List of common misconceptions

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This list of common or popular misconceptions contains some fallacious, misleading, or otherwise flawed ideas which are well-documented to be both widely believed and factually incorrect.

History

The Americas

• Columbus's efforts to obtain support for his voyages were not hampered by a European belief in a flat Earth. In fact, sailors and navigators of the time knew that the Earth is spherical, but (correctly) disagreed with Columbus' estimates of the distance to India. If the Americas did not exist, and had Columbus continued to India (even putting aside the threat of mutiny he was under), he would have run out of supplies before reaching it at the rate he was traveling. The problem here was mainly a navigational one, the impossibility of determining longitude without an accurate clock. This problem remained until inventor John Harrison designed his first marine chronometers. The intellectual class had known that the earth was spherical since the works of the Greek philosophers Plato and Aristotle. Eratosthenes made a very good measurement of the Earth's diameter in the third century BC.
• Contrary to the popular image of the Pilgrim Fathers, the early settlers of the Plymouth Colony in present-day Plymouth, Massachusetts did not dress in black, wear buckles, or wear black steeple hats. According to Plimoth Plantation historian James W. Baker, this image was formed in the nineteenth century when buckles were viewed as a kind of emblem of quaintness. This is also the reason illustrators gave Santa Claus buckles.
• George Washington did not have wooden teeth as commonly believed. According to a study of Washington's four known dentures performed by a forensic anthropologist from the University of Pittsburgh (in collaboration with the National Museum of Dentistry, itself associated with the Smithsonian Museum), the dentures were made of gold, hippopotamus ivory, lead, human and animal teeth (including horse and donkey teeth).
• A common misconception among Americans is that Abraham Lincoln's Emancipation Proclamation of January 1863 immediately freed all American slaves. It did not. The Proclamation only pertained to rebelling states. Since those states did not recognize the power of the Federal government, most slaves were not immediately freed as a direct result of the Proclamation. Regions in the South that were under Confederate control when the Proclamation was issued ignored its dictum, so slave ownership persisted until Union troops captured further Southern territory. Immediately affected regions were Tennessee, southern Louisiana, and parts of Virginia. It wasn't until the adoption of the Thirteenth Amendment in 1865 that slavery was officially abolished in all of the United States.

Europe

Napoleon on the Bellerophon, a painting by Charles Lock Eastlake depicting Napoleon Bonaparte, who was taller than his nickname, The Little Corporal, suggests

• Napoleon Bonaparte (pictured) was not especially short. After his death in 1821, the French emperor's height was recorded as 5 feet 2 inches in French feet. This corresponds to 5 feet 6.5 inches in modern international feet, or 1.686 metres. His nickname was le petit caporal (The Little Corporal). There are competing explanations for why he was called this, but few modern scholars believe it referred to his stature.
• Italian dictator Benito Mussolini did not "make the trains run on time". Much of the repair work had been performed before Mussolini and the Fascists came to power in 1922. Accounts from the era also suggest that the Italian railways' legendary adherence to timetables was more myth than reality.
• During World War II, King Christian X of Denmark did not thwart Nazi attempts to identify Jews by wearing a yellow star himself. Jews in Denmark were never forced to wear the Star of David. The Danes did help most Jews flee the country before the end of the war.

Politics

• Al Gore did not specifically state that he invented the Internet. What he did say was, "I took the initiative in creating the Internet". Gore was the original drafter of the High Performance Computing and Communication Act of 1991, which provided significant funding for supercomputing centers, and this in turn led to upgrades of a major part of the early 1990s Internet backbone, the NSFNet, and development of NCSA Mosaic, the browser that popularized the World Wide Web; see Al Gore and information technology.
• John F. Kennedy's words "Ich bin ein Berliner" is standard German for I am a Berliner. An urban legend has it that due to his use of the indefinite article ein, Berliner is translated as jam doughnut, and that the population of Berlin was amused by the supposed mistake. However, the phrase is correct for the intended meaning, and in fact the term Berliner for jam doughnuts is not used in Berlin, where they are generally called (Berliner) Pfannkuchen ("pancakes"). See also: Ich bin ein Berliner.

Law

United States

• Entrapment law in the United States does not forbid police officers from denying that they are police. It is concerned with enticing people to commit crimes they would not, in the normal course of events, have considered.

