What was once 'Pseudoscience' that is today 'Accepted Science?'
October 14, 2010 2:01 PM   Subscribe

I need help compiling a list of things that have made the jump from "pseudoscience" to established science. It doesn't necessarily have to be recent. An obvious example would be the earth is flat; those advocating the world was round were definitly peddlers of a kind of psuedoscience of its day. Later, they were proved correct. That is what I'm looking for - right up to present day. (more inside)

A more recent example would be those who claimed the brain had an ability to adapt and talked of neuroplasticity. That was once considered silly, a pseudoscience; it's now clearly accepted and established science.

That's the kind of thing I'm looking for. My favorite quotation of the last 100 years is from Donald Rumsfeld (who I strongly disagree with politically). This quote was ridiculed as double-speak and nonsense at the time, but as people really looked at it - there was clearly a lot packed into this quote - to me it's more like poetry:

As we know, there are known knowns; there are things we know we know.
We also know there are known unknowns; that is to say we know there are some things we do not know.
But there are also unknown unknowns -- the ones we don't know we don't know."
- Donald Rumsfeld

That quote sums up my search. What are some things that went all the way from "unknown unknowns" to "known knowns," with a rocky road in the middle. In the things of science, somewhere in the middle of that process, much of what we "know" was considered pseudoscience before it became just plain science. But what are they? What are things that were once considered "pseudoscience" which today would be considered established science? Bonus points to anything that was truly controversial in its travel from "pseudosceince" to science.

As always, thanks in advance to the smartest hive on the web.
posted by Gerard Sorme to Science & Nature (51 answers total) 20 users marked this as a favorite
I assume you mean round.

I believe hypnotism falls into this category - see Mesmer. Also perhaps the germ theory of disease?
posted by bq at 2:06 PM on October 14, 2010

bg...Did I mistype somewhere? I'm probably looking right at it and it's passing me by, but what do you mean, "I assume you mean round?"

Thanks for the hypnotism addition.
posted by Gerard Sorme at 2:09 PM on October 14, 2010

Plate tectonics
posted by Confess, Fletch at 2:09 PM on October 14, 2010 [2 favorites]

Germ theory?

(But check yourself-- Eratosthenes was no pseudoscientist.)
posted by oinopaponton at 2:10 PM on October 14, 2010 [1 favorite]

Plate tectonics was an extremely controversial theory for decades - Alfred Wegener originally proposed the idea in 1912 but it wasn't generally accepted until the 1960s. Even Einstein was a famous skeptic.
posted by theodolite at 2:11 PM on October 14, 2010

Just recently the NYT talked about gargling salt water as a way to ease cold symptoms. There is probably a difference between home remedies and pseudoscience, but not a huge one.
posted by infinitefloatingbrains at 2:12 PM on October 14, 2010

Germ theory is great. Pasteur (and others pursuing the same theory) was definitely considered a quack. Thank you!
posted by Gerard Sorme at 2:13 PM on October 14, 2010

Faculty psychology.
posted by painquale at 2:13 PM on October 14, 2010

Atoms is a good example - Democritus among others was proposing the idea of a smallest possible piece of matter long before it was possible to detect the existence of such a thing.
posted by heyforfour at 2:14 PM on October 14, 2010

This previous thread asks a somewhat similar question.

I think it's important when discussing this type of issue to understand that there is a big difference between pseudoscience and bad science or non-science. The "pseudo" indicates that it is mimicking or disguising itself as legitimate science. The existence of an established scientific community and consensus on appropriate methods is a necessary condition for pseudoscience to exist.

