Probability rules our entire lives, but our brains absolutely suck at calculating it. The gambling industry thrives off of this fact -- tell someone they only have a 1-100,000,000 chance of winning the lottery, and they'll say, "somebody's got to win!"

We can't blame them -- there are all sorts of ways that probability works like freaking black magic. Just try to wrap your mind around the fact that ...

## 6 When You Shuffle A Deck Of Cards, You're Creating A Sequence That Has Never Existed Before

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The Scenario:

Let's say you're the dealer at a casual Friday night poker game. Let's also say, for the sake of argument, that you're an expert shuffler, and not one of those people who just clumsily swirls cards around like an infant. You expertly riffle the cards, toss them hand to hand, juggle them, throw them into a hat, etc., until eventually you're confident that you've fully randomized the cards.

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But be sure to placate the one asshole who insists on cutting the deck.

What are the chances that the configuration of the deck you now hold is the same as one that you've shuffled before on a previous poker night? One chance in 1,000? One in 10,000? We mean, there's only 52 cards, so how many can it really be?

The Reality:

You should feel special, because it's almost certain that the configuration of the deck you hold in your hand has never been held by any human being in the history of mankind, on this Earth, or on any one of its many parallel universes. You currently hold in your hand something that will never again be seen, from now until the end of time itself.

It's true that 52 cards doesn't seem like a lot. But if you try to count the number of possible combinations of those cards, you better have a few evenings free. The total number of statistical combinations of a 52-card deck is what's known as "52 factorial," sometimes referred to as "52!" or "52 shriek." Written out in full, that number is:

80,658,175,170,943,878,571,660,636,856,403,766,975,289,505,440,883,277,824,000,000,000,000

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Fine, matholes. *Maybe* 52! is a *little* easier to write.

That's a giant-ass number. To put into into perspective, it's been calculated that "if every star in our galaxy had a trillion planets, each with a trillion people living on them, and each of these people has a trillion packs of cards and somehow they manage to make unique shuffles 1,000 times per second, and they'd been doing that since the Big Bang, they'd only just now be starting to repeat shuffles."

If that hurts your brain, think of it this way: There are only 52 cards, but there are only half that many letters in the English alphabet. Think about all of the different books that have been written just by mixing those same letters around. There has to be like, dozens.

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But only a couple that *really* matter.

## 5 Pi Can Be Calculated By Randomly Dropping A Bunch Of Paper Clips

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The Scenario:

Let's play a quick game. All it takes is a piece of paper, a pencil, and a handful of paper clips (or needles, or nails, anything like that).

Draw two parallel lines on the paper, approximately two paper clip lengths apart. Now go ahead and drop a handful of paper clips on the space between the lines. It doesn't matter how many paper clips you use, but the more the better, so feel free to go hog wild.

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And if you can tell how many are on the paper just by looking, stop reading and get your ass to Vegas.

Take the total number of paper clips, multiply it by two, then divide that number by the number of needles that are touching one of the lines. So if you drop 20 paper clips, 13 of them are laying across one of the lines, you'd divide 40 by 13. The number you wind up with will be close to pi ... and if you up the number of paper clips, it will get closer and closer.

Like, sorcery close.

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Which led to the lesser-known Salem nerd trials of colonial times.

The Reality:

Yeah, pi is one of those mysterious things that just keeps popping up in the universe, like Q from *Star Trek*. In this case, assuming that the position of the paper clips you dropped is completely random, all of their angles and locations will tend to even out. In much the same way that coin flips will tend to even out toward an equal number of heads and tails, even though each individual flip result is random.

Like coin flips, the result gets more accurate the more you do it, as sheer persistence irons out statistical aberrations. While your coin flips get closer to 50-50 the more times you flip, your paper clips get closer to pi the more times you drop. If you don't have the time or the paper clips to do it yourself, there are online simulations that will do it for you, because of course there are.

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"Hey Mom ... yeah, they have me doing a really important project at work."

The exercise is so accurate that it's one of the methods supercomputers use to calculate pi to the billions of decimal places, which is a surprise, considering we really thought supercomputers would do actual math instead of throwing virtual office supplies all over the place.

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