Dec 28, 2013

Heavy Water

Heavy water contains heavy hydrogen, or deuterium, instead of normal hydrogen.  Deuterium is the stable, nonradioactive isotope of hydrogen with atomic weight 2.01363 and symbol D, or 2H. It is commonly called heavy hydrogen because its atomic weight is approximately double that of ordinary hydrogen, but it has identical chemical properties. Deuterium has about twice the atomic weight of normal hydrogen because its nucleus contains a proton and a neutron, instead of just a proton. Hydrogen as it occurs in nature contains approximately 0.02 percent of deuterium. The boiling point of deuterium is -249.49° C (-417.08° F), or 3.28° C (5.90° F) higher than that of ordinary hydrogen. Heavy water (deuterium oxide, D2O) boils at 101.42° C (214.56° F) as compared to 100° C (212° F), the boiling point of ordinary water. It freezes at 3.81° C (38.86° F) as compared to 0° C (32° F) for ordinary water. Its density at room temperature is 10.79 percent greater than that of ordinary water.

Deuterium, which was discovered by the American chemist Harold Urey and his associates in 1932, was the first isotope to be separated in a pure form from an element. Several methods have been used to separate the isotope from natural hydrogen. The two processes that have been most successful have been fractional distillation of water and a catalytic exchange process between hydrogen and water. In the latter system, when water and hydrogen are brought together in the presence of a suitable catalyst, about three times as much deuterium appears in the water as in hydrogen. Deuterium has also been concentrated by electrolysis, centrifuging, and fractional distillation of liquid hydrogen.

Dec 21, 2013

Book of the Dead

The name generally given to a large collection of funerary texts of various dates, containing magical formulas, hymns, and prayers believed by the ancient Egyptians to guide and protect the soul (Ka) in its journey into the region of the dead (Amenti). Egyptians believed that the knowledge of these texts enabled the soul to ward off demons attempting to impede its progress, and to pass the tests set by the 42 judges in the hall of Osiris, god of the underworld. These texts also indicated that happiness in the afterlife was dependent on the deceased's having led a virtuous life on earth. The earliest religious (funerary) texts known were found cut in hieroglyphs on the walls inside the pyramids of the kings of the 5th and 6th Dynasties of the Old Kingdom; these became known as the Pyramid Texts. A famous example is found in the pyramid of Unas (reigned about 2356-2323 BC), the last king of the 5th Dynasty. In the first Intermediate Period and in the Middle Kingdom private individuals had these texts painted on coffins, from which the alternate name Coffin Texts is derived. By the 18th Dynasty the texts were inscribed on papyri placed in the mummy case; these papyri were frequently from 15 to 30 m (50 to 100 ft) long and illustrated in color.

Dec 14, 2013

Solar-terrestrial effects

Besides providing light and heat, the Sun affects the Earth through its ultraviolet radiation, the steady stream of the solar wind, and the particle storms of great flares. The near-ultraviolet radiation from the Sun produces the ozone layer, which in turn shields the planet from such radiation. The soft (long-wavelength) X rays from the solar corona produce those layers of the ionosphere that make short-wave radio communication possible. The harder (shorter-wavelength) X-ray pulses from flares ionize the lowest ionospheric layer, producing radio fadeouts. The Earth's rotating magnetic field is strong enough to block the solar wind, forming the magnetosphere, around which the solar particles and fields flow. On the side opposite to the Sun, the field lines stretch out in a structure called the magnetotail. When shocks arrive in the solar wind, a short, sharp increase in the field of the Earth is produced. When the interplanetary field switches to a direction opposite the Earth's field, or when big clouds of particles enter it, the fields in the magnetotail reconnect and energy is released, producing the aurora borealis (northern lights). Big flares or coronal mass ejections bring clouds of energetic particles that form a ring current around the magnetosphere, which produces sharp fluctuations in the Earth's field called geomagnetic storms. These phenomena disturb radio communication and produce voltage surges in long-distance transmission lines and other long conductors.

Dec 6, 2013

Population growth in Paris and New York

It is estimated that in 1800 the population of Paris was about 550,000 and New York’s about 60,000. In 1931, however, these numbers increased to 2,800,000 for Paris and 7,400,000 for New York. (Adapted from 'The Timetables of History', by Bernard Grun, based upon Werner Stein’s Kulturfahrplan)

Dec 1, 2013

The Splice of Life

Dr. James Watson, left, and Dr. Francis Crick with their 
Nobel Prize-winning model of the DNA molecule
Genetic engineering is the process that inserts genes from one living organism into the cells of another, thereby custom-tailoring them to do work they weren't designed for. For example, thanks to genetic engineering, or recombinant-DNA technique, millions of bacteria are kept busy churning out precious human insulin. Scientists built the micro-factories by slipping the human gene responsible for the creation of insulin into E. coli, a mild-mannered bacterium found in our intestinal tract. So far, genetic engineering has been most successful with microorganisms, plants, mice (whose immune systems have been made to mimic those of human beings), and-Stephen King, take note -- livestock: pigs that gain weight faster, cows that give more milk. Science is still working on the problem of getting genetically altered DNA back into a human cell and, we're told, isn't even close to a solution. Someday, however, we may be able to replace or repair bad genes, like the ones responsible for such diseases as cystic fibrosis, sickle-cell anemia, and perhaps even cancer.

