In the early Universe, things were quite different. The first stars were much more massive than stars today, and contained mostly Hydrogen. Astronomers have good ideas about how they formed, but other objects from around this time, namely black holes, are much tougher to account for. Early black holes were huge, with no explanation for how they grew so large. “Early” means “first Billion years after the Big Bang,” but even in that time, it’s hard to determine how observed black holes could grow as large as 100,000 solar masses. I say 100,000 solar masses, because that is the mass of two ‘seed’ black holes, discovered...
In 2014, comet C/2013 A1, known as sliding spring, came within 140,000 Km of the planet Mars. This is a bit more than a third of the distance from the Earth to the Moon. Comets are small, so gravitationally this interaction was insignificant, but from an electromagnetic point of view, things were shaken up big time! Comets are small, relatively speaking. A typical comet is a few kilometers across, about the size of a big city. But with sunlight melting ices and liberating gases and dust from the comet’s interior, the part of the comet we see in the sky,...
You may have heard about the leaked rumour about the discovery of gravitational waves from earlier this week. It was from Lawrence Krauss, who is an amazing science communicator and author, as well as a darn good astrophysicist. My earlier rumor about LIGO has been confirmed by independent sources. Stay tuned! Gravitational waves may have been discovered!! Exciting. — Lawrence M. Krauss (@LKrauss1) January 11, 2016 It’s safe to say that as a guy with an inside scoop on a lot of the latest science news, this is something to get excited about. The ‘LIGO’ he is referring to stands...