A Ring of Fire

A direct consequence of Einstein’s theory of general relativity, and an observational way to prove it, is gravitational lensing.  It requires a powerful gravitational source to work, such as a galaxy or cluster of galaxies.  It works in a similar way to a lens of glass, where rays of light are bent toward a single source, increasing the brightness.  In this case, instead of glass, the bending of the rays is due to the curvature of space. Light rays coming from the source would otherwise miss Earth, but instead are bent toward us when there is a massive object in front of it.  It’s...

“Without Gravity”

It always fascinates me to see videos and photographs from the International Space Station (ISS), how simple day to day activities are so altered because of the altered Physics of constant free fall in orbit around the Earth.  Many of the videos are showing what people call the ‘effects of zero gravity.’ This is actually not the case.  There is gravity in space.  Let’s take a closer look at the situation of an ISS astronaut. If we do the math (I do realize the term ‘do the math’ turns away a lot of people, so I will keep it short),...