"...look into all things with a searching eye” - Baha'u'llah (Prophet Founder of the Baha'i Faith)
Pages
Sep 27, 2014
Oxygen supply to human brain
The arteriograph shows arteries carrying oxygen-rich blood to the brain. The arrangement of the arteries allows blood to be supplied by another route if one of the pathways is blocked. ('The Human Brain Book' by Rita Carter)
Sep 20, 2014
Sep 13, 2014
Region with the fastest growing population in the world
No region of the world is growing faster than sub-Saharan
Africa. Today's population of 926 million may hit 2.2 billion by 2050.
(National Geographic, July 2014)
Sep 6, 2014
Momentum
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| The boulder, unfortunately has more momentum than the runner |
Momentum is the
mass of an object multiplied by its velocity. The momentum of an object depends
on its mass and velocity. This means that an object's momentum changes as it accelerates.
Momentum can be transferred between objects. When a moving ball collides with a
stationary one, for example, the first ball transfers some of its momentum to
the second ball. The total momentum of the two balls is the same as the first
ball's momentum before the collision. This is called the principle of conservation
of momentum.
(Dictionary of Science, by Neil Ardley)
Aug 30, 2014
Aug 23, 2014
Arteries, veins, and capillaries in human body
Three types of blood vessels form a complex network of tubes
throughout the body. Arteries carry blood away from the heart, and veins carry
it toward the heart. Capillaries are the tiny links between the arteries and
the veins where oxygen and nutrients diffuse to body tissues. The inner layer
of blood vessels is lined with endothelial cells that create a smooth passage
for the transit of blood. This inner layer is surrounded by connective tissue
and smooth muscle that enable the blood vessel to expand or contract. Blood
vessels expand during exercise to meet the increased demand for blood and to
cool the body. Blood vessels contract after an injury to reduce bleeding and
also to conserve body heat.
Arteries have thicker walls than veins to withstand the
pressure of blood being pumped from the heart. Blood in the veins is at a lower
pressure, so veins have one-way valves to prevent blood from flowing backwards
away from the heart. Capillaries, the smallest of blood vessels, are only
visible by microscope—ten capillaries lying side by side are barely as thick as
a human hair. If all the arteries, veins, and capillaries in the human body
were placed end to end, the total length would equal more than 100,000 km (more
than 60,000 miles—they could stretch around the earth nearly two and a half
times.
The arteries, veins, and capillaries are divided into two
systems of circulation: systemic and pulmonary. The systemic circulation
carries oxygenated blood from the heart to all the tissues in the body except
the lungs and returns deoxygenated blood carrying waste products, such as
carbon dioxide, back to the heart. The pulmonary circulation carries this spent
blood from the heart to the lungs. In the lungs, the blood releases its carbon
dioxide and absorbs oxygen. The oxygenated blood then returns to the heart
before transferring to the systemic circulation.
(Encarta Encyclopedia)
Aug 16, 2014
There could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of sun-like stars and red dwarf stars within the Milky Way Galaxy
Earth is the only place in the universe known to harbor
life. However, recent advances in planetary science have changed fundamental
assumptions about the possibility of life in the universe, raising the
estimates of habitable zones around other stars, along with the discovery of
hundreds of extrasolar planets and new insights into the extreme habitats here
on Earth, suggesting that there may be many more habitable places in the
universe than considered possible until very recently. On 4 November 2013,
astronomers reported, based on Kepler space mission data, that there could be
as many as 40 billion Earth-sized planets orbiting in the habitable zones of
sun-like stars and red dwarf stars within the Milky Way Galaxy -- 11 billion of
these estimated planets may be orbiting sun-like stars. The nearest such planet
may be 12 light-years away, according to the scientists.
(Wikipedia Encyclopedia)
Aug 9, 2014
English ranks third among the world's most spoken languages
As of 2010, Mandarin was the mother language of 14.4% of the
world’s population, Spanish 6.15%, and English 5.43%.
Although English ranks only third among the world's most
spoken languages, it is on its way to becoming the first truly global language -
used throughout the world as the language of commerce, diplomacy, and science. English
is the mother tongue for some 450 million people, and a further 1.5 billion
people use it as a second language to some degree. Beginning in the 17th
century, the language spread throughout the British Empire to the Americas,
Africa, India, and Oceana. Today 70 countries designate English as an official
language (although it does not have that status in the United States), and it
is an official language of the United Nations, the European Union, Nafta, NATO,
and the Organization of American States.
