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Originally written by *i:

The net consequence is that magnetic fields can do no net work, only electric fields can*.

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Something just occurred to me: What you're saying is limited to simple Newtonian equations, right?

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Because this is a cross product, the force is perpendicular to both the motion of the particle and the magnetic field. It follows that the magnetic force does no work on the particle; it may change the direction of the particle's movement, but it cannot cause it to speed up or slow down.

This might give you pause: Simple bar magnets seem to be entirely able to pick up small metal objects, which certainly seems to require that they do work on those objects. As David Griffiths points out in his textbook Introduction to Electrodynamics, this law is absolute - the magnetic field doesn't do any work. However, quite like the normal force of an inclined plane, which also can't do work, the magnetic field can redirect the efforts of existing forces, and then those forces can indeed do work in the relevant direction.

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I don't know that we have the capability to distinguish different animals from one another. It is currently programmed to only shoot blue objects. But that's because the really good programmers aren't working on it. This robotics club does some serious stuff, such as the DARPA Grand Challenge, as well as national UAV, unmanned sub, and unmanned ground vehicle competions, where they have to recognize complex obstacles and avoid them.

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Originally written by WiKiSpidweb:

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Our current simplistic setup works by taking the data from the camera and turning it into a 2D array of RGB values, the centroid of the blue values is found and the turret is moved until the centroid is in the center of the camera, which is aligned with the barrel of the gun. This is pretty much the most basic way imaginable to visually track something, and adjustments need to be made for situations where there are multiple objects in view, which confuses the above mentioned algorithm.

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Originally written by Wikipedia:

This might give you pause: Simple bar magnets seem to be entirely able to pick up small metal objects, which certainly seems to require that they do work on those objects. As David Griffiths points out in his textbook Introduction to Electrodynamics, this law is absolute - the magnetic field doesn't do any work. However, quite like the normal force of an inclined plane, which also can't do work, the magnetic field can redirect the efforts of existing forces, and then those forces can indeed do work in the relevant direction.

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Classical spinless moving charges can produce magnetic moments, leading to the paradox posed above, in which magnetic fields do no work but do enable work to be done. But relativity and quantum field theory together give particles intrinsic magnetic moments, and so real particles do experience non-Lorentz forces from magnetic fields, which can do work.

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Originally written by Robinator, #034:

I made a flute that played itself. Needless to say, it totally blew.

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Originally written by MagmaDragoon:

Inventions? I would make an implant: a computer IN your arm that recarge itself with your physical energy.

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