You know, mistakes like that is why I wish I had a calculator with a registry tape. I'm curious what numbers I punched in to get 1/6th mass.
If the World Stopped Spinning?
- Thread starter pharaohmoan
- Start date
John Connellan
Valued Senior Member
Many people have the idea in their heads that the centripetal acceleration of an object on the earth's surface is huge since they are travelling at a linear velocity of about 1600 kph. Surely we should be flung off the earth if it suddenly stopped spinning.
However, they forget to remember that we are a long way from the center of this rotation. Because the radius of the earth is so large, the angular velocity of objects on the surface is quite small and the resulting centripetal acceleration is also small - much smaller than g.
Alright, let's go with that map that was supplied of the non-spinning Earth scenario from the article (page 1); an equatorial continent, with oceans at each pole. Given that the atmosphere will stay in place (because the Earth's gravity will not change) the sun's heat will be shifted around by the winds.
Although there will be a significant increase in the temperature on one side of the planet and a corresponding reduction on the 'night side' of Earth, the heat-transfer by wind will ensure that these extremes will not as extreme as might be expected.
Assuming that the Earth still rotates on its usual angle and the Arctic and Antarctic Circles still exist, these areas (the new polar seas) will be the only places where people can stay living on the surface in reasonable comfort--presumably in floating communities on the polar oceans, or around the coasts thereof. The other alternative are subterranean communities on the continents in either the cold or warm hemispheres.
Although there will be a significant increase in the temperature on one side of the planet and a corresponding reduction on the 'night side' of Earth, the heat-transfer by wind will ensure that these extremes will not as extreme as might be expected.
Assuming that the Earth still rotates on its usual angle and the Arctic and Antarctic Circles still exist, these areas (the new polar seas) will be the only places where people can stay living on the surface in reasonable comfort--presumably in floating communities on the polar oceans, or around the coasts thereof. The other alternative are subterranean communities on the continents in either the cold or warm hemispheres.
John Connellan
Valued Senior Member
What angle is this? Didn't you say that the earth would not be rotating? Do you mean that it rotates once a year so keeping the same side towards the sun at all times?
Anyway, the old polar regions are not the only places we could live. We could live aywhere around the new north-south equator without radiation being excessively high. The weather would, however, still be extreme to say the least and I wouldn't like to be caught in one of those strong heat transfer winds!
Woops...my apologies--I should have made that clearer.
I'm assuming that the angle of rotation of the Earth will remain the same even when the planet has been trapped in a non-rotating mode. I must agree that the heat-transfer winds would be savage. I suggest that while we could live in the most extreme environments, the most comfortable place would be the high latitudes of each hemisphere.
John Connellan
Valued Senior Member
Although, to be fair, I don't think we could live on a continental area on the dark side (if the earth kept the same side towards the sun throughout the year).
If temperatures often get to -80 C in an Antarctic winter, you can only expect temperatures to drop to at least -140 C over there
Imagine being able to experience that, wonder what kind of cloths you would need!
There would be certain advantages to underground cities in such a situation...
Even so, where would you get the sunlight you need?
Quite simply yes everything would die.
First of all the earths magnetic field would collapse. This is due to the dynamo effect present in the earths core. If the earth stops spinning, so does the core. When the core stops spinning the magnetic field collapses and the earth is barbequed by the sun.
Second the moon would not be able to hold a stable orbit around the earth. The planets hold their orbits due to the fact that the sun rotates creating a gravity well. If the earth stops spinning the moon will either:
1. spiral into earth and crash into it.
2. spiral out of orbit.
Third the earth would lose it's atmosphere. In the NGEO documentary they claim that the atmosphere would settle on the poles. Untrue. As the earth stops spinning, it would slowly lose part of it's gravitational field and even a small change in that would cause the outer atmosphere to bleed off into space.
Not that any of this is even remotely possible in the realm of physics, but that is what would happen.
First of all the earths magnetic field would collapse. This is due to the dynamo effect present in the earths core. If the earth stops spinning, so does the core. When the core stops spinning the magnetic field collapses and the earth is barbequed by the sun.
Second the moon would not be able to hold a stable orbit around the earth. The planets hold their orbits due to the fact that the sun rotates creating a gravity well. If the earth stops spinning the moon will either:
1. spiral into earth and crash into it.
2. spiral out of orbit.
Third the earth would lose it's atmosphere. In the NGEO documentary they claim that the atmosphere would settle on the poles. Untrue. As the earth stops spinning, it would slowly lose part of it's gravitational field and even a small change in that would cause the outer atmosphere to bleed off into space.
Not that any of this is even remotely possible in the realm of physics, but that is what would happen.
Possibly.
This is wrong.
Gravity is not caused by spin, but by mass. Non-spinning objects (e.g. you) still create and respond to gravity.
No. The Earth's gravitational field is unaffected by spin. Only mass counts.
eclaire291
Registered Member
Possibility
I know that this question was posed as a hypothetical, but I'm just wondering if it would be possible for this to ever really happen? Are there any known planets that do not spin? Sorry, I just got to wondering after watching an episode of "Aftermath" on National Geographic in which the Earth stopped spinning.
I know that this question was posed as a hypothetical, but I'm just wondering if it would be possible for this to ever really happen? Are there any known planets that do not spin? Sorry, I just got to wondering after watching an episode of "Aftermath" on National Geographic in which the Earth stopped spinning.
Yes. Planets deform when they spin due to the tides caused by the primary and by any moons. This requires energy, thus energy is lost constantly. This means the planet slowly slows down - although this will take billions of years.
Pluto and Charon have become "tidally locked" - they have both been slowed so much by tides that they no longer spin relative to each other. (They do, however, spin around a common center, so they still spin as a system at about once every six days.) If this happened to the Earth the length of the day would become 28 24 hour days long.
It would certainly turn the Earth into an interesting place.