If the world was to stop spinning..

[doomey!]

would it be possible to still live on the earth? If so where?

[sammd]

I'm not sure about the whole stopping spinning bit (would this affect gravity?) but surely everyone would want to migrate as it moves around the sun to keep on the side facing it, so they can grow crops, etc. I would've thought it'd be more difficult to provide for the whole world's population.

[Robert G]

If Earth stopped spinning on its axis, pretty well all parts of its surface would receive sunshine for half of each year, and be in darkness for half the year. This is because Earth would still orbit the sun once a year.

The exception to this would be at the 'top' and 'bottom' (not the north and south poles, though, because the Earth's axis is titled relative to its orbital plane) where a half-sun would be visible on the horizon all the time.

The moon would still orbit Earth, and so tides would still occur.

The Earth's gravity would remain the same.

In partial answer to sammd's concern about growing crops, one idea might be to create enormous floating 'islands' which could be propelled around the oceans so as to always be in sunshine.

A fascinating question, doomey, and I look forward to reading other ABers' thoughts on this.

[Robert G]

Hm. I think I used the word 'sunshine' rather optimistically. I deliberately didn't use 'daylight' because days, as we know them, would not occur. A new day would be half a year, of course.

Perhaps 'half-yearlight' would be correct, thus allowing the possibility of cloudy periods.

the Earth's air currents (and sea currents?) would change, I think, which would bring about big changes in the weather.

[newtron]

Weather patterns would change dramatically due to large energy gradients between the side of the earth that is facing the sun and the side opposite the sun. Presently, the energy gradient exists mailnly between the area around the equator where the energy per unit area brought by the sun is high and the higher lattitudes or polar reagons where the energy per unit area is much smaller. Energy gradients between one side of the earth and the other are probably low due to the spinning of the earth , which spreads the energy around the earth on a relatively small time scale. If the earth stopped spinning, one day would be effectively one year long, significantly increasing this time scale. Therefore large energy gradients would form and probably be the dominant force that controls weather patterns.

[sammd]

Would the side facing away from the sun for half a year get extremely cold? If such large energy gradients existed problems may occur with growing crops on the side that has just been in the dark (perhaps if cold, then covered by ice which would take time to melt?)...so as Robert G suggested, large floating rafts could be the only way...?

[Robert G]

And so the weather would have greater extremes. At the top and bottom it would never get very hot but neither would it get very cold. Half way down (or up) - not the same as what we now call the equator - the summer would be extremely hot and the winter would be extremely cold. Probably the land would become barren very quickly and support no vegetation. Animal life, including humans, would survive only by migrating away from this central band region unless living within protective structures, including underground. Everywhere there would probably be very high winds which would continually erode the soil. I think the prospects for all life would be bleak.

[sammd]

Following on...would it make a difference if the speed of spin changed or direction of spin changed?

[JudgeJ]

First of all, beware what Robert G says about the tides. It is true that we would still get tides, but not twice daily as now. The tidal �stretching� which the earth experiences at present occurs because of the earth�s rotation. The moon�s orbit around the earth actually displaces the tides from twice in twenty four hours to twice in (roughly) 24 hours 50 minutes. So high tide appears almost an hour later every day. This is because, in the period of 24 hours the moon has �moved� in its 28 day orbit around the earth.

If the earth were to stop spinning all that would be left to cause the tides (ignoring the weaker effect of the Sun for now) is the moon�s orbit around the earth, and we would experience two high tides every 28 days. This alone would have a profound effect on the earth and the life upon it.

If the earth�s spin were to change direction this too would have far reaching effects. Among other things, the Sun would rise in the west and set in the east. The tides would be effected (we would get two high tides every 23 hours and ten minutes and they would appear to move in the opposite direction around the earth). The weather would also be profoundly effected because of the coriolis effect. This is the effect that the rotating earth has upon the winds.

The earth�s speed of rotation is actually diminishing very slowly but very surely. This is caused by the �tidal drag� exerted by the moon. This has the effect of lengthening the day. This same force is also causing the moon�s period of orbit to decrease. Eventually the earth and moon will become �tidally locked� with the same part of the earth always facing the moon. Then the tides will be governed only by the much smaller influence of the sun.

All in all, best to leave things as they are!

[Lollyhoney]

I'm sure someone once told be that if the world stopped spinning suddenly we'd all fly off but the could've been winding me up!!

[Toureman]

The earth spins at just over 1000mph at the equator, if the earth suddenly stopped everything on the earth would still keep moving at 1,000mph and at slower speeds as you move away from the equator.

This would not be very nice!

[doomey!]

yes but "shirley" with evolution, we could get used to it, no?

[tommy666]

takes way to long to evolve something that would make any kind of difference. millions of years to evolve, and maybe more if you are talking about some huge evolution which would mean none of the problems would effect us. i bet all life on earth would stop existing before any animal could get a chance at evolving

[qapmoc]

I think that you are confusing the survival of animals with the survival of human civilization Tommy666, life on the Earth will always manage to find a way to keep going somewhere. After all, the earth has been frozen almost from pole to pole, the sea levels have been higher and lower than now, there have been episodes of extreme global warming etc.. but life is still here.

Human civilization on the other hand is so specialized and delicately balanced in its use of energy - food production - etc...etc... that it would stand no chance at all to survive. a few humans would probably keep going in a caveman style of life.

[wildwood]

Another thought. The 'dark' side of the Earth would doubtless become colder than the lowest temp we've know at the poles, expiring all but the hardiest form of life. Unless we are prepared to take the animals, plants and ourselves on a continues journey around the world every year, all will get a very cold botty.

[fluffybet]

another twist. the space shuttle needs to slow down to come out of orbit. So when its in orbit is it simply falling at the same rate its going round the earth