Monthly Archives: September 2015

My Sister in Math Class

My sister posted this video on her Facebook page while stating it described her in math class. There is some truth to this statement. It could also have been used to describe any of her four brothers in nearly every classroom. Continue reading

Posted in Humor | 5 Comments

Mass-Energy Conversion Example

Since 2015 is the 70th anniversary of the end of World War 2 (WW2), C-SPAN has been running a number of oral history interviews with people who worked on the Manhattan Project. I have found these interviews very interesting. You can find them on YouTube and watch them for yourself. Continue reading

Posted in General Science, History of Science and Technology, Military History | Comments Off on Mass-Energy Conversion Example

Coal Train Daydreams

Because of where I work and live, I regularly wait at train-road crossings while coal trains pass in front of me. I get bored while sitting there and I start to think about the amount of coal that is being consumed by one of our local coal-fired power plant known as Sherburne County Generating Station or Sherco for short. I will present my estimates here and show that they agree with the numbers our local power producer is stating for this plant. Continue reading

Posted in General Science | Comments Off on Coal Train Daydreams

Circular Saw Depth-Of-Cut Formula

I recently bought a battery powered, 6.5-inch diameter, circular saw from Milwaukee. I REALLY like this saw. I have been using it at my cabin in Northern Minnesota, a place where dragging around electrical cords is painful. This saw has quickly become one of my workhouse tools. Continue reading

Posted in Construction, Geometry | 16 Comments

Tree Height Measuring Example

I have been testing a number of Android applications that are intended to measure the size of objects knowing their range or vice versa. One application that I have found particularly useful is called Baumhöhenmesser – Tree Height Meter (my translation) – which is an application written by a German developer. I have found this application particularly useful, and I thought I would review its operation here. It is part of a suite of Android applications intended for forestry management. This app makes excellent use of the Android's ability to measure angles. Continue reading

Posted in General Mathematics, Geometry | 3 Comments

Glacier Melting Math

My wife and I are currently on an Alaskan cruise with friends that used to be our neighbors when our children were young. Our cruise ship is the Millennium, which is part of the Celebrity fleet. We are currently moored in Juneau, where we visited the Mendenhall glacier. While at the glacier, I talked with a local Forest Service guide about the rate of glacier melting. I also made a few measurements using my phone and a bit of math then ensued, which I will discuss here. Continue reading

Posted in Geology, Personal | 2 Comments