# Category Archives: General Science

## Modeling Coal Energy Output

I had never seen coal until my first trip to China when I saw people on bicycles transporting coal to their homes for heat. I started to wonder just how much coal a home would need for heating. I have seen numerous values for the heat content of the various types of coal. I recalled from primary school that there were three types of coal: anthracite, bituminous, and lignite. So I would have expected three values for the heat output of coal. When I actually looked, I found dozens of grades of three primary types of coal. Each of the different grades would generate different amounts of heat per kilogram. I thought I would take a closer look at how the heat output from coal could be modeled using regression and a simplified model based on chemical heats of formation. Continue reading

Posted in General Science, Statistics | 1 Comment

## 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

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## 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

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## 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

## Why Use an Antilog Taper Pot?

I have received a number questions lately on the use of log and antilog taper potentiometers. Because of these questions, I thought it might be useful to review why these tapers are used. Continue reading

Posted in Electronics, General Science | 1 Comment

## Drying Up the Mediterranean

One of my favorite audio books is titled The Earth: A Very Short Introduction (link). This book provides an excellent overview of basic geophysics. It is not a book about rocks, but rather a book about the structure of the Earth. This book contains an excellent discussion of the Mediterranean's periodic drying episodes that are collectively known as the Messinian Event, which occurred five million years ago during the Miocene era. Continue reading

Posted in General Science, Geology | 1 Comment

## Electricity Generation Percentage from Coal By State

I drive a short distance (7 km) to work everyday. On my drive, I often have to wait at a railroad crossing for a coal-train train to pass (typical example in Figure 1). I have never thought much how much my state depends on coal until I saw an interview with a Missouri senator who was talking about her state's dependence on coal for electrical power generation. I am currently teaching myself how to use the Power Query add-in for Excel, and I thought that generating a graphic of coal dependence by state would be a good Power Query/Visio exercise. Continue reading

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## How Many Red Blood Cells Do We Lose A Day?

I regularly visit the RefDesk website to pick up general information. Refdesk has a section that contains a Fact of the Day from the Random History website. Unfortunately, these "facts" are occasionally just plain wrong (example). Today, another one of these random facts did not seem correct and I thought I would perform a quick Fermi analysis here to show that it cannot be correct. I assume that they confused hours and minutes in their analysis. I will present my argument below. Continue reading

Posted in General Science, Health | 5 Comments

## Greenland Ice Sheet Trivia

I was reading an article today that says that geophysicists have figured out why the Greenland has been experiencing a flurry of magnitude 5 earthquakes. The scientists claim that the earthquakes are being caused by massive icebergs calving off the Greenland ice sheet in a manner that momentarily jams the movement of the ice sheet. The ice sheet and the calved iceberg are so massive that their interaction cause an earthquake.

While the earthquake information was interesting, there was a side discussion on the amount of ice required to raise sea level by 1 mm and seal level impact potential of a melting Greenland ice sheet. Continue reading

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## Owl Camouflage

I saw these two pictures today and I was stunned by the effectiveness of an owl's camouflage. I occasionally see owls – there is a great horned owl that lives near my house and it is amazing watching it fly at dusk. It has a very large wingspan. Continue reading

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