Which direction does a twister twist in, clockwise or counter-clockwise? does hemisphere change that?
414354
In the Northern Hemisphere, a tornado or twister twists counter-clockwise. In the Southern Hemisphere is clockwise. This is due to the Coriolis effect, caused when objects (in this case air) moves over the rotating earth. The air flows towards the twister, but curves to right (relative to the direction it is flowing). It is easier to visualize if you think about some air flowing straight north to a twister. Since the earth's surface is moving faster towards the east where it started, it carry on some of the momentum and curve to the east (right of the northerly direction it was flowing). This will tend to cause the air to miss the twister, but he extreme low pressure will allow the higher pressure around it to bend the flow towards the funnel, but the air will have the angular momentum of moving the right as it moves in, thus creating the counter-clockwise twist. In the Southern Hemisphere, a flow from the south towards a twister will be coming from a place closer to the earth's axis, and thus will be moving East more slowly than the land under the twister, so it fall behind (to the West) as it approaches, resulting, through the similar process as described above, in a clockwise twist.
192182
It's because left and right are relative terms, while up and down refer more to absolutes.  If were facing east looking into a mirror, our right hand would be south, and our left hand north.  Referred to north and south, there is no inversion--move your "north hand" and the image's "north hand" moves; move your south hand and the images south hand moves.  The problem is that left/right is a special sort of orientation that is centered from ourselves and distinguishes from two symmetrical sides of ourselves.  You right hand looks like the reflection of you left hand, but when you look at the reflection of your left hand, that reflect is still on *your* left.  If you imagine that the image reflected is some different person, and you try to set up a left/right orientation with resepct to the person in the mirror, it will be backwards--but that's only because it is erroneous to think that the reflection of your right hand is your reflection's left hand.  It isn't; it just looks like a left hand because our bodies display left/right symmetry.  If your head looked like the mirror image of your feet, you might make the same mistake, but the body does not display any manner of top/bottom symmetry.
1119487
It doesn't. Go south of the equator and you will see it spins clockwise.
48008
Hick_Ninja's answer is correct if as you say the current is flowing in one direction upward. The right hand rule will give you the answer. Here is an illustration of the right hand rule and how to apply it: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magfor.html\n\nIf however, you are using an Alternating Current, then the flow direction reverses with some frequency. The right hand rule will still work, but the field is reversing. Here is a good illustration of that:\nhttp://www.sunblock99.org.uk/sb99/people/DMackay/ac.html\n\nThe problem with clockwise and counterclockwise is that they are relative to point of view. So yes, it is counterclockwise in the horizontal plane, but only if looking down on it. Here's an illustration of that:\nhttp://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/wirfor.html#c1
356220
Depends on your point of view. If you're hovering above the North pole, the earth rotates counter-clockwise. If you're hovering above the South pole, it rotates clockwise.
452210
Egads.  It's been quite awhile.  I remember some papers at SIGGRAPH a decade or so ago on this topic.\n\nAlright, here's a stab at the explanation.\n\nWith Euler mechanics or Euler angles, there are three reference angles: yaw, pitch, and roll. It is possible to rotate an object using these three reference angles such that two line up causing the inability to do an arbitrary rotation.  Say you roll to the right 90 degrees and this lines up the yaw axis with your pitch axis -- gimble lock results.\n\nWith quaternions, you don't have three reference angles.  You have only one plane and an arbitrary axis of rotation.  Each move creates a new plane and axis of rotation.  As such, there are no additional axes of rotation with which to collide because there is only one axis of rotation and it's position is arbitrary where as with Euler angles, the reference angles are fixed.\n\nI don't know if I've done it justice, but maybe this explanation and the references below will help you stitch together an understanding.
234935
Short answer, they are called "tornado;" as you will see below, tornadoes usually rotate in a counter-clockwise direction in the northern hemisphere, clockwise in the southern.  In the rare event of it spinning in the opposite direction, which I believe was the nature of your question, it is called an "anticyclonic tornado."\n\nTornadoes normally rotate in a cyclonic (counterclockwise) direction in the northern hemisphere, as the warm air in which thunderstorms usually form sweeps north and jet streams come from the west, creating a situation in which the storms rotate. In the northern hemisphere, this rotation is counterclockwise, and in the southern hemisphere, clockwise. The tornadoes usually rotate the same way. Sometimes opposite direction swirls develop under a thunderstorm. About 1 in 100 tornadoes in the northern hemisphere rotate in an anticyclonic direction.\n\nI hope this helps.
