Monthly Archives: May 2015

Pejsa's Projectile Drop Versus Distance Formula (Part 1 of 3)

I recently have had a number of readers ask me to continue my review of Pejsa's "Modern Practical Ballistics". The last major topic I have left to cover is his formula for the drop of a horizontally‑fired projectile as a function of distance. My plan is to derive the formula and present an example of its use. The derivation is not difficult, but it is a bit long and I will divide my presentation into a couple of posts. Continue reading

Posted in Ballistics | 11 Comments

I Must Be Old, All the Bugs Sound Familiar ...

I was reading an article this morning about a bug discovered in Boeing's 787 software that will occur after 248 days of continuous operation. The moment I read "248 days", I let out a sigh – I have seen that number before. Continue reading

Posted in software | 2 Comments