A rare object called an Einstein Ring has been discovered by a team in the Stellar Populations group at the Instituto de Astrofísica de Canarias (IAC) in Spain. An Einstein Ring is a specific type of gravitational lensing. Einstein’s Theory of General Relativity predicted the phenomena of gravitational lensing. Gravitational lensing tells us that instead […]
At the turn of the 20th Century, Einstein’s theory of relativity stunned the physics world, but the experimental evidence needed to be found. And so, in 1919, another respected astronomer, Arthur Eddington, observed the deflection of stars by the gravity of the Sun during a solar eclipse. Here’s the story of that famous experiment.
We have no idea what it dark energy is, so how are we pretty sure it exists? I’ve talked about how astronomers know that dark matter exists. Even though they can’t see it, they detect it through the effect its gravity has on light. Dark matter accounts for 27% of the Universe, dark energy accounts […]