Nov 25, 2013

Strategic minerals

Strategic minerals are minerals essential to the national defense -- the supply of which a country uses but cannot produce itself. 33% to 50% of the 80 minerals used by industry could be classed as strategic minerals. Wealthy countries, such as the United States, stockpile these minerals to avoid any crippling effect on their economy or military strength if political circumstances were to cut off their supplies. The United States, for instance, stockpiles bauxite (14.5 million tons), manganese (2.2 million tons), chromium (1.8 million tons), tin (185,000 tons), cobalt (19,000 tons), tantalum (635 tons), palladium (1.25 million troy ounces), and platinum (453,000 troy ounces). (The Handy Science Answer Book, compiled by the Science and Technology department of the Carnegie Library of Pittsburgh)

Nov 20, 2013

Electron Microscope

A microscope that uses electrons instead of visible light to produce highly magnified images of objects. Scientists use electron microscopes in many different fields of research, including medicine, biology, chemistry, metallurgy, entomology (the study of insects), and physics. Since its introduction in the 1930s, the electron microscope has revolutionized the study of microscopic structures and surfaces. See also Microscope.

Microscopes can only resolve structures that are larger than the length of the waves (such as light waves) reflecting off of them. Electron microscopes are able to obtain much higher powers of magnification than standard visible light microscopes because electrons have much shorter wavelengths associated with them than light waves. The highest magnification achievable with light microscopes is about 2,000X (times); modern electron microscopes can achieve magnifications approaching 1,000,000X.

Their invention
The invention of the electron microscope was made possible by a number of theoretical and experimental advances in physics and engineering. The main concept on which the electron microscope is founded—that electrons have a wavelike nature—was hypothesized by French physicist Prince Louis Victor de Broglie in 1923 (see Quantum Theory). In 1927, de Broglie’s hypothesis was experimentally verified by American physicists Clinton J. Davisson and Lester H. Germer, and independently by English physicist George Paget Thomson. In 1932 German engineers Max Knoll and Ernst Ruska built the first transmission electron microscope. In 1938 Ruska and German engineer Bodo von Borries built the first model of the commercial TEM for the Siemens-Halske Company in Berlin, Germany. The English engineer Sir Charles Oatley invented the SEM in its present form in 1952.

Nov 14, 2013

intra-abdominal fat

what is it?  Fat packed deep in the abdomen, in and around your internal organs. Women with waists over 35 inches and men with waists over 40 inches are likely to have it. (For people of Asian descent, risk rises with measurements over 31.5 inches for women and 37.5 for men.) A large waist is dangerous even if your body weight is within the " healthy" range for your height. To measure your waist, wrap a tape measure snugly around your midsection at about belly-button height.

What causes it? Too many hamburgers, too much TV, and too much of all those other activities that keep you sitting down, like working and driving. In other words, a diet high in calories and a life devoid of exercise. Chronic stress plays a role, too, especially for women, since the stress hormone cortisol directs your body to store more fat in your abdomen.

1. A high-calorie diet, lack of exercise, and chronic stress conspire to prompt your body to store dangerous fat around your liver, pancreas, and other internal organs.

2. Intra-abdominal fat pumps free fatty acids and inflammatory compounds into the portal vein, the "superhighway" that delivers blood from your lower abdomen to the liver, pancreas, and other internal organs.

3. An influx of free fatty acids causes your liver to produce more “bad” LDL cholesterol, less “good” HDL cholesterol, more blood sugar, and less adiponectin, a hormone that regulates the use of blood sugar and keeps appetite in check. The result: Your risk of heart disease and diabetes rises.

4. The inflammatory compounds secreted by fat cells encourage the growth of plaque inside artery walls, boost blood pressure, and make blood more likely to clot - a recipe for a heart attack. They also make cells resistant to insulin, which in turn contributes to diseases from Alzheimer's to cancer.

Nov 3, 2013

Breast Cancer – What we Know

The incidence of breast cancer in the United States began climbing steadily in the early 1970s, and is now the highest ever seen in human history. Nearly 50,000 American women die of the disease every year. In the face of this tragedy, a great deal of attention has been given to genetics, but the presence of the breast cancer susceptibility gene, called BRCA-1, only accounts for at most 5 percent of breast cancers.

Exercise is very important to breast cancer risk. In fact, women who exercise (walk) for four hours per week lower their risk by 33 percent. And women who exercise more than that lower their risk even further. [29]

But diet, it turns out, is even more important. . .

What We Know

Death rate from breast cancer in the United States: 22.4 (per 100,000)

Death rate from breast cancer in Japan: 6.3 (per 100,000)

Death rate from breast cancer in China: 4.6 (per 100,000)

Primary reasons for difference: People in China and Japan eat more fruits and vegetables and less animal products, weigh less, drink less alcohol, and get more exercise than people in the United States.

Oct 26, 2013

The rainiest place on Earth

The wettest place in the world is Tutunendo, Colombia, with an average annual rainfall of 463.4 inches (1177 centimeters) per year. The place that has the most rainy days per year is Mount Waialeale (means ‘rippling water’) on Kauai, Hawaii. It has up to 350 rainy days annually.

