View Full Version : Equivalent resistance
http://xkcd.com/356/
I'm clueless, yet curious.
who knows, who cares, its unmeasureable :)
its just a cartoon, enjoy the joke on the physicist ;)
Dave
Averagesupernova
Mar23-11, 07:23 PM
Well if you really want to know, build it. You don't need to build it to infinity though, just 10 resistors or so in each direction should get you pretty close. Then measure the voltage across each resistor to see how the network carries it.
It has to approach some value and certainly has to be mathematically expressible.
On a side note, the comic is pure genius. :D Guess I got sniped as too... well, not that I'm dead, but I certainly caught some flak since it's 5AM and I'm still actively waiting on a reply here.
Proton Soup
Mar24-11, 12:22 AM
yeah, the trick is find the pattern. see if you can make an infinite series out of it and see if it converges. something along those lines. and i'm sure it does, because if you measure between two points on a metal sheet, it won't be zero no matter how big the sheet gets. but my head hurts, and i'm lazy.
we got stuff similar on physics exams years ago, but smaller, say between the diagonals of a cube where the edges are resistors and the corners nodes. there it becomes a symmetry trick. or, mesh/nodal analysis when you get to circuits courses.
Already discussed in this thread: 206096 (now locked 'cause it's too old).
Proton Soup
Mar24-11, 09:48 PM
^ugly.
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