View Full Version : If the World Stopped Spinning?


pharaohmoan
01-14-08, 11:40 AM
What would happen if the world stopped spinning? also
What if the Earth rotated twice as fast?

Key things i need to know are what effect would gravity have on us in the two scenarios above.

cat2only
01-14-08, 11:52 AM
Instantly or over time?

cosmictraveler
01-14-08, 12:05 PM
If it stopped one side would be super heated and everything would cook to death on the other side of Earth it would freeze and those there would freeze to death. Yes it would get that hot and cold if the Earth stopped which one day it will. It is slowing down about one second a year or so. As for speeding up that won't happen so that's not to worry about. Gravity remains the same in both scenarios.

Myles
01-14-08, 12:14 PM
What would happen if the world stopped spinning? also
What if the Earth rotated twice as fast?

Key things i need to know are what effect would gravity have on us in the two scenarios above.

Have you ever observed the moon through a telescope over a period of time ?

sly1
01-14-08, 12:17 PM
If it stopped one side would be super heated and everything would cook to death on the other side of Earth it would freeze and those there would freeze to death. Yes it would get that hot and cold if the Earth stopped which one day it will. It is slowing down about one second a year or so. As for speeding up that won't happen so that's not to worry about. Gravity remains the same in both scenarios.

Since the earth is not roating.....It would still be orbiting the sun....SO for only 1 side of the earth to see the sun would mean it had a synchronous orbit like the moon and would imply a roation. If the earth did not rotate at all and was still orbiting the sun, there would still be a day night cycle right? Of course at a much slower period of time.

so the non spinning earth's day would be 365 spinning earth days?

pharaohmoan
01-14-08, 01:42 PM
if it stopped would we float or would be pinned down if the awnser is either please say y

Nickelodeon
01-14-08, 01:51 PM
What would happen if the world stopped spinning?
I'd get off.

shichimenshyo
01-14-08, 02:08 PM
I'd get off.

I dont see why you have to make everything sexual :mad:

orcot
01-14-08, 02:15 PM
if the earth would spin 2times as fast, the the planet would still rotate like it did 2 or 3 billion years ago, live has evolved on earth when it proberly spun even fasther. The biggest difference would be the obvious shorter day and a smaller temprature difference.

[a-5]
01-14-08, 03:32 PM
I dont see why you have to make everything sexual :mad:

LMFAO.

DwayneD.L.Rabon
01-14-08, 03:33 PM
Well, there could be two sunrises and sunsets in a day, if you lived on the horizon, or treminator of day and night. (such a scenerio has been mentioned in south american legends as i have heard).
Also one side of the earth would exsperince a ice age, and one side a heat wave, or very tropical enviorment, as the water of the oceans would evaporate causing a humid mist to cover the side facing the sun, filght would be easier you probally could get a hang glider and float half way around the world on thermals. much simualr to some speculation about the life of people in south americas past, hang gliding from tall mountains, and people living in on tall mountains. mainly because the mist lower is so dense that you could not see through it, but you could walk down through the mist almost to the bottom of the oceans, like the atlantic, Islands that are now in the ocean such as japan and england would become large mountains and be connected to the main lands. (which may be the reason for some of the sturctures found of the coast of the islands of japan). Flying in a hydrogen ballon would be easy but it would be just as easy to fly using a oxygen ballon. another reason for living on top of high mountains the ablity to breath.
The earth does not spin very fast only about 1046 miles per hour, and yes it is noted as slowing down, but there are other effects that may cause the earth to stop, the earth tilts 1 to 1.4 degrees every 100 years of about 0.5 miles per year at this rate the north pole or south pole was facing the sun some time in the past 5,000 to 10,000 years ago. the sphinks and pyamids of eygpt are thought to have been built 3,000 to 5,000 years ago some say 10,000 years ago, for the earth to do a 180 degree turn it would take from 18,000 years to 12,857 years.
If we chose a date 5,000 years ago about the time of the sphinks and pryamids then the earth has turned 50 degrees to to 70 degrees, if you and the current axis tilt to that say 23.5 degrees, it for the most part defines that the entrance into the pyramids was faceing the sun when they where built, which makes a lot of sense.

