Category Archives: Phenomena
Encouraging news arrived this week regarding the size of the Southern Hemisphere ozone hole. NASA reported that this year’s ozone hole (which peaked on Sept. 11 at 7.6 million square kilometers) was the smallest since 1988, just years after the problem was first identified.
Though a number of factors contribute to the annual size of the ozone hole, it is beyond doubt that the leading factor is the reduction of chlorofluorocarbons (CFCs), industrial chemicals long used for refrigeration among other things. Continue reading
Lightning is a huge electrical discharge.
Static charges form in a storm composed of ice crystals and liquid water drops. Turbulent winds inside the storm cause particles to rub against one another, causing electrons to be stripped off, making the particles either negatively or positively charged. Continue reading
All the attention of today’s eclipse has raised interest in the sky’s color.
To understand why the sky is blue, we need to understand a little about light. Light is a form of electromagnetic energy. This form of energy does not need matter to propagate. Continue reading
The sun appears to rise in the east and set in the west. This happens because of how the Earth spins as it orbits the sun. If you are in space and look down on the North Pole, the Earth … Continue reading
The classic rainbow is a single, bright, colored arc. Red is the outermost color of this arc, and violet is always the innermost color.
On occasion, you may have seen two rainbows at once. The lower rainbow is the primary rainbow and the higher, fainter, colored arc is the secondary rainbow. The color sequence of the secondary rainbow is opposite to the primary; red is on the inside of the arc and violet on the outside. Continue reading