Facts
life support system kept Laika alive until the oxygen ran out a few
days later. On April 14, 1958 Sputnik 2 fell into the atmosphere and burned
up. The Soviet Sputnik program sent more than a dozen dogs into space.
The last Sputnik dog was Chernushka (Blackie), whose successful flight
in March, 1961 preceded Yuri Gagarin's manned orbital flight the following
month.
The history of dogs in space http://www.tui.edu/STO/Astronauts/Dogs.html A Fact about Sputnik 1 http://www.cool-fact.com/archive/1998/09/21.html How was food served before plates were invented? Plates for serving food were not used in Europe until the fifteenth
century. Before that, food was usually served on thick, hollowed-out slabs
of stale bread called trenchers, which were specially baked and allowed
to harden so they could hold more food without falling apart. The food's
juices would soak into the bread, and after the meal the soggy trenchers
might be fed to the dogs or offered to poor peasants waiting outside for
leftovers. The evolution of modern plates began when trenchers were carved
out of wood, sometimes with special compartments for spices and condiments.
For a while, wooden trenchers were used as supports for bread trenchers.
Wooden trenchers were later replaced by clay or ceramic plates, which did
not rot under long use. A great site for medieval cookery http://www.godecookery.com/godeboke/godeboke.htm How to set a medieval table http://www.mtsu.edu/~kgregg/dmir/08/0824.html More Facts about food and eating http://www.cool-fact.com/archive/1997/12/16.html http://www.cool-fact.com/archive/1999/01/04.htmlhttp://www.cool-fact.com/archive/1999/12/15.html How did "qwerty" keyboards become standard? Almost every alphabetic keyboard in the world has the letters in
an arrangement called "qwerty," after the first six letters in the top
row. There are several popular myths about the origin of today's standard
keyboard arrangement. Some say it was deliberately designed to slow down
typists. What is the truth? When inventor C. L. Sholes built his first
typewriters in 1868, he arranged the keys in alphabetical order. But the
clumsy mechanical linkages inside the machine could tangle if certain pairs
of keys were struck quickly. The "qwerty" arrangement fixed the tangling
problem by separating the internal links for frequently paired letters,
making the machines more reliable. After a historic typing contest (see
today's Person Of The Day, linked below), "qwerty" became the standard
way to arrange the keys. More about the real history of the "qwerty" keyboard http://home.earthlink.net/~dcrehr/whyqwert.html Reason Magazine article about market myths, including the origins
of "qwerty" and its most popular modern competitor, the Dvorak keyboard
arrangement http://www.reason.com/9606/Fe.QWERTY.html Today's Person Of The Day was the first person to master touch typing
http://www.LearningKingdom.com/person/archive/2000/02/11.html Why are U.S. stock prices quoted in eighths? In the eighteenth century, the U.S. dollar's value was pegged to
the value of the Spanish silver dollar, which was divided into eight parts
rather than the 100 parts (pennies) into which the dollar was divided.
When the U.S. stock market opened at the end of the century, prices were
based on the Spanish dollar, and they were divided into eighths accordingly.
The practice has remained until today, but now the U.S. stock market is
finally preparing to switch to a decimal system. Buying and selling stocks
is a complex, risky art, and the rules change as the world becomes ever
more connected. Here are two resource centers with useful information for beginners
and experts http://www.e-analytics.com/fp16.htm
http://invest-faq.com/ More Facts about money http://www.cool-fact.com/archive/1997/11/27.html Two Words about money http://www.cool-word.com/archive/1998/12/21.html http://www.cool-word.com/archive/1999/03/02.html What causes muscles to cramp? Almost everyone has experienced a muscle cramp. The muscle becomes
contracted and rigid, and is usually quite painful. The contracted muscle
gets locked into a self-sustaining knot, which can last for hours or days.
