The Dilemma: For reasons that are really none of our business, you’re extremely curious about nuclear reactions. Hey, that’s cool. We’re here to help.

People You Can Impress: nuclear physicists, environmental protesters, and just by correctly pronouncing NEW-clee-er, some American presidents

The Quick Trick: Fusion fuses elements lighter than iron. Fission divides elements heavier than iron.

The Explanation:
These two forms of reaction are called nuclear because the big stuff (that’s a technical term) all happens inside the nucleus of an atom.

Let’s put it in the simplest terms: Fusion works by smashing atomic nuclei together to create heavier nuclei. In order to make this happen, you have to heat things up a bit—say, a few million degrees Celsius. Fusion is promising as an energy source (and potentially dangerous) because it’s exothermic—it produces more energy than it requires to start it and is therefore self-sustaining. How much energy can fusion produce? Well, our sun’s been working for several billion years just fine on fusion.

Fusion is difficult to achieve because of something called the coulomb barrier. This is the energy required to overcome the electrostatic force that repells two nuclei from each other. What makes fusion tricky is that the best fuels, the ones with the lowest coulomb barriers, are the least stable. They are isotopes of hydrogen—deuterium (2H) and tritium (3H)—so named because they have two and three neutrons in their nuclei, respectively. We are not yet able to create a fusion reaction and contain it to use as energy. In fact, the ones we’ve created that aren’t contained are called hydrogen bombs. This has physicists looking for an alternative that requires much less energy to start and contains the Holy Grail of nuclear science known as “cold fusion.”

Fission, on the other hand, is the complete opposite: Very large nuclei are split to make smaller ones, releasing energy (and a boatload of radiation) in the process. Again, the best fuels are the most unstable: Isotopes like uranium-235 or plutonium-239 don’t occur naturally. Fission is used both for nuclear power plants and nuclear bombs.

To get fission going, you bombard the nucleus with a free particle, like a neutron or photon. The nucleus splits, releasing energy and more neutrons. If the split produces enough neutrons to keep the reaction going, it increases exponentially, and you reach critical mass.

Cold, Hard Facts
In 1989, two researchers at the University of Utah held a press conference and made a stunning announcement: They’d achieved nuclear fusion at room temperature, which offered the promise of an endless supply of cheap energy to the entire world. One problem: The two researchers had actually, as it turns out, not achieved fusion at room temperature. They hadn’t achieved it at all. In the years since, neither the original duo (who still claim the announcement wasn’t a hoax) nor other researchers have managed to replicate the initial results.

The Dilemma: Either you’re a rabid AC/DC fan in search of lyrical meaning or you’ve got some pressing need to blow something up. Either way, we’ve got your answer.

People You Can Impress: demolition experts, mustachioed villains from silent movies, and Wile E. Coyote

The Quick Trick: If it’s a white powder found in sticks, it’s dynamite. If it’s a yellow crystal, it’s TNT. Use this little mnemonic to remember dynamite’s inventor: “Winning a Nobel Prize would be dynamite!” The alternative, that winning would be TNT, just doesn’t make any sense.

The Explanation:
A lot of people use these two terms interchangeably, and the common misperception is that TNT is the chemical name and dynamite is the colloquial term. But like any good misperception, that’s just plain wrong.

We’ll start with dynamite. Patented in 1867 by the Swedish chemist Alfred Nobel (as in Nobel Prize), dynamite was discovered when old Alfie was looking for a way to make nitroglycerin more stable and less prone to, well, exploding in your face. By combining nitroglycerine with diatomaceous earth (the ground-up shells of microscopic diatoms, today used as a filtering agent in swimming pools) and sodium carbonate (found in baking soda and soaps), Nobel took explosives in a whole new direction. And because it was stable and wouldn’t explode from jiggling, like nitroglycerin, dynamite was initially marketed as Nobel’s Safety Blasting Powder. (Well, it wasn’t that safe; an explosion at the family factory killed Alfred’s brother Emil.) Nobel used the huge profits from his dynamite patent to endow the Nobel prizes, one of which is, ironically,for peace.

As for TNT, it’s also a high explosive, but it ain’t dynamite. TNT is a yellowish compound with the chemical name trinitrotoluene(try-night-row-TALL-you-een), which is somewhat easier to remember than its chemical formula, CH 3C6H2(NO2)3. TNT was discovered in Germany in 1863 by Joseph Wilbrand. Although not quite as powerful as dynamite (and harder to detonate), the main benefit of TNT is that it’s even more stable than dynamite (Wilbrand, for instance, never lost a single brother to an explosion). Also, TNT can be melted down and poured into shell casings. On the downside, however, TNT is extremely toxic.

While TNT packs plenty of bang by itself, it’s often mixed with other things. A TNT and ammonium nitrate cocktail will get you amatol, a military explosive. Remix those two and add some powdered aluminum, and you’ll get ammonal, a common industrial explosive.

AC/DC
The confusion between TNT and dynamite isn’t helped by popular culture. The two are routinely used interchangeably in movies. And in the song “TNT” by AC/DC, deceased lead singer Bonn Scott declares “I’m TNT, I’m dynamite.” So which one is it, Bonn?

The Dilemma: Gas prices have you seriously considering those high-mileage cars with “D” after their names. So what’s the difference?

People You Can Impress: gearheads, throttle jockeys, grease monkeys, and even tree huggers!

The Quick Trick: The one that smells like rotten eggs is diesel.

The Explanation:
Start with some of the good stuff. The crude oil. The black gold. The Texas . . . well, you get the picture. At the refinery, the crude oil undergoes a process called fractional distillation, which separates the various compounds in the crude oil based on their different boiling points. The first to go are the flammable gases like propane; while bitumen (the goopy stuff used to tar roads) is the last, boiling off at the highest temperature. In between, however, are things like kerosene, butane, diesel, and gasoline (diesel boils off between 250 ̊ and 350 ̊C, gasoline boils around 150 ̊, and kerosene is in between the two).

