Why is it Dark at Night?
Have you ever wondered why you look up and see a dark sky at night? Help share science with the world: http://translate.minutephysics.com Subscribe to MinutePhysics! MinutePhysics is on Google+...
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Why is the sky dark at night?You might think the answer is obvious - the sun isn't up! But the only reason the skylooks blue during the day is that sunlight scatters off of the atmosphere - if we didn’thave an atmosphere (like on the moon), the sky would always be dark, even when the sunis shining. So let’s rephrase the question - why is space dark?I mean, space is full of stars - countless stars which are all about as bright as thesun, and in an infinite eternal universe, no matter what direction you picked, if youlooked far enough in that direction, you would see a star or galaxy. So the whole sky shouldbe as bright as the sun, night and day!And since it's not, does the darkness of the night sky mean that there's some distanceaway from ...
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Why is the sky dark at night?You might think the answer is obvious - the sun isn't up! But the only reason the skylooks blue during the day is that sunlight scatters off of the atmosphere - if we didn’thave an atmosphere (like on the moon), the sky would always be dark, even when the sunis shining. So let’s rephrase the question - why is space dark?I mean, space is full of stars - countless stars which are all about as bright as thesun, and in an infinite eternal universe, no matter what direction you picked, if youlooked far enough in that direction, you would see a star or galaxy. So the whole sky shouldbe as bright as the sun, night and day!And since it's not, does the darkness of the night sky mean that there's some distanceaway from ...
