This math argument just doesn’t add up

There’s a reason why this video pissed me off, but I’m not a math scholar and couldn’t explain it. Just the basic premise that if you add all positive numbers beginning with one, you’ll get a negative number is absurd.

The answer is infinity. Has to be. What bothered me is the guy pulled a trick by immediately going from 1+2+3+4+5+ …. = -1/12, and saying:

Rather than use these … let’s just think of this series.

No! Stop! That’s intentionally deceptive. If you’re making a case that 1+2+3+4+5+… = -1/12, use the numbers! Don’t use symbols. Using a different series is a red herring!

Well, that’s what I want to say. But as I said earlier, I’m not a math scholar, so I don’t have any defense for my argument because I don’t have the expertise.

Thank goodness for Mathbabe:

I’m not going to just vent about the cultural context, though, I’m going to mention what the actual mathematical object of study was in this video. Namely, it’s an argument that “prove” that we have the following identity:

“1 + 2 + 3 + 4 + … = -1/12.”

Wait, how can that be? Isn’t the left hand side positive and the right hand side negative?!

This mathematical argument is familiar to me – in fact it is very much along the lines of stuff we sometimes cover at the math summer program HCSSiM I teach at sometimes (see my notes from 2012 here). But in the case of HCSSiM, we do it quite differently. Specifically, we use it as a demonstration of flawed mathematical thinking. Then we take note and make sure we’re more careful in the future.

I feel better. Read Cathy O’Neal’s (Mathbabe’s) post here for the full counterargument. The headline: If it’s hocus pocus then it’s not math.

Facebook and too much information

One thing I’ve noticed in the news for a while is that when anyone does anything particularly weird, crazy or murderous, some reporter somewhere finds that person’s Facebook profile and gets all kinds of juicy details.

Because a lot of people spell out their whole lives on Facebook.

There’s even an insurance commercial that talks about how burglars use Facebook to determine when someone is leaving their house vacant for a significant amount of time:

And the thing about Facebook is that it seems to be impossible to remove things from it. Back in the days when I had to hire people for a living, I’d occasionally do a Google search on them and find their life histories on their Facebook pages. (Yeah, dude, that photo of you with no shirt on and in the hat that holds two beer cans that have straws leading to your mouth is really going to impress your future employer.) I tell younger family members to watch what they post.

So wouldn’t it be nice to have the ability to erase your Facebook profile? (From Slate):

facebook_delete

Wow. That seems like a lot of work!

The grinch who stole “The Price Is Right”

This is supposed to be a happy game-show story:

It was on “The Price Is Right” yesterday. The winner is a woman named Sheree, who’s from Washington. Her wish was to win a big prize. She did. An Audi worth almost $160,000 and $10,000 in cash.

Should I break it to her that she’s not going to keep the car? I mean, she looks so happy.

I’m just going with the odds here. I was on a game show once. Won a significant chunk of money and a trip to Europe. I also had to pay taxes on the winnings. Federal tax, taxes to the state I lived in, and California taxes, because that’s where the show was taped.

Now, for argument’s sake, I’m guessing the taxes all together are going to be AT THE VERY LEAST 30 percent of the total, so somewhere in the vicinity of $60,000.

She doesn’t have that kind of money. She said so. Remember when she turned over the first card and got $4,000, and she yelled to her significant other in the audience, “$4,000 is a lot of money.” Yes, when you don’t have a lot of money, $4,000 is a lot of money.

And $60,000 is a lot more money. I’m not going out on a limb here when I say she doesn’t have $60,000 laying around to pay the taxes on $170,000. The $10,000 in cash she won isn’t going to cover it.

So, she won’t keep the car. She’ll probably turn it over to an Audi dealer, who will take it off her hands for far less than the retail price, because as an owner, she now makes it a used car (pre-owned as they say in the classy television ads). And I’m not a tax lawyer here, but she still did get $170,000 from “The Price Is Right.” That’s income. Income is taxed. She still owes about $60,000. All told, she might walk away with cash in the low five figures. But nowhere near this “Price Is Right” moment. Maybe “The Price Is Right” folks have this all figured out and they’ll offer her a cash deal that covers everything. I doubt it, though.

I guess this dose of reality makes me the grinch who stole “The Price Is Right.” But I didn’t steal it. The tax man did. And the folks on “The Price Is Right” know this is going to happen. They also know this is great television. That means higher ratings. That means they can charge more for ads. You know, like giving Audi this six-minute ad for a car that’s never going to go to the contestant who won it.

Oh, you thought Audi gave “The Price Is Right” the car, or the show bought the car from Audi? No, this is product placement. The car will be back in the showroom next week. No cost to Audi. No cost to “The Price Is Right.” A $60,000 cost for the poor lady who’s having the happiest moment of her life.

(By the way, I did pay the taxes on my game-show winnings. Spent Easter in the sun in southwestern Europe. It was very nice.)