NOVEMBER

What keeps a bullet on a straight course?

In the Old West a "straight shooter" was an honest person you could rely on. Metaphorically, shooting straight meant that the person was like a bullet's path: true, not crooked. But just what was it that enabled a bullet to travel in a straight line?

The bullets coming out of the first muskets were literally scattershot. The unevenly shaped lead balls bounced against the inside of the barrel as they were launched and could easily veer off. Gunmakers solved the problem by improving the fit between bullet and barrel and by placing spiral grooves inside the barrel to spin the bullet as it emerged.

Spinning, like a gyroscope, corrects irregularities in an object's flight path. Finally, in the mid-19th century, bullets were aerodynamically redesigned. They were made longer, ending in the familiar conical tip which puts the bullet on the straight and narrow.

(Source: READER'S DIGEST HOW IN THE WORLD)

How were Popsicles invented?

Until 1905 the world had no Popsicles. It was in that year that 11-year old Frank Epperson of Oakland, California invented the popular treat by accident.

He had mixed up some powdered soda pop, but he left the cup outside with the stirring stick still in it. That night there was a record frost. When Frank went outside the next morning, there was his cup with the soda pop frozen solid. He grabbed the stick and the frozen pop came out of the cup in one piece. Eighteen years later Epperson started selling "Eppsicles."

The Eppsicle was eventually called the Popsicle, a trademarked name for what is also known as an ice pop. Today they are sold on thin hardwood sticks, and they have evolved into hundreds of varieties including chocolate dipped ice cream pops (Creamsicles), with or without sprinkles.

More about the invention of the Popsicle:
http://more.abcnews.go.com/sections/tech/Geek/geek990624.html

More about popsicles and other frozen treats:
http://www.familyfun.com/content/aug97/object.html
http://www2.mybc.com/aroundtown/food/columns/archives/1999/aug/garber_12.html

More Cool Facts about food:
http://www.cool-fact.com/archive/1997/11/03.html
http://www.cool-fact.com/archive/1998/12/02.html
http://www.cool-fact.com/archive/1999/11/26.html

How did "pipe down" come to mean, "be quiet?"

The tone of this expression puts it somewhere between "please lower your voice" and "shut your mouth!" But the words in it don't place it anywhere that's at all obvious. What pipe? Where? Why? Who's smoking it?

The reality is that pipe down is yet another expression that comes from the days of sailing ships. The "pipe" in question was a whistle used by the boatswain, a petty officer--sort of a sergeant--who supervised a work crew on deck. When he blew "pipe down" his men were free to go below. Once they went below, it was quiet on deck. And that's the condition to which you aspire when you tell someone to pipe down. If they don't respond, throw them overboard.

(Source: WHO PUT THE BUTTER IN BUTTERFLY? by David Feldman)

What's the slowest pulsar discovered so far?

A pulsar is a spinning neutron star that casts a tight beam of electromagnetic energy around the Galaxy like a searchlight. Until recently, it was thought that in order to create the beam of energy a pulsar had to spin at least several times each second. But a newly discovered pulsar, called PSR J2144-3933 spins only once every 8.51 seconds, making it the slowest pulsar known.

Pulsars are thought to generate their energy beams through the reactions of electrons and positrons (anti-electrons) produced by the star's gigantic magnetic field.

But PSR J2144-3933 is not spinning fast enough to make an energy beam by that process, according to the scientists. Its energy source remains unknown, and the scientists continue to watch it carefully, hoping for more clues.

More about PSR J2144-3933:
http://explorezone.com/archives/99_08/26_slow_pulsar.htm
http://www.spaceviews.com/1999/08/29b.html

More Cool Facts about neutron stars:
http://www.cool-fact.com/archive/1998/02/05.html
http://www.cool-fact.com/archive/1998/06/04.html
http://www.cool-fact.com/archive/1998/08/25.html

How are enormously heavy steel ships able to float?

