Reputations were certainly tarnished, especially in the case of Shockley.
A relatively recent example of the phenomenon is Boyd Haley, an emeritus professor of chemistry at the University of Kentucky, who apparently had a respectable research/teaching career and then went off the deep end, preaching against alleged horrific dangers of amalgam dental fillings and of a mercury-autism “connection” that exists only in the minds of antivaccine advocates and their credulous supporters. Haley’s latest exploit was to market an industrial chelating agent intended to remove mercury from the bodies of autistic children. He tried getting around the law on drug marketing by billing his chelator as a "dietary supplement, but it didn’t fool the FDA.
The main problem with (formerly) respected scientists who become cranks in their own or unrelated fields is not, of course that they’re tarnishing or destroying their reputations. It’s that they and/or their supporters use their prior achievements to add gloss to their crankery (Haley is referenced on innumerable websites devoted to quackery). Linus Pauling’s acolytes are still running an institute dedicated to the proposition that vitamin C (especially in megadoses) is a cure or treatment for a great number of diseases. And who can argue against them - he was a Nobel Prize winner, for chrissake!
At a lower level, Alexander Abian was apparently a perfectly competent mathematician before he went off the deep end and started posting incredibly wacky stuff to Usenet.
(Time has inertia! Equivalence of Mass and Time! Reorbit Venus into a Near Earthlike Orbit to Create a Born Again Earth!)
Nonsense. Wallace did not accept the materialist implications about the human mind/soul that a few people at the time (and more now) drew from evolutionary theory. The fact that you (and perhaps a majority of biologists now, but certainly not then) think he was wrong does not equate to him “going off the deep end.” He was a respected scientist in his time, and he should be (and generally is) now. Also, your words imply (thought you do not say, and may not have intended to) that Wallace was embittered at having been “scooped” by Darwin. Everything I have heard about his career suggests otherwise.
Well, yes, the idea that the forms of living things might evolve over time had been around for a long time, but Darwin and Wallace were the first to clearly understand evolution as involving the differentiation of an ancestor species into more than one descendant species. Both of them came to this realization because of their extensive experience of the way species are distributed in isolated island environments, and both of them got pretty quickly from there to natural selection, so it looks to me as though that view of the structure of evolution, rather than the natural selection mechanism as such, was the real “key.” In later editions of the Origin, indeed, Darwin shows himself prepared to downplay natural selection in favor of other mechanisms (such as Lamarkian inheritance of acquired characteristics). (There were good scientific reasons to be skeptical of natural selection at the time, although later discoveries, of genetics and of radioactivity, defused them.) However, Darwin never wavered in his commitment to evolution by differentiation (and neither did Wallace, to the best of my knowledge).
The older notions of evolution did not have this clear understanding of differentiation. Indeed, Lamark’s theory (by far the clearest and best articulated evolutionary theory before Darwin) explicitly contradicted the idea of differentiation. As Lamark saw things, each modern species had a separate origin, although its form had changed over time. Thus, dogs would have originated as one sort of primitive invertebrate, which had, over time evolved into the modern dog, cats would have originated as quite another form of primitive invertebrate, pythons as yet another, and so on. (I am not sure if he explicitly held that the original, primitive ancestral form of each species was created by God, or if he just left it open.) A large part of Lamark’s motivation (unlike the empirical motivation of Darwin’s and Wallace’s views) was to be able to deny that any species has ever gone extinct. From his perspective, the fact Tyrannosaurs are no longer around is not evidence that they have gone extinct, but that the Tyrannosaur line has evolved into something else (and this solves the problem, a big deal at the time, that if God has created species only to have them go extinct, He must either be a sadist or a screw-up).
As for other “early” evolutionists, such as Erasmus Darwin and Robert Chambers, their accounts are simply too vague for it to be possible to tell what sort of evolutionary pattern, if any, they had in mind. Understanding evolution as differentiation was a crucial advance and, I think, more crucial than realizing that a natural selection mechanism can account for it.
Heisenburgs reputation seemed to weather the war a lot more smoothly then Jordan’s. Partially because he was a pretty ambivalent supporter of the Nazi’s (and indeed, spent most of the thirties being openly accused of being a Jewish sympathizer), and while he later exaggerated his resistence to Nazi Abomb plans, he doesseem to have been geuinely conflicted and made a half-hearted effort to pass German reaactor plans to the allies.
Klaus Fuchs, OTOH, is a good example of a scientist whose WWII activitiesdid some damage to his reputation and career.
James Watson, listed and linked in post #7, is a particularly tragic case. He’s undeniably brilliant and The Double Helix is one of the all-time great books about the humanity of scientists. His unfortunate comments about Blacks, women, fat people et al remind me of the yammerings of an otherwise beloved elderly relative. Well, he had a good run.
Now that you mention it, the OP seems to be looking for examples of scientists who did bad science later in life, as opposed to moral failings, so I guess Heisenberg wouldn’t fit the bill.
There are two that come immediately to mind, both of which were mentioned already.
Dr. Kary Mullis, noted Nobel laureate and certified lunatic.
(Disclaimer - I have met Mullis on numerous occasions. I like him quite a bit - he’s a great guy, but full of the CRAZY. I don’t think i’d like to spend lots of time with him.)
Dr. Peter Duesberg. Member of the national Academy of Sciences and AIDS denier. Kind of sad, really. He was (still is) brilliant, but the HIV stuff has overshadowd everything else he has done. He can’t get funding (for anything), can’t get published, and is professionally shunned - they would have kicked him out of the national Academy if there was any was to do that, but there isn’t to my knowledge.
Here’s a link to an article which in addition to Duesberg, mentions a couple of other scientists who are identified with AIDS/HIV denialism.
Apart from simply wrong convictions, what seems to motivate a number of scientists who’ve gone off the rails is ego - they’re unable to admit mistakes, and appear to groove on the image of being a Brave Maverick who’s defying the corrupt Establishment.
Surprising that Andrew Wakefield took awhile to make the list.
Here’s a gastroenterologist and researcher who exploded onto the scene with what was regarded as a landmark paper suggesting a link between the MMR vaccine and autism. His reputation lasted only a few years before the controversy exploded in his face, amid evidence of sloppy research, unethical recruitment of subjects and concealment of his having been heavily funded by trial lawyers hoping to cash in on suits against vaccine manufacturers.
I’m not sure they really had reputations before the whole cold fusion thing. I’m sure they were known to others in their field, but then, that’s true of all working scientists.
And Quartz, I’ll note that that Wikipedia article on Lathwaite appears to have been, ahem, augmented by his supporters (or possibly himself). The whole paragraph on moths doesn’t fit an encyclopedic style at all, and basically boils down to “But he was right after all!”.
If you could call psychoanalysis a science, I suppose Wilhelm Reich qualifies. A key associate of Freud, he squandered his goodwill on his orgone concept.