If the earth stopped spinning it would start again, as the force that causes the earth to spin is the sun, so if you look at how the Planet Neptune spins, you would find the way the earth would start spinning again, the spin axis would be at what we call the equator.
The current equator acts in opposstion to the force that caused the orginal spina of the earth, and so the earth should stop spinning soon, haveing about 23.5 degrees left before it stops which comes out to about 2,350 years from now. even so the current postion of the earths rotation actually defines that the earth does not rotate on its oringal axis but on the second axis which is bascially just a wobble, kind of like a lot of skips around in a circle, some skips are 30 minutes long some 90 minutes ect..... one thing about being in this postion is that we could lose skips rather quickly in the wrong motion causing the earth to come to a stop much quicker, a very good reason for not allowing nuclear testing.
The ozone whole has marked features of this type of effect on earth, as well Elnino, however elnino remains difficult to sort out as the region was subject to nuclear testing.


Many of the facts of geology support that the earth had a different oreintaion and rotation, even the dipcitions drawn and made by eygptian and ancient astronomers, as well biological life cycles also give some matches for a different rotation period, ancient calendars ect.... give reference ect...

One thying seems clear humans survied or came in to existance in that condition.


DwayneD.L.Rabon

Carcano
01-14-08, 04:11 PM
If the earth stopped spinning it would start again, as the force that causes the earth to spin is the sun...
Hmmm, how does that work?

It makes sense to me that the earths rotation would be slowing down because of friction with the atmosphere.

cosmictraveler
01-14-08, 04:12 PM
if it stopped would we float or would be pinned down if the awnser is either please say y

Gravity is caused by the mass not by the spin of an object.

Enmos
01-14-08, 05:18 PM
Well, there could be two sunrises and sunsets in a day

:wallbang:

day
ľnoun
1. the interval of light between two successive nights; the time between sunrise and sunset: Since there was no artificial illumination, all activities had to be carried on during the day.
http://dictionary.reference.com/browse/day

James R
01-14-08, 09:26 PM
What would happen if the world stopped spinning? also
What if the Earth rotated twice as fast?

Key things i need to know are what effect would gravity have on us in the two scenarios above.

There wouldn't be much difference in gravity in either case.

If the Earth stopped spinning, then apparent gravity everywhere would be the same as it is right now at the north or south poles, which aren't affected by the spin anyway.

If the Earth spun twice as fast as it does now, people would be a little lighter on the equator (I think the fractional decrease in apparent weight would be about 0.6%)

As cosmictraveler pointed out, apparent weight on Earth is mostly due to the mass of the Earth, and not primarily due to its spin. Gravity is due to the attraction of all bits of matter in the universe for all other bits of matter.

D H
01-14-08, 10:55 PM
Centripetal acceleration due to Earth rotation acts to slightly counter the acceleration due to Earth gravity. The centripetal acceleration varies with latitude. At the equator, the value is 6378\text{km}*(2\pi/86400\text{sec})^2 or 0.0337 m/s2. This is quite small compared to 9.8 m/s2.

A much more significant effect is that the Earth's rotation affects the shape of the geopotential surface. The Earth's oceans would split into two polar oceans separated by a dry equatorial landmass if the Earth somehow stopped spinning but maintained its spheroidal shape. This article (http://www.esri.com/news/arcuser/0703/geoid2of3.html) discusses this "what if" scenario.

A thumbnail view of the non-spinning Earth:
http://www.esri.com/news/arcuser/0703/graphics/geoid7.jpg

For a larger view, see
http://www.esri.com/news/arcuser/0703/graphics/geoid7_lg.jpg

pharaohmoan
01-15-08, 05:37 AM
Centripetal acceleration due to Earth rotation acts to slightly counter the acceleration due to Earth gravity. The centripetal acceleration varies with latitude. At the equator, the value is 6378\text{km}*(2\pi/86400\text{sec})^2 or 0.0337 m/s2. This is quite small compared to 9.8 m/s2.

So does this mean if the earth stopped spinning and there were no centripetal force would we still be able to walk on earth, and would buildings still stand? Is a body that stands on the north pole heavier than on the equator?

pharaohmoan
01-15-08, 05:38 AM
Have you ever observed the moon through a telescope over a period of time ?

