Chad at Uncertain Principles raises the issue of unfortunate names in physics and astronomy. I agree that “strange” and “charm” and “bra” and “ket” are on the cutesy side, but astronomical nomenclature has got to be worse. A fair bit of it is just awkward (for example, in a young star formation region, you’ll often find both molecular hydrogen, which is H2, and ionized hydrogen which is also known as “H-two”, i.e. “HII”, where the II is the roman numeral two). Other terms are historical anachronisms (“planetary nebulae” have nothing to do with planets, but they looked sort of like them through the earliest telescopes). However, to the astronomer teaching large introductory courses (which is most of us), astronomical lingo is downright perilous.
Case in point: The spheroidal distribution of stars in the centers of rotating disk galaxies is called the “bulge”. Now, introduce a bunch of bored and horny 19 year olds into the mix, and you have a dangerous cocktail. One of my colleagues lost complete control of a 250 person lecture class when she had two male students hold up pictures of different galaxies, while she expounded on how “This guy over here has a small bulge, but the bulge of this guy is quite prominent.” The titters started as she forged ahead unknowing, until the entire class collapsed in hysterics. At that point, you just have to put down your laser pointer, send the class home, and head for the bar. Learning is over.
While not quite as extreme, I’ve always been fond of “violent relaxation“, originally coined by Donald Lynden-Bell . The relaxation bit refers to a gravitationally bound system (like a galaxy) coming to its final equilibrium state, and the violent part refers to the fact that this process is not slow and steady, but is usually characterized by rapid changes in the gravitational potential. Broken down like that, it’s not as nuts as you’d initially think, but it’s never going to sound PG.
March 7th, 2007 at 2:24 pm
Hee hee…a similar thing happened to me a couple weeks ago, when, teaching about fluid mechanics and the Bernoulli equation, I declared that the “fluid flow rate depends on the total head” in the system. I turned bright red…
March 7th, 2007 at 2:24 pm
Along the same line, never mention the name of the 21st moon of Uranus (Trinculo) in Italy — ever. Especially in front of a bunch of bored and horny 19 year olds. Don’t ask.
March 7th, 2007 at 3:35 pm
“galaxy harassment” goes over well in the intro classes too. Especially when you explain it using terms like “tickling”.
March 7th, 2007 at 4:31 pm
There’s something so beautiful, so zeitgeisty, about “violent relaxation”. What better describes going to the gym, swimming laps, or any of the other activities that pass for leisure in modern society?
George
March 7th, 2007 at 5:23 pm
Julianne et al., I have to ask — what do you think about the jargon “wet mergers” and “dry mergers”? (Background: “dry mergers” involve galaxies with stars and dark matter, but very little gas; “wet mergers” involve galaxies that have gas, too.)
My picky side is bothered by the inaccuracy (“It’s gas, folks, not water, even if we do call it hydrodynamics.”); the phrases “gas-rich” and “gas-poor” mergers seem clearer and less jargony to me.
Plus, it’s a bit odd, on the border with Creepy, at a meeting to have hundreds of astronomers nattering on about the relative lubrication of their mergers…
March 7th, 2007 at 5:48 pm
In my undergrad quantum corse, the prof taught us about stimulated emission. It was early in the morning, though, and we were all half-asleep, so I’m not sure if anyone actually picked up on it until after he said “don’t laugh.”
March 7th, 2007 at 5:51 pm
Ew! I can’t even think about this.
March 7th, 2007 at 6:17 pm
Julianne– so it isn’t just me that thought “EEK!” that’s reassuring.
Even worse for sheer awkward terminology: The CIII emission line is made by the C+2 atom. Or at least, that’s what Gary Ferland says, though few follow the convention. In this case, the lines were named before electrons were discovered — all the spectroscopists knew was, that when you heat the gas, you get different lines….
Do biologists & chemists put up with such antiquated jargon, too? If not, what’s their secret for deciding on name changes? An add in the paper? “‘Planetary Nebulae’ will henceforth be known as ‘AGN Star Nebulae’. Please make note of it.”
March 7th, 2007 at 6:22 pm
lol you said ‘bulge’
hehe
March 7th, 2007 at 6:29 pm
Not one Uranus joke yet? Our commenters are more mature than I imagined.
March 7th, 2007 at 7:14 pm
The CIII emission line is made by the C+2 atom. Or at least, that’s what Gary Ferland says, though few follow the convention.
Few follow the convention?! Everyone follows the convention. The Roman numeral is always one greater than the ionization.
March 7th, 2007 at 7:19 pm
Which is also why “HII” is singly ionized Hydrogen.
March 7th, 2007 at 8:21 pm
Does it make me a bad feminist if I’m one of the people in the audience who thinks it’s funny when the dry merger discussion leads to the inevitable outcome?
And I suppose “fluid” mergers aren’t much better?
March 7th, 2007 at 8:27 pm
[...] How Galaxies Choose to Relax is Their Own Damn Business [...]
March 7th, 2007 at 9:31 pm
Julianne, I have to give it to you: you always add the spice of explicit sexuality to this blog.
March 7th, 2007 at 10:26 pm
Hairy black holes are pretty fun too.
March 7th, 2007 at 10:27 pm
This blog could use some sexying-up, in my opinion.
But Mark made me promise I wouldn’t share any of those stories he told me.
