Out of 1000+ questions on physics stack exchange, only 7 have a -4 or worse count (this link is temporary):

One of these is a question I asked about asteroids and life on the planet:
"Could life survive if the earth's axis were knocked 70 degrees by an asteroid collision?" -4
Could life survive a pole shift caused by an asteroid collision?

Evidently four people voted it down and none up and I don't have a clue why. It's a basic physics question, it can be answered with a simple calculation, and it's of interest to the general public. Comments on the question are:

Some people have evidently never played with a gyroscope or tried to turn a spinning bicycle wheel out of plane with their hands. What mechanism is proposed to damp the ferocious precession that would be the inevitable aftermath of twisting the axis around like that? Bah! Humbug! – dmckee 2 days ago

What sort of asteroid could knock Earth's axis off by 70 degrees without ripping the planet to shreds, for that matter!? – Noldorin♦ yesterday

@Noldorin: Yeah. I started trying to estimate the energies involved, but floundered when I realized there was no impulse-like way to get from there to here. – dmckee yesterday

Some very simple calculation would answer this question. – Georg yesterday

Eventually, I answered my own question with the calculation I outlined.

For reference, the only questions with a lower rating (i.e -5) are questions which, one way or another, do not make sense:

"If energy in a flat space is zero, are we saying that a flat space is isolated?" -5

"Why is there something rather than nothing? [closed]" -5
Why is there something rather than nothing?

So I'm wondering. Anyone have a clue?

There are three other asteroid / meteor questions. This one also has to do with a life endangering asteroid: "Relativistic Object Impacts the Earth" +2
Relativistic object impacts the earth

The other questions: "Orbital mechanics of Dragon's Egg" +3 Orbital mechanics of Dragon's Egg

"What would be the real-world implications of the Kessler Syndrome?" +0 What would be the real-world implications of the Kessler Syndrome?

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    $\begingroup$ Perhaps if the title of your question was reworded to "By what amount would the Earth's axis be shifted due to an asteroid collision of so-and-so magnitude?". As it stands you're asking if life would survive after a 70 deg shift. Well, it probably would, but not in a form we see today. $\endgroup$
    – Deepak Vaid
    Commented Feb 3, 2011 at 3:05
  • $\begingroup$ No, it definitely wouldn't. Not a chance. If you'll check the answer I gave as a calculation, the effect would require a 4000km asteroid which would provide kinetic energy to the earth's surface equal to one million hydrogen bombs (each of 1 megaton rating) being set off on each square km of the planet's surface. That's 600 million million bombs. No, life does not survive that, at least not on the surface. $\endgroup$ Commented Feb 3, 2011 at 3:15
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    $\begingroup$ I'm not arguing with you. I didn't downvote your question either. Its just a suggestion. $\endgroup$
    – Deepak Vaid
    Commented Feb 3, 2011 at 3:26
  • 2
    $\begingroup$ Wow. I think people should really cool off with the comments. $\endgroup$
    – Sklivvz
    Commented Mar 20, 2011 at 17:57

4 Answers 4


I think that it was a big mistake to begin your question with a ridiculous theory of your fellow. Even worse, the question itself is just the last two lines and the rest of the text is some nonsense that I would rather not read and that is why I downvoted your question.

Update: even worse, some naive person would read it and then remember that he saw a theory at Physics.SE about how oil was formed because of the asteroid impact.


I didn't vote on this question of yours - but yes, it's mostly because I hadn't previously read it.

To make such a change, you need a nearly Moon-sized asteroids, and there aren't any in the Solar System, especially not those that are on collision course with Earth. Moreover, changes of some poles would clearly be the last worry if we were going to collide with a Moon-sized objects. Moreover, all the questions you are asking about this insanely unlikely scenario can be easily calculated by elementary mechanics. People just didn't think it was a question worth their time.


I am no expert, but it strikes me as more of a science fiction "what if?" than an actual hard Physics question.

See https://physics.stackexchange.com/faq#dontask and in particular

We are being asked an open-ended, hypothetical question: “What if ______ happened?”

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    $\begingroup$ For "what if" questions with +10 or higher ratings, see "How long a straw could Superman use?", "How fast a (relatively) small black hole will consume the Earth?", "What experiment would disprove string theory?", "What if the universe is rotating as a whole?", "What is the fallacy in this infinite motion machine?", "In general what will holding an anti-hydrogen atom for more than a 1/10th of second allow scientists to discover?". For evidence that this sort of question is "physics" see many arXiv articles such as arxiv.org/abs/1010.5125 $\endgroup$ Commented Feb 3, 2011 at 3:21
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    $\begingroup$ @Carl: At least the anti-hydrogen and disproof of string theory questions are current issues in physics and the infinite motion machine is a needs re-re-re-debunking even fifteen minutes or so. Crowd-sourced moderation and evaluation will suffer from inconsistencies. That's part of its nature. You seem to have gotten the raw end of that stick this time around. $\endgroup$ Commented Feb 3, 2011 at 19:43

I didn't vote it down, nor did I vote to close.

But the proposed scenario is obvious tripe, because any impulse-like event that caused a large change in angular momentum like that would leave the body with a fearsome precession. Jumping Jebus, man! You don't even have a pure torque (what the engineers call a "couple") in the problem, so there'd be a huge transfer of linear momentum as well.

Your BOTE calculation is a brave attempt, but it doesn't model the proposed physics because it doesn't end with Earth having a small precession. That's why I didn't go ahead with a similar calculation.


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