Tetragraviton tells us that he doesn't have any understanding for crackpots. Who may exactly boast the label "crackpot" is a bit vague question (despite attempts to quantify the word) – and as you know, I am using a more inclusive definition than others.
But Tetragraviton's basic idea is clear: A crackpot is someone who believes that despite his lack of training, he (or much less often she) can solve the deepest questions that none of the experts could have hacked, or who believes that he's right and everyone else is wrong even if he doesn't have any background in the field. Tetragraviton himself says that he's more careful and often adds qualifiers.
Do I know what Tetragraviton is talking about? Yes. I am regularly exposed to lots of people who may be called crackpots, who have these incredibly naive and seemingly totally unjustifiable beliefs about their being better thinkers than everyone else, about the possibility to solve deep problems by simple slogans and sentences, and who are willing to self-confidently promote arbitrarily silly answers to questions.
On the web, you must have noticed that I may have explosive relationships with people whom I consider crackpots (and for most of them, they are classified in the same way by others). But I also have relatively friendly interactions with some more harmless crackpots. Those have some advantages but they may consume time, too.
But do I feel that I am exactly on the same frequency as Tetragraviton? No. Two weeks ago, we disagreed about whether the physics of decimals is very important. And this arguably "quantitative" difference influences our "slightly" different attitudes to the empathy for crackpots, too.
Nima Arkani-Hamed likes (or at least liked) to say that the best physicists contain the ideal mixture of being very careful, boring, mainstream researchers; and being borderline crazy or crackpots. A genius simply must have some traces of "crackpottery" in him. Although I don't remember the precise words, I agree with this wise observation, too.
This wisdom is similar to a statement I have heard from cosmologist Michael Turner some decades ago. Physics depends on a fine balance between the cold boring empirical facts on one hand; and the hot explosive controversial conceptual speculations on the other hand. When this balance gets violated, physics deteriorates either to botany or to philosophy.
So I think it's obvious that from my perspective, Tetragraviton is too far on the "cold" side of this equilibrium.
That doesn't negate the fact that I share his shock about the ambitious attitude of many crackpots that looks just so obviously silly. They basically believe that they're the smartest people in the world – but without anything that could be interpreted as a rational reason to almost any other intelligent observer.
There are ways for each of us to see that some particular experts – and even whole communities of experts – are smarter, at least when it comes to certain topics. First, even if you disagree with someone's (or a group's) opinions about something, you should be able to pass the exams, get the good grades, get applauded etc. etc. in similar way as they do. To say the least, you should be able to learn how to play their game and pretend that you're thinking in the same way as they do. If you can't do such a thing, it's obvious that they have some skills that you don't have, right?
For example, Alan Sokal managed to publish a hoax postmodern paper about the postmodernist views on mathematics and physics in a prestigious journal. So this was pretty much a proof that the postmodern philosophical babblers, feminists, and similar would-be intellectuals don't have (almost?) any skills that Alan Sokal would lack.
But if you are a crackpot, are you similarly able to publish papers in Physical Review Letters or another journal? At least some journal? And if you have serious problems with such achievements, even in situations when you declared them to be your big goals at some moment, isn't it sufficient for you to see that the experts are more skillful in some respects than you are?
On the other hand, Tetragraviton seems to propose a much more general rule – basically that outsiders can't ever bring revolutionary ideas that are more valuable than what tons of insiders have been doing with years. I clearly disagree with that. Outsiders or at least relative outsiders can do such a thing and they have done such a thing many times in the past. To assume that anything like that is impossible is a sign of a group think or some kind of an intellectual sterility. Also, I would emphasize that great ideas are often (but not always) extremely simple in essence. I am afraid that Tetragraviton would disagree, too.
Again, there are ideas he promoted that I would agree with but I would formulate them differently, with a different focus.
So I would say that the good scientists must have the understanding for the underlying passion and excitement that are the primary drivers of most crackpots' activities. On the other hand, a scientist dramatically differs by much better skills when it comes to self-reflection. An essential ability that crackpots lack – perhaps by definition – is the ability to disprove one's own wrong ideas.
Crackpots typically assume that the real fight is between themselves on one side and the rest of the world or the rest of the scientific community on the opposite side. This format of the fight is an assumption; and all the technical content of their would-be contributions is being adapted to this pre-determined, ambitious format of the war. But it's simply very or insanely unlikely for genuine science to be compatible with this straitjacket.