Cooking

• Searing meat does not "seal in" moisture, and in fact may actually cause meat to lose moisture. Rather, meat is seared to create a brown crust and to add a rich flavor via the Maillard reaction.
• Mussels that do not open when cooked may still be fully cooked and safe to eat.
• Some cooks believe alcohol evaporates quickly when heated, and thus that food items cooked with wine or liquor are non-alcoholic. However, it can take 3 hours or longer to dissipate or burn off all the alcohol, depending on how it is added.
• Sushi does not mean raw fish, and not all sushi includes raw fish. The usual Japanese term for raw fish is sashimi. The term sushi actually refers to the way the rice is prepared with a vinegary dressing. Toppings for the rice may traditionally include raw fish—but also cooked seafood, fish roe, egg, or vegetables such as cucumber, daikon radish, or ume plum. The dish constituting sushi and other fillings wrapped in a seaweed is referred to as makizushi, a type of sushi.
• While putting metal in a microwave can damage the magnetron by causing an impedance mismatch, it depends on the shape and size of the metal and the time it is in the microwave. Electrical arcing may also occur on pieces of metal that are not smooth, or have points (e.g., a fork). Distributed metallic surfaces that are not subject to arcing and do not appreciably alter the magnetron's RF load can be used in a microwave with no danger; examples include the metalized surfaces used in browning sleeves and pizza-cooking platforms.

Science

Astronomy

A satellite image of a section of the Great Wall of China, running diagonally from lower left to upper right (not to be confused with the much more prominent river running from upper left to lower right).

• It is commonly claimed that the Great Wall of China is the only man-made object visible from the Moon. This is false. None of the Apollo astronauts reported seeing any man-made object from the Moon. The misconception is believed to have been popularized by Richard Halliburton decades before the first moon landing.
• Black holes, unlike the common image, do not act as cosmic vacuum cleaners any more than other stars. When a star evolves into a black hole, the gravitational attraction at a given distance from the body is no greater than it was for the star. That is to say, were the Sun to be replaced by a black hole of the same mass, the Earth would continue in the same orbit (assuming spherical symmetry of the sun). Due to a black hole's formation being explosive in nature, the object would lose a certain amount of its energy in the process, which, according to the mass–energy equivalence, means that a black hole would be of lower mass than the parent object, and actually have a weaker gravitational pull.
• When a meteor lands on Earth (after which it is termed a meteorite), it is not usually hot. In fact, many are found with frost on them. A meteor's great speed during entry is enough to melt or vaporize its outermost layer, but any molten material will be quickly blown off (ablated), and the interior of the meteor does not have time to heat up because rocks are poor conductors of heat. Also, atmospheric drag can slow small meteors to terminal velocity by the time they hit the ground, giving the surface time to cool down.
• It is a common misconception that seasons are caused by the Earth being closer to the Sun in the summer than in the winter. In fact, the Earth is actually farther from the Sun when it is summer in the Northern Hemisphere. Seasons are actually the result of the Earth being tilted on its axis by 23.5 degrees. As the Earth orbits the Sun, different parts of the world receive different amounts of direct sunlight. In July, the Northern Hemisphere is tilted towards the Sun giving longer days and more direct sunlight; in December, it is tilted away. The seasons are reversed in the Southern Hemisphere, which is tilted towards the Sun in January and away from the Sun in July. In tropical areas of the world, there is no noticeable change in the amount of sunlight. See also effect of sun angle on climate.
• It is a common misconception that it's easier to balance an egg on its end on the first day of spring. In fact, the ease or difficulty of balancing an egg is the same 365 days a year. This myth is said to originate with the egg of Li Chun, an ancient Chinese folk belief that it is easier to balance an egg on Li Chun, the first day of spring in the Chinese lunar calendar. In Chinese Li=setup/erect; Chun=spring/egg. Setup spring is a Chinese solar term, literally interpreted as erecting an egg for fun. It was introduced to the western world in a Life article in 1945, and popularized once again by self-titled 'urban shaman' Donna Henes, who has hosted an annual egg balancing ceremony in New York City since the mid-1970s.

Human body and health

An incorrect map of the tongue showing zones which taste bitter (1), sour (2), salty (3) and sweet (4). In reality, all zones can sense all tastes.

