What’s the difference between a PhD in math and a large pizza?
My friend just finished a job interview and was asked the following question that I thought I’d share with you (it’s a somewhat common puzzle):
You are given 8 balls, 7 of which are the same weight and 1 which is heavier than the rest. Using a balance, what is the minimum number of weightings required to determine which ball is the heavier one?
A couple of University of Pennsylvania mathematicians found solutions to some 140-year-old 7-dimensional equation. I guess solutions were not known to exist for
more than a century despite it being very popular in modeling the behavior
The solution was found by Philip Gressman and Robert Strain and published in the Proceedings of the National Academy of Sciences. Strain says:
“We consider it remarkable that this equation, derived by Boltzmann and
Maxwell in 1867 and 1872, grants a fundamental example where a range of
geometric fractional derivatives occur in a physical model of the
natural world… The mathematical techniques needed to
study such phenomena were only developed in the modern era.”
Yay for math!
This was posted by gayandgeishaandguido.tumblr.com with the phrase:
WHY AM I SO UNBEARABLY FUNNY
I get the straight and bisectual, but why is there a circle for gay? Help!!
Saw this on Terry Tao’s blog, it’s a drinking game suggested by Mark Schnitzius that can promote mathematical thinking. Mark says:
“I was watching a travel show a while back — they were in Korea, and a group of people were playing a drinking game. The way it worked was, one person was “it”. This person says something like, “ready, set…” then points at one other player and calls out a number (call it x) between 2 and n (where n is the number of people playing). At the same time, everyone else also points at one other player. Then, for whatever number got call out, you jump that many steps from the “it” person, and that person has to drink. So if I call out “two” and point at Joe, and Joe points at Bob, then Bob has to drink.
I think the game is pretty interesting, mathematically, and could easily be adapted to be a game for kids. It’s especially interesting when you relax the x<=n rule. One interesting thing I found: with n=3, if you call x=7, you are guaranteed to stick the player you initially point at, no matter who points to whom.
Some interesting questions to ponder about it:
- Without the x<=n rule, what is the smallest number the ‘it’ person can call that guarantees he will not stick himself?
- With the x<=n rule in place, what is the safest number to call for any given n, if the other players choose randomly?
- If you’re TRYING to lose, what number should you call, both with and without the x<=n rule?
- What are the odds of winning or losing, for all the answers above?
Hint for questions 1 and 2: prime numbers come in to play!”
Another silly drinking game is below:
Here is an old music video for Johnathan Coultan’s song Mandelbrot Set (this is by Pisut Wisessing that was made in Film class at the Cornell Summer Animation Workshop). Enjoy!
Today’s Spiked Math comic is:
The joke lies in combining the Banach-Tarski paradox with a miracle that Jesus performed:
1. The Banach-Tarski paradox is a theorem that basically says a solid ball (in 3-dimensions) can be split into a finite number of non-overlapping pieces, which can then be put back together in a different way to yield TWO identical copies of the original ball. It doesn’t work in 1 or 2-dimensions though. Wikipedia has a great picture of this:
2. One of the miracles of Jesus was feeding the multitude. Basically the story has Jesus taking five (or seven) loaves and two fish and feeding thousands of people. Jesus took the five loaves and the two fish and looking up to heaven, “he gave thanks and broke the loaves. Then he gave them to the disciples, and the disciples gave them to the people. They all ate and were satisfied, and the disciples picked up twelve basketfuls of broken pieces that were left over. The number of those who ate was about five thousand men, besides women and children.”