Psychology & Psychiatry

How to make your workplace a healthier one

(HealthDay)—Even if you love your job, your workspace might not love you back. Because people may spend 40 or more hours on the job, often at a desk, all that exposure to less-than-inspiring surroundings can negatively ...

Oncology & Cancer

Stay sun safe for your DNA

Important parts of our DNA don't get easily repaired after being exposed to sunlight, cancer scientists at the University of New South Wales (UNSW) have shown.

Psychology & Psychiatry

Got the winter blues? All about seasonal affective disorder

If winter days get you down, you're not alone. You may have seasonal affective disorder, a type of depression triggered by the change of seasons. People with this disorder tend to feel depressed in the fall and winter, when ...

Pediatrics

Season of conception may affect fetal brain growth

(HealthDay)—Children conceived during the winter are more likely to have learning disabilities, and a mother's exposure to sunlight may play a role, a new study suggests.

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Sunlight

Sunlight, in the broad sense, is the total spectrum of the electromagnetic radiation given off by the Sun. On Earth, sunlight is filtered through the atmosphere, and the solar radiation is obvious as daylight when the Sun is above the horizon. Near the poles in summer, the days are longer and the nights are shorter or non-existent. In the winter at the poles the nights are longer and for some periods of time, sunlight may not occur at all. When the direct radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and heat. Radiant heat directly produced by the radiation of the sun is different from the increase in atmospheric temperature due to the radiative heating of the atmosphere by the sun's radiation. Sunlight may be recorded using a sunshine recorder, pyranometer or pyrheliometer. Sunlight takes about 8.3 minutes to reach the Earth. The World Meteorological Organization defines sunshine as direct irradiance from the Sun measured on the ground of at least 120 watts per square metre.

Direct sunlight has a luminous efficacy of about 93 lumens per watt of radiant flux, which includes infrared, visible, and ultra-violet light. Bright sunlight provides luminance of approximately 100,000 candela per square meter at the Earth's surface.

Sunlight is a key factor in photosynthesis, a process crucially important for life on Earth.

This text uses material from Wikipedia, licensed under CC BY-SA