(Adapted from ‘The New
York Times ‘Smarter by Sunday – 52 Weekends of Essential Knowledge for the
Curious Mind’ and Wikipedia)
Aug 2, 2014
Kilauea – the world’s most active volcanic crater
Kilauea is located on central Hawaii Island, Hawaii. It is
situated on the southeastern slope of the great volcanic mountain Mauna Loa, at
an elevation of 1,247 m (4,090 ft) above sea level, which is more than 3000 m (almost
10,000 ft) below the summit of the mountain. The crater, which forms a great
cavity in the side of the mountain, has an area of about 10 sq km (about 4 sq
mi); the walls of the crater are from 60 to 210 m (about 200 to 700 ft) high.
Except for occasional lava flows across the floor of the crater, volcanic
activity in recent times has been restricted to an inner crater called
Halemaumau, which measures more than 900 m (about 3000 ft) across and has a
depth of about 400 m (about 1300 ft).
Jul 26, 2014
Cardiovascular System – its functions and components
Circulatory system, or cardiovascular system, in humans,
includes the combined functions of the heart, blood, and blood vessels. It transports
oxygen and nutrients to organs and tissues throughout the body and carry away
waste products. Among its vital functions, the circulatory system increases the
flow of blood to meet increased energy demands during exercise and regulates
body temperature. In addition, when foreign substances or organisms invade the
body, the circulatory system swiftly conveys disease-fighting elements of the
immune system, such as white blood cells and antibodies, to regions under
attack. Also, in the case of injury or bleeding, the circulatory system sends
clotting cells and proteins to the affected site, which quickly stop bleeding
and promote healing.
The heart, blood, and blood vessels are the three structural
elements that make up the circulatory system. The heart is the engine of the
circulatory system. It is divided into four chambers: the right atrium, the
right ventricle, the left atrium, and the left ventricle. The walls of these
chambers are made of a special muscle called myocardium, which contracts
continuously and rhythmically to pump blood. The pumping action of the heart
occurs in two stages for each heart beat: diastole, when the heart is at rest;
and systole, when the heart contracts to pump deoxygenated blood toward the
lungs and oxygenated blood to the body. During each heartbeat, typically about
60 to 90 ml (about 2 to 3 oz) of blood are pumped out of the heart. If the
heart stops pumping, death usually occurs within four to five minutes.
Blood consists of
three types of cells: oxygen-bearing red blood cells, disease-fighting white
blood cells, and blood-clotting platelets, all of which are carried through
blood vessels in a liquid called plasma. Plasma is yellowish and consists of
water, salts, proteins, vitamins, minerals, hormones, dissolved gases, and fats.
(Encarta Encyclopedia)
Jul 19, 2014
The combined length of arteries, veins and capillaries in a human body
If all the arteries, veins, and capillaries in the human
body were placed end to end, the total length would equal more than 100,000 km
(more than 60,000 miles — they could stretch around the earth nearly two and a half
times.
(Encarta Encyclopedia)
Jul 12, 2014
Mental Energy - Feel the Flow of Enthusiasm
Call it drive, vigor, enthusiasm, or get-up-and-go. Call it
zest, gusto, razzmatazz, or just plain oomph. It's what gives you ambition,
puts a sparkle in your eye, and fills your day with spirit and glow. It's what
makes you jump out of bed in the morning, fill your lungs with air, and charge
out the front door ready to take on the entire world.
We're talking about the greatest form of energy on earth. It
doesn't come from oil, coal, or natural gas. It comes from your mind.
When the energy is flowing, really flowing, nothing, but nothing,
can stop you. You feel powerful, brilliant, and tremendously alive. You feel
like King Kong with a Ph.D. But, when the energy stops flowing-ugh. You feel
like Dr. Kong after
he fell from the Empire State Building.
If you're like most people, your energy flow can get a little
erratic from time to time, and you'd like to do something about it. You'd like
to boost the wattage and assure yourself of a steady, never-ending supply of
power. Well? Don't just lie there like a
big ape sprawled out on a Manhattan sidewalk! Read the sections below under the
following headings:
A. The Brain in the Energetic Lane
B. Energy Is a State of Mind
C. A Deeper Sense of Self
D. The Will to Succeed
E. Of Body and Mind
Jul 5, 2014
The Eightfold Buddhist Path -- freeing oneself from suffering rooted in ignorance
Buddha’s first teaching to his disciples is reported to have been the
“First Turning of the Wheel of Dharma.”
