Is anyone familiar with an Euler's Disk? (physics, conservation of energy and angular momentum demonstration).

At this one site I haunt now and then, looking for new science toys and things to hack, I came across this little item called a Euler's Disk.  I am assuming at this point, that there is quite a bit of specificity in the way this needs to be made so that it works, thus the $25 price tag. Anyone have any information (not contained in the ad) on this?   It'd be most appreciated.  

Posted by Goodhart 8 years ago


When Zombies Attack!

From the University of Ottowa:A mathematical modeling of an outbreak of Zombie infectionWith citations, graphs and MATLAB code.As seen in the movies, it is imperative that zombies are dealt with quickly, or else we are in a great deal of trouble.

Posted by lemonie 9 years ago


Fun Facts about Pi Day

The Pi Day Pie Contest is open until March 31st. Share a pie recipe to win a stand mixer. There's even a special judge's prize for the best pi-themed decoration. This year's Pi Day is special, because it's Pi Day ALL MONTH LONG. The third month of the fourteenth year (3/14) lasts for the duration of March, and it won't happen again for another hundred years. So get baking! Some miscellaneous Pi facts: (1) Pi is the ratio of a circle’s circumference to its diameter. Pie is a baked dish made of sweet or savory filling wrapped in pastry dough. They are often, but not always, circular. Expressed in terms of pie, π is the ratio of the diameter of the pan to the length of the crust. (2) Pi didn’t always have a name, much less a sweet Greek letter of its own. Contemporary use of the π symbol is thanks to mathematician William Jones, who in 1706 proposed using the letter p to indicate perimeter. Leonhard Euler, the same guy who brought you functional notation in the form of f(x), popularized π by including it in his work around 1737. Euler is responsible for many of the letters that bedevil beginning algebra students: i for the square root of -1, e for the base of the natural logarithm, and much of the notation for trigonometric functions. There is a Wikipedia page devoted to the list of things named after him, and it is enough to make an English major blanche in terror. (3) Pi Day is officially a thing, at least in the United States. In 2009, House Resolution 224 officially recognized Pi Day as a holiday on March 14th. Presumably as a kick in the pants for the education system, not as a literal example of political pork. Resolved, That the House of Representatives-- (1) supports the designation of a `Pi Day' and its celebration around the world; (2) recognizes the continuing importance of National Science Foundation's math and science education programs; and (3) encourages schools and educators to observe the day with appropriate activities that teach students about Pi and engage them about the study of mathematics. (4) Pi is vaguely described in 1 Kings 7:23-26 in the King James version of the Bible. Solomon's pool should probably have been 31.4 cubits around, but he deserves some credit for getting pretty dang close. (5) Pie Day is on January 23rd, according to the American Pie Council, but they're still cool with celebrating Pi Day with pies.

Posted by wilgubeast 4 years ago