As a child, I didn’t associate the night sky with science – it was just one of those amazing, magical parts of nature. But looking at the planet Mars for the first time as a 12-year-old with my Dad catalysed everything for me. I just fell in love with astronomy.
I realised astronomy wasn’t just for old guys in wigs like Isaac Newton – it was a modern, tangible opportunity for me to actually go to university and become a scientist.
I’ve since helped to build some of the world’s most powerful telescopes – but I’ve never actually owned one. We just saw an article in the newspaper that said you could see Mars with the naked eye, so we found a star map in an op shop – the 1957 Norton’s Star Atlas. It was this beautiful, old hardbound thing with pages and pages of different views of the night sky in different constellations. I totally nerded out on it.
I can reliably call it an obsession. I joined my local Astronomical Society, and some of the members had telescopes that I could look through on special observing nights. And that made me associate it with science. I realised astronomy wasn’t just for old guys in wigs like Isaac Newton – it was a modern, tangible opportunity for me to actually go to university and become a scientist. I ended up doing my PhD in radio astronomy at Jodrell Bank Observatory, University of Manchester, UK.
The incredible Lovell Telescope located there is 76 metres across. It’s basically a gigantic bucket to scoop up radio waves from space. Radio waves are exactly like light, just a kind of souped-up, supersized version that’s stretched out over a longer wavelength.
With radio telescopes, we can see things that happened billions of years ago. It’s a time machine.
For my PhD I studied how stars form. They’re actually born inside dense, dusty, dark clouds in interstellar space. And we can’t see inside those clouds with normal light. But with radio waves, we can see very deep into these clouds, and we can actually measure the chemistry inside there, and ascertain the physical and magnetic conditions under which these stars are forming.
Radio waves help us to see the beginning of the universe. Light from the Big Bang is stretched out by the expansion of the universe into a radio frequency spectrum. With radio telescopes, we can see things that happened billions of years ago. It’s a time machine.
In 2012 I began work as the CSIRO’s Project Scientist for the Square Kilometre Array Telescope. The SKA is going to have 130,000 individual antennas in Western Australia, and many hundreds of dishes in South Africa. It will have huge collecting areas to see very, very faint things in the distant universe, things we haven’t seen before. And the massive spread of the telescopes will give us a very high resolution to see the details.
We’ll be able to create images, so people can understand what we’re detecting, but radio images are a bit ugly. All we really measure with these telescopes is a voltage in a piece of wire. So we have to use false colour to cleverly turn it into an image in a hugely complex process that takes a supercomputer and lots of mathematics. We don’t get the pretty pictures that telescopes like Hubble and JWST produce, but we are blessed by the information that we gather.
Read more: SKA’s low-frequency radio telescope promises a first look at the origin of the Universe.
Construction should begin very soon, probably next year. And within the next few years there will be infrastructure and testing going on. Then we can start looking at the beginning of time – less than half a billion years after the Big Bang, 13.2 billion years ago. We should be able to see the first stars and galaxies forming, and get a picture of how that process happened. It will really start to tell us a story of the early universe, the creation of what we see today, and the creation of us. We want to witness the time when the universe became light-filled with stars and galaxies – the end of the cosmic Dark Ages.
I was also the project scientist for the Australian SKA Pathfinder telescope for about seven years. It’s the most capable and fastest survey telescope of its type in the world. I’ve actually weighed a supermassive black hole using it – it came to around 3.8 billion solar masses, a very heavy black hole caused by at least two galaxies colliding.
That telescope has helped us to discover some incredible things like Fast Radio Bursts throughout the universe – these very mysterious explosions that will hopefully soon teach us more about collisions between dense stars or black holes, or whatever they end up being. We don’t know yet.
The next big thing really in astronomy is actually being able to make sense out of this huge volume of data.
The sheer amount of data created by these new telescopes is absolutely eye-watering. The Australian SKA Pathfinder, on its own, produces raw data at a rate of 72 trillion bits per second. The SKA will be way more: it will exceed the global Internet traffic by many times – just a huge torrent. The next big thing really in astronomy is actually being able to make sense out of this huge volume of data.
We can get all the information we want from the universe, but the hard part is extracting meaning from it. The computer skills of astronomers have gone up massively recently – there are a lot of projects now where people are doing PhDs on machine learning and artificial intelligence, developing algorithms to automatically detect interesting objects. That’s the really cool cutting edge happening right now.
As told to Graem Sims for Cosmos Weekly.