Dark matter could be almost anything. With little data other than how much total dark matter mass exists, we can’t decode much about what individual chunks of dark matter might be made of. I’ve talked before about Massive Compact Halo Objects (MACHOs) and Weakly Interacting Massive Particles (WIMPs), but these are just two possibilities. Other theorists have talked about Modified Newtonian Gravity (MNG), where gravity may work differently on the grand scale than it does on our small Earth scales. Or perhaps it’s something I haven’t seen before. Maybe what we call dark matter is just a large population of ancient black holes....
Today, the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) is expected to announce a monumental discovery that is 100 years in the making. Theorized by Einstein’s general relativity in 1915, gravitational waves are ripples in space-time, similar to sound waves, but much tinier. The search has been ongoing for decades, with no results. Until now. LIGO has the most sensitive gravitational wave detector ever conceived – in two interferometer facilities in Livingston, Louisiana and Hanford, Washington. They use a laser split along two axes to give an in-phase beam. If gravitational waves along one of the axes affect the beam, it...
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...
If you ask someone what the craziest, most powerful, energetic, and enigmatic thing in the universe is, chances are they will say a black hole. After all, we know so little about them, we have never directly seen one, and we can see their influence across space and time. But there is apparently another notch on the crazy powerful cosmic object front. Like turning the volume knob to eleven, a binary system of supermassive black holes has been discovered in a nearby quasar. A quasar is an incredibly bright core of a distant galaxy, shining brighter than the entire galaxy...
Have you ever heard of an object called ‘Hanny’s Voorwerp?’ It’s a thin wispy ghost-like blob at the edge of a Galaxy. It was discovered by Dutch schoolteacher Hanny van Arkel in 2007 as she was classifying galaxies as part of the Galaxy Zoo project. Since then, astronomers have been studying its origin, as it was the first of a brand new phenomenon in astronomy. This past week, a new data set of wispy trails at the edge of Galaxies have been released as part of a Hubble study by Bill Keel of the University of Alabama, Tuscaloosa. The new Hubble...
The biggest problem in theoretical physics today is the marriage between Quantum Mechanics and Gravity. Throw in the fact that whatever theory comes out of it has to additionally be able to explain Dark Matter and Dark Energy, and we have ourselves a massive problem to solve. How do we reconcile the seemingly random probabilistic nature of quantum mechanics with the smooth, pliable space-time of General Relativity. We have two incredible theories that explain the Universe, make predictions accurately, and have led to amazing advances in technology and understanding, yet they completely disagree with each other at common scales. So...
A vast number of Galaxies in the Universe have a central black hole that is incredibly massive. The Black Hole at the centre of the Milky Way, dubbed Sag A*, is estimated to have a mass as high as three Million Suns. We generally can’t see black holes, but when they start to pull in matter from surrounding gas and dust clouds, the material forms a disk around the star. This accretion disk can heat up to incredible temperatures and emit X-rays and other high energy light, allowing us to see where the black holes are. Sometimes the light from...
Quasars are Galaxies with incredibly massive Black Holes at their centre. These Black Holes are fuelled by a swirling disc of material that can be ejected in a long jet along their axis of rotation, all due to the conservation of angular momentum. This accretion disc can be so hot that it causes the central region of the Galaxy to shine more brightly than the entire Galaxy of stars surrounding it. A Belgian team using the Very Large Telescope (VLT) studied a population of 93 Quasars spread over Billions of Light-Years, and noticed that the rotation axes of the Quasars...
I’ve talked about black holes previously, and only in our own Galaxy, and only the big one in the middle, Sag A*. When I speak with the public and with kids about Black Holes, most people never really understand that there aren’t just one or two kicking around, but potentially there are as many as a Billion Black Holes in our own Galaxy! The problem is, we are not very good at finding them. It makes sense, they give off no light, and we can only find them through indirectly measuring their effects on the surrounding environment. We can sometimes see...