So it isn't really correct to say that "round earthers" were peddling pseudoscience, since those who held the earth was flat weren't representing anything like what we would consider to be a legitimate scientific consensus.
posted by gabrielsamoza at 2:14 PM on October 14, 2010 [13 favorites]

Ulcers were until quite recently thought to be caused by stress or diet. Turns out in 90% of duodenal cases it's a bacterial infection.
posted by Mitheral at 2:14 PM on October 14, 2010 [4 favorites]

"I think it's important when discussing this type of issue to understand that there is a big difference between pseudoscience and bad science or non-science. The "pseudo" indicates that it is mimicking or disguising itself as legitimate science. The existence of an established scientific community and consensus on appropriate methods is a necessary condition for pseudoscience to exist."

Thanks, Gabriel. This is very true. However, we're also quick to judge anything that is outside-the-box as "pseudoscience"; so the misrepresentations clearly go both ways. Thank you for your contribution.
posted by Gerard Sorme at 2:19 PM on October 14, 2010

For clarification purposes to answer your question, what exactly do you mean by pseudoscience? Would that be statements that people make up and coincidentally turn out to be true? Because that's what the word 'pseudo' implies. Or does pseudoscience mean science that is considered revolutionary for its times but is backed with actual scientific proof, however sparse?

those advocating the world was round were definitely peddlers of a kind is true. Most of the people who concluded that the world was round were not wildly speculating, but were concluding from observational and physical evidence (observations of horizons and mountains in the Greek civilization). This idea was revolutionary, but I would not consider this "pseudoscience."

Other examples include: plate tectonics (the continents could actually move? amazing!), the world older than 5000 years as per the Bible, planets revolving around the Sun rather than Earth, the Earth not being the center of the universe, etc.

In other words, all science.
posted by moiraine at 2:22 PM on October 14, 2010 [6 favorites]

Some possibilities (I don't know if these were considered pseudoscience at the time, but they have some characteristics of what you are describing):
- Democritus proposed the notion of atomism back in 400BC, but didn't have a strong scientific basis for it.
- There was a huge debate over dinosaur extinction, with many people not believing that it was an impact by a meteorite for quite a while
- Conventional wisdom for many decades was that ulcers were caused by stress, rather than by bacteria

A minor note, Eratosthenes gave compelling evidence that the Earth was round back in 200BC, but it obviously took a long time for the knowledge to disseminate and for people to believe it.
posted by jasonhong at 2:23 PM on October 14, 2010

Heliocentricism was totally in the category of pseudoscience when it was first advocated in modern times. Copernicus's original heliocentric model didn't actually work that well and came across as more of a philosophical argument or thought experiment than a physical model. The wikipedia commentary, makes this explicit:
the ideas presented by Copernicus were not markedly easier to use than the geocentric theory and did not produce more accurate predictions of planetary positions. Copernicus was aware of this and could not present any observational "proof", relying instead on arguments about what would be a more complete and elegant system. The Copernican model appeared to be contrary to common sense and to contradict the Bible.
However, as observations were refine and orbits more properly modeled, it became clear that heliocentricism was correct.

That said, the roundness of the earth was not regarded as pseudoscience: i think it was pretty much widely agreed that the world was round, just that there was likely no efficient path to asia from europe by sea, and also that there could not possibly be anyone or anything on the antipodes of the round earth.
posted by deanc at 2:23 PM on October 14, 2010 [2 favorites]

Endosymbiosis: it is now widely accepted the mitochondria now living in your cells (and the chloroplasts in plant cells) are descended from what were once distinct prokaryotic organisms. At one time, this theory was thought to be utter hogwash.
posted by AkzidenzGrotesk at 2:26 PM on October 14, 2010

Wouldn't all of psychology fit the bill? Up until the 20th century, nobody tried to conduct any psychological tests. Since a theory was never tested, it was a pseudoscience. After people began to quantify their psychological observations, it became a "real" science.