March 7th, 2007 at 10:33 pm
If Cosmic Variance is responsible for bringing sexy back, then we all are in big, big trouble.
March 8th, 2007 at 1:37 am
Magnetic Confinement Fusion seems to be stuck on food names- Banana orbits, sausage instabilities, kidney bean profiles, etc.
March 8th, 2007 at 2:47 am
Calling Things
Julianne from Cosmic Variance has a hilarious comment about nomenclature in astronomy. I agree that there is some strange slang around that even other physicists might not get. An all-time favourite is of course calling all atoms except Hydrogen and H…
March 8th, 2007 at 2:49 am
I’m amazed a discussion of scientific nomenclature got so far without someone bringing that up…
March 8th, 2007 at 3:48 am
Well Julianne, as galaxies go
The Sombrero Galaxy has everything
It could be a glowing halo
It could be an Etermity Ring, except we know nothing in The Universe is eternal, except perhaps the universe itself (or that from which it proceeded).
It could be the place some men would want to plunge into head first (the place whence they came from), the place of mystery, untold wonders & de-light
If the galaxy is female it could be The bulge means that it is pregnant
If the galaxy is male The bulge could simply means it drinks a lot of bubbles (CO2 from beer or coke) …
or maybe the bulge indicates the galaxy is indeeed happy to see U.
March 8th, 2007 at 4:15 am
I remember shuffling and giggling in the lecture theater when our prof introduced the penetration depth.
March 8th, 2007 at 7:16 am
Somehow, during the late nights studying quantum mechanics with fellow graduate students, the Lippmann-Schwinger equation turned into the Lick-My-Dinger equation (say “my” with a southern accent: “mah”). I don’t know how that happened, but I can’t get it out of my mind.
March 8th, 2007 at 8:50 am
AstroDyke, I totally agree, despite being friends with the person who introduced this terminology. Even worse is when people go so far as to call their sort-of gas-rich mergers “moist”, a word which really should be banned from polite conversation.
Sean, I’ll be happy to bring it up and lower the discourse. In the stairwell outside my door in LASR, there was, among other posters of heavenly bodies, one that says “Explore Uranus”. Even after seeing it every day for 3 years, it never failed to crack me up on my way in to work.
March 8th, 2007 at 9:14 am
Magnetic Confinement Fusion seems to be stuck on food names- Banana orbits, sausage instabilities, kidney bean profiles, etc.
Galaxy dynamics has its share of fun names. Box and tube orbits are a bit utilitarian, but there are banana (and anti-banana) orbits, and pretzel orbits, and fish orbits…
March 9th, 2007 at 1:52 am
The first talk I had to give in a grad astro course was on “ram pressure stripping.” My title page was interesting, though it’s a shame I can’t draw better.
And then I gave a talk on the high helium sequence of Omega Cen. I started thinking about this high sequence, and on one slide I used the words “joint,” “blunt,” “chronic,” and “weed” (as in “this is a chronic difficulty, how to weed out the contamination”). Nobody noticed until I pointed it out… I was so sad.
March 9th, 2007 at 6:24 am
I have nothing to contribute to the subject at hand except to enjoy the various contributions. Add to it a post on Korea’s version of Asimov’s Three Laws of Robotics followed by New Mexico legislating Pluto still a planet and this blog really does live up to the title Cosmic Variance as well as raising a smile and a chuckle on a grey Friday morning here in the UK. Long may you continue
March 9th, 2007 at 2:55 pm
Speaking of astro-nomenclature, I always enjoy the humor that non-astronomer scientists, especially chemists, get from the fact that astronomers divide the matter constituents of the universe into Hydrogen, Helium and Metals.
March 9th, 2007 at 4:25 pm
Mmm, the physics field is _full_ of provocative words; it’s hard _not_ to laugh sometimes.
Once many years ago, I found myself caught in a bit of physics and chess word play in email with someone that I barely knew. I don’t remember which one of us started it, but I think I never laughed as hard in an email conversation as I did with that particular person. Take a look at what you can do with the physics terms.
——
(A provocative chess game in progress here ……)
Do you see that, in this suuuuuuubtle chess game, you are forcing me to ask to your magnetic field to induce MY electric field ?
Check.
You could place your piece in a reference frame where my forces are no longer valid.
You could place your piece in a static magnetic field and let MY moving current loop induce YOUR electromotive force.
You could forfeit the game, and we could alternate the induction.
——
I’ll stop here and let your imaginations fly…. Happy Friday!
March 16th, 2007 at 1:04 pm
In addition to head, mechanical engineers talk about male and female parts of various fasteners, which have obvious visualizations. The list goes on and on, though it’s been awhile since i was in school.
April 25th, 2007 at 9:54 am
[...] Gravitational waves were born from the mind of Einstein in 1918. He noticed that his brand-spanking-new field equations for the general theory of relativity had a simple wave solution in the weak field regime. These solutions represent propagating waves in the fabric of spacetime, traveling at the speed of light. In another fit of creative nomenclature these were dubbed “gravitational waves”. For a ring of particles floating in space, a passing gravitational-wave will cause them to oscillate (image at right stolen from the Wikipedia entry). For an introduction to the theory behind gravitational waves, I highly recommend chapter 7 of a certain textbook. (Sean, I get a kickback, right?) [...]