Clipmarks | Rustee's Educational collection

Fool's Mate - Fastest Possible Checkmate

Sat, 06 Sep 2008 02:35:13 GMT

clipped by: Rustee

Clip Source: www.geocities.com

Checkmate! White cannot interpose or move his King. The game is over. Black wins.

Tags: chess, games

The Pigeonhole Principle

Sat, 23 Aug 2008 06:06:45 GMT

clipped by: Rustee
clipper's remarks:

Do any two people in Houston have the same number of hairs on their heads? Sounds tough to answer. Lining people up. Counting their hair follicles.
Let’s take another look at our hair problem. The average head has 150 thousand hair follicles. So we can safely assume there’s no head with more than, say, a million hairs on it.
Now let’s imagine we have a collection of holes labeled zero through a million. We’ll take all the residents of Houston and put them in the holes corresponding to the number of hairs on their heads. But Houston has a population of over two million. So by the pigeonhole principle, at least one hole (and probably many) will contain at least two people. We can be certain that at least two people in Houston have the same number of hairs on their heads. And we haven’t counted anything.

Clip Source: www.uh.edu

The pigeonhole principle is a wonderful mathematical tool because it’s so incredibly simple yet comes in so handy. It takes its name from the following example. Suppose we have ten pigeons but only nine pigeonholes to put them in. Since we have more pigeons than pigeonholes, at least one of the holes must have at least two pigeons in it. That’s it. That’s the pigeonhole principle.

It’s so basic that when it shows up in the solution of a more difficult problem it evokes a smile.

The tricky part is recognizing that the pigeonhole principle can be used, and then figuring out what are the pigeons and what are the holes.

Do you have three different styles of socks mixed up in your dresser? No worries. Just pull out any four socks and you’re sure to have a matching pair. Once again, it’s the pigeonhole principle at work.

Tags: math, ingenuity

Why We Love Our Lawns

Sat, 09 Aug 2008 22:13:31 GMT

clipped by: Rustee
clipper's remarks:

Falk tested his theory by showing various groups worldwide photos of different landscapes, including their own. All groups said they'd prefer to live in savanna-like surroundings, even jungle-dwellers and city folk who'd never seen a savanna or a lawn.

Clip Source: www.dnronline.com

Clip Source: www.gi.alaska.edu

Why are people so willing to work for the doubtful pleasure of living on the best possible approximation of a putting green?

The economics of lawns apparently supports one set of theories about them. These theories, which might be called the sociologists' explanation, center on the history of lawns as status symbols.

It also kept the surrounding terrain cleared so invaders couldn't sneak up on the castle.

By this reasoning, each home is truly a castle, or, at least, has castle-like grounds.

But this doesn't explain the more ancient and multi-cultural preference for lawns.

the view of John Falk of the Smithsonian Institution: it's in our genes.

The generally agreed-upon homelands of humankind lie in the region we call East Africa.

For thousands upon thousands of years, our ancestors wandered this terrain, using trees for shelter and protection, visiting the water holes, and watching for big predators approaching through the grass. Thus, the shorter the grass, the better

Tags: trivia, evolution, culture

The Heart of Monticello

Sat, 02 Aug 2008 06:52:13 GMT

clipped by: Rustee
clipper's remarks:

And Jefferson's cry of pain was swallowed up in a most remarkable act of rational self-expression.
He went back to work on Monticello with the idea that she should come away from royal England, into the lovely American wilderness, and see it.

Clip Source: www.uh.edu

He chose a remote but stunningly beautiful site he called the Little Mountain, Monticello. Three years later he moved in with his new bride, Martha. It was home during the American Revolution. Then Martha died in 1781 with the house still unfinished.

Three years later, Jefferson, still grieving, went to France as foreign minister. And a strange thing happened in Paris.

In 1786 the artist John Trumbull took Jefferson to see the new Grain Exchange building. It was fitted with a great 130-foot iron dome -- a marvelous feat of construction.

There Jefferson met the free-wheeling English miniaturist Richard Cosway and his wife. She was the artist and composer Maria Cosway. In October the Cosways went back to England. By then Jefferson and Maria had been close friends for several months, and his heart had quite taken leave of him.

He never saw Maria again, but he tore the old Monticello apart and created a new thing entirely

The central focus was now a great dome -- the dome of the Grain Exchange.