In contrast the longest rainless period in the world was from October, 1903, to January, 1918, at Arica, Chile - a period of 14 years. In the United States the longest dry spell was 767 days at Bagdad, California, from October 3, 1912, to November 8, 1914. (The Handy Science Answer Book, compiled by the Science and Technology department of the Carnegie Library of Pittsburgh)

Oct 17, 2013

Fungal Diseases of Plants

Most types of plant-related diseases are caused by fungi. The leaves of this plant have been infected by tar-spot fungus. Fungi can infect all parts of the plant including leaves, stems, flowers, roots, and fruit. The physical manifestations of fungal diseases of plants include wilting, club root, root rot, wood rot, cankers, various types of mildews, blights, lesions, and leaf spots. The effects of fungal diseases can be devastating as evidenced by the potato blight that destroyed the Irish potato harvest of 1845 and caused a widespread famine in Ireland. (Encarta Encyclopedia) 

Oct 16, 2013

Geometry

Geometry is a branch of mathematics that deals with shapes and sizes. Geometry may be thought of as the science of space. Just as arithmetic deals with experiences that involve counting, so geometry describes and relates experiences that involve space. Basic geometry allows us to determine properties such as the areas and perimeters of two-dimensional shapes and the surface areas and volumes of three-dimensional shapes. People use formulas derived from geometry in everyday life for tasks such as figuring how much paint they will need to cover the walls of a house or calculating the amount of water a fish tank holds.

Geometry combines simple conceptual building blocks to construct complex logical structures. These building blocks include undefined terms, defined terms, and postulates. Combining these components creates chains of reasoning that support conclusions called theorems.

Undefined terms
Some concepts central to geometry are not defined in terms of simpler concepts. The most familiar of these undefined terms are point, line, and plane.

Oct 15, 2013

What Matter Is Made Of

The best analogy for how we are coming to understand matter is the peeling of an onion. We peel off one layer and penetrate to a deeper one, only to discover that there is yet another to work on. The first layer was peeled off our onion in 1805, when British chemist John Dalton published the modern atomic theory of matter. He showed that the enormous variety of substances that surround us is made up of only a few different chemical elements, each of which has its own type of atom. In the early twentieth century the second layer was peeled off when the structure of the atom was revealed. All of the different kinds of atoms, it was argued, were made up of only three kinds of elementary particles – protons and neutrons in the nucleus and electrons orbiting the nucleus; this picture of the atom would become more or less standard. For a while, its inherent simplicity seemed to be clouded when it was found that there were not just two types of particles inside the nucleus, but hundreds. Most of these appeared and disappeared too quickly to be seen, but they could be produced independently in accelerators.

In the mid-1960s, yet another layer was peeled off. It was pointed out that the myriad elementary particles are actually made up of a small number of still more basic entities called quarks. Quarks are held together by particles called gluons -- they're the Elmer's that keeps the three quarks of a proton or neutron together. Scientists believe that these particles derive from an even more basic form of matter called quark-gluon plasma, a primordial soup that made up the universe ten millionths of a second after the Big Bang. As things cooled down, this liquid went through "hadronization," hardening into protons and neutrons, which in turn coalesced first into nuclei, then into atoms. After that, the atoms came together to form molecules, which eventually transformed into you, this book, and the easy chair you're sitting in. At least, that's the theory. (‘An Incomplete Education’, by Judy Jones and William Wilson)

Oct 14, 2013

What on Earth? – a helping hand

Not all inventions change our lives, some just make us scratch our heads.

For all those waiters rushed off their feet, Philip Garner (U.S.) has invented this helping hand. Although unable to snap fingers for the busboy, it is ambidextrous. (‘Inventions and Discoveries’)

Oct 13, 2013

Human beings are virtually identical to one another at the level of genes

In our own genetic profile, believe it or not, scientific evidence indicates that we humans share 99.4 percent of our total DNA sequences with the chimpanzees. This doesn’t mean, of course, that humans are direct descendants from our tree-swinging friends, but it does emphasize that the genius of our molecular code is supported by eons of nature’s greatest evolutionary effort. Our human code was not a random act, at least not in its entirety, but rather is better constructed as nature’s ever-evolving quest for a body of genetic perfection.

As members of the same human species, you and I share all but 0.01 percent (1/100th of 1 percent) of identical genetic sequences. So biologically, as species, you and I are virtually identical to one another at the level of genes (99.99 percent). Looking around at the diversity within our human race, it is obvious that 0.01 percent accounts for a significant difference in how we look, think and behave. (‘My Stroke of Insight’, by Jill Bolte Taylor, Ph.D.)

Oct 12, 2013

Viruses are not considered living organisms

Because they are unable to accomplish life's processes by themselves, viruses are not considered living organisms. They are able to metabolize and reproduce only when they are within living cells. Thus, all viruses are parasites, and many of them cause disease.

Much smaller than the smallest bacteria, most viruses consist only of a strand or two of a nucleic acid – DNA or RNA - wrapped in a protein coat. Some also have a lipid envelope outside the coat. A virus reproduces and spreads because once its nucleic acid is inside a cell, the virus uses the cell's own DNA to produce additional copies of itself. (‘The New York Times Guide to Essential Knowledge’)

Oct 11, 2013

Fur and feathers for protection … and

Mammals have fur and birds have feathers for protection. What covers butterflies and moths?
Answer: Butterflies and moths are covered with colored scales. (Science Challenge, by E. John De Waard and Nancy De Waard)


Oct 10, 2013

The Origin of Language

The use of language is one of the key characteristics that distinguish Homo sapiens from other primates. Because no direct evidence of language exists in the fossil record, researchers have had a difficult time inferring its development. Fortunately, the evolutionary history of the human brain and throat offers some insight.

The human brain plays a vital role in the production and comprehension of language; therefore, the emergence of language capabilities should be reflected somehow in changes to the brain's structure. If this is true, the fossil record can help. Although brain tissue doesn't fossilize, surviving crania can be used to make endocasts, which reveal the shape of the brain that the cranium being cast once held. Because studies of modern human brains have identified the areas where speech production and language comprehension take place, researchers using endocasts can trace the development of these areas over time.

