(Krishna speaking to Arjuna) II.67. For the mind, which follows in the wake of the wandering senses, carries away his discrimination, as the wind (carries away) a boat on the waters.
COMMENTARY: The mind which constantly dwells on the sensual objects and moves in company with the senses destroys altogether the discrimination of the man. Just as the wind carries away a boat from its course, so also the mind carries away the aspirant from his spiritual path and turns him toward the objects of the senses.
/////////////////////Did evolution come before life?
New research reveals how one cell splits into two during cell division
A rudimentary form of natural selection likely existed in the primordial soup even before life arose on Earth. If so, the complex "ecosystem" of prebiotic molecules may have made the eventual arrival of life much more probable.
To examine how this might occur, Martin Nowak and Hisashi Ohtsuki, mathematical biologists at Harvard University, used simple equations to model the growth of such chains of building-blocks.
The model shows that because longer chains require more assembly reactions, they should be much less common than short chains. And if some assembly reactions run faster than others, then chains built from these fast-assembling sequences of building blocks grow to be most abundant.
Threshold of life
This bare-bones equivalent of natural selection makes the prebiotic soup an interesting place, they say.
"It generates a rich evolutionary dynamic – or what I would want to call a 'prevolutionary' dynamic – where you have diversity, you have information, you have complicated chemistry," says Nowak.
Such a system, full of novel, interacting molecules, would be the ideal milieu to generate a molecule with attributes that would favour the assembly of copies of itself. Nowak's prebiotic selection could then act to refine this ability by ensuring that better replicators become more common.
At some point, Nowak's model predicts, the best replicator may get fast and accurate enough to dominate the population, sucking up all the resources and driving all the other prebiotic sequences extinct. This is the threshold of life.
"Ultimately, life destroys pre-life," says Nowak. "It eats away the scaffold that has built it."
'Murky area'
In showing that selection actually precedes the origin of life, and helps to shape it, Nowak helps bridge the gap between nonliving and living systems. In a sense, he says, the prebiotic soup is constantly testing possible replicators, making it much more probable that one might eventually reach the threshold of life.
Nowak's model helps clarify a murky area of research on prebiotic mixtures, but it offers little direct guidance to experimentalists, says Irene Chen, an origin-of-life researcher also at Harvard.
"The tricky part is figuring out exactly what the relevant chemicals to use are," she says. "Martin's model is basically agnostic about that question."
//////////////////////////////////////////Pack in More of the Three F’s Fun, Fulfilment, and Freedom – what I call the Three F's - embody a whole lot of what people are looking for in life. Here are some quick definitions,
Fun, n. - A source of enjoyment or pleasure; playful activity.
Ful-fill'ment, n. - To bring into actuality; to complete; a feeling of satisfaction at having achieved your desires.
Free-dom, n. - The capacity to exercise choice, free will; frankness or boldness; the absence of constraint in choice or action.
////////////////////////////////////H KELLER-When one door of happiness closes, another opens; but often we look so
long at the closed door that we do not see the one which has been
opened for us.”
//////////////////////////////////
Five Steps to Avoid Overeating
Food
should bring pleasure and satisfaction, but eating in excess often also
brings unnecessary calories, which can lead to unwanted weight gain.
Use these simple tactics to limit your caloric intake while still
enjoying your meals.
Choose fiber-rich fruits and vegetables for appetizers, eat high-calorie foods sparingly, and avoid dishes high in saturated fat and sodium.
Be aware of what you eat.
To help prevent overindulging focus on the act of eating don’t watch
television, surf the Internet or indulge in other distractions. And eat
slowly; it takes 20 minutes for the stomach to signal the brain that
you are full.
Don't starve yourself all day to
justify eating more at dinner. Eating a satisfying breakfast can ward
off the temptation to overindulge later in the day.
Get up from the table when you're done, in order to avoid nibbling.
Once your meal is over, take a walk to help digest your food and think about what a wonderful meal you just had.
///////////////////////////////////////Life is like this: sometimes sun, sometimes rain. ~Proverb, (Fiji)~
///////////////////////////////////////JLTD=JST LKE THE DINOS=MASS EXTINCN
Over at BLDGBLOG,
Geoffrey makes an astute observation about how the latest consumer
technologies have a way of becoming metaphors for the mind. Before the
brain was a binary code running on three pounds of cellular microchips,
it was an impressive calculator, or a camera, or a blank slate. In
other words, we're constantly superimposing the gadgets of the day onto
the cortex. Geoffrey notes that a recent article
featured on the BBC on fMRI scans of taxicab drivers ("Taxi drivers
have brain sat-nav") is very similar to an earlier study, except that
the most recent article used satellite navigation as a metaphor for the
spatial memories storied in the hippocampus:
It's interesting to note, meanwhile, that this appears to
be an almost complete retread of news released more than eight years
ago. There we learn not only that "the hippocampus is at the front of
the brain," but that it "was examined in Magnetic Resonance Imaging
(MRI) scans on 16 London cabbies."
Cabbies' brains, that article reports, "'grow' on the job."