Gasoline is actually a combination of several products of the refinery. By adjusting the ratios, you get different “grades” of gasoline (regular, super, ultra-high-test, etc.). In fact, one of the numbers you may have noticed on the pump is an “octane rating.” Octane is a hydrocarbon found in gasoline that lowers the tendency to prematurely detonate (we hear it happens to a lot of fuels), known as knocking. In technical terms, an 89-octane gasoline has the knock resistance of a mixture of 89 percent isooctane and 11 percent heptane. The short version: Higher is better.

For decades, lead was added to reduce knocking. But then we figured out that lead is really, really bad for you. Nowadays additives like ethanol have taken its place, which is why you don’t have to make the “regular or unleaded” choice at the pump anymore.

As for diesel fuel, it has plenty of positives and negatives. The fact is it’s almost 20 percent more efficient than gasoline, producing more energy per unit of volume. But it’s also much dirtier, with a higher sulfur content (hence that “diesel smell”), and it can produce soot. Luckily, the diesel used all over Europe is cleaner and ignites better than American diesel, partly from stricter environmental controls. The U.S., however, is following suit and will soon be lowering emissions through ultra-low-sulfur diesel.

In terms of the word itself, diesel comes from the name of the German engineer Rudolf “No Relation to Vin” Diesel. Rudolf invented an internal combustion engine in 1890 that became known as the diesel engine. Whereas in a regular gasoline engine the gas is ignited by the sparks from spark plugs, diesels are compression-ignited engines, meaning that the fuel ignites when mixed with high-temperature, high-pressure air. It’s this rapid intake exhaust of air that gives the diesel its characteristic “chugga-chugga” sound.

The Dilemma: You boned up all night on Miss Cleo and star signs only to find out her passion’s actually astronomy.

People You Can Impress: astrophysicists, astronomers, and Jodie Foster’s character in the movie Contact

The Quick Trick: Pulsars are pulsing stars. Quasars are quasi-stars.

The Explanation:
When a huge star goes supernova, it collapses into a dense, dark neutron star. This thing is pretty odd—a small star that’s about as big across as the length of Manhattan, but more massive than the sun. They’re too massive to be a white dwarf (a threshold of 1.4 times our sun’s mass), but not massive enough to be a black hole.

The pulsar, a rapidly spinning neutron star, was discovered in 1967 by Antony Hewish and Jocelyn Bell. Together the pair detected electromagnetic radiation being “broadcast” at regular intervals, which they believed might have been signals from aliens. Their half-serious theory of “little green men” spurred them to jokingly dub their discovery LGM-1. It now goes by the more appropriately sedate designation PSR 1919 + 21 (that means it’s a pulsar located at right ascension of 19 hours, 19 minutes, and 21 degrees declination. Astronomers, you see, do not like the funny).

Pulsars are so called because they “pulse” with emissions at a steady rate. For example, PSR 1919 + 21 pulses every 1.337 seconds. Of course, there are several varieties, but the most common are rotation powered. These pulsars rotate incredibly fast, throwing off beams of radio waves or X-rays from their magnetic poles. Like a lighthouse, which to a distant observer would appear to “pulse,” pulsars only appear to pulse. We only see the light when the beam points our way.

Quasars also emit radio waves and radiation but are not technically stars. They’re said to be starlike because they emit light. In fact, they are the brightest objects in the universe, more luminous than several thousand galaxies put together. So why aren’t they that bright from where we’re sitting? And more important, how did they go undetected until the 1950s? Well, the answer is that they’re just too old, meaning they were a feature of the earlier universe. Remember, the farther away something is in the universe, the older it is, because the light takes so long to get here. Plus, they’re moving away from us at an amazing clip.

Today eggheads are still arguing about what quasars actually are. Some say they are a type of galaxy formed around a supermassive black hole. Some even believe that our galaxy was once a quasar. If that’s the case, all you parents out there worried that your lil’ galaxy might be a quasar, relax. It’s just a phase.

The Dilemma: At a cocktail party, a nasty brute spills a drink on you. You’d like to compare his manners to that of a more primitive hominid. But which would be more insulting?

People You Can Impress: Anthropologists—they’re just happy to talk to someone who’s not a fossilized skeletal fragment.

The Quick Trick: Neanderthals are more primitive but stronger. Cro-Magnons are us.

The Explanation:
Cognitively speaking, it’s definitely more insulting to call someone a Neanderthal. But if you’re talking musculature, they might just take it as a compliment. Neanderthals (Homo neanderthalensis) were discovered first in Germany’s Neander Valley in 1856. They emerged between 100,000 and 200,000 years ago, give or take, in the early and middle Paleolithic era, and they used tools, albeit very simple ones. Often they resorted to using rocks (or flakes broken off of rocks by hitting them with other rocks), bones, and sticks. And they used fire, too! Neanderthals were more muscular than the later Homo sapiens, and their skulls were flatter, with broad noses and pronounced ridges on the forehead (which is why, to us, they look rather dim). They were also capable of speech, but recent physiological discoveries indicate that their voices were high pitched and nasal, not the baritone grunts we normally associate with cavemen. Despite their similarities to us, they were not—repeat, not—a step on the way to us. They were a dead-end off shoot of an earlier common ancestor, and they eventually lost out to their smarter, more advanced cousins: Cro-Magnons.

As for Cro-Magnons, they’re pretty much just like us. They take their name from a cave in France where Louis Lartet found them in 1868 (well, he found their skeletons. They had died a while before). Unlike Neanderthals, Cro-Magnons are not a separate species from Homo sapiens. In fact, they’re the earliest known European example of our species—living between 35,000 and 10,000 years ago—and are actually modern in every anatomical respect. They did, however, have somewhat broader faces, a bit more muscle, and a slightly larger brain. So how’d they utilize their larger noggins? Cro-Magnon man used tools, spoke and probably sang, made weapons, lived in huts, wove cloth, wore skins, made jewelry, used burial rituals, made cave paintings, and even came up with a calendar. Specimens have since been found outside Europe, including in the Middle East.

Amazingly, the two species actually overlapped in Europe for a few thousand years. So did they interbreed? While scientists allow that there were probably plenty of random matings and hookups, any long-term interbreeding is unlikely. And while there are many reasons for this, the simplest are that a) they were probably physically repulsive to each other, and b) they couldn’t meaningfully communicate. And also c) beer wasn’t invented yet.

