10 Scientific Distinctions It's Fun to Argue About [Daily 10]

10 Scientific Distinctions It's Fun to Argue About [Daily 10]:
Everybody loves to argue, especially on the internet. And science is full of seemingly small, but vitally important, distinctions that can spawn a hundred fascinating debates. Plus there are a lot of scientific distinctions that get misunderstood by popular culture — or are too fine to make it into popular use at all.
Here are 10 seemingly minor scientific distinctions that it's worthwhile (and enjoyable) to get pedantic about.
Top image: Debbie Aird Photography/Shutterstock.com
10. Fruits and Vegetables
Generally, when I mention tomatoes as part of a list of vegetables, and people tell me that the tomato is actually a fruit, I smile wide, thank them for their input, and then count down to the day when I can serve them pasta with marmalade and oregano. And yet, they're technically right.
Anything that contains a fertilized seed meant to carry on the genes of the plant — basically, an ovary — is a fruit. That includes tomatoes, berries, pineapples, grains (including corn) and nuts. We tend to be attracted to fruits because they often get a head-start in edibility. Plants disseminate their seeds by feeding their fruits to the right animals, and human botanists take over and make everything sweeter. Everything else on a plant is the stuff it does not want you to eat, including the leaves, and roots, and stem. These things are the vegetables, and we tend to want to eat them less, too.
9. Kangaroos and Wallabies
This is one of those questions that always bothered me just enough to make me pause while I thought about either kangaroos or wallabies, but never enough to actually look them up. I suspect many people are in my position, hence the ongoing mini-snafus about the terms.
The main question you should ask yourself when approaching an unknown hopping marsupial is this: Can it kick me to death? If it can, it's probably a kangaroo (or you've put yourself in a very weak defensive position). Wallabies are between four and fifty pounds and get about two feet tall. Kangaroos can get eight feet tall, weight two hundred pounds, and can gut people with a kick. Wallabies are also a few shades lighter than kangaroos.
Since there are some small kangaroos, though, the best way to tell is by opening up the thing's mouth and hoping that it's a wallaby. Wallabies pluck leaves, and use their teeth for grinding. The result is flat teeth on a flat surface. Kangaroos, on the other hand, eat grasses that they have to saw through with their teeth. They have a rounded jaw, like a knife blade, with teeth that have a groove in the middle and a point on each side. What I'm saying is, if you have to fight something — pick a wallaby. (It's weird, though, that Australians seem to pick just the opposite.)
8. Low Earth Orbit and Medium Earth Orbit
Look, there are only so many ways that things can whiz around the Earth. In fact, it seems there should only be one way that things whiz around the Earth. But there are several, and it's easy to get confused between them. The lowest is Low Earth Orbit. LEO extends from 200 to 2,000 kilometers up. Low Earth Orbit is about the closest anything can whiz around the Earth without banging straight into it. In other words, below that, you're either falling or flying (I would suggest you pick flying). The International Space Station, about 350 kilometers from the surface, is in LEO. Stuff here goes around relatively quickly, and so the ISS orbits the Earth about 17 times a day.
Medium Earth Orbit gets its own designation because it's the orbit that requires battle gear. From about 2,000 to 36,000 kilometers Earth's radiation belts will take out electrical equipment. Anything that beeps up there needs specially-made shielding.
7. Geostationary Orbit and Geosynchronous Orbit
There's nothing like words that share the first and the last two syllables to really get people mixed up. Especially when they sound like they do the exact same thing. Both sound like they maintain a constant position over one part of the Earth. And they kind of do, in different ways.
Geostationary Orbit is a satellite parked at a certain latitude, and traveling with the Earth at whatever speed the ground is turning at that latitude. It's called stationary because if you stayed on one spot beneath it on the Earth a looked up (through an incredible telescope) you would always see it above you.
Geosynchronous Orbit is a little more complex — for the satellite, at least. It makes one turn, with the Earth, every day. It does that while wandering anywhere, from pole to pole, but always on the same line of longitude. Technically, one Geosynchronous Orbit contains every possible Geostationary Orbit. Both are held at about 36,000 kilometers above the surface of the Earth.
6. Air and Space
Space is a good thing to be pedantic about, because no one really agrees where it begins — so you can really roll up your sleeves and argue. Originally, in the 1950s, the World Air Sports Federation wanted to declare a line that denoted where space began. A group, led by Theodore Von Karman, declared 100 kilometers up and above 'space,' because it was a big, round number that seemed pretty high up before the days when we were launching things tens of thousands of kilometers into orbit. The 100 kilometer mark was callled The Karman Line.
Pretty soon, though, it became apparent to all that 'Well, it looks good in base ten,' was not a suitable choice for figuring out whether you were still on Earth or not. The US Space Agency gives astronaut wings to anyone who gets over 80 kilometers up, presumably to keep ambitious folks from opening the hatch of their craft and trying to jump for it. At 118 kilometers, ions start behaving the way they do in space, rather than the way they do on Earth, zooming around at 1000 kilometers per hour. At about 350 kilometers is the International Space Station, and that has 'space' in the title. They wouldn't fool us about that, would they? But if you want to be absolutely, positively sure you haven't wasted a trip, get above 600 kilometers. That's where the last of our atmosphere runs out, and you're in space proper.
