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...
If you actually had the ability to see X-Rays, the world around you would look pretty boring. Actually it would be invisible, since nothing around you gives off X-rays. You might be able to see an imaging device if you live or work near a medical office, but that’s about it. If you looked at the night sky, you would see many interesting sources of X-Ray light, mostly from active black holes in our own galaxy and beyond. Recently a high-resolution scan of the Andromeda Galaxy revealed a plethora of sources, showing where black holes and neutron stars are feeding...
Honestly this could be the name of a new TV show, similar to ‘when buildings collapse,’ or ‘here’s what Kim Kardashian did today.’ I’ll take the colliding galaxies, simply because they can hold my attention longer. Galaxy collisions are some of the most massive and long term events in the universe. The result is the formation of billions of stars, the change in orbit of Billions more, and the complete restructuring of a galaxy. Since we see a snapshot of the Universe whenever we look at a single galaxy, we tend to see collisions happening at all stages of the...
One of the big questions in astrophysics is about variation of the laws of Physics. The laws we know and are familiar with; angular momentum, gravity, energy, are the same everywhere on Earth. But what about beyond Earth? The universe is so large and so vast, we may be in a local region where the laws of Physics are set, and our laws may be different from a distinct region somewhere else in the universe. The good news is that we can make predictions based on our understanding of physics. And with our powerful telescopes that allow us to view a variety of...
There are multiple types of Supernovae that have been observed throughout the Universe. Classifying them is difficult because the conditions of each one are not always similar. There are now seven different classifications of these stellar explosions, that are divided (and subdivided) by their spectral characteristics. By studying the light from supernovae, we can determine what type it is, and identify what kind of stellar environment led to its destruction. The supernova remnant 3C 397, shown above in the constellation Aquilla at a distance of 33,000 light years, has thought to have been expanding for 1-2 millennia. Originally thought to have...