The Dilemma: Something from the heavens just crushed your boss, and you’re pretty sure it wasn’t a foul ball.

People You Can Impress: astronomers or just folks wishing on “shooting stars”

The Quick Trick: Oids are outside the atmosphere, ites are inside it, and meteors are in between.

The Explanation:
Say you’re a bit of interplanetary dust or debris trucking through the vacuum of space, minding your own business. You’re not very big. Certainly not big enough to be called an asteroid. In fact, you might just be a speck of dust or even smaller. Congrats! You’re a meteoroid!

But say, for example, a bright blue planet suddenly gets in your way and sucks you in, and before you know it you’re streaking through an atmosphere so fast that you ablate (fancy way to say “vaporize”) and let off a bright streak of light. You are now officially a meteor.

Now, on the other hand, if you started out big enough, then enough of you will emerge from this furnace o’ friction to hit the ground in some farmer’s field, making you a meteorite. Mazel tov! Of course, we should specify here: If you’re made of rock, you’re called a chondrite. Mostly metal? You’re an iron meteorite. A little of both? Say, a rock wrapped in metal? You are hereby dubbed a pallasite.

Believe it or not, about 25 million meteoroids hit Earth’s atmosphere every day. And while most of them burn away to nothing, sometimes the Earth’s orbit will take them through a messy patch of interplanetary junk, like the orbit of a dead comet that’s broken into millions of meteoroids. In such a case, the Earth’s gravity can hoover up these particles by the millions—creating meteor showers. A huge shower emanates from the direction of the constellation Perseus every August, for instance, creating an event that’s widely publicized and not to be missed.

So What’s an Asteroid?
Just as meteoroids are too small to be called asteroids, asteroids are too small to be called planets. Most asteroids that have been discovered (there are now well over 100,000) range from about 10 kilometers to 100 kilometers in diameter and are found in a belt between Mars and Jupiter. In fact, scientists believe that this asteroid belt was a nascent planet that, bullied by Jupiter’s immense gravity, never quite got it together. Asteroids are grouped into a number of families based on their orbits. Those whose orbits cross the Earth’s orbits are called Apollo asteroids. Earth crossing is not a good thing, however. If an asteroid just 1 kilometer across were to hit the Earth, we wouldn’t get a pretty light show. We’d get a jolt equivalent to a 20-megaton nuclear blast, leaving a crater with a diameter equal to the length of Manhattan. That kind of jolt is survivable—if you’re a character in the movie Deep Impact. If you’re a human on earth, it stirs up a bit more trouble.

The Dilemma: Something big and gray just crushed your car and stole your peanuts. So what do you tell the insurance company—African elephant or Asian?

People You Can Impress: ringmasters, Carthaginian generals, and members of the GOP

The Quick Trick: The Asian ones are smaller.

The Explanation:
If you’re thinking about the typical elephant, the one used to represent Republicans in political cartoons (huge, with great big ears and long, curved tusks), the elephant you’re probably picturing is the African elephant, the largest land mammal in the world. More specifically, this most attractive of elephants is the savanna, or bush elephant, one of two separate species in Africa. The other, the forest elephant, can be easily spotted from its larger cousin thanks to its slightly smaller, more rounded ears (the savanna’s are pointier), longer, narrower lower jaw, and straight, pinkish tusks. Oddly enough, from a DNA point of view, the forest elephant is actually more similar to the Asian elephant than to its continental counterparts. Frankly, forest elephants got a little shafted by natural selection—their heads seem too small for their bodies.

Asian elephants, on the other hand, used to be called Indian elephants. That is, until the world realized that the elephant species could be found in other parts of the continent as well. More specifi cally, Indian elephants are one of four Asian subspecies, along with Borneo, Sumatran, and Sri Lankan elephants (Indian elephants are the most widely domesticated and docile—as far as that goes). As for distinguishing features, you can tell an Asian elephant by its smaller size and more rounded back, the single fingerlike extension on its trunk (Africans have two), the two humps on its head, and—if you care to make a very close inspection—19 pairs of ribs, two pairs fewer than African species (though the Sumatran has 20). Also, if you’re a female Asian elephant, no tusks for you.

Ear Conditioning
Believe it or not, an elephant’s ears are pretty effective at cooling the animal down. While elephants can use the great flaps to fan themselves, scientists speculate the cooling mechanism is actually much more sophisticated. Elephant ears are packed with blood vessels, are very thin, and have very little insulating fat. As blood passes through an elephant’s ears, it’s cooled by the air (aided by the fanning of the ears), thereby cooling the entire animal down. So if you think about it, the hotter, drier climate and the larger size of African elephants led them to evolve larger ears.

Good to Know
So which one did Hannibal bring across the Alps to surprise the bejesus out of the Romans? Neither, technically. Hannibal’s pachyderms were believed to be North African elephants, an extinct subspecies of African elephant. As for the word pachyderm, it comes from Greek and means “thick skin.” While most people use this word as a synonym for elephant, hippopotamuses and rhinoceroses can also accurately be called pachyderms.

The Dilemma: You just kissed an amphibian that ribbits. Will it turn into a prince, or will you hallucinate? And do they both taste like chicken?

People You Can Impress: herpetologists, lonely princesses, and Miss Piggy

The Quick Trick: The wartier the skin, the more likely it’s a toad.

The Explanation:
First, let’s discuss how to generally tell the two apart (this isn’t completely foolproof). To begin with, toads’ bodies tend to be shorter and wider while frogs’ are thinner and sleeker. Toads also spend less time in water than frogs, so—side by side—a frog’s feet appear more webbed than its warty cousin’s. Toads also have two bumps on their heads, the parotid glands, which they can use to secrete poison. Frogs, on the other hand, have generally longer legs and are better jumpers. Plus, they tend to be wetter, shinier, and smoother than the dry-skinned toad.

In terms of self-defense, toads (and a few frogs) tend to protect themselves from predators by secreting various toxins from their skins, which in small doses can have interesting results. Ingest the venom of the Bufo alvarius, and you’ll trip out. However, take in the venom of the Amazonian poison dart frog, and you’ll be having a chat with St. Peter in no time.