• Different tastes can be detected on all parts of the tongue by taste buds, with slightly increased sensitivities in different locations depending on the person, contrary to the popular belief that specific tastes only correspond to specific mapped sites on the tongue. The original tongue map was based on a mistranslation by a Harvard psychologist of a discredited German paper that was written in 1901.
• People do not use only ten percent of their brains. While it is true that a small minority of neurons in the brain are actively firing at any one time, the inactive neurons are important too. This myth has been commonplace in American culture at least as far back as the start of the 20th century, as was attributed to William James, who apparently used the expression metaphorically.. Some findings of brain science (such as the high ratio of glial cells to neurons) have been mistakenly read as providing support for the myth.
• There is no single theory that satisfactorily explains myopia—in particular, studies show that so-called eyestrain from close reading and computer games can lead to myopia, but the underlying physiologic mechanism is poorly understood. There is also no evidence that reading in dim light or sitting close to a television causes vision to deteriorate.
• Shaving does not cause hair to grow back thicker or coarser or darker. This belief is due to the fact that hair that has never been cut has a tapered end, whereas, after cutting, there is no taper. Thus, it appears thicker, and feels coarser due to the sharper, unworn edges. Hair can also appear darker after it grows back because hair that has never been cut is often lighter due to sun exposure.
• Hair and fingernails do not continue to grow after a person dies. Rather, the skin dries and shrinks away from the bases of hairs and nails, giving the appearance of growth.
• Although there are hair care products which are marketed as being able to repair split ends and damaged hair, there is no such cure. A good conditioner might prevent damage from occurring in the first place, but the only way to get rid of split ends after they appear is by a hair cut.
• Snapping or cracking one's knuckles does not cause arthritis.
• Sugar does not cause hyperactivity in children. Double blind trials have shown no difference in behavior between children given sugar full or sugar-free diets, even in studies specifically looking at children with attention-deficit/hyperactivity disorder or those considered "sensitive" to sugar. In fact, it was found that the difference in the children's behavior was all in the parents' minds.
• Prolonged exposure to cold weather such as rain or winter conditions does not increase the likelihood of catching a cold. Although common colds are seasonal, with more occurring during winter, experiments so far have failed to produce evidence that short-term exposure to cold weather or direct chilling increases susceptibility to infection, implying that the seasonal variation is instead due to a change in behaviors such as increased time spent indoors close to others. A lowering of body temperature can, however, reduce the body's resistance to an infection that is already present. (See hypothermia)
• It is a common misconception that sleepwalkers should not be awakened. While it is true that a person may be confused or disoriented for a short time after awakening, sleepwalkers may injure themselves if they trip over objects or lose their balance while sleepwalking. Such injuries are common among sleepwalkers.
• In Korea, it is commonly believed that sleeping in a closed room with an electric fan running can be fatal in the summer. According to the Korean government, "In some cases, a fan turned on too long can cause death from suffocation, hypothermia, or fire from overheating." The Korea Consumer Protection Board issued a consumer safety alert recommending that electric fans be set on timers, direction changed and doors left open. Belief in fan death is common even among knowledgeable medical professionals in Korea. According to Dr. Yeon Dong-su, dean of Kwandong University's medical school, "If it is completely sealed, then in the current of an electric fan, the temperature can drop low enough to cause a person to die of hypothermia."
• Warts on human skin are caused by viruses that are unique to humans (Human papillomavirus). Humans cannot catch warts from toads or other animals; the bumps on a toad are not warts.

Biology

• The claim that a duck's quack does not echo is false, although the echo may be difficult to hear for humans under some circumstances, because the quack's sound wave is nearly identical to the echo's sound wave.
• The notion that goldfish have a memory of only three seconds is false. They have been trained to navigate mazes and can recognize their owners after an exposure of a few months.
• Lemmings do not engage in mass suicidal dives off cliffs when migrating. They will, however, occasionally, and unintentionally fall off cliffs when venturing into unknown territory, with no knowledge of the boundaries of the environment. The misconception is due largely to the Disney film White Wilderness, which shot many of the migration scenes (also staged by using multiple shots of different groups of lemmings) on a large, snow-covered turntable in a studio. Photographers later pushed the lemmings off a cliff.
• Bats are not blind. While most bat species do use echolocation to augment their vision, all bats have eyes and are capable of sight.
• It's a common myth that an earthworm becomes two worms when cut in half. This is not correct. An earthworm can survive being bisected, but only the front half of the worm (where the mouth is located) can survive, while the other half dies. On the other hand, species of the planaria family of flatworms actually do become two new planaria when bisected or split down the middle.
• According to urban myth, the Daddy Long-Legs Spider (Pholcus phalangioides) is the most venomous spider in the world. This is false, as the venom this spider carries is far too limited to affect a human. It would take thousands of these spiders to draw one drop. In addition, there is also confusion regarding the use of the name Daddy Long Legs, because Harvestmen (order Opiliones, which are not spiders) and crane flies (which are insects) are also commonly referred to as Daddy Long Legs, and share (also incorrectly) the myth of being venomous.

