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Exposure of skin to ultraviolet radiation from sunlight presents both positive and negative health effects. On the positive side, UV exposure enables the synthesis of vitamin D3, which is essential for bone health [1] and potentially plays a role in inhibiting certain cancers. [2][3] While vitamin D can also be obtained through dietary ...
Eunice Newton Foote (July 17, 1819 – September 30, 1888) was an American scientist, inventor, and women's rights campaigner.She was the first scientist to confirm that certain gases warm when exposed to sunlight, and that therefore rising carbon dioxide (CO 2) levels could increase atmospheric temperature and affect climate, a phenomenon now referred to as the Greenhouse effect.
The ultraviolet index, or UV index, is an international standard measurement of the strength of the sunburn -producing ultraviolet (UV) radiation at a particular place and time. It is primarily used in daily and hourly forecasts aimed at the general public. The UV index is designed as an open-ended linear scale, directly proportional to the ...
The Yarkovsky–O'Keefe–Radzievskii–Paddack effect, or YORP effect for short, changes the rotation state of a small astronomical body – that is, the body's spin rate and the obliquity of its pole (s) – due to the scattering of solar radiation off its surface and the emission of its own thermal radiation. The YORP effect is typically ...
Micrograph of the epidermis, with melanin labeled at left. Melanin (/ ˈmɛlənɪn / ⓘ; from Ancient Greek μέλας (mélas) 'black, dark') is a family of biomolecules organized as oligomers or polymers, which among other functions provide the pigments of many organisms. [1] Melanin pigments are produced in a specialized group of cells ...
Solar activity and climate. Solar irradiance (yellow) plotted with temperature (red) since 1880. Patterns of solar irradiance and solar variation have been a main driver of climate change over the millions to billions of years of the geologic time scale. Evidence that this is the case comes from analysis on many timescales and from many sources ...
Melanomas are the most aggressive. Signs include a mole that has changed in size, shape, color, has irregular edges, has more than one color, is itchy or bleeds. [3] More than 90% of cases are caused by exposure to ultraviolet radiation from the Sun. [4] This exposure increases the risk of all three main types of skin cancer. [4]
The effects of spaceflight on the human body are complex and largely harmful over both short and long term. [1] Significant adverse effects of long-term weightlessness include muscle atrophy and deterioration of the skeleton (spaceflight osteopenia). [2] Other significant effects include a slowing of cardiovascular system functions, decreased ...