From the way they look in the water, I'd say "with plenty of effort." They appear to defy basic laws of nature. But in fact, they're obeying a law of nature, buoyancy, which Greek mathematician Archimedes reportedly discovered while taking a bath.

The trick in building ships so that they don't go straight to the bottom is to get the shape right. The vessel has to be configured so that it will be buoyant, displacing a volume of water weighing as much as it does. In other words, if an amount of steel equal to that in a giant tanker were rolled into a compact ball and dropped into the sea, bye, bye ball. But if the metal is spread out over a thousand feet, the ship can cross the ocean.

(Source: READER'S DIGEST HOW IN THE WORLD)

Where is the coldest place on Earth?

The coldest natural outdoor temperature ever recorded (as of January, 2000) was at Russia's Vostock Station in Antarctica. In 1997 the temperature there fell to -91 degrees Celsius (-132 degrees F). At this temperature, steel becomes so brittle it shatters easily.

Vostok Station is located in the middle of a vast expanse of uninterrupted ice, on a high plateau about 780 miles (1260 km) from the South Pole. The ice at Vostok is about 3700 meters thick (12,100 feet) and the surface elevation is 3488 meters (11,444 feet).

Vostok Station is not only the coldest place on Earth, it is also one of the driest. Because the air is so cold, it can hold very little moisture. The air's absolute humidity at Vostok is lower than that of the Sahara Desert.

More about Antarctica, by a scientist who spent a year at the South Pole:
http://ast.leeds.ac.uk/haverah/spaseman/index.shtml

More Cool Facts about Antarctica:
http://www.cool-fact.com/archive/1997/07/06.html
http://www.cool-fact.com/archive/1998/08/10.html
http://www.cool-fact.com/archive/1999/03/31.html

Who invented the Internet and why?

Imagine someone absent-mindedly going to check their email one day, then suddenly realizing that it hadn't yet been invented.
Actually it would have been more appropriate if this mythical person had wanted to download Quake or Doom, because it was the U.S. Department of Defense that first ventured into cyberspace.

It began in 1969 with ARPAnet, a small, restricted computer network that allowed scientists doing Pentagon research to communicate. In the early 80's military research was shifted to another network and the National Science Foundation took over the old ARPA technology and opened it to the public. At first, only the techies showed up on line. Gradually schools connected. Then, as PC's proliferated, public online services such as CompuServe were started. The point and click Web, with graphics, arrived in the early 90s.

(Source: THE WORLD ALMANAC AND BOOK OF FACTS)

Where is the largest temperate rain forest?

The largest unbroken temperate rain forest in the world is the Tongass in southeast Alaska. It is 17 million acres of magnificent wilderness with abundant birds, bears, and other life. How wild is it? Surrounded by the Tongass, the city of Juneau (Alaska's capital) is accessible by ferries or by air, but not by roads.

The Tongass was extensively logged until the early 1990s, when the lumber mills began to shut down. Today, almost the entire region is protected from further development or exploitation, and many groups act to further that protection.

Temperate rain forests (those outside the tropics) look different than tropical rain forests. Dominated by coniferous trees, they grow more slowly but have a larger biomass (total mass of living matter) than tropical rain forests.

More about the Tongass:
http://www.fs.fed.us/r10/tongass/
http://www.gorp.com/gorp/resource/US_National_Forest/ak_tonga

Resource pages for protection of the Tongass:
http://www.tongass.com/
http://www.ptialaska.net/~tongass/

More Cool Facts about forests:
http://www.cool-fact.com/archive/1999/04/30.html
http://www.cool-fact.com/archive/1999/08/27.html

Who made the first marbles?

Marbles have been used for games since the times of the Egyptian Pharaohs, when they were made out of fired clay. Clay marbles were also made by Native Americans, who also used round stones and nuts for their games.

The first glass marbles were made in Venice, Italy around 900 AD. Italian marbles were also made out of polished marble and other kinds of stone around the same time. These stone and glass marbles were used throughout Europe for hundreds of years.