Under this definition, string theory is a pseudoscience, as well...
posted by chicago2penn at 2:28 PM on October 14, 2010

On preview, what gabrielsamoza said. (I should have typed faster!). I am not being facetious, the question is phrased rather ambiguously. Because, your question implies that all science is pseudoscience! If you need a list of "things that were once considered "pseudoscience" which today would be considered established science," or a list of things that were once "out-of-the-box," then, by your definition, all science is pseudoscience because for a hypothesis to become established theory, people have to question the validity of the hypothesis until a certain degree of proof is established. This is the very basis of the scientific method.
posted by moiraine at 2:30 PM on October 14, 2010

also: i don't think the word pseudoscience means what you think it means. The Copernican revolution was quite scientific in its genesis, but nobody beleived it. This doesn't make it any more or less scientific.
posted by chicago2penn at 2:30 PM on October 14, 2010 [1 favorite]

moiraine beat me to it...
posted by chicago2penn at 2:31 PM on October 14, 2010

Hygiene was regarded as superstitious and without reason for some time before it was recognized that it is good to wash your hands before performing surgery.
posted by TwelveTwo at 2:33 PM on October 14, 2010

Lamarck's theory of inheritance was dismissed after Darwin's evolutionary theories were postulated, but there have been some developments that have led scientists to believe that single celled organisms do exhibit inheritance of acquired characteristics.
posted by tomtheblackbear at 2:39 PM on October 14, 2010

On review of my OP, moiraine and gabrielsamoza are correct. In an effort to get across what I was wanting, I did just the opposite by making just about anything scientific "pseudoscience" at one time. The spirit of what I am wanting has been picked up by many other posters and I appreciate that. Let me make it real simple: The spirit of my question regards controversial scientific theories that were at one time laughed at and later, sometimes even centuries later, became established science.

I don't want to get into too much "discussion" per AskMe rules. I'll let the original question stand as is with this one disclaimer to bring the real question into clearer focus.

Thanks to all.....great answers!
posted by Gerard Sorme at 2:40 PM on October 14, 2010

The popular mythology is that the reason the Portugese turned Columbus away was because they thought the earth was flat.

That's wrong. Everyone knew it was round -- that had been known even back to Greek times. The real question was how big it was. There were two numbers going around. The Portugese believed the bigger one, which had been determined by Eratosthenes. Columbus believed the smaller one.

If the smaller number had been true, it would have been possible for ships of the day to sail from Europe to China by going west. If the larger number were true, they'd have died if they tried it, because it would have been too far for ships of that day.

Now the interesting thing is that the larger number, the one the Portugese believed, was the right answer. Eratosthenes had been within a couple of percent of the actual figure.

Were it not for the accident of there being a new unknown continent in the way, Columbus and his entire crew would have died of starvation.

Your question betrays a degree of pugnaciousness, like you're looking for real citations for the old saw, "They laughed at Einstein, and they laughed at Newton!" or some variation on that theme. But as others here have pointed out, you may not understand what "pseudoscience" really means. There's a critical difference between "pseudoscience" and "unproved hypotheses". (The germ theory was not pseudoscience!)

Another term for it was coined by Feynman, who called it "Cargo Cult science". His speech where he described it is very readable, and coming out of it you may have a better understanding.
posted by Chocolate Pickle at 2:45 PM on October 14, 2010 [9 favorites]

posted by ethnomethodologist at 2:47 PM on October 14, 2010

What comes to mind is the one-time vigorous opposition to anything that smacked of anthropomorphism when discussing animal behavior contrasted with the current knowledge and research in communication and emotion displayed by mammals such as elephants, dolphins and chimpanzees (and others).
posted by Anitanola at 2:52 PM on October 14, 2010

Chocolate Pickle, Actually, I do understand what "pseudoscience" means. I also disagree strongly that Germ Theory was not considered what we've come to call "pseudoscience," when Pasteur and others were trying to prove otherwise.

Comments like, "Your question betrays a degree of pugnaciousness," really serves no purpose here. You may choose to offer an answer to the question - or not. But arguing about my question (when it's even been clarified), and commenting on my "pugnaciousness" is probably out of place here. It is what it is - and it's a valid question. Any further comments along this line can go PM or to chat. Thanks.

