Astronomy dominates

Twice a year astronomy dominates the Macquarie University nighttime campus, when they hold their legendary astronomy open nights.

They've always been good, but I found last night that they've grown into quite sizeable and multi-faceted events.

The relevant car park had more telescopes than you could point a laser pointer at. They were trained on various star clusters, planets, and the moon. The many visiting stargazers never had to queue too long, so good was the array of viewing instruments on offer.

The (massive) laser pointer itself was trained on I'm not sure what, but anyway served as an excellent beacon to guide us in to the astronomical zone.

There were planetariums to visit, and information stands on astronomical societies and equipment. There were small scale space rockets seemingly for sale, the lot.

There were kids' activities involving robots and laser mazes. There were also talks about black holes, giant telescopes, and aboriginal astronomy.

We went to the main feature talk on cosmology ('A Long Time Ago in Galaxies Far, Far Away'), and it was excellent. It was delivered by Amanda Bauer, who's an astronomer and outreach officer at the Australian Astronomical Observatory at Coonabarabran. She did a fine job, so enthusiastically explaining her work on galaxy formation and evolution. She can't wait for Betelgeuse to explode and light up the daytime sky, or for the Andromeda Galaxy to finally get here, smash its way through our galaxy, and shake it all up for us a bit. She talked a lot about the red shift and how it was a marker for galactic speeds and distances. I noticed she was a bit into purple shift herself, with a purple astrogirl hairstyle.

I wanted to tell her afterwards about how I'm a bit of a red shift sceptic, but thought better of it. This doesn't go down well in gatherings of astronomers - I've tried before! Red shift is accepted as being due to motion away from us, and the more distant are objects from us, the bigger the red shifts, and therefore the bigger the speeds. As we're seeing the distant objects as they were billions of years ago, the relationship between red shift and apparent distance can be used to decide whether the expansion of the universe is increasing or decreasing or whatever. Nobel prizes were awarded a few years back when it was pronounced that the universe was expanding at an accelerating rate. It all depended on those studies, and the assumption that that red shift relationship held up at the very great distances, speeds, and times involved. To explain this accelerating expansion, a thing called 'dark energy' had to be invented, and astronomers have no idea what this dark energy is, nor indeed what dark matter is.  Between them they now need to make up most of the stuff of the universe. It's all getting uncomfortably complicated.

I think the next big Macquarie astronomy open night  is in October.