Modern glass marbles did not appear until about 1860, when they were made in Germany. Around 1905, machine-made marbles were first sold in the United States, and their higher quality seriously impacted the European handmade marble marketplace. Today, though, the very best marbles are still made by hand, using secret methods.

More about marble history and collecting:
http://www.blocksite.com/mcc/faq.htm

Another Cool Fact about marbles:
http://www.cool-fact.com/archive/1999/09/23.html

Marble is a Cool Word:
http://www.cool-word.com/archive/1999/09/23.html

Does a person's life really flash before them when they're dying?

What might there be about the threat of death that inspires a sudden indulgence in autobiography? Wouldn't the mind be fixed on other things, such as, "How the heck can I get out of here?" Yet so many people have described this phenomenon--
which makes it real enough--that scientists have been compelled to try to explain it.

Two theories have been proposed. The first holds that a threat
as traumatic as that of imminent demise from any cause, not just drowning, automatically triggers the release of memories that one always retains but usually doesn't recall. The other explanation points to hardware breakdown. Cutting the flow of oxygen to the brain makes its electrical impulses go haywire, catapulting long-stored memories into one's consciousness helter skelter. Either way, I prefer to confine my own life review to whatever a glass of Chardonnay might pry from my temporal lobes.

(Source: READER'S DIGEST DID YOU KNOW?)

What's the closest spacecraft fly-by so far?

On July 28, 1999 the spacecraft Deep Space 1 (DS1) passed within ten kilometers (six miles) of a tiny Asteroid called 9969 Braille, in the closest non-impact fly-by to date of a spacecraft past any celestial object.

Moving at a relative speed of 15.5 kilometers per second (nearly 35,000 miles/hour), DS1 zoomed past Braille more than 50 times faster than the speed of a commercial jet, and twice as fast as the Space Shuttle.

Deep Space 1 is part of NASA's New Millennium Program, a group of missions designed to test and refine new space technologies. DS1 tests twelve new inventions, including a revolutionary ion propulsion system and a sophisticated software navigation system.

The official DS1 web site:
http://nmp.jpl.nasa.gov/ds1/

The New Millennium Program:
http://nmp.jpl.nasa.gov/

More Cool Facts about Deep Space 1:
http://www.cool-fact.com/archive/1998/12/08.html
http://www.cool-fact.com/archive/1999/08/06.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 Cool Facts about telescopes and other seeing instruments:
http://www.cool-fact.com/archive/1998/04/13.html
http://www.cool-fact.com/archive/1998/11/17.html
http://www.cool-fact.com/archive/1999/08/03.html

Exactly what was the forbidden fruit in the Garden of Eden?

If the apple industry had hired the best public relations person in history, they never could have gotten the kind of attention they have received for free from the Biblical story of the Garden of Eden and the forbidden fruit. It's bad publicity, you say? Publicity is publicity. The thing to is to be mentioned--often, everywhere.

But where does it say that the fruit was an apple? Not in any Bible I know about. So many people think it was an apple, but
the text never identifies the fruit. Maybe it was a tangelo. (The Koran says it was a banana.)

Come to think of it, maybe the apple industry did get in there early on with a juicy publicity campaign. Planting the seeds, so to speak.

(Source: PANATI'S BROWSER'S BOOK OF BEGINNINGS)

How do time release capsules work?

Time release capsules, invented in the 1940s, hardly compare in importance to penicillin, the greatest medical advance of that decade. Yet the capsules did represent a revolution in terms of comfort and convenience. (Or would you prefer to wake up every hour during the night to pop pills in installments?)

The way the capsules work is amazingly simple. In effect, you are swallowing a group of small medicinal time bombs--close to a thousand of them in some capsules--with "fuses" set for different times. Those fuses are created by the varying thickness' of a wax-like coating over the medication which determines how soon your digestive system can get at the medicine inside each pellet. The thin-skinned ones go to work almost right away, while the ones with the heavier coatings hang around, waiting for that coating to dissolve. All you have to do is swallow the capsule. Bombs away!