Many muscle cramps are associated with exercise. These cramps are often
due to a depletion or imbalance of salts in the muscle tissue, especially
calcium, sodium, and potassium, which are lost in our sweat. A buildup
of lactic acid, one of the byproducts of heavy exercise, also can contribute
to the cramping. Such cramps can often be relieved by drinking "electrolyte"
drinks that restore the salt balance. If you get a cramp, it may be helpful
to move the muscle into its least extended (shortest) position and massage
it very gently. Eat something with sodium and potassium (like a banana)
and wait for the cramp to ease. More about muscle cramps http://www.covenanthealth.com/features/health/sports/spor3206.htm Tips for safe exercise, and advice for various sports injuries http://cpmcnet.columbia.edu/texts/guide/hmg24_0002.html Today's Word is charley horse, one name for a severe cramp http://www.cool-word.com/archive/2000/02/15.html More Facts about muscles http://www.cool-fact.com/archive/1998/08/26.html http://www.cool-fact.com/archive/1998/09/10.html http://www.cool-fact.com/archive/1999/08/16.html How does the Earth lose water? Every day, more than 1,000 gallons of water are lost into space
from the top of Earth's atmosphere. Most of the water is lost near the
magnetic poles, where charged particles from the Sun split water molecules
into electrically charged hydrogen and oxygen ions. The charged ions move
in paths that follow the lines of Earth's magnetic field. Since that field
points straight up near the poles, they can escape there. The amount lost
can be much larger during solar storms when the solar wind becomes more
powerful. If Earth had no magnetic field, the amount lost would be far
greater and the oceans would have evaporated millions of years ago. Scientists
suspect that a similar mechanism might have removed water from the atmospheres
of Mars and Venus, both very dry planets today. How Earth's magnetic field protects the atmosphere (and us!) http://wwwssl.msfc.nasa.gov/ssl/pad/sppb/edu/magnetosphere/mag4.html The Polar spacecraft measures the "auroral fountain" of ions http://wwwssl.msfc.nasa.gov/newhome/headlines/ast08dec98_1.htm Facts about auroras, also produced by streams of charged particles http://www.cool-fact.com/archive/1997/07/10.html http://www.cool-fact.com/archive/1998/01/19.html http://www.cool-fact.com/archive/1999/12/30.html Where did guinea pigs come from? In spite of their name, guinea pigs did not originate in Guinea,
nor are they pigs. They are rodents, in the same order as mice and hamsters.
Guinea pigs (Cavia porcellus) were first domesticated 9000-6000 years ago
by the ancient Incas of Peru, who used them for food, as personal pets,
and for religious sacrifices. Their natural range originally extended up
and down the Andes mountain chain, along South America's west coast. Guinea
pigs are social herbivores (plant eaters), adapted to roughly the same
ecological niche as rabbits. Their gnawing front teeth (incisors) are self-sharpening
and continue to grow throughout the animal's life. More about guinea pigs http://www.lpzoo.com/animals/mammals/facts/guinea_pig.html http://www.aracnet.com/~seagull/Guineas/ How did they get the name? To find out, see today's Word http://www.cool-word.com/archive/2000/02/17.html Where did teddy bears come from? A teddy bear is a furry stuffed bear, usually a child's toy. The
toy and its name were born together after a celebrated act of compassion
by U. S. President Theodore "Teddy" Roosevelt. There are several versions
of the story. In the most popular one, Roosevelt went on a bear hunting
trip in November 1902, but no bear was bagged. To give the President a
chance for some kind of trophy, someone tied a bear cub to a tree so he
could shoot it. He refused. Soon after, a cartoon was published in the
Washington Post depicting the incident, and there was a great popular outcry
in favor of the President's thoughtful restraint. An enterprising businessman
began selling stuffed "Teddy bears," and they became an instant hit. History of the teddy bear, including other versions of the story http://www.arts.unimelb.edu.au/amu/ucr/student/1997/chiba/tbh.htm Teddy bears have now been honored on postage stamps http://www.usps.gov/kids/stompfeature49.html Today's Person Of The Day is Teddy Roosevelt http://www.LearningKingdom.com/person/archive/2000/02/18.html How were messages sent before electric telegraphs? Before the invention of the electric telegraph in the mid-1800s,
time- critical messages were sent across long distances by various kinds
of visual telegraph systems (semaphores). Messages were encoded as various
combinations of flag positions or light flashes, sent between hilltop stations
several kilometers apart. In Europe, the main system was a flag semaphore
invented in 1791 by Claude and Ignace Chappe. It used pairs of movable
arms and beams that could represent the letters of the alphabet. By the
use of this system, Napoleon Bonaparte was able to send a message from
Rome to Paris in about four hours at a rate of fifteen characters per minute.
