arscott said:
If the earth stops spinning, most of the earth's surface will become uninhabitable--it will either be always day (and thus too hot to survive) or always night (and thus too cold). I imagine the edges, where it will always be dawn/dusk will still be hypothetically inhabitable, but other side effects will still apply, such as:
Not exactly. The earth will still revolve around the sun, so you'll actually see a six month light period, followed by a six month dark period.
Each "day" will be a solar year long. It won't be quite as bad as Mercury (which manages to rotate so that one side
is always facing the sun) but it will be pretty danged inhospitable.
-Really weird weather at the border regions caused by the permanent day/night zones and the cessation of the Coriolis Effect (IE: when the earth stops spinning, so do the hurricanes).
-Changes to, or elimination of, the earth's magnetic field (which owes much of it's existence to the earth's rotation). The magnetosphere protects the planet from certain types of cosmic radiation.
-Massive Crop Die-off (From weather/radiation effects described above, as well as the lack of day/night cycle. Most plants need a certain amount of light or a certain amount of darkness each day. Eternal twilight won't cut it.)
Agreed.
As far as an Asteroid hitting the earth, the idea that we'd somehow regress back to a previous period in history is over-simplifying things. Whatever the result, it is unlikely to resemble a particular era of history.
Consider--The asteroid's biggest effect is that it will kill many crops by blocking out the sunlight and otherwise screwing around with the weather. The society of the middle ages was basically an agricultural society where wealth is derived from your control of (farm)land. But traditional agriculture just stopped working.
The 'winners' of such a scenario would be the ones who manage to ensure their food supply. But the two basic methods would be force (beating people up and stealing their food) and science (making corn that grows with less sun). This is very different from the stone age, where resources were plentiful enough and humans were scarce enough that they rarely came into competition, and where getting food was a lot more about hunting/gathering it than engineering it.
Don't forget artificial growth environments.
Also, depending upon the immediate effects of the impact, you may have a) a large human death toll, b) accusations of aggression resulting in wars of various scales, c) massive natural disasters such as volcanoes, earthquakes, tsunamis and massive storms, d) continent-spanning wild fires, or some combination of the above.
Humanity won't actually regress, we'll just find ourselves crippled in some serious ways. Most of the knowledge of science, engineering, and technology will still be around, inside people's minds if no where else, but the resource base used to take advantage of this knowledge will be radically different than it is today. So what's most likely is a hybrid technology level, combining the most sustainable bits of humanity's many technology levels.
Societally, we'll almost certainly drop back to some sort of tribal or feudal state, but that's because most people
can't think of themselves as being part of a group larger than about 1,000 people. It's just too large for most people to internalize. Plus, people respond instinctively to a single leader during crisis.