(Source: HOW DO THEY DO THAT? by Caroline Sutton)

Why hasn't the Earth's interior cooled after more than 4 billion years?

Wouldn't you think that after 4 billion plus years of letting off steam via volcanoes, geysers, and other geological temper tantrums, Mother Earth would cool it? Yet after all that time it's still over 3,200 degrees F. down below.

The main reason for the retention of all that heat is the superb insulation, plain old rock, that's keeping it in. Another is that the heat process is being fueled by the energy emitted by the decay of radioactive material way down below-- in effect, a battery with one heck of a long life. And in the scheme of things, volcanoes and such release a miniscule amount of the planet's inner heat. They don't dissipate any more of it than your perpetually angry aunt Sadie dispels her enormous reserves of heat every time she blows her stack.

(Source: WHY THINGS ARE & WHY THEY AREN'T by Joel Achenbach)

Where's the largest pipe organ in the world?

Built between 1929 and 1932, the largest pipe organ in the world is the Atlantic City Convention Hall Organ, in Atlantic City, New Jersey, USA. According to the Guinness Book of World Records, it is also the largest and loudest musical instrument ever constructed.

The monster music maker has 336 stops (tuned sets of pipes that form musical voice settings), and is powered by blowers totaling more than 600 horsepower. The exact number of pipes is not known; the quoted figure is 33,112 but some experts estimate the number at more than 32,000.

The main playing console, which is surrounded by art-deco columns with stylized flames on top, boasts seven keyboards and rank upon rank of stop controls. There are six large foot pedals and dozens of small ones. The pipes are located in chambers that fully surround the auditorium, so the audience is completely immersed in the musical experience.

The Atlantic City Convention Hall Organ Society:
http://www.acchos.org/

Much more about pipe organs:
http://nersp.nerdc.ufl.edu/~bodinew/index.html
http://www3.sympatico.ca/billinger/organ/organ.htm

Another Cool Fact about an extreme musical instrument:
http://www.cool-fact.com/archive/1998/06/22.html

What kind of laser makes the cleanest cut?

The kind of laser cutter that causes the smallest amount of damage to the material surrounding the target is the femtosecond laser, developed in 1997 by a team at the Lawrence Livermore Laboratory.

The secret to the clean cuts of the femtosecond laser is the extremely short duration of its light pulses -- 50 to 100 femtoseconds (a femtosecond is one quadrillionth of a second).
Because the pulse of light is so short, it only removes one layer of atoms with each pulse. These atoms are almost instantly vaporized and blown free of the target zone. By the time they are gone, the laser pulse is over and no further heat is added.

The femtosecond laser has applications ranging from cutting steel to performing delicate microsurgery operations. It was originally developed for use in disassembling nuclear weapon components, which must be done very carefully and precisely.

More about the femtosecond laser:
http://www.llnl.gov/str/Stuart.html

A research group in Germany is developing new applications:
http://wwwa.kip.uni-heidelberg.de/AG_Bille/Projekt/femto.html

More Cool Facts about lasers:
http://www.cool-fact.com/archive/1997/10/16.html
http://www.cool-fact.com/archive/1998/11/18.html
http://www.cool-fact.com/archive/2000/03/22.html

Why do we call people who work off-staff "freelancers?"

The cynics among freelancers will tell you that they are called that because many clients expect them to work practically for free. They are also free to do without employee benefits such as vacations and medical coverage. On the other hand, they do get to set their own hours, write off an espresso and a croissant with a friend as a business expense, and work at home in their underwear

The term originated in the Middle Ages to describe a mercenary knight whose lance was for hire. He was free of any attachment to a particular lord and could be employed on a project-by-project basis--assault a castle, rescue a damsel, the usual stuff. Eventually the term was applied to anyone who was paid by the project or the piece.

