Not the whole galaxy of course, but something very energetic happened a little over three million years ago1 at the centre of our galaxy. The event, known as a Seyfert flare, lasted tens of thousands of years2 and spewed forth vast coned of electromagnetic radiation and plasma that had detectable effects 200,000 light years away, leaving it's signature on the the Magellanic Stream, a long trail of gas extending from the Magellanic Cloud galaxies.
Now the most probably cause for this explosion was something associated with Sagittarius A*, the titanic3 black hole at the centre of this galaxy.
This is interesting for a number of reasons, cosmological and gaming. Previously it was thought that the Milky Way (aka 'Mutters Spiral') wasn't a Seyfert galaxy, i.e didn't flare like this. And the bi-conical radiation flare probably eliminated any life in it's path, for many thousands of light years,
Now, to me a detonating black hole sounds suspiciously like what might happen if someone was manipulating such objects on a massive scale and made a mistake. Was someone attempting to emulate the development of time travel on Gallifrey? Who? What happened?
Comments? Ideas? Suggestions?
1. The Piacenzian age of the Pliocene epoch. Back when humanity, or what would become humanity, was starting to emerge. 2. Barely a heartbeat in cosmological circles. 3. About 4.25 million Solar masses. It's about 26,000 light year away.
Time, time,time, see what’s become of me. While I looked around for my possibilities... My AITAS files.
1) Wibbbly, Wobbly, Timey Wimey. Its likely even the greatest timelords don't always succeed on the first try. What if this was Omega's first attempt at making a power source for Gallifrey testing a few theories on a black hole in a minor galaxy and it went wrong or right.
2) It's dark in here. Similar to above but this is Omega's first attempt to break out, an attempt to break out that someone stopped.
3) Exterminate, Exterminate. A Dalek, Cyberman or other uknown enemy was running rampant desstoying all in its path and this gigantic flare was the only way to stop them.
4) The stars are right. Strand the party through some means and have them heading either towards this flare's time or another one in the future and to survive they need to figure out some way to prevent a black hole flaring. Worse combine this and 3 so it seems like they need to not only die but destroy an entire section of the galaxy to save the universe.
Its an interesting concept suggesting all sorts of possible story ideas.