The Spinning Dancer is a popular optical illusion that even has its own wikipedia entry.
The illusion is the following:
The illusion was created by web designer Nobuyuki Kayahara and the question is “Which direction is the dancer spinning?” That is, is the dancer is spinning clockwise or counter-clockwise?
“If the foot touching the ground is perceived to be the left foot, the dancer appears to be spinning clockwise (if seen from above); if it is taken to be the right foot, then she appears to be spinning counterclockwise.”
A nice graphic that illustrates how the dancer can be observed as spinning in either direction is below. By simplying adding some lines to the original image you you can give direction to the dancer. The left image shows the dancer spinning clockwise, while the right image shows the dancer spinning counter-clockwise.
The FBI has released two notes in code that relate to the murder case of Ricky McCormick from 1999. McCormick had been murdered and his body was dumped in a field. The only clues were the two encrypted notes below that were found in the victim’s pockets. Despite several experts working on the code (including linguists, computer scientists and mathematicians) the code has still not been broken.
According to the FBI news story:
“McCormick was a high school dropout, but he was able to read and write and was said to be “street smart.” According to members of his family, McCormick had used such encrypted notes since he was a boy, but apparently no one in his family knows how to decipher the codes, and it’s unknown whether anyone besides McCormick could translate his secret language. Investigators believe the notes in McCormick’s pockets were written up to three days before his death.”
If you know what the notes say, submit your comments to the FBI site here.
Why don’t they make Klein bottles in China?
They’re not orientable.
I don’t like my girlfriend… Mind if I do a you-substitution?
A guy walks into a sandwich shop and sees a sign that reads, “Home of the Meanest Grilled Cheese in Town.” So he orders the grilled cheese. When his bill arrives the waitress asks him how he liked the sandwich. “Eh, it was about average.”
What is int 1/mower d(mower)?
Research has shown that 50% of people in a relationship are dating someone smarter than them.
Following up from his video last year, Matthew Weathers (who
teaches in the Math Department of Biola University) did another video trick for his Nature of Math
If you miss his video last year, you can check it out here: