The force that causes winds, or any freely moving object or fluid, to deviate to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, as a result of the earth's rotation.

1. A phenomenon seen as a flash of sunlight shines down a lunar valley during a total solar eclipse.
2. An effect created as the total phase of a solar eclipse is about to begin, when the last Baily's bead, a remaining bit of phosphere, glows so intensely by contrast with the sun's faint corona that it looks like the jewel on a ring.

It also refers to the equivalent phase at the end of totality.

1. Change in frequency of sound or light waves caused by the relative motion of the source and the observer.
2. The shift of spectral lines due to a body's motion toward or away from an observer.

Astronomers can tell by the Doppler effect if a distant star is moving toward or away from us.

3. A perceived change in the frequency of a wave as the distance between the source and the observer changes; for example, the sound of a siren on a moving vehicle appears to change as it approaches and passes an observer.
4. Etymology: named after Christian J. Doppler (1803-1853), an Austrian physicist and mathematician who first described the principle known as the Doppler effect in 1842.

Doppler observed that the frequency of light and sound waves is affected by the relative motion of the source and the detector.

Another example is that of a train which approaches an observer, and a lower pitch after it passes by. The Doppler effect applies to all types of waves, including light.

The trapping of infrared radiation from the surface of a planet by a dense atmosphere, opaque to heat radiation.

This effect occurs on Venus and on Earth.

An alteration in behavior or physiology within a species brought about by signals that are directed in neither space nor time.

A simple example is social facilitation, in which an activity increases merely from the sight or sound (or other form of stimulation) coming from other individuals engaged in the same activity.

The phenomenon that occurs when photons, the "particles" in a beam of light, knock electrons loose from the atoms they strike.

When this property of light is combined with the properties of semiconductors, electrons flow in one direction across a junction, setting up a voltage.

With the addition of circuitry, current will flow and electric power will be available.

1. The shortening of a sunspot lying close to the edge of the sun's visible disk.
2. An effect in which the penumbra of a sunspot appears narrower in the direction toward the sun's center than in the direction toward the sun's limb.

In 1769, a Scottish astronomer named Alexander Wilson noticed that the shape of sunspots noticeably flattened as they approached the Sun's limb due to the solar rotation.