The next generation of atomic clocks "ticks" with the frequency of a laser. This is about 100,000 times faster than the microwave frequencies of the cesium clocks which are generating the second ...

A radioactive iodine uptake test, or RAIU, is typically performed with a thyroid scan to help determine thyroid health and functioning. The test helps your healthcare provider see how much radioactive ...

The 13-year-old boy came to the clinic with a rapidly ballooning neck. Doctors were puzzled. Testing ruled out their first suspicion. But further tests pinpointed what they—and the boy—had ...