Author: John Carlson

The Four Galilean Moons of Jupiter

While watching the four Galilean moons of Jupiter buzzing around the planet recently, I was reminded of the historical role they have played in the advancement of science over the last 400 years. Starting with their discovery by Galileo in 1610, their existence helped prove that the sun was the center of the solar system not the earth.

Sundials in New York City

Sundials are an historic reminder of how man used to measure the time of day and are frequently used to inspire us about how time

The Doppler Effect and Cosmic Red Shift

  Christian Doppler (1803 – 1853) was an Austrian mathematician and physicist who is known for his principle, known as the Doppler Effect, that the

Binary and Double Stars

An interesting visual and telescopic challenge for viewing this spring is binary stars.  Most stars in our galaxy come in pairs or even triples.  Our