Jumping Starlight

'Twinkle, twinkle, little star, how I wonder what you are,' says the song by Jane Taylor. But stars don’t really twinkle; their light reaches the earth in a steady way. Why then do we see them flickering around in the sky? The answer is in the atmosphere. ...

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Smallpox, Chickenpox . . . Monkeypox?

This past summer a few people in the midwest came down with monkeypox, a viral disease related to smallpox but less infectious and a lot less deadly to humans. Oddly they all seem to have caught the ... Continue reading


What Is Narcolepsy?

Narcolepsy is a sleep disorder than affects about 1 of every 2000 people worldwide. It usually starts in the teens or twenties, but it may begin in childhood. People who have it fall suddenly and ... Continue reading


What Is A Coccolithophore?

Like any other type of phytoplankton, coccolithophores are one-celled marine plants that live in large numbers throughout the upper layers of the ocean. Unlike any other plant in the ocean, ... Continue reading


How To Calculate The Area Of A Cylinder

Understanding how to find the area of a cylinder is easy if one first visualizes the cylinder and breaks its surface down into component pieces. To do this, first take a good look at the most common ... Continue reading


Brain Waves

BrainWavesYour brainwaves normally vary from a low vibrational state of about one Hz ('Hertz,' or vibrations per second) to a high of about 30 Hz. The highest-frequency vibrations, ranging from about 13 to 30 Hz, are called beta waves. When your brain is in a beta state, it's in a high state of alertness. Alpha waves are somewhat slower, from 8 to 13 Hz. If your brain moves into the alpha range, you're still awake and alert, but more relaxed. As your brain moves into the theta range, from about 4 to 7 Hz, you're entering the realm of sleep. It's in the theta range that you dream. Delta waves are the slowest, from about 0.5 to 4 Hz. That's the realm of deep sleep, which your brain needs to replenish itself for the activity of another day. Even in its low-frequency delta state, your brain is still active. What's it doing?

One recent theory about delta sleep is that it's a period when your brain is carrying on a quiet internal dialog, during which the hippocampus (a brain structure crucially involved in learning and memory) sorts through the day's flotsam and jetsam of experiences, selecting out the important lessons from the day and relaying them to the cortex. Then, when your brain moves into the theta state of REM sleep, it practices and rehearses its newly-learned lessons in dreams.