In the United States and England a different system was used in which six
shutters encoded the letters and numbers. Today there are still some cities
with landmarks called Signal Hill or Telegraph Hill, reminding us of their
earlier function. The international two-flag semaphore signalling system http://www.anbg.gov.au/flags/semaphore.html Today's Word is semaphore http://www.cool-word.com/archive/2000/02/21.html How do street lights "know" when to come on? Street lights usually come on around dark, and flick off when the
sun rises. Are they turned on by someone in an office somewhere? Do they
have timers that make them go on and off? Most street lights have photoelectric
sensors that turn them on when the light fades. Look at the top of a street
light. The sensor may be visible as a cylindrical protrusion, often surrounded
by spiky wires designed to keep birds from landing there. Sometimes a street
light will either stay on all day or never come on at all. Each of these
behaviors is usually caused by a defective sensor. You may also notice
a few street lights that turn on, then buzz and go out, only to slowly
brighten up again a few minutes later. These lights are suffering from
aging bulbs that are about to fail. Do you like street lights? You're not alone http://www.eskimo.com/~jrterry/light_pics.html More Facts about public works http://www.cool-fact.com/archive/1998/11/05.html How were croissants invented? The delicate, flaky croissant or crescent roll is a baked pastry
that is curved with pointed tips. Although its popular name in English
speaking countries is French, the roll itself is of Austrian origin, commemorating
a Turkish shape. According to the most popular story, in 1683 the Ottoman
Turks invaded Vienna by trying to tunnel under the city's walls. The Turks
were successfully repelled, thanks to the vigilance of the only people
who were awake during the night-time raid: the bakers. In celebration of
the victory the bakers created the croissant, shaping it like the crescent
found on the Turkish flag. Since there are several different stories of
this event, the true details may be different. But all sources agree that
the croissant's shape is the Turkish crescent, and that it was created
in celebration of an Austrian victory over the Turks. The Turkish Siege of Vienna lasted sixty days http://campus.northpark.edu/history/WebChron/EastEurope/ViennaSiege.html http://www.hillsdale.edu/dept/History/Documents/War/LouisXIV/1683-Vienna-Siege.htm Article about croissants with a full recipe http://frenchfood.about.com/home/frenchfood/library/weekly/aa092898.htm A recipe for "quick and easy croissants" http://www.redstaryeast.net/croiss.htm More Facts about food http://www.cool-fact.com/archive/1997/03/06.html http://www.cool-fact.com/archive/1998/12/02.html http://www.cool-fact.com/archive/1999/12/15.html Why does the Moon look red during a lunar eclipse? When the Earth moves between the Sun and the Moon, it casts its
shadow on its own satellite, causing a lunar eclipse. From the Earth a
bright, full Moon turns into a dark disc that usually has a deep, red color.
Viewed from the Moon, the Earth is much bigger than the Sun, so during
a total lunar eclipse the Sun's disc is completely blocked by the Earth.
Why isn't the Moon plunged into complete darkness during a total lunar
eclipse? When the Sun's light enters Earth's atmosphere at a shallow angle,
it passes through many layers that scatter almost all of the blue and green
light and bend the remaining light around the edge of the planet. The deep,
red light shining on the Moon is the combined light of all the sunrises
and sunsets that are happening on Earth at the moment of the eclipse. A more detailed explanation, with pictures http://spacescience.com/headlines/y2000/ast02feb_1.htm More Facts about the Moon and eclipses http://www.cool-fact.com/archive/1998/04/02.html http://www.cool-fact.com/archive/1998/06/25.html What kind of material has no electrical resistance? In 1911 a Dutch physicist named Heike Kamerlingh Onnes noticed that
when he cooled mercury metal to a temperature just above absolute zero
its electrical resistance completely disappeared. He had discovered superconductivity,
a property that some materials have at very low temperatures. When all
electrical resistance disappears, some strange things happen. Electric
currents can flow forever in closed loops through the material. External
magnetic fields cannot enter because they cause exactly equal and opposite
currents to flow, repelling them. Scientists are still trying to understand
superconductivity. One of the great mysteries is whether there are materials
that can show superconductivity at high temperatures. New superconducting
materials are discovered every year, but so far they all must be cooled
to very low temperatures before they become superconductors. All about superconductors http://superconductors.org/ More Facts about electricity http://www.cool-fact.com/archive/1998/12/11.htmlhttp://www.cool-fact.com/archive/1999/10/14.htmlhttp://www.cool-fact.com/archive/1999/10/27.html What were the first creatures with compound eyes? The first eyes with more than one simple lens belonged to bottom-
dwelling, aquatic creatures that lived more than 500 million years ago.
