FW’S NOTEBOOK #2 – Fagnano Problem

Lurking in my recent research readings, this is a problem at the intersection of middle school geometry and quantum chaos ...  This week's post was delayed such that certain subscribers taking final exams won't be disturbed. Hope you all had fun. Question: Inscribe a triangle of minimum perimeter inside an arbitrary acute triangle. Demonstration I. … Continue reading FW’S NOTEBOOK #2 – Fagnano Problem

FW’s NoteBook #1 – The Spring Pendulum Problem

Will I have some theme for these posts? The question is, again, rather easy to state.  But to me, it is one of the best introductory examples to ODE solving and chaos with a simple physical model. Q1. Describe the motion of a simple pendulum were you to replace the massless string with a spring … Continue reading FW’s NoteBook #1 – The Spring Pendulum Problem

What Does it (really) Take for an ECLIPSE?

I guess you know the drill by now. Round earth with a moon whizzing around, and the pair occasionally block sunlight from each other.  Neat stuff. Do you want to see an actual ray diagram of that? Yes! Well, I drew one in Adobe Illustrator, and then converted it to html. Edit: WP Does not … Continue reading What Does it (really) Take for an ECLIPSE?

FW’s Notebook #0 – Opening and Big CIRCLE GEODESICS

Putting the iPad to the same good use, but publicly. Summer is beginning, and my first three years of formal college education has come to an end. During this period, I have perfected the skills of Googling for good questions and solutions on a variety of subjects, *rarely* for homework, and for self-study. It's time … Continue reading FW’s Notebook #0 – Opening and Big CIRCLE GEODESICS

What is the Most Frightening Celestial Object?

A few days back on Zhihu.com at home, there was an astronomy question that made it onto the "Trending Q&A" list (quite impressive for my homeland), "What is the most frightening celestial object known to science?" Not surprisingly, in the scientifically literate answers -- many of which I might be interested in covering in the … Continue reading What is the Most Frightening Celestial Object?