Multiplication, not addition. Though I think addition makes more sense in the context of a combined supergroup.
The units are different, so you can’t add them. And you combine groups by the direct product, not by addition.
The units for all are Band Units, so they can be added.
It’s like adding 5 apples + 4 oranges to get 9 fruits.
9 Fruits released a couple of albums in the late ‘70s, but were never a critical or commercial success.
OTOH, the Five Fruits had a runaway smash hit with YMCA. 
I don’t think his spaceship was built for reentry anyway.
This is a rare xkcd with color. One pixel of color, but still.
Is it just me, or are none of those vowel sounds actually schwas? I always figured that the way to recognize a schwa was that, if you replaced it by a different vowel, it’d be hard to notice the difference. Like, for instance, the second vowel in “pencil”: It’d still be recognizably the same word if it were “pensal” or “pensul” or “pensel”. But “Doug” is clearly very different from “Dag” or “Dig”.
Can someone explain the missed rocket burn thingie?
Thanks.
It wasn’t that funny IMHO:
Thank you. That is an awful lot of explanation needed.
(Would have been better visually if the window were round or oval, not square like a picture hung in a lecture hall.)
This strip typically has the driest humor of any comic strip that I’ve ever run across. Makes Arrakis look like the Amazon Basin. It can by turns be clever, insightful, satirical, cute, or silly, or, OTOH, banal, boring, incomprehensible, condescending, or self-defeating.
And if the text said “how badly he’d messed up OUR re-entry burn”
@Zakalwe, thanks for explanation.
I took a fast look at that XKCD and somehow leaped to the conclusion that Sagan had done something about the burn which had caused it to seriously damage the planet. This is probably more my problem than XKCD’s.
and does anybody pronounce onion with two of the same vowel sound? Seems like at least one of them can’t be a schwa.
For me onion definitely has two schwas. The second vowel is a blend of y and schwa. So, ən.jən.
Flat Midwest US accent.
ETA: first vowel may be more of a caret. But those sound very similar to me, with the only difference being the stress.
Huh. I grew up in Texas and have lived half my life in Chicago and pronounce it more like
un-yin
I’m sure sometimes I pronounce the second syllable with a short i vowel. But when going “full speed” I think it drops into a schwa.