Differences observed in the throat anatomies of modern humans and primates have also aided researches in making inferences about the development of language capabilities. The larynx, for example, occupies a lower position in the human throat than it does in the throats of other primates. This arrangement makes possible the large human pharynx, which produces the relatively wide variety of sounds used in human speech. There is, however, a strong disadvantage to this arrangement: a greatly increased risk of choking while eating or drinking. Therefore, language must have been a strongly advantageous trait; otherwise, the increased incidence of choking would have ensured its elimination through the process of natural selection.

Oct 9, 2013

It takes less energy to be a healthy person than to be a sick one

How would you experience optimal efficiency of your healing system? Very likely you would not be aware of it, because we tend to pay little attention to our health when it is good. You would recover speedily from illness and heal from injuries uneventfully. Ordinary stresses of everyday life might annoy you but would not derange your digestion or blood pressure. Sleep would be restful, sex enjoyable. Aging of your body would occur gradually, allowing you to moderate your activity appropriately and live out a normal life span without undue discomfort. You would not contract heart disease or cancer in middle age, be crippled by arthritis in later life, or lose your mind to premature senility.

This scenario is realistic and, I think, worth working for. Actually, the body wants to be healthy, because health represents efficient operation of all of its systems. A useful analogy is the engine of a far. When all components are doing what they should be doing in just the right way, efficiency is maximal, and operation is quiet, producing a "contented" purr that you rarely notice. An engine that calls attention to itself by sounding noisy and rough, hocking, and expelling black smoke is not efficient. Since efficiency is the ratio of work done to energy supplied, the sick engine is working harder to accomplish less. In a similar way it takes less energy to be a healthy person than to be a sick one, and just as a driver may not pay attention to the sound of a well-running engine, people may not be aware of the condition of good health until it breaks down. A program to boost the efficiency of the healing system will not necessarily produce immediately noticeable changes. It is a long-term investment in the future of the body. (Andrew Weil, M.D., ‘Spontaneous Healing’)

Oct 8, 2013

“Wise Women” - their contributions to health and healing

Most medical histories chronicle great discoveries by great men, from Hippocrates, the father of medicine, to Alexander Fleming, who discovered penicillin. Their contributions should not be underestimated, but from ancient times down to the present day, a relatively small number of male physicians have made the great discoveries and ministered to the kings and princes, while an enormous number of women herbalists have taken care of everyone else.

Women healers have gone by many names: midwives, wise women, green women, witches, old wives, and nurses. Most physicians have never taken women's folk healing very seriously, and scientists often dismiss folk wisdom as "old wives' tales."

But the fact is, medically untrained women still provide most of the world's primary care. Even in the United States, most people view physicians as the health-care choice of last resort. The medical profession promotes the idea that family doctors are our "primary providers," but studies show that before people call health professionals, about 90 percent consult a friend or family member, and those "health advisers" are overwhelmingly women.

Not only that, women have always been the primary consumers of health care. Today women account for an estimated two-thirds of all physician visits and three-quarters of all prescriptions. It's no coincidence many herbs were used historically to calm the womb, trigger menstruation, induce abortion, promote or dry up mothers' milk, and treat infant colic and infectious diarrhea (still a leading cause of infant death in the Third World). These were the daily concerns women patients brought to their women healers.

Oct 7, 2013

The original use of the word “chaos”

In Greek mythology, Chaos was the primal void that gave birth to Gaea (Earth), Tartarus (Infernal Regions), Eros (Love), Erebus (Darkness), and Nyx (Night). (The Book of Answers, by Barbara Berliner)

Oct 6, 2013

On the back of the US $1 bill, what do the words “Annuit Coeptis” mean?

The motto above the eye on the dollar bill means, ''He [God] Favored Our Undertakings." The eye represents the all-seeing deity. The pyramid symbolizes strength; it is unfinished to suggest the work ahead. (The Book of Answers, by Barbara Berliner)

Oct 5, 2013

How Tuesday got its name

The Romans named the third day of the week dies Martis, for Mars, the god of war. It is still known as mardi in French and as martes in Spanish. The Germanic people used the name of their own war god, Tiu -- giving us the name Tuesday.

A few Tuesdays have special importance. The Tuesday after the first Monday in November is Election Day in the United States. People go to the polls to choose the officials who will run the government.

In the Christian calendar, Shrove Tuesday comes right before Lent, -- the 40-day period of prayer and fasting that leads up to Easter. It's -- the last chance for people to eat, drink, and make merry. In days gone by, people tried to use up all the butter and other fats they had on this day because they would have to give up fats during Lent. Rich, buttery foods became a Shrove Tuesday tradition. So this day is also known as Pancake Tuesday, and as Fat Tuesday (or Mardi Gras, in French).

Today some cities still hold Mardi Gras parades and festivals. The Mardi Gras celebration in New Orleans is one of the most famous. But most Tuesdays are just ordinary days. And Tuesdays of the past were pretty dull: Just as Monday was washday, Tuesday was ironing day. (Grolier New Book of Knowledge Encyclopedia)

Oct 4, 2013

Diet and High Blood Pressure

  • Incidence of high blood pressure in meat eaters compared to vegetarians: Nearly triple
  • Incidence of very high blood pressure in meat eaters compared to vegetarians: 13 times higher
  • Patients with high blood pressure who achieve substantial improvement by switching to a vegetarian diet: 30-75 percent
  • What patients are typically told when prescribed medications for high blood pressure: "You’ll probably need to take these for the rest of your life."
  • Patients with high blood pressure who are able to completely discontinue use of medications after adopting a low-sodium, low-fat, high-fiber vegetarian diet: 58 percent
  • Incidence of high blood pressure among senior citizens in United States: More than 50 percent
  • Incidence of high blood pressure among senior citizens in countries eating traditional low-fat plant based diets: Virtually none (‘The Food Revolution: how your diet can help save your life and our world’, by John Robbins)

