## Posts tagged ‘Chanukah’

### Dreidel is Not Fair

play an online version of dreidel at the Jewish Outreach Institute (but turn the sound off)

Is dreidel fair?

The rules of dreidel are straightforward. At the beginning of each round, players put one coin into the pot. (For young kids, the “coins” are actually chocolate pieces in the shape of a coin and wrapped in gold foil. This is known as geld, and as far as I’m concerned, chocolate is a currency to kids.) Players then take turns spinning the dreidel, and a reward is earned based on which of the four Hebrew letters appears on top when the dreidel stops spinning:

• Nun: nothing.
• Hey: half the pot.
• Gimel: all of the pot.
• Shin: put one in.

Play continues clockwise, with each person spinning the dreidel until Gimel occurs and all coins are removed from the pot. At that point, everyone antes another coin, and a new round starts with the next player.

Officially, a player is out of the game when she or he has no coins left to contribute to the pot, and the game ends when one person has all the coins. But practically speaking, the game often ends much earlier, because players get bored and quit or, in the case of very young kids, the game lasts beyond bedtime and the children are pulled away by their parents.

No matter how the game ends, though, it’s not fair.

The following table is courtesy of Paul J. Nahin (Will You Be Alive 10 Years from Now?, Princeton University Press, 2014, p. 81). It shows the amount, over the long run, that each player will win during a dreidel game.

 Player 1 2 3 4 5 Number of Players 2 1.143 0.857 3 1.361 0.956 0.680 4 1.617 1.102 0.757 0.524 5 1.900 1.267 0.855 0.580 0.398

In other words, the first player has a significant advantage over the others. In a game of five players who start with 10 coins each, the first player will finish the game with 19 coins, on average, whereas the fifth player will finish with just 4 coins. That’s if the game ends early. If played until one person gets all the coins, then the first player is five times more likely to win than the fifth player.

This disparity in odds is likely the reason that an unofficial rule of dreidel is that the youngest player goes first, the second-youngest player goes second, and so on.

The word dreidel is Yiddish and means “to turn around.” Because the dreidel is, after all, a top.

This fact is not lost on comedian Lewis Black, who has some thoughts on the matter.

Happy Chanukah!

### The Math of Thanksgivukkah

I know it’s rare that Hanukkah and Thanksgiving coincide. But if one more person tells me that it’ll be another 70,000 years before this happens again, I’m gonna scream.

This may be the single dumbest statistic I’ve ever heard. Here’s why.

Consider some of the reasons that cause Hanukkah and Thanksgiving to coincide this year.

• Jews rely on the Shmuelian calendar for religious holidays, which is why Hanukkah seems to vary so greatly from year to year. It wouldn’t appear to vary quite so much if you followed the Shmuelian calendar, but if you’re like most of the world, you rely on the Gregorian calendar. (On the Shmuelian calendar, by contrast, it would seem that Thanksgiving varies a lot from year to year. For instance, Thanksgiving this year occurs on 25 Kislev, next year on 5 Kislev, in 2015 on 14 Kislev, and in 2016 on 23 Cheshvan.)
• The Shmuelian calendar has a 19-year cycle, while the Gregorian calendar has a (roughly) 7-year cycle. So you might expect that the calendars would coincide about every 133 years. And they sort of do. However, the last time that the first day of Hanukkah fell on November 28 was in 1861, two years before Abraham Lincoln declared Thanksgiving an official U.S. holiday in 1863.
• One year on Earth is approximately 365.25 days — but not exactly. In fact, it’s closer to 365.2422 days. That slight difference is about 11 minutes. Not a big deal, really, but over 400 years, the calendar would incur a discrepancy of about three days. That’s why Pope Gregory, in 1582, decreed that years divisible by 100 but not divisible by 400 would not be leap years. But Rav Shmuel, who organized his calendar in the first century, didn’t have access to such specific solar measurements, so the Shmuelian calendar does not make similar accommodations.

Put all that together and — voila! — an amazing coincidence.

Because the Shmuelian calendar gains one day on the Gregorian calendar every 165 years or so — see the third bullet point above — it’ll be tens of thousands of years before they coincide again.

