An impossibly heavy noble gas. According to Score Bard's Periodic Table of Blogs, that is.
Well, sort of. The main series in the periodic table of the elements has 7 rows and 18 columns, while Score Bard's periodic table of the blogs has 8 rows and 12 columns. So some interpretation is required.
Language Log (symbol Lu) is in the 8th (bottom) row in the 12th (rightmost) column. The rightmost column in any self-respecting periodic table should certainly be the noble gases (Helium, Neon, Argon, Krypton, Xenon, Radon, Ununoctium). By that analysis, we're one row beyond the heaviest so-far hypothesized noble gas, Ununoctium, whose alleged discovery in 1999 was retracted in 2001. K3wl!
Maybe I'm over-analyzing here. Score Bard writes
Posted by Mark Liberman at April 4, 2004 10:13 AM"This is my blogroll. It's not meant to be authoritative or representative. It's just a color-coded list of the blogs I like. [...] Now, I change it according to my whims. There are no rules."