(Source: A BROWSER'S DICTIONARY by John Ciardi)



FAST FACTS:

The custom of playing tricks on people on April 1 began in France after a new calendar was instituted in the 16th century. Previously, the New Year had been celebrated April 1, but the new calendar switched it to the familiar January 1.
Out of habit, many people continued to observe April 1 as the
beginning of the year. They were known as "April fools," and eventually the custom arose of playing tricks on that day.

The French call victims of April Fools pranks "April fish." Maybe that's because they go for the bait.

(Source: THE WORLD BOOK ENCYCLOPEDIA)

Why does a candle flame have different zones?

Take a close look at a candle flame. How many different zones does it have? From the wick outward and upward, first there is a transparent zone, then usually a blue zone, then a yellow zone, and possibly a short red one. Sometimes there is even a black zone after that one.

The transparent zone nearest the wick is where wax vapor steadily streams off the wick. There isn't enough oxygen in that zone for it to burn, because the steady stream of vapor keeps it out. But something else important happens here: the heat from the burning part of the flame starts breaking up the chains of carbon atoms in the wax. The long chains of carbon atoms immediately condense into extremely tiny particles of soot, which are carried into the main flame.

The blue zone is colored by the burning of a particular kind of molecular fragment called diatomic carbon (C2). The yellow zone is colored by the burning of the soot particles. If not all the soot burns, then the red zone forms from cooling soot particles, and you might even see the black zone which is smoke (large soot particles) in the process of condensing.

A more detailed explanation:
http://www.newton.dep.anl.gov/askasci/chem99/chem99454.htm

More about soot and candle flames:
http://www.fiscorp.net/iaq/rscience.html

More Cool Facts about fire:
http://www.cool-fact.com/archive/1998/12/01.html
http://www.cool-fact.com/archive/1999/09/14.html

What's the world's largest herb?

An herb is a vascular plant (a plant with water-carrying vessels) that does not have woody tissue (stem tissue in which the cells have died but still carry water). The largest herb in the world is the banana plant (Musa sapientum), a crop grown in tropical countries around the world.

Banana plants have leaves up to four meters long (12 feet) that emerge from an underground corm. The bananas are formed in a large bunch called a hand that forms on the end of a sturdy stem. The fruits of domestic bananas do not contain viable seeds; the plants are reproduced by dividing the corm or by growing tiny plantlets in laboratory tissue cultures.

The average American eats 28 pounds (13 kg) of bananas in a year, more than any other fruit. Worldwide, about 60 million tons of bananas are produced each year. An acre of banana plants can produce as much as seven tons of fruit in a year.

More about bananas:
http://www.traidcraft.co.uk/banana1.htm
http://www.fyffes.com/didyouknow.htm
http://www.wellpathways.com/fitness_nutrition/nutrition/5aday/fruits/banana.asp

Did you know bananas can ease muscle cramps?
http://www.cool-fact.com/archive/2000/02/15.html

What human bone serves no known purpose?

Everyone has a bone that serves no purpose we know of. It's the coccyx [KOK-siks], a small triangular bone at the very end of the spine.

Millions of years ago, our distant ancestors had tails that helped them balance while they moved around in the trees, much like today's tailed monkeys. When they moved from the trees out onto the grasslands of Africa, our prehuman ape ancestors began to stand upright, and the tail diminished to a tiny stump, and then to nothing at all. But the bone that was in the tail is still with us, even though there are no muscles attached to it.

Such a left-over of a once-useful organ is called a vestigial [ves-TIJ-yul] organ. Another organ that may be vestigial is the appendix, a small extension of the intestine that may have once helped filter toxins from our food.

