Obstetrics & gynaecology

Menopause and migraines: New findings point to power of prevention

For middle-aged women plagued by migraines, or hot flashes and night sweats, another worry may linger in the backs of their minds: whether these experiences have set them up for a heart attack, a stroke or another cardiovascular ...

Health

Expert explains how shift work affects your sleep

All life on Earth is affected by the day-night cycle resulting from the planet's rotation. In line with this, humans are naturally awake during daylight hours, and sleep at night when it is dark. Being awake during the day ...

Health

Sleepless cities: How urban noise and light keep us up at night

Living in cities that never sleep has its price: inhabitants are getting less, worse quality, sleep. We cannot forget that sleep, though often undervalued, is a fundamental part of staying in good health. It is well established ...

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Night

Night or nighttime is the period of time when the sun is below the horizon. This occurs after dusk. The opposite of night is day (or "daytime" to distinguish it from "day" as used for a 24-hour period). The start and end times of night vary based on factors such as season, latitude, longitude and timezone.

At any given time, one side of the planet Earth is bathed in light from the Sun (the daytime) and the other side of the Earth is in the shadow caused by the Earth blocking the light of the sun. This shadow is what we call the darkness of night.

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