Evolution

• Biological evolution does not address the origin of life; for that, see abiogenesis. The two are commonly and mistakenly conflated. Evolution describes (and through the theory of evolution, endeavors to explain) the changes in successive generations of organisms, due to differences in genes and gene frequencies that occur in populations of living organisms over time. Thus evolution presupposes that life already exists. Evolution likewise says nothing about cosmology, the Big Bang, or the origins of the universe.
• The word theory in the theory of evolution does not insinuate doubt from mainstream science regarding its validity; the concepts of theory and hypothesis have specific meanings in a scientific context. While theory in colloquial usage may denote a hunch or conjecture, a scientific theory is a set of principles which explain observable phenomena in natural terms. Evolution is a theory in the same sense as germ theory or plate tectonics. (See Evolution is just a theory, not a fact.)
• Humans did not evolve from chimpanzees. Instead, humans and apes share a common ancestor that lived about 5 to 8 million years ago. This common ancestor diverged into two separate lineages, one evolving into modern-day chimpanzees and bonobos, while the other eventually evolved into modern humans.
• Evolution is not a progression from inferior to superior organisms, and it also does not necessarily require an increase in complexity (see evolution of complexity). A population can evolve to become simpler with less genetic information or have a smaller genome, but devolution is a misnomer.

Physics

• Contrary to the common myth, the Coriolis effect does not determine the direction that water rotates in a bathtub drain or a flushing toilet. Generally speaking, the Coriolis effect is only significant at large scales, such as in weather systems or oceanic currents. In addition, most toilets inject water into the bowl at an angle, causing a spin too fast to be affected by the Coriolis effect.
• Gyroscopic forces are not required for a rider to balance a bicycle. However, the stability of a bicycle is improved by gyroscopic forces as well as by its geometry and the rider's ability to counteract tilting by steering.

An illustration of the equal transit-time fallacy.

• It is not true that air takes the same time to travel above and below an aircraft's wing. This misconception, illustrated at right, is widespread among textbooks and non-technical reference books, and even appears in pilot training materials.

Further information: equal transit-time fallacy and lift (force)

• Glass is not a high-viscosity liquid at room temperature: it is an amorphous solid, although it does have some chemical properties normally associated with liquids. Panes of stained glass windows often have thicker glass at the bottom than at the top, and this has been cited as an example of the slow flow of glass over centuries. However, this unevenness is due to the window manufacturing processes used in earlier eras, which produced glass panes that were unevenly thick at the time of their installation. It is not uncommon to find old windows that are thicker at the sides or the top.
• Air is mostly nitrogen, not oxygen. Dry air contains roughly (by volume) 78% nitrogen, 21% oxygen, 0.93% argon, 0.038% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1%.
• The idea that lightning never strikes the same place twice is one of the oldest and most well-known misconceptions about lightning. However, there is no reason why lightning would not be able to strike the same place twice. In fact, lightning strikes the Empire State Building in New York City about 100 times per year.

Chemistry

• Completely pure water is not a good conductor of electricity, and is a good electrical insulator. In practical situations (such as bathtubs, flooded basements) water usually contains impurities (electrolytes) which allow for good electrical conduction.

Scientific method

• There is no single, strict scientific method used by all scientists, a misconception popularized by elementary science textbooks. The rigid hypothesis→experiment→conclusion model of science is an important part of many fields, particularly basic sciences like physics and chemistry, but is not the only way to perform genuine science. Many sciences do not fit well into this mold (astronomy, paleontology, mathematics), and much important scientific work has come from curiosity and unguided exploration, for example, the discovery of cosmic microwave background radiation, or the development of the atomic force microscope.

Sports

• Abner Doubleday did not invent baseball. (See The Abner Doubleday myth.)
• The World Series is not named after the New York World newspaper.
• Cattle (particularly bulls) are not enraged by the color red (something provocative is often said to be "like a red rag to a bull"). Cattle are red-green color-blind. It is not the color of the cape that angers the bull, but rather the movement of the fabric that irritates the bull and incites it to charge.

Religion

• The Immaculate Conception is not synonymous with the Virgin birth of Jesus. Immaculate Conception is the Roman Catholic belief that Mary was herself conceived without original sin. The concept of the virgin birth is the belief that Mary gave birth to Jesus while remaining a virgin.

