Where would the dividing line be if the Earth stopped rotating but continued to orbit the sun?

Question

I'm doing some research for a book, and I'm wondering what countries and areas would be in daylight perpetually, and inversely stuck in night, as in if there's a certain line on the axis and through which areas. Also, I know the effects of such an occurrence from another answer on here, but do you think it's possible for people to still survive, as in could they physically survive, and could they still eat and drink in any way possible...and if so, what would happen when the two sides flip after a period (a year I'm told), and would this flip be drastic or slow? Thanks ahead of time people.

Answer 1

I don't think anyone could tell you for certain what would happen if the Earth did not rotate as it currently does. I can, however, mention some things which you may want to look into if you are seriously researching this topic.

When you say the Earth stops rotating, I assume that you mean that one side of the Earth is always facing the Sun. This is what is known as being tidally locked, like the Moon is to Earth and Mercury is to the Sun. Venus is not tidally locked, but its rotation is very slow. Keep in mind though that the Earth would still be rotating, once per revolution about the sun (once per year). The Moon rotates once a month, Mercury once a mercurian year, and Venus, with a very slight retrograde rotation, actually completes one rotation in a little more than one Venusian year.

One of the most profound effects would be that one side of the Earth would be much warmer than the other. For comparison, take a look at the differences in day side and night side temperatures of Mercury and the Moon. Venus is an odd exception, its dense atmosphere is mostly CO2 which traps the heat and causes daytime temperatures hotter than Mercury's day side temps. However, the atmosphere also convects the thermal energy very well into the night side so the temperature difference is not as pronounced as on other slowly rotating bodies.

While the Coriolis effect does affect the movement of all fluids on the planet, solar heating is a much more influential factor on the movement of the atmosphere and the oceans. It is the solar heating which drives the convective processes on Venus. A study of the motion of clouds on Venus may give you some insight into how the Earth's weather patterns might be affected. The Coriolis effect is much more pronounced on a planet like Jupiter which has a much faster rotation and much less solar heating.

Another factor which may be relevant is the strength of the Earth's magnetic field. It is not well known exactly how much the rotation of the Earth affects the motion of the molten rock in the mantle which gives rise to the magnetic field. My guess is that it would be significantly reduced since the only remaining perturbing force of significance would be the tidal forces caused by the Moon.

If we were to assume that none of the above affects were sufficient enough to render the Earth completely uninhabitable by life as we know it, and if we were lucky enough to have the Pacific ocean directly beneath the Sun, then I would venture to guess that a habitable zone would be possible within say twenty degrees from the terminator. The reason we would want the Pacific Ocean to be the spot directly under the Sun is because fluids (water in this case) transport thermal energy much better than solids. Besides preventing excessive heat build up in one location, it might also enable the rest of the planet to be heated by convective processes while at the same time establishing the habitable zones around the terminator.

HTH

Charles

Answer 2

Well first of all, what you are talking about is not an actual stoppage of the Earth from rotating... it would be synchronous rotation - one revolution per year. That's what the moon does - one revolution per Earth orbit.

As to what side would be facing the Sun, that could be any side at all. The Earth is round, so there's no side that would be guaranteed the sunny spot if the Earth suddenly switched to synchronous rotation.

By the way, you should know something: the amount of energy that would have to be transfered to the Earth to cause such a drastic change in our planet's spin would be astronomical. Suffice it to say the only way it could happen that I know of would be for a dwarf planet to hit the Earth with enough force to pretty much destroy every living thing on the face of the globe. There would be no surviving at all for anything more than a microbe, let alone any people who can eat or drink.

Answer 3

If the earth just stopped rotating, the parts in sun and the parts in shade would change during the year as we still orbited the sun. Any one spot on earth would spend roughly 6 months in sun (a very long morning, a very long mid-day, and a very long evening twilight), and then 6 months in darkness.
There would be no dividing line.

If we somehow changed to a rate of rotation that kept the same face of the earth towards the sun at all times (much like the moon as it orbits the earth does now), then yes -- one side would always be in sun, the other always in darkness. But *what* part would be in the sun? That depends on what side was facing the sun when our synchronous rotation rate was established. The earth is a spheroid (almost a circle, but squashed a bit from top to bottom and bulging at the equator) -- there is no "start" or "end" around the earth.

Answer 4

If the Earth stopped rotating (assuming that it does so in a way that does not kill us all), then a point on the equator would always point to the same star. (I'm stopping sidereal rotation, which is the closest to "true" rotation).

Let us say that you are at the point where, on January 1, the Sun is directly overhead.

Because the Earth is in orbit around the Sun, then the Sun would continue to appear to travel on the ecliptic, taking a whole year to come back to the same position on the celestial sphere (i.e., in line with the same star)

So, three months later (around April 1) the sun would be setting for you (I assume you have not moved from your January position) in the direction we presently call East. Another 3 months (we are now a little after July 1), it is "mid-night" for you.
Come October and the sun is rising in the West. Finally to January and your local "noon"

The preferred location on Earth (if you enjoy sunlight) would be the point where local "noon" corresponds to aphelion (the point of Earth's orbit furthest from the Sun). During that period, the apparent movement of the Sun in the sky would be the slowest, therefore to the maximum period of time from sunrise to sunset.

The"poles" would not be defined by Earth's rotation axis. They would be two points (one north, one south) at 90 degrees from the projection of the ecliptic on earth's surface. From a pole, the Sun would simply circle the horizon (in a one year period), never rising, never setting.

Answer 5

Charles N answers most of the question (though he is wrong about Mercury--it rotates 3 times every 2 mercurian years). And, of course, there would be no coriolis effect because that effect is caused by the rotation of the earth.

Answer 6

it is occurring very slowly each and each and every of the time. First the gravitational field on the Moon might want to weaken to the point the position its orbit might want to decay; the Moon might want to collide with the Earth. If it were not recreation over with information from that element, than we may have weathered countless lengthy days and various lengthy nights. If we blasted the Moon away, ultimately days might want to develop into too lengthy and too warm; nights, too lengthy and too chilly. we may attempt to vacation a convenience zone between day and evening at the same time as attempting to strengthen issues and save issues alive (to devour). finally, nature might want to win if we did not have our act mutually with information from then. The Earth's orbit might want to gradually decay and that could want to reason too a lot geological havoc. the end. yet do not problem, it received't take position for a lengthy time period.

Answer 7

so angular deceleration w’ = w/t, where w=360°/(24*3600) 1°/s is angular speed of spinning Earth nowadays, given t=1year or t=365.25 days or t=365.25*24*3600s; thence w’ = {360°/(24*3600)} / {365.25*24*3600} =~ 1°/s^2; the linear deceleration for those living in equatorial zone is a=w’*R, where R=6400km is Earth’s radius, thence a=(1/180)*pi*6400*1000 = 111000 m/s^2; so angular deceleration of 1°/s^2 will produce an effect on an average person of 60kg F= 60*111000 =666*10^4 N = 666 tons of sideways force; awesome, God bless us!