The efficiency of LED light has been a boon for humanity, and a bane for astronomers.
How Green Was My Meteor
Lots of objects in the night sky are green, but they are green for a variety of different reasons.
Violet Sky
You might know why the sky is blue, but why isn’t the sky violet?
A Light Change
Was the speed of light much faster in the early universe?
A Dance Of Light
The interaction of light and glass is extraordinarily complex, as you can see in the video above.
The Optical Trifecta
To prove Einstein’s theory of special relativity, three different experiments had to be performed.
Cosmic Expansion and Tired Light
If light from a distant galaxy is redshifted, and the energy of a photon depends upon its wavelength, doesn’t that mean the photon is spontaneously losing energy? What about conservation of energy?
Relativity Wins Again
One of the great things about science is how we keep testing our assumptions. Even when a phenomenon has been rigorously tested, we still push the limits of observation. Take, for example, some recent research on the speed of light.
How to Travel Faster Than Light Without Really Trying
It turns out there are several ways things can travel faster than light, depending on what you mean by a “thing,” “faster-than-light,” and “travel”.