To those who clearly "get" my question, your answers are very much appreciated.
posted by Gerard Sorme at 2:54 PM on October 14, 2010 [2 favorites]

I don't want to get too chatfilter-y, but I place "pseudoscience" in the category of claims someone is making because he has a philsophical ax to grind. For example: Aristotle's argument that "the natural state of moving things is to be at rest" (unless they are moving in circles, like planets, because circles are the perfect form). This is a pseudo-scientific belief, superseded by Newton's observational, scientific argument that "things in motion stay in motion, things at rest stay at rest unless acted upon by an outside force." So when I'm thinking about pseudoscience, I'm thinking about some belief someone argued because he had a personal/philosophical belief/insistence that the world should work that way without any good evidence: and it's entirely possible that this belief might by coincidence end up being correct!

But now the OP has argued that this wasn't actually what he was looking for.
posted by deanc at 2:56 PM on October 14, 2010

it was popular that leeches / bloodletting were good for you...
then bad for you....
now good for you... again... but only in certain circumstances (like reattachment surgery)
- however, back to the poing: Bloodletting was about the whole humours thing in general, and that has been banished from medical practice.

acupuncture and reflexology are pseudo-medicine, as the effects are psychological and not physical. maybe you can find more medical-related stuff on http://whatstheharm.net
posted by ChefJoAnna at 3:07 PM on October 14, 2010 [1 favorite]

The spirit of my question regards controversial scientific theories that were at one time laughed at and later, sometimes even centuries later, became established science.

This is a much better question. Pseudoscience is not only not what you're asking about here but it's a pretty loaded term. I'm betting the guys who proved that H. pylorii cause ulcers would be pretty offended to be labelled as pseudoscience, but would happily agree with that characterisation of being previously controversial and unproven.

This question approaches things from the opposite direction to what you've asked but quite a few of the answers are relevant to your clarified question.
posted by shelleycat at 3:26 PM on October 14, 2010

A number of these things aren't "pseudoscience," per se, but hypotheses formed well in advance of the means to support/falsify them. Aurthur Koestler's support of Lamarck was certainly pseudoscientific, but the skepticism around plate tectonics didn't make the theory pseudoscientific, just untested. What makes a claim pseudoscientific are the non-scientific means used to support it, usually by a) someone who has a lot to gain financially from their own hypothesis, or b) as above, someone with an ax to grind.

Having said that, the theory of glaciation was considered quackery for quite some time.
posted by klanawa at 3:31 PM on October 14, 2010

Pseudoscience is something that purports to be science, but isn't science. Science is deriving principles from evidence, and then attempting to disprove them with more evidence.

So claiming the world is round, or flat, is something that can be easily "falsified." If you can see the same stars everywhere, the world is flat. If you can't, then the world is not flat.

Pseudoscience would be proving things by noting the evidence for them but not attempting to find evidence against them. E.g. "I took echinacea and my cold got better, therefore echinacea is a cure for the cold." Science would be "We gave 50 people with colds echinacea, and 50 people water, and in a double blind experiment, the people taking echinacea got better faster." Or not.

The theory of the humors, which lead to bleeding patients, was pseudoscience because it could not be falsified. Applying leeches was pseudoscience because no one attempted to compare patients who had been bled with patients who had not been bled. It would have quickly become clear that in most cases the leaches were hurting the patients. (Modern use of leaches relates to helping blood flow to wounds.)

Pre-Copernican astronomy was science, it was just wrong. Based on the evidence of the sun appearing to move around the earth, astronomers assumed that the sun moved around the earth. Better telescopes allowed them to falsify this theory, disproving it.