However, it's also interesting to speculate here that "sat-nav" was not
referred to by that earlier article because certain technologies - such
as dashboard navigation and handheld GPS - simply had not yet reached
an adequate price-point, or the required level of social acceptance,
for "sat-nav" to be useful to that writer as a metaphor. If this were
true, then perhaps you could track the infiltration of GPS and sat-nav
technologies into the fabric of everyday life by the speed with which
they have become recognizable as urban-spatial metaphors.
I
was born by Caesarian section at a time when this method of delivery
was fairly rare (too long ago to even mention). The reason was placenta
praevia. Both my children were C-section births, too, both for good
medical reasons. My daughter has now had two C-section deliveries.
These data might lead some to think that C-section deliveries is
hereditary but not so, unless you consider national residence to be
heriditary (which it is but in a non-biological sense). I say this
because the overall rate of Caesarian section deliveries is not
astoundingly high (more than 25% of all live births in 12
industrialized countries; in the US it's 30%). But looking at the
countries themselves one sees huge differences, with nearly 40% in
Italy and Mexico versus only 14% in The Netherlands. Here's a
comparison, courtesy CDC:
When the huge subatomic-particle smasher under the
Swiss-French border starts running, it's supposed to reveal what
happened the instant after the big bang, the theoretical beginning of
our universe 13.7 billion years ago.
The Large Hadron Collider, which suffered a
temporary setback last week, might find some answers. But it will leave
other questions on many people's minds, such as what happened BEFORE
the big bang, and even whether there was a "before."
A scientific mini-industry has
popped up as deep-thinking physicists and cosmologists bat around
various guesses as to what may have happened in a "pre-big bang."
Some of the top minds in this field gathered at Columbia University earlier this month to debate these questions.
"What banged? Where did it come from?" was the question raised by
Laura Mersini-Houghton, a cosmologist at the University of North
Carolina at Chapel Hill.
"Is ours the only universe? If so, how did it come to exist?" asked
Paul Davies, a cosmologist and authority on science and religion at
Arizona State University in Tempe.
Respected scientists have proposed a flock of theories to describe
what might have happened before the birth of our familiar universe of
space and time.
The concepts have fanciful names such as "the big bounce," "the
multiverse," "the cyclic theory," "parallel worlds," even "soap
bubbles." Some propose the existence of multiple universes. Others hold
that there's one universe that recycles itself endlessly, rather as
Buddhists believe. Judeo-Christian theologians may have difficulty
accepting any of these notions.
Most of the hypotheses are variations on an older idea that the
universe has no beginning and no end, contrary to the big-bang theory,
which says that our universe originated at a specific point and will
end sometime in the distant future.
"Neither time nor the universe has a beginning or an end," two
leading cosmologists, Paul Steinhardt of Princeton University and Neil
Turok of Oxford University, wrote in their 2007 book, "Endless
Universe: Beyond the Big Bang."
"The evolution of the universe is cyclic, with big bangs occurring
once every trillion years or so, each one accompanied by the creation
of new matter and radiation that forms new galaxies, stars, planets and
presumably life," they wrote. "Ours is only the most recent cycle."
Some scientists contend that observational evidence may be found to
back up the speculation. They say that no scientific theory can be
considered valid until it's been tested.
"It is becoming increasingly clear that multiverse models grounded
in modern physics can be empirically testable," Max Tegmark, a
theoretical physicist at the University of Pennsylvania, Philadelphia,
wrote in "Parallel Universes," a chapter in the 2003 book "Science and
Ultimate Reality."
Some researchers hope that the Large Hadron Collider will provide
evidence to support or refute these conjectures. They say the particle
smasher might discover extra dimensions, beyond our familiar three
spatial dimensions plus time. More dimensions are the basis of several
pre-big-bang theories.
Michio Kaku, a professor of theoretical physics at the Graduate
Center of the City University of New York, proposes that gravity,
unlike light and matter, could travel between parallel universes and
cast a "shadow" that scientists might be able to detect.
The shadow might take the form of "gravitational waves," faint
ripples in the fabric of space and time caused by violent explosions
such as the big bang. Detectors in the United States and Europe are
seeking such waves, and in the future satellites will watch for
evidence of them in space.
Turok says his cyclic theory predicts a "distinctive pattern of
gravitational waves that is very different from the one expected in the
big-bang theory ... and may prove or disprove our theory within the
next few years."
Last August, ground and satellite observations revealed what
appeared to be an enormous "hole in the universe," a mostly empty
region of the sky, 900 million light-years wide - about 5 billion
trillion miles - in the constellation Eridanus. Mersini-Houghton, a
believer in multiple universes, interpreted the empty spot as the
"footprint" of the gravitational tug of another, smaller universe
parked at the edge of our own.
"It's like someone took a giant scoop and scooped all the matter
away," she told the Columbia cosmology conference. "All these universes
are interacting with each other."
Mersini-Houghton's interpretation of the "hole" is controversial and so far lacks independent confirmation.
The oldest and most popular of the pre-big-bang theories is the
multiverse. As outlined by Martin Rees, the British astronomer royal,
in his 1997 book, "Before the Beginning: Our Universe and Others," the
theory declares that our universe is only one of many - perhaps an
infinite number - of other worlds, each differing slightly from the
others. These universes are continually forming new offspring,
sprouting off from each other rather like soap bubbles.
