John Carlsen has more than a decade of experience testing and reviewing home tech products, with a major focus on smart home security. He earned his BS in journalism from Utah Valley University. In ...

When I say jump, your iPhone can tell you how high.

A barometer is the instrument we use to measure air pressure. At the bottom of this post, I’ll explain why air pressure is critical in forecasting the weather. Cut the neck off the balloon and stretch ...

Nicolas Fortin, an instrument maker in Paris in the early nineteenth century, introduced a mercury barometer with a glass and leather cistern so designed that the barometer could be safely moved from ...