What are some things that most scientists once suspected to be true that most scientists today know to be false?
June 9, 2012 2:24 PM   Subscribe

What are some things that most scientists once suspected to be true that most scientists today know to be false?

I recently finished "A Short History of Nearly Everything," and many interesting topics were presented as things we now know aren't true, but even scientists believed them to be true at one time. For instance, many scientists used to believe life spontaneously generated, or that rocks turned into lichen over time.

I'm looking for a few big ideas in science that once held sway and were thought to be true by most learned scientific minds, but later turned out to be false and were accepted as false thanks to the self-correcting nature of science in general.

Links to resources would be greatly appreciated. Thanks.
posted by Lownotes to Science & Nature (32 answers total) 21 users marked this as a favorite
 
Ether.
posted by cmoj at 2:28 PM on June 9, 2012


Luminiferous aether and phlogiston theory?
posted by joe lisboa at 2:28 PM on June 9, 2012


I suppose one of the biggest ones would be the belief that the Earth sat at the center of our solar system/universe.
posted by Thorzdad at 2:29 PM on June 9, 2012


Obvious ones:

The Sun revolved around the Earth
The Earth is flat
Phlogiston
Spontaneous generation
Stellar nucleosynthesis
posted by TheRaven at 2:30 PM on June 9, 2012


Best answer: Wikipedia has a list of superseded scientific theories.
posted by Specklet at 2:30 PM on June 9, 2012 [12 favorites]


Are you looking specifically for things NOT mentioned in A Short History of Nearly Anything? Ether certainly is, among many others.
posted by two lights above the sea at 2:31 PM on June 9, 2012


The history of the model of the atom.
posted by -harlequin- at 2:37 PM on June 9, 2012


Impossibility of passing on "acquired" characteristics [Current thinking = epigenetics]

Deterministic nature of physical reality

[And lots of things (almost everything?) in medicine / public health: dangers of salt, dangers of saturated fat, high carbohydrate diet is best, etc. etc.]
posted by Jon44 at 2:37 PM on June 9, 2012


Er, Everything! A Short History of Nearly Everything
posted by two lights above the sea at 2:39 PM on June 9, 2012


Lysenkoism and Lamarckism.
posted by Blazecock Pileon at 2:40 PM on June 9, 2012 [1 favorite]


Peptic ulcers being caused primarily by the bacterium H. pylori. If you google around you can find a more interesting story, but the gist of it is:

"The H. pylori hypothesis was poorly received,[30] so in an act of self-experimentation Marshall drank a Petri dish containing a culture of organisms extracted from a patient and five days later developed gastritis. His symptoms disappeared after two weeks, but he took antibiotics to kill the remaining bacteria at the urging of his wife, since halitosis is one of the symptoms of infection.[31] This experiment was published in 1984 in the Australian Medical Journal and is among the most cited articles from the journal."
https://en.wikipedia.org/wiki/Peptic_ulcer#History
https://en.wikipedia.org/wiki/Helicobacter_pylori#History

posted by Mr. Papagiorgio at 2:44 PM on June 9, 2012 [1 favorite]


Endosymbiotic Theory of Organelles

And then I was going to say Ulcers and Stress vs. H. pylori but I got beat on that one.
posted by magnetsphere at 2:47 PM on June 9, 2012


Response by poster: Two Lights, I'm most interested in things that were defended in their day and died a hard death because so many people wanted them to be true.
posted by Lownotes at 2:56 PM on June 9, 2012


The scientific consensus used to be that the brain was a fixed, machine-like thing, and that if it got damaged there was nothing you could do about it. Also: that specific functions have a fixed and specific location in the brain. Both turned out not to be true, and the research that discovered that was not immediately well received by neuroscientists at that time (not that long ago). An interesting book about this is "The Brain that Changes Itself" by Norman Doidge.
posted by davar at 2:57 PM on June 9, 2012 [1 favorite]


Best answer: You might be interested in reading Kuhn's The Structure of Scientific Revolutions (please try to enjoy it despite the way that the word 'paradigm' has become a meaningless buzzword in the years since that book's popularity).

As for specific examples, reading the history of any field of science will provide you with many of them.
posted by hattifattener at 3:03 PM on June 9, 2012 [3 favorites]


A lot of medical/biological stuff qualifies.

People use to think that a child's sex was solely determined by the mother, unlike as we now know by the father; also, all failure to conceive children was the woman's fault (whether by her 'willfullness' in denying her husband his rightful heir or because she was 'barren'). And don't forget how they thought that the mother's prenatal experiences would affect her unborn child --- "she was scared by a big dog while she was pregnant, and that's why Little Johnny is terrified of all dogs."

One that I've always thought hilarious, since I've had asthma all my life: people used to think smoking was good for asthmatics: if someone was having an asthma attack, you'd give them a cigarette or even better a cigar "to relax their throat and lungs."

And up until the mid-1800s, it was actually considered foolish for a doctor to wash his hands or instruments --- indeed, the filthier a doctor's frock coat was when he went to deliver a baby, was merely considered proof of that doctor's experience.
posted by easily confused at 3:13 PM on June 9, 2012 [1 favorite]


Until the 1960s, many surgeons believed the heart was untouchable.
posted by Ardiril at 3:30 PM on June 9, 2012


It's in the wiki link, but I love preformism, the theory that sperm has fully formed little people in them.
posted by Garm at 3:32 PM on June 9, 2012 [1 favorite]


I'm most interested in things that were defended in their day and died a hard death because so many people wanted them to be true.