The Sanskrit word dharma has many shades of meaning. In its original Vedic
context, it meant "duty" in the sense of social obligation, such as the obligation
one feels as
a member of a particular caste. In a Buddhist context, however, the
meaning of dharma
is closer to "truth" or "reality" (or even law,"
as in
law of nature).
The Buddha's first teaching asserted four "truths about
the nature of reality. The first
was that ordinary life is characterized by suffering -- physical suffering,
emotional suffering, and a sort of angst inherent in day-to-day existence. The
second truth was that the cause of this suffering is the desire that follows from all beings'
ignorance of the true nature of reality. The third truth was that it is
possible to attain a state of being in
which suffering is extinguished. The fourth truth concerned the
Eightfold Path leading to that state.
Jun 28, 2014
Alternative technologies concerning energy
What makes a technology conventional is its widespread use,
and what makes it widespread is its low cost and convenience. Therefore, almost
by definition, alternative technologies cost more than conventional ones, at
least in terms of the price paid by the consumer. For example, among
alternative technologies, wind power has come the closest to competing with
conventional fossil fuels, yet it still costs about 50 percent more than coal-generated
electricity. If, however, one takes into account the hidden costs of
conventional energy and the noneconomic benefits of alternative technologies,
then the equation changes.
Growing awareness
of the environmental costs of conventional energy has led to increased demand
for cleaner energy. Global warming, in particular, has altered the way many
people think about the energy they consume - which, in turn, has begun to reshape
the economic relationship between energy producers and consumers. As more and
more consumers sign up for green energy programs and buy hybrid cars (both of
which carry additional costs),
energy companies are reconsidering whether the conventional wisdom of cheap, convenient, and plentiful above
all still applies. Skeptics
argue that the demand for cheap, large-scale energy resources will continue to trump
the relatively new consumer preference for clean, renewable alternatives. On
the other hand, if the era of cheap petroleum-based energy is indeed ending -- as
shrinking petroleum reserves
and rising gasoline prices indicate -- then one may not even have to factor in the hidden costs and benefits for
today's alternative technologies to become tomorrow's conventional resources.
Jun 21, 2014
Slide Rule
A mechanical device formerly used by engineers and
scientists for rapid and approximate multiplication, division, extraction of
roots, raising to powers, and other simple computations. The slide rule has
been almost totally superseded by the small hand-held electronic calculator.
The principle of the slide rule is the translation of all computations to
equivalent additions or subtractions that can be carried out on a set of scales
sliding over each other. Thus, two uniformly graduated marked scales can be
used for addition or subtraction, multiplication, division, powers, and
logarithms. Other scales, such as for sine, cosine, and tangent, and logarithm
and for calculations involving p (pi) are also found on the usual rectilinear
slide rule. A glass runner or cursor with a finely engraved vertical line is
provided for easier alignment of the scales.
The computational accuracy possible depends on the size of
the slide rule and on the care with which the scales are printed. The commonly
used 10-in. slide rule permits multiplications and divisions to be made with an
accuracy of about 1/10th percent, which suffices for many engineering
calculations. Both the rectilinear and the less commonly used circular slide
rule were invented by the English mathematician William Oughtred shortly after
the discovery of logarithms. Various special slide rules have been devised for
the solution of widely applicable engineering formulas, or for business
calculations, such as the determination of interest, compound interest
accumulation, and depreciation.
(Adapted from Encarta Encyclopedia)
Jun 14, 2014
Renewable Energy – wind and solar
The first
wind turbines actually predate the electric power grid, with two
near-simultaneous developments in the late 19th century. The Scottish engineer
James Blyth constructed a 33- foot electricity-generating wind turbine in 1887,
and the following year the American engineer Charles Brush built the first
automatic wind turbine, wiring the first electrically powered building in Ohio.
Likewise, throughout the 1800s, scientists were experimenting in the various
technologies that make photovoltaic
solar panels possible; the first solar powered steam engine was built in 1861.
Since then, the use of wind and solar power has grown steadily, with a surge in
recent years. Wind power, while, still providing a small total percentage of
U.S. power, is growing much more rapidly than solar power. From 1990 to 2008,
U.S. production of wind power grew from 300 trillion Btu annually to 510 trillion;
solar has increased modestly from 60 trillion BN to 90 trillion. Shipments of
solar photovoltaic cells and modules continues to expand, however. From 2000 to
2008, U.S. manufacturers increased shipments of photovoltaic components from 20,000
modules in 2000 to 524,000 modules in 2008. Production of hydroelectric power,
the nation's largest renewable energy source, has remained more or less steady
since 1990, declining somewhat from 3.05 quadrillion Btu to 2.45 quadrillion
Btu in 2008.
