Useless machines are a fun class of devices which typically turn themselves off once they are switched on, hence their name. Even though there’s no real point, they’re fun to build and to operate ...

It can be hard to roll out of bed and get your day started, but a good Bluetooth alarm clock can help make it much more pleasant. The best Bluetooth alarm clocks do so much more than just wake you up ...

The heart of NIST’s next-generation miniature atomic clock ticking at high “optical” frequencies is this vapor cell on a chip, shown next to a coffee bean for scale. The glass cell (the square window ...