But here’s the thing. It’ll never happen. Not a chance.

There are lots of reasons why not.

First, Thanksgiving has been around for 150 years, but there’s no reason to think it’ll last another 70,000 years any more than the Romans should have thought we’d still be celebrating Saturnalia today. Countries and empires come and go, and so do their traditions.

Second, smart money says that when the Shmuelian calendar gets far enough out of whack that Passover no longer occurs in spring, there will be an adjustment. Or maybe there’ll be an adjustment to the Gregorian calendar first, for as yet unknown reasons. Or perhaps an entirely new calendar will appear on the scene. Who knows?

Third, zombies. Just sayin’.

Dr. Joel Hoffman gives a more detailed and eloquent description of Why Hanukkah and Thanksgiving Will Never Again Coincide over at Huffington Post.

co·in·cide
verb
1.  what you should do when it starts to rain

Speaking of things that coincide…

Parallel lines meet at infinity — which must make infinity a very noisy place!

An unfortunate coincidence…

The grad student stood up in his cubicle and shouted, “Why do things that happen to dumb people keep happening to me?”

And a funny coincidence…

After a long day of teaching, grading papers, and doing research for a paper, a mathematician headed to the pub where he was supposed to meet his wife. Seeing her across the bar, he walked up behind her, spun her stool around, and kissed her on the lips. She pushed him away violently, at which point he realized the woman wasn’t his wife.

“I’m very sorry,” he said. “I thought you were my wife. You look exactly like her.”

“You rotten, good-for-nothing son-of-a-bitch,” she said, and slapped him across the face.

“Funny,” he said. “You talk like her, too.”

### The Twelve Days of Crisp Math – Day 1

Lots of religions and cultures celebrate holidays at this time of year, and most of them last more than just one day.

• Diwali (Hindu)  — 5 days
• Kwanzaa (African-American) — 7 days
• Chanukah (Judaism) — 8 days
• Las Posadas (Latino) — 9 days
• Christmas (Christianity) — 12 days

And while Ramadan isn’t always celebrated in December (it varies quite a bit in the Gregorian calendar; in 2012, it occurred during July and August), it just feels wrong to exclude 23% of the world’s population from this discussion.

• Ramadan (Muslim) — 30 days

Though each holiday lasts a different number of days, on average they last about 12 days:

$\frac{5 + 7 + 8 + 9 + 12 + 30}{6} = \frac{71}{6} = 11.8\overline{3}$

With that in mind, I’ll be posting one math joke a day for the next twelve days to celebrate The Twelve Days of Crisp Math. Consider it my holiday treat to you. And what better date to start than 12/12/12? Just to keep with the theme, today’s joke was posted at 12:12 a.m. (Eastern Time), and each joke during the celebration will be posted at the same time every day.

Granted, math isn’t a religion, but lots of folks treat it like one. In fact, many mathematicians think that they are gods…

Ecologists think they’re biologists;
Biologists think they’re organic chemists;
Organic chemists think they’re physicists;
Physicists think they’re God; and,
God thinks he’s a mathematician.

…or vice versa, I suppose.

Without further adieu, here is the joke for the First Day of Crisp Math.

The failing math student went to the professor’s office to get some help. When he arrived, several students were ahead of him, so he waited patiently for his turn. When he finally went in, he asked his question, and the professor spent the better part of an hour trying various explanations, but nothing worked. The student was clearly frustrated.

“Well,” said the professor. “I suppose after you graduate, you’ll be waiting for me to die so you can spit on my grave.”

“Oh, no,” said the student. “After I graduate, I ain’t never gonna stand in line again!”

The Math Jokes 4 Mathy Folks blog is an online extension to the book Math Jokes 4 Mathy Folks. The blog contains jokes submitted by readers, new jokes discovered by the author, details about speaking appearances and workshops, and other random bits of information that might be interesting to the strange folks who like math jokes.

## MJ4MF (offline version)

Math Jokes 4 Mathy Folks is available from Amazon, Borders, Barnes & Noble, NCTM, Robert D. Reed Publishers, and other purveyors of exceptional literature.