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This magnetically levitated toy that physics said wouldn’t be stable. The inventor didn’t know that, and stabilized it by spinning.
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Flight of the bumblebee?
How about that New York Times (I think) editorial that declared that rocketry was impossible because any high schooler knew that you needed something other than the vacuum of space to push against to achieve movement? (Both declaration AND proof, as requested?)
No. The Master speaks.
Anyway, even if there ever were such a “proof”, the refutation was well known long before the “proof” was ever imagined.
The scientific ignorance of one journalist is not a proof of anything but the fact that at least one journalist is scientifically ignorant.
Before the invention FM radio, theoreticians had “proved” that it couldn’t be quieter than AM. That is, that FM would be at least as prone to static interference as AM. Edwin Howard Armstrong saw a flaw in the proof and developed FM anyway, ignoring those people who told him he was attempting the impossible. It worked.
The proof that FM would be as noisy as AM assumed that the two systems would share a key characteristic. With AM, the broader the transmission band, the more noise-prone it is. With FM the opposite is true: the broader the transmission band, the less noise-prone it is. The proof assumed that FM would act like AM in this regard. Armstrong understood that it wouldn’t.
This is the only case I can think of where a widely-accepted, supposedly rigorous proof that something was impossible turned out to be wrong.
Continental drift was sort of disproven, i.e. the energy required to move continents through the ocean floor was orders of magnitude too high for any plausible process.
Of course, it turns out that continents are attached to the ocean floor, and they all go riding together, thus eliminating the need to plow through kilometers of rock.
The version I heard of this story was a bit more plausible – although I don’t actually know the facts or details.
What I heard (or read somewhere) was that, earlier on in the 20th century, aerodynamic engineers had proved that the bumblebee could not fly according to all aerodynamic theory known at the time – thus, it was a mystery how the bumblebee did it. The facetious story was “Well, the bumblebee doesn’t know that, so it goes ahead and flies anyway.” This supposedly was before the aerodynamics of the helicopter was known.
Hmmm. I suppose Von Neumann’s famously flawed proof of the impossibility of local hidden variables is the type of thing you’re getting at.
Senegoid: Nice one! (Keynes and the Great Depression . . . )
Come on, Rosemary is hardly a heroine. She’s a victim.
The world record was over 6.5 ft in 1912, and reached 7.4 ft well before the Fosbury Flop.
Here’s the Wiki article.
Enjoyed reading through the quotes from the OP. Here’s one I didn’t see, but one of my favorites:
That is the biggest fool thing we have ever done. The [atomic] bomb will never go off, and I speak as an expert in explosives.—Admiral William Leahy, U.S. Atomic Bomb Project (Comment to President Truman in 1945)
It is a hard question. A proof with a mistake in it, as in a mistake in the mechanics of the proof that should have been known to the person generating the proof can’t really count. A proof that starts with accepted but wrong axioms is much better. The Great Depression example is a wonderful example of bad assumptions, and thus should count.
The converse comes to mind. Russell and Whitehead tried to create a system in which all mathematical proofs could be set. (Bad pun). They found that they simply couldn’t get it to work. It remained for Gödel to show why. Before then however, it wasn’t really questioned that such a thing should be possible, although perhaps difficult, and a lot of work. The fact that it isn’t, and you can prove it isn’t, was a big surprise.
Mostly in mathematics the fun seems to come where you look at the axioms, and wonder what might happen if you relax or change one. As alluded to up-thread. For a long time it was assumed that the parallel postulate simply needed someone cleverer than before to work out the proof. A long and less than glorious history of flawed proofs eventually petered out when non-Euclidian became interesting in its own right, and it became a matter of understanding what your set of axioms was as to where the geometry took you.
That’s what a heroine in a tragedy often is.
Regarding Lord Kelvin and the age of the Earth: it was indeed a conundrum that no one could figure out how the sun could have kept shining for more than a few tens of millions of years. But even at that time geologists were confident that the strata they were familiar with had to be at least several hundred million years old. Given the interrelationship between geology and the fossil record, the geologists at least had no problem with believing evolution had had enough time to work.
I can think of two examples where the proofs of impossibility are technically correct, but the prediction that it will never happen is wrong because of loopholes that were discovered: First, that no material could have a negative index of refraction. This is still technically true, but ignores the possibility of meta-materials that can have an aggregate negative index. Second, the reference upthread to the magnetic toy is referring to Earnshaw’s Theorem, which states that magnetic levitation cannot be stable solely with permanent magnets. What’s commonly overlooked is that the theory itself predicts that the introduction of diamagnetic materials can stablize the levitated object.
I though that Von Neumann’s proof did show the impossibility of a local hidden variables. The “flaw” was that it was commonly interpreted to mean the impossibility of any hidden variable theory, where in reality a non-local hidden variable theory (such as the De Broglie–Bohm theory) can be consistent with quantum mechanics.
Of course he angle sum of a triangle is greater than 180° and less than 540° in *spherical *geometry.
When the first passenger carrying railway was proposed, wasn’t there an eminent doctor who proved conclusively that human beings could not survive speeds greater than 30mph? (I can’t find a cite)
I hope you are referring only to sci-fi movies, otherwise the zombie Katherine Hepburn is going to be very unhappy with you.
Antoine Lavoisier, sometimes called the father of chemistry, proved conclusively that there were no meteorites. All those people that claimed to have seen one were delusional or liars. He conducted scientific tests on a supposed meteorite that proved it was an Earth rock struck by lightning. He concluded that “a stone can not fall from the sky because there *are *no stones in the sky”
Quasicrystalswere believed to be impossible, but one scientist fought long and hard and proved that they exist and won the Nobel Prize in Chemistry for it in 2011. I don’t know if there were any formal proofs for why they shouldn’t be able to exist, but it was the widely held academic belief for decades that he was wrong, until he finally proved them right.
I just thought of another one. Physicists had “proved” that a soap bubble in the shape of a cube was impossible because surface tension minimizes surface area. A guy named Tom Noddy figured out how to do it. The cubic bubble doesn’t stand by itself, but it’s a cube nonetheless. Here he is demonstrating it on the Letterman show.
A lot of folks on this Board asre probably aware that this one:
has been disproven, meaning that neither Duell nor any other Commissioner of the Patent Office ever said it. There was an article on it, covering the topic in great detail several years ago in [Skeptical Inquirer. In fact, it was so popular and important that they reprinted it several years later.
It’s not the only example of a mistaken Expert pronouncement that has appeared in these lists, or in the book The Experts Speak by Navasky and Cerf. My Rule of Thumb is to not believe in such mistaken predictions nor in unfamiliar quotes that I find floating around the internet.