The one kind of toad that most Americans can name (and giggle when they do) is the erroneously called horny toad. Others (notably those at Texas Christian University, where it’s their mascot) call the animal the horned frog. Strangely enough, both are wrong. The creature is neither a toad nor a frog. In fact, it’s not even an amphibian! It’s a lizard.

Toads Gone Wild
Toads aren’t native to Australia. But Australians sure have more than they know what to do with. So how’d it come to be? The cane toad is the Down Under’s equivalent of kudzu: an introduced species that ran amok. In 1935, 101 cane toads were brought to Australia in the hope of protecting sugarcane from pests. Without any predators, though, the toads went bananas. In fact, today there are so many toads that they’re starting to mess up the whole ecosystem.

How the French Became Frogs
We’d be remiss if we didn’t take this opportunity to explain how the term “frog” became a derogatory nickname for the French. Basically, it boils down to three reasons:

1) Both words start with fr, and that’s just easy;

2) The French eat frogs (particularly their legs) as a delicacy, so “frogs” was probably shortened from “frog-eaters”;

3) Some believe that the fleur-de-lis, the heraldic symbol of France (and of the New Orleans Saints) was derived from three toads on the coat of arms of Clovis, king of the Franks, in the fifth century. At the time, toads were thought to represent Satan, so toads on his coat became a non-non once the good king converted to Christianity. Thus he quickly replaced them with a representation of the lily, now called the fleur-de-lis.

The Dilemma: You’re at a football game and there’s a large, cigar-shaped object hovering suspiciously close to you. Question: Is it a blimp or a zeppelin? And more important, why didn’t you get better seats?

People You Can Impress: whoever’s perched in the nosebleeds next to you

The Quick Trick: When in doubt, just think of Led Zeppelin. Zeppelins are heavy metal—or at least they’ve got metal skeletons. Blimps, on the other hand, aren’t.

The Explanation:
Both blimps and zeppelins work by being lighter than air—they’re filled with a gas that’s lighter than oxygen, so they go up like hot-air balloons. But balloons can’t be steered. Realizing this, German Count (Graf) Ferdinand von Zeppelin decided he wanted to devise a “dirigible [or steerable] balloon” in the 1890s for use in the military reconnaissance work. Eventually, these dirigible balloons took the generic name zeppelin and were used as bombers or scout craft through World War I. This was just one of their many uses, however. The airships doubled as a major mode of transportation between the wars, routinely making transatlantic flights, and the enormous Graf Zeppelin even circumnavigated the globe in 1929.

So just how popular were these zeppelins? Well, enough that the spire on the top of the Empire State Building was designed as a docking mast for them, although that idea proved impractical due to the serious updrafts (and besides, who wants to disembark while dangling 1,300 feet over Manhattan?).

Incidentally, anyone who’s seen the footage of the Hindenburg incinerating at Lakehurst, N.J. in 1937 can see evidence of the main difference between zeppelins and blimps: zeppelins have rigid metal skeletons, making them suitable for longer trips in a wider variety of weather conditions (which also makes them expensive). Blimps, on the other hand, are simply shaped balloons with fins and an engine. Oh, and as for the name “blimp”? It dates back to 1916 and mimics the sound made when the balloon is thumped with a finger.

Led and Other Zeppelins
Led Zeppelin is to date the greatest band ever named after a flying machine (take that, Jefferson Airplane). And while their sound is pretty original, the band’s name is completely attributable to Keith Moon, the late and eccentric drummer of The Who. The pessimistic Moon thought the band, originally called the New Yardbirds, would “go over like a lead zeppelin.” But the plucky young band reveled in the challenge and quickly adopted the name—with a minor change in spelling.

The Dilemma: Your kid and the clone he just created emerge from the basement “lab” looking exactly the same, and now you’re not sure which one to ship off to military school and which one to put up for adoption.

People You Can Impress: anyone who likes puzzles

The Quick Trick: Find out their ages. The clone will be seconds, minutes, days, or years younger. Also, if you’re willing to wait it out, you’ll find clones tend to die faster.

The Explanation:
Clones are basically organisms that have been created from a single individual through asexual reproduction. In the recent past, sheep (like the infamous Dolly), mice, cows, kittens, and dogs have all been cloned, much to the chagrin of ethicists and religious leaders around the globe. In fact, the looming possibility of human cloning has added urgency to their platform.

While the genetic makeup of a clone and its original are almost entirely identical (with less than 1 percent discrepancy between their genetic codes), clones don’t always look exactly like their originals. Cloned dairy cows, for instance, may have spots in different locations and slightly different personalities—perhaps because they come out of separate uterine
environments.

Scientists don’t have a good understanding of why clones tend to age prematurely and die young. Dolly the sheep, for instance, developed arthritis when she was just 2, and died at 6 of a lung disease extremely rare in young sheep, whereas the life expectancy of a sheep is about 12. The problem may be that having an identical genetic makeup doesn’t mean that all those genes will be expressed identically, and clones may not be able to express genes as eff ectively. But all this talk of expressing genes leads us to Express Jeans. . . .

It’s in the Jeans
Anyone who’s purchased jeans in the past decade has no doubt noted the price infl ation. But the world’s most expensive jeans? Those would be the tricked-out blue jeans from APO, which have a diamond-studded main button and rivets of precious metals (somewhere Levi Strauss must be rolling in his grave) and cost $4,000!

Rael Problems in Cloning
The Raelian Movement (which got its start when a guy named Rael Claude Vorilhon self-published a book called The Message Given to Me by Extra-Terrestrials) believes that really smart space aliens created life on earth through genetic engineering. Rael also prophesied way back in the mid-1970s that human cloning would prove to be the key to immortality. Perhaps that’s why a Raelian-funded corporation, Clonaid, announced on December 26, 2002, that a cloned baby had just been born. However, the group has consistently refused to let anyone see this purported “baby,” and pretty much everyone agrees the “cloning” was a hoax. However, the Raelians sue every publication that points out the ridiculousness of their cloning claims, so we’d just like to go on record saying that we’re sure the Raelians probably have cloned a baby and certainly aren’t completely nuts!

The Dilemma: “What just stung me?!”