No why what happens appart from the different phases that is?

DwayneD.L.Rabon
01-15-08, 08:51 PM
Hmmm, how does that work?

It makes sense to me that the earths rotation would be slowing down because of friction with the atmosphere.

Well Carcano
The sun has a interface with the earth,where the earth is bound to the sun.
The sun rotates and that motion causes a motion in the earth, depending on where the earth is when it stops, will determine the new start velocity.
if at the equator the the new velocity will be determined by the motion of the suns equator, if away from the equator then at that velocity. eventualy the speed picks up and the earth starts spinning being positioned as the planet neptune, with the center of spin facing the sun, when the earth reaches a certain velocity it will start turning upward where the axis of spin departs from its position facing the sun, the axis then moves north or south and over time will again face the north. At about the 45 degree the spin changes from the primary spin to the secondary spin wobble, and there after the wobble spin beings to become more dominate.

It may be that both venus and mercury may once again start rotating, the unknown factor would suggest that it takes some long duration of time before the spin begins again if you trust the inference of the effects of mercury and venus.

91,200,000 miles mark a certain barrier for the sun, the out come of the effect of that barrier remains to be exsplored, earth is just about right at that distance from the sun,just out side of it, once earth passes through that barrier it just may mean no rotation for the earth, permeantly.

The lack of centrifugal force would cause the earth to exspand, which may speed up the revoultion around the sun, making the year shorter.


DwayneD.L.Rabon

D H
01-16-08, 01:49 PM
The sun has a interface with the earth,where the earth is bound to the sun.
The sun rotates and that motion causes a motion in the earth, depending on where the earth is when it stops, will determine the new start velocity.
There is essentially no coupling between the Sun's rotation and the Earth's rotation. There is a very, very, very small coupling between the Earth's orbit about the Sun and the Earth's rotation about its axis.

Gravity is a 1/R2 force. Tidal effects result from the gradient of the gravitational acceleration, so this is a 1/R3 effect. This is why the Moon is the primary driver of tides on the Earth even though the Sun is much more massive than is the Moon. Tidal coupling is an even weaker effect than tidal gravity: 1/R6. (See http://en.wikipedia.org/wiki/Tidal_locking#timescale). The Sun will blow up to a red giant and condense into a cinder long before the Sun has any noticeable effect on the Earth's rotation.

DwayneD.L.Rabon
01-16-08, 08:17 PM
So then in your assement, the orientation of mass on the sun, has no effect on the daily rotation and revolution of the earth.

I would say that the suns distriubtion of mass 14.9 hours ahead of earth has a direct effect on the earth motion both in rotation and revolution. (and may be as small as 1.3 seconds under small variations of the weak force).
Also that it takes about 1 degree of the suns surface to hold the earths mass in orbit. disturbance that occur within that one degree along the line of earths orbit determine the variation in earths motion.

59,750,557 square miles of the suns surface equal 1 Degree

Also the barrier at 91,113,792 miles form the sun is the suns rotational force acting on the solar system, it is this barrier or it should be said, it is the "envelope" as it spans the solar system causeing the revolution of the planets around the sun. Once the earth passes past that point it will move as venus and Mercury. (So the earth is about to fall out of the envelope).

DwayneD.L.Rabon


DwayneD.L.Rabon

Captain Kremmen
01-17-08, 07:19 AM
Well, there could be two sunrises and sunsets in a day, if you lived on the horizon, or terminator of day and night. (such a scenerio has been mentioned in south american legends as i have heard).
Also one side of the earth would experience an ice age, and one side a heat wave, or very tropical environment, as the water of the oceans would evaporate causing a humid mist to cover the side facing the sun, filght would be easier you probably could get a hang glider and float half way around the world on thermals. much simualr to some speculation about the life of people in south americas past, hang gliding from tall mountains, and people living in on tall mountains. mainly because the mist lower is so dense that you could not see through it, but you could walk down through the mist almost to the bottom of the oceans, like the atlantic, Islands that are now in the ocean such as japan and england would become large mountains and be connected to the main lands. DwayneD.L.Rabon

Love this Dwayne. The idea of hang gliders as a form of transport on an earth that has stopped spinning. On the sun side are mountains which were under oceans, now covered in mist.

