[1] What are the Likely Senarios to make the sun rise from west?

What I mean is that, the sun currently rises from the east, what does it take to make the sun rise from the west.

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afbS

It would require the Earth to spin in the other direction. Which is mind-bogglingly improbable.

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Quaeso quousque humi defixa tua mens erit? Nonne aspicis, quae in templa veneris?

Are you afraid you're going to die via opposite rotational motion username?

Have no fear. The Earth won't be going in the wrong direction. However, I don't know your directional skills. If they're as bad as mine you've gone in the wrong direction many times!

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"The bread's hollowed out --- the veggies go on forever --- and --- oh my God! --- it's full of meat!" - Maksutov

With a triple inversion layer once here in oregon, we saw the sun rising in the east, and a miarge of it rising in the west!

freakiest thing I ever saw.

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There is no problem that cannot be solved by a suitable application of high explosives - US Army Demolitions School

I just saw Hayley's comet, she waved, Said "why you always running in place? Even the man in the moon disappeared, Somewhere in the stratosphere" - Shinedown

http://worldsofothersuns.home.comcast.net/

Back to an earlier earth rotation thread....

Start again with wrapping a copper coil around the earth several hundred times. But this time instead of just discharging the electic current, we also make the oceans into a giant battery, and charge the oceans. Then once the rotational energy of the earth has been converted into current and dumped into the oceans (sorry sharks) we reverse the polarity if the thing and discharge the planetary ocean batteries into the coil. Voila, the earth starts to rotate backwards.

If we start now, we can be done in 500-600 years.

nothing. there are no likely scenarios for that to happen. however, in the unlikely scenario that is is to happen, there will be no one and nothing left alive to witness it.

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Who are you going to believe, me or your own eyes? -- Groucho Marx

Get in a high-speed jet and fly west very quickly just after sunset. If you can go faster than the Earth rotates, then the Sun will rise. This is easier at higher latitudes.

Also, if you watch a sunset in a very flat place (like on a western beach), squat down. Just as the Sun vanishes from view, leap up quickly. Your added height might be enough to allow you to see the Sun appear again for a moment, then set for a second time. I did this in Florida some years back, and it worked. Amazing.

It's true. The only way I can see the Earth starting to spin in the other direction is a truly massive impact by a planetary body. And at that point, nothing is left. Depending on the size of the impact, we might even break apart.

Edit:

The BA posted before I could. And I have to say that his ideas are much more clever than my brute force method. #-o

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Quaeso quousque humi defixa tua mens erit? Nonne aspicis, quae in templa veneris?

We could simply rename east as west and west as east.

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"Oh no no no I'm a rocket man Rocket man burning out his fuse up here alone." -- Sir Elton John

J Pax

What a beautiful, elegant solution. Nobody has to die, nobody even has to jump. It might be a bit of trouble for cartographers and compas makers, though. We could actually change the labels for north and south as well, and thereby eliminate the slight against Australians and other folks for having to live on the underside of the earth.

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As above, so below

no fair, BA: since they stopped flying Concord it's not possible for simple mortals like ourselves to see that.

Jpax: =D>

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Who are you going to believe, me or your own eyes? -- Groucho Marx

So simple- I love it!
=D> =D>

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If this writing is blue you're going too fast!

Gentlemen and Ladies,

Let’s answer my above question scientifically, in reality what does it take to make earth stop or go visa versa.

If there was a planet many times larger than earth and going between sun and earth but the opposition direction, could it really stop earth for 1 or 2 or 3 or 5 days or even make earth spinning the other way?

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afbS

Look, one thing you need to understand is that planetary bodies are not like cars, where you can put on brakes and then start the engine and stuff like that. They don't "stop" for several days and then start "going" again. They are big masses that are floating in space. They keep going in one direction unless something puts a force on them to change direction. For example, the earth keeps going around the sun because gravity pulls the earth toward the sun. Otherwise the earth would simply keep going in a straight line out somewhere.

So to answer your question, if a big planet passed in between the earth and the sun, there's no guarantee that it would do anything at all. Venus isn't that big, but it does spend all of its time between the sun and the earth, and although I'm sure it has some effect on the earth, it's not a big effect. So, if a big planet passed between the earth and the sun, and passed close enough to the earth, it would certainly disturb the earth's orbit, but it would not "stop" it. Maybe an easy way to imagine this is if I throw a ball into the air and you throw another ball that hits mine. Certainly it will change direction, but neither will "stop." They'll still travel somehow, eventually downward, right?

If the object comes very close to the earth, then something more dramatic would happen. The part of the earth close to it would be pulled more than the part of the earth far away from it, so the earth would be ripped apart.

Now, before you get too concerned about this, remember that the solar system itself is very big, and the planets themselves take up a very, very, very small part of it. In addition, if a big planet were really coming our way, we would see it coming. It:s possible to miss a small asteroid, because the don't stand out that much, but consider Venus, for example, which is smaller than the earth and is quite far away. It is still the third brightest object in the sky, I think. So if a planet were five times as big as the earth, it would be quite bright before it got all that close. It would also influence the orbits of other planets, so we would know it was coming.

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As above, so below

Huh... username24 seems to have quite the fixation on halted and reversed orbits or rotations.

Couldn't all (well, most) of these questions have been asked in a single thread?