The big bounce hypothesis - sometimes known as the big splat -
contends that our universe was preceded by a twin that expanded to a
certain limit, then contracted, collapsed and gave birth to our world.
A leading proponent of this theory is Martin Bojowald, a theoretical
physicist at Pennsylvania State University in University Park, who
published it last year in the journal Nature.
In 2005, Kaku published a book titled "Parallel Worlds" in which he
hypothesized that there may be millions of different, parallel
universes, some that look like our own. They're invisible to us because
they lie outside our universe.
The big-bang theory found favor with the Roman Catholic Church
because it implied that the world has a single beginning at a definite
point in time, as portrayed in Genesis. At a Vatican conference in
1951, Pope Pius XII said the big bang was consistent with church
doctrine.
"Creation took place in time, therefore there is a creator, therefore God exists!" the pope declared.
The Rev. John Haught, an authority on science and religion at
Georgetown University in Washington, said the idea that there might be
many worlds and many beginnings, not just a single big bang, wouldn't
undermine Christian theology.
"Even if the universe, or multiverse, were around forever, this
would not challenge the theological explanation of the world's
existence," Haught said. "The biblical doctrine of creation ... lies at
a different level from scientific understanding. The world, theologians
say, still gets its finite being from an infinite being."
According to Francisca Cho, a professor of Buddhism and East Asian
religions at Georgetown, these pre-big-bang cosmologies are similar to
the Hindu belief in a universe that cycles endlessly through creation
and destruction.
/////////////////////////////////////////////
Dark chocolate: Half a bar per week to keep at bay the risk of heart attack
Maybe gourmands are not jumping for joy. Probably
they would have preferred bigger amounts to sup-port their passion.
Though the news is still good for them: 6.7 grams of chocolate per day
represent the ideal amount for a protective effect against inflammation
and subsequent cardiovascular disease.
A new effect, demonstrated for
the first time in a population study by the Research Laboratories of
the Catholic University in Campobasso, in collaboration with the
National Cancer Institute of Milan.
The findings, published in the last issue of the Journal of Nutrition,
official journal of the American So-ciety of Nutrition, come from one
of the largest epidemiological studies ever conducted in Europe, the
Moli-sani Project, which has enrolled 20,000 inhabitants of the Molise
region so far. By studying the participants recruited, researchers
focused on the complex mechanism of inflammation. It is known how a
chronic inflammatory state represents a risk factor for the development
of cardiovascular disease, from myocardial infarction to stroke, just
to mention the major diseases. Keeping the inflammation process un-der
control has become a major issue for prevention programs and C reactive
protein turned out to be one of the most promising markers, detectable
by a simple blood test.
The Italian team related the levels of this protein in the blood of
examined people with their usual choco-late intake. Out of 11,000,
researchers identified 4,849 subjects in good health
and free of risk factors (normal cholesterol, blood pressure and other
parameters). Among them, 1,317 did not use to eat any chocolate, while
824 used to have chocolate regularly, but just the dark one.
"We started from the hypothesis- says Romina di Giuseppe, 33, lead
author of the study- that high amounts of antioxidants contained in the
cocoa seeds, in particular flavonoids and other kinds of poly-phenols,
might have beneficial effects on the inflammatory state. Our results
have been absolutely en-couraging: people having moderate amounts of
dark chocolate regularly have significantly lower levels of C-reactive
protein in their blood. In other words, their inflammatory state is
considerably reduced." The 17% average reduction observed may appear
quite small, but it is enough to decrease the risk of cardio-vascular
disease for one third in women and one fourth in men. It is undoubtedly
a remarkable outcome".
Chocolate amounts are critical. "We are talking of a moderate
consumption. The best effect is obtained by consuming an average amount
of 6.7 grams of chocolate per day, corresponding to a small square of
chocolate twice or three times a week. Beyond these amounts the
beneficial effect tends to disappear".
From a practical point of view, as the common chocolate bar
is 100 grams, the study states that less than half a bar of dark
chocolate consumed during the week may become a healthy habit. What
about the milk chocolate? "Previous studies- the young investigator
continues- have demonstrated that milk interferes with the absorption
of polyphenols. That is why our study considered just the dark
chocolate".
Researchers wanted to sweep all the doubts away. They took into
account that chocolate lovers might consume other healthy food too, as
wine, fruits and vegetables. Or they might exercise more than others
people do. So the observed positive effect might be ascribed to other
factors but not to cocoa itself. "In order to avoid this- researcher
says- we "adjusted" for all possible "confounding" parameters. But the
beneficial effect of chocolate still remained and we do believe it is
real".
"This study- says Licia Iacoviello, Head of the Laboratory of
Genetic and Environmental Epidemiology at the Catholic University of
Campobasso and responsible for the Moli-sani Project- is the first
scientific outcome published from the Moli-sani Project. We consider
this outcome as the beginning of a large se-ries of data which will
give us an innovative view on how making prevention in everyday life,
both against cardiovascular disease and tumors".
"Maybe- Giovanni de Gaetano, director of the Research Laboratories
of the Catholic University of Cam-pobasso, adds - time has come to
reconsider the Mediterranean diet pyramid and take the dark chocolate
off the basket of sweets considered to be bad for our health".