Scientists suspect that through mutation some of these primitive creatures
were born with multiple eyes, instead of one on each side of the body.
The multiple eyes probably gave them greater light-gathering ability, an
advantage in deep or muddy waters, and over time evolution made their eyes
more effective. In their descendants the trilobites compound eyes became
quite complex, some of them containing as many as 20,000 lenses Today's
insects, which also came from the same ancestors, bear compound and simple
eyes adapted for many different lifestyles. Among the best are those of
dragonflies, who can track tiny insects on the wing and scoop them up for
dinner. How does a bee see the world? Here's one scientist's educated guess
http://cvs.anu.edu.au/andy/beye/beyehome.html A surprising finding about one kind of insect's compound eyes http://www.sciam.com/exhibit/1999/110899bug/ More Facts about eyes http://www.cool-fact.com/archive/1997/05/19.html http://www.cool-fact.com/archive/1998/03/16.html http://www.cool-fact.com/archive/1998/07/08.html Why do tiny particles jiggle around? Look through a powerful microscope at a water suspension of tiny
particles like pollen grains, bacteria, or just plain old dirt and you
may notice that they are jumping and jiggling around. Why do they jiggle?
The jiggling is called Brownian motion, after the Scottish botanist Robert
Brown, who noticed it in 1828. While Brown could not explain the jiggling
motion, we know today that it is the result of the movements of water molecules.
Smoke particles floating in the air also show Brownian motion. All molecules
are in motion all the time, even at a temperature of absolute zero. At
room temperature, the chaotic, unpredictable movements of water molecules
are strong enough that much larger particles get bounced around, and the
bouncing is visible under the microscope. Two pages with java applets that model brownian motion http://www.geocities.com/SiliconValley/Vista/6175/brownian.htmlhttp://xanadu.math.utah.edu/java/brownianmotion/1/ More Facts atoms, molecules, and movement http://www.cool-fact.com/archive/1997/10/16.htmlhttp://www.cool-fact.com/archive/1998/11/18.htmlhttp://www.cool-fact.com/archive/2000/02/02.html What was the best throwing weapon before bows? Before the bow and arrow were invented about 15,000 years ago, a
simpler weapon was used to throw long darts with great power and accuracy.
The atlatl [at-LAT-ul] was invented at least 25,000 years ago, and is still
used by Australian aborigines. The atlatl is a stick about 60 centimeters
long (24 inches), with a notched hook at one end. Into the notch is placed
the end of a flexible, feathered "dart" that is at least 150 centimeters
long (59 inches) and possibly longer. By flicking the atlatl quickly forward,
the user is able to fling the dart toward the target with tremendous speed.
Recently, there has been a surge of interest in the atlatl. Its physics
are surprisingly sophisticated, involving temporary storage of energy in
the flexing of the dart as it is thrown. Enthusiasts are now designing
ever-better atlatls using high-tech materials, and there are world-wide
competitions. The World Atlatl Society http://www.worldatlatl.org/ World Atlatl Magazine http://www.atlatl.net/ More Facts about weapons http://www.cool-fact.com/archive/1997/03/08.htmlhttp://www.cool-fact.com/archive/1998/04/17.htmlhttp://www.cool-fact.com/archive/1999/09/28.html What's the largest visible light telescope? Until 1993, the largest light telescope in the world was the 200-inch
(5-meter) Hale Telescope at the top of Mt. Palomar in southern California.
With its huge single-piece glass mirror, it was a tremendous feat of engineering.
In 1993, the gigantic 400-inch (ten-meter) Keck I Telescope was completed.
At the top of Hawaii's dormant Mauna Kea volcano, it is eight stories tall
and weighs 300 tons. In 1996 its twin, the Keck II, was brought online.
Instead of a single continuous mirror, each Keck Telescope has thirty-six
thin hexagonal segments that can be individually aligned for maximum accuracy.
