Hi I saw a doc on TV that was saying that if the orbit of the earth was to change by a millimeter or so that it would be disastrous for earth. can someone find the link for me?
thanks
virtually yours
The claim is nonsense. The Earth’s orbit is slightly eccentric, which means the distance to the Sun varies by about 5 million kilometres. Over hundreds of thousands of years, the eccentricity can vary considerably due to the tug of the other planets.
This wiki article on Milankovitch Cycles details the ways in which the Earth’s orbit changes, and the effect it has on climate.
I didn’t see it on TV, but in religious-glurge emails, and it was an inch, not a millimeter (because Christians ain’t Godless metric-system-using Yurpeens), but it appears to be a commonly-used proof-for-the-existence-of-God argument.
It looks like in recent years they’ve given themselves a little breathing room by scaling the numbers up a little, so as to more closely resemble the actual Goldilocks Zone.
ETA: 56 posts in eleven years? Are you EVER going to CEASE your INTERMINABLE QUESTIONS? Christ, it’s like being on a road trip across Utah in a station wagon with a six-year old. 
How much energy would be required to do this instantantously?
mmmm, toast links.
An infinite amount
Of course, the inhabitants of Venus and Mars use the fact that their planets are too hot or cold for them to exist as a proof for the non-existence of God.
I think it was saying that if it’s orbit (elliptical notwithstanding) was to be off 1mm or so that things would be a lot different. I.e. it has a perfect elliptical orbit and if this was to go off by that tiny amount it would change everything… maybe exponentially.
virtually yours
Tell us something more about the “documentary.” What was the subject? What channel?
I must assume it was some sort of religious program because the claim has no scientific basis whatsoever. Or else you misunderstood what the claim was.
What would a “perfect elipitcal orbit” even mean? That’s like saying something is a “perfect rectangle”.
Iran this post through Babelfish – it didn’t help! 
That’s because the Tower of Babel was in modern-day Iraq.
But Persia is the next country to the East. It’s not like Iran’s so far away.
If considering the set of all parallelograms, it’s perfectly sensible to refer to some of them as “perfect rectangles”. In the space of all closed curves, only a miniscule subset are “perfect ellipses”.
(of course, the Earth does not have a perfect elliptical orbit, if for no other reason than relativistic precession).
But it’s more than a millimeter.
That’s flocking ridiculous.
Some parts of Iraq are less than a millimetre away from Iran.
I seagulls what you did there.
“Golden Rectangles,” yes. “Perfect rectangles,” no. What would you use for the definition of the term?
In engineering terms, you might speak of a “precise rectangle,” one where the corners are 90 degrees, plus or minus 20 seconds of angular error. That’s probably better than any of us could draw on a piece of paper with ruler and pencil. But in engineering terms, a “perfect rectangle” is unobtainable.