Things We Know That Just Aren't So
We all live with
misconceptions about the world. This is quite normal. No one
can be an expert in everything, so we simplify our learning into
easy-to-remember snippets, which are often very close to the truth,
but never quite there. Generally, our misconceptions are insignificant
and do little harm. Some times they are very significant and do
a lot of harm.
For example, many people believe that when they leave home in winter,
they shouldn't turn off the heat entirely, but rather lower it a
few degrees. If they normally maintain a temperature of 20°C when
at home, when they leave they should turn the thermostat down to
about 15°C. Why? Because they insist that letting the house get
very cold when they are away, and then heating it up again when
they return, uses up significantly more energy than keeping it at
a moderate temperature throughout the day. I have heard this for
years, but never paid much attention to it, largely because when
energy prices were low, it didn't really make much difference. However,
we now face severe energy shortages and the potentially devastating
effects of climate change. So recently when I heard someone say
this, I responded, "As a physicist, I can't see why this would
I didn't insist that
the idea was wrong. As a scientist, I know that general principles
("physical laws") cannot be applied willy-nilly to specific
cases, because unknown local conditions might mute their effects
or cancel them entirely. I therefore decided to research the issue
on the Internet. No matter how man different key words or combination
of key words I tried, I could find no web site that even discussed
the idea. Apparently it was either so widely accepted that it didn't
need discussion, or so patently ridiculous that the experts never
even considered it. After about a half-hour of fruitless effort,
I landed on the site of the United States Department of Energy,
who did feel it necessary to comment on the issue (www.eere.energy.gov/erec/factsheets/thermo.html).
Based on years
of research, they concluded that "the fuel required to
reheat a building to a comfortable temperature is roughly
equal to the fuel saved as the building drops to the lower
temperature. You save fuel between the time that the temperature
stabilizes at the lower level and the next time heat is needed."
In other words, the colder you let your house get when you
aren't there, the more energy you save.
They also dealt with a related misconception. That is, the
higher you set the thermostat, the more heat the furnace will
put out. Thus, if you want the house to warm up from 15°C
to 20°C as rapidly as possible, you should set the thermostat
several degrees higher. However, since the furnace will have
to work harder, you risk damaging it.
Also not true. "Furnaces
put out the same amount of heat no matter how high the thermostat
is set. The variable is how long it must stay on to reach the set
temperature." In short, by turning the heat off completely
when you leave the house, you save valuable energy with no damage
to the furnace. The big danger lies in not turning it off completely.
As noted earlier, most common misconceptions do little harm.
Here are some of my
favorite misconceptions. It is up to you to determine how important
or insignificant they may be in your own life. If you have doubts,
do some research.
Eating at night does not cause
weight gain. It is total calories that count. If your
body requires 2000 calories a day for normal functioning,
then if you take in 2100 calories you will gain weight and
if you take in 1900 calories you will lose weight. Many diet
plans recommend eating small portions throughout the day to
avoid over-eating in the evening, which will almost certainly
result in your taking in more calories than your body needs.
Fasting does not help rid the body of toxins. Fasting
may give the perception of "cleaning out" impurities,
but there is no scientific evidence that this actually happens.
It is more a question of mind over stomach.
"Low fat" does not mean low calories. Low-fat
foods often have the same or more calories than regular versions,
especially for fat-free products. To maintain flavor, fat-free
foods often contain add sugar. Read the label.
Olive oil does
not have fewer calories than other oils. Like the others, olive
oil is 100 percent fat and has essentially the same energy content,
about 120 calories per tablespoon. "Light" olive oil refers
to the flavor, not the calories.
Fresh vegetables are not necessarily more nutritious than frozen
ones. Just-picked vegetables do indeed have more vitamins and
minerals, but they gradually lose their nutrients the longer they
are stored. Vegetables flash-frozen very soon after picking do not
lose their nutrients. So if you prefer fresh vegetables, eat them
immediately; otherwise eat frozen.
Searing a cut of meat does not "seal in" its juices;
it may actually cause the meat to somewhat dry out. Searing consists
of briefly cooking both sides of the meat at a very high temperature,
then reducing the temperature to complete the cooking process. Searing
meat converts surface sugars and amino acids into a caramelized
crust, which enriches its flavor. That is its purpose.
warriors did not wear horned helmets. Horned helmets were used
in Celtic religious rituals. Because they could have easily got
caught on weapons, such helmets were not unsuitable for combat.