591725
As a rule, if you are right handed, your right hand is the hand you project with, the left is the one you receive with.  If you're left handed, it's the other way.  So, it really depends on what you're trying to do.
356086
it depends whether u live north or south of the equator. the culprit is called coriolis force. it is proportional to omegaXv where omega is the eaths angular momentum. since its a cross product and v is different in north and south. the direction (clockwise or anti) is thus different.
886860
When you look at yourself in the mirror the right side of your reflection is to the right of the mirror, and so on left to left, top to top...  What is reversed is front to back.  If you are looking north your reflection is looking south.  Since you and your reflection are looking in opposite directions but the hands are on the same sides your reflection appears left handed because you expect the right hand of a person facing you to be on the opposite side.
668041
Large scale flows depend on the Coriolis effect, which make the motion turn differently in each hemisphere. Therefore cyclones, hurricanes (though they are rare in southern hemisphere) and such events turn clockwise in the southern hemisphere and counterclockwise in the northern hemisphere. As the spatial scale diminishes, the Coriolis effect loses importance. For tornadoes, for instance, it is still sufficient to make 98% of them to turn clockwise in the southern hemisphere and counterclockwise in the northern hemisphere. But, in 2% of the cases they turn differently.\nDust devils are small enough so that they can turn either way, independently of hemisphere.\nOf course, the water flowing down your sink is a very small-scale process. Coriolis effect makes no difference in that case.\nTherefore, it can go either way, both in Australia and in North America, depending only on the sink geometry.
945495
The idea that water drains counter clockwise in the northern hemisphere, and clockwise in the southern hemisphere is wrong. It is a popular misconception, and is based on something called the "coriolis force", which is kind of complicated to explain, but has to do with the spinning of the earth. It is true that the coriolis force would influence a liquid in the direction it drains, but the force is TINY compared to the other forces present in the liquid. The way water drains - whether clockwise or counter clockwise - is based mainly on the intial direction of the water in the container, not whether it is in the northern or southern hemisphere. So in short, at the equator, it will drain in either direction, depending on the initial direction! Hope this helps!
227951
Contrary to legend, it depends on the sink - not the hemisphere. The Coriolis force (which makes large scale currents and weather patterns turn clockwise in the Northern hemisphere and counter-clockwise in the Southern hemisphere) is really too small to matter in a sink/toilet. The geometry of the sink and the motion of the water before you pull the plug plays a much larger role.
49342
Some will say the Coriolis force (one of the fictitious forces that we observe because we live in a noninertial rotating frame), and predict that it will swirl clockwise in the southern hemisphere. However, these forces are overcome by all kinds of other geometric effects and residual motion etc. \n\nFor example, fill a sink with a few inches of water, and swirl it with your hand, either clockwise or anticlockwise. Wait for a few minutes until you are sure that the water is still. Then carefully drop in a drop or two of food coloring and watch. The water will remain in motion for hours from your stirring. When you remove the stopper, you can create a bias towards an anticlockwise or clockwise drain vortex. The shape of the drain can also influence the direction of this fluid motion. \n\nThe flushing of a toilet is a very vigorous event, and so it will have a large effect on the direction of fluid motion, along with many other factors.
1021502
The shape and direction of the twist is given by Coriolis effect, which  says since everything is falling to the center of earth, and it is spinning, there developes a curve, just like the one you see on your toilet, as opposite of the one you'd see in other toilet in southern hemisphere (if you are in the northern one)
680175
True. It is called the coriolis effect. It causes moving objects to drift sideways on their courses. This causes hurricanes to rotate. In the Northern hemisphere, the shift is to the right, in the Southern hemisphere it is to the left.
1126649
Yes, everything's upside down from down under!\n\nIf you're facing south looking at an early crescent setting in the northern hemisphere, the Moon is on your right, and the Sun is further to the right (west), so the right (west) side of the Moon is illuminated.  From the southern hemisphere, you're facing north, and west is on your left.  The western side of the Moon is still illuminated, but now you see it on the left. The Moon, of course, appears upside down.