Experts disagree on who needs it and when. Here’s what the evidence suggests. By Michelle Crouch Perhaps the most unpleasant part of an eye exam is when the doctor squeezes in the dreaded drops to ...

Eye dilation refers to a widening of the pupils. When doctors dilate the pupils during an eye exam, it typically lasts between 4 and 24 hours. Doctors sometimes use eye dilation drops to dilate a ...

Einstein is most famous for general relativity, which is really a theory of gravity. But his theory of special relativity has been just as important. Special relativity is all about how to interpret ...

Time dilation is real! And anyone who uses a GPS, or the “My Location” option on Google Maps, is making direct use of the fact that time dilation is real. The idea behind time dilation is just as you ...

Vaginismus is a condition where muscles in the pelvic area contract involuntarily during vaginal penetration, causing extreme pain. Consequently, vaginismus can lead to painful sex and trouble ...

We’re all too familiar with the inexorable march of time, but why exactly it flows in one direction remains a mystery of physics. A few years ago Australian physicist Joan Vaccaro proposed a new ...

Time dilation is possibly the weirdest part of Einstein’s Theory of Special Relativity. According to time dilation, the faster you travel, the slower your time moves. But why does this happen? It’s ...

Einstein realized that time is relative and passes at different rates for different people. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Time ...