DwayneD.L.Rabon
01-20-08, 03:32 AM
Well there are different stages to such a event, before the water evaoprates and creates a dew or mist across the face of the earth. there is the exspansion of the earth as a result a lack of centrifugal force, in which the water, oceans will be pushed up, neary covering the surface of the earth to the points where only the mountain tops can be seen (water world). it would rain for a while, as well a boat would be handy to have around.
It will take awhile for the sun to evaporate the water off the surface of the earth to exspose land.

Sounds like a exact dipiction of the story of Noahs Ark recorded in the Bible.

DwayneD.L.Rabon

DwayneD.L.Rabon
01-20-08, 03:35 AM
Well there are different stages to such a event, before the water evaoprates and creates a dew or mist across the face of the earth. there is the exspansion of the earth as a result a lack of centrifugal force, in which the water, oceans will be pushed up, neary covering the surface of the earth to the points where only the mountain tops can be seen (water world). it would rain for a while, as well a boat would be handy to have around.
It will take awhile for the sun to evaporate the water off the surface of the earth to exspose land.

Sounds like a exact dipiction of the story of Noahs Ark recorded in the Bible.

DwayneD.L.Rabon

DwayneD.L.Rabon
01-20-08, 03:35 AM
Well there are different stages to such a event, before the water evaoprates and creates a dew or mist across the face of the earth. there is the exspansion of the earth as a result a lack of centrifugal force, in which the water, oceans will be pushed up, neary covering the surface of the earth to the points where only the mountain tops can be seen (water world). it would rain for a while, as well a boat would be handy to have around.
It will take awhile for the sun to evaporate the water off the surface of the earth to exspose land.

Sounds like a exact dipiction of the story of Noahs Ark recorded in the Bible.

DwayneD.L.Rabon

Captain Kremmen
01-26-08, 03:39 AM
Have you ever had that deja vu feeling?

DwayneD.L.Rabon
01-26-08, 08:55 AM
Sorry about the extra post,must be interferance from the magnetic feild, time delay.:D

Apparently after the flood in the story of noah, some kind of physcial change occured to noah, and or his sons, so it does seem consitant, as humans could exspect a change in the gestation time or duration of pregancy. however there seems to be no mention of a endless day that would suggest the earth stopped spinning completely.

DwayneD.L.Rabon

superstring01
01-26-08, 09:41 AM
Venus "spins" once a year, it's about the same size and nothing "floats" off it and the "sun doesn't make it start spinning again."

~String

Syzygys
01-26-08, 09:57 AM
What would happen if the world stopped spinning?

Compared to what? There are 2 scenarios:

1. It doesn't spin on its axis. Then we would have 365 long days, as Earth advances on its path around the Sun.

2. It doesn't rotate compared to the Sun, meaning it rotates once in every 365 days, around its axis.

You probably meant the later. I doubt there would be serious cataclysms, because the evaporating water would form a mist and protect from more sunshine. Will do a little research on the problem.

DwayneD.L.Rabon
01-26-08, 09:58 AM
Well superstring
Veuns as i suspect is gradually being pushed around, simular to the out sides of the circle being pushed every few days, while the central parts of the circle are attempting to bring about a spin.
the same thing will happen to earth eventually, right know earth has enough force acting on tyhe center that the earth if it where to stop at this distance from the sun it would start to spin again. but we are very close to the end point for this to continue much farther in earths histroy. The end point seems to be only about 1,000,000 miles or less form earths minimum distance from the sun. if the earth where some how jolted,knocked out of place during a magnetic pole reversal, we could end up in a difficult position. also the orbit of the earth around the suns has been recorded as changing and so they may put us in the same circumstance.

