight at all. Magic is a tricky thing to quantify.

But for the real world, the Factor Label Method is the next best thing to magic.

This post originally appeared on Quora. Click here to view.

What is a Polar Vortex?

Edward Stojakovic, Flickr // CC BY 2.0
Edward Stojakovic, Flickr // CC BY 2.0

If you’ve turned on the news or stepped outside lately, you're familiar with the record-breaking cold that is blanketing a lot of North America. According to The Washington Post, a mass of bone-chilling air over Canada—a polar vortex—split into three parts at the beginning of 2019, and one is making its way to the eastern U.S. Polar vortexes can push frigid air straight from the arctic tundra into more temperate regions. But just what is this weather phenomenon?

How does a polar vortex form?

Polar vortexes are basically arctic hurricanes or cyclones. NASA defines them as “a whirling and persistent large area of low pressure, found typically over both North and South poles.” A winter phenomenon, vortexes develop as the sun sets over the pole and temperatures cool, and occur in the middle and upper troposphere and the stratosphere (roughly, between six and 31 miles above the Earth’s surface).

Where will a polar vortex hit?

In the Northern Hemisphere, the vortexes move in a counterclockwise direction. Typically, they dip down over Canada, but according to NBC News, polar vortexes can move into the contiguous U.S. due to warm weather over Greenland or Alaska—which forces denser cold air south—or other weather patterns.

Polar vortexes aren't rare—in fact, arctic winds do sometimes dip down into the eastern U.S.—but sometimes the sheer size of the area affected is much greater than normal.

How cold is a polar vortex?

So cold that frozen sharks have been known to wash up on Cape Cod beaches. So cold that animal keepers at the Calgary Zoo in Alberta, Canada once decided to bring its group of king penguins indoors for warmth (the species lives on islands north of Antarctica and the birds aren't used to extreme cold.) Even parts of Alabama and other regions in the Deep South have seen single-digit temperatures and wind chills below zero.

But thankfully, this type of arctic freeze doesn't stick around forever: Temperatures will gradually warm up.

In What Field Was Dr. Martin Luther King, Jr. a Doctor?

Express Newspapers/Getty Images
Express Newspapers/Getty Images

Martin Luther King, Jr. earned a doctorate in systematic theology from Boston University in 1955. He’d previously earned a Bachelor of Arts from Morehouse College and a Bachelor of Divinity from Crozer Theological Seminary. His dissertation, “A Comparison of the Conception of God in the Thinking of Paul Tillich and Henry Nelson Wieman,” examined the two religious philosophers’ views of God in comparison to each other, and to King’s own concept of a "knowable and personal" God.

Some three decades after he earned his doctorate, in 1989, archivists working with The Martin Luther King Papers Project discovered that King’s dissertation suffered from what they called a “problematic use of sources.” King, they learned, had taken a large amount of material verbatim from other scholars and sources and used it in his work without full or proper attribution, and sometimes no attribution at all.

In 1991, a Boston University investigatory committee concluded that King had indeed plagiarized parts of his dissertation, but found that it was “impractical to reach, on the available evidence, any conclusions about Dr. King's reasons for failing to attribute some, but not all, of his sources.” That is, it could have been anything from malicious intent to simple forgetfulness—no one can determine for sure today. They did not recommend a posthumous revocation of his degree, but instead suggested that a letter be attached to the dissertation in the university library noting the passages lacked quotations and citations.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

This article was originally published in 2013.

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