Jun 7, 2014
Environmentalism in the United States
The first federal environmental act was the establishment of
Yellowstone National Park in March 1872 in the territories of Montana and
Wyoming. Instead of promoting the land for development, Congress and President
Ulysses S. Grant declared that it should be preserved "as a public park or
pleasuring ground for the benefit and enjoyment of the people." As the first
such preserve in the world, Yellowstone inaugurated an international national
park movement that currently includes some 1,200 parks or preserves in 100 countries,
including 391
in the United States.
The Scottish naturalist John Muir became an early advocate
for preservation after his travels and scientific work convinced him that some natural areas need
protection from human exploitation. Muir founded the Sierra Club in 1892 to
that end and urged President Theodore Roosevelt to join the cause. Roosevelt, himself
known as
an ardent outdoorsman, eventually dedicated more than 150 million acres to national parks and
forests, and founded the US. Forest Service, which manages forests for water
and timber resources while protecting them for wildlife and recreation. The first
chief of the Forest Service, Gifford Pinchot, promoted a "wise use" strategy
of wilderness management that proposed,
in contrast to Muir, that nature could be safely commercialized.
May 31, 2014
The adverse effect of environmental changes on biodiversity
While pollution and global warming have obvious effects on
human health, ecologists also define environmental health according to
biodiversity. Biodiversity measures the variety of living things and their
interactions on three levels: genetics, species, and ecosystem diversity. The
number of known species - characterized by scientific analysis and description -
is more than 1.7 million, including nearly 1 million species of insects, about
14,000 species of amphibians and reptiles, and 5,400 mammalian species. However,
there are many other species living on Earth, including trillions of
microscopic organisms like bacteria. These species interact to form sustainable
check-and balance networks like the food chain.
Human population growth, deforestation, pollution, and
global warming have caused a
rapid loss of biodiversity. Today's extinction rate is estimated to be 1,000 to 10,000 times
higher than the natural rate, and some scientists believe we are in the midst
of a mass extinction. For example, the International Union for Conservation of
Nature reported in 2008 that 30 percent of amphibian species are critically endangered or
vulnerable. This number increased 2,588 percent between 1996 (18 species) and 2010 (484 species).
(Adapted from ‘The New York Times ‘Smarter by Sunday – 52 Weekends of Essential
Knowledge for the Curious Mind’)
May 24, 2014
The world's first designated wilderness
In 1924, due to Aldo Leopold's (an American environmentalist) efforts
as a Forest Service employee, the Gila National Forest in New Mexico became the
world's first designated wilderness. This designation allows travel only by
foot or horseback and bans any commercial activity except grazing in order to
protect the usefulness of the wilderness for cleaning air and reducing climate change,
as well as providing clean water, wildlife habitat, and natural recreational
experiences. (Adapted from ‘The New York Times ‘Smarter by Sunday – 52 Weekends
of Essential Knowledge for the Curious Mind’)
May 17, 2014
Number of known species
The number of known species - characterized by scientific
analysis and description - is more than 1.7 million, including nearly 1 million
species of insects, about 14,000 species of amphibians and reptiles, and 5,400 mammalian
species. It is estimated that there are also trillions of microscopic organisms
like bacteria. (Adapted from 'The New York Times ‘Smarter by Sunday – 52 Weekends of
Essential Knowledge for the Curious Mind’)
May 10, 2014
Air & Liquid Air
Air is the mixture
of gases that surrounds the Earth. Air contains mainly the gases
nitrogen and oxygen, with small amounts of argon and other noble gases and carbon
dioxide. The proportions of these gases in air are the same anywhere around the
world. Air also contains water vapor, dust, and polluting gases, which vary in amount
from place to place. When air is cooled to -328°F (-200°C), most of the gases condense,
forming a blue liquid called liquid air. (Dictionary of Science, by Neil
Ardley)May 3, 2014
America’s Independence Day
Independence Day, commonly known as the Fourth of July, is a
federal holiday in the United States commemorating the adoption of the
Declaration of Independence on July 4, 1776, declaring independence from the
Kingdom of Great Britain (now officially known as the United Kingdom).
Independence Day is commonly associated with fireworks, parades, barbecues,
carnivals, fairs, picnics, concerts, baseball games, family reunions, and
political speeches and ceremonies, in addition to various other public and
private events celebrating the history, government, and traditions of the
United States. Independence Day is the National Day of the United States.
