Ask Giz: Why Can’t I Get Reception in an Elevator?

Ask Giz: Why Can’t I Get Reception in an Elevator?
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Hi! Welcome to Ask Giz, the series where we listen to your burning questions of the weird and wonderful sort and try to answer them as best as possible.

We’ve already got a pretty nice stockpile of questions to draw from that you, our readers, have submitted, and if you’re yet to submit a question, we invite you to do so here.

Kicking things off, I’ll be answering a question that my editor, Asha Barbaschow, has submitted: Why Can’t I Get Reception in an Elevator?

Thanks for the question, Asha! That’s a good one. It’s a remarkably easy question to answer that involves a really cool sounding scientific concept: The Faraday Cage.

The Faraday Cage is an enclosure that blocks electromagnetic fields. Those are, in basic terms, signals created by electromagnets, like radio waves, Wi-Fi… And phone signals like 4G and 5G.

Put simply, a Faraday Cage is an enclosure made up of a conductive material or collection of materials. You know, like metals. Like what elevators are made of.

How does this happen?

In basic terms, when an electromagnetic field hits the Faraday Cage-like object (elevator) the field is unable to penetrate it, or only penetrates it weakly, as if the enclosed metal is resistant to it, like a force field.

Moreover, elevators are often surrounded by metal in the elevator shaft, adding to the reception resistance of the space. Before you ask, no, this rule doesn’t apply to inbuilt emergency phones in elevators. These are usually wired phones that are able to escape the null signal of an elevator (the wire escapes the elevator, where it meets a transmitter and receiver).

It’s the same logic that goes into an RF receiver or most protective barriers that surround electromagnetic-sensitive equipment.

Conversely, if the elevator is partly made of glass or another non-conductive material, signals can penetrate it, meaning you can browse Twitter in the open-circuit Faraday Cage.

That’s kind of it, really

Wow, easy one off the bat, huh? Thank you Asha! Hope to see more of your questions later on.

Ask Giz is a fortnightly series where we answer your questions, be it tech, science, gadget, health or gaming related. This is a reader-involved series where we rely on Gizmodo Australia’s audience to submit questions. If you have a question for Giz, you can submit it here.