It's the End of the World as We Know It...

A question I've been asking round the traps of late:

what would happen if you were able to slow the turning of the earth, increasing the length of time it takes to turn by 10% each day, til eventually it was tidelocked with the sun? How long would it take, and what would be the effects on climate, water, world temperatures, plate tectonics, the Coriolis Effect, the moon, the earth's orbit around the sun, and on life?

how many days before it becomes tidelocked (my initial calc had it at <60 days, using compound interest formula I got <62 days).

how many total hours would it take to become tidelocked, from that first hour of that first 26.4 hour day, to the end of the almost year long last day? going on one year = 365.25 days x 24hrs = 8766hrs for the earth to turn and remain tidelocked with the sun.

and some answers:

TonyC:

It will take 62 "days". But since the length of the day gets longer every day, it will take roughly 10 years. Or to be exact, 88157,46812282817 hours.

I can tell you what will happen on the first and second day. Massive storms as the weather adjusts.

I can tell you what definitely will happen on the last day. All life will have died. All atmosphere on the night side is frozen. All atmosphere on the day side will have evaporated. There is no liquid anywhere unless we're talking about maybe puddles of molten lead from some leftover industrial stock. For that matter, since the atmosphere has either frozen off or boiled off, no air either. Temperature on the day side will be at least 123° C but probably higher. I'm basing this on the daytime temperature on the moon. However, the moon does experience a day night cycle, if a bit odd. Since the earth would no longer experience one, it should be higher than 123 °C but I have no idea how high. Temperature on the night side should be far below freezing and will eventually settle at something higher than -233 °C. It should be higher because Earth still have geological activity and active volcanoes, but how much higher I have no idea. Actually, I take that back. Eventually it will end up like that, but it might be possible that water boiling off will create a cloud cover that will temporarily reflect most of the sun and create some atmospheric convection currents moving heat from the day side to the night side. This can not last but I have no idea how long it will last.

I really can't tell what happens inbetween though.

I don't think it will affect the earth's orbit unless whatever caused it also affects the earth's orbit.

That's about all I can tell you. I can't guarantee the correctness either.

Spikey:

Google is your friend.

"The first thing that I should make clear is that a tidally locked planet still rotates once per orbit. If it didn’t, then the same side would not always face the star! I don’t know if that rules out a tidally-locked earth for your episode, but I will assume that it doesn’t.

"If Earth were tidally locked, there would be no seasons. The only change in the amount of sunlight would come from the slight variation in distance from the sun due to Earth’s orbit being slightly out of round. Instead of seasons I suspect there would be zones of different climates depending how far away you are from the center of the side that always faces the sun. Right on the equator of the sun-facing side, I would expect very high temperatures. In the center of land masses you would probably have scorching hot deserts, and near the coasts there would be huge thunderstorms due to the rapid evaporation of the water. As you go farther away from the sub-solar point, the sun would get lower in the sky and you would have gradually cooler climates in rings. I think that the intense heating on the sunlit side and the cooler climates surrounding that area would set up circulation in the atmosphere similar to the Hadley cells that transport heat away from our equator (http://en.wikipedia.org/wiki/Hadley_cell) but the winds caused by this would not be affected by the coriolis force since the planet is rotating so slowly. So in general you would expect surface winds to blow cooler air toward the sub-solar point, where it would be heated, rise and then circulate back toward cooler climates.

"The far side of the planet would be frigid, since it would never see the sun. Its only source of warmth would be ocean circulation and winds from the warm half of the planet. Even on the sunlit side, much of the planet would never see the sun rise very high, and would be quite cold.

"The slow rotation of the Earth would have an effect on the moon too. Due to the moon’s gravity, the Earth bulges a little bit toward the moon. Right now, the earth rotated much faster than the moon orbits, so the tidal bulge is always a little bit ahead of where the moon’s gravity “wants” it to be. This means that the moon’s gravity is actually slowing the earth’s rotation down and the moon is gradually moving away from the earth. If the earth were rotating really slowly, then the exact opposite would happen (I’m assuming that the moon starts off in its current orbit). The moon would gradually try to make the Earth spin faster, and in doing so the moon would lose energy and come closer to the Earth.

"I would imagine that the lack of days, and the sun being at the same place in the sky all the time would have some interesting effects on life too, but I know very little about biology so I’ll leave that for someone more qualified."



UPDATE:


And then Chris pointed me to this:

which includes these maps, showing what happens when you move the centrifugal bulge of the equatorial oceans (the red bits are where the air's too thin to breathe):



and towards the end...



what the program doesn't address is if the earth becomes tidelocked with the sun; instead it slows the turning of the earth down to 6 months of day and 6 months of night. But still plenty of goodness to be had.

Combining that last map then with my first one, where the earth does get stuck one side always sunward, you get:

Option #1 Australiasian Burnation:




Option #2 Eurafrican Fry-Up:



Option #3 Flamerican Inferno:




SO.....my question is this: out of those 3 options, if this was the background for a post-apoc game which would offer the most potential for awesome survival adventure?

... and what if you added vampires?