Quiet! I’m listening to the universe
When trying to create images based on faint radio waves from objects in space, stray signals affect the accuracy of the observations. So, how do you block out the noise?
The electromagnetic reverberation chamber at the South African Radio Astronomy Observatory’s (SARAO) office in Mowbray, Cape Town, reminds me of a shipping container. It’s a freestanding, metal box in one of the rooms, and inside, there is a series of metal blades called a stirrer, which rotate to change the distribution of radio waves. On the other wall is an antenna that receives the radio-frequency emissions.
In between is the device being tested. SARAO uses the chamber to test any devices that are going to be used at the MeerKAT radio telescope site in the Northern Cape, around 90km from Carnarvon, which, at over 105 000km[2], is the world’s largest Radio Quiet Zone. Nothing that emits radio frequencies is allowed on the MeerKAT site; this includes cellphones and laptops, and vehicle trackers and voice recorders.
Get 3 months of unlimited access
No credit card. No obligation.