During the American Revolution, the legal separation of the
Thirteen Colonies from Great Britain occurred on July 2, 1776, when the Second
Continental Congress voted to approve a resolution of independence that had
been proposed in June by Richard Henry Leeof Virginia declaring the United
States independent from Great Britain. After voting for independence, Congress
turned its attention to the Declaration of Independence, a statement explaining
this decision, which had been prepared by a Committee of Five, with Thomas
Jefferson as its principal author. Congress debated and revised the wording of
the Declaration, finally approving it on July 4. A day earlier, John Adams had
written to his wife Abigail:
The second day of July, 1776, will be the most memorable
epoch in the history of America. I am apt to believe that it will be celebrated
by succeeding generations as the great anniversary festival. It ought to be
commemorated as the day of deliverance, by solemn acts of devotion to God
Almighty. It ought to be solemnized with pomp and parade, with shows, games,
sports, guns, bells, bonfires, and illuminations, from one end of this
continent to the other, from this time forward forever more.
Apr 26, 2014
Ben-Gurion -- Israel's "founding father" and first Prime Minister
Born David Gruen in Poland, Ben-Gurion became committed to
Zionism, the movement to settle and unite Jews in Palestine, under the
influence of his father and grandfather. He studied in Warsaw, where he joined
Po’alei Zion (Workers of Zion), a socialist workers party. Ben-Gurion saw
Zionism as a practical idea to be carried out by Jewish immigration to
Palestine and building the land through collective labor. In 1906 he moved to
Jaffa, Palestine (now part of Tel Aviv-Yafo, Israel), and worked as a farmer.
There he was elected to the central committee of Po’alei Zion and began
organizing workers into unions. In 1910 he moved to Jerusalem and joined the
editorial staff of a new Hebrew-language newspaper, Ahdut (Unity), publishing
articles under the name Ben-Gurion (Hebrew for "son of the young
lion"). He enrolled at the University of Constantinople in present-day
Turkey in 1912 and earned a law degree in 1914. He then returned to Palestine
and resumed his work as a union organizer, but in 1915 he traveled to the
United States after he and thousands of other Zionists were exiled by the
Ottoman Empire authorities who controlled Palestine.Apr 19, 2014
The Great Wall of China
Great Wall (China), popular name for a semi-legendary wall
built to protect China’s northern border in the 3rd century BC, and for
impressive stone and earthen fortifications built along a different northern
border in the 15th and 16th centuries AD, long after the ancient structure had
disappeared. Ruins of the later wall are found today along former border areas
from Bo Hai (a gulf of the Yellow Sea) in the east to Gansu Province in the
west. The Great Wall is visited often near Beijing, at a site called
Ju-yong-guan, and at its eastern and western extremes.
Perhaps China's best known monument—even national symbol—the
Great Wall is not what most people imagine it to be. The existing wall is not
several thousand years old, nor is it, as is widely asserted, visible from
outer space (astronauts confirm this). Indeed, the Great Wall is not even a
single, continuous structure. Rather, it consists of a network of walls and
towers that leaves the frontier open in places.
Apr 12, 2014
Colonial America: 1492-1763
European nations came to the Americas to increase their
wealth and broaden their influence over world affairs. The Spanish were among
the first Europeans to explore the New World and the first to settle in what is
now the United States.
By 1650, however, England had established a dominant
presence on the Atlantic coast. The first colony was founded at Jamestown,
Virginia, in 1607. Many of the people who settled in the New World came to
escape religious persecution. The Pilgrims, founders of Plymouth,
Massachusetts, arrived in 1620. In both Virginia and Massachusetts, the
colonists flourished with some assistance from Native Americans. New World
grains such as corn kept the colonists from starving while, in Virginia,
tobacco provided a valuable cash crop. By the early 1700s enslaved Africans
made up a growing percentage of the colonial population. By 1770, more than 2
million people lived and worked in Great Britain's 13 North American colonies ( http://www.americaslibrary.gov/)
Apr 5, 2014
September 30, 1882: The World's First Hydroelectric Power Plant Began Operation
When you look at rushing
waterfalls and rivers, you may not immediately think of electricity. But
hydroelectric (water-powered) power plants are responsible for lighting many of
our homes and neighborhoods. On September 30, 1882, the world's first hydroelectric
power plant began operation on the Fox River in Appleton, Wisconsin. The plant,
later named the Appleton Edison Light Company, was initiated by Appleton paper
manufacturer H.J. Rogers, who had been inspired by Thomas Edison's plans for an
electricity-producing station in New York.