Diagram of the spine, showing the coccyx at the end:
http://reality.sgi.com/sambo/Oobe/CyberAnatomy/HTML/coccyx.html

More about the spinal bones, including the coccyx:
http://homepages.which.net/~ks.burrell/f2/spine.htm

More Cool Facts about bones:
http://www.cool-fact.com/archive/1997/02/20.html
http://www.cool-fact.com/archive/1998/04/06.html
http://www.cool-fact.com/archive/1998/08/26.html

Is it true that animals are colorblind?

You may have heard that a bull never literally "sees red" when the bullfighter waves a cape in his face. It's the movement of the cape that provokes. Animals, after all, are colorblind.

Hold on, not so fast. Birds, for instance, have a marked ability to distinguish colors. They need it to spot food, such as berries, on the ground. On the other hand, most creatures of the night--including the ubiquitous house cat--have little sense of color. But they're awfully good at picking up movement.

So the next time someone tells you that all animals are color blind, tell them that it's not such a black and white proposition.

(Source: READER'S DIGEST, DID YOU KNOW?)

FAST FACTS:

Some believe that the idea of a lucky four leaf clover goes back to Adam and Eve. It's said that when Eve was sent from
the Garden of Eden, she took a four leaf clover with her. The clover may have been lucky but it certainly wasn't as practical as the fig leaf.

(Source: THE KID'S FUN-FILLED QUESTION AND ANSWER BOOK)

How was Play-Doh invented?

For more than 40 years kids have been making monsters, dogs, people, and shapeless blobs out of Play-Doh, a curiously aromatic stuff that comes in different colors. Today it's a multi-million dollar product made by Hasbro, but how did it get started?

It happened in Cincinnati, Ohio in the 1950s, and involved a young man named Joe McVicker. McVicker's sister-in-law was a schoolteacher who wanted softer clay for her young students, who were having trouble molding the hard, water-based mineral clay that was used in schools at that time.

McVicker took the request to a biochemist named Tin Liu at his father's soap and chemical company. Starting with a soft, gooey substance used to clean wallpaper, Tin Liu came up with Play-Doh. McVicker marketed the result, and became a millionaire by the time he was 27. No one seems to know what happened to Tin Liu, who seldom gets credit as Play-Doh's actual inventor.

Two slightly different versions of the Play-Doh story:
http://www.yolk.com/magazine/iss1/doh.html
http://www.yippeee.com/what/playdoh.html

Recipes for home-made clay, play-doh, and more:
http://k2.kirtland.cc.mi.us/~balbachl/kidrecip.htm

More Cool Facts about toys and games:
http://www.cool-fact.com/archive/1997/07/05.html
http://www.cool-fact.com/archive/1999/02/11.html
http://www.cool-fact.com/archive/1999/09/23.html

Why do we tell someone who's snooty to get off his or her high horse?

I've known some pretty snooty people who I wouldn't mind seeing fall off a high horse. But this expression just tells them to get off. So what would they be doing mounted on this tall nag in the first place?

If you know anything about horses, you're aware that they come in a pretty wide variety of sizes and shapes. Clydesdales, for examples, are very big, while Shetland Ponies are, by comparison, pretty diminutive. At one time, the size of your horse would have had a lot to do with your social position.
Knights, for instance, high on the social scale, needed big horses to hold them and their equipment. Other high-standing people just liked to sit tall in the saddle, with a little help from their steed. The expression "get off your high horse" thus means to come down from such social pretensions.

(Source: A BROWSER'S DICTIONARY by John Ciardi,)

FAST FACTS:

Your jaw muscle is the most powerful muscle in your body. Of
course it is, with cell phones it's the one that gets the biggest workout.

A skunk can propel its spray about 10 feet, but its stink can go a lot further.

(Source: THE KID'S FUN-FILLED QUESTION AND ANSWER BOOK)

Why do we say that something that has matured has "come to a head?"

Feet get no respect. You go to the head of your class, you're miles ahead of everyone else, and a good glass of beer has a head on it. But don't get it in your head that this particular expression--come to a head--refers directly to your anatomy. Not this time. Not unless you're a vegetable.