Clip Source: www.dl.ket.org

Tags: history, thomas jefferson, architecture

Climate of the Carboniferous Period

Sun, 06 Jul 2008 17:11:52 GMT

clipped by: Rustee
clipper's remarks:

Earth's atmosphere today contains about 380 ppm CO2 (0.038%). Compared to former geologic times, our present atmosphere, like the Late Carboniferous atmosphere, is CO2- impoverished!

Understanding Earth's geologic and climate past is important for understanding why our present Earth is the way it is, and what Earth may look like in the future.

Clip Source: www.geocraft.com

Average global temperatures in the Early Carboniferous Period were hot- approximately 20° C (68° F). However, cooling during the Middle Carboniferous reduced average global temperatures to about 12° C (54° F). As shown on the chart below, this is comparable to the average global temperature on Earth today!

Similarly, atmospheric concentrations of carbon dioxide (CO2) in the Early Carboniferous Period were approximately 1500 ppm (parts per million), but by the Middle Carboniferous had declined to about 350 ppm -- comparable to average CO2 concentrations today!

In the last 600 million years of Earth's history only the Carboniferous Period and our present age, the Quaternary Period, have witnessed CO2 levels less than 400 ppm.

To the consternation of global warming proponents, the Late Ordovician Period was also an Ice Age while at the same time CO2 concentrations then were nearly 12 times higher than today-- 4400 ppm.

Tags: global warming, climate change

Shapeshifting Sun

Thu, 03 Jul 2008 04:47:11 GMT

clipped by: Rustee

Clip Source: virtual.finland.fi

Tags: photography

Magnetospheric Audio

Thu, 03 Jul 2008 04:29:59 GMT

clipped by: Rustee

Clip Source: science.nasa.gov

The space around the atmosphere is alive and dynamic, not empty and still. Our planet is connected with our sun with more than light.

Clip Source: science.nasa.gov

About 100 years ago, people in England heard some strange noises on their newly developed telephones.

The people in England listening on their telephones during an aurora similar to that shown, might have heard something like this ...

Very Low Frequency Saucers Audio Clip

Clip Source: science.nasa.gov

The next reports of strange sounds came during World War I.

Here is what the soldiers may have heard....

"Whistlers" Audio

Clip Source: science.nasa.gov

From Voyager 1 we also found "chorus"; one of the first kinds of natural radio waves described by telephone operators at earth.

Jupiter's "Chorus" Audio

Clip Source: science.nasa.gov

When Voyager 2 got to Saturn, it found a similar kind of radio noise.

Voyager 2 Saturn Audio

Clip Source: science.nasa.gov

When Voyager 2 got closer to Saturn, it picked up this signal....

Saturn's "Hiss" Audio

Clip Source: science.nasa.gov

Voyager's Pass through the Rings of Saturn Audio

Tags: science, astronomy, physics, nasa

Reduce, Reuse, Recycle - On a Stellar Scale

Sun, 29 Jun 2008 18:31:58 GMT

clipped by: Rustee
clipper's remarks:

PSR 1257 is too faint to see...It's so tiny that you couldn't even see it from its planets.

Clip Source: stardate.org

Here on Earth, Nature recycles rocks, dead plants and animals, and just about everything else. But out in the universe, it may recycle entire planets.

An example is a system known as PSR 1257+12 -- the first confirmed planets discovered outside our own solar system. The system contains three planets that are roughly comparable to Earth -- fairly small, and probably made of rock.

The original star was a supergiant -- much bigger, heavier, and hotter than the Sun. It lived a short but dazzling life, then blasted itself to bits as a supernova.

The star's core collapsed to form a neutron star -- an object that's several times as massive as the Sun, but no bigger than a city.

When the star exploded, any distant planets might have been hurled away at breakneck speeds. But planets at close range would have been pulverized. So the planets in the system today weren't always there. They probably formed from the debris left over from the blast -- a case of recycling on a gigantic scale.

Tags: science, astronomy

Iroquois Blueprint for the U.S.

Sat, 28 Jun 2008 04:00:40 GMT

clipped by: Rustee
clipper's remarks:

Our constitution has many Iroquois features. Iroquois lawmakers didn't go to war. Civilian and military rule was separate.

The Iroquois had no royalty -- no hereditary rule. Their nations could naturalize new citizens. The League didn't just conquer other nations. It could also admit them to membership.

We didn't adopt the Iroquois unicameral system. They had only one council. Franklin fought for that. Because he lost, we have both the senate and the house.

Franklin also wanted to let soldiers elect their own officers. That's what the Iroquois did. He lost on that one, too.

