Thursday, 13 June 2013

5 Amazing Scientific Discoveries

Every day, scientists make discoveries that change the way we live. But sometimes, just sometimes, they achieve results that are so extraordinary or unexpected that they literally don't know what to do with them. Here are five of the most puzzling.







Mind-bending material properties


5 Amazing Scientific Discoveries We Don't Know What to Do WithSEXPAND


In January, a team of physicists from Rutgers and MIT published a paper in Nature describing a new property of matter. While fiddling around with a super-cooled Uranium compound, URu2Si2, they found that it breaks something called double time-reversal symmetry. Normal time-reversal symmetry states that the motion of particles looks the same running back and forth in time: magnets break that, though, because if you reverse time, the magnetic field they produce reverses direction. You have to reverse time twice to get them back to their original state.


This new material, though, breaks double time-reversal symmetry. That means you need to reverse time four times for the behaviour to get back to its original state. It's something the scientists have dubbed hastatic order — and if you're struggling to get your head round it, well, that's the appropriate reaction. The scientists who discovered the phenomenon can't explain a good physical example of what it is, how it works, or what it means. One to keep on the back burner, then.







The universe weighs less than we thought


5 Amazing Scientific Discoveries We Don't Know What to Do WithSEXPAND


When the world's best scientists decided to team up and measure the mass of the universe all the way back in the 1970s, they set themselves a pretty tall challenge. Applying their best understanding of gravity and the dynamics of galaxies, though, they came up with an answer — an answer which sadly predicts our universe should be falling apart. We know that the Universe's galaxies' matter orbits a single central point — we've observed it! — and that must mean their own motion generates enough centripetal force to make that happen.


But calculations suggest that there's not actually enough mass in the galaxies to produce the forces required to keep themselves moving in the way we've observed. So physicists scratched their heads, worried a little, then proudly stated that there must be more stuff out there than we can see. That's the theory behind what everyone now refers to as Dark Matter. The only problem? In the past 40 years, nobody has confirmed whether it really exists or not—so, effectively, the problem thrown up by those initial calculations remains.







The placebo effect


5 Amazing Scientific Discoveries We Don't Know What to Do With


Feed a sick man a dummy pill that he thinks will cure him and, often, his health will improve in a similar way to someone taking real drugs. In other words, a bunch of nothing can improve your health. In theory, it could be a powerful treatment technique.


But experiments have shown that the kind of nothing you deliver matters: when placebos are laced with a drug that blocks the effects of morphine, for instance, the effect vanishes. While that proves that the placebo effect is somehow biochemical—and not just a psychological effect—we know practically nothing else about the power of placebo.


It's real, sure. It can help people get better, agreed. But if we're ever to make anything of the much-studied but little-understood effect, we're going to have to unpick how the mind can affect the body's biochemistry—and, right now, nobody knows.







Temperatures below absolute zero


5 Amazing Scientific Discoveries We Don't Know What to Do WithSEXPAND


It used to be that scientists all agreed that it was impossible to achieve temperatures below absolute zero. It was literally the coldest anything could ever get. Late last year, though, a team of scientists from the Max-Planck-Institute in Germany blew that out of the water: finally, they'd cooled a cloud of gas atoms to below −273.15°C. In fact, the result was as much a quirk of the definition of temperature as anything else, and the way it relies on both energy and entropy (the measure of disorder of particles). New Scientist explains:



In principle [it's] possible to keep heating the particles up, while driving their entropy down. Because this breaks the energy-entropy correlation, it marks the start of the negative temperature scale, where the distribution of energies is reversed – instead of most particles having a low energy and a few having a high, most have a high energy and just a few have a low energy.

It's this curious logic that allowed the Max-Planck-Institute researchers to cool a variety of atoms in a vacuum, for the first time ever, to below absolute zero. So far, though, they haven't managed to work out what to do with the chilled particles.







Cold fusion


5 Amazing Scientific Discoveries We Don't Know What to Do With


Back in 1989, a pair of scientists—Fleischmann and Pons—claimed that they'd achieved a remarkable feat: they'd successfully observed nuclear fusion at room temperatures. Momentarily, the finding was heralded as a revolutionary discovery that could transform energy production around the globe. Sadly, their experiments weren't reproducible—but they did inspire scientists to study cold fusion in more depth.


Turns out, the process is in fact theoretically possible. For two atoms two fuse together, they need to come close enough to each other to overcome their mutual electric repulsion, which is caused by the cloud of electrons that orbit them. Usually that's made possible by super-high temperatures—like at the center of the sun—but quantum physics suggests that, because the position of the electric field causing the repulsion is probabilistic, there is at least the possibility that atoms can fuse without the need for energy injection via high temperatures.


And it's that hope that means a small band of scientists still work in the shadows, trying to get cold fusion to work. Of course, while occasional results come and go, they tend to be rather dubious. Fundamentally that's because, even though quantum theory tells us it should be possible, nobody knows how to use that understanding to actually get a fusion reaction going.