• Nowhere in the Bible does it say exactly three magi came to visit the baby Jesus, nor that they were kings or rode on camels. It has traditionally been assumed there were three Magi because three gifts are described, and artistic depictions of the nativity after about the year 900 almost always depict three magi. Additionally, the wise men did not visit on the day Jesus was born, but they saw Jesus as a child, in a house as much as two years afterward (Matthew 2:11).

• The forbidden fruit mentioned in the Book of Genesis is commonly believed to be an apple, and is widely depicted as such in Western art, although the Bible does not identify what type of fruit it is. The original Hebrew texts mention only "tree." Early Latin translations use the word "mali", which can be taken to mean both "evil" and "apple". German and French artists commonly depict the fruit as an apple from the 12th century onwards, and John Milton's Areopagitica from 1644 explicitly mentions the fruit as an apple.

• A fatwā is a religious opinion on Islamic law issued by an Islamic scholar, not a death sentence. The popular misconception likely stems from the death sentence pronounced as a fatwā on the author Salman Rushdie in 1989 by Ayatollah Ruhollah Khomeini of Iran, when fatwās first gained widespread media attention in the west.

Technology

Inventions

• Thomas Crapper did not invent the flush toilet; it was invented by Sir John Harrington in 1596. Crapper, however, did much to increase its popularity and came up with some related inventions, such as the ballcock mechanism used to fill toilet tanks. He was noted for the quality of his products and received several Royal Warrants. He was not the origin of the word crap, but his name may have helped popularize it.
• Thomas Edison did not invent the light bulb. He did, however, develop the first practical light bulb, contemporaneously with Joseph Swan.
• Eli Whitney did not invent the idea of interchangeable parts, nor did he invent the cotton gin. He did help to popularize them, and obtained a patent for his cotton gin design.
• Henry Ford did not invent either the automobile or the assembly line. He did help to develop the ideas substantially, sometimes through his own engineering but more often through sponsoring the work of his employees.

Transportation

• The United States Interstate Highway System was not designed with airplane landings in mind. A common urban legend states that one out of every five (or ten) miles of highway must be straight and flat to allow emergency (or military) airplane landings, but this is not the case. However, several parts of the German and later the Swiss Autobahn system were indeed designed to be auxiliary military airports, both during World War II and the Cold War.
• Toilet waste is never intentionally dumped overboard in aircraft. All waste is collected in tanks which are emptied on the ground by special toilet waste vehicles. A vacuum is used to allow the toilet to be flushed with less water and because plumbing cannot rely on gravity alone in an aircraft in motion. The infamous blue ice is caused by accidental leakages from the waste tank.

See also

• Category:Pseudoscience
• Common misunderstandings of genetics
• Conventional wisdom
• Counter-intuitive
• Drug urban legends
• Factoid
• List of cognitive biases
• List of fallacies
• List of memory biases
• List of misconceptions about the brain

• List of misquotations
• List of topics related to public relations and propaganda
• Misnomer
• MythBusters
• Old wives' tale
• Pseudodoxia Epidemica
• QI
• Snopes.com
• Straight and Crooked Thinking
• Urban legend

Further reading

• Diefendorf, David (2007). Amazing... But False!: Hundreds of "Facts" You Thought Were True, But Aren't. Sterling. ISBN 9781402737916.
• Green, Joey (2005). Contrary to Popular Belief: More than 250 False Facts Revealed. Broadway. ISBN 978-0767919920.
• Johnsen, Ferris (1994). The Encyclopedia of Popular Misconceptions: The Ultimate Debunker's Guide to Widely Accepted Fallacies. Carol Publishing Group. ISBN 9780806515564.
• Kruszelnicki, Karl (2006). Great Mythconceptions: The Science Behind the Myths. Andrews McMeel Publishing. ISBN 9780740753640. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• Lloyd, John (2007). The Book of General Ignorance. Harmony Books. ISBN 9780307394910. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• O'Conner, Patricia T.; Kellerman, Stewart (2009). Origins of the Specious: Myths and Misconceptions of the English Language. New York: Random House. ISBN 9781400066605.
• Tuleja, Tad (1999). Fabulous Fallacies: More Than 300 Popular Beliefs That Are Not True. Galahad Books. ISBN 978-1578660650.
• Varasdi, J. Allen (1996). Myth Information: More Than 590 Popular Misconceptions, Fallacies, and Misbeliefs Explained!. Ballantine Books. ISBN 978-0345410498.