The reference is to the maturing of the very down-to-earth cabbage. As far back as the Renaissance, people going to market were anxious to pick up a head or two. Sometimes, though, farmers had to tell their customers that weather conditions had held back the growth of the crop. The still immature plant had not yet fully formed, had not "come to a head." So there you are: reach maturity and they compare you
to a cabbage.

(Source: WHY YOU SAY IT by Webb Garrison)


FAST FACTS:

The English language contains only four words that end in "dous." They are tremendous, stupendous, hazardous...and..and...if I don't tell you the last one that would absolutely horrendous.

(Source: OXFORD ENGLISH DICTIONARY)

What are the oldest seeds that sprouted?

The oldest known viable seeds were found in 1954 in a lemming burrow in Canada's frigid Yukon. The burrow, which was buried in silt and sediment, had been frozen since the last ice age.

The arctic tundra lupine seeds (Lupinus arcticus) were found with lemming remains that were at least 10,000 years old. When they were placed in favorable conditions, several seeds sprouted within 48 hours. One of the plants later bloomed.

Other cases of extremely old seeds that sprouted include a 3400-year-old bean from the tomb of Tutankhamun and water lily seeds that were found with a canoe that had been buried in a bog near Tokyo for more than 3000 years.

A page about the ancient lupine seeds:
http://www.nature.ca/notebooks/english/arclupin.htm

More about Canada's arctic lupine, a beautiful wildflower:
http://rbcm1.rbcm.gov.bc.ca/nh_papers/nativeplants/lupinus.html

More Cool Facts about very old living things:
http://www.cool-fact.com/archive/1997/03/31.html
http://www.cool-fact.com/archive/1997/07/03.html

What country has the most tornadoes?

The country with the most tornadoes is the United States, where about 800 twisters touch down every year. Most of them happen in the central plains states ("Tornado Alley"), where gigantic "supercell" thunderstorms sweep across the landscape, fed by moisture from the Gulf Of Mexico colliding with cooler, dryer air from the Rocky Mountains.

The second place winner for most tornadoes is Australia, where a few hundred form every year. They also happen sometimes in the plains of Asia.

Tornadoes can happen in any country that gets thunderstorms, but they require very special conditions. A heavy layer of cool, dry air must flow above a layer of warm, moist air, and there must be a certain twist to the air currents to start the vortex spinning.

The National Weather Service's page on tornadoes:
http://www.nssl.noaa.gov/NWSTornado/

More Cool Facts about thunderstorms:
http://www.cool-fact.com/archive/1998/01/07.html
http://www.cool-fact.com/archive/1999/07/26.html
http://www.cool-fact.com/archive/1999/10/11.html

How do airline pilots land in a fog?

Carefully! Your plane can't pull over to the side of the road in bad weather, so the pilot had better be able to find the runway. That's where the "instrument landing" you may have heard of comes in.

A bit less than 10 miles from touch down and just under 500 feet altitude, the plane's radar picks up a signal, the outer marker, that orients the pilot toward the runway's glide path. This path is defined by two signals. One keeps the pilot from veering too far to either side, while the other guides the plane down at the correct angle. At a height of 200 feet the middle marker signals the fail-safe point. If the runway lights are still not visible, you're going back up and on to another airport (and wherever that may be, you will still wait an hour for your luggage).

(Source: HOW DO THEY DO THAT? by Caroline Sutton)

FAST FACTS:

The subject of the Mona Lisa, one of history's most famous paintings, was a Florentine merchant's wife. Have you ever noticed that she has no eyebrows? It was customary in Florence in those days to shave them off.

There are three earlier versions of La Giaconda, the painting's real name, underneath the top layer. From an inside source in the Louvre, I have learned that in one of those versions playful painter Leonardo da Vinci actually gave his subject not only eyebrows, but a beard, moustache and sideburns as well.

(Source: 2201 FASCINATING FACTS)