5. Nuclear and Thermonuclear Weapons
As stated before in the kangaroos vs wallabies entry, I'm always interested to know what, precisely, is killing me. And there's never enough time to look things up while it's happening. So it's best to know in advance.
A nuclear bomb is a bomb that sends neutrons careening into heavy elements, causing them to split, releasing more neutrons and splitting more heavy elements, and unleashing a huge amount of energy. Thermonuclear bombs are a little bit different. A thermonuclear bomb uses a regular atomic bomb, with heavy elements, to generate an enormous amount of heat. That heat fuses together hydrogen atoms, making larger nuclei instead of smaller ones, and releasing even more energy. Thermonuclear bombs are also called hydrogen bombs.
4. Livings Things and Nonliving Things and Viruses
This is another one of those horrible fights that never stops. We know what's alive by the way it grows, respirates, moves, reproduces, and adapts to its environment. We know what's nonliving because it doesn't do any of those things. Viruses live in the constantly-fought-over territory in between. When they were first isolated by Wendell M Stanley in 1935, he noticed they had none of the ability to perform necessary biological functions and considered biochemicals. Stanley won the Nobel Prize for his discovery — but even the prize itself was indicative of the lack of life in a virus. It was the prize for chemistry. Virus were just a bunch of nucleic acids in a coating. On the other hand, they most certainly adapt, they find a way to perpetuate their genes. They just can't do it by themselves. I guess the question is — is a completely dependent and parasitic existence really a living existence? (Shall we consult a lawyer?)
3. Left and Right
This is a good one. What is it, people? What is it? There are left-handed and right-handed people. The body is not entirely symmetrical. There has to be a difference, even if it's only in our perception, but try to define it and you end doing laps in your mind, like a dog chasing its tail. In the end, the only way to define left and right is by using another arbitrary set of directions. Left is the part of you that's on the west side when you're facing north. Right is on the east side when you're facing north. Once we get off planet, we're going to have to figure out a new definition for this.

2. Planets and Planetoids
The Pluto planet controversy rages on. I, for one, like the fact that Pluto isn't a planet. Pluto was the god of death and the dead. Do we want a big ball of death around us? No. We want to de-emphasize that as much as possible. But the real reason Pluto isn't a planet is because it's easier that way. No, really, it is.
Pluto was originally discovered in 1930, and it looked pretty planet-like and solitary. Sure, it had a weird orbit that crossed the orbit of Neptune and was at an angle to the orbits of the other planets. But what did that matter? It was a big hunk of rock orbiting the sun. Close enough, right? Later we found out it wasn't alone. It was orbiting the sun with a bunch of buddies, including one, Eris, that was larger than Pluto. (Eris, by the way, was the goddess of strife, another one we don't really want hanging around.) So now we either had a bunch of objects that all needed names and memorization by school children, or we had eight planets. We chose the eight planets. And that became the definition of a planet, rather than an asteroid or dwarf planet or whatever else: large objects, orbiting in parallel orbits around the central star. Any of their moons should be a good deal smaller than them, and most importantly — there should be few enough of them that we can easily name them. Too many more, and we'll just give them numbers.
1. Apes and Monkeys
There are many differences between monkeys and apes. The primary one is that 'monkey' is a funny word. Say this with me; "Monkeymonkeymonkeymonkeymonkey." Funny, right? "Apeapeapeapeape," - no. It's just not as good. Which is why many people say "monkey," when they actually mean ape.
But when you're being wrong, it's important to know how and why. Apes are generally bigger, but there are some apes that are smaller than monkeys. Apes never have tails, but some monkeys are missing theirs, as well. In the end, the best way to tell the difference between an ape and a monkey is to consider whether its frame looks like a human's frame or looks like a cat's frame. Cats can get up on their hind legs, but humans are comfortable there. Humans and apes can swing on the paradoxically-named 'monkey bars.' Monkeys (and probably cats) have shoulders that give them problems with swinging from overhead branch to overhead branch, and would prefer to run along them. If nothing else, you can memorize; gorillas, chimpanzees, orangutans, and bonobos are apes. Lesser apes are gibbons and siamangs. Anything else, and you are in monkey territory. Get outta there! (I hate monkeys. But it's still a funny word to say.)
Hands Image: Krzysztof P. Jasiutowicz
Kangaroo Image: Fir0002/Flagstaffotos
Satellite Image: NASA
Bikini Atoll Nuclear Test Image: Department of Energy
Pluto-like Planet: NASA
Via How Stuff Works twice, National Zoo, The Straight Dope, Caltech, ABC, Slate, Wisegeek twice, Dictionary.com, and Scientific American.