New answers tagged earth
25
votes
Accepted
How high does the ocean tide rise every 90 minutes due to the gravitational pull of the space station?
Bigger than an atomic nucleus but smaller than an atom.
The tidal forces scale as $MR^{-3}$, where $M$ is the mass of the object causing the tides and $R$ would be its separation from the centre of ...
- 158k
3
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What makes the spring equinox happen on october instead of fall on the north hemisphere?
To put it in simple terms: at the equinox, the Earth's axis is halfway in its apparent movement from pointing away from the Sun (northern winter solstice) to pointing towards the Sun (northern summer ...
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5
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When the Earth was spinning faster 4 billion years ago what difference did this make to the temperature of the atmosphere
The study Strong Dependence of the Inner Edge of the Habitable Zone on Planetary Rotation Rate
by Yun Yang et. al. shows that planets previously believed to be too hot for life on their surface may be ...
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6
votes
Accepted
Seasonal variation of aurora and magnetic activity
I had to look this one up. It is a genuine effect, not just an observational bias. The frequency of aurorae has been recorded with automatic cameras on timescales of a decade, showing that the ...
- 158k
0
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Seasonal variation of aurora and magnetic activity
As I have answered here:
What the correlation does show is that there are more observations around the equinoxes, but we need to wonder why such is the case.
and later, with a slight adjustment in ...
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-1
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Why is right ascension measured on a 24 hour scale rather than a 23 hours and 56 minutes scale?
Good point. But who's to say that the 24 hours of RA are hours in normal clock time or sidereal time. At the end of the day its just a conversion of 360 degrees into 24 hours. You can well consider ...
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8
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How to define "Earth" so that it is almost 50% oxygen by weight?
It's in the rocks!
The atmosphere is a tiny fraction of Earth's mass; there's no reasonable way of talking about "the Earth" that ends up with gaseous dioxygen making up even a millionth of ...
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