Skip to main content

Wha?! 1+2+3...+N = -1/12

Update: People who know math deeply (i.e. not me) hate this video. Those people have spoken, loudly. Thx math people! Side note: Summing the number of planets in the Galaxy will never yield -1/12, so my research is safe...

Via Phil Plait on Slate.com, a little bit of mathematical hokus pokus:


Comments

EB said…
It's good for readers to see the follow up post by Phil Plait, as well as some other critiques offering more nuance to this video. It is slightly misleading now, particularly the "proof" and the ending discussion. See http://bit.ly/KCq4xG

In any sense, this result needs serious qualification. In a nutshell, 1-1+1-1+1-1+.... is not convergent, and you therefore need to discuss analytic continuation and the Riemann zeta function.

Ed Copeland offers more details in the longer video here: https://www.youtube.com/watch?v=E-d9mgo8FGk&feature=youtu.be

It's slightly disappointing how this material is presented here, which is surprising, as usually Brady Haran's stuff with the faculty at Nottingham is so good. This video seems to push the "Math is cray and totz weird!!!1!" notion without providing vital caveats and explanations.

Popular posts from this blog

On the Height of J.J. Barea

Dallas Mavericks point guard J.J. Barea standing between two very tall people (from: Picassa user photoasisphoto).

Congrats to the Dallas Mavericks, who beat the Miami Heat tonight in game six to win the NBA championship.

Okay, with that out of the way, just how tall is the busy-footed Maverick point guard J.J. Barea? He's listed as 6-foot on NBA.com, but no one, not even the sports casters, believes that he can possibly be that tall. He looks like a super-fast Hobbit out there. But could that just be relative scaling, with him standing next to a bunch of extremely tall people? People on Yahoo! Answers think so---I know because I've been Google searching "J.J. Barea Height" for the past 15 minutes.

So I decided to find a photo and settle the issue once and for all.

I started by downloading a stock photo of J.J. from NBA.com, which I then loaded into OpenOffice Draw:


I then used the basketball as my metric. Wikipedia states that an NBA basketball is 29.5 inches in circumfe…

Finding Blissful Clarity by Tuning Out

It's been a minute since I've posted here. My last post was back in April, so it has actually been something like 193,000 minutes, but I like how the kids say "it's been a minute," so I'll stick with that.
As I've said before, I use this space to work out the truths in my life. Writing is a valuable way of taking the non-linear jumble of thoughts in my head and linearizing them by putting them down on the page. In short, writing helps me figure things out. However, logical thinking is not the only way of knowing the world. Another way is to recognize, listen to, and trust one's emotions. Yes, emotions are important for figuring things out.
Back in April, when I last posted here, my emotions were largely characterized by fear, sadness, anger, frustration, confusion and despair. I say largely, because this is what I was feeling on large scales; the world outside of my immediate influence. On smaller scales, where my wife, children and friends reside, I…

The Force is strong with this one...

Last night we were reviewing multiplication tables with Owen. The family fired off doublets of numbers and Owen confidently multiplied away. In the middle of the review Owen stopped and said, "I noticed something. 2 times 2 is 4. If you subtract 1 it's 3. That's equal to taking 2 and adding 1, and then taking 2 and subtracting 1, and multiplying. So 1 times 3 is 2 times 2 minus 1."

I have to admit, that I didn't quite get it at first. I asked him to repeat with another number and he did with six: "6 times 6 is 36. 36 minus 1 is 35. That's the same as 6-1 times 6+1, which is 35."

Ummmmm....wait. Huh? Lemme see...oh. OH! WOW! Owen figured out

\begin{equation}
x^2 - 1 = (x - 1) (x +1)
\end{equation}

So $6 \times 8 = 7 \times 7 - 1 = (7-1) (7+1) = 48$. That's actually pretty handy!

You can see it in the image above. Look at the elements perpendicular to the diagonal. There's 48 bracketing 49, 35 bracketing 36, etc... After a bit more thought we…