People have been to space, they have invented antibiotics, you can chat with your friends with the help of your watch! But once elevator doors close, all our gimmicky phones just quit! But the worst thing is that there’s nothing we can do about it.

In most cases, radio waves easily penetrate all kinds of materials, but massive chunks of solid stuff, such as rock or metal can stop them. For example, if you’ve ever driven in a mountainous region, you might have noticed that your phone signal vanished and reappeared again. This mystery has a simple explanation.

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