With its huge collecting area, each Keck can gather forty thousand times
as much light as the telescope that Galileo used. The twin Keck Telescopes http://www2.keck.hawaii.edu:3636/realpublic/gen_info/gen_info.html More Facts about telescopes and other seeing instruments http://www.cool-fact.com/archive/1998/04/13.htmlhttp://www.cool-fact.com/archive/1998/11/17.htmlhttp://www.cool-fact.com/archive/1999/08/03.html How are horse's hooves protected from cracks? The hooves of a galloping horse can hit the ground with more than
the weight of the entire animal, yet they are made of keratin, the same
protein that makes up your fingernails. How do they keep from cracking
under the stress? A horse's hoof is essentially a huge toenail. But unlike
human toenails, it has an internal structure that stops cracks before they
can grow, and even shunts them off to the edge of the hoof, thus trimming
it efficiently by removing extra "flash" from the edges. The keratin protein
of the hoof has a "grain" like the grain of wood. Cracks tend to grow along
that grain. If a crack develops, it moves along the grain until it comes
to one of thousands of microscopic tubes that run through the hoof. Each
tube is wound with layers of protein with differently-pointing grain, which
redirect the crack along the tube to the edge of the hoof, where it harmlessly
ends. More about horse's hooves and hoof cracks, which can still happen
in spite of nature's excellent protection http://www.thehorse.com/0698/hoof_cracks0698.htmlhttp://www.webaccess.net/~cherryhillbooks/INFOhoofdress.htm More Facts about horses http://www.cool-fact.com/archive/1997/02/25.htmlhttp://www.cool-fact.com/archive/1998/08/26.html Why isn't this popular Asian fruit allowed on airplanes? All across southeast Asia, people eat the durian or stinkfruit (Durio
zibethinus). Westerners who try them are often astonished at the smell,
which has been described as a blend of decayed onion, turpentine, garlic,
Limburger cheese, and resin. Although the flesh of the durian is sweet
and mild, the aroma is so strong that many westerners cannot consume it
without gagging. Eating it on commercial flights has been forbidden by
several Asian airlines. Yet the durian is enormously popular in Asia. In
Thailand, it is called the King Of Fruits. This spiky-skinned, brownish
green fruit, which can grow as big as a human head, is becoming available
in the United States and Europe. Watch for it in gourmet supermarkets --
but be prepared! More about the amazing durian http://www.sunfood.net/fruits/durian.html Daniel eats Durian fruit http://durian.net/durian_daniel_eat.htm The King and Queen of tropical fruit, with recipes http://www.proscitech.com.au/trop/d.htm More Facts about fruit http://www.cool-fact.com/archive/1997/10/28.html http://www.cool-fact.com/archive/1998/07/10.html http://www.cool-fact.com/archive/1999/09/02.html How thick is Earth's crust? Most of the Earth is made of relatively heavy rock and metal. The
crust is a layer of lighter material that floated to the top when the planet
was still almost all molten. It makes up only 1% of the total volume of
the planet. The crust varies in thickness, from five kilometers (three
miles) under the deepest parts of the ocean to 70 kilometers (43 miles)
under the highest continental mountain ranges. How thin is it, compared
to the planet's size? Imagine that the Earth is the size of an orange.
Under the deepest oceans, the crust would be thinner than tissue paper,
while under the biggest mountain ranges it would be about as thick as construction
paper. A great page all about Earth http://www.seds.org/nineplanets/nineplanets/earth.html More Facts about our planet http://www.cool-fact.com/archive/1997/03/16.html http://www.cool-fact.com/archive/1997/12/22.html http://www.cool-fact.com/archive/1999/06/09.html What happens when you make a snowball? When you make a snowball, you squeeze together a scoop of snow and
it clumps into a semi-solid mass. Why does it do that? Do the snowflakes
get caught on one another? How does the snowball hold together? The pressure
you apply when you pack the snowball melts a small fraction of the ice.
When you release the pressure, that melted ice re-freezes, holding the
whole ball together. The same thing happens when an ice skater skates:
there's a thin layer of liquid water under the skate blade, formed by the
increased pressure there. When it's extremely cold, snowballs are hard
to make, and it's harder to skate on the ice. That's because the colder
the ice is, the more pressure it takes to melt it. Why it's impossible to have a snowball fight on Mars http://www.aspsky.org/mercury/mercury/9801/snowball.html More Facts about snow and ice http://www.cool-fact.com/archive/1997/07/25.html http://www.cool-fact.com/archive/1998/11/06.html http://www.cool-fact.com/archive/1999/01/14.html
