Halley's Comet
In the 1700s the astronomer Edmond Halley studied historical records of the appearance of ...
Everyone dreams several times a night. These dreams occur in a stage of sleep known as R.E.M., which stands for "rapid eye movement." R.E.M. is the fifth stage of sleep. During the first four stages, our minds gradually slow down. By stage four, our minds produce only their slowest waves, known as delta waves. However, after about ninety minutes of sleep, we reach R.E.M., characterized by mental activity almost identical to that of our minds when awake. Heart rate and breathing become more rapid, and blood pressure increases. Our dreams could cause significant physical activity during this stage if it were not for the production of glycine, which renders the body completely paralyzed during R.E.M. sleep. While researchers present differing theories regarding the role of dreams in our lives, it has been well-documented that those who are continually disrupted from R.E.M. sleep display higher incidences of irritability and depression.
In the 1700s the astronomer Edmond Halley studied historical records of the appearance of ...
Many modern medicines originally came from plants. Aspirin was first made from the willow ...
After a cool spring rain, step outside and you might see a beautiful rainbow. Rainbows sho...