One ruler is cooled to liquid nitrogen temperature and another is left at room temperature. The two rulers are compared to show that the cooled ruler has contracted. This demonstration requires ...

This summer has been hot—one of the hottest on record—and it's probably just going to keep getting hotter. I feel like we are getting to the point where air-conditioning isn't just something nice to ...

When a laser beam is incident on a narrow opaque object such as a fine wire or a strand of hair, the resulting diffraction pattern is similar to the diffraction pattern of a slit of the same width as ...