Still, our constitution is a fine piece of engineering design. We looked at the European kingdoms we'd left behind. And we looked at these people who'd governed themselves so well for so long.

In the end Canassatego and the Iroquois tipped the scales in shaping our way of life. And we can be very glad they did.

Clip Source: www.uh.edu

In 1744 the Iroquois leader Canassatego spoke at the Indian-British assembly in Philadelphia. Dealing with 13 administrations in 13 colonies was impossible, he said. Why didn't we form an umbrella group? Each colony could keep its sovereignty. Yet the 13 could speak to other nations with one voice.

He offered a model. During Europe's Middle Ages, Hiawatha had founded the League of Iroquois Nations. The Mohawks, Onondagas, Senecas, Oneidas, Cayugas, and Tuscaroras formed the League.

Historian Jack Weatherford says few colonists were ready to listen. But one was. Ben Franklin had studied the Indians. Later, he became the Indian Commissioner. As early as 1754 he wanted to try Canassatego's idea. Later, he and others built that idea into our constitution.

Each Iroquois nation ran its internal affairs with a council of elected delegates. They also sent delegates to a grand council. It ran affairs among nations. It was a pure federal system.

Tags: history, government

Margaret Corbin - Soldier for Liberty

Thu, 05 Jun 2008 06:06:44 GMT

clipped by: Rustee
clipper's remarks:

Life was difficult because of her injury, and in 1779 she received aid from the government...the first woman in the United States to receive pension from Congress.
After Congress’s decision, Margaret was included on military rolls until the end of the war. After being discharged, Margaret remained near West Point, known to officials and acquaintances as “Captain Molly”.

In 1926, the Daughters of the American Revolution had Margaret’s remains reburied in the West Point military cemetery, becoming the only Revolutionary War soldier to be buried there.

Clip Source: usinfo.state.gov

Clip Source: en.wikipedia.org

Margaret Corbin was born in West Pennsylvania on November 12, 1751 in what is now Franklin County.

In 1756, when she was five years old, Margaret’s parents were attacked by Native Americans. Her mother was kidnapped and her father was killed.

On November 16, 1776 she and her husband, John Corbin, both from Philadelphia, along with some 600 American soldiers, were defending Fort Washington in northern Manhattan from 4,000 attacking Hessian troops under British command. John and Margaret crewed one of two cannons the defenders possessed.

During an assault by the Hessians, John was killed, leaving his cannon unmanned. Margaret had been with her husband on the battlefield the entire time, and, after witnessing his death, she immediately took his place at the cannon. She fired away until her arm, chest, and jaw were hit by enemy fire. The British ultimately won the Battle of Fort Washington, resulting in the surrender of Margaret and her comrades.

Tags: history, american revolution, military

The Parents of Invention

Mon, 02 Jun 2008 05:33:45 GMT

clipped by: Rustee

Clip Source: www.uh.edu

"Who's the mother of invention?" People often ask me that.

Of course, invention serves necessity. But do you really believe necessity can drive the inventive muse? I have the same problem with profit.

I'll claim flatly that freedom is the nurturing mother of invention.

Invention always flourishes when people are free -- when they enjoy intellectual permissiveness. Every time personal liberty opens up in a society, invention flourishes.

An unfree person goes to great lengths to claim a quiet place in his own head -- a place to be free.

But the primal, driving, seminal, origin of invention has to be pleasure.

If you've once tasted the pleasure of creating something good and new, you'll want to return to the moment at all costs.

People like Edison, Bell, and Einstein kept coming back to that well of life until the day they died.

Make no mistake about it. The parents of invention are pleasure and freedom. And I tell you, they are the finest parents any child could ever claim.

Tags: invention, freedom

Ancient Greek Music Theory - Modes

Sun, 01 Jun 2008 23:36:36 GMT

clipped by: Rustee
clipper's remarks:

The Greeks had developed a complex system of relating particular emotional and spiritual characteristics to certain modes (scales). The names for the various modes derived from the names of Greek tribes and peoples, the temperament and emotions of which were said to be characterized by the unique sound of each mode, which included the Ancient Greek subgroups (Ionians, Dorians, Aeolians), one small region in central Greece (Locris), and certain neighboring (non-Greek) peoples from Asia Minor (Lydia, Phrygia). Thus, Dorian modes were "harsh", Phrygian modes "sensual", and so forth.

Clip Source: en.wikipedia.org

The very word music, itself, comes from the muses, the daughters of Zeus and patron goddesses of creative and intellectual endeavours.