Oct 3, 2013

The actual shape of a raindrop

Although a raindrop has been illustrated as being pear-shaped or tear-shaped, high-speed photographs reveal that a large raindrop has a spherical shape with a hole not quite through it (giving it a doughnut-like shape). Water surface tension pulls the drop into this shape. As a drop larger than 0.08 inches (2 millimeters) in diameter falls, it will become distorted. Air pressure flattens its bottom and its sides bulge. If it becomes larger than 0.25 inches (6.4 millimeters) across, it will keep spreading crosswise as it falls and will bulge more at its sides, while at the same time, its middle will thin into a bow-tie shape. Eventually in its path downward, it will divide into two smaller spherical drops. (The Handy Science Answer Book, compiled by the Science and Technology department of the Carnegie Library of Pittsburgh)

Oct 2, 2013

Naming hurricanes and tropical storms

Since 1950, hurricane names are officially selected from library sources and are decided during the international meetings of the World Meteorological Organization (WHO). The names are chosen to reflect the cultures and languages found in the Atlantic, Caribbean, and Hawaiian regions. The National Hurricane Center near Miami, Florida, selects the name from one of the six listings for Region 4 (Atlantic and Caribbean area) when a tropical storm with rotary action and wind speeds above 39 miles (62 kilometers) per hour develops. Letters Q, U, X, Y, and Z are not included because of the scarcity of names beginning with those letters. Once a storm has done great damage, its name is retired from the six-year list cycle. (The Handy Science Answer Book, compiled by the Science and Technology department of the Carnegie Library of Pittsburgh)

Oct 1, 2013

Is Chicago the windiest city in the US?

In 1990 Chicago ranked 21st in the list of 68 windy cities with an average wind speed of 10.3 miles (16.6 kilometers) per hour. Cheyenne, Wyoming, with an average wind speed of 12.9 miles ( 20.8 kilometers) per hour, ranks number one, closely followed by Great Falls, Montana, with an average wind speed of 12.8 miles (20.6 kilometers) per hour. The highest surface wind ever recorded was on Mount Washington, New Hampshire, at an elevation of 6288 feet (1.9 kilometers). On April 12, 1934 its wind was 231 miles (371.7 kilometers) per hour and its average wind speed was 35 miles (56.3 kilometers) per hour. (The Handy Science Answer Book, compiled by the Science and Technology department of the Carnegie Library of Pittsburgh)

Sep 30, 2013

How hot is lightning?

The temperature of the air around a bolt of lightning is about 54,000 Fahrenheit (30,000 Celsius), which is six times hotter than the surface of the sun, yet many times people survive a bolt of lightning. American park ranger Roy Sullivan was hit by lightning seven times between 1942 and 1977. In cloud-to-ground lightning, its energy seeks the shortest route to Earth, which could be through a person's shoulder, down the side of the body through the leg to the ground. As long as the lightning does not pass across the heart or spinal column, the victim usually does not die. (The Handy Science Answer Book, compiled by the Science and Technology department of the Carnegie Library of Pittsburgh)

Sep 29, 2013

The first discovery of the harmful effects of cholesterol

Some of the first evidence indicating that atherosclerosis was not simply a consequence of growing old but was rooted in our dietary intake of saturated fat and cholesterol came inadvertently from the Korean War. Soldiers who had been killed were autopsied, and medical researchers were stunned by what they found. More than 77 percent of the American soldiers had blood vessels that were already narrowed by atherosclerotic deposits, while the arteries-of the equally young soldiers of the opposing forces showed no similar damage.

At the time, it was thought that the pronounced differences in the conditions of the soldiers' arteries might be more a consequence of genetic predisposition than of their differing diet-styles. But this idea became quickly untenable when a large group of Korean soldiers were put on the U.S. Army diet. They rapidly developed significant increases in their blood cholesterol levels, an unmistakable sign of developing atherosclerosis.

Traditional nutritionists had thought highly of meat, dairy products, and eggs ever since the early animal experiments that showed rats grew faster on animal protein. As well, the first vitamin ever discovered, vitamin A, had originally been isolated from butterfat, which also added to the aura of supremacy these foods enjoyed.

Sep 27, 2013

Electromagnetic force

It is this force that links atoms and molecules to form ordinary solid bodies. Thus, if your elbow doesn't sink into the wood of your desk while you are writing, it is because the electrons in the atoms of your desk and of your elbow push against each other by means of electromagnetic interaction.

The relationship between electricity and magnetism was discovered in 1820 by Christian Oersted (Denmark) in an experiment during which he noticed that a magnetic needle was deflected by an electric current. Andre Marie Ampere (France) later generalized these observations, but it was James Clerk Maxwell (Great Britain) who, in 1864, formulated the general laws of electromagnetism and showed that light was nothing but an electromagnetic wave.

Since the 1930s a number of physicists such as P.A.M. Dirac (Great Britain) and Richard Feynman and Julian Schwinger (both U.S.) have developed the modem theory of electromagnetic interaction between electrons (with the exchange of photons). (‘Inventions and Discoveries’)

Sep 26, 2013

First time speed of light was measured

The astronomer Jean Picard (France, 1620-82) of the Observatoire de Paris -- who was the first to measure the earth's diameter precisely -- had a young Dane, Olaus Romer, as his assistant. The latter carried out observations of the four large satellites of Jupiter discovered by Galileo some 70 years earlier. He measured the intervals of time between the successive eclipses of the satellites by Jupiter and noted that these were regularly shorter or longer depending on whether Jupiter and the earth were closer together or further apart in their respective orbits around the sun.

