Slide Rule Collection Donated to Illinois Tech

Today, I received notice from the Library at the Illinois Institute of Technology that the slide rule collection I donated to the school is now on display. Over forty years ago, I started collecting slide rules and over the years, the collection grew to over thirty items. Earlier this year, I donated the collection to Illinois Tech, where I earned my Bachelor of Science degree in Materials Science and Engineering.

The collection also includes books of logarithmic and trigonometric values.

Some photos of the library display are shown below:

(photos by: Matt David, Director, Advancement Special Projects, IIT)

Other posts on slide rules: 

Math Vacation: 2022 Anniversaries (jamesmacmath.blogspot.com)

Math Vacation: Benford Distribution - Additional Thoughts (jamesmacmath.blogspot.com)

 

Anniversary of Euler's death

(Image: Jakob Emanuel Handmann - Kunstmuseum Basel, Public Domain)

Yesterday, September 18, 2023, was the 240th anniversary of the death of the Swiss mathematician Leonhard Euler. He was born in 1707 in Basel, Switzerland.

A more complete description of his life was recently published by Breakpoint Colson Center: Leonhard Euler: Called to Mathematics - Breakpoint (Includes an audio version).

Other posts in this blog related to Euler:

Math Vacation: Euler's Identity (jamesmacmath.blogspot.com)

(More on Euler’s Identity: Euler's identity - Wikipedia)

Math Vacation: Euler Characteristic of Polyhedra (jamesmacmath.blogspot.com)

Math Vacation: Project Euler (jamesmacmath.blogspot.com)

Math Vacation: Using Random Numbers to Estimate Pi (jamesmacmath.blogspot.com)

Math Vacation: Perfect Number Generator (jamesmacmath.blogspot.com)

More on Euler: Leonhard Euler - Wikipedia

 

 

Rosh Hashanah 5784

(Image: Iconfinder - ByteDance IconPark (oceanengine.com))

Last night (September 15, 2023) at sunset began Rosh Hashanah, beginning the new year 5784 in the Jewish Calendar. The Jewish calendar is the oldest calendar still in use today. It was started in the 9th century BC and based on biblical calculations that the creation took place in 3761 BC. 

Cinquante Signes

Éric ANGELINI writes the blog, Cinquante signes and is a frequent contributor to the Online Encyclopedia of Integer Sequences (OEIS). His blog provides further information on his sequences along with good graphics that illustrate the sequences.

A364831 and A364589: New Sequences Published in the Online Encyclopedia of Integer Sequences

I recently had two additional sequences published in the Online Encyclopedia of Integer Sequences.

A365589 - OEIS, numbers that have at least one prime digit and at least one nonprime digit and

A364831 - OEIS, primes whose digits are prime and in nonincreasing order.

In 1964 Neil Sloane started the maintenance of a list of integer sequences. Once his collection grew, he published the list in a book in 1973 ("A Handbook of Integer Sequences", by NJAS, Academic Press, NY). This book contained 2372 sequences.

Since 1996. the list in the form of a database has been maintained on the internet. As of the date of this post, it has over 300,000 different sequences that can be searched in many different ways. The formal name is The On-Line Encyclopedia of Integer Sequences or OEIS. This is a link to the database.

To view any of the sequences that I've authored or to which I have contributed, see: james c. mcmahon - OEIS.

An Open Message to the Blog's Fans in Singapore

(Image: Free 12 singapore icons - Iconfinder)

This past week, more views of this blog were made from Singapore than other country. To acknowledge these viewings, I wanted to write a post about Singaporean mathematicians. After a search, I found the following link on Wikipedia: Category:Singaporean mathematicians - Wikipedia. I'm asking my readers to add a comment to the blog in order to supplement this Wikipedia entry. For example, of these eleven mathematicians, are there a few who really stand out? Are there any people who should be added to the list? Thank you for your contributions!

• Louis Chen Hsiao Yun
• Chong Chi Tat

• Lam Lay Yong
• Peng Yee Lee
• Lek-Heng Lim

• Peng Tsu Ann

• Sun Yeneng

• Tan Eng Chye
• Tony Tan
• Kim-Chuan Toh

• Chen-Bo Zhu

10,000

My math blog just crossed over 10,000 views as of September 3, 2023, so I decided to write some interesting facts about 10,000.

Minnesota, also known as The Land of 10,000 Lakes, actually has 11,842 lakes.

For exercise, many people try to get in 10,000 steps in a day. That's approximately 5 miles or 8 kilometers.

Salmon P. Chase is featured on the U.S. $10,000 note.

There is a "$10,000 rule" which requires banks to report deposits or withdrawals of $10,000 or more of cash.

In English, myriad is used to describe a large number or a countless number of objects. The term is from the ancient Greek word for 10,000, myrias (μυριάς).

Update, 9/29/2023 - a $10,000 note recently sold for $480,000. Link to article.