People You Can Impress: six-year-olds, maybe

The Quick Trick: A bee can generally only sting you once, while hornets and wasps can sting multiple times.

The Explanation:
The problem with elucidating the difference between wasps and hornets is that, at least according to most definitions of wasps, all hornets are wasps. So here’s the deal:

Bees are fuzzy pollen collectors that almost always die shortly after stinging people (because the stinger becomes embedded in the skin, which prevents multiple stings). Bees don’t die each time they sting, though; the primary purpose of the stinger is to sting other bees, which doesn’t result in the loss of the stinger.

Wasps are members of the family Vespidae, which includes yellow jackets and hornets. Wasps generally have two pairs of wings and are definitely not fuzzy. Only the females have stingers, but they can sting people repeatedly.

Hornets are a small subset of wasps not native to North America (the yellow jacket is not truly a hornet). Somewhat fatter around the middle than your average wasp, the European hornet is now widespread on the East Coast of the U.S. Like other wasps, hornets can sting over and over again and can be extremely aggressive.

The Best Darn Animal Roundup Since Noah!
Monarch Butterfly vs. Viceroy Butterfly: Both butterflies have very similar bright orange markings and excrete a bitter acid that makes them taste terrible. But only the monarch flies thousands of miles south in the winter.

Snail vs. Slug: Snails have telltale spiral shells; slugs have shells, too, but they’re invisible because they’re located inside their bodies.

Donkey vs. Mule: A mule is the offspring of a female horse (that is, a mare) and a jackass (that is, either a male donkey or Johnny Knoxville). Mules are sterile and slow, but they’re also strong and hard- working. A donkey is an animal closely related to the horse (obviously, since they can mate), but donkeys are smaller and have longer ears. (See also Eeyore.)

Llama vs. Emu: Both are newly domesticated farm animals, but that’s where the similarity ends: Llamas belong to the camel family, while emus are birds related to ostriches. But the two animals do have one thing in common: crankiness. When llamas get annoyed, which is frequently, they spit up their own stomach acid. And emus are largely solitary animals that don’t like too much human company.

Mighty Mouse vs. Mickey Mouse: Mickey was created in the 1920s by Walt Disney, while Mighty (a Terrytoons character) wasn’t born until 1942. Mickey has no superpowers, while Mighty is excellent at flying and has X-ray vision.

The Dilemma: You just lost your house in a mud slide, and you need to know precisely what to curse. Mainly, because it’s not very dramatic when you raise your fist to the sky and shout, “Darn you, El Niño! Or possibly La Niña!”

People You Can Impress: that gorgeous reporter from the Weather Channel you’ve been secretly stalking for years, from hurricane to typhoon and back again

The Quick Trick: El niño means “little boy”; la niña, “little girl.” Knowing that, all you have to remember is that little boys are much less sugar, spice, and everything nice than little girls.

The Explanation:
Both El Niño and La Niña are abnormal ocean temperatures in the eastern Pacific Ocean, off the coast of South America. El Niños, wherein the ocean temperature rises at least .5 degree Celsius above normal, occur every two to seven years. An El Niño may or may not be followed by a La Niña, which is basically El Niño’s opposite. La Niñas involve colder-than-usual ocean water in the eastern Pacific. An El Niño ended in the spring of 2005; the last significant La Niña was in the fall of 2000.

So who cares if the temperature of the ocean goes up or down a little? Well, most everyone on the planet, as it turns out. The unusually strong tantrums thrown by a one-two El Niño/La Niña punch in 1997 and 1998 alerted the world to the impacts of very slight oceanic temperature changes. El Niño alone is believed responsible for more than 2,000 deaths from flooding, mud slides, and storms. It’s also estimated to have cost $33 billion in property damage—more than Hurricane Ka- trina. While the worst effects were seen in South America, the warm water fed thunderstorms that spread around the world, flooding rivers from Poland to Chile. Much of Indonesia, on the other hand, experienced drought. (El Niño did, however, make for a pleasantly warm winter for those of us living in the northern United States. Ah, silver linings.) La Niña also wreaked havoc on world climate in 1998, but far less dramatically.

Scientists disagree about what causes these weather phenomena. Some say it has to do with increases in the Western trade winds; others believe the water temperature heats up for several years near the equator before it spreads out to sea.

Too Much Pressure: Low vs. High Pressure Systems
So what are TV meteorologists talking about when they vaguely wave their hand over a huge swathe of the map and insist that there’s a “low” or “high” pressure system in the area? Basically, low pressure systems—i.e., areas of unusually low air pressure— are associated with precipitation (including everything from rain showers to category 5 hurricanes). The lower the air pressure, generally, the stronger the storm. High pressure systems, meanwhile, usually portend sunny skies and cooler temperatures. This is why winter days tend to be colder when it’s sunny (high pressure) rather than cloudy (lower pressure).

The Dilemma: What Just Happened?!?!?!?!?!?!?!?!

People You Can Impress: fellow survivors

The Quick Trick: If you’re standing in an absolute wasteland amid thousands of corpses, it was a nuclear bomb. If you’re standing in a normal city street amid a moderate amount of inconvenience, it was a dirty nuclear bomb.

The Explanation:
Here is the primary difference: Nuclear bombs have, in the past 50 years, killed hundreds of thousands of people. Dirty nuclear bombs have, in all of human history, killed exactly no one—partly because they aren’t terribly dangerous and partly because not one has ever been detonated.

Conventional nuclear weapons get their explosive power from either nuclear fission or fusion. The bombs dropped on Hiroshima and Nagasaki—the only nuclear weapons that have been used in warfare—were both fission bombs. Fusion bombs, sometimes called hydrogen bombs, are even more powerful—the U.S. once detonated a 15-megaton fusion bomb in a test. That’s approximately 100 times more powerful than “Little Boy,” the nuclear weapon dropped on Hiroshima that instantly killed 100,000 people. Most modern bombs combine fission and fusion: a small fission bomb s used to create heat adequate to fuel the
fusion.

