Radio Astronomers are LOOKING not Listening to the Cosmos
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One of the myths about the science of radio astronomy is that scientists are listening to the cosmos in hopes of finding alien life. This myth has become part of popular culture primarily because of the word, “radio” and because of the very popular movie, Contact where we see Jodi Foster intently listening with her headphones on. But the truth is, radio astronomers are actually LOOKING at data that they collect with those large dish like telescopes.
I found this information to be very interesting because I too thought radio astronomy was all about sound and noises like the ones you would hear in between radio stations.
Lucky for me, I know an awesome scientist who studied this type of radio astronomy and with her help, I did an art project so together we could explain what radio astronomy really is about.
Dr Gugliucci gave me some tips on how the radio astronomy data was displayed, such as what colors scientists apply to that data so I could make an art plate about the topic. She said that different scientists prefer different colors, some use black and white tones and others use color. She said her favorite is the blending of reds and yellows because it often makes the data look like fire in the sky as demonstrated by this image of Cygnus A.
I loved that image! I decided to use that color palette for my piece of art. Then, Dr Gugliucci was kind enough to give us this quick overview of the topic to help people like me, better understand what radio astronomy actually is about.
Here is what Dr Gugliucci had to say:
Radio astronomers look at the sky in a very unique way. Although we usually think of “listening to the radio,” radio waves themselves are light and not sound. Radio astronomers actually see the Universe with a form of light that is invisible to our eyes. To a radio telescope, the Universe looks very different from what we’re used to seeing with our eyes or optical telescopes. There are supermassive black holes powering humongous jets of tiny particles moving near the speed of light, and these jets give off radio light that our dishes can see. Gas clouds emit radio waves as well, giving off specific frequencies of light depending on what atoms or molecules are present. With radio telescopes, astronomers have mapped the arms of our Milky Way Galaxy, seen the birth of stars in regions otherwise clouded from our view by dust, mapped the remnants of massive stars that died in violent explosions called supernova, seen the action of black holes throughout the Universe, and mapped the faint echo of the Big Bang. One day, we may pick up the radio signals being given off by an extraterrestrial civilization and find out once and for all that we’re not alone in the Universe.
~Dr Nicole Gugliucci
And here are the images from the decorative ceramic plate that I made:
We don’t hear radio waves directly, even using a radio set. We hear sound waves, which the radio set produces from the radio waves. Most radio signals vibrate far faster than the sound waves we can hear, so the sound is in a sense impressed onto them. It’s a bit like the way a picture can be drawn onto canvas which is made of a fine-grained material; if the strands making up the canvas were an inch apart it wouldn’t be any use for painting on. Similarly a radio “carrier wave” has to vibrate more rapidly than the signal it carries, so even if we could hear radio directly, we couldn’t, if you see what I mean!.
It’s just a quirk of the language that we have taken to calling wireless sets radios, and hence created potential confusion between the waves that carry the signals and the apparatus that receives them. A TV set converts radio waves into both pictures and sound, but no one assumes we can both see and hear radio signals, because TVs aren’t called radios!
I’m a tour guide at an astronomical observatory. We don’t have radio telescopes, but we have a gamma ray telecope (the MAGIC). I usually explain gamma rays and infrared as invisible colours, and say that the universe looks as different in radio waves/infrared/gamma rays as the human body looks in X-rays.