Search results
Results From The WOW.Com Content Network
The spectrum does not contain all the colors that the human visual system can distinguish. Unsaturated colors such as pink, or purple variations like magenta, for example, are absent because they can only be made from a mix of multiple wavelengths. Colors containing only one wavelength are also called pure colors or spectral colors. [8] [9]
The four pigments in a bird's cone cells (in this example, estrildid finches) extend the range of color vision into the ultraviolet. [1]Tetrachromacy (from Greek tetra, meaning "four" and chroma, meaning "color") is the condition of possessing four independent channels for conveying color information, or possessing four types of cone cell in the eye.
On Mars, the setting Sun appears about two-thirds the size it does from Earth, [21] due to the greater distance between Mars and the Sun. The colors are typically hues of blue, but some Martian sunsets last significantly longer and appear far redder than is typical on Earth. [22] The colors of the Martian sunset differ from those on Earth.
The northernmost town in America is about to experience several weeks of darkness. After getting 30 minutes of daylight, the town of Utqiaġvik, Alaska – formerly known as Barrow – saw its ...
The Sun is the star at the center of the Solar System.It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light and infrared radiation with 10% at ultraviolet energies.
Many rainbows exist; however, only one can be seen depending on the particular observer's viewpoint as droplets of light illuminated by the sun. All raindrops refract and reflect the sunlight in the same way, but only the light from some raindrops reaches the observer's eye.
This effect is more pronounced closer to the poles, where the Sun rises at the vernal equinox and sets at the autumn equinox, with a long period of twilight, lasting for a few weeks. [citation needed] The polar circle (at 66°33′50.3″ north or south) is defined as the lowest latitude at which the Sun does not set at the summer solstice.
At the equator, civil twilight can last as little as 24 minutes. This is true because at low latitudes the Sun's apparent movement is perpendicular to the observer's horizon. But at the poles, civil twilight can be as long as 2–3 weeks. In the Arctic and Antarctic regions, twilight (if there is any) can last for several hours.