moth & butterfly
In general, butterflies have slender antennae that are club-shaped at the ends, while moths have shorter, more feathery antennae. That’s the biggest difference. Also, butterflies tend to be more brightly colored and more active during the day, whereas moths are more likely to be dull-colored and nocturnal, although those distinctions aren’t universal. Both belong to the order Lepidoptera.
theorem & theory & law
Theorem is a mathematical term. It is a statement, such as the Pythagorean Theorem (a² + b² = c²), that has been proven, derived from other statements and/or axioms.
Theory is a scientific term. It is a framework, such as the theory of evolution, for explaining and understanding a vast quantity of observed data. Any good scientific theory will make consistent, objectively verifiable predictions.
Scientific laws are distinct from scientific theories. A law merely describes how the universe works, and makes predictions; a theory explains why things are the way they are. Newton’s laws of gravity tell us what gravity does, what we can expect to see in our experiments. Einstein’s theory of relativity not only makes more precise predictions, it also gives us a clearer framework for understanding how gravity operates in a broader sense: It is a warping of spacetime caused by mass. (Of course, much more explanation is still needed.)
In common (i.e., nonscientific) usage, a theory is sort of a hunch, an idea that might or might not be true, while a law is much more certain. This can lead to confusion when non-scientists talk about science. People may wrongly believe that the big bang theory or the theory of evolution are less certain than the laws of gravity. In fact, scientific laws and theories are both about as ironclad as we can get in this imperfect world. What a non-scientist might call a “theory,” a scientist would more likely call a hypothesis.
judge & justice
I’ll stick to the US legal system here.
We’ve all heard about Supreme Court justices, as opposed to judges on other courts. But what’s the distinction? Is it only the Supreme Court that has justices? Is it about federal- vs. state-level courts? Or maybe it’s about trial vs. appellate courts? It was surprisingly hard to find a clear, authoritative answer to this question. But I think I’ve got it figured out.
A judge presides over a court — any court. A justice is a judge who presides over any supreme court, whether it’s the US Supreme Court or a state supreme court. So, as near as I can tell, the distinction is solely based on supreme courts vs. other (non-final) courts.
If anyone has more expertise with US law than I do (and it doesn’t take much), feel free to chime in.
lawyer & attorney
Again, I’ll stick to American English here. In the US, there is essentially no difference between a lawyer and an attorney.
A lawyer is someone who practices (or has studied) law. Broadly speaking, an attorney is someone who acts as an agent for another; but in modern usage, attorney is nearly always short for attorney at law, that is, someone who represents another in legal matters.
So you could make the case that one must actually represent a client to be an attorney, whereas a lawyer need only understand the law. Other, contradictory distinctions have been proposed as well (e.g., lawyers are those who have graduated law school, while attorneys are those who have passed the bar exam). In practice, however, such distinctions are rarely observed, even by lawyers (or attorneys) themselves. It’s safe to treat these two words as synonyms.
genie & djinn
We’ve all heard about genies: They live in lamps and they grant three wishes each, at least according to Disney’s Aladdin. But you may also have heard of djinn: Powerful beings in Middle Eastern mythology (and in Islamic belief). The names and meanings are vaguely similar. Are they the same thing? What’s the deal?
We’ll start with genie. Originally, a genie was a sort of guardian spirit who kept watch over a person or a place. The name derives from the Latin genius, which meant something similar (before it came to mean “a really smart person”). Genie was a Western European concept that had little to do with lamps, wish-granting, or Arabian deserts.
Meanwhile, djinn (or jinn, depending on your preferred transliteration) is an Arabic term. In Islam, the djinn are specifically mentioned in the Quran as one of the three classes of intelligent beings created by God, the other two being humans and angels. Whereas angels were created from light and have no free will, doing only the will of God, the djinn were created from “smokeless fire” and, like humans, do have free will. Thus, they are powerful beings that can act for good or for evil.
Two separate concepts. So what’s the connection?
Well, djinn also show up in Middle Eastern folklore, and in particular, in various places in the Arabian Nights. When the West grew interested in the Nights, one early translator decided to translate djinn as genie, due to the similar-sounding name and vaguely similar meaning. Ever since, the Middle Eastern meaning (or at least our Westernized version of it) has displaced the original meaning of genie, which has been largely forgotten.
Burma & Myanmar
These are two different names for the same country in Southeast Asia. Burma is the traditional name. Myanmar is the “official” name preferred by the government (which is largely military-run and not overly enamored with human rights). The US and many others — both inside and outside the nation itself — are not overly enamored with the military-run government, and still prefer Burma.
I have a whole list of these “What’s the difference between … ?” pairs and triplets, and I’m researching them as I go. Sometimes I know the answers in advance, but often I don’t, and sometimes (as with theory vs. law) it turns out that I was wrong about what I thought I knew.
In other words, I’m having fun.
What say you, readers? Up for round 3?