The Higgs Boson


5 Amazing Scientific Discoveries We Don't Know What to Do With


Just kiddin'. We've known what to do with Higgs since forever.




Life-Changing Science Discoveries

Try to imagine life without antibiotics. We wouldn’t live nearly as long as we do without them. Here’s a look at some discoveries that have changed the world. It’s impossible to rank their importance, so they’re listed in the order they were discovered.

The Copernicum System


In 1543, while on his deathbed, Polish astronomer Nicholas Copernicus published his theory that the Sun is a motionless body at the center of the solar system, with the planets revolving around it. Before the Copernicum system was introduced, astronomers believed the Earth was at the center of the universe.

Gravity


Isaac Newton, an English mathematician and physicist, is considered the greatest scientist of all time. Among his many discoveries, the most important is probably his law of universal gravitation. In 1664, Newton figured out that gravity is the force that draws objects toward each other. It explained why things fall down and why the planets orbit around the Sun.

Electricity


If electricity makes life easier for us, you can thank Michael Faraday. He made two big discoveries that changed our lives. In 1821, he discovered that when a wire carrying an electric current is placed next to a single magnetic pole, the wire will rotate. This led to the development of the electric motor. Ten years later, he became the first person to produce an electric current by moving a wire through a magnetic field. Faraday's experiment created the first generator, the forerunner of the huge generators that produce our electricity.

Evolution


When Charles Darwin, the British naturalist, came up with the theory of evolution in 1859, he changed our idea of how life on earth developed. Darwin argued that all organisms evolve, or change, very slowly over time. These changes are adaptations that allow a species to survive in its environment. These adaptations happen by chance. If a species doesn't adapt, it may become extinct. He called this process natural selection, but it is often called the survival of the fittest.

Louis Pasteur


Before French chemist Louis Pasteur began experimenting with bacteria in the 1860s, people did not know what caused disease. He not only discovered that disease came from microorganisms, but he also realized that bacteria could be killed by heat and disinfectant. This idea caused doctors to wash their hands and sterilize their instruments, which has saved millions of lives.

Theory of Relativity


Albert Einstein’s theory of special relativity, which he published in 1905, explains the relationships between speed, time and distance. The complicated theory states that the speed of light always remains the same—186,000 miles/second (300,000 km/second) regardless of how fast someone or something is moving toward or away from it. This theory became the foundation for much of modern science.

The Big Bang Theory


Nobody knows exactly how the universe came into existence, but many scientists believe that it happened about 13.7 billion years ago with a massive explosion, called the Big Bang. In 1927, Georges LemaĆ®tre proposed the Big Bang theory of the universe. The theory says that all the matter in the universe was originally compressed into a tiny dot. In a fraction of a second, the dot expanded, and all the matter instantly filled what is now our universe. The event marked the beginning of time. Scientific observations seem to confirm the theory.

Penicillin


Antibiotics are powerful drugs that kill dangerous bacteria in our bodies that make us sick. In 1928, Alexander Flemingdiscovered the first antibiotic, penicillin, which he grew in his lab using mold and fungi. Without antibiotics, infections like strep throat could be deadly.

DNA


On February 28, 1953, James Watson of the United States and Francis Crick of England made one of the greatest scientific discoveries in history. The two scientists found the double-helix structure of DNA. It’s made up of two strands that twist around each other and have an almost endless variety of chemical patterns that create instructions for the human body to follow. Our genes are made of DNA and determine how things like what color hair and eyes we’ll have. In 1962, they were awarded the Nobel Prize for this work. The discovery has helped doctors understand diseases and may someday prevent some illnesses like heart disease and cancer.

Periodic Table


The Periodic Table is based on the 1869 Periodic Law proposed by Russian chemist Dmitry Mendeleev. He had noticed that, when arranged by atomic weight, the chemical elements lined up to form groups with similar properties. He was able to use this to predict the existence of undiscovered elements and note errors in atomic weights. In 1913, Henry Moseley of England confirmed that the table could be made more accurate by arranging the elements by atomic number, which is the number of protons in an atom of the element.

X-Rays


Wilhelm Roentgen, a German physicist, discovered X-rays in 1895. X-rays go right through some substances, like flesh and wood, but are stopped by others, such as bones and lead. This allows them to be used to see broken bones or explosives inside suitcases, which makes them useful for doctors and security officers. For this discovery, Roentgen was awarded the first-ever Nobel Prize in Physics in 1901.

Quantum Theory


Danish physicist Niels Bohr is considered one of the most important figures in modern physics. He won a 1922 Nobel Prize in Physics for his research on the structure of an atom and for his work in the development of the quantum theory. Although he help develop the atomic bomb, he frequently promoted the use of atomic power for peaceful purposes.

