Sunlight is composed of visible, infrared, and ultraviolet light. Ultraviolet and infrared light are portions of the electromagnetic spectrum that are invisible, yet harmful, to the human eye. Exposure to ultraviolet or infrared radiation can cause lasting vision damage, or even blindness, which is ...
Plant and animals often use color to attract attention. The substances responsible for these colors belong to a class of chemical called antioxidants(抗氧化物). Plants make antioxidant to protect themselves from the sun's ultraviolet(紫外线)light. ...
Blue light, part of the visible light spectrum, is emitted from the sun (the most powerful source of blue light), as well as artificial sources, including digital devices. While, even indoors, the sun is the largest source of blue light, blue light is also found in the LEDs of our ...
Infrared radiation is emitted by warm bodies, including living organisms. It's also emitted by dust and gases between stars. Thevisible spectrumis the tiny portion of the spectrum perceived by human eyes. It's emitted by stars, lamps, and some chemical reactions. Ultraviolet radiation isemitted ...
When we say that the energy of light emitted by a material is quantized, what does that say about how light is emitted (or absorbed) by a material? Why is ultraviolet light, but not infrared light, effective in making certain materials fluoresce? At what distance from the S...
How is energy from the Sun distributed around Earth? Solar Radiation: Solar radiation reaches Earth primarily in the visible wavelengths, since that is how it is emitted by the sun (due to the sun's temperature). Ultraviolet and even some shorter wavelengths also reach Earth, though most is ...
The light emitted by the sun consists of three frequency bands of radiation: infrared, visible, and ultraviolet. Of the three, only the ultraviolet is harmful to most humans. Ultraviolet (UV) radiation is further divided into three categories: UVA, UVB, and UVC. UVA radiation penetrates the ...
This radiation, which is constantly emitted by the Sun and other stars, is deadly to living things. If the Van Allen belt did not exist, the massive outbursts of energy called solar flares that frequently occur in the Sun would destroy all life on Earth. The magnetosphere layer, formed by...
We simply don't know yet—but that's one of the questions that NASA launched the Parker Solar Probe to answer. How Do We Study the Sun? Mostly, the Earth's atmosphere blocks out photons with a shorter wavelength than ultraviolet light. This makes it difficult to study the Sun's inner ...
The light emitted has a peak wavelength of about 550 nm, which we perceive as visible white light (or slightly yellowish). According to NASA, if the sun's surface temperature were cooler, about 3,000 C, it would look reddish, like the star Betelgeuse. If it were hotter, about 12,...