Waterfalls have a specific threshold of water flow that must be maintained to preserve their characteristic sound and appearance, according to research that used audio recordings and images to monitor ...

Deep sleep - also known as slow-wave sleep - is crucial for memory, physical renewal and hormonal regulation. But as you get older, it substantially decreases, and scientists believe this contributes ...

They were in a deep sleep, yet sounds, such as a teakettle whistle, somehow penetrated their slumber. The 25 sounds were reminders of earlier spatial learning, though the research participants were ...