Romer understood that this phenomenon was due to delays in the light from Jupiter reaching earth. He then calculated that, to explain all these observations, light traveled at a speed of 186,400 miles per second. At last, after 2,000 years of controversy, it was established that light did not travel instantaneously, but has a finite and measurable speed. (‘Inventions and Discoveries’)

Sep 25, 2013

Synergy

In medicine, synergy is the "cooperative" action of two or more drugs, muscles, or organs. The term is applied especially to drugs whose combined action is more powerful than their simple effects added together.

If used in a business application, synergy means that teamwork will produce an overall better result than if each person within the group were working toward the same goal individually. However, the concept of group cohesion needs to be considered. Group cohesion is that property that is inferred from the number and strength of mutual positive attitudes among members of the group. As the group becomes more cohesive, its functioning is affected in a number of ways. First, the interactions and communication between members increase. Common goals, interests and small size all contribute to this. In addition, group member satisfaction increases as the group provides friendship and support against outside threats.

There are negative aspects of group cohesion that have an effect on group decision-making and hence on group effectiveness. There are two issues arising. The risky shift phenomenon is the tendency of a group to make decisions that are riskier than those that the group would have recommended individually. Group Polarisation is when individuals in a group begin by taking a moderate stance on an issue regarding a common value and, after having discussed it, end up taking a more extreme stance.

A second, potential negative consequence of group cohesion is group think. Group think is a mode of thinking that people engage in when they are deeply involved in cohesive group, when the members' striving for unanimity overrides their motivation to appraise realistically the alternative courses of action. (From Wikipedia and Encarta Encyclopedia)

Sep 24, 2013

Temperature Scales

Five different temperature scales are in use today:
(1) the Celsius scale, known also as the Centigrade scale,
(2) the Fahrenheit scale,
(3) the Kelvin scale,
(4) the Rankine scale, and
(5) the international thermodynamic temperature scale.

The Celsius scale, with a freezing point of 0° C and a boiling point of 100° C, is widely used throughout the world, particularly for scientific work, although it was superseded officially in 1950 by the international temperature scale. In the Fahrenheit scale, used in English-speaking countries for purposes other than scientific work and based on the mercury thermometer, the freezing point of water is defined as 32° F and the boiling point as 212° F (see Mercury). In the Kelvin scale, the most commonly used thermodynamic temperature scale, zero is defined as the absolute zero of temperature, that is, -273.15° C, or -459.67° F. Another scale employing absolute zero as its lowest point is the Rankine scale, in which each degree of temperature is equivalent to one degree on the Fahrenheit scale. The freezing point of water on the Rankine scale is 492° R, and the boiling point is 672° R.

In 1933 scientists of 31 nations adopted a new international temperature scale with additional fixed temperature points, based on the Kelvin scale and thermodynamic principles. The international scale is based on the property of electrical resistivity, with platinum wire as the standard for temperature between -190° and 660° C. Above 660° C, to the melting point of gold, 1063° C, a standard thermocouple, which is a device that measures temperature by the amount of voltage produced between two wires of different metals, is used; beyond this point temperatures are measured by the so-called optical pyrometer, which uses the intensity of light of a wavelength emitted by a hot body for the purpose. (Encarta Encyclopedia)

Sep 23, 2013

Tracing ancient usage of herbs by various cultures

Herbal trial and error becomes even more remarkable when we consider that cultures separated by thousands of miles arrived at similar uses for many healing herbs, apparently independently.

Herbal healing includes four major traditions: Chinese, Ayurvedic (in India), European (including Egyptian), and American Indian. Until the 15th century, Old World cultures were isolated from the Americas. Nonetheless, Old and New World herbalists used many herbs similarly.

Angelica and licorice: Asians, Europeans, and Native Americans all used these herbs to treat respiratory ailments.

Hop and the mints: All the ancient herbal traditions used these herbs as stomach soothers.

Blackberry and raspberry: These two popular herbs have been used around the world to treat diarrhea.

Uva ursi: Asians, Europeans, and Native Americans all discovered this herb's diuretic properties.

White willow: All the herbal traditions used this herb to treat pain and inflammations.

During the 19th century, chemists used this "herbal convergence" to point them to the plants that provided extracts for the first pharmaceuticals. According to a report published in the journal “Science”, of the 121 prescription drugs derived from higher plants, about 74 percent came to drug companies' attention because of their use in traditional herbal healing. (‘The Healing Herbs’, the ultimate guide to the creative power of Nature’s medicine’, by Michael Castleman) 

Sep 22, 2013

Fission and Fusion

They're both nuclear reactions (i.e., they change the structure of an atomic nucleus) and they both represent what happens when Einstein's famous E = mc(squared)  is acted out. In fission, which is behind atomic bombs, nuclear reactors, and radioactivity, the nucleus of a big uranium atom is split into smaller parts when struck by a free neutron. Uranium is the fuel of choice because it "splinters" readily, releasing two or three more neutrons, which in turn strike and splinter neighboring uranium nuclei in a chain reaction. The result: energy; also, Chernobyl.

In fusion, which is behind starlight, sunshine, and the hydrogen (aka. thermonuclear) bomb, and which scientists hope someday to adapt to nuclear-energy production, the nuclei of two little hydrogen atoms are joined together, or fused, at temperatures approaching 50,000,000 Celsius, to form a single, heavy helium nucleus, ejecting high-speed neutrons (and impressively little pollution) in the process. In both fission and fusion, the atoms resulting from the splitting and the joining, respectively, weigh slightly less than the ones that went into the process. It's this difference in mass that has been converted into energy.

