In the Atacama desert of northern Chile, there is a single radio telescope made up of 66 separate antennas, attuned to pick up some of the Universe’s most puzzling signals, digging up the history of the first stars and galaxies and discovering how new astronomical phenomena unfolds, from star birth to solar wind.
At TEDxCharlottesville, Anthony Beasley, director of the National Radio Astronomy Observatory (NRAO), which helps operate this telescope — the Atacama Large Millimeter/submillimeter Array (ALMA) — spoke on how this giant machine works and shared some of the discoveries made possible thanks to ALMA.
“The galaxy is a very strong radio emitter,” Beasley says, explaining how radio telescopes like ALMA pick up these signals and allow astronomers to analyze the complex structures and activities of the Universe, and even observe what the Universe was like in the past, picking up radio signals emitted from the Big Bang.
“Radio telescopes are much like the radios in your car,” he says. “You can turn the dial and you can turn the frequency up … We can continue to turn the dial up. We can start to do observations at frequencies which are perhaps 100 or 1,000 times the frequency of your cell phone. And what happens at that point is … we start to see emission from the thermal properties of materials; we start to see the temperature of gas; we see molecules giving off radio emissions.”
But it isn’t easy to build and operate telescopes that are sensitive enough to provide insight into the Universe’s most subtle functions and activities, that detect temperatures and provide portraits of molecules, Beasley explains. As radio signals move toward Earth, he says, “they’re absorbed and distorted by water vapor and oxygen in the atmosphere.” So, “if you want to build a large telescope to observe at [high] frequencies, you have to somehow get to somewhere that is very high and very dry.”
So, super sensitive, super powerful machines like ALMA require a very particular setting, which is why ALMA is located in a mountainous area of Chile’s Atacama desert, Beasley says. This location, paired with ALMA’s 66 antennae, enables ALMA to reveal intricate details of the Universe’s past as well as its present, shedding light on the lives of stars, galaxies, comets and more, and allowing us to make predictions for its future.
Watch Beasley’s whole talk to learn more:
Insight from the TEDx office — why we like this talk:
The speaker is an expert in his field with extensive experience in this field and with the idea in his talk — how supporting new technology can allow us to learn more about the world and the Universe around us. His talk is well-researched and presented in a manner that is clear, fact-based and accessible to those outside of his field. He presents complex science in a way that is understandable and shows why this science is meaningful and how it is adding to the whole of human knowledge.