DwayneD.L.Rabon

chuuush
02-08-08, 12:28 PM
What would happen if the earth stopped rotating?
This reminds of a story I had read when I was younger. I don't now remember the source of that story. It was an Eastern myth I suppose. The myth says, "once there was a man who wished he could do anything he wanted. So God bestowed him this capability, Now anything he wanted or thought of would immediately come true. Once he learnt he could do anything just by saying it or thinking about it, he decided to try it. So he decided to stop the movement of the earth. The moment this taught passed his mind he and everything around him went flying into the sky. Everything from stones, houses, animals, trees, people, debris, mounts was passing by him and hitting each other and everything started to get destroyed. He was lucky to be fast enough think to himself "whatever happens, just let me survive this" right before he crashed the earth again. All but him died. He was sorry to wish for such a power, used his power to return everything to normal and then wish for his power to be taken.
This I suppose has some tracks of reality in it.

weed_eater_guy
02-08-08, 01:51 PM
Could be neat if we lived on a world in tidal-lock with the sun (i.e., one side of the earth always faces the sun). Because the side facing would probably be so hot and the side away so cold, we'd probably have to live around the terminator I suppose. We would, quite literally, be living in The Twilight Zone...

gdudea
10-19-09, 11:22 AM
if it stopped would we float or would be pinned down if the awnser is either please say y

I think we would just be floating. Gravity is made by the rotation and the mass in space (such as a planet). Wich in easier terms; the bigger the planet, the hevier things are. :D

gdudea
10-19-09, 11:25 AM
Could be neat if we lived on a world in tidal-lock with the sun (i.e., one side of the earth always faces the sun). Because the side facing would probably be so hot and the side away so cold, we'd probably have to live around the terminator I suppose. We would, quite literally, be living in The Twilight Zone...

There still would be seasons so that kinda stops that.

gdudea
10-19-09, 11:31 AM
What would happen if the world stopped spinning? also
What if the Earth rotated twice as fast?

Key things i need to know are what effect would gravity have on us in the two scenarios above.

if the earth would spin twice as fast we the gravity would be 2x harder. Lets say there is a 10 pound weight at normal (1) gravity 10 x 1 = 10. if the gravity would double the gravity would be 2. so the 10 pound weight would be 20 pounds. 10 x 2 = 20.

gdudea
10-19-09, 11:38 AM
Instantly or over time?

If the world stopped spinning instantly then we would be flying at a speed of 1,666 kp/h if you were at the equator, but that is faster than the sound barrier so you would be ripped to shreads before you understand whats going on.

gdudea
10-19-09, 11:39 AM
If the world spun in reverse then nothing will change (that i'm conserned about) but the stars and the sun on wich way they travle.

D H
10-19-09, 11:42 AM
I think we would just be floating. Gravity is made by the rotation of a mass of a object in space (such as a planet). Wich in easier terms; the bigger the planet, the hevier things are. :D
This is utter nonsense.

Dywyddyr
10-19-09, 12:15 PM
if the earth would spin twice as fast we the gravity would be 2x harder.
Rubbish.


but that is faster than the sound barrier so you would be ripped to shreads before you understand whats going on.
Also rubbish.

gdudea
10-19-09, 03:43 PM
This is utter nonsense.

I messed the wording up :eek:

gdudea
10-19-09, 03:51 PM
Rubbish.


Also rubbish.

Whats wronge with it? :confused:

Dywyddyr
10-19-09, 04:01 PM
Whats wronge with it? :confused:
The rate of spin of a planet does NOT increase or decrease its gravitational pull (except for perceived gravity - if it spins fast enough you'd get thrown off).
Most certainly increasing the rotational rate does NOT increase gravity.

And for the other, sound barrier or not has no bearing on "being torn apart".
Men have ejected at supersonic speeds and survived.

And your other statement: "Gravity is made by the rotation of a mass of a object in space (such as a planet). Wich in easier terms; the bigger the planet, the hevier things are."
Also rubbish.
Those two sentences are in no way linked in reality.
The rotation is not linked to gravity (as stated): and it's not size so much as mass - it's possible to have a large planet composed of not very dense material - hence it would have a relatively low gravity.

gdudea
10-19-09, 04:12 PM
you said "The rate of spin of a planet does increase or decrease its gravitational pull (except for perceived gravity - if it spins fast enough you'd get thrown off). "

We haven't flung off the planet even though were going at 40,000 kp/h. So then how fast does the Earth have to spin in order for people to fly off?