Atomic Bomb


The legacy of the atomic bomb is mixed: it successfully put an end to World War II, but ushered in the nuclear arms race. Some of the greatest scientists of the time gathered in the early 1940s to figure out how to refine uranium and build an atomic bomb. Their work was called the Manhattan Project. In 1945, the U.S. dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki. Tens of thousands of civilians were instantly killed, and Japan surrendered. These remain the only two nuclear bombs ever used in battle. Several of the scientists who worked on the Manhattan Project later urged the government to use nuclear power for peaceful purposes only. Nevertheless, many countries continue to stockpile nuclear weapons. Some people say the massive devastation that could result from nuclear weapons actually prevents countries from using them.

HIV/AIDS


In 1983 and 1984, Luc Montagnier of France and Robert Gallo of the United States discovered the HIV virus and determined that it was the cause of AIDS. Scientists have since developed tests to determine if a person has HIV. People who test positive are urged to take precautions to prevent the spread of the disease. Drugs are available to keep HIV and AIDS under control. The hope is that further research will lead to the development of a cure.

Wednesday, 12 June 2013

Oldest Light in the universe-How it travelled to us(Video)

Here it is.....Know how the oldest light in the universe reached us

THE OLDEST LIGHT IN THE UNIVERSE

Stephen Hawking lays out case for Big Bang without God

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PASADENA, Calif. — Our universe didn't need any divine help to burst into being, famed cosmologist Stephen Hawking told a packed house here at the California Institute of Technology Tuesday night.
Many people had begun queuing up for free tickets to Hawking's 8:00 p.m lecture, titled "The Origin of the Universe," 12 hours earlier. By 6:00 p.m. local time, the line was about a quarter-mile long.

 

A second auditorium and a Jumbotron-equipped lawn, which itself was jammed with an estimated 1,000 viewers, were needed to handle the crowd. At least one person was observed offering $1,000 for a ticket, with no success. [Big Bang to Now in 10 Easy Steps]

Stephen Hawking began the event by reciting an African creation myth, and rapidly moved on to big questions such as, Why are we here?

He noted that many people still seek a divine solution to counter the theories of curious physicists, and at one point, he quipped, “What was God doing before the divine creation? Was he preparing hell for people who asked such questions?”

After outlining the historical theological debate about how the universe was created, Hawking gave a quick review of more scientific cosmological explanations, including Fred Hoyle and Thomas Gold’s steady-state theory. This idea hypothesizes that there is no beginning and no end and that galaxies continue to form from spontaneously created matter.
Rod Pyle / Space.com


Enthusiastic attendees started lining up 12 hours early for Stephen Hawking's 8:00 p.m. lecture at Caltech. The overflow crowd stretched for more than a quarter mile.



Hawking said this theory and several other ideas don't hold up, citing recent observations by space telescopes and other instruments.

After giving a brief historical background on relativistic physics and cosmology, Hawking discussed the idea of a repeating Big Bang. He noted that in the 1980s, he and physicist Roger Penrose proved the universe could not “bounce” when it contracted, as had been theorized.

Therefore, time began at the moment of singularity, and this has likely occurred only once, Hawking said. The age of the universe — now believed to be about 13.8 billion years — fits that model, as the number and maturity of observed galaxies seem to fit in the general scheme.

In another observation of modern religion, Hawking noted that in the 1980s, around the time he released a paper discussing the moment the universe was born, Pope John Paul II admonished the scientific establishment against studying the moment of creation, as it was holy.

“I was glad not to be thrown into an inquisition,” Hawking joked.

He closed by outlining "M-theory," which is based partly on ideas put forward years ago by another famed physicist, Caltech’s Richard Feynman. Hawking sees that theory as the only big idea that really explains what he has observed.

M-theory posits that multiple universes are created out of nothing, Hawking explained, with many possible histories and many possible states of existence. In only a few of these states would life be possible, and in fewer still could something like humanity exist. Hawking mentioned that he felt fortunate to be living in this state of existence.

Hawking closed the event with a familiar plea for continued exploration of the cosmos: “We must continue to go into space for the future of humanity,” he said, adding, “I don’t think we will survive another thousand years without escaping our fragile planet.”

Hawking has been battling the debilitating neurological disorder amyotrophic lateral sclerosis, also known as Lou Gehrig's disase, for 50 years.

The physicist has been spending a month or so at Caltech, as he does each year, sequestered with colleagues, such as fellow theoretical physicist Kip Thorne, to discuss many great mysteries of the cosmos.

Stephen Hawking talks about unified theory and his biggest 'blunder'

Humans are on the cusp of discovering how the universe works on its biggest and smallest scales, Stephen Hawking said during a lecture Tuesday in Los Angeles.

The renowned theoretical physicist made his name studying black holes, massive structures that anchor galaxies and whose gravity is so strong that not even light can escape.

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But on Tuesday, he delved into the world of microscopic cell biology to see first-hand how researchers at the Cedars-Sinai Regenerative Medicine Institute are using stem cells to develop treatments for amyotrophic lateral sclerosis, or ALS, the disease Hawking was diagnosed with in 1963.

[For the Record, 9:03 a.m. PDT April 12: An earlier version of this post stated