For most of us, the idea of astronomy is something they directly connect to “stargazing”, telescopes & seeing magnificent
displays in the heavens. & to be sure, that is the exciting area of
astronomy that accounts for it’s huge popularity. So to the uninitiated, the idea of “radio astronomy” seems weird. There's two reasons for that. First is that humans are far more visual than audio oriented. & the second is that radio astronomy doesn’t involve “listening” to the cosmos except to the extent that scientists who use this sophisticated form of “stargazing” do not rely on visual study to conduct their work.
Radio Astronomy
To appreciate what is exciting about radio astronomy, first they have to shift how they view astronomy. That is because to professional astronomers, studying the universe is more about
frequencies than it is about visual documentation of phenomenon. This takes us back to Physics 101.
Light, obviously, is the physical phenomenon that empowers our ability to use our visual confirmation technique, e.g. our eyes to appreciate something, in this case the stars. So when they look up at the heavens, they can see the light emitting from a star or reflecting from a planet or moon. In plenty of cases, if they see a far away star, they are actually seeing it hundreds or thousands of years ago because that is how long it takes for that light to cross the universe & be visible in our sky. That alone is a mind blowing idea.
Now light itself is a weird substance. But to our astronomy scientists, light is another energy that exists in a sure frequency. Now, they tend to think of frequencies when they talk about sound waves. In scientific terms light, energy & sound are a few forms of the same thing, frequencies of energy that are emulating from a source.
Now they get to why radio astronomy is so necessary. The range of frequency that light occupies in the massive spectrum of frequencies is little. To put that more bluntly, they can only “see” a tiny part of the universe that is actually there. Now when you look up in the night sky & it is so overwhelming, when you then that they are seeing a tiny amount of what is actually going on up there, again, our minds can get overwhelmed.
For a quantity of us who have heard about radio astronomy, they think of it in terms of “listening” for signs of life in the universe. & yes, SETI, or “the Search for Extra Terrestrial Intelligence” is a part of radio astronomy, albeit a tiny part. But of much greater importance is how radio astronomy has empowered serious astronomers (that is those who get paid to do it) to study stars plenty of light years away, to study black holes which they could never see with our telescopes & to gather research & data about the whole of the universe that otherwise would be impossible to know & understand.
Radio astronomy uses sophisticated sensor equipment to study ALL of the frequencies of energy coming to us from the cosmos. In that way, these scientists can “see” everything that is going on out there & so receive a precise idea of how the stars look, behave now & will behave in the future.
This is important work that is constantly ongoing in the world of astronomy. It is worth keeping up with & learning more about as they have barely scratched the surface in our brief discussion today. But understanding how important radio astronomy is will only deepen & make more meaningful your love & grasp of this massive field of knowledge known as astronomy.