Even with the physics know-how, the bombs require exceedingly rare isotopes of either plutonium or uranium. The process of getting the elements to the necessary isotope is known as enrichment, and enrichment is generally the stumbling block for nations looking to join the nuclear club. It was even a challenge for the U.S.: Almost 90 percent of the Manhattan Project’s budget was spent enriching uranium.

In short, nuclear weapons are extremely difficult to make—and we hope they always will be. A dirty nuclear bomb, on the other hand, could be made by a reasonably smart 14-year-old with access to hospital equipment. Dirty bombs combine conventional explosives (say, dynamite) with radioactive materials (say, cesium, which is used in radiation treatment for cancer patients). Almost all scientists believe that even in the case of a well-designed dirty bomb, the explosive would cause much more damage than the radiation. The fact is there just aren’t any acquirable materials radioactive enough to cause much fallout. And while it could be very expensive and inconvenient to clean up an urban area after a dirty bomb attack—that’s about it. In short, the difference between the two is that conventional nuclear weapons are infinitely more worrisome.

“Dirty” Little Secrets
The only recorded attempt to detonate a dirty bomb came in 1995, when Chechen rebels—who had been on the forefront of terrorism techniques since the Soviet Union’s breakup—called reporters to say they’d planted a bomb in a Moscow park. Made of dynamite and cesium taken from a cancer treatment center, the dynamite might have killed people, but its cesium would have been just the equivalent of a few X rays for those walking past the park. Regardless, the bomb was defused before it exploded.

The Dilemma: Having just finished a six-pack of Mountain Dew, a Pixy Stick the size of a walking cane, and a state fair’s worth of cotton candy, you can feel your teeth vibrating. Also, you’re vaguely worried you might be at risk for some type of diabetes—but which one?

People You Can Impress: fifth-graders who snort Fun Dip on double-dog dares

The Quick Trick: You may know Type 1 as “juvenile diabetes.” If the body is producing any insulin, it’s Type 2.

The Explanation:
Technically known as diabetes mellitus, diabetes is marked by persistent or recurring elevated levels of blood sugar. Although it can be treated with changes in diet, exercise, and the injection of insulin (more on that in a moment), diabetes is not curable. And untreated it has the potential to escalate pretty quickly. Diabetes can lead to coma, heart disease, kidney failure, blindness, amputation, and even impotence.

Type 1 diabetes has been recognized since time immemorial. Usually beginning in childhood or adolescence, a misfiring autoimmune response within the body starts destroying the pancreatic cells that create insulin, the hormone that removes glucose from the blood. Without insulin, the body suffers twofold: High blood sugar causes damage to the eyes, heart, and other organs, and poor protein synthesis leads to a general weakening of the body. In short, without insulin, you die—which is precisely what happened to all Type 1 diabetics until 1922, when two scientists, Sir Frederick Grant Banting and Charles Best, discovered insulin and its significance. And while Banting and Best could have gotten fabulously rich by patenting their discovery, they chose not to, so that relatively inexpensive insulin therapy could be immediately available worldwide. How wonderfully, amazingly Canadian of them. Ever since, Type 1 diabetes has become a chronic but not necessarily fatal disease—and while it’s no fun injecting yourself with insulin every day, it sure beats dying in your teens.

As for Type 2 diabetes, no one knew it existed until 1935, when physician Harry Himsworth identified it. Today approximately 95 percent of diabetes cases in America are Type 2. Sometimes called slow-onset diabetes, Type 2 generally appears over the course of several years. Here the body produces insulin, but cells don’t respond to it correctly. The first treatment for Type 2 diabetes is almost always a change in diet, exercise habits, and weight loss. Type 2 diabetes disproportionately affects the sedentary, obese, and elderly. And while it, too, is incurable, it can usually be controlled without insulin therapy.

All in all, you’d rather have Type 2. Type 1 diabetes decreases life expectancy by an average of 15 years, while the average Type 2 diabetic only lives 5 to 10 fewer years than a typical nondiabetic. That said, many diabetics of both types lead long and healthy lives—and Type 1ers owe it all to those selfless Canadians.

The Dilemma: You know they’re both very important, albeit completely imaginary, lines. But that’s about all you’ve got.

People You Can Impress: astrologers

The Quick Trick: The Tropic of Cancer is located above the equator; Capricorn, below it.

The Explanation:
There are five major latitudinal circles on earth, and we like to think of them in a clothing metaphor: The Equator, located at 0 degrees latitude, is the earth’s belt. The Tropic of Cancer, located at 23 degrees, 26 minutes, 22 seconds north of the Equator, is sort of the Earth’s bra. (The Earth, for the purposes of this metaphor, is a lady.) The Tropic of Capricorn, founds 23 degrees, 26 minutes, 22 seconds south of the equator, is the Earth’s garter belt. Th e Arctic Circle (66 ̊33′38″N) is the Earth’s choker necklace, while the Earth’s socks rise to the Antarctic Circle (66 ̊33′38″S).

We know what you’re wondering (aside from why the Earth is apparently not wearing a blouse): How do we know the as- trological sign of imaginary lines? Did we get drunk at a bar and sidle up to them and just ask? No. The Tropics of Cancer and Capricorn mark the northernmost and southernmost points on the Earth where the sun can be seen directly above (in summer for Cancer and winter for Capricorn). When the latitudinal lines were named hundreds of years ago, the sun was entering the constellations of Cancer and Capricorn during the summer and winter solstices, respectively. But because stars change position relative to the sun over time, the sun is now in Sagittarius during the winter solstice and Taurus during the summer solstice. In short, the Tropics are due for a renaming—but tradition will probably hold; otherwise we might have to rename the Henry Miller novels (see below).

Tropic of Cancer vs. Tropic of Capricorn: The Literary Edition
Published in 1934 and 1939, respectively, Henry Miller’s erotic novels Tropic of Cancer and Tropic of Capricorn caused quite a scandal. The publisher of a pirated edition of Cancer was imprisoned for 10 years, and both novels were banned for decades in the United States until the Supreme Court affirmed their literary value in 1964. The difference between the two? Both are very, very dirty and star a guy named “Henry Miller,” but Capricorn is set in New York, while Cancer takes place in Miller’s adopted hometown, Paris. Also, only Cancer was once featured in an episode of Seinfeld. (It’s the one where Jerry gets a notice from the library that he’s had the book checked out since 1971.)