Plate tectonics was never "pseudoscience." It was "unproven science." It could be falsified, but not with 1960's technology. String theory can only be falsified with cyclotrons more powerful than we have. But it's still science.
posted by musofire at 3:32 PM on October 14, 2010 [2 favorites]

I've clarified my question - several posts back. I think all the discussion about the definition of "pseudoscience" begged for the clarification and I made one. Can we PLEASE not go over what pseudoscience is/is not, as that's already been stated over and over again. That's why I clarified the question and those who wanted to clarify what "pseudoscience" is to them have done so - several times.

This shows the controversy regarding the term "pseudoscience" and the debate of an accepted definition of the term itself. But, that's not what this question is about. Especially after my clarification, I hoped we can't get back to the real question. To those who have an interest in this question, and have given some wonderful answers, I apologize that my OP caused so much blood pressure to rise. It was my own lack of articulation that caused the derail and I apologize for that.
posted by Gerard Sorme at 3:45 PM on October 14, 2010

However, as observations were refine and orbits more properly modeled, it became clear that heliocentricism was correct.

Specifically, it was when Johannes Kepler articulated the idea of (mathematically defined) elliptical orbits that a heliocentric model became both more elegant and more accurate. Copernicus' mistake was to propose circular orbits.
posted by fatbird at 4:28 PM on October 14, 2010

Gravity and blood circulation. And the general understanding of anatomy has changed quite a bit.
posted by filthy light thief at 4:38 PM on October 14, 2010 [1 favorite]

I'm not sure if this has become accepted or not . . . how about the theory that dinosaurs (at least the very large ones) had to be warm blooded?
posted by IvanKalinin at 5:46 PM on October 14, 2010

Semmelweis proposed handwashing as a method for reducing/eliminating infections during childbirth, and was denounced as a quack for decades afterwards. One of his many angry letters to medical authorities:
My Doctrine is based on my experience. Your teaching, Herr Hofrath, is based on the dead bodies of lying-in women slaughtered through ignorance; and I have formed the unshakable resolution to put an end to this murderous work as far as lies in my power. If, Herr Hofrath, without controverting my teachings, or giving reasons for assuming them erroneous, you continue to teach your students the doctrine of epidemic puerperal fever, I denounce you before God and the world as a murderer, and the History of Puerperal Fever will not do you an injustice when, for the service of having been the first to oppose my life-saving dcotrine, it perpetuates your name as a medical Nero.
posted by benzenedream at 6:03 PM on October 14, 2010 [3 favorites]

Chomsky's argument that all human languages have the same underlying structure rooted in a common neurobiological faculty was certainly resisted as ridiculous for a while in the late 50s and early 60s. Nowadays, it's the outliers who argue that this became the orthodox position too quickly and that there are languages that don't conform to the model. (Others, like me, take the more conventional position that this description does not exhaust the question of what language is or how it works, only establishes a crucial baseline.)

One could also argue that the (modern, relativist) "culture" concept jumped this divide in the hands of Franz Boas and his students in the 30s-40s, in inverse relationship to racist evolutionist theories of innate bases for behavioral differences across human societies.
posted by fourcheesemac at 7:25 PM on October 14, 2010

Oh, a classic example: Robin Warren and Barry Marshall, Australian gastroenterologists whose hypothesis that reflux disease could be caused by a common bacterial infection (h. pylori) and treated with antibiotics was derided as absurd for years until they proved it and won a Nobel prize in 2005.
posted by fourcheesemac at 7:29 PM on October 14, 2010

Not reflux disease, peptic ulcers. Reflux has multiple causes, H. pylori may or may not be one of them.

(and I am reminded once again that I am incapable of spelling that bacterial species name!)
posted by shelleycat at 8:09 PM on October 14, 2010

shelleycat got one. Another is "adult neurogensis." The idea was that there is no new brain cells being generated in an adult. Much evidence that there's a continuous production of new brain nerve cells constantly produced to replenish centers for smell. There's also lots of evidence of neurogenesis in the hippocampus ... and that's implications for learning and memory.

Whether brain/synaptic plasticity was *ever* a "psuedoscience" could be questioned...
posted by porpoise at 9:25 PM on October 14, 2010

Copernicus' mistake was to propose circular orbits.

