567: Urgent Mission

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Urgent Mission
Sure, we could stop dictators and pandemics, but we could also make the signs on every damn diagram make sense.
Title text: Sure, we could stop dictators and pandemics, but we could also make the signs on every damn diagram make sense.

[edit] Explanation

Benjamin Franklin was one of the Founding Fathers of the United States. Aside from uniting most of his country against Britain's heavy-handed rule, he was also an author, printer, musician, politician, postmaster, inventor, scientist, and diplomat. Some of his legacies include bifocals, the Franklin stove, an odometer for a horse-drawn carriage, the almanac and abolitionist ideals. He has since been honored with the use of his image on the $100 bill. For the purposes of this comic, Franklin also created the lightning rod and discovered the fundamentals of electricity, such as positive and negative charges, as well as the principle of conservation of charge.

When Franklin first wrote down his notes for electricity, he defined a positive charge as one left on a glass rod by rubbing it with silk, and a negative change as one left on rubber by rubbing it with fur. Without realizing it, this meant that he had assigned a negative value to the charge on the electron, later identified as the fundamental carrier of electrical charge.

In an electrical circuit, we envisage the charge to be flowing from positive to negative. This is analogous to energy flowing from a region of high temperature to one of low temperature, or a fluid moving from an area of high pressure to one of low pressure. However, because an electron is negatively charged, the actual flow of electrons is in the opposite direction, from negative to positive. This reversal of the natural expectation has caused unnecessary confusion to many fledgling engineers.

Time-travelling Cueball believes that reversing this decision has a higher priority than, say, avoiding the robot apocalypse. Rubbing a glass rod with silk removes electrons from the rod, and defining the resulting charge of the rod as negative would have thus assigned positive charge to electrons. Nothing, could ever be the same.

This would mean that protons would have been assigned a negative charge, and a different name would have been used for the positron. Negatronic brains, anyone? Of course it is too late to change now. But a time traveler...

[edit] Transcript

[Cueball steps out of rift. Benjamin Franklin is sitting at his desk with quill and parchment.]
Cueball: Benjamin Franklin?
Franklin: Yes?
Cueball: I bring a message from the future! I don't have much time.
Franklin: What is it?
Cueball: The convention you're setting for electric charge is backward. The one left on glass by silk should be the negative charge.
We were going to use the time machine to prevent the robot apocalypse, but the guy who built it was an electrical engineer.
Comment.png add a comment!


The explanation is backwards. Current is defined as the flow of *positive* charge, thus moving from positive to negative terminals. In most cases, the current is actually electrons, which are moving from the negative terminals to the positive. 16:48, 27 June 2013 (UTC)

Hopefully fixed. This was hard to write clearly. 01:43, 11 January 2014 (UTC)
I might be completely mistaken but I've thought that the reason why the positive and negative terminals are assigned as they are originated from observing the electric current passing through the solutions of salt. In the said solutions the current consists of the positively charged ions that get deposited onto the negative electrode, while the positive electrode slowly dissolves. This naturally makes one think that the electric current carries the charged particles from the positive to the negative electrode. Of course it might be that I've completely forgotten what I've been taught in school and gotten everything wrong. 01:50, 29 January 2014 (UTC)
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