25 Things Science Got Totally Wrong

Posted by , Updated on May 23, 2024

In our compilation of 25 Science “Facts” That Were Proven Incorrect, we demonstrated that mistakes in scientific understanding do not imply that science is fundamentally flawed. The core of scientific inquiry involves the likelihood of errors. Its primary goal is to challenge and possibly overturn our existing beliefs. If a hypothesis can be disproven, it is considered incorrect. If it withstands rigorous testing, it is likely correct. That being said, there are numerous outdated and strange scientific theories. Interested in learning more about these debunked ideas? In line with the evolution of science, we present you with 25 Instances Where Science Was Completely Misguided.



The Four Humours

four humoursSource: nlm.nih.gov

For physicians and scientists of antiquity, the body was composed of four humours – phlegm, yellow bile, black bile, and blood. If your body wasn’t producing a healthy balance of these humours, then you would get sick. This is why blood letting was so common up until the 1800’s (then we found out about germs).


Miasma theory

skullSource: livescience.com

This was the idea that miasma (bad air) is responsible for disease. Prior to the introduction of germ theory in the late 1800’s, this was the most widely accepted explanation for why people got sick. The results of this theory led to some rather interesting medical solutions. During the Middle Ages doctors would prescribe “fart smelling.” Apparently it was believed that like cures like, and if bad air caused the disease…bad air could cure it.


The Earth as the Center of the Universe

globeSource: britannica.com

Thanks to Nicolaus Copernicus, the Ptolemaic model of the Solar System (with the Earth at the center), was replaced with our current understanding.



fireSource: britannica.com

Hypothesized in the 1600’s by Johann Joachim Becher, this “element” was meant to explain burning. Also, it was believed that humans didn’t breathe to get oxygen…they breathed to expel phlogiston so they wouldn’t start burning.


Neanderthals and Humans Didn’t Mix

neanderthal and homo sapiensSource: nationalgeographic.com

Actually, after the neanderthal gene was sequenced in 2010, scientists found that up to 4% of people living outside of Africa have neanderthal DNA. This means that there was some cross breeding.


Genetic Variance between Human Races

women of different colorsSource: washingtonpost.com

Actually, there isn’t much genetic variance between human races at all. Recent studies in the 21st century have even shown more variance between African tribes than between Africans and Europeans.


Pluto is a Planet

PlutoSource: nytimes.com

Well, at first it wasn’t. Then it was. And now it isn’t again.


Ulcers are Caused by Stress

bacteriaSource: bbc.com

Wrong. Ulcers are caused by bacteria, and the researchers that proved it actually won the Nobel Prize in 2005. In fact, one of the researchers even ingested the bacteria to prove it.


Flat Earth

flat earthSource: theflatearthsociety.org

While this used to be widely accepted (and widely refuted), there are still people out there that believe this. Just look up the Flat Earth Society.



skullSource: med.stanford.edu

This theory held that inner character was influenced by physical appearance, specifically the measurements of the skull.


The "Unbreakable" Laws of Newtonian Physics

quantumSource: pbs.org

Quantum mechanics completely changed the way we understand the world. On a quantum level, things get crazy in ways that are hard to comprehend.


California Island

beachSource: wired.com

It’s funny because everybody has heard the phrase, “California is an island unto itself.” This metaphorical phrase used to be taken quite literally though. It wasn’t until expeditions late in the 1700’s that map makers realized California was in fact part of North America.



babySource: scientificamerican.com

This was the idea that offspring could inherit traits from the previous mates of their mother. This theory was highly favored among Nazis who believed that an Aryan woman who had intercourse with a non-Aryan man could no longer have a “pure” Aryan child.


Irrational Numbers

piSource: nrich.maths.org

Pythagoras and his followers were almost religiously obsessed with numbers. One of their key doctrines was that all numbers could be expressed as the ratio of integers. So when Hippasus pointed out that the square root of 2 was irrational…it shocked the Pythagoreans, and they had him drowned at sea.


Hollow Earth Theory

earthSource: bbc.com

If you’ve ever read A Journey to the Center of the Earth then you are familiar with this theory. Up until the late 1800’s, some people believed that the center of the Earth might contain, well…nothing.


Growing Lambs

lampSource: wired.com

Although the Greeks were ahead of their time in many ways, they held a crazy belief that you could grow lambs on trees. This belief allegedly arose out of stories coming from the Indies, where people described trees on “which wool grew.” The idea of lambs growing on trees persisted well into the 1600’s.


Time is Constant

clockSource: howstuffworks.com

Not since Einstein. When he showed that light was the only constant, the world thought he was crazy. These days, however, NASA has to adjust its clocks because time runs differently depending on how far you are from a source of gravity and how fast you are going. In fact, a clock at sea level ticks faster than a clock at the top of the Empire State Building.


Complex Organisms = More Genes

dnaSource: sciencedaily.com

Scientists used to think that humans have around 100,000 genes. One of the most surprising things to come out of the Human Genome Project was that we in fact have only about 20,000. And the crazy part? Some tiny moss plants have more than 30,000!


Water Only Found on Earth

waterSource: space.com

As NASA recently discovered, there is more water on Jupiter’s moon of Europa than there is on our own planet.


Apes: the Smartest Non-Human Animal

apeSource: nationalgeographic.com

According to recent research, birds are quite intelligent. In fact, some studies have shown them to be even smarter than apes.


King Tut's Death

King TutSource: nationalgeographic.com

In 2006, historians found evidence that King Tut had died in a chariot accident. In 2014, however, scientists discovered that he had in fact died because of inbreeding.


Intelligence of Neanderthals

skullSource: nytimes.com

In the past, it was thought that Neanderthals died out because Homo sapiens were smarter. New evidence contradicts this. According to researchers, neanderthals may have even been more intelligent than our human ancestors. Why did they die out then? We’re not quite sure.


The Speed of Universe Expansion

universeSource: ox.ac.uk

The prominent view of the cosmos until recently was that the expansion of the universe is slowing down because of gravity. In the 1990’s, however, new evidence showed that the expansion of the universe was in fact speeding up.


Dinosaurs had leathery skin

dinosaurSource: nationalgeographic.com

Actually, scientists have now come to the conclusion that they were mostly covered in feathers.



goldSource: bbc.com

Although Sir Isaac Newton made massive contributions to physics, he remained convinced that he could convert base metals into gold. Thanks to alchemy, however, today we have chemistry.

Photos: Featured Image: Bird (Pexels); Ape (Pixabay) both public domain; text added, 25. The original uploader was Jakob Suckale at English Wikipedia, Four Humours, CC BY-SA 3.0 (unported), 24-22. pixabay (public domain), 21. Matt Celeskey via flickr, CC BY-SA 2.0, 20. shutterstock. 19. wikimedia commons (public domain), 18. pixabay (public domain), 17. wikimedia commons (public domain), 16. pixabay (public domain), 15. Varsha Y S, Varsha 2, CC BY-SA 4.0, 14-6. pixabay.com (public domain), 5. t-bet via flickr, CC BY-ND 2.0 , 4. AquilaGib, Neanderthal skull from Forbes’ Quarry, CC BY-SA 3.0, 3-1. pixabay (public domain)