“”Your humble correspondent realizes that many readers are left-wing, anti-string-theory fighters. So they probably smoke marijuana and this is my modest attempt to help them.
|—Marijuana creates holes in lungs|
Luboš Motl is a physicist specialising in string theory. During his active career, he was a competent scientist and an author of mathematics textbooks. What he is mostly, however, is a raging asshole from hell. It's like he thinks this was the secret of Newton's success. Motl was an assistant professor at Harvard University. He got the job through competence and talent, and lost it by being a raging asshole. He has not held a university position since.
Motl is smart, though not nearly as smart as he thinks he is. (It's impossible for anyone to be as smart as Motl thinks he is.) This means everyone who disagrees with him is stupid, probably to the point of criminal negligence.
Motl's Wikipedia article is anodyne, but proudly lists all his arXiv submissions. He has not published a single paper there or anywhere else since 2007, when he split from Harvard. He originally got his Ph.D. scholarship because of a paper he posted on the arXiv as an undergraduate.
 The Reference Frame
His blog, The Reference Frame, consists of abuse and insults hurled at anyone he disagrees with, mostly concerning physics. He has an annoying habit of continuing to edit posts for months after making them, making citation difficult, but at least he doesn't change his stated opinions and makes the abuse and insults more refined. PZ Myers has called Motl a "crackpot" (which is also Motl's favoured word for anyone who disagrees with him). It is true that Luboš is willing to embrace crackpot ideas when it suits his politics. However, his science is generally good within his sphere of competence. The problem is his refusal to recognize that his sphere of competence is finite.
And God help you if you've ever implied anywhere that string theory is anything less than the revealed secret of the universe, particularly if you're Lee Smolin, Peter Woit or "similar breathtakingly dishonest far-left anti-scientific subhuman activist garbage".  Motl has so far failed to keep their papers entirely off the readable categories of arXiv, but not for want of effort.
 Political views
Motl is a climate change denier, having realized that "left-wing groups want to use this carbon theme as a tool for wealth redistribution." His very... distinctive comments can be found on climate change blogs all over the internet (for example, at Stoat, Deltoid, etc.)
“”I think that trash like yourself cannot be debated. It must be destroyed. What is written on the "climate denial" page [in Wikipedia] is just crime, the people who are responsible for it are criminals, and as soon as I get the opportunity to collaborate with someone on their liquidation, I will do it.
| —Lubos Motl commenting on William M. Connolley's blog|
(He didn't mean "anything illegal". Kind of.)
He's a not a big fan of academic feminism either: "Show me a single influential scholar in a department of women's studies who understands the very basic insight about that discipline, namely why virtually all of scholarly feminism is intellectual garbage." 
- ↑ Marijuana creates holes in lungs, The Reference Frame, 2007-06-04
- ↑ Though considering Newton's treatment of Leibniz and Hooke, it kind of was.
- ↑ "I am myself under significant pressure from large groups of crackpots and an effectively infinite sequence of online idiots, many of whom are anonymous and possibly using many pseudonyms to improve their case according to optics of people who are not capable of independent thinking and who judge the truth according to the number of pseudonyms signed under a particular opinion, without realizing that one Motl signature is still more than 50,000 signatures of idiots." Comment, BackReaction, 2006-06-13
- ↑ http://www.nytimes.com/2001/05/01/science/world-science-becomes-global-village-archive-opens-new-realm-research.html
- ↑ Shakin’ the nuts (Pharyngula, 2010-07-23)
- ↑ Tamino vs Goddard (The Reference Frame, 2010-05-11)
- ↑ Venus if you will (CapitalistImperialistPigdog, 12 May 2010)
- ↑ About Lapse Rates in Planetary Atmospheres (CapitalistImperialistPigdog, 14 May 2010)
- ↑ Hep-th papers on Thursday
- ↑ Poland rejects global carbon communism
- ↑ The whole exchange is amusing. In a later comment, Motl clarified: "When I say to liquidate them, I don't mean anything illegal. I just mean the same thing that was eventually done with the Nazis during the second war." Connolley responded with: "Amusingly, I was reading Popper on the Marxists just last night. He lays into them very strongly for using ambiguous language to avoid explicit advocation of violence, but the implications are clear. How odd to find Lubos having this in common with them.", and another commenter followed with a reasonable question: "I often wonder how Lubos talks to his family, friends, colleagues. Or is wife/girlfriend."
- ↑ Noisy picnic and political correctness
- ↑ Oriana Fallaci: Force of Reason