Christopher Columbus did not try to prove that the world is round.
Sailors and navigators of the time already knew that the world
was not flat, as did the ancient Greeks. Columbus's objective was
to find a shortcut to India, which turned out to be much farther
away than he had calculated. When he landed in the Americas, he
labeled the native populations "Indians" because he thought
he had reached his goal.
The 13 American colonies did not become independent of Britain
in 1776. This was the year the colonies declared their intention
to achieve full separation from the mother country. However, the
War of Independence (American Revolution), which started in 1775,
continued until the signing of the Treaty of Paris in 1783. The
United States of America officially came into being as a federal
union in 1789.
The words "separation of church and state" do not appear
in the American Constitution. The phrase was first used by Thomas
Jefferson to reassure religious minorities that they would be protected
under the Bill of Rights, the collective name for the first 10 amendments
to the Constitution. The First Amendment actually says: "Congress
shall make no law respecting an establishment of religion or prohibiting
the free exercise thereof."
Napoleon Bonaparte was not abnormally short. At his death in
1821, his height was recorded as 5 feet 2 inches. However, these
were French feet and inches, corresponding to today's 5 feet 6.5
inches (1.69 meters). Napoleon was in fact slightly taller than
an average Frenchman of his time. Most historians believe that his
nickname "the little corporal" (le petit caporal) had
nothing to do with his height.
King Christian X of Denmark did not wear a yellow Star of David
during World War II in defiance of a Nazi edict that his Jewish
subjects would have to do so. Jews in Denmark never did wear the
Star of David. It is true that the Danes were very active in helping
Jews flee the country to avoid persecution and deportation.
Charles Lindbergh was not the first man to fly non-stop across Atlantic
Ocean; he was the first man to do it solo. The first non-stop
trans-Atlantic flight by a team of aviators was achieved by John
Alcock and Arthur Whitten Brown in June 1919. Because of the incredible
endurance needed to achieve the feat, Lindbergh's solo flight in
1927, which lasted 33 hours and 32 minutes, made him an international
The Great Wall of China is not the only man-made object
visible from the Moon. According to the Apollo astronauts, who
went there between 1969 and 1972, no man-made object is visible
from the Moon. The misconception originated from a conjecture by
astronomers decades earlier that if any man-made object could be
seen from the Moon, it would have to be the Great Wall, but it isn't
The "dark side of the moon" is not dark. All parts
of the Moon's surface are illuminated by the Sun roughly half of
the time. The phrase uses the word "dark" in the sense
of "unknown" or "obscure", because the dark
side is never visible from Earth.
A meteor is not hot when it lands on Earth. It appears to be
burning as it flashes through the night sky only because friction
with the atmosphere vaporizes its outer layers of ice. Since its
frozen interior does not have time to heat up, when a meteor hits
the ground it may even be covered with frost.
Polaris, the North Star, is not the brightest star in the northern
hemisphere. Sirius is. Sirius has an "apparent magnitude"
of −1.47 (the lower the number, the brighter the star). Polaris
has an apparent magnitude of just 1.97, meaning that nearly 50 other
stars outshine it. Polaris is so important because it is almost
permanently fixed directly above the north geographic pole, so you
can always determine which direction is north by locating it in
the night sky.
human tongue is not divided into four distinct areas of taste (sweet,
salty, sour, bitter). Taste buds can detect all these taste components
all over the tongue. The original "tongue map" was based
on a misinterpretation of a poorly conducted experiment carried
out in Germany in 1901.
People do not use only 10 percent of their brain. While it is
true that only a small minority of neurons are active at any given
time, the inactive neurons also play a role in controlling body
functions and intelligence.
Shaving does not cause hair to grow back thicker, coarser, and darker.
We get this impression because uncut hair has tapered ends.
Freshly cut hair does not tapered ends, making it seem thicker and
coarser to the touch. It may appear darker because uncut hair is
often bleached by the sun. When cut, the lighter top-layer is removed,
revealing the darker layer underneath.
Hair and fingernails do not continue growing after death. When
a person dies, the skin dries and shrinks away from the base of
hairs and fingernails, giving the appearance of growth.