Unlike Edison's New York
plant which used steam power to drive its generators, the Appleton plant used
the natural energy of the Fox River. When the plant opened, it produced enough
electricity to light Rogers's home, the plant itself, and a nearby building.
Hydroelectric power plants of today generate a lot more electricity. By the
early 20th century, these plants produced a significant portion of the
country's electric energy. The cheap electricity provided by the plants spurred
industrial growth in many regions of the country. To get even more power out of
the flowing water, the government started building dams.
In 1933, the U.S. government
established the Tennessee Valley Authority (TVA), which introduced
hydroelectric power plants to the South's troubled Tennessee River Valley. The
TVA built dams, managed flood control and soil conservation programs, and more.
It greatly boosted the region's economy. And this development happened in other
places as well. Soon, people across the country were enjoying electricity in
homes, schools, and offices, reading by electric lamp instead of candlelight or
kerosene. New electricity-powered technologies entered American homes,
including electric refrigerators and stoves, radios, televisions, and can
openers. Today, people take electricity for granted, not able to imagine life
without it. (http://www.americaslibrary.gov/)
Mar 29, 2014
Sources of Energy – until 1859 when the first oil well in the United States was drilled in Pennsylvania
When the steam engine was invented at the beginning of the 18th
century, most sources of fuel worldwide were the same as they had been for
centuries: wood for cooking, oil for lighting, coal for heating and industry.
The advent of commercially successful steam power in 1712 allowed for machinery
and engines that were larger and more capable than any machines had ever been, catalyzing the dramatic
changes of the Industrial Revolution. During the 19th century, continuous improvements
to steam engine design transformed factories and built railroads across Europe and
the Americas. Both inventors and engineers knew, however, that steam power had
significant limitations. Steam must be generated by burning fuel, usually coal:
and steam engines were large and bulky to allow for a furnace. The first steam-powered
locomotive, invented in 1804 by the English engineer Richard Trevethick, was so
heavy it broke the rails it rode on. From the earliest days of the Industrial
Revolution, engineers looked for alternatives to steam that would allow for
lighter, more powerful engines.
Internal combustion provided one such alternative. For
centuries, inventors had imagined and tinkered with internal combustion
engines; the medieval Arab scholar Al-Jazari
described twin-cylinder reciprocating pistons in 1206, and Leonardo
da Vinci sketched
compressionless engines in 1509. The modem combustion engine was the British inventor
Robert Street's 1794 model, which used exploding gas to drive the pistons.
Mar 22, 2014
Mar 15, 2014
A black hole is born …
The sun is of only average mass, starwise, and after burning
through the last of its hydrogen fuel in about five billion years, its outer
layers will drift away, and the core will eventually compact to become what's
known as a white dwarf, an Earth-size ember of the cosmos.
For a star ten times as big as the sun, death is far more
dramatic. The outer layers are blasted into space in a supernova explosion
that, for a couple of weeks, is one of the brightest objects in the universe. The
core, meanwhile, is squeezed by gravity into a neutron star, a spinning ball
bearing a dozen miles in diameter. A sugar-cube-size fragment of a neutron star
would weigh a billion tons on Earth; a neutron star's gravitational pull is so
severe that if you were to drop a marshmallow on it, the impact would generate
as much energy as an atom bomb.
But this is nothing compared with the death throes of a star
some 20 times the mass of the sun. Detonate a Hiroshima-like bomb every
millisecond for the entire life of the universe, and you would still fall short
of the energy released in the final moments of a giant-star collapse. The
star's core plunges inward. Temperatures reach 100 billion degrees. The
crushing force of gravity is unstoppable. Hunks of iron bigger than Mount
Everest are compacted almost instantly into grains of sand. Atoms are shattered
into electrons, protons, neutrons. Those minute pieces are pulped into quarks and
leptons and gluons. And so on, tinier and tinier, denser and denser, until. ..
Until no one knows. When trying to explain such a momentous
phenomenon, the two major theories governing the workings of the universe – general
relativity and quantum mechanics – both go haywire, like dials on an airplane
wildly rotating during a tailspin.
