I saw an article last night about gravitational waves, that a black hole merger was detected by not just the Laser Interferometer Gravitational Wave Observatory (LIGO), but by another project altogether, the Virgo collaboration. This is the first gravitational wave detection confirmed by two separate groups, and it marks the beginning of a new era of experimental science, the first in astronomy in over two decades. Around 1.8 Billion years ago, to black holes merged in a faroff galaxy. They had masses of 31 and 25 times that of the Sun, though with their incredible density they would each be...
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....
The merger of black holes proven by LIGO yesterday looks amazing in this simulated view in today’s APOD. What would normally take a third of a second has been stretched out to show the entanglement. And remember, these things are far more massive than the Sun, so to be moving this quickly and merging is an extremely high-energy interaction. And kablammo, matter converted to energy, gravitational waves aplenty, and an even bigger black hole. Happy Long Weekend!
On the York Universe radio show this past Monday evening on astronomy.fm, I was having a discussion with another host about how so many things in Astronomy can take Millions or even Billions of years, yet there are still all kinds of phenomena that happen in seconds, hours, weeks, years, or on the scale of human lifetimes. Stars live for hundreds of Millions of years at the low end, yet the intense brightening from the Supernova death of a massive star lasts for only a few days or weeks. It’s as if the Universe is piquing our interest with short...
The deeper we peer through the cosmos, the more we are looking into the distant past. Light from other galaxies takes millions of years to reach us, and so when that light has finally arrived at Earth, it is millions of years old, a snapshot in time of the distant galaxy. The furthest we can see is so far back in the history of the universe, that galaxies haven’t even formed yet. As we look at the large-scale structure of the Universe, we see it filled with a cosmic web of galaxy clusters, containing tens of thousands of galaxies each....