Dywyddyr
10-19-09, 04:23 PM
you said "The rate of spin of a planet does increase or decrease its gravitational pull (except for perceived gravity - if it spins fast enough you'd get thrown off). "
Should have written "The rate of spin of a planet does NOT increase or decrease its gravitational pull..." but that should have been obvious from the clause I appended.


We haven't flung off the planet even though were going at 40,000 kp/h.
40,000 kph?
How do you get that figure?
The equatorial circumference is 40,075.16 km and we do that in 24 hours = 1669.7983 kph.


So then how fast does the Earth have to spin in order for people to fly off?
Work it out: escape velocity is ~11 km/ sec (39600 kph), so we'd have have a "day" as short as 1.01 hours. ((24/39600)*1670)
Which also negates your supposition (based on what I wonder) that the faster the Earth spins the higher the gravity.

gdudea
10-19-09, 04:30 PM
40,000? oops i ment 1,666kp/h. Wronge number inserted.

[QUOTE=Which also negates your supposition (based on what I wonder) that the faster the Earth spins the higher the gravity.

Thats what i'v been saying. :mad: unless i'm getting something messed up.....this is one of the worst days ever. :(

Dywyddyr
10-19-09, 04:36 PM
Thats what i'v been saying. :mad:
No it isn't - "if the earth would spin twice as fast we the gravity would be 2x harder".
Post #35.

And again, the spin does not affect the gravity, it merely counteracts it with another force.
The Earth will still have a 1G pull regardless of spin rate.

gdudea
10-19-09, 04:38 PM
No it isn't - "if the earth would spin twice as fast we the gravity would be 2x harder".
Post #35.

And again, the spin does not affect the gravity, it merely counteracts it with another force.
The Earth will still have a 1G pull regardless of spin rate.

then what is the other force?

Dywyddyr
10-19-09, 04:45 PM
Inertia.
Usually called centrifugal (http://en.wikipedia.org/wiki/Centrifugal_force) force.

gdudea
10-19-09, 05:01 PM
Usually called Centrifugal force.

true. but what about the sound barrier? Even though people have bailed out at 726 mp/h i belive is the speed of sound, but what about going 2.3x faster than the speed of sound

Dywyddyr
10-19-09, 05:10 PM
true. but what about the sound barrier? Even though people have bailed out at 726 mp/h i belive is the speed of sound, but what about going 2.3x faster than the speed of sound
The sound barrier as the sound barrier isn't a problem it's more the absolute (relative to the atmosphere) speed.
Accelerating rapidly into the atmosphere, or frictional heating.

And bear in mind that the atmosphere would also probably be departing rapidly...
SO you could be doing 11 km/ sec relative to the Earth's surface (i.e. what would definitely be classed as supersonic), but if the atmosphere is moving with you then you won't suffer any ill effects on that count.

gdudea
10-19-09, 05:37 PM
with[/I] you then you won't suffer any ill effects on that count.

The atmosphere won't be moving with you. Have you given some thought to "Newtons First Law of Motion" to everything on earth?

Dywyddyr
10-19-09, 05:43 PM
The atmosphere won't be moving with you.
Really?
It would be moving with you for much the same reason - it's "attached" to the Earth as we are and moves with its rotation - that's why we don't have 1700 kph winds all the time.


Have you given some thought to "Newtons First Law of Motion" to everything on earth?
That's why we'd get thrown off - we'd continue to move at peripheral speed which is fast enough to overcome the gravity.

gdudea
10-20-09, 02:03 PM
but we are hevier so we will go faster then the wind. put your hand in front of you, move it as fast as you can to your right. What happends? You feel the air.

Dywyddyr
10-20-09, 02:09 PM
but we are hevier so we will go faster then the wind.
And? At no point did I say we'd move at the same speed.


put your hand in front of you, move it as fast as you can to your right. What happends? You feel the air.
Which has what to do with anything?

TBodillia
10-21-09, 01:24 AM
if the earth would spin twice as fast we the gravity would be 2x harder. Lets say there is a 10 pound weight at normal (1) gravity 10 x 1 = 10. if the gravity would double the gravity would be 2. so the 10 pound weight would be 20 pounds. 10 x 2 = 20.

Let's start with the law of universal gravitation:

F = G (M1 * M2)/r▓ Force equals the gravitational constant times the mass of the 1st object times the mass of the 2nd object divided by the square of the distance between them.