This has already been discussed in This thread. I'm not sure what his motives are, but he doesn't seem to be answering any of the replys.

with regards

username24: you really should consider the sizes and masses involved. i'm no expert on this subject (but there are many here who are), but like Jens already pointed out: there is no way for a body as massive as a planet to simply stop spinning and then restart. it's not a golf ball. the forces involved and the different densities out of which -for instance- Earth is built up would result in massive forces that would simply rip the planet apart.
let's assume for one moment that some force working on the outside of the planet would slow down the rotation. my guess is that those parts of the earth that are heavier (or of a different composition) than the crust would take longer to slow down and the resulting friction would cause the crust to rupture and tear apart. since life as we know it all takes place on or inside the outer layer of Earth, this would result in all life being crushed.

of course, it would be all downhill from there.

i can't imagine any force being able to stop rotation of a planet in any humanly conceivable time span with the structural integrity of that planet remaining intact. so has Mars stopped rotating? not likely. pieces of it would be all over the place.

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Who are you going to believe, me or your own eyes? -- Groucho Marx

How about this,

what does it take to topple the earth while spining and rottating in the current direction?

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afbS

Alot of energy

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If this writing is blue you're going too fast!

how would earth 'topple'? it is not an egg spinning on a plate. it is a ball floating in space, where there is no up or down. where would it topple to?
there is a continuous strong force exerted on earth by the sun, yet earth doesn't 'topple' towards it. the amount of energy required to create a force to turn earth upside down is inconceivably large, IMO.

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Who are you going to believe, me or your own eyes? -- Groucho Marx

It would take a rotational torque to accelerate it from the current orientation then an an equal and opposite torque to stop it at the new one. Since the Earth would still be spinning about its axis during these two (improbable if not impossible) events there would also be some extreme giroscopic effects that I wouldn't even want to contemplate. It ain't gonna happen You could demonstate the effect though. Sit in a gimbled chair that allows free rotation in three axes and also rotates about a central point on a long arm (representing the Earth's Orbit about the Sun. Sit in the said chair and holds a spinning heavy globe to represent the Earth as it rotates at present. Attempt to re-orientate your globe and have someone observe what happens. You may also want to take a sickybag with you while you conduct this experiment. Actually I'm sure there are folk on this board that can tell you exactly what would happen but I'm kind of rusty on giros and how they behave as regards all the 'hand/thumb rules')

As has been discussed elsewhere the Earth does undergo periodic magnetic pole reversals which is readily deduced from geologic records, none of which have major implications for life on earth (although possibly homing pidgeons might get a little confused if one were to happen overnight - they don't though, they happen over a few +- thousand years)

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By asking questions we sometimes get the wrong answers, from wrong answers we learn to ask the right questions.

username24: The general answer to all your questions about significantly changing the rotation of the earth is - the earth would have to be struck in the right way by something so massive and moving so fast that no life would survive, nor would the world even look the same. There's nothing out like that in the neighborhood, so it is a nonissue.

So would you mind answering why you keep asking questions like this?

If such a planet did pass near the Earth, it could well affect our orbit or even throw Earth out of the solar system altogether. However, Earth would maintain its angular momentum and continue spinning almost exactly the same as now. To alter the spin you have to somehow connect Earth and Planet X with some force that can carry angular momentum from one to the other. Perhaps a giant axle, set of gear wheels, or toothed-belt drive. Nothing else will do! As a matter of fact, the Earth's spin is (very very very very very very slowly) slowing down now because of the tidal influence of the Moon - angular momentum is being transferred to the Moon and making it move away in its orbit. But unless Planet X comes about as close as the Moon, it will have a totally negligible effect on our rotation.

In short, NOTHING CAN CONCEIVABLY STOP OR REVERSE THE ROTATION OF THE EARTH!!!!!

Very cool.

I just crunched some numbers. The Sun's disk is a half arc-degree. The usual formula for distance-to-horizon on a spherical earth is about D = sqrt(2hR). The angle of line-of-sight is about A = 2h/D * 180/pi, in degrees. If you start with your eyes on the sand (h=0), your A is zero. To change it by a half degree, you have to raise your eyes to a height h such that 2h/sqrt(2hR) * 180/pi = 1/2, or to a height h of about a quarter mile.

But we can start from a different point of view. In order to get a half arc-degree change from jumping up 2 meters, the horizon has to be closer than (2*2*180/pi), or 230 meters. So, just duck down so that the horizon is no more than 230 meters away, maybe the top of a small dune or the top of the waves, until the sun drops below it, then jump up.

I'm not sure it would work if it were very flat, but I'm going to try it out.

PS: frogesque's post reminded me that there could be refraction effects involved too

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http://cleardarksky.com/c/DrhmNCcs0.gif

I've played 'chase the sunset'. All you need is a small rise such that you can view a distant horizon without interferance. When the sun sets at the bottom of the rise you run up the slope a bit 'till you see it again. Repeat untill you run out of slope. Fun game with the kids, helps if you have a really blood red sunset as they shouldn't damage their eyes.

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By asking questions we sometimes get the wrong answers, from wrong answers we learn to ask the right questions.

That's a really cute idea. I'll keep it in mind to try it with my kids (when I have kids).

Is this true? I would love to see it if it can actually happen!

You may want to have a look at this thread from a while back. I did some calculations on the energy required to stop the Earth's rotation.

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"A mystic is a person who is puzzled before the obvious but who understands the nonexistent." -- Elbert Hubbard

Spin your tectonic plate around?

I'm not crazy about the pattern that I see here in this thread, and I worry that I'm propogating something I shouldn't :-? ; but it sparked my curiosity about the kinetic energy in a spinning planet.

If anyone has too much time on your hands :wink: , I would be curious to know how to visualize such a force as the kinetic energy stored up in a spinning planet. Such as x^y Horsepower. I know it must be huge. How does this relate to the centrifugal/centripital (can't think of the right word at the moment). In other words, how much force keeps the poles pointing the direction that they are pointing?

No force keeps them there. They stay there until some force acts upon them and moves them. Better have a relook at Newton's Laws