Merry Math Christmas

Yes, the math checks out.

'Tis the Season

Happy Halloween

Donut or Coffee Cup?

Great tweet from Vincent Pantaloni: If you're a topologist (Helvetica font style) there are 8 (capital) letters in the English alphabet.

When mathematicians get hungry

While we are talking math...

Note - the real Fibonacci number image would be:

The best way to get girls

NFL player John Urschel, seeking Ph.D. in math, retires from football at age 26.

There is only one explanation: he did it for the babes. 

Chinese Tangram Puzzle

Mathematician Dan Hanson spoke at the ClevelandPeople.Com Food Adventure to The Pearl Asian Kitchen.  The Food Adventurers travel to authentic ethnic restaurants in the Cleveland area and, besides enjoying a special traditional menu, learn about the culture of the country.

Dan told about and demonstrated the popular Chinese Tangram Puzzle whcih was as popular as the Rubik's Cube when it came out.

Cleveland Chinese community

Great Lakes Geek Science and Math



Here is a duck made of the 7 Tangram puzzle pieces

Chinese Math and the Abacus

Mathematician Dan Hanson spoke at the ClevelandPeople.Com Food Adventure to The Pearl Asian Kitchen.  The Food Adventurers travel to authentic ethnic restaurants in the Cleveland area and, besides enjoying a special traditional menu, learn about the culture of the country.

Dan told some basics about Chinese mathematics and the Chinese abacus which is able to do hexadecimal calculation as opposed to abacuses from other countries.


Cleveland Chinese community

Great Lakes Geek Math and Science

 

Statistics Done Wrong - Book Review

Author Alex Reinhart's s bio says "I’m a PhD student in statistics at Carnegie Mellon University, after previously earning my BSc in physics at the University of Texas at Austin while doing research on statistical methods to detect unexpected radioactive sources using mobile detectors. (I preferred to call it “finding radioactive people at football games.”) I now work on statistical models to understand and predict where crimes occur."

He obviously know his stuff - it just wasn't the stuff that I expected when I picked up the book.

As a mathematician I like to read books on various math disciplines especially topology, set theory and so on but also some applied topics such as probability and stats. I wrongly assumed that Statistics Gone Wrong would be about how methods and theorems of applied stats can lead to inaccurate results. The book is more for people who analyze data and make statistical predictions.

Don't get me wrong. The author does a very complete job in demonstrating how using stats can lead to inaccurate and even false conclusions. He starts with defining p values and gives examples of how they can lead to inaccuracies.

The use of examples is interesting such as the published results of the "Right turn on Red" data.

The author writes "If you’re a practicing scientist, you probably use statistics to analyze your data. From basic t tests and standard error calculations to Cox proportional hazards models and propensity score matching, we rely on statistics to give answers to scientific problems. This is unfortunate, because statistical errors are rife.

Statistics Done Wrong is a guide to the most popular statistical errors and slip-ups committed by scientists every day, in the lab and in peer-reviewed journals. Many of the errors are prevalent in vast swaths of the published literature, casting doubt on the findings of thousands of papers. Statistics Done Wrong assumes no prior knowledge of statistics, so you can read it before your first statistics course or after thirty years of scientific practice."

It's a good, solid book. Just don't expect it to be about probability and statistics. It is about the errors that can be made in analyzing data.

The answer is... Simple Math Trick

Here's a very basic math exercise that won't amaze your friends but will get them thinking. I like to pretend I am opening an envelope a la Johnny Carson's Carnac or have the answer written on my arm or something.


Pick a three digit number of different numbers (so 123 or 487 are OK but 111 or 232 are not) Let's use 816 as an example.

Reverse the number. So 816 becomes 618

Subtract the smaller number from the larger. 816-618=198

Reverse the answer number. 198 becomes 891

Add that number to the answer of the subtraction. 891 + 198 = 1089

Voila! The result is 1089!

It's simple to prove with a little Algebra - Let the Geek know if you can't figure it out. It's based on the places of the digits so if you choose a number like 546 the process will be 645-546=99 and 99+99=198 not 1089.

You have to look at it like 99 is really 099. So 990-099=891 and 891+198=1089

Note also that it may not work with repeated digits because if it's a palindrome like 575 when you reverse it you will also get 575 and the difference will be 575-575=0 so there is nothing to work with.

History of Zero and Arab contributions to Math

Great Lakes Geek Dan Hanson was at a Cleveland Food Adventurers event at Kan Zaman Middle Eastern Restaurant when the conversation steered toward math and science.

He was asked to tell the group a little about Arab contributions to Math and this video snippet is the result.

Happy Pi Day

We all know that Pi is the mathematical constant that is the ratio of the circumference of a circle to it's diameter.  Pi is irrational and its decimal representation goes on forever and never settles into a repeating pattern.

Of course, Pi begins with 3.14159... so March 14 or 3-14 is celebrated as Pi Day.