# Difference between revisions of "199: Right-Hand Rule"

 Right-Hand Rule Title text: To really expand your mind try some noncartesian porn. Edwin Abbot Abbott has nothing on "Girls on Girls in Tightly Closed Nonorientable Spaces"

## Explanation

 This explanation may be incomplete or incorrect: This needs explanations for the individual methods. A more in-depth explanation of the title text would also be great.If you can address this issue, please edit the page! Thanks.

The right-hand rule is a mathematics and physics trick to learning how to find the cross product of two Cartesian vectors in three dimensions. First, position your right arm in the direction of the first vector (in the example diagram in the comic, this is to the left). Then, curl your fingers in the direction of the second vector (out of the page/screen, in the example). Now point your thumb perpendicular to the other fingers, and it will point in the direction of the cross product of those two vectors (upwards, in the example). Note that reversing the order of the two vectors also reverses the direction of the cross product.

The book rule is an actual alternative to the right hand rule that might be useful to some physics students doing exercises out of their textbooks. However, since this is xkcd, things are going to get silly.

The gun rule also technically works, but it would be extremely impractical, expensive, and dangerous to use and fire a loaded gun every time you want to find the result vector. It would also be very awkward to hold the gun in line with the vectors.

The body rule is for males only, which is very limiting for a rule that is meant to make math and physics problems easier. With the right arm oriented along one vector and the legs along the second, the result vector is found along the penis of the person, which is conveniently erected by watching porn.

The title text refers to Edwin Abbott Abbott, author of the book Flatland, a story about a two dimensional world.

Orientability is a property that refers to a space with continuously varying surface normals, which are essentially just vectors that are perpendicular to the surface of the space. Nearly every space commonly encountered is orientable; this is likely why the porn is referred to as mind expanding and superior to Edwin Abbot Abbott's work.

## Transcript

[Picture of a right hand with fingers curved, thumb pointed away, with axes drawn to demonstrate the right-hand rule of physics.]
Alternatives to the Right-Hand Rule in vector multiplication:
[A slightly-open book with labeled axes drawn on.]
Book Rule: Open the front cover along the first vector and the back cover along the second. The result vector is along the spine, out the top.
[A handgun with axes.]
Handgun Rule: Point the grip along the first vector and rotate it so that the second vector is on the safety latch side. Fire. The result vector is toward the bullet holes.
[A person with right arm extended.]
Body Rule (males only): Point your right arm along the first vector and your legs along the second, then watch some porn.

# Discussion

There's also the right hand rule on urban dictionary, although it's applied slightly differently, and it only has one input parameter. Davidy22 (talk) 03:44, 30 October 2012 (UTC)

I expanded the explanation to cover the erection joke. 184.66.160.91 02:12, 27 August 2013 (UTC)

Can anyone explain "Girls on Girls in Tightly Closed Nonorientable Spaces"? What is that, lesbians in a box? What is a nonorientable space? Swordsmith (talk) 02:14, 28 November 2015 (UTC)

A non orientable space is, IIRC, a shape like a Möbius strip, in which has a sort of topological " handedness." Or maybe that's an orientable space. I'm pretty sure it's non orientable.

As far as noneuclidean porn goes though, I have a fetish for fractals. Just pull up a sexy fractal zoom and we're good to go. But I'm cisfemale. No dick. X'D International Space Station (talk) 09:18, 27 April 2016 (UTC)