Doctor Who and the Ambassadors of Geek

Astronomers believe that at the heart of probably every active galaxy (i.e., one in which star formation is occurring) lies a supermassive black hole. And now, New Scientist reported last week,

[a]stronomers have obtained the closest glimpse yet of the supermassive black hole thought to lurk at the centre of our galaxy, the Milky Way. ...

Zhi-Qiang Shen of the Shanghai Astronomical Observatory in China and colleagues in the US examined the radio source at the centre of our galaxy, known as Sagittarius A. They used a network of 10 radio telescopes spanning 5000 miles, known as the Very Large Baseline Array (VLBA). The radio source is thought to mark the location of a titanic black hole that is guzzling surrounding light and matter.

The radio emissions are thought to come from highly energised gas closely orbiting the black hole, rather than the black hole itself. The team studied an area 12 times bigger than the central black hole. ...

If astronomers are able to see up to the edge of the black hole's event horizon - beyond which no light can escape - they may be able to determine whether Einstein's theory of general relativity holds up under high gravity conditions.

If it does, astronomers expect to see a dark shadow due to the black hole completely absorbing emissions from behind the black hole. Then a brighter ring should be seen around the shadow due to light rays that are flung around the black hole. However, this is a discovery that may yet be five to 10 years away.

"It could be we see nothing of the sort and we find something completely different," says Christopher Reynolds, an astrophysicist at the University of Maryland, College Park, US. "We might have to confront the notion that Einstein's theory was inappropriate."

And despite what the pseudo-scientific know-nothings would have you believe, the prospect of coming across something unexpected - coming up against something new - delights true scientists.