Author Archives: mathscinotes

Futurama Quote on Largest Buggalo Ranch on Mars

Posted on 27-January-2017 by mathscinotes

I am a big fan of Futurama – its going off the air was as disappointing for me as discovering Firefly a few years ago and having only 14 episodes to watch. I love the fact Futurama often includes small bits of real math and science in its scripts. My all time favorite piece of math includes a blackboard showing an actual proof using group theory by Sweet Clyde in the episode "The Prisoner of Brenda." Continue reading →

Posted in Humor | 2 Comments

Effect of Earth's Curvature on Suspension Bridge Dimensions

Posted on 25-January-2017 by mathscinotes

I have received a number of questions recently on how the curvature of the Earth affects building construction. In general, the effects of the Earth's curvature are ignorable because most man-made construction is on too small of a scale to notice the effects of the Earth's curvature. One well documented exception is the Verrazano-Narrows bridge, whose design took into account that the bridge towers are 1 5/8 inch farther apart at the top than at the bottom. In this post, I will show how to compute this value. Continue reading →

Posted in Construction, General Science | 28 Comments

Larsen Ice Shelf and Potential Sea Level Rise

Posted on 23-January-2017 by mathscinotes

I just read an article about a large iceberg that will likely form in 2017 when a 5,000 km2 section of the Larsen C ice shelf (Figure 1) calves into the Antarctic Ocean. There is concern that the formation of this iceberg will remove a barrier that has been preventing the entire Larsen C ice shelf, with a total area of over 50,000 km2, from sliding into the sea. This is a massive amount of ice. Continue reading →

Posted in General Science, News Fact Checking | 2 Comments

Engineers Say the Darndest Things

Posted on 20-January-2017 by mathscinotes

When the humor comes from engineers, it is usually pretty dry. In our office, we keep a whiteboard that is filled with some of the choicest quotes from engineers. I thought I would share a few of them with you. In general, engineers do not want to see their names on the whiteboard because some of the statements are pretty lame. Continue reading →

Posted in Humor | 1 Comment

Temperature Sensing with a Bandgap Reference

Posted on 18-January-2017 by mathscinotes

I have decided that my next home electronics project will be a precision thermometer that I can read over the Internet. I will be mounting the sensor at my cabin in Northern Minnesota, where winter temperatures can drop to -40 °C or lower. During the summer, temperatures can rise to nearly 40 °C. My plan is to connect the unit to a Raspberry Pie that I use to provide remote monitoring and control. I decided that I going to use a Texas Instruments' LMT70 precision temperature sensor, which uses a well-known circuit called a Brokaw bandgap reference to measure the temperature of its die. Continue reading →

Posted in Electronics | 2 Comments

Some PT Boat Statistics

Posted on 16-January-2017 by mathscinotes

I was doing some reading about President John F. Kennedy (JFK) and was surprised to learn that he actually commanded three PT boats: PT-101, PT-109, and PT-59. His service on PT-101 was very short. His next command, PT-109, became famous because of its ramming and sinking by the Japanese destroyer Amagiri. Continue reading →

Posted in History Through Spreadsheets, Military History | Comments Off on Some PT Boat Statistics

Fact Checking Power Over Ethernet Marketing Math

Posted on 10-January-2017 by mathscinotes

I was reading a blog by a cable manufacturer (Belden) this morning on the advantages of using Cat 6 cable over Cat 5e for network installations going forward (Figure 1 shows a great example of network cabling). Normally, I see the cable manufacturers recommending Cat 6 to customers because it will allow them to upgrade to 10 Gbps Ethernet, at least for runs less than 55 meters long. Continue reading →

Posted in Networking | Comments Off on Fact Checking Power Over Ethernet Marketing Math

Good Example of Learning Curve Labor Cost Reductions

Posted on 6-January-2017 by mathscinotes

I am always looking for examples of efficiencies that can be attributed to learning curve and production volumes. Figure 1 shows an example from an analysis of war production in Germany during WW2. This particular example focuses on the labor required to build a Ju 88 multi-role aircraft. Continue reading →

Posted in Management, Product Cost | 1 Comment

Measuring a Chamfer Angle Using Gage Balls

Posted on 5-January-2017 by mathscinotes

One metrology operation I have had to perform a number of times is measuring a chamfer angle precisely – Figure 1 shows today's example. Many items are chamfered – even in electronics. For example, edge connectors on printed circuit boards often need to be chamfered to ensure that they do not damage the connectors they are being inserted into. Continue reading →

Posted in Metrology | 2 Comments

Calorie Per Acre Improvements in Staple Crops Over Time

Posted on 4-January-2017 by mathscinotes

My family has strong agricultural roots – mainly in dairy and potato farming – and our holiday conversations frequently turn to discussions of crop yields (bushels per acre or lbs per acre). As I listened to the discussion between my brothers on this year's crop yields, I realized that the yield numbers they were quoting were much higher today than we saw as children. This made me curious, and I decide to go out to the US Department of Agriculture's National Agricultural Statistics Service crop database and download CSV files on the yield of some key staple crops for processing by Power Query (i.e. recently renamed Get and Transform). I will be using this file to train my staff on defining Power Query functions. No macros were used in this analysis. Continue reading →

Posted in Excel, General Science, History of Science and Technology, History Through Spreadsheets | 5 Comments