Source: Catholic University
/////////////////////////////////////////Mysterious New 'Dark Flow' Discovered in Space By Clara Moskowitz Staff Writer posted: 23 September 2008 12:46 pm ET
As if the mysteries of dark matter and dark energy weren't vexing
enough, another baffling cosmic puzzle has been discovered.
Patches of matter in the universe seem to be moving at very
high speeds and in a uniform direction that can't be explained by any of the
known gravitational forces in the observable universe. Astronomers are calling
the phenomenon "dark flow."
The stuff that's pulling this matter must be outside
the observable universe, researchers conclude.
When scientists talk about the observable
universe, they don't just mean as far out as the eye, or even the most
powerful telescope, can see. In fact there's a fundamental limit to how much of
the universe we could ever observe, no matter how advanced our visual
instruments. The universe is thought to have formed about 13.7 billion years
ago. So even if light started travelling toward us immediately after the Big Bang,
the farthest it could ever get is 13.7 billion light-years in distance. There
may be parts of the universe that are farther away (we can't know how big the
whole universe is), but we can't see farther than light could travel over the
entire age of the universe.
Mysterious motions
Scientists discovered the flow by studying some of the
largest structures in the cosmos: giant
clusters of galaxies. These clusters are conglomerations of about a
thousand galaxies, as well as very hot gas which emits X-rays. By observing the
interaction of the X-rays with the cosmic microwave background (CMB), which is
leftover radiation from the Big Bang, scientists can study the movement of
clusters.
The X-rays scatter photons in the CMB, shifting
its
temperature in an effect known as the kinematic Sunyaev-Zel'dovich (SZ)
effect.
This effect had not been observed as a result of galaxy clusters
before, but a
team of researchers led by Alexander Kashlinsky, an astrophysicist at
NASA's Goddard Space Flight Center in Greenbelt, Md., found it when
they studied a huge catalogue of
700 clusters, reaching out up to 6 billion light-years, or half the
universe
away. They compared this catalogue to the map
of the CMB taken by NASA's Wilkinson Microwave Anisotropy Probe (WMAP)
satellite.
They discovered that the clusters were moving nearly 2
million mph (3.2 million kph)toward a region in the sky between the
constellations of Centaurus and Vela. This motion is different from the outward
expansion of the universe (which is accelerated by the force called dark
energy).
"We found a very significant velocity, and furthermore,
this velocity does not decrease with distance, as far as we can measure,"
Kashlinsky told SPACE.com. "The matter in the observable universe
just cannot produce the flow we measure."
Inflationary bubble
The scientists deduced that whatever is driving the
movements of the clusters must lie beyond the known universe.
A theory called inflation posits that the universe we see is
just a small bubble of space-time that got rapidly expanded after the Big Bang.
There could be other parts of the cosmos beyond this bubble that we cannot see.
In these regions, space-time might be very different, and
likely doesn't contain stars and galaxies (which only formed because of the
particular density pattern of mass in our bubble). It could include giant,
massive structures much larger than anything in our own observable universe.
These structures are what researchers suspect are tugging on the galaxy
clusters, causing the dark flow.
"The structures responsible for this motion have been
pushed so far away by inflation, I would guesstimate they may be hundreds of
billions of light years away, that we cannot see even with the deepest
telescopes because the light emitted there could not have reached us in the age
of the universe," Kashlinsky said in a telephone interview. "Most
likely to create such a coherent flow they would have to be some very strange
structures, maybe some warped space time. But this is just pure
speculation."
Surprising find
Though inflation theory forecasts many odd facets of the
distant universe, not many scientists predicted the dark flow.
"It was greatly surprising to us and I suspect to
everyone else," Kashlinsky said. "For some particular models of
inflation you would expect these kinds of structures, and there were some
suggestions in the literature that were not taken seriously I think until
now."
The discovery could help scientists probe what happened to
the universe before
inflation, and what's going on in those inaccessible realms we cannot see.
The researchers detail their findings in the Oct. 20 issue
of the journal Astrophysical Journal Letters.
////////////////////////////////////////BAPE-CDE CRSS LIKE SITUATN
//////////////////////////////////////////TAPCHIDU6 CRSS LIKE SITUTN
Why is something beautiful? David Hume argued that beauty exists not
in things but "in the mind that contemplates them." And everyone has at
some point heard the old saw that beauty is in the eye of the beholder.
But Plato had a fanciful answer made to argue for a universal truth: In
his world of forms, he claimed there existed a perfect Form of Beauty,
which was imperfectly manifested in what we call beautiful. Despite the
allure of Plato's metaphorical claim, students of aesthetics have
struggled to substantiate it. Evolutionary psychologists have argued
that there exist quantifiable, describable, universal aspects to the
human capacity for appreciating beautiful forms, perhaps originating in
our ancestors' experience on African savannas or in the need to find
suitable mates. They have not solved the problem. However, recent work
by several researchers at University College London?—?including the
establishment of the first major grant-driven research program for the
neurobiological investigation of aesthetics, or neuroaesthetics?—?has
made the first steps toward a unified biocultural theory of art. An
object's beauty may not be universal, but the neural basis for
appreciating beauty probably is. The researchers' initial discoveries
and the increasing formalization of the field promise to open the way
for the first time to an understanding of beauty based on something
other than speculation.
