Monthly Archives: August 2013

Counting Nearby Stars

Posted on 31-August-2013 by mathscinotes

In my previous post, I casually stated that there are 61 stars in the region within 5 parsecs of the Sun -- at least according to the Gliese Catalog of Nearby Stars. I did not state where you could get … Continue reading →

Posted in Astronomy | Comments Off on Counting Nearby Stars

Radio Communication Between the Stars

Posted on 29-August-2013 by mathscinotes

Introduction A phone call from a cancer epidemiologist a few months ago got me thinking radio communication over long distance. This researcher was a sharp guy who immediately saw the dynamic range issues associated with cell tower communication -- the … Continue reading →

Posted in Astronomy, General Mathematics | 7 Comments

Battleship Rangefinders and Geometry

Posted on 23-August-2013 by mathscinotes

Quote of the Day Russia is a riddle wrapped in a mystery inside an enigma. — Winston Churchill. Introduction While reading a web page on WW2 naval warfare, I found some interesting material on how naval gunfire was spotted -- … Continue reading →

Posted in Naval History, optics | 19 Comments

Distance to the Horizon Assuming Refraction

Posted on 19-August-2013 by mathscinotes

While doing some reading on lighthouses, I needed a formula to compute the distance to the horizon as a function of height. This formula would give me an idea of how far away a lighthouse could be seen. Continue reading →

Posted in General Science, Navigation, optics | 26 Comments