First, Copernicus did not propose circular orbits. He proposed that planetary motion could be explained by compounding the circular motion of a planet on its epicycle with the circular motion of an epicycle on its deferent. That's not the same as a circular orbit.

Second, nearly 2000 years of celestial mechanics held that the motions of the heavens were uniform and circular. Copernicus objected to the equant point in Ptolemaic astronomy because it implied a circular motion that was *not* uniform. His mistake, from our modern standpoint, was wholly in keeping with millennia of theory.

Third, Kepler's leap from circles to other conic sections--in the event, ellipses--was a far more radical shift than anything Copernicus did. That's not to understate Copernicus's achievement. And Kepler's innovation depended on Tycho Brahe's careful observations.

In short, Copernicus can't really be charged with a mistake in this sense, any more than 18th- and 19th-century physicists can be charged with a mistake for using the Newtonian concepts of mass, force, and acceleration, even though we Einsteinians know that they are, at best, approximations.
posted by brianogilvie at 9:28 PM on October 14, 2010

Traveling faster than the speed of sound.
There was a demon that lived in the air. They said whoever challenged him would die. Their controls would freeze up, their planes would buffet wildly, and they would disintegrate. The demon lived at Mach 1 on the meter, seven hundred and fifty miles an hour, where the air could no longer move out of the way. He lived behind a barrier through which they said no man could ever pass. They called it the sound barrier.
posted by kirkaracha at 9:49 PM on October 14, 2010

Glaciers. More specifically, the idea that glaciers were once more widespread than they are now and are responsible for many geographical features we see today. This was widely mocked at the time.
posted by zachawry at 10:31 PM on October 14, 2010

The Missoula Floods.
Ball lightning.

What everybody (including you) said about science and pseudoscience.

If you want to stir up even more trouble, ask the complimentary question of what used to be considered hard science that is now considered other.
posted by eccnineten at 6:04 AM on October 15, 2010

It bears repeating for emphasis that the OP may not be using the term pseudoscience correctly.

Plate tectonics was not pseudoscience before it was science. It was a scientific theory that wasn't widely supported until more evidence came in.

The germ theory was not pseudoscience before it was science. If the ancient thinkers proposing it were basing their guess on the observed behavior of organisms, it was simply science.

Pseudoscience describes ideas that PRETEND to be scientific by dressing up in a white lab coat, attaching "-ology" to themselves, or inventing a bunch of technical sounding jargon that sounds sciency to people who don't know better.

Healing with Crystals = Pseudoscience
String Theory = Science

posted by General Tonic at 7:16 AM on October 15, 2010 [1 favorite]

The existence of meteorites? "I would more easily believe that two Yankee professors would lie than that stones would fall from heaven."
posted by roystgnr at 10:05 AM on October 15, 2010

General Tonic, you should remember that science is an empirical sport. String theory is immeasurable at any kind of reasonable energy scale (i.e. less than the temperature of the CMB before the time of inflation). It is a completely speculative sport, and thus unscientific in this regard.

Beautiful mathematics, but I wouldn't call it science.
posted by chicago2penn at 10:54 AM on October 15, 2010

chicago2penn, I'm highly skeptical of String Theory, too. But it does make predictions which can potentially be tested and observed, and if found to accurately describe observations, it will mesh with existing scientific knowledge. If the observations are too difficult and cannot ever be made, then string theory should be shelved.

I consider string theory to be science, and probably wrong.
posted by General Tonic at 11:54 AM on October 15, 2010

[that's IT. if you want to debate pseudoscience go to metatalk or email. OP this is way too far afield from your original question. ]
posted by jessamyn (staff) at 4:53 PM on October 15, 2010

Not reflux disease, peptic ulcers.

My bad, sorry. That's correct.
posted by fourcheesemac at 6:25 AM on October 16, 2010

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