Advertisement
The first studies of aesthetics and the
brain began with the sort of self-experimentation that science doesn't
encourage anymore. In the 1920s neurologist Heinrich Klüver documented
the hallucinations he experienced while under the influence of
mescaline, using four categories: grids, zigzags, spirals, and curves.
Noting their similarity to the hallucinations experienced in various
conditions, such as migraine, sensory deprivation, and the hypnagogic
state that occurs in the transition from wakefulness to sleep, he named
them "form constants." These motifs do indeed seem to be
constant?—?they recur throughout history and across cultures, and can
be seen, for example, in prehistoric cave paintings, in the girih
patterns of the tile mosaics decorating medieval mosques, and in the
repeating tessellations of M.C. Escher's impossible figures or the
rectangular forms of Mondrian's Compositions. Underlying those
patterns, at least in part, are the intrinsic properties of the visual
nervous system. Most neurons in the primary visual cortex occur in
repeating structures called ocular dominance columns; these in turn are
organized into hypercolumns, whose long-range interconnections are
arranged geometrically. The spontaneous activity of these neural
networks gives rise to the patterns Klüver studied.
The "uglier" a painting, the greater the motor cortex activity, as if the brain was preparing to escape.
Such investigations of the biology of aesthetics, however, had
heretofore not been anyone's primary research focus; rather, the
investigations have been subordinated to some other work, such as
modelling the visual system. Semir Zeki of University College London is
pioneering modern neuroaesthetics, and, thanks in part to a £1 million
grant from the Wellcome Trust in the UK last autumn, is forging ahead
with a research program that tries to establish the neurobiological
underpinnings for creativity, beauty, and even love.
Zeki's work has been ongoing for several years. In 2004 he led a
neuroimaging study designed to investigate the neural correlates of
beauty. Ten participants were shown 300 paintings and asked to classify
each of them as beautiful, ugly, or neutral. Paintings rated as
beautiful by some of the participants were rated as ugly by others, and
vice versa. The participants were then shown the paintings again while
lying in a scanner. "Beautiful" paintings elicited increased activity
in the orbito-frontal cortex, which is involved in emotion and reward.
Interestingly, the "uglier" a painting, the greater the motor cortex
activity, as if the brain was preparing to escape. More recently, Zeki
has started to collaborate with scholars from the arts and humanities
under the guidance of a multidisciplinary advisory board that includes
author A.S. Byatt and Jonathan Miller, a physician and opera producer.
Richard Morris, head of neuroscience and mental health at the
Wellcome Trust, says Zeki's work "gives insight into what it is to be
human." And according to Wellcome senior scientist John Williams, could
reveal some of the underpinnings of conditions, such as depression,
that are marked by a reduced aesthetic sense.
Elsewhere at UCL, neuroscientist Hugo Spiers is investigating how
the brain encodes direction, location, and the dimensions of
space?—?the implications for architecture could be profound. Spiers
recently collaborated with artist Antoni Malinowski and architect
Bettina Vismann on a project that aimed to explore the relationship
between art, architecture, and the brain. Funded by the Wellcome Trust,
the project resulted in an installation called Neurotopographics,
which tracked the relationship between movement though space and the
activity of the brain. "When someone traverses a space, their brain
produces an oscillating, rhythmic pattern," Spiers explains. "We tried
to realize this abstract understanding into an everyday reality."
As for architecture, altering space can have a large impact on brain
function. Changing the dimensions of an animal's enclosure causes grid
cells to alter their scales accordingly, such that the periodicity of
their firing, which is observed as the animal moves across a space,
increases or decreases. Surprisingly, negotiating a corridor in
opposite directions elicits completely different patterns of place-cell
activity, so the same space is apparently encoded as two different
places. A less surprising but still important finding is that the lack
of easily recognizable landmarks causes disorientation. Spiers and his
colleagues are now investigating how the brain encodes
three-dimensional space. While recording neuronal activity as rats
negotiated a spiral staircase, they found that place cells, but not
grid cells, respond to changes in height. Thus, the brain seems to
encode the vertical and horizontal dimensions in different ways.
Such knowledge of spatial cognition provides an understanding of the
brain's response to the built environment and can inform architects as
they consider the aesthetic elements and function of a space. "From an
architectural point of view," says Vismann, "I find the correspondence
between what occurs in the brain and the physical nature of space and
spatial navigation fascinating." She expects that understanding the
neural bases of spatial perception will inspire projects, inform the
design process, and help formulate ways of organizing space.
Future work may elucidate the long-term effects of one's
surroundings on brain function and the relationship between
aesthetically pleasing spaces and their functionality. What one
considers beautiful is, of course, influenced by culture, learning, and
experience, and not everything we find beautiful will ultimately be
traceable to the structure and function of our brain. The larger
question "What is beauty?" still poses a major challenge, but answering
it no longer seems so impossible.
