Title text: Sailor Moon's head exploded once' and 'Some men have explosive orgasms' both work for the Great Lakes from west to east (Paddle-to-the-Sea order).
A mnemonic is any trick that makes memorization easier. For memorizing a sequence of names, a common type of mnemonic takes the initials of the sequence and invents another phrase to them. For example, the order of operations goes Parentheses, Exponentiation, Multiplication and Division, Addition and Subtraction, and the traditional mnemonic goes Please Excuse My Dear Aunt Sally. To make them more memorable, mnemonics are usually quite silly and often vulgar. In this comic, Randall invents various scientific mnemonics, some of them as suggested replacements for traditional ones.
The category is listed at the top of the box, the members are listed below that. Then there is the traditional mnemonic that children are usually taught in school to help them remember. Below the comic is one or two options for new mnemonics suggested by Randall. The top one is illustrated in the frame.
- SI Prefixes are the prefixes for the systems of units from large to small and since there are so many, the mnemonic needs two lines.
- Karl Marx, as visible in the comic, was a German philosopher and economist who, among other things, invented the ideas of socialism and communism. Central to his ideas was the dictatorship of the proletariat, or the working class achieved by an uprising of the lower class, which taken literally could be done using zeppelins.
- Microsoft's Zune was a failed mp3 player that Microsoft brought to market. It never caught on.
- Taxonomy is the science of identifying and naming species. Katy Perry, portrayed in the panel, is an American pop music singer, whose popular songs are ones like "Fireworks" or "I Kissed A Girl".
- In the geologic periods frame, the illustration is of a month's worth of "the pill" a common contraceptive.
- In Resistor Color Codes, Glenn Beck is in the illustration. Beck is a far-right conservative commentator in the US, who used to have a show on the Fox News Network.
- The sign Glenn Beck is holding is a reference to 966: Jet Fuel.
- The prevailing mnemonic for resistor color codes is pretty terrible (and memorable), hence Randall's comment "none I care for".
- Be Bold is a Wikipedia credo. Respect Others may be a reference to Assume Good Faith, another Wikipedia philosophy.
- In the Planets frame, the illustration is of Mary and Joseph, who in the story of the Birth of Jesus in the Bible, were mother and father to Jesus. However, Mary's conception of Jesus was from God and Mary was still considered a virgin. This mnemonic shows Joseph not really believing that story. Ironically the upstairs neighbour could have multiple meanings as you can't get more upstairs than heaven and thus God. Given the stance most xkcd comics take on religion, it is likely a corporeal neighbor that is being suspected, but it is curious that a neighbor of the upstairs variety is specifically referenced especially given the lack of urban density in the time of Christ.
- Most traditional Planets mnemonics include Pluto, which was "officially" considered a planet before 2006.
- The Great Lakes mentioned by the title text are Superior, Michigan, Huron, Erie, and Ontario
- XKCD Presents:
- Some New Science Mnemonics
- (Pattern goes:
- Traditional mnemonic
- Contents of frame
- New mnemonics)
- Order of Operations
- Parentheses, Exponents, Division & Multiplication, Addition & Subtraction
- Traditional: Please Excuse My Dear Aunt Sally
- [Person having a shark delivered to his laptop.]
- Please Email My Dad A Shark
- People Expect More Drugs And Sex
- SI Prefixes
- Big: Kilo, Mega, Giga, Tera, Peta, Exa, Zetta, Yotta
- Milli, Micro, Nano, Pico, Femto, Atto, Zepto, Yocto
- [Graph of the declining profits of the Zune.]
- [Karl Marx delivering a number of zeppelins to a bunch of confused proletariats.]
- Big: Karl Marx Gave The Proletariat Eleven Zeppelins, Yo
- Small: Microsoft Made No Profit From Anyone's Zunes, Yo
- Kingdom, Phylum, Class, Order, Family, Genus, Species
- Traditional: King Philip Came Over For Good Sex
- Katy Perry: I'm not sure who doubts this, really.
- Katy Perry Claims Orgasms Feel Good Sometimes
- Kernel Panics Crash Our Family Game System.
- Geologic Periods
- (Precambrian), Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian, Triassic, Jurassic, Cretaceous, Paleogene, Neogene
- Traditional: [I never learned one.]
- [A month's set of birth control pills.]
- PolyCystic Ovarian Syndrome Does Cause Problems That Judicious Contraceptives Partially Negate
- Resistor Color Codes
- Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gray, White
- Traditional: [none I care for]
- [Glenn Beck holding the traditional "Nanobot Vaccine Chemtrail 9/11" sign.]
- "Big Brother Reptilian Overlords", yelled Glenn, "Brainwashing Via Ground water!!";
- Be Bold, Respect Others; You'll Gradually Become Versatile, Great Wikipedians!
- Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
- Traditional: My Very Excellent Mother Just Served Us Nachos
- [A pregnant Mary attempting to explain things to an incredulous Joseph]
- Mary's "Virgin" Explanation Made Joseph Suspect Upstairs Neighbor.