Category Archives: General Science

Daily Tree Consumption for Toilet Paper

I was reading an article on National Geographic when I spotted an interesting factoid about the impact of Toilet Paper (TP) world-wide tree consumption.

Toilet paper wipes out 27,000 trees a day.

Like many factoids, I doubt there is a way to actually measure this number – it can only be estimated. Thus, it is a prime candidate for a Fermi solution. Continue reading

Posted in General Mathematics, General Science | 4 Comments

Effect of Earth's Curvature on Suspension Bridge Dimensions

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 | Leave a comment

Larsen Ice Shelf and Potential Sea Level Rise

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

Calorie Per Acre Improvements in Staple Crops Over Time

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 | 1 Comment

Airliner vs Car Fuel Usage

As I looked at the cost of airline tickets versus driving, I became curious as to how much fuel was used to fly me out to a Montana airport such as in Bozeman or Butte. I was surprised to learn that airliners can be quite fuel efficient compared to cars. This post contains my analysis. Continue reading

Posted in General Science | 7 Comments

Dealing with Climate Change Denial

I have lunch with all sorts of people. Occasionally, I end up sitting with a climate change denier, which happened today. Usually, I do not say anything because I really do not want an argument.

Today, I decided to mention Figure 1, which summarizes a set of measurements made since 1900 that show that sea level is rising. I then asked the climate change denier if they can explain the fact that sea level is rising –a fact has been confirmed by multiple measurements taken at multiple sites over more than 100 years. Continue reading

Posted in General Science | 1 Comment

Volume Reduction in Ethanol-Water Mixtures

I recently toured a winery and, during the tour, I saw a number of charts related to various properties of ethanol and water mixtures. I was a bit puzzled when I saw Figure 1, which is a chart that I had never seen before. Figure 1 shows the amount of volume reduction experienced by an ethanol-water mixture compared to the separate volumes of the water and ethanol. I became curious about the chart and decided to see if I could derive these results on my own. Continue reading

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CO2 Tonnage Added To Atmosphere Per Year

My youngest son told me that I needed to watch the new Cosmos series with Neil deGrasse Tyson. I was immediately hooked – it is a masterpiece of scientific exposition for a general audience. I thought the original Cosmos with Carl Sagan was excellent, but the progress in computer graphics during the intervening decades makes the program visually stunning. Continue reading

Posted in General Science | 5 Comments

Converting Specific Humidity to Relative Humidity

I often have to interpret odd test requirements. In a test specification based on GR-487, a humidity test is called out where we need to have a fixed specific humidity (i.e. 24 grams of water vapor per per kilogram of air). For a given specific humidity, the relative humidity will vary with temperature. Since my test gear can control relative humidity, I need to derive a relationship between relative humidity and the specific humidity, which I show in Figure 1. Continue reading

Posted in General Science | 5 Comments

Nuclear Spent Fuel Annual Generation Rate

A coworker was telling me about a relative of his who is an engineer at a nuclear power plant. One of his relative's many jobs is to babysit nuclear waste casks (Figure 1) – a task which includes monitoring their temperature. These casks are warmed from the inside by the radioactive decay of the waste they hold. As I understand it, this job has good long-term security because these casks are going to be a safety hazard for tens of thousands of years. Continue reading

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