I should note for completeness that al-Haytham also lived centuries before Roger Bacon. It's not clear if Roger cribbed, also, but his exhortations to experiment described nothing like the complete system for establishing quantifiable truth found in the Optics.
It's typical, in the European tradition, to credit Francis Bacon with inventing Science. However, Bacon was explicitly cribbing from a man who lived centuries earlier in Egypt and Syria, who actually originated the ideas and methods, and who applied them in an enduring work. The man was Al-Haytham, and the work was his book on optics. He was known at the time in Europe as Alhazen or Alhacen.
Make no mistake: Al-Haytham was fully aware of the importance of his ideas. Bacon deserves credit for also recognizing that importance, and for popularizing the ideas among the notoriously insular English. He does not deserve credit for originating anything so profound.
Thank you, tcpkac, for your concise and clear exposition. All I have to add is that anarchy also leads directly to dictatorship.
The mystery of libertarianism being identical, in practice, to fascism is easy to solve. Simply ignore the expressed goals (i.e. wishful thinking), and concentrate on the predictable consequences of the advocated program. Lo and behold, the program is the same as the fascists', and must therefore lead to the same results. QED.
And no, I'm not "left-wing". The wings are for loonies.
The difference between "libertarian" and "right-wing" is a matter of degree. It corresponds precisely to the degree of honesty in the adherent. That is to say, the libertarian program and the right-wing program are identical in consequence, but libertarians pretend otherwise, through a process called "wishful thinking". An honest right-winger plans to hold a position of power in an ironclad dictatorship, where the libertarian hopes (or claims to hope) that the consequences of the policies he espouses won't actually be that ironclad dictatorship.
In other words, "numbers matter". But I suppose mentioning numbers eliminates most of your audience.
Michael V: I hope you can offer a brief hint by what criterion "dark matter" might be distinguished from "weird physics". (I suspect it will turn out to be very much on-topic, for the site if not the thread.)
Michael V: Dark matter exposes another sort of bias common among scientists. A wide variety of anomalous (or once-anomalous) astronomical phenomena are consistent with plasma fluid-dynamic phenomena at various scales ("geysers" on Enceladus, the Aurora Borealis, solar and galactic jets, too-fast galactic rotation). However, the mathematics of plasma fluid dynamics is fiendishly difficult, and effectively intractable. Progress is possible by performing tricky vacuum chamber experiments, and by simulations on very large supercomputers. Astrophysicists, though, are self-selected from among physicists who don't care for laboratory work, and who enjoy clean mathematical derivations.
(N.B.: Plasma fluid dynamics involves no exotic science at all; it's all just time- and space-varying electric and magnetic fields and (sometimes relativistic) particle flows.)
Parsimony demands that electromagnetic effects be shown to be insufficient before trotting out completely new and property-less "dark" particles and forces. Furthermore, anybody invoking exotic forces should still be obliged to account for the asserted lack of effect from the millions or quadrillions of tons of plasma acknowledged to be in motion in the systems observed.
A proper accounting would need astrophysicists to learn a new field, so of course it won't happen. (One who did would never get papers using it accepted.) Instead, astrophysicists give one another a pass. The rest of us, knowing, may chuckle at their press releases. In the meantime, astrophysicists collect huge masses of detailed data from wonderful new instruments, but remain unable to synthesize it into anything even remotely plausible.
Has this bias exhibited by astrophysicists been named yet? Of course its analog is practically universal outside of science: "to do that I would need to learn, um, math".
Certain observations about scientists' collective behavior long mystified me. Given an established theory that explains old evidence and but not new evidence, and a new hypothesis that also accounts for some new phenomena, scientists routinely demand (and defend demanding!) much more rigorous testing of the new hypothesis than the old theory ever withstood, before they will even accord it parity with the old. Also, when new data actually falsify an old theory, they will go to great lengths to try to rescue it, inventing no end of ad-hoc epicycles. Data that contradicts all known theories is carefully ignored.
My just-so story is that scientists are self-selected as people who Need to Know. To go from one established theory to two alternatives would be to step from knowing to uncertainty. To abandon a falsified theory would be to step from knowing to not knowing. Either of these is intolerable to one who Needs to Know. As a consequence, science is riddled with established, falsified old theories, and routinely ignores both viable new hypotheses and new data that doesn't fit any hypothesis.
If you need concrete examples, consider the quasar (a high-redshift light source) discovered in NGC7319 (an opaque low-redshift galaxy, one of Stephen's Quintet, in Pegasus) a few years back, and since very studiously ignored. Or, consider the standard theory of comet formation, flatly contradicted by every observation, but still trotted out in textbooks and NASA press releases. Each new press release expresses hope that its observations may someday help illuminate dark matter and dark energy, which thus far exist solely to rescue otherwise falsified models of galactic and supergalactic dynamics and cosmology.
Al: Diamond's point is, indeed, that the best approximation to a Singularity we know of is a downfall. He identifies dozens of examples in history and pre-history, from Petra to Yucatan to Easter Island, of exponential development causing collapse. The singular difference between the modern case and his examples that is a cause for hope is that we know the previous examples, and can quantify the process. That knowledge, thus far, is having little effect.
On the flip side, all the previous collapses were local; the Easter Islanders cut down all their own trees, but not everyone else's besides.
Some of Diamond's examples are of collapses consciously averted. New Guinea highlanders evidently noticed, 6000 years after they began doing intensive agriculture, that they were about to eliminate crucial tree species, and instituted woodlots. The Japanese Shogunate did the same a few centuries later. The Shogunate had the authority to enforce its strictures. On New Guinea, perhaps tribes that kept woodlots were able to defeat neighboring tribes that didn't. Neither scenario suggests a method to address modern global crises.