The star has become a black hole. (Michael Finkel, National Geographic)
Mar 2, 2014
Water bears – micro-animals theoretically capable of surviving a space journey without protection
Tardigrades (also known as water bears or moss piglets) are water-dwelling, segmented micro-animals, with eight legs. They were first described by the German
pastor J.A.E. Goeze in 1773. The name Tardigrada (meaning "slow
stepper") was given three years later by the Italian biologist Lazzaro
Spallanzani.
Usually,
tardigrades are about 0.5 mm (0.020 in) long when they are fully grown. They
are short and plump with four pairs of legs, each with four to eight claws also
known as "disks". The animals are prevalent in mosses and lichens and
feed on plant cells, algae, and small invertebrates. When collected, they may
be viewed under a very-low-power microscope, making them accessible to students
and amateur scientists. Their mouths have sharp pointy objects, called
stylets. They use their stylets to cut into moss leaves or algae, their main
foods. Then they suck the juices from the plant. Tardigrades live worldwide in moist land
habitats, along rocky shorelines, and on the bottoms of streams, lakes, and
oceans.
Feb 23, 2014
The Four Gospels
A gospel (from Old English, gōd spell "good news")
is a writing that describes the life of Jesus. The word is primarily used to
refer to the four canonical gospels: the Gospel of Matthew, Gospel of Mark,
Gospel of Luke and Gospel of John, probably written between AD 65 and 80. They
appear to have been originally untitled; they were quoted anonymously in the
first half of the second century (i.e. 100 - 150) but the names by which they
are currently known appear suddenly around the year 180. The first canonical
gospel written is thought by most scholars to be Mark (c 65-70). (Wikipedia,
the online free encyclopedia)
Feb 16, 2014
Dolphins can stay constantly alert for more than two weeks
Dolphin (aquatic mammal), fast-swimming mammal belonging to
the order Cetacea, which also includes whales and porpoises. Sleek and powerful
swimmers, dolphins are found in seas throughout the world; some inhabit
freshwater rivers and lakes. Characteristic features of most dolphins are long
snouts with rows of sharp teeth, and rounded foreheads with a nostril on top,
known as the blowhole.
There are at least 40 species of dolphins. Dolphins resemble
fish in many ways, but they exhibit a number of true mammalian characteristics:
They are warm-blooded, breathe air, and nurse their young on milk. Dolphins and
porpoises have a similar appearance, but dolphins can be distinguished from
porpoises by their more prominent snouts and conical teeth. Porpoises have
blunt snouts, chisel-shaped teeth, and a stouter body than dolphins.
Sailors have long considered the presence of dolphins
cruising alongside the bows of ships as a good omen and a promise of fair
weather. Dolphins also figure prominently in folklore, often appearing in works
of art, on coins and currency, and on stamps. Ancient Greek coins depicted the
son of Poseidon seated on a dolphin, and the ancient Roman author Pliny the
Elder wrote a story of a dolphin that carried a poor man's son to school each
day. Many classical writers described how dolphins harnessed to chariots helped
maidens in distress. A dolphin was on the coat of arms of the dauphin, the
title given the eldest son and heir of the king of France.
Feb 9, 2014
Some interesting tidbits about various States of the United States
- Alabama: Was the first state to have 9-1-1, started 1968.
- Alaska: One out of every 64 people has a pilot's license.
- Arizona: Is the only state in the continental U.S. that does not follow Daylight Savings Time.
- Arkansas: Has the only active diamond mine in the U.S.
- California: Its economy is so large that if it were a country, it would rank seventh in the entire world.
- Colorado: In 1976 it became the only state to turn down the Olympics.
- Connecticut: The Frisbee was invented here at Yale University
- Delaware: Has more scientists and engineers than any other state.
- Florida: At 874.3 square miles, Jacksonville is the largest city in the U.S.
- Georgia: It was here, in 1886, that pharmacist John Pemberton made the first vat of Coca-Cola....interesting!
- Hawaii: Hawaiians live, on average, five years longer than residents of any other state.
- Idaho: TV was invented in Rigby, Idaho, in 1922.
- Illinois: Has a Governor in jail, one pending jail, and is the most corrupt state in the union!
Feb 1, 2014
Early Music -- during ancient Greek and Roman empires (500 B.C. to 300 A.D.)
The first European music is that of the ancient Greeks and Romans,
dating from roughly 500 B.C. to A.D. 3OO. Fewer than a dozen examples of Greek
music from this period, written in an alphabetical notation, survive. Ancient
Greek philosophers believed that music originated from the god Apollo, as well
as from the mythological musician Orpheus and other divinities. They also
believed that music reflected in microcosm the laws of harmony that rule the universe,
and that music influenced human thought and actions.