Where in that equation is angular velocity mentioned?

On to practical examples:
The Moon spins at about 1/28th speed of the Earth and yet is has about 1/6th of the gravity. Why? 1/6th of the mass.

Venus has a retrograde rotation, and a slow one at that. That means Venus spins backwards (from us, normal), slowly. Venus doesn't have anti-gravity. Venus is not throwing rocks off into space or having rocks float away. Venus has about the same gravity as us. Why? About the same mass.

More examples needed?

D H
10-21-09, 01:59 AM
More examples needed?
How about the Sun? It spins rather slowly, about one rev per 25 days. Yet "surface" gravity on the Sun is about 28 g. Could this possibly be because the Sun is a tad more massive than the Earth?

gdudea
10-21-09, 05:05 PM
Which has what to do with anything?

you can feel the air.

AlphaNumeric
10-22-09, 12:13 PM
The Moon spins at about 1/28th speed of the Earth and yet is has about 1/6th of the gravity. Why? 1/6th of the mass.Actually its about 1/81 the mass but the smaller radius slightly offsets that.

Dywyddyr
10-22-09, 03:39 PM
you can feel the air.
Yep.
And if I put my hand in the freezer I can feel an ice cube.
Which also has nothing to do with gravity or being ripped apart or the Earth stopping turning.

superstring01
10-22-09, 05:53 PM
if it stopped would we float or would be pinned down if the awnser is either please say y

Gravity comes from the mass, not the spin.

Edit: Sorry. Already answered.

~String

TBodillia
10-23-09, 01:08 AM
Actually its about 1/81 the mass but the smaller radius slightly offsets that.
You know, mistakes like that is why I wish I had a calculator with a registry tape. I'm curious what numbers I punched in to get 1/6th mass.

John Connellan
10-24-09, 06:30 PM
So does this mean if the earth stopped spinning and there were no centripetal force would we still be able to walk on earth, and would buildings still stand? Is a body that stands on the north pole heavier than on the equator?


Many people have the idea in their heads that the centripetal acceleration of an object on the earth's surface is huge since they are travelling at a linear velocity of about 1600 kph. Surely we should be flung off the earth if it suddenly stopped spinning.

However, they forget to remember that we are a long way from the center of this rotation. Because the radius of the earth is so large, the angular velocity of objects on the surface is quite small and the resulting centripetal acceleration is also small - much smaller than g.

gdudea
10-26-09, 09:50 PM
I know the magnetic fields do something bad if the world stopped spinning, what is it? I think i might know but i'm not sure.

Xylene
10-27-09, 12:08 AM
Alright, let's go with that map that was supplied of the non-spinning Earth scenario from the article (page 1); an equatorial continent, with oceans at each pole. Given that the atmosphere will stay in place (because the Earth's gravity will not change) the sun's heat will be shifted around by the winds.

Although there will be a significant increase in the temperature on one side of the planet and a corresponding reduction on the 'night side' of Earth, the heat-transfer by wind will ensure that these extremes will not as extreme as might be expected.

Assuming that the Earth still rotates on its usual angle and the Arctic and Antarctic Circles still exist, these areas (the new polar seas) will be the only places where people can stay living on the surface in reasonable comfort--presumably in floating communities on the polar oceans, or around the coasts thereof. The other alternative are subterranean communities on the continents in either the cold or warm hemispheres.

John Connellan
10-27-09, 04:09 AM
Assuming that the Earth still rotates on its usual angle and the Arctic and Antarctic Circles still exist, these areas (the new polar seas) will be the only places where people can stay living on the surface in reasonable comfort--presumably in floating communities on the polar oceans, or around the coasts thereof. The other alternative are subterranean communities on the continents in either the cold or warm hemispheres.

What angle is this? Didn't you say that the earth would not be rotating? Do you mean that it rotates once a year so keeping the same side towards the sun at all times?

Anyway, the old polar regions are not the only places we could live. We could live aywhere around the new north-south equator without radiation being excessively high. The weather would, however, still be extreme to say the least and I wouldn't like to be caught in one of those strong heat transfer winds!

