Days Postings
July 2025 M T W T F S S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Blog Series
Copyright Notice
© Mark Biegert and Math Encounters, 2024. Publication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Mark Biegert and Math Encounters with appropriate and specific direction to the original content.
Disclaimer
All content provided on the mathscinotes.com blog is for informational purposes only. The owner of this blog makes no representations as to the accuracy or completeness of any information on this site or found by following any link on this site. The owner of mathscinotes.com will not be liable for any errors or omissions in this information nor for the availability of this information. The owner will not be liable for any losses, injuries, or damages from the display or use of this information.
Author Archives: mathscinotes
Epidemiology and Cell Towers
Introduction I received a phone call from a cancer epidemiologist last Friday. He had received my name from a co-worker in his department who knows me. This researcher is in the process of researching a cancer cluster near a cell … Continue reading
Posted in Electronics, Osseo
2 Comments
Neat photos from the International Space Station
Neat photos from the International Space Station Some co-workers and I are practicing speaking German while at work. One of these co-workers found some great photos on the Der Spiegel web site, which is a site we use for practice. … Continue reading
Phone Line Impedance Levels: 600 Ohms and 900 Ohms
Engineering is a pretty conservative profession -- I have been accused of "abhorring change". Once something gets standardized it stays in place even when it does not make sense. This morning provided me a good example of this. Phone lines in the United States are usually characterized as having a characteristic impedance of 600 Ω or 900 Ω. These impedance levels go back to the early days of telephony (Figure 1). However, all the phone cables we work with are Category 3 and therefore have identical characteristic impedance (~725 Ω). So why the different impedance levels? I had a discussion with one of our telephony engineers about it this morning and all we could do is speculate. I thought I would document this speculation here. Continue reading
Posted in Electronics, Telephones
6 Comments
Engineering Application of Conformal Mapping
Introduction I have a project that I am working on that involves the use of conformal mappings. I have long found the use of complex numbers in electrical engineering interesting. My first contact with an engineering application of conformal mappings … Continue reading
Posted in Electronics
4 Comments
Distibution of Catholics Around the World
Introduction I am showing one of my sons how to use Excel pivot tables, so I am looking for good data analysis examples that illustrate the power of pivot tables. The election of a pope has put Catholicism in the … Continue reading
Posted in General Mathematics
Comments Off on Distibution of Catholics Around the World
A World War 1 Mechanical Torpedo Fire Control Computer
I have discussed the basic calculations behind firing "straight-running" torpedoes in other posts (here, here, and here). Youtube has a couple of interesting videos showing a basic mechanical torpedo fire control computer from World War 1. It is a nice … Continue reading
Posted in History of Science and Technology, Underwater
1 Comment
Hometown Humor
My brother called the other night and said that he was going to attend a live show with Kevin Kling, a well-known comedian we grew up with in Osseo, Minnesota. In my youth, Osseo was a small agricultural community on … Continue reading
Spline Interpolation Example Using Battery Capacity
Introduction I had a conversation with a customer recently who wanted to estimate the capacity and running time of their electronic systems when operating from batteries that are under various current load and temperature stresses. The battery manufacture had only … Continue reading
Posted in Batteries, General Mathematics
Comments Off on Spline Interpolation Example Using Battery Capacity
Battery Life Dissipated Under Varying Temperature Conditions
Introduction I am not getting any younger. As I age, I have come to realize that certain activities age me faster than others. For example, I have no doubt that sitting in meetings for hours every day has deleterious effects … Continue reading
Posted in Batteries, Electronics
1 Comment
Asteroid Belt Mass Distribution Analysis
Introduction The meteor explosion over Russia really interests me and I have been reading as much about it as I can. While reading about meteors and asteroids, I encountered the following statement. The total mass of the asteroid belt is … Continue reading
Posted in Astronomy
Comments Off on Asteroid Belt Mass Distribution Analysis