We never measure time directly; instead, we use clocks to measure moments in time, meaning “time” is just a measurement of ...

While new optical illusions go viral all the time, here are some of the most famous illusions that have kept us scratching our heads for years.

One of the frustrations of getting older is that some early memories seem to dim and fade with time. Scientists call these ...

Warning: This optical illusion might give you a headache. At a glance, the swirls of tilted black-and-white squares create the perception of a spiral. Look more closely and you realize that the ...

Have you ever looked at the nighttime horizon and gasped at the sight of a spectacularly large moonrise? Typically, if you glance up at the sky hours later, the Moon will seem to have shrunk. Dubbed ...

Two NASA astronauts had some fun during the ISS' capture of a robotic cargo spacecraft on April 13, pretending to hold onto ...

Diagnosing someone with autism spectrum disorder (ASD) requires a whole host of different inputs, and various involved evaluations. But there may be one simple test that could help, and all it ...