A new survey of distant quasars shows that dark matter isn’t warm and fuzzy.
How Computer Models Helped Discover Gravitational Waves
To help distinguish a real signal from the noise you need to know what a real signal might look like. That means you need to use general relativity to create models of things such as binary black holes.
Edge Effect
While there is lots of evidence showing black holes exist, we’d really like to observe them more directly.
Cosmic Cryptology
It’s an interesting idea to use the secrets of the universe to keep your own secrets.
Spin Flip
As two black holes are close to merging, their spins do a gravitational dance that cause them to change direction.
More Power
This month I’ve upgraded my home computer. My new desktop has faster processor, double the storage space, and quadruple the RAM as my venerable old laptop. I don’t upgrade very often, so when it happens there’s a very noticeable uptick in computing power. It’s something we’ve become rather accustomed to. With each new phone, computer or tablet we have more power at our fingertips. This consequence of Moore’s law has also revolutionized the way we do astronomy.
Clockwork Twin
The Antikythera mechanism is a strange astronomical calculator. It was discovered in a shipwreck off the Greek island of Antikythera in 1900, and is astoundingly complex. It was a bronze clockwork device with at least 30 gears, and looks like something from the 1400s. But recent research indicates that it likely dates earlier than 200 B.C.
Carbon Chain
One of the common ways we can map the distribution of matter in a galaxy is by observing the light emitted neutral hydrogen. This works pretty well because hydrogen is the most abundant element in the universe, and its emission lines are pretty distinctive. But for distant galaxies hydrogen emissions aren’t very bright. To observe them you need really long exposure times, and that limits the amount of galaxies you can observe. One alternative is to look at the emissions of carbon instead.
Galactic Scale
How do you weigh a galaxy? With planets we can measure their distance from the Sun and their orbital speed. By observing their motion in detail we can calculate their mass very precisely. For binary stars we can use a similar method. Observe the size of their mutual orbits and their orbital period, and by Kepler’s laws you can determine their mass. We can’t do that with galaxies, so what do we do?