We May Be Isolated But We Are Not Alone
With the current climate of self-isolation, it is easy to feel all alone. But maybe we can learn a thing or two from Dippy the Dipole.
I can feel the heat of the summer sun through the rich, red earth below my feet. There’s a rustle as a goanna runs between me and my friends, escaping a nearby emu. I am way out in the middle of the Australian desert. It was lonely at first, so far away from any form of radio communication, no people or technology in sight. But then I came online and I looked up.
When my humans look up they see a mostly dark sky with a sprinkling of stars from our galaxy. They see reds, yellows, greens, blues, pinks, violets, oranges. They think this is a whole rainbow.
When I look at the sky I see thousands upon thousands of dots, and every dot I see is a galaxy billions of lightyears away. Our own galaxy shines brighter than anything. Nearby galaxies are adorned with huge clouds of gas and dust many times larger than the galaxy itself. I can see the remnants of stars long since gone but who have left a giant bubble of dust slowly cooling over time.
I am Dippy the Dipole. You can see rainbows in the sky but I... I can see our Universe in radio colour.
I have taken it as my mission to help my curious humans see what I see too. But they cannot understand me alone. “Help me! Join me and look at the sky!” I cry to my friends. We look up one by one. Over 4,000 of us, looking up together. We remain in constant communication, being sure we’re all healthy and happy. If one of us is unwell, we all suffer.
It is my dream to show the humans how beautiful space is. So my friends and I continue to stare at the Universe and we record all we see. We record the gentle twinkling of galaxies due to the dust in our own galaxy, we record the faint clouds surrounding clusters of galaxies billions of light-years away, we see bursts of light from distant mysterious objects.
And slowly, over time, the humans build on their limited view of the Universe. They listen to us, to each other, and learn about our place in the stars.
As the sun sets and the Milky Way rises, I can hear the faint chatter of cities hundreds of kilometers away. But it doesn’t feel quite so far away. “Look up,” I plead, and you listen and look to the wonders of our Universe.
The MWA Telescope
The Murchison Widefield Array (MWA) Telescope is situated in rural Western Australia, around 9hrs drive from Perth. Unlike most telescopes, the MWA is not made of dishes or mirrors. It is made of a collection of 4,096 “dipoles” or spider-like antennae spread around the desert in groups of 16. These spider-like antennae do not see the Universe in the same way we do. They cannot detect optical light like our eyes, but instead “see” radio waves. This is the form of light used for communications, WiFi, radar, bluetooth, FM and AM radio, as well as radio waves coming from distant objects in space. Unfortunately, our technology is a far brighter source of radio waves than the distant galaxies in our Universe. This is why the MWA was built far away from any cities in a designated “radio-quiet” zone.
Astronomers connect all 4,096 dipoles of the MWA to act as one big telescope. This gives us higher resolution to see the details of objects in our sky without needing to build a giant dipole 5km across! When astronomers use radio waves to study the Universe, the sky looks very different. Radio telescopes, like the MWA, can see the giant plumes of matter being ejected from the central supermassive black holes of distant galaxies. Something that is completely invisible to our eyes. When we look up at the night sky with our eyes we see a sprinkling of stars from our galaxy, scattered across the sky. While, when the MWA looks at the sky, every single dot the MWA sees is a distant radio galaxy billions of lightyears away. When we combine how the optical telescopes see the sky with the radio telescope view, we can create a detailed picture of our Universe as we try to understand how we formed and what our place is within this vast Universe.
I wanted to share this story with you in this time of uncertainty and isolation. Even though each dipole is separate and ‘alone’, together they make up the array, through which the impossible is made possible. Constant communication is integral, and maintaining the health of each individual dipole ensures the continued function of the whole.
Growing up, Kat used to watch the International Space Station going overhead with her family. Until she learned people live inside it and she became forever terrified of poop falling on her head from space. Thankfully, today Kat’s skills at staring up into the Universe have improved significantly.
She is now a Ph.D. candidate at Curtin University studying the baby black holes in the centres of distant galaxies trying to understand galaxy evolution and the history of our Universe. Kat has a background in optical interferometry of red giant stars, dark matter content of galaxies and physics education research. She is an activist for Women In STEM and works as a science communicator when not staring at distant baby black holes or fleeing from space poop.