It is important to note that the entire study of such things by the Greeks was less a formula for the production of playable music than it was a mathematical and philosophical description of how the universe, in general, was perceived to be constructed—the stars, the sun, the planets, all vibrating in harmony.

Yet, it is equally true that once formal descriptions of consonant intervals were in place, there followed, rather naturally, descriptions of what notes should be played in succession to be "correct" scales from which "correct" melodies might be formed. These scales were called modes, and they were crucial to the further development of western music.

Clip Source: en.wikipedia.org

Plato and Aristotle describe the modes to which a person listened as molding the person's character.

The effect of modes on character and mood was called the "ethos of music".

Tags: music theory, history, culture

Magnetic Rain

Fri, 23 May 2008 05:46:20 GMT

clipped by: Rustee
clipper's remarks: Texas sized blobs eh? Whoa.

Clip Source: spaceweather.com

MAGNETIC RAIN: There's a rainstorm underway on the sun's eastern limb. You'd better bring your asbestos umbrella, though, because the "droplets" are Texas-sized blobs of hot plasma:

Prominences are clouds of hydrogen held above the surface of the sun by magnetic fields. While this particular cloud appears to be raining like a summer shower on Earth, the true situation is more complicated. Look carefully: Some of the plasma raindrops are falling "up." That's because the motions are controlled by not only gravity but also magnetism, a force of little importance in terrestrial rainstorms. The solar magnetic field is rooted below the sun's visible surface; roiling motions in the body of the sun itself cause magnetic fields high overhead to shift, wriggle, and "rain" in all directions. No wonder prominences are so much fun to watch.

Tags: science, astronomy, sun

How Anti-Matter Propulsion Works

Thu, 22 May 2008 20:03:46 GMT

clipped by: Rustee
clipper's remarks: It's not rocket science...at least rockets as we know them.

So, why haven't we built a matter-antimatter reaction engine? The problem with developing antimatter propulsion is that there is a lack of antimatter existing in the universe.
For now, we will have to create our own antimatter. Luckily, there is technology available to create antimatter through the use of high-energy particle colliders, also called "atom smashers." But these high-energy particle accelerators only produce one or two picograms of antiprotons each year. A picogram is a trillionth of a gram.

It states that anti-matter propulsion is the most energy efficient propulsion. I suspect that will be true as long as the process of making the anti-matter is itself efficient enough to make it feasible.

Clip Source: science.howstuffworks.com

NASA is possibly only a few decades away from developing an antimatter spacecraft that would cut fuel costs to a fraction of what they are today.

Matter-antimatter propulsion will be the most efficient propulsion ever developed, because 100 percent of the mass of the matter and antimatter is converted into energy.

There are three main components to a matter-antimatter engine:

Magnetic storage rings - Antimatter must be separated from normal matter so storage rings with magnetic fields can move the antimatter around the ring until it is needed to create energy.

Feed system - When the spacecraft needs more power, the antimatter will be released to collide with a target of matter, which releases energy.

Magnetic rocket nozzle thruster - Like a particle collider on Earth, a long magnetic nozzle will move the energy created by the matter-antimatter through a thruster.

Approximately 10 grams of antiprotons would be enough fuel to send a manned spacecraft to Mars in one month.

Tags: science, space, nasa

The First American Patent - Turning Ash Into Gold

Thu, 22 May 2008 05:35:23 GMT

clipped by: Rustee
clipper's remarks:

We don't get the potassium salts we need from wood anymore. But for a long time, Hopkins had put us at the center of a great chemical process industry. So our first patent was one of the great American patents after all.

Clip Source: www.uh.edu

The U.S. Patent Office has issued five million patents since it opened in 1790.

A whole lot of chaff surrounds the real nuggets of accomplishment. So what about the first American patent? We might expect to find chaff there, but we don't.

Samuel Hopkins received the first one on July 31st. Both George Washington and Thomas Jefferson signed it. Hopkins had created a new process for making potash.

We derive the word potassium from potash. Potash is an impure form of potassium carbonate. We use it to make soap, glass, fertilizers, and gunpowder. It's a very important substance. It was our first industrial chemical.

During the mid-1700s potash-making became an American cottage industry. We used the burned-out ashes from wood fires. We leeched them in big iron kettles. Then we boiled the liquid

Hopkins used a furnace to reburn ashes. His process greatly improved the yield of potash as well as its purity. For the next 70 years America was the world's main potash producer.

Tags: history, invention