//////////////////////////////Judy writes: "And for awhile at least, through us (and probably
elsewhere through others), the universe knows something of itself, and
this also is cause for celebration. "
Amen. A beautiful idea. There are two things that have obscured this
idea. One is the belief that there is a conscious God "out there." The
other is that we (as humans) are somehow outside of the realm of
Nature. But once we accept the idea that there is not some disembodied
god out there, and also that we are fully a part of Nature, then the
idea emerges that when we observe, ponder, and appreciate the Universe,
we are the Universe observing, pondering, and appreciating itself.
Through being conscious we "realize" the Universe, we make it real.
(Imagine a universe just like this one, but that never puts forth a
living, aware being. In what sense does it exist? In what sense does it
matter?) In a way, we are each of us a kind of Atlas, holding the
universe on our shoulders (in the awareness of our heads). And if one
takes this seriously, then one may find it a virtue to try to be more
deeply observant, thoughtful, and appreciative of the Universe (which
includes our own being).
Thomas
////////////////////////////Always bear in mind that your own resolution to succeed is more important than any other.
— Abraham Lincoln
//////////////////////////////“Because we all share this small planet earth, we have to learn to live
in harmony and peace with each other and with nature. That is not just
a dream, but a necessity.”
///////////////////////////////////////Ondansetron Therapy May Improve Outcomes in Children With Gastroenteritis
Ondansetron decreased the risk for persistent vomiting, intravenous
fluid use, and hospitalizations in children presenting to the emergency
department for vomiting from gastroenteritis.
Medscape Medical News 2008
///////////////////////////////////////Respiratory Viral Infections Tied to Pediatric Pneumococcal Disease
Respiratory viral infections are associated with an increased risk
of subsequent seasonal invasive pneumococcal disease in children,
researchers report in the August issue of Pediatrics.
Reuters Health Information 2008
///////////////////////////////////////////
Nut Allergies Foremost in Pediatric Anaphylaxis
A review of anaphylaxis episodes in children shows that most
reactions occur at home, most are triggered by peanuts or cashews, and
treatment is often delayed.
Reuters Health Information 2008
A trained German Shepherd reportedly dialed 911 to save it's master - another proof that dog is a man's bestfriend.
This
is the third time that Buddy, the dog's name, called the 911 to save
it's owner's. Joe Stalnaker, life who suffered a head injury during
military training.
Buddy was trained and can press programmed buttons to called 911 whenever it sense it's owner is having a seizure symptoms.
Big Bang or Big Bounce?: New Theory on the Universe's Birth
Our
universe may have started not with a big bang but with a big bounce—an
implosion that triggered an explosion, all driven by exotic
quantum-gravitational effects
By Martin Bojowald
Atoms
are now such a commonplace idea that it is hard to remember how radical
they used to seem. When scientists first hypothesized atoms centuries
ago, they despaired of ever observing anything so small, and many
questioned whether the concept of atoms could even be called
scientific. Gradually, however, evidence for atoms accumulated and
reached a tipping point with Albert Einstein’s 1905 analysis of
Brownian motion, the random jittering of dust grains in a fluid. Even
then, it took another 20 years for physicists to develop a theory
explaining atoms—namely, quantum mechanics—and another 30 for physicist
Erwin Müller to make the first microscope images of them. Today entire
industries are based on the characteristic properties of atomic matter.
Physicists’ understanding of the composition of space and time is
following a similar path, but several steps behind. Just as the
behavior of materials indicates that they consist of atoms, the
behavior of space and time suggests that they, too, have some
fine-scale structure—either a mosaic of spacetime “atoms” or some other
filigree work. Material atoms are the smallest indivisible units of
chemical compounds; similarly, the putative space atoms are the
smallest indivisible units of distance. They are generally thought to
be about 10–35 meter in size, far too tiny to be seen by today’s most powerful instruments, which probe distances as short as 10–18
meter. Consequently, many scientists question whether the concept of
atomic spacetime can even be called scientific. Undeterred, other
researchers are coming up with possible ways to detect such atoms
indirectly.
The most promising involve observations of the cosmos. If we imagine
rewinding the expansion of the universe back in time, the galaxies we
see all seem to converge on a single infinitesimal point: the big bang
singularity. At this point, our current theory of gravity—Einstein’s
general theory of relativity—predicts that the universe had an infinite
density and temperature. This moment is sometimes sold as the beginning
of the universe, the birth of matter, space and time. Such an
interpretation, however, goes too far, because the infinite values
indicate that general relativity itself breaks down. To explain what
really happened at the big bang, physicists must transcend relativity.
We must develop a theory of quantum gravity, which would capture the
fine structure of spacetime to which relativity is blind.
The details of that structure came into play under the dense
conditions of the primordial universe, and traces of it may survive in
the present-day arrangement of matter and radiation. In short, if
spacetime atoms exist, it will not take centuries to find the evidence,
as it did for material atoms. With some luck, we may know within the
coming decade.
Pieces of Space
Physicists have devised several candidate theories of quantum gravity,
each applying quantum principles to general relativity in a distinct
way. My work focuses on the theory of loop quantum gravity (“loop
gravity,” for short), which was developed in the 1990s using a two-step
procedure. First, theorists mathematically reformulated general
relativity to resemble the classical theory of electromagnetism; the
eponymous “loops” of the theory are analogues of electric and magnetic
field lines. Second, following innovative procedures, some that are
akin to the mathematics of knots, they applied quantum principles to
the loops. The resulting quantum gravity theory predicts the existence
of spacetime atoms [see “Atoms of Space and Time,” by Lee Smolin; Scientific American, January 2004].
