If the Earth Stood Still | Hacker News Reader

If the Earth Stood Still

esri.com

76 pointsbjonathan14 comments

They modeled gravity but not the atmosphere. So the most drastic effect isn't even mentioned - the much longer day length would roast the planet on one side and freeze it on the other.

Also, no mention of what the weather would be like without Coriolis "force" - no cyclones, no prevailing westerlies, no geostrophic winds. Would you get one big Bénard cell or multiples? (Currently there are six).

I suspect that these changes would be much more dramatic than the ones they discuss. Surely some hard SF writer has thought through this further?

I don't think weather is what they were interested in.

Notice they said it was done to demonstrate GIS technology, and GIS stands for Geographic Information Systems

You might have confused "geographic" with "geologic". The use of GIS for meteorology is probably just a little younger than GIS itself.

Weather is most certainly one of the primary domains of interest of GIS.

The other major issue with his analysis is the earth's crust would deform from its current shape into a nearly perfect sphere. The earth is well above the defined limit where a planets shape simply a sphere deformed based on their rotational velocity. So the mega continent he suggests would never form.

I thought about that also, but I think it would take much longer for the crust to change to a spherical shape; much the way that large parts of the northern hemisphere are still rebounding from the loss of ice cover at the end of the last ice age.

Also providing a dampening effect on this transformation, are the weight of both oceans, which are now bearing down at both poles. Water is quite dense, being about 1/3 the density of the earth's top crust. Also, interestingly, it seems like the density and pressure of the atmosphere would be significantly greater at sealevel, especially at the southern hemisphere sealevel, though obviously not much of a factor in crustal transformation.

The earths crust deforms ~1cm each day due to tidal forces. So while it might take a long time to move the last inch or so, the first few miles would change within hours. In fact with an instantaneous stop it would go past a perfect sphere and probably osculate.

I think they're overlooking the effect on the atmosphere. If the water will all flow to the poles, so will the air. If the difference in distance to the center of the earth is 21km then there would be little air left at the equator -- it would be like standing on Everest, or thereabout. Plant and animal life would not survive across broad regions of what is currently inhabitable land.

Further, the water at the poles would be extemely deep, and subject to cold (winter) temps year.

Earth has locked rotation with the sun rather than stopped altogether, but this is related and a fun read: http://en.wikipedia.org/wiki/Hothouse_(novel)

i think the title is misleading - they mean if the earth stopped --rotating-- around its axis

If the Earth stopped altogether it should fall into the Sun. No maps to draw, then :)

Not if it also stopped falling.

Stopped altogether from which frame of reference? ;)

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