Pluto being a planet.
posted by NoraCharles at 3:34 PM on June 9, 2012 [3 favorites]


During the Restoration, it was widely held that women who did not orgasm did not conceive, so there was a lot of interesting emphasis going on regarding the critical need for heirs. 200 years later, by the time we got to the Victorian era, it was instead held that women had no sexual impulse of any kind. So sad!
posted by DarlingBri at 3:54 PM on June 9, 2012


I've never read that book, but here are some off the top of my head....

Evolution through individuals (as opposed to populations)
http://en.wikipedia.org/wiki/Lamarckism

Miasmas, the spread of disease through "bad air", as opposed to treatable sources (as opposed to the germ theory of disease....poor Semmelweis...)
http://en.wikipedia.org/wiki/Miasma_theory_of_disease
posted by Lt. Bunny Wigglesworth at 4:28 PM on June 9, 2012 [1 favorite]


One famous example (I assume covered in your original text, though) is the widespread scientific rejection of continental drift theory, although there were reasonable bases for this.

Pluto being a planet.

I heh'ed, but it's important to note that nothing about Pluto itself is held to have changed, only the context in which it inhabits the solar system.
posted by dhartung at 5:17 PM on June 9, 2012 [3 favorites]


As a materials engineer, my favorite: Glass is not a slow moving liquid.
posted by blurker at 5:43 PM on June 9, 2012 [1 favorite]


I heh'ed, but it's important to note that nothing about Pluto itself is held to have changed, only the context in which it inhabits the solar system.

Same diff, in a sense: that is basically how a lot of knowledge production works. People in the future are going to comprehend Pluto in an entirely different way, thanks to that contextual change.

Along similar lines, pandas used to be classified as a member of the raccoon family.
posted by vivid postcard at 6:22 PM on June 9, 2012 [1 favorite]


Since Ray Bradbury has just died, it seems apropos to bring up one of the stories from The Illustrated Man: At one time, Venus was considered to be cloudy and rainy. Like Seattle, without coffee.
posted by faceonmars at 10:05 PM on June 9, 2012 [1 favorite]


You can pretty much read all of Aristotle and pick out hundreds if not thousands of things that were widely believed and are wildly wrong. For instance, the idea that primary purpose of breath in animals is to regular inner temperature and that fishes and some other animals do not breathe because they don't generate enough inner heat. Another example is the idea that animals' sensory center was in the middle of the body, not in the brain.

When scientists first started finding fossils in rocks it was thought that they are formed by natural processes as molten rock solidifies. One of the crucial points of evidence to the contrary was the finding of fossilized shark teeth with signs of wear on them.
posted by rainy at 10:06 PM on June 9, 2012


Gah, regular/regulate .
posted by rainy at 10:07 PM on June 9, 2012


People in the future are going to comprehend Pluto in an entirely different way, thanks to that contextual change.

Not to get too far afield, but I think this is related. Part of, I think, the attachment to Pluto's categorization as a "full" planet is some anthropomorphization: the lonely outcast, or the oddball with a weird orbit. But that context was only a perception based on limited instrumentation. Now that we're finding loads of mini-planets out in the far reaches of the solar system, it turns out to be pretty darn routine -- each one is unique, somehow. But people were attached to that view of Pluto, and so they resist conforming classification to the new information.

(Ultimately, of course, there are many fuzzy definitional areas in terms of what is a planet, dwarf planet, asteroid, comet, moon, and so on: all the definitions are arbitrary conveniences. All of them.)

If we return to my static planet vs. continental drift example, people are attached to the idea that the ground beneath their feet is rather stable. Even if the process is over millions of years, they resist because the idea of unstable ground slipping around on a liquid mantle feels wrong. This, too, could connect to anthropomorphized views of Earth itself.

Also related: it's been said that many scientific theories win out not by persuading people from their old positions, but by outliving their opponents.
posted by dhartung at 11:31 PM on June 9, 2012


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.
-- The Right Stuff
posted by kirkaracha at 7:56 AM on June 10, 2012 [3 favorites]


I was restraining myself over the quibbling of terminology... some classifications are a bit, well, quibbly. I'm sure we could fill this board with next classification schemes, but it's not a matter of a "wrong" belief so much as a "more convenient" grouping for the human mind. But then I thought....

Fungi were considered plants for a long time (due to their sessile nature). This was wrong - they do not even show traces of autotrophy. They have since been found to be more closely related to animals. Still, even today some textbooks put fungi in the "botany" area of the book.
posted by Lt. Bunny Wigglesworth at 5:47 PM on June 10, 2012 [1 favorite]


> Miasma theory of disease

Ooh, this reminds me of this excellent story about the discovery, loss of knowledge, and (after needless tragedies) eventual rediscovery of the cause of scurvy (previously on mefi).
posted by hattifattener at 8:10 PM on June 10, 2012


Phrenology..
posted by stumpyolegmcnoleg at 4:17 PM on June 20, 2012


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