Other approaches, such as string theory and so-called causal
dynamical triangulations, do not predict spacetime atoms per se but
suggest other ways that sufficiently short distances might be
indivisible [see “The Great Cosmic Roller-Coaster Ride,” by Cliff Burgess and Fernando Quevedo; Scientific American, November 2007, and “The Self-Organizing Quantum Universe,”
by Jan Ambjørn, Jerzy Jurkiewicz and Renate Loll; Scientific American,
July]. The differences among these theories have given rise to
controversy, but to my mind the theories are not contradictory so much
as complementary. String theory, for example, is very useful for a
unified view of particle interactions, including gravity when it is
weak. For the purpose of disentangling what happens at the singularity,
where gravity is strong, the atomic constructions of loop gravity are
more useful.
The theory’s power is its ability to capture the
fluidity of spacetime. Einstein’s great insight was that spacetime is
no mere stage on which the drama of the universe unfolds. It is an
actor in its own right. It not only determines the motion of bodies
within the universe, but it evolves. A complicated interplay between
matter and spacetime ensues. Space can grow and shrink.
Loop gravity extends this insight into the quantum realm. It takes
our familiar understanding of particles of matter and applies it to the
atoms of space and time, providing a unified view of our most basic
concepts. For instance, the quantum theory of electromagnetism
describes a vacuum devoid of particles such as photons, and each
increment of energy added to this vacuum generates a new particle. In
the quantum theory of gravity, a vacuum is the absence of spacetime—an
emptiness so thorough we can scarcely imagine it. Loop gravity
describes how each increment of energy added to this vacuum generates a
new atom of spacetime.
The spacetime atoms form a dense, ever shifting mesh. Over large
distances, their dynamism gives rise to the evolving universe of
classical general relativity. Under ordinary conditions, we never
notice the existence of these spacetime atoms; the mesh spacing is so
tight that it looks like a continuum. But when spacetime is packed with
energy, as it was at the big bang, the fine structure of spacetime
becomes a factor, and the predictions of loop gravity diverge from
those of general relativity.
Attracted to Repulsion
Applying the theory is an extremely complex task, so my colleagues and
I use simplified versions that capture the truly essential features of
the universe, such as its size, and ignore details of lesser interest.
We have also had to adapt many of the standard mathematical tools of
physics and cosmology. For instance, theoretical physicists commonly
describe the world using differential equations, which specify the rate
of change of physical variables, such as density, at each point in the
spacetime continuum. But when spacetime is grainy, we instead use
so-called difference equations, which break up the continuum into
discrete intervals. These equations describe how a universe climbs up
the ladder of sizes that it is allowed to take as it grows. When I set
out to analyze the cosmological implications of loop gravity in 1999,
most researchers expected that these difference equations would simply
reproduce old results in disguise. But unexpected features soon emerged.
Gravity is typically an attractive force. A ball of matter tends to
collapse under its own weight, and if its mass is sufficiently large,
gravity overpowers all other forces and compresses the ball into a
singularity, such as the one at the center of a black hole. But loop
gravity suggests that the atomic structure of spacetime changes the
nature of gravity at very high energy densities, making it repulsive.
Imagine space as a sponge and mass and energy as water. The porous
sponge can store water but only up to a certain amount. Fully soaked,
it can absorb no more and instead repels water. Similarly, an atomic
quantum space is porous and has a finite amount of storage space for
energy. When energy densities become too large, repulsive forces come
into play. The continuous space of general relativity, in contrast, can
store a limitless amount of energy.
Because of the quantum-gravitational change in the balance of
forces, no singularity—no state of infinite density—can ever arise.
According to this model, matter in the early universe had a very high
but finite density, the equivalent of a trillion suns in every
proton-size region. At such extremes, gravity acted as a repulsive
force, causing space to expand; as densities moderated, gravity
switched to being the attractive force we all know. Inertia has kept
the expansion going to the present day.
In fact, the repulsive gravity caused space to expand at an
accelerating rate. Cosmological observations appear to require such an
early period of acceleration, known as cosmic inflation. As the
universe expands, the force driving inflation slowly subsides. Once the
acceleration ends, surplus energy is transferred to ordinary matter,
which begins to fill the universe in a process called reheating. In
current models, inflation is somewhat ad hoc—added in to conform to
observations—but in loop quantum cosmology, it is a natural consequence
of the atomic nature of spacetime. Acceleration automatically occurs
when the universe is small and its porous nature still quite
significant.
Time before Time
Without a singularity to demarcate the beginning of time, the history
of the universe may extend further back than cosmologists once thought
possible. Other physicists have reached a similar conclusion [see “The
Myth of the Beginning of Time,” by Gabriele Veneziano; Scientific
American, May 2004], but only rarely do their models fully resolve the
singularity; most models, including those from string theory, require
assumptions as to what might have happened at this uneasy spot. Loop
gravity, in contrast, is able to trace what took place at the
singularity. Loop-based scenarios, though admittedly simplified, are
founded on general principles and avoid introducing new ad hoc
assumptions.
