Author Archives: mathscinotes

Example of a Useful Histogram

Sometimes all it takes is to use a histogram maker to create a graph, for example, to help provide you the clue you need to solve a mystery. Currently, I am working on reducing the failure rate of Avalanche Photo-Diodes … Continue reading

Posted in Electronics | Comments Off on Example of a Useful Histogram

Candle Flame in Space

Quote of the Day Only enemies speak the truth. Friends and lovers lie endlessly, caught in the web of duty. — Stephen King I saw this photo posted by Robert Frost here. It shows a flame on Earth (left) and … Continue reading

Posted in Astronomy, General Science | Tagged | Comments Off on Candle Flame in Space

World War 2 Industrial Casualties

I like to watch authors discuss their history books on BookTV. I listen to BookTV while I work around the house. One weekend, I heard two historians (I did not write down their names) discussing World War 2 and each mentioned a statistic that sounded something like this (my wording). Continue reading

Posted in History of Science and Technology, History Through Spreadsheets, Military History | 24 Comments

Another Interpretation of the Ballistic Coefficient

Introduction I love to look for physical interpretations of various constants. Sometimes it is impossible to come up with an interpretation, but such is not the case for the ballistic coefficient. This morning I read a very solid piece of … Continue reading

Posted in Ballistics | 9 Comments

16-in Battleship Gun Ballistic Coefficient

A projectile with a large ballistic coefficient is less affected by drag than a projectile with a smaller ballistic coefficient. We can use the the ballistic coefficient to compare the effect of drag on different projectiles. A 16-inch projectile goes so much farther than a rifle bullet because the drag on the 16-inch projectile is relatively small compared to its momentum. Ultimately, this is because mass increases by the cube of the projectile dimensions and drag increases by the square of the projectile dimensions. This means that larger projectiles tend to have higher ballistic coefficients and drag has less effect. Continue reading

Posted in Ballistics | 5 Comments

Parameter Determination for Pejsa Velocity Model

I have had several people ask me questions about the Pejsa ballistic model (previous post) and I thought it would be useful to include some additional posts on the topic. In this post, I will discuss how the formula and parameters were determined for the velocity versus range formula for the range of velocities from 1400 feet per second to 4000 feet per second (sorry about the use of US customary units). Continue reading

Posted in Ballistics | 4 Comments

Image of a Submarine At Periscope Depth

If you have ever wondered what a submarine looks like at periscope depth, here is a photo of the USS Key West (SSN-722). Source is the Wikipedia.

Posted in Naval History, Personal | Comments Off on Image of a Submarine At Periscope Depth

My Favorite Animation Video

I love animation and I just stumbled upon an excerpt from a television show that I saw as a boy -- "An Adventure in Art." I found this video fascinating. As an added treat, one of the artists featured is … Continue reading

Posted in Personal | Comments Off on My Favorite Animation Video

Physical Interpretation of a Model Parameter

Introduction I frequently get very specific questions on my posts. Normally, I simply reply directly to the question. One recent question required an answer that I thought might be interesting to a broader audience. Background Here is the question that … Continue reading

Posted in Ballistics, General Mathematics | 7 Comments

Measuring the Distance to the Moon and Photon Counting

Introduction While looking up some information on the Moon, I ran into an interesting set of web pages that describes an experiment to measure the distance to the Moon with centimeter-level accuracy. This experiment sends a stream of laser pulses … Continue reading

Posted in Astronomy | Comments Off on Measuring the Distance to the Moon and Photon Counting