An exceptionally high proportion of body heat is not lost through
the head. Although a poorly conducted military study once claimed
that "40 to 45 percent of body heat" is dissipated in
this way, more recent studies have shown that loss from the head
is completely proportionate to heat lost elsewhere in the body.
Exposure to rain or
low temperatures does not increase the likelihood of catching a
cold. Colds are caused by a virus; experiments have failed to
produce any evidence that short-term exposure increases susceptibility
to infection. The rise in the number of colds during winter is more
likely to be due behavioral changes, notably increased time spent
indoors with people who already have colds.
Humans cannot catch warts from toads or any other animal. The
bumps on toads are not warts. Warts on human skin are caused by
viruses that are specific to humans only (Human papillomavirus).
Lemmings (a type of small rodent) do not engage in suicidal dives
off cliffs when migrating. Occasionally they fall off cliffs
when venturing into unknown territory, but this is unintentional.
Bats are not blind. Most use echolocation, a type of sonar,
to augment their vision. However, all species of bats have eyes
and are perfectly capable of seeing.
An earthworm does not become two worms when cut in half. When
cut, only the front half, where the mouth is, will survive; the
other half will dry out or starve to death.
It is not true that more than half of all humans who ever lived
are alive today. Or at least it is hard to substantiate this
claim. Other than biblical references, there is no definite starting
point for the human race. Even adopting conservative values for
the start of humanity, population experts generally agree that significantly
less than half of all the people who have ever lived at currently
Using computers does
not damage eyesight. Ophthalmologists say that working on a
computer for long periods may cause the eye to tire and give the
feeling of eyestrain. But the eye is not damaged.
Eating carrots does not improve eyesight. Carrots are rich in
vitamin A, which is essential for sight, but so do many other foods.
A well-balanced diet, with or without carrots, generally provides
all the vitamin A necessary for good vision.
People with weak eyes should not necessarily avoid reading fine
print. The idea that the eye is like a muscle is incorrect;
it is more like a camera. A camera does not wear out faster because
it is used to photograph small objects.
The theory of evolution does not
try to explain the origin of life. It is concerned only with
how species have changed over time, and thus presupposes that life
The theory of evolution does not claim that humans evolved from
apes or monkeys. Rather, it says that humans and other simians
(chimpanzees, gorillas, orangutans, baboons, etc.) all have a common
ancestor that lived some 7 million years ago. In other words, simians
are like the branches of a tree, all starting from a single trunk
but then going their separate ways.
The theory of evolution does not claim that changes in species must
necessarily take millions of years to show their effects. Rapid
evolution has been observed many times both in controlled laboratory
experiments and in nature.
The theory of evolution does not proclaim "the survival of
the fittest", i.e. certain species are considered to be
"strong" are destined to eradicate other species considered
to be "weak". Any species whose members are capable of
reproducing themselves before dying is considered to be "fit".
In other words, the species will survive despite any weakness.
In science, the word "theory" does not indicate doubt.
On the contrary, it denotes a well-defined set of principles that
help explain and make predication about occurrences in the physical
world. A hunch or suspicion still to be tested is called a "hypothesis".
Thus, the theory of evolution, theory of gravity, the theory of
relativity, and a host of other theories are all considered to have
GENERAL SCIENCE Electricity
does not flow through a wire at the speed of light, if by "electricity"
you mean "electrons". Electrons are negatively charged
subatomic particles. When an electric current flows in a wire, the
electrons barely move, but the electrical impulse (electrical signal)
travels from one end of the wire to the other at blinding speed.
It is roughly like what happens when you tap one end of the spring.
The impulse is seen almost immediately at the other end; however,
the individual coils of the spring stay pretty much where they are.
The blue color
of lakes and oceans is not a reflection of the blue sky. When
water molecules encounter light, they absorb red frequencies more
easily than blue frequencies. Blue is reflected, so this is what
we see. Because the effect is small, the blue color becomes evident
only when the water is fairly deep. Shallow water appears colorless.
long distances do not take less time going west-to-east than
east-to-west because of the Earth's rotation. The effect is caused
by jet streams and trade winds, which usually flow in an easterly
The belief that there is no gravity in space is not correct.