The Dilemma: You’ve recently been diagnosed with ADHD and are wondering whether or not your doctor has prescribed you crank to treat your hyperactivity. Because while you’re not an MD or anything, that seems like a bad idea.

People You Can Impress: This is the rare bit of knowledge you can use to impress both chemists and drug addicts.

The Quick Trick: If you’re taking diet pills, that’s amphetamine. If you’re smoking crystal, that’s methamphetamine (and also not so good for you).

The Explanation:
The difference here, we regret to report, involves some polysyllabic chemistry, but on the up side, the periodic table need not be mentioned. Both drugs are stimulants of the central nervous system, just like MDMA, commonly known as Ecstasy. But amphetamine is known technically as methylated phenylethylamine, while methamphetamine is known as double methylated phenylethylamine. The second methylation (to make up a word) changes the compound’s interaction with the body.

Regular amphetamine can be plenty bad for you. Speed is found in everything from the ADHD drug Adderall to diet pills. Many nations, including the U.S., also sometimes give amphetamines to members of the armed forces to increase alertness. But it comes with more than a couple problems: First, it’s addictive. Second, it can cause heart attacks. Third, it can cause “amphetamine psychosis,” which is very similar to schizophrenia except you have more energy. But such side effects are rarely a problem for those who take amphetamines as prescribed.

Methamphetamine, on the other hand, is widely considered too dangerous to be prescribed. Somewhat stronger than an amphetamine, meth was first synthesized by a Japanese scientist in 1919. Widely prescribed in America and abroad in the 1950s, meth was used to treat everything from alcoholism (ironic because, at best, it only caused a switch in addictions) to Parkinson’s (ironic because meth causes involuntary body tics). The production of meth, which involves mixing over-the-counter cold medication with hydriodic acid, wasn’t even illegal in much of the U.S. until 1986.

Long known as a drug abused mostly by truckers and bikers, meth only spread into the larger population in the 1980s. But by the year 2000, 4 percent of Americans polled acknowledged having used meth at least once. The allure of meth is that it’s very cheap and makes you very high—the drug gives you a feeling of ecstasy caused by dopamine flooding the central nervous syndrome. Unfortunately, this eventually leads to irreversible brain damage.

But that’s not all. Chronic abuse is associated with paranoia, hallucinations, strokes, and dementia. Also, it is exceptionally bad for your breath. And it’s no fun to get off the stuff : Withdrawal symptoms include seizures.

The Dilemma: A fearsome creature that could split your body in two with a few well-aimed swats is standing before you on its hind legs. You, curious intellect that you are, can’t help but wonder about this creature’s species.

People You Can Impress: everybody—if you survive

The Quick Trick: Grizzlies are brown; black bears are (get this) also sometimes brown—so that may not help. A quick way of telling the difference between the two is: If the bear in question just gored you to death, there’s at least a 70 percent chance it was a grizzly.

The Explanation:
Both bear varieties get a bad rap. In the past 100 years, only about 35 black bear–related fatalities have been reported in North America. The purportedly terrifying grizzly, by comparison, has been responsible for perhaps 100 deaths in the past century. The lowly mosquito, meanwhile, kills about 2 million people a year. But while neither bear is much of a man eater, you’re significantly better off running into a black bear than a grizzly. Sure, black bears are adept tree climbers, which cuts off a potential escape route. But they’re relatively small—adults usually weigh between 150 and 350 pounds. And they’re pretty relaxed. Many black bears are so tame that they’ll eat food from your hand (although we advise against trying it, because it 1) is illegal, 2) can cause dependence on human food, which is bad for the bears, and 3) also potentially is bad for your hand).

Grizzly bears, meanwhile, don’t have such a laid-back reputation. Also known as bruins and brown bears, grizzlies can weigh 1,400 pounds, stand 13 feet tall, run 35 miles per hour, and kill you with a single swat of the paw. While black bears are found throughout North America, grizzlies now live primarily in Alaska and Canada’s Yukon Territory. (Both the UCLA Bruins and the Cal–Berkeley Golden Bears have a grizzly mascot, but the bear hasn’t been seen in California since 1922.) Grizzlies prefer vegetables to meat, but sustaining 1,400 pounds on a diet of berries ain’t easy. To compensate, their favorite protein-rich food is the moth. If you think you’re scared of bears, imagine the plight of the Alaskan moth: Grizzlies can wolf down as many as 40,000 of them in a single day.

The Grizzly Question
So black and brown bears differ in size, temperament, and habitat. But none of this addresses the real question: Is Yogi Bear a black bear or a grizzly? The most famous resident of Jellystone Park is brown—but, as noted, so are many black bears. Both bears will scavenge for food, leaving pic-a-nic baskets in danger. But since Yogi stood on two legs and is, after all, smarter than the average bear—we feel he is indisputably a grizzly. Grizzlies stand on their hind legs much more often than black bears and also have bigger brains.

The Dilemma: You’ve accepted the fact that there’s a quartet of high-kicking mutant turtles terrorizing the local sewer system. The real question is: Are these hard-shelled hooligans a bunch of samurai or ninja?

People You Can Impress: If you manage to parlay this information into becoming either a ninja or a samurai, you’ll impress most everybody.

The Quick Trick: Samurai wore elaborate armor and never stabbed anybody in the back; ninjas wore no armor and loved stabbing people in the back.

The Explanation:
The word samurai is somewhat analogous to European knight: They were considered nobility, worked for noble higher-ups, and were renowned for their great bravery and code of honor. So much so that all the little kids wanted to grow up to be samurai! (Or so we imagine.) Ninja, on the other hand, were well-disguised mercenary assassins governed by no code save secrecy.

The samurai arose in the 10th century, working as a kind of police force for the Japanese city of Kyoto. By the 12th century, the samurai life as we know it today was established; samurai were well-educated men who could read, write, and kill thanks to their extensive martial arts training. They also adhered to the Bushido, an orally transmitted ethical code that forbade samurai from striking enemies from behind or pillaging unnecessarily. It also required them to commit ritual suicide, known as Seppuku, if they dishonored themselves or the samurai tradition.

