No aliens – astroengine.com

alien_world1 — An alien civilization could be transmitting, but we can't hear them (© Steve Swayne via Flickr)

As I was watching Battlestar Galactica last night, I was thinking about the lack of alien civilizations in the show. To be honest, I tire easily of humanoid alien beings with curiously shaped heads synonymous with Star Trek et al., so I’m loving the fact a far-off human colony created their own evil race, the Cylons. So far, so good, I’m getting sucked into BSG (will it be as good as, or even better than Bablyon 5? That has yet to be seen, but it looks promising).

These thoughts took me back to an Astroengine article I wrote in November with my usual gripe about our obsession for looking under rocks on Mars (The Search For Life, What’s the Point?). I reached the conclusion that I’d much rather be pottering around in an empty cosmos, devoid of life, than bumping into an angry neighbour who wants to probe/assimilate/hybridize me. Science fiction musings I know, but it isn’t that far from some of the conclusions that could arrive from using the famous Drake equation that underpins our incessant search for intelligent extraterrestrial life.

Today, I was referred to some research addressing the Fermi Paradox, although we haven’t heard from our extra-terrestrial neighbours yet, doesn’t mean they’re not transmitting. The galaxy could be teeming with intelligent aliens, but we just can’t hear them…
Continue reading “If There’s an Alien Race Living on our Doorstep, Why Can’t We Hear Them?”

Yearly location of stars within 0.2 parsecs from Sagittarius A* orbiting the common, compact radio source (A. Ghez)

We are told there is a supermassive black hole living in the centre of our galaxy. Apparently, supermassive black holes can be found in the centre of most galactic nuclei, and all the stars within the surrounding galactic disk will orbit around it. But how do we know there is a huge black hole in the centre of the Milky Way? What evidence is there? It turns out there is quite a lot, actually.

In a recent review of the subject, the radio emissions observed since the 1950’s are examined. However, probably the most striking piece of evidence is the figure to the left. Of course, we know black holes exert a massive gravitational pull on local space, and by observing the centre of our galaxy, we find there is a huge gravitational influence over a compact cluster of stars, all orbiting a common point, reaching orbital velocities of 5000 km/s…
Continue reading “Meet Sagittarius A*, Our Very Own Supermassive Black Hole”