Diseases, Conditions, Syndromes

During a heat wave, high indoor temperatures can also prove dangerous

During hot weather—like the wave of 90-plus-degree days that Philly will experience this week—most of the public's attention is focused on skyrocketing outdoor temperatures that can cause serious medical complications ...

Health

Baby on board? Don't let the heat put you in peril

With summer temperatures soaring, pregnant women need to be extra cautious to avoid heat-related health issues. The body's natural cooling mechanisms are already working overtime during pregnancy, making it more difficult ...

Health

Wildfire smoke and understanding the health risks

With wildfires becoming more frequent and extensive in Canada, it's important for people to understand the health risks of wildfire smoke. An article in CMAJ (Canadian Medical Association Journal) aims to provide information ...

Gastroenterology

Findings from studies presented at Digestive Disease Week

Digestive Disease Week, the annual meeting sponsored by the American Association for the Study of Liver Diseases, American Gastroenterological Association, American Society for Gastrointestinal Endoscopy, and Society for ...

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Earth's atmosphere

The Earth's atmosphere is a layer of gases surrounding the planet Earth that is retained by the Earth's gravity. It has a mass of about five quadrillion metric tons. Dry air contains roughly (by volume) 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide, and trace amounts of other gases. Air also contains a variable amount of water vapor, on average around 1%. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night.

There is no definite boundary between the atmosphere and outer space. It slowly becomes thinner and fades into space. An altitude of 120 km (75 mi) marks the boundary where atmospheric effects become noticeable during atmospheric reentry. The Kármán line, at 100 km (62 mi), is also frequently regarded as the boundary between atmosphere and outer space. Three quarters of the atmosphere's mass is within 11 km (6.8 mi; 36,000 ft) of the surface.

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