Thursday, February 28, 2013

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:


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.


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 ( 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."


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: 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?


  1. Possibly relevant to yr interests, an Aftermath documentary from 2010 on this very subject. Although, IIRC, their slow-to-a-halt timescale was 5 years or so.

  2. I think i'd find the first firearm I could and shoot myself.

  3. Give me Option #3 Flamerican Inferno because if America is uninhabitable our post-apocalyptic survivors might not me Americans, which would be interesting because almost every post-apocalyptic flick always features bootstrapping New World types. Even Italian flicks are set in nuked US of A. It's strange phenomena.

  4. @ Jonas: I think it's cause Amerika! is this weird cultural invasion not only of media but of dreamspace as well... like it's reeeeaaallly hard for to imagine a post Apoc not set there... ok I could go for a UK apocalypse as well, but it's definitely not the default setting in my brain either. The extra weird thing is whenever I got to the States I have this wack feeling that I'm inside my television.

  5. Here is another weird option for you to investigate. What would the setting be like if, instead of the world halting its rotation, the moon was locked in its orbit, such that part of the world was in a continual state of solar eclipse?

  6. One thing that was glossed over in the Nat Geo video was that without a magnetic field to deflect harmful radiation from the sun would basically cook the planet. There wouldn't be anything living without the magnetic field shielding us. And I think with a 5 year heads-up, people would be making their way into deep cave systems that would shield them from the extreme temperatures, but the question of acquiring food would be another matter altogether.

  7. @ Brandon: Hmmm. I like the concept, but I can't see how it would work: if the moon was locked in a position that placed it permanently between the sun and earth, yep you've got your eternal eclipse. But if the world's still turning, then the land within the shadow is constantly changing. From a huzzah! permanent night! point of view, you'd have to be always on the move, at 1,600km an hour. Your typical passenger jet clocks in at around 900-1000km an hour. You'd be stuck on a plane the whole time.

    Or on a satellite in the La Grange between the earth and moon.

    If you mean the moon is locked over a single patch of earth in geosynchronous orbit, then you lose the eclipse effect as the moon is no longer fixed between the earth and sun.

    Maybe if the earth was tidelocked with the sun AND the moon permanently stuck between it at the sun, that'd get you your eternal eclipse.

    But it's seems hard enough just getting the world to stop turning, let alone seizing the moon.

    If the world did stop turning though, then the moon's orbit would slowly collapse, bringing it closer and closer. Which would probably cause a lot more eclipses, with bigger shadows.

    Until it all goes Thundarr and the moon falls apart.

  8. @ Greg: Yeah they sorta went "oooh Solar Radiation Bad" but didn't show anyone falling apart at the seams.

    I'd like to know more about it, why it's bad, and if life can survive in a lack of magnetosphere. Actually, waterbears can.

    How deep would you have to go to be able to mitigate the effects of the radiation? and could you get away with hazmat suits or something for topside exploration?

    1. Given that the show is "family-oriented" for viewing, I think having people melt on-screen would be prohibitive.

      Another thing that was over-looked is the eventual break-down of society and the violence that usually occurs when there is no longer any central authority as the eastern seaboard of the U.S. would be flooded (actually that would be a good thing considering the dysfunction of our gov't).

      As for how far to into the earth one would have to go to stave off the effects of radiation, I guess that would depend on the amount of metals in the rock (i.e. lead). As for hazmat suits, I think another problem would be if you could supply enough compressed oxygen in tanks in order to breathe in the suits while exploring. They made it pretty clear that the air would be so thin at the equatorial regions that it would be like trying to breathe at a height higher than Mt. Everest.

      Either way, it's a pretty hellish place to try and live.

  9. @ Greg: yes it would be a thoroughly shit place. Still, I don't doubt that some few would try to find a way.

    Will see if I can digup info about the penetration of solar radiation.

    Also, now I need to go a-hunting for stuff about bunkers and wotnot and what governments have deep underground facilities.

    This will be fun.