So why not forget dangerous, dirty fission and get behind controllable, clean fusion? Because fusion, while it works nicely on the sun, requires temperatures higher than we've in general been able to achieve here on earth except, so far, in the hydrogen bomb, which is triggered by fission -- in the form of an atomic bomb -- at its core anyway. It's true that in late 1993 an experimental fusion reactor at Princeton produced a few megawatts of power for a fraction of a second; while doing so, though, it used up more power than it produced. Nevertheless, a number of countries, including Japan, China, the United States, Russia, and members of the European Union [later joined by India and South Korea] started collaborating on an International Thermonuclear Experimental Reactor (ITER).

Sep 21, 2013

Sep 20, 2013

Holograms

The hologram (from the Greek “holos”, whole, and “gram”, something written) is a three-dimensional photograph using the interference produced by the superimposition of two laser beams. Dennis Gabor (Great Britain, b. Hungary) discovered the principle of holography in 1948 in the course of his research into electronic microscopy. But it was not until the discovery of the laser that practical applications could be developed.

E.N. Leith, J.U. Upatnieks and C.W. Stroke (all U.S.) of the University of Michigan carried out the first tests in 1963. Since then, holography has developed greatly in the spheres of research, industry and art. The first examples of holography applied to art were achieved by Prof. Youri Denisyouk (U.S.S.R.) who, toward the end of the 1960s, applied holography to the reproduction of works of art. (‘Inventions and Discoveries’)

Sep 19, 2013

Philosophy during China’s Warring States Period

During China’s succeeding Warring States Period (481-221 B.C.), only a handful of states survived. Rulers of states used new technology (such as iron tools) and management techniques to mobilize populations for military service and state-supervised agricultural production. It was a time of population growth and increasing wealth despite near-constant warfare. As rulers looked for new sociopolitical ideas to enhance their power and security, state patronage of learning created a class of literate administrators, advisers, and teachers.

The first and most influential Chinese philosopher was Kongzi (551-479 B.C.), usually known by his Latinate name, Confucius. Confucius, along with later generations of disciples who elaborated upon his ideas (Mencius, Xunzi, and others) advocated a hierarchical society in which the ruler, aided by enlightened ministers, would serve as "father and mother of the people." The Confucians prized harmony, moderation, ritual, and historical precedent but disparaged law, which they saw as the enemy of virtue. Rival thinkers advocated strict codes of law and coercive punishments to control the populace (Shang Yang, Han Feizi); improved managerial techniques to make government more effective (Shen Buhai); frugality, universal love, and self-defense (Mozi); escapism (Yangzi, Zhuangzi); and government by a sage attuned to the rhythms of cosmic force (Laozi). In practice, government during the Warring States Period became increasingly bureaucratic and merit-based, rather than aristocratic and hereditary, as rulers adopted promising ideas and techniques from various schools of thought. (The New York Times ‘Smarter by Sunday – 52 Weekends of Essential Knowledge for the Curious Mind’)

Sep 18, 2013

Quantum theory – how it came about

At the end of the 19th century, no law had been discovered to account for the phenomenon of heat and light radiation by a solid, white-hot body. In 1900 Max Planck (Germany, 1858-1947) guessed that radiation did not occur in a continuous fashion but in small discrete units, separate quantities or quanta. This discovery, which enabled scientists to explain heat radiation, turned physics upside down, especially in the sphere of classical mechanics, which became inoperable in the area of infinitely small quantities. Thanks to this theory, Albert Einstein (Switzerland, b. Germany; 1879-1955) explained in 1905 the photoelectric effect by showing that light, which comprises both waves and particles, moves by quanta, tiny packets of light, which were later called photons.

Niels Bohr (Denmark, 1885-1962) built on this quantum theory a model of an atom, describing in 1911 the movement of electrons inside the atom. This model enabled him to achieve remarkable results in the fields of the spectroscopy of gaseous matter and of X-ray physics. (‘Inventions and Discoveries’)

Sep 17, 2013

One’s susceptibility to heart attacks

The human heart doesn't actually look very much like a valentine, but it is nevertheless a wondrous and beautiful muscle. About the size of a clenched fist, it begins to beat only a few weeks after conception and thereafter pumps forth the rhythm of our lives through every moment of our uterine and earthly existence. Only at the moment of our death does it cease.

This beating has a definite purpose: to pump blood to all parts of the body. The life of our very cells depends on the oxygen and nutrition brought to them by the flow of our blood. If for some reason any muscle did not receive a fresh flow of blood, it would quickly die.

Since the heart is also a muscle, it, too, must continuously receive a fresh flow of blood, and you might think that receiving a blood supply would never be a problem for the heart, since its chambers are always full of blood. But the heart is not able to directly use any of the blood contained within its pumping chambers, any more than a stereo amplifier can plug into itself. Instead, the heart muscle feeds from, the blood supplied to it through two specific vessels, called the coronary arteries.

In a healthy person, the blood flows freely and easily through the coronary arteries, and the well-fed heart keeps pumping away as it should. But if one of the coronary arteries, or one of its branches, should become blocked off and so be unable to supply the heart with blood, then even though the heart's chambers are full of blood, that part of the heart dependent on the blocked-off artery will die.

Sep 16, 2013

The Earth’s origin and composition – earlier attempts to understand

Speculation about the origin and composition of our planet Earth is as old as civilization itself. Most religions contain some form of creation myth, and many hold that the natural forces governing the planet are embodied by gods and spirits. In antiquity, various philosophers propounded theories of the natural world. In the sixth century B.C., Pythagoras correctly noted that the Earth is a sphere, and Aristotle offered plausible, but incorrect, theories for volcanoes, earthquakes, fossils, and other natural phenomena. Pytheas described the tides and noted that they are controlled by the Moon. By the third Century B.C., Eratosthenes calculated the size of the Earth with reasonable precision.

Before the Enlightenment of the 18th century most European scientists were heavily influenced by religious belief, including the biblical story of creation. Scholars attempted to fix the age of Earth through a careful and literal reading of the Bible, concluding that creation took place about 6,000 years ago. But in the 17th century, a few scientists developed ideas that we still believe to be correct today. In 1669, the Danish scientist Nicolas Steno correctly explained fossils as the remains of long-dead organisms and introduced the idea that layers of rock, later called strata by geologists, were deposited at different times, with older layers lying below more recent ones. In Scotland in 1785, an amateur geologist, James Hutton, suggested that Earth's strata must have formed gradually. A half century later, another Scot, Sir Charles Lyell, argued strongly that one could explain geologic history perfectly well by pointing to the geological processes – the action of wind and water, earthquakes, and volcanoes - presently at work and observable on Earth. Lyell rejected the short time derived from the Bible and proposed a much greater period for the development and evolution of Earth. Lyell's notion of a vastly great "geologic time" made possible the evolutionary theory of Lyell's good friend Charles Darwin. It provided the time scale necessary for natural selection to take place. (The New York Times ‘Smarter by Sunday – 52 Weekends of Essential Knowledge for the Curious Mind’)

Sep 15, 2013

How long is the Grand Canyon?

The Grand Canyon, cut out by the Colorado River over a period of 15 million years in the northwest comer of Arizona, is the largest land gorge in the world. It is 4 to 13 miles (6.4 to 21 kilometers) wide at its brim, 4,000 to 5,500 feet (1,219 to 1,676 meters) deep, and 217 miles (349 kilometers) long, extending from the mouth of the Little Colorado River to Grand Wash Cliffs (and 277 miles, 600 feet or 445.88 kilometers if Marble Canyon is included).

However, it is not the deepest canyon in the United States; that distinction belongs to Kings Canyon, which runs through the Sierra and Sequoia National Forests near East Fresno, California, with its deepest point being 8,200 feet (2,500 meters). Hell's Canyon of the Snake River between Idaho and Oregon is the deepest United States canyon in low-relief territory. Also called the Grand Canyon of the Snake, it plunges 7,900 feet (2,408 meters) down from Devil Mountain to the Snake River. (The Handy Science Answer Book, compiled by the Science and Technology department of the Carnegie Library of Pittsburgh)

Sep 14, 2013

Apostle Peter

The sources of knowledge about Peter are the letters of Paul, written between 50 and 60 AD; the four canonical Gospels and Acts of the Apostles, written from about ad65 to the end of the 1st century; two canonical letters bearing Peter's name as author and probably written in the 2nd century by someone other than Peter; and a reference by a Roman presbyter named Gaius (flourished early 3rd century) to a “trophy” on Vatican hill memorializing the place of Peter's martyrdom or burial. In these sources several well-established traditions about Peter are found. He was called by Jesus to be a disciple, and he became prominent among the Twelve, often serving as their spokesman. At Caesarea Philippi he confessed Jesus to be the Messiah and was subsequently rebuked (see Mark 8:33) or praised (see Matthew 16:17) by Jesus for that confession. After Jesus' arrest, Peter denied being associated with him and suffered enormous self-reproach for having done so, but the first appearance of the risen Jesus was to Peter.

Peter played an important role in the early Christian church at Jerusalem, having received a special call to preach the gospel to his fellow Jews. In time, Peter came also to affirm the Christian mission to the Gentiles, whose chief advocate was the apostle Paul. Peter took part in a meeting in Jerusalem that focused decisively on the place of Gentiles in the church (see Acts 15). Against the faction of Jewish Christians who would have required converts to Christianity to be circumcised and to abide by Jewish dietary restrictions, Peter supported those who declared that the Christian message of salvation to all did not require that Gentiles adhere to specific legal and ritual precepts of Judaism.

Sep 13, 2013

Eat at Least 5 Servings of Fruit and Vegetable a Day

Emptier hospitals. Shorter lines at the pharmacy counter. Far fewer of the major diseases that disable and kill millions. If everyone followed the simple and delicious advice of our health experts by eating at least five servings of fruit and vegetables a day, the results would be nothing short of miraculous.

The fact is, we humans are designed to eat these foods by the fistful every day. Our bodies are meant to be flooded with a daily deluge of amazing chemicals called antioxidants that protect cells from damage. And we need them now more than ever. Modern life triggers the production of more free radicals in our bodies than ever before - thanks to fried foods (and simply to overeating!), to more pollution, to the fact that we're living longer, and perhaps even to a thinning atmosphere.

Free radicals are atoms or groups of atoms with an odd number of electrons. They form naturally when we digest food, convert blood sugar into energy, or are exposed to sunlight or pollution. Free radicals destroy cell walls or even worse, DNA itself. The result? Increased cancer risk, cholesterol that's more likely to burrow into artery walls, and damaged cartilage that can't cushion joints properly. Your body uses the antioxidants in fruits and vegetables to neutralize free radicals before they can do harm. Shortchange yourself, and you're essentially letting rogue elements take over your body.