Using the difference equations, we can try to reconstruct the deep
past. One possible scenario is that the initial high-density state
arose when a preexisting universe collapsed under the attractive force
of gravity. The density grew so high that gravity switched to being
repulsive, and the universe started expanding again. Cosmologists refer
to this process as a bounce.
The first bounce model investigated thoroughly was an idealized case
in which the universe was highly symmetrical and contained just one
type of matter. Particles had no mass and did not interact with one
another. Simplified though this model was, understanding it initially
required a set of numerical simulations that were completed only in
2006 by Abhay Ashtekar, Tomasz Pawlowski and Parampreet Singh, all at
Pennsylvania State University. They considered the propagation of waves
representing the universe both before and after the big bang. The model
clearly showed that a wave would not blindly follow the classical
trajectory into the abyss of a singularity but would stop and turn back
once the repulsion of quantum gravity set in.
An exciting result of these simulations was that the notorious
uncertainty of quantum mechanics seemed to remain fairly muted during
the bounce. A wave remained localized throughout the bounce rather than
spreading out, as quantum waves usually do. Taken at face value, this
result suggested that the universe before the bounce was remarkably
similar to our own: governed by general relativity and perhaps filled
with stars and galaxies. If so, we should be able to extrapolate from
our universe back in time, through the bounce, and deduce what came
before, much as we can reconstruct the paths of two billiard balls
before a collision based on their paths after the collision. We do not
need to know each and every atomic-scale detail of the collision.
Unfortunately, my subsequent analysis dashed this hope. The model as
well as the quantum waves used in the numerical simulations turned out
to be a special case. In general, I found that waves spread out and
that quantum effects were strong enough to be reckoned with. So the
bounce was not a brief push by a repulsive force, like the collision of
billiard balls. Instead it may have represented the emergence of our
universe from an almost unfathomable quantum state—a world in highly
fluctuating turmoil. Even if the preexisting universe was once very
similar to ours, it passed through an extended period during which the
density of matter and energy fluctuated strongly and randomly,
scrambling everything.
The fluctuations before and after the big bang were not strongly
related to each other. The universe before the big bang could have been
fluctuating very differently than it did afterward, and those details
did not survive the bounce. The universe, in short, has a tragic case
of forgetfulness. It may have existed before the big bang, but quantum
effects during the bounce wiped out almost all traces of this
prehistory.
Some Scraps of Memory
This picture of the big bang is subtler than the classical view of the
singularity. Whereas general relativity simply fails at the
singularity, loop quantum gravity is able to handle the extreme
conditions there. The big bang is no longer a physical beginning or a
mathematical singularity, but it does put a practical limitation on our
knowledge. Whatever survives cannot provide a complete view of what
came before.
Frustrating
as this may be, it might be a conceptual blessing. In physical systems
as in daily life, disorder tends to increase. This principle, known as
the second law of thermodynamics, is an argument against an eternal
universe. If order has been decreasing for an infinite span of time,
the universe should by now be so disorganized that structures we see in
galaxies as well as on Earth would be all but impossible. The right
amount of cosmic forgetfulness may come to the rescue by presenting the
young, growing universe with a clean slate irrespective of all the mess
that may have built up before.
According to traditional thermodynamics, there is no such thing as a
truly clean slate; every system always retains a memory of its past in
the configuration of its atoms [see “The Cosmic Origins of Time’s Arrow,”
by Sean M. Carroll; Scientific American, June]. But by allowing the
number of spacetime atoms to change, loop quantum gravity allows the
universe more freedom to tidy up than classical physics would suggest.
All that is not to say that cosmologists have no hope of probing the
quantum-gravitational period. Gravitational waves and neutrinos are
especially promising tools, because they barely interact with matter
and therefore penetrated the primordial plasma with minimal loss. These
messengers might well bring us news from a time near to, or even
before, the big bang.
One way to look for gravitational waves is by studying their imprint
on the cosmic microwave background radiation [see “Echoes from the Big
Bang,” by Robert R. Caldwell and Marc Kamionkowski; Scientific
American, January 2001]. If quantum-gravitational repulsive gravity
drove cosmic inflation, these observations might find some hint of it.
Theorists must also determine whether this novel source of inflation
could reproduce other cosmological measurements, especially of the
early density distribution of matter seen in the cosmic microwave
background.
At the same time, astronomers can look for the spacetime analogues
of random Brownian motion. For instance, quantum fluctuations of
spacetime could affect the propagation of light over long distances.
According to loop gravity, a light wave cannot be continuous; it must
fit on the lattice of space. The smaller the wavelength, the more the
lattice distorts it. In a sense, the spacetime atoms buffet the wave.
As a consequence, light of different wavelengths travels at different
speeds. Although these differences are tiny, they may add up during a
long trip. Distant sources such as gamma-ray bursts offer the best hope
of seeing this effect [see “Window on the Extreme Universe,” by William B. Atwood, Peter F. Michelson and Steven Ritz; Scientific American, December 2007].
In the case of material atoms, more than 25 centuries elapsed
between the first speculative suggestions of atoms by ancient
philosophers and Einstein’s analysis of Brownian motion, which firmly
established atoms as the subject of experimental science. The delay
should not be as long for spacetime atoms.
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