Xylene
10-28-09, 04:15 AM
What angle is this? Didn't you say that the earth would not be rotating? Do you mean that it rotates once a year so keeping the same side towards the sun at all times?



Anyway, the old polar regions are not the only places we could live. We could live aywhere around the new north-south equator without radiation being excessively high. The weather would, however, still be extreme to say the least and I wouldn't like to be caught in one of those strong heat transfer winds!

Woops...my apologies--I should have made that clearer.
I'm assuming that the angle of rotation of the Earth will remain the same even when the planet has been trapped in a non-rotating mode. I must agree that the heat-transfer winds would be savage. I suggest that while we could live in the most extreme environments, the most comfortable place would be the high latitudes of each hemisphere.

John Connellan
10-31-09, 05:49 PM
. I suggest that while we could live in the most extreme environments, the most comfortable place would be the high latitudes of each hemisphere.

Although, to be fair, I don't think we could live on a continental area on the dark side (if the earth kept the same side towards the sun throughout the year).

If temperatures often get to -80 C in an Antarctic winter, you can only expect temperatures to drop to at least -140 C over there :eek:

Imagine being able to experience that, wonder what kind of cloths you would need!

Xylene
10-31-09, 09:26 PM
There would be certain advantages to underground cities in such a situation...:)

gdudea
11-01-09, 01:31 AM
There would be certain advantages to underground cities in such a situation...:)

Even so, where would you get the sunlight you need?

Rockwolf
05-31-11, 06:29 PM
Quite simply yes everything would die.

First of all the earths magnetic field would collapse. This is due to the dynamo effect present in the earths core. If the earth stops spinning, so does the core. When the core stops spinning the magnetic field collapses and the earth is barbequed by the sun.

Second the moon would not be able to hold a stable orbit around the earth. The planets hold their orbits due to the fact that the sun rotates creating a gravity well. If the earth stops spinning the moon will either:

1. spiral into earth and crash into it.
2. spiral out of orbit.

Third the earth would lose it's atmosphere. In the NGEO documentary they claim that the atmosphere would settle on the poles. Untrue. As the earth stops spinning, it would slowly lose part of it's gravitational field and even a small change in that would cause the outer atmosphere to bleed off into space.

Not that any of this is even remotely possible in the realm of physics, but that is what would happen.

James R
05-31-11, 07:43 PM
Quite simply yes everything would die.

First of all the earths magnetic field would collapse. This is due to the dynamo effect present in the earths core. If the earth stops spinning, so does the core. When the core stops spinning the magnetic field collapses and the earth is barbequed by the sun.

Possibly.


Second the moon would not be able to hold a stable orbit around the earth. The planets hold their orbits due to the fact that the sun rotates creating a gravity well.

This is wrong.

Gravity is not caused by spin, but by mass. Non-spinning objects (e.g. you) still create and respond to gravity.


Third the earth would lose it's atmosphere. In the NGEO documentary they claim that the atmosphere would settle on the poles. Untrue. As the earth stops spinning, it would slowly lose part of it's gravitational field and even a small change in that would cause the outer atmosphere to bleed off into space.

No. The Earth's gravitational field is unaffected by spin. Only mass counts.

eclaire291
10-11-11, 12:56 PM
I know that this question was posed as a hypothetical, but I'm just wondering if it would be possible for this to ever really happen? Are there any known planets that do not spin? Sorry, I just got to wondering after watching an episode of "Aftermath" on National Geographic in which the Earth stopped spinning.

billvon
10-11-11, 01:17 PM
I know that this question was posed as a hypothetical, but I'm just wondering if it would be possible for this to ever really happen?

Yes. Planets deform when they spin due to the tides caused by the primary and by any moons. This requires energy, thus energy is lost constantly. This means the planet slowly slows down - although this will take billions of years.


Are there any known planets that do not spin?

Pluto and Charon have become "tidally locked" - they have both been slowed so much by tides that they no longer spin relative to each other. (They do, however, spin around a common center, so they still spin as a system at about once every six days.) If this happened to the Earth the length of the day would become 28 24 hour days long.


Sorry, I just got to wondering after watching an episode of "Aftermath" on National Geographic in which the Earth stopped spinning.

It would certainly turn the Earth into an interesting place.