Ten things you don’t know about the Earth - Phil Plait at Bad Astronomy considers the following propositions:
1) The Earth is smoother than a billiard ball.
2) The Earth is an oblate spheroid
3) The Earth isn’t an oblate spheroid
4) The Earth is not exactly aligned with its geoid
5) Jumping into hole through the Earth is like orbiting it (including, digging to China)
6) The Earth’s interior is hot due to impacts, shrinkage, sinkage, and radioactive decay
7) The Earth has at least five natural moons. But not really
8) The Earth is getting more massive
9) Mt. Everest isn’t the biggest mountain, and
10) Destroying the Earth is hard
I'm particularly comforted by that last item.
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Today we celebrate the 40th anniversary of Earth Day, an environmental "teach-in" first promoted by Senator Gaylord Nelson in 1970.
Every introductory astronomy text and most intro physics texts talk about tides. The usual explanation is something along the lines of:
Time for another Fermi problem. There was a recent story in Science News that talked about the effects of the Chilean quakes on the Earth's rotation.
I'm particularly comforted by that last item. Why? Are you planning on hanging around for a while, geologically speaking?
Planet Earth is a dangerous place, nobody gets out of here alive!
Any Australian who finds something more important than sport is an enigma to me (I may not be Australian, but I have a good sense of what goes on there)..... all the more intriguing.... will check back regularly. And I have a hard time swallowing numbers 1 and 2 and 3. :o)
"Lighten up, Francis."
Re #5: Doesn't that neglect the fact that the Earth is rotating, but that you won't be rotating with it?
Re #10: Bonus factoid, especially for those who think that relativistic effects are negligible in situations we usually encounter: What is the mass deficit represented by the gravitational binding energy of the earth? (ie. How much less does the Earth mass than all the bits would after Phil has finished destroying it?) I calculated this once, and I forget the answer except that it had a surprisingly impressive number of digits.
Yay, I knew two!! #9, thanks to the BBC's Planet Earth series. There are plenty of larger-than-everest mountains in the oceans!
As for #10, I remember reading this article a while ago - Earth may be really hard to destroy, but if we ever decide to go about it, there's your instruction manual.
I notice he didn't dare touch the "women are from Venus, men are from Mars" hypothesis. Nor did he address the fact that Earth isn't made of earth. I'm starting to think Phil isn't as "Bad As-" he could be!
#6: to be more precise, if one astronaut circles the planet at ground level (assume no atmosphere) on a meridian, and another, at the same time, jumps in a hole along the North-South diameter, then they will have the same period around the planet, and thus will be able to play chess together, one move each time they meet (at each pole alternatively).