Astronauts float and experience other aspects of weightlessness
because they are in orbit. Scientists call this effect "microgravity"
or "simulated zero gravity". A similar sensation is briefly
experienced during skydiving and the rapid descent of an elevator.
Gravity exists everywhere in the universe, although in some places
it may be very slight and difficult to measure.
A "north wind" does not blow north. It is called a
north wind because it comes from the north; it actually blows south.
The same is true of all other winds. A "south wind" comes
from the south and blows north; an "east wind" comes from
the east and blows west, etc.
The frequency and intensity of earthquakes are not increasing.
At least, the people who study these things say so. What may be
true is that their destructive power is increasing because, due
to world population growth, more and more people are living and
constructing buildings where earthquakes happen.
RELIGION The Bible does
not say that the forbidden fruit eaten by Adam and Eve in the Garden
of Eden was an apple. It simple says they ate the "fruit
of the tree". The belief that it was an apple probably comes
from the similarity of the Latin words malus = "bad" and
malum = "apple". Moreover, until as late as the 17th century,
in English "apple" was a generic term for all kinds of
fruits other than berries.
The Bible does not say that Mary Magdalene was a prostitute. In
fact, very little is said about her at all. That she was a prostitute
is an interpretation made by the sixth century Pope Gregory the
The term "immaculate conception" does not refer to the
conception of Jesus by the Virgin Mary, but rather to the Roman
Catholic teaching that Mary herself was conceived without original
"Allah" does not refer to a Muslim god different from
the Christian one. It is simply the Arabic word for God. Arabic-speaking
Christians and Jews also refer to God as "Allah".
The word "jihad" does not mean a "holy war against
Christians", but simply a struggle or striving. One can
have an internal jihad, a family jihad, or a religious jihad, which
does not necessarily mean doing violence to non-Muslims. Likewise,
"crusade" does not mean a "holy war against Muslims",
but a struggle or striving, such as a crusade against child abuse,
a crusade against pornography, a crusade against poverty, etc.
A fatwa is not a death sentence issued by a Muslim cleric, but
rather an interpretation of Islamic law issued by an Islamic scholar.
This popular misconception probably results from the death sentence
pronounced in 1989 as a fatwa on author Salman Rushdie, whose book
The Satanic Verses was considered to be blasphemous.
INVENTIONS Johannes Gutenberg
did not invent the printing press with movable type; these were
already used in China centuries before. He was the first European
to use a press with movable type, which he probably invented without
any knowledge of what the Chinese had already done.
Thomas Edison did not invent the electric light; the idea was
already well known. What he did was invent a gas-filled bulb that
lasted long enough to make electric lighting commercially viable.
Henry Ford did not invent the automobile; rather he invented
a method for manufacturing them at dramatically reduced cost. Before
Ford, automobiles were only for the rich. Ford made them available
The "black box" used to help determine the cause of
airplane crashes is not black. It is bright orange to make it
easier to find and recover from a crash site.
A black belt is not a sign that the holder has achieved supreme
mastery of a martial art. There are several levels of black
belts. While a black belt signifies advanced achievement, it is
still possible for one holder to be more (or less) proficient than
The term "Romance language" is not derived from the word
"romance", meaning a romantic relationship. It derives
from the Latin "Romanus," meaning "Roman".
Frankenstein was not a monster. Victor Frankenstein was in fact
the creator of the monster in the 1818 novel by Mary Shelley. Even
the monster wasn't a monster. As described in the book, he was rather
gentle, but forced to ferociously defend himself against people
who attacked him because of his frightening appearance.
A cold nose does not signify that a dog is healthy. Dogs frequently
lick their nose, which why it is wet. Evaporation of this moisture
in turn makes the nose cold. Thus, a dog sick with fever can still
have a cold, wet nose.
Philip Yaffe is a former
reporter/feature writer with The Wall Street Journal and a marketing
communication consultant. He currently teaches a course in good
writing and good speaking in Brussels, Belgium. His recently published
book In the “I” of the Storm: the Simple Secrets of Writing &
Speaking (Almost) like a Professional is available from Story Publishers
in Ghent, Belgium (storypublishers.be) and Amazon (amazon.com).
For further information, contact: Philip Yaffe Brussels, Belgium
Tel: +32 (0)2 660 0405 Email: [email protected],
The views mentioned above are completely those of the Contributing