At the peak of the tradition, between 7 and 10 percent of the Japanese population—most of Japan’s army—were considered samurai. And although samurai are usually depicted with swords, they did adapt to modern warfare with firearms in the late 16th century. In fact, samurai helped Japan to win wars against Korea, China, and even Spain, staying on the scene until the end of the 19th century.

If the samurai relied upon a code of honor, the ninja relied upon their stealth and ferocity. Technically, a ninja is anyone who practices the Japanese martial art ninjutsu (meaning that you, too, can become a ninja just by visiting your local neighborhood dojo!). Because ninjutsu teaches everything from stick fighting and knife throwing to disguising yourself and predicting the weather, figures like the 16th-century Shogun Tokugawa Ieyasu have employed ninja tactics to escape enemies early in their political careers. But almost from the beginning, the myth of the ninja proved even more compelling than the reality of them. Long before their portrayal in movies, ninjas were romanticized by everyday Japanese citizens, who shared stories of the ninjas flying, or making themselves invisible. The real ninjas, meanwhile, were mostly schlepping about, spying and assassinating, just trying to pay the bills.

The Dilemma: Bless me, Father, but I can’t tell you guys apart.

People You Can Impress: Gregorian chant fans

The Quick Trick: Franciscans’ robes are gray or brown, Dominicans’ are white with black cloaks, Benedictines’ are usually black but sometimes white.

The Explanation:
Benedictines, oldest of all Catholic monastic orders, follow the order of St. Benedict of Nursia. Writing their Rule in the sixth century, Benedict’s precepts had three guidelines: community stability, conversion of manner, and obedience. Further, the abbot of the monastery was considered the father (that’s what “abbot” means) and the monks his family. The truth is, any stability to be found in Europe during the Dark Ages came from the Benedictines. But corruption within the order led to a wide-ranging reform in the tenth century centered at the Abbey of Cluny, which brought new organization and vigor. On a slightly different note, the Trappists, who in Belgium make Chimay beer and in Kentucky make cheese, are actually another Benedictine off shoot.

As for the Franciscans, they’re a mendicant (“begging”) order founded, as you might expect, by St. Francis of Assisi (1181–1226), the patron saint of animals. Francis took Christ’s call to go forth without shoes or staff or money as a literal command, and founded his Ordo Fratrum Minorum (Order of the Friars Minor, or, more literally, “Order of the Little Brothers”) in 1209. Best known for their plain robes (they’re still called the Greyfriars in some places), they traveled the countryside singing and preaching. Overall, the Rule of St. Francis was simple, based on a vow of poverty. But it wasn’t all happy begging and singing. The friars felt the best way to get closer to God was hard work. To this day, some Franciscan friars still wear the traditional hooded woolen robes, rope belts, and sandals. Notable Franciscans include St. Bonaventure, William of Occam (namesake of “Occam’s Razor”), and the fictional Friar Tuck. As for Francis himself, he was believed to have miraculously borne the stigmata (the nail and spear wounds of Christ) late in his life.

St. Dominic de Guzmán founded his order around the same time as St. Francis, and he had one main purpose in mind: preaching (their official name is Ordo Praedicatorum, the Order of Preachers). The Dominicans arose at a time when heresies were rife in parts of Europe, and Dominic wanted to return heretics to the fold. Like the Franciscans, the Dominicans were mendicant friars, and they had their own set of precepts: poverty, chastity, and obedience. Despite their godly mission, or perhaps because of it, the Dominicans were the driving force behind the Inquisition. In fact, St. Thomas Aquinas was a Dominican, as was the terrifying Grand Iquisitor, Torquemada.

The Dilemma: Despite hearing news about the Mid- dle East every day, you still don’t know Shia from shinola.

People You Can Impress: Iranians, Iraqis, Syrians, Jordanians, and TV talking heads

The Quick Trick: The Shia believe that the early succession of power should have gone like the name of a very famous boxer: 1) Muhammad, 2) Ali.

The Explanation:
Like Christianity, Islam is home to a spectrum of sects espousing different beliefs and practices. And just as Christianity can be divided into two large groups—Catholic and Protestant—from which other subsects have emerged, so too with Islam: Shia and Sunni.

Unlike Christianity, whose major split wouldn’t occur for nearly sixteen centuries, Islam split almost immediately after the death of its founder, the Prophet Muhammad (circa 570–632 ce). The rift stems from a disagreement among Muslims over who was the rightful successor to Muhammad.

After the prophet’s death on June 8, 632, a gathering of his followers met at Medina and proclaimed Abu Bakr (kinsman, companion, and early convert of Muhammad) caliph, or political leader. The claim stemmed from his close relationship with Muhammad, and the fact that Muhammad had asked Abu Bakr to lead prayers when too ill to do so himself. Those who recognize Abu Bakr and his three immediate successors, called the Four Rightly Guided Caliphs, are referred to as Sunni Muslims, and today almost 90 percent of Muslims worldwide fall into this category.

One group of followers, however, refused to accept Abu Bakr. These Rafidi (“Refusers”) supported the claim of Ali ibn Abi Talib, Muhammad’s cousin (and son-in-law). The claim is based on a sermon the Prophet had given at Ghadir Khum, in which Muhammad referred to Ali as mawla, which some translate as “master.” Ali’s supporters called themselves Shiat Ali (the Party of Ali), though today they are known as simply Shia. Ali did eventually ascend as the fourth caliph. To Sunni, he is the last of the Four Rightly Guided Caliphs. But to Shias, he is the first caliph and, more important, the first Imam—a word Shia Muslims use to refer to the person chosen leader of all the faithful. While they and the Sunnis both revere the Koran, they accept different hadiths (oral traditions), so their laws are different. Many Shias, for example, allow temporary marriage. Shias also recognize esteemed imams as supreme experts on Islamic law, called Ayatollahs or, for the really big guys, Grand Ayatollahs. As for the locations where Shias have a significant Muslim majority, there are really only two: Iraq and Iran.

Much is made of the differences between Shias and Sunnis, but almost all the violence between them in the past 50 years has been caused, directly or indirectly, by Saddam Hussein—a nominal Sunni who by his own admission was never religious.