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List of common misconceptions beetnemesis Send a noteboard - 05/01/2011 04:33:16 PM
Inspired by today's xkcd, I have made a few selections from this list, and present them to you. Click on the link for the full thing.

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Christopher 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 difficulty of determining longitude without an accurate clock. This problem remained until inventor John Harrison designed his first marine chronometers. The intellectual class had known[1] that the Earth was spherical since the works of the Greek philosophers Plato and Aristotle.[2] Eratosthenes made a very good estimate of the Earth's diameter in the third century BC.[3][4] (See also: Myth of the Flat Earth)

In ancient Rome, there was no wide-spread practice of self-induced vomiting after meals, and Romans did not build rooms called vomitoria in which to purge themselves after a meal.[23] Vomitoria were tunnels underneath the seats of a stadium, through which crowds entered and exited.[24]


# Entrapment law in the United States does not require police officers to identify themselves as police in the case of a sting or other undercover work.[30] The law is specifically concerned with enticing people to commit crimes they would not have considered in the normal course of events.[31]


# Searing meat does not "seal in" moisture, and in fact may actually cause meat to lose moisture. Generally, meat is seared to create a brown crust with a rich flavor via the Maillard reaction.[33][34]


# It is commonly claimed that the Great Wall of China is the only man-made object visible from the Moon.[42] This is false. None of the Apollo astronauts reported seeing any man-made object from the Moon, and even the earth-orbiting astronauts can barely see it. The misconception is believed to have been popularized by Richard Halliburton decades before the first moon landing. Shuttle astronaut Jay Apt has been quoted as saying "...the Great Wall is almost invisible from only 180 miles up."[43]


# 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. The fact that shorter hairs are "harder" (less flexible) than longer hairs also contributes to this effect.[65] Hair can also appear darker after it grows back because hair that has never been cut is often lighter due to sun exposure.


# Sugar does not cause hyperactivity in children.[70] 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. The difference in behaviour proved to be psychological.[71]




# In South 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."[81][82][83][84] Although an airconditioner transfers heat from the air and cools it, a fan moves air to increase the evaporation of sweat. Due to energy losses, a fan will slowly heat a room.



# Humans have more than five senses. Although definitions vary, the actual number ranges from 9 to more than 20. In addition to sight, smell, taste, touch, and hearing, which were the senses identified by Aristotle, humans can sense balance and acceleration (equilibrioception), pain (nociception), body position (proprioception or kinesthetic sense), and temperature (thermoception). [102] Other senses sometimes identified are the sense of time, itching, pressure, hunger, thirst, need to urinate, and need to defecate.[103]


# Ostriches do not bury their heads in the sand. This tale originates from the fact that the male ostrich will dig a large hole (up to 6 to 8 feet wide and 2 to 3 feet deep) in the sand for the eggs. Predators cannot see the eggs across the countryside which gives the nest a bit of protection. The female and male take turns sitting on the eggs and, because of the indention in the ground, usually just blend into the horizon. All birds turn their eggs (with their beak) several times a day during the incubation period. From a distance it may appear as though the bird has its head in the sand.[124]


# The flight mechanism and aerodynamics of the bumblebee (as well as other insects) are actually quite well understood, in spite of the urban legend that calculations show that they should not be able to fly. In the 1930s a German scientist, using flawed techniques, indeed postulated that bumblebees theoretically should not be able to fly,[125] although he later retracted the suggestion. However the theory became generalized to the false notion that "scientists think that bumblebees should not be able to fly."


# It is not true that air takes the same time to travel above and below an aircraft's wing.[145] This misconception, illustrated at right, is widespread among textbooks and non-technical reference books, and even appears in pilot training materials. In fact the air moving over the top of an airfoil generating lift is always moving much faster than the equal transit theory would imply,[146] as described in the incorrect and correct explanations of lift force. beetnemesis here: I find it amazing how widespread this belief is. Anytime the subject came up, this was the explanation in school.



# 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. Normally the thick end of glass would be installed at the bottom of the frame, but it is also common to find old windows where the thicker end has been installed to the sides or the top. In fact, the lead frames of the windows are less viscous than the panes, and if glass was indeed a slow moving liquid, the panes would warp at a higher degree.[150][151]


I was raised Catholic, and it bugs the crap out of me when people get this wrong. I mean, the belief itself is kinda silly to me, but still people, get your faith right! * The Immaculate Conception is not synonymous with the virgin birth of Jesus, nor is it a supposed belief in the virgin birth of Mary, his mother. Rather, the Immaculate Conception is the Roman Catholic belief that Mary was not subject to original sin from the first moment of her existence, when she was conceived. The concept of the virgin birth is the belief that Mary gave birth to Jesus while remaining a virgin.[168]



# 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.[189][page needed][190][page needed]


# 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.[194][195] However, several parts of the German and later the Swiss Autobahn system were indeed designed to be auxiliary military air strips, both during World War II and the Cold War.[196] Additionally, the Swedish Air Force built landing strips into their highway system starting in the 1950s with some expansion continuing into the 1990s.[197] Poland also contains highway strips for landing and takeoff, as well as Finland and Bulgaria.[citation needed]






(There were many more, I just took some of the more interesting ones. Take a look!)
I amuse myself.
Common Misconceptions
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List of common misconceptions - 05/01/2011 04:33:16 PM 968 Views
Nice link. *NM* - 05/01/2011 08:16:18 PM 355 Views
I had great fun with that this morning - 05/01/2011 08:55:28 PM 478 Views
Re: Highway System - 05/01/2011 08:55:54 PM 533 Views
The highway one surprised me, I thought that was true - 05/01/2011 10:27:42 PM 486 Views
re: the searing of meat. "WHAT?!?!?" - 06/01/2011 12:46:41 AM 484 Views
I wouldn't be able to sleep a wink with a fan running all night anyway - 06/01/2011 09:46:04 AM 563 Views
How could belgian highways be visible from space?? - 06/01/2011 12:22:58 PM 573 Views
It's all a matter of how you define "space". - 06/01/2011 07:49:27 PM 453 Views
Unpossible. *NM* - 06/01/2011 09:05:07 PM 217 Views
fans make great white noise generators - 06/01/2011 04:43:25 PM 481 Views
Agreed. - 07/01/2011 12:14:43 AM 535 Views
good old hurricane Alicia - 07/01/2011 04:51:08 AM 417 Views
Sounds like you enjoyed it more than I did. - 07/01/2011 07:06:06 PM 531 Views
I was 17 and had just found out how wondefully different they were - 07/01/2011 07:12:34 PM 481 Views
Darned useful, they are. - 07/01/2011 10:27:05 PM 555 Views
I cry, "foul!" on the senses one. - 07/01/2011 12:12:16 AM 502 Views
That seems reasonable. - 07/01/2011 06:23:54 AM 449 Views

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