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This thermometer records temperature by listening1 min read

October 7, 2020 < 1 min read


This thermometer records temperature by listening1 min read

Reading Time: < 1 minute

Did you know that objects that are hot not only give out light but also hum? This hum is of such a low frequency that humans can’t hear it, but if we could, it would sound like radio static, explains one of the creators of a special thermometer that can “eavesdrop on objects to take record their temperature”.


This humming happens when the particles in the hot objects move rapidly – the hotter the object, the louder the humming gets. This acoustic thermometer senses just how strong the heat-generated sound emanating from an object is, and then is able to record the object’s temperature.

A tiny silicon nitride sheet inside the device is responsible for the sound waves. This sheet, researches say, is able to transmit sound waves better than air! The silicon nitride vibrates harder when exposed to hotter objects. A laser beam is bounced off the sheet, which lets the researchers track the sheet’s motion, and thus, the temperature of the object.

Learn all about sound waves by watching the video below!