explain xkcd - User contributions [en]

567: Urgent Mission

2013-07-26T16:12:20Z

71.57.148.227:

{{comic
| number = 567
| date = April 10, 2009
| title = Urgent Mission
| image = urgent_mission.png
| titletext = Sure, we could stop dictators and pandemics, but we could also make the signs on every damn diagram make sense.
}}

==Explanation==
Benjamin Franklin, was one of the Founding Fathers of the United States. Aside from uniting most of America against Britain's totalitarian 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, abolitionist ideals, and his image on the $100 bill. For the purposes of this comic, Ben Franklin also created the lightning rod and discovered the fundamentals of electricity (such as positive and negative charges, as well as the conservation of electric charge.

When Benjamin Franklin first wrote down his notes for electricity, he defined a positive charge as a charge caused by glass rubbing on silk, and a negative charge as a charge left when fur rubs on rubber. This definition for electrical charges still exists today, including in electrical diagrams (as the title text notes). The problem is that as our knowledge of electrical circuitry increased, we realized that the flow of a current, from negative to positive, is not how electrons move in a wire. Rather, it is how the absence of electrons move in a wire. The flow of electrons themselves go from positive to negative terminals, which is not the first thought that comes to mind in terms of electrical concepts. It's a confusing concept to many fledgling engineers, and one that the time-traveler considers a greater priority. It also adds minus signs in a few physics formulas.

==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.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring real people]]

Urgent Mission

2013-04-21T01:53:40Z

71.57.148.227: Redirected page to 567: Urgent Mission

#REDIRECT [[567: Urgent Mission]]

567

2013-04-21T01:53:28Z

71.57.148.227: Redirected page to 567: Urgent Mission

#REDIRECT [[567: Urgent Mission]]

567: Urgent Mission

2013-04-21T01:52:48Z

71.57.148.227: Created page with "{{comic | number = 567 | date = April 10, 2009 | title = Urgent Mission | image = urgent_mission.png | titletext = Sure, we could stop dictators and pandemics,..."