No matter how many times I read the explanation, I just can’t make the 8 "buffalo"s make sense. Yes, I comprehend the simplified or expanded or substituted forms and see exactly how the trick works. But when trying to read the raw form cold and parse it out I get lost … Every stinkin’ time. In other words, even knowing how the trick works I still fall for it every time.
3 or 4 or 5 "buffalo"s? Sure. But all 8? My feeble mind boggles.
The wiki goes onto state that 8 "buffalo"s isn’t the limit. There is in fact no upper limit to how many "buffalo"s you can string into a single grammatically correct English sentence.
As computer scientists might say: Ain’t recursion plus context-free grammars fun? Not!
Right, stars are made up, basically, of hydrogen and helium, plus a little bit of other stuff, and “metals” is the term used for all that other stuff. Our own Sun, for instance, has a somewhat higher than average metallicity, because it’s got fairly high levels of beryllium, carbon, oxygen, etc. (also lithium, boron, nitrogen, etc., but odd-numbered elements are less common than even-numbered).
Basically, anything not made in the Big Bang is a metal. The BB made hydrogen, helium and trace amounts of a couple others (berylium and lithium), but those trace amounts usually are not counted.
There’s a few other terms where astronomers use an ordinary term in a different way. (I think all sciences do this.)
Halo, when refering to galaxies, does not mean a bright ring above the galaxy’s head (which galaxies do not have, of course). Rather it refers to the area above and below the galaxy’s disk.
Limb means the edge of a planetary or stellar disk.
Standard candles is any kind of light source where all of them have approximately the same intrinsic brightness.
If you don’t understand an xkcd, you can always check this site: explain xkcd (main page).
Pretty much every comic gets an explanation and they begin explaining within the same day that the xkcd gets published. Here is the cosmologist genre comic explanation. Note that for a couple of days - until the next comic is published - those links will show the same comic.
Also, not everyone notices that the xkcd comics have a mouseover which reveals ‘title text.’ The title text is noted directly under the comic in the explain xkcd version. That text for Cosmologist Genre comic says "Inflationary cosmologists call all music from after the first 10^-30 seconds “post-”
Actually, astronomers do make one further distinction beyond “metals”: Anything higher than iron is a “heavy metal”. This is because you can get energy out by fusing lighter elements into iron, but anything heavier than iron, you have to have some other energy source driving the process.
It also occurred to me that chemists often treat hydrogen as a metal (for instance, a chart of the “reaction series of the metals” will include hydrogen). Put that together with the astronomers, and you find that helium is the only non-metallic element in the Universe.
Yea, that doesn’t seem like a great idea to take a perfectly good scientific term (metals) and then co-opt it to mean something different in your field. There is a perfectly good way of solving this problem: Acronyms.
“Metals” was never a “perfectly good scientific term”, even before the astronomers got into it, though. In terms of physical properties, most people wouldn’t consider the likes of sodium to be a metal, but to a chemist, it’s one of the “most metallic” of the elements.
As to Aleph, maybe like the real numbers fancy R or a Phi or Theta, it’s best used as a shield, not a weapon.
Or, in a small size, an Aleph might be a decent throwing star. In a serif-y enough font it’s got lots of sharp points. It’s also very typographically dense, unlike those skinny sticks on the far right that look like they’d break before they’d puncture anyone.
I know I’d hate to get hit with a spinning high speed Aleph; they just look heavy.