What an actual great scientist has is a "copy of the whole hostile world" in his own mind. An actual great scientist wants to find the truth. To find the truth, he has to eliminate ideas that are not true. And he just can't wait for the "hostile people in the external world" to do the job. He has to do the job by himself. An honest scientist – and a scientist really must be honest, so the adjective is redundant – simply doesn't just push the cart in one direction. He carefully thinks where the cart should actually be pushed. This is a very different kind of work. So the mind of an actual great scientist – and perhaps even an ordinary scientist – is a battleground where ideas are constantly trying to beat other ideas. And all these ideas and their weapons are being provided by the single brain of the scientist himself. He just doesn't need some "foes" from the external world to identify and kill every wrong idea. He provides these "foes" for himself.
And it's guaranteed that during a long enough research (at least an hour), one unavoidably considers many ideas that are wrong. Some people estimate that top theorists are confused or pursuing ultimately misguided ideas 90% of their time. They should better not published things before they make some sense, however. It's the ability to impartially figure out whether an idea already makes some sense that scientists have and crackpots don't.
Let me express a similar idea differently. Someone has said that the most important lesson that a person in the formative years must experience if he has a chance to become a good scientist is to fall in love with a great idea of hers; and be able to prove that this idea was just wrong. It's needed simply because much of the actual process in the scientific method is about "the killing of ideas". And this is the kind of an experience that crackpots basically lack. They fool themselves into thinking that they have some divine ability to avoid all wrong ideas so everything they ever say has to be deep and true.
Others could give their own stories but I did have several major "ingenious ideas" when I was a teenager whose invalidity – and, to some extent, stupidity – became comprehensible to me months or years later. For example, when I was 14, I got extremely excited by the idea that all elementary particles were "wormholes of different topologies".
You may cut two round balls from the 3D space and identify the two spherical boundaries. You get a regular wormhole in this way. I identified it with the electron. ;-) But you may also cut two "solid tori" from space and identify the two \(T^2\)-topological boundaries (in a way that keeps the space orientable, in all cases). This wormhole of a different topology was the neutrino – and I vaguely explained the toroidal shape by the neutrino's spin (surprisingly, I didn't care about the electron's spin). And you may create a wormhole connecting two "interiors of genus-two surfaces". And that was the proton. A genus-two surface may have a \(\ZZ_3\) symmetry which was enough for me to suspect that the stupid QCD people could have incorrectly concluded that there were 3 quarks inside the proton.
Now, it was beautiful, ingenious, clean. All of matter was created from the pure spacetime geometry. However, when one looks at this idea in some detail, the flaws just become and have to become obvious – otherwise one would be shown to be incompetent. The antiparticles look the same but they should be different. Moreover, the antiparticles and particles can't really get annihilated with each other. The spectrum of constructed elementary particles is demonstrably different from what is needed, and so on. And then there is the prediction of the wormholes of genus higher than two – I apparently didn't care about this interesting (and seemingly wrong) prediction. I don't want to spend too much time with detailed "disproofs" of the idea because everyone who actually understands something like quantum field theory must also be able to figure out what's wrong about similar competing frameworks.
This was extremely far from my only childhood idea that made me thrilled. When I was 10 or so, I had some alternative version of special relativity in which the spacetime had the "purely plus" signature and the problems resulting from that were supposed to be "solved" by a different definition of time slices, and so on. It really didn't make any sense, as far as I can say today – I wasn't even recording the events in a spacetime (or spacetime diagram) in a coherent way. But I thought that the "red Sun in the evening" was some evidence in favor of my theory (which predicted some sort of a Doppler effect, but given by a different formula). I understood the actual special relativity a year later and with this clearer understanding, I could quickly see that pretty much all the details of my theory were wrong and why. The signature has to be mixed. The sunset isn't red because of the Doppler effect of any sort. And so on. I could see how many flaws such a "seemingly convincing" collection of ideas actually has when it's evaluated properly.
But if someone hasn't ever disproved his own wrong idea, he just hasn't started to think as a scientist at all. If that's the case, no amount of passion can compensate for the absence of critical (and self-critical) thinking. The increased self-confidence and passion can only make the person more obnoxious – not more likely to find (and sell) some deep results.
Because the previous paragraph was sort of pro-Tetragraviton, pro-cold, I must end up with the opposite, pro-hot paragraph. The fundamental flaws of the crackpots' thinking may be fixed and when a good scientist does so, he should still be able to recognize that there are some spiritual or emotional aspects of his reasoning in which he is similar to some crackpots, after all – to a similar extent to which science shares some roots with religion. While the crackpots use wrong methods and build on silly ideas even about very fundamental or elementary questions, they may still display a similar kind of the human curiosity, audacity, and independence that has powered and that will power many genuine breakthroughs in science.