The Greek philosopher Pythagoras (ca. 580 B.C.-ca. 500 B.C.)
discovered the mathematical relationships between specific frequencies and musical inrervals, using a single-string
instrument (called a monochord) to produce the various intervals. For example, two
notes whose frequencies form a ratio of 2:1 sound one octave apart; a ratio of 3:2 forms an interval of a fifth, and a ratio of 4:3 forms a fourth. These basic intervals combine
to create the modes and scales on which all Western melodies and harmony are based.
Jan 26, 2014
How many hairs does the average person have on his or her head and how much does human hair grow in a year?
The
amount of hair covering varies from one individual to another. An average person
has about 100,000 hairs on their scalp. Most redheads have about 90,000 hairs, blonds
have about 140,000, and brunettes fall in between these two figures. Most people
shed between 50 to 100 hairs daily. Each hair grows about 5 inches (12.7 centimeters)
every year. (The Handy Science Answer Book, compiled by the Science and
Technology department of the Carnegie Library of Pittsburgh)
Jan 20, 2014
Can a person get a suntan through a window?
No. The
ultraviolet radiation that causes suntan does not pass through glass. A tan is the
skin 's natural defense against these harmful sun rays. Pigment cells in the
lower skin level make more pigment and melanin to absorb the ultraviolet rays. As
the pigment spreads into the
top layer of the skin, it becomes darker. (The Handy Science Answer Book,
compiled by the Science and Technology department of the Carnegie Library of
Pittsburgh)
Jan 15, 2014
The original meaning of the word “scapegoat”
As described in Leviticus 16:1-27, part of a Hebrew ritual on
the Day of Atonement involved the
presentation of two male goats at the altar of the tabernacle. After lots were cast,
one goat was sacrificed to the Lord; the other, the ‘scapegoat’,
was set aside for Azazel, an evil spirit of the wilderness. The high priest
transferred the sins of the people onto this goat and sent it away into the desert.
(The Book of Answers, by Barbara Berliner)
Jan 10, 2014
What to do when you get sick -- making the right decisions
When you get sick, you must decide what course of action to take in
order to recover your health. If you do not accept this responsibility, others will decide for you and will not
necessarily make the best choices. The most important decision is whether
visits to health professionals will help or hinder your own healing system. You
will need to understand the nature of your illness and to know whether conventional
medicine can do anything for it without reducing the possibility of spontaneous
healing. You will also want to know whether any alternative treatments exist that
might be of benefit.
A good place to start is with a review of what conventional medicine
can do
effectively and what it cannot. For example, it is very effective at managing trauma, so
that if I were in a serious automobile accident, I would want to go directly to
an urgent care facility in a modem hospital,
not to a shaman, guided imagery therapist, or acupuncturist. (Once out of
danger, I might use those other resources to speed up the natural healing process.)
Conventional medicine is also very good at diagnosing and managing crises of
all sorts: hemorrhages, heart attacks, pulmonary edema, acute congestive heart
failure, acute bacterial infections, diabetic comas, bowel obstructions, acute
appendicitis, and so forth. You must be able to recognize symptoms of
potentially serious conditions, so that you will not waste time before
getting needed treatment. In general,
symptoms that are unusually severe, persistent,
or out of the range of your normal experience warrant immediate investigation.
Jan 3, 2014
Color Blindness
Color blindness is a defect of vision affecting the ability
to distinguish colors, occurring mostly in males. It involves a person’s inability
to distinguish one or more of the three colors red, green, and blue. It is
noteworthy to know that the ability to see color exists in only a few
vertebrates, including, among others, man and the other primates, fish,
amphibians, some reptiles, and some birds; and in bees and butterflies.
The first detailed report on this condition was written by the
British chemist John Dalton, who was himself afflicted with it. Total color
blindness, in which all hues are perceived as variations of gray, is known as
achromatopsia or monochromatism. This condition is congenital, extremely rare,
and affects men and women almost equally. Partial color blindness, called
dichromatism, consists generally of the inability to differentiate between the
reds and the greens or to perceive either reds or greens; infrequently, the
confusion may involve the blues or the yellows. Dichromatism is the most common
form of color blindness, affecting about 7 percent of men and less than 1
percent of women. Dichromatism is identified as a sex-linked hereditary
characteristic. Color blindness also may occur as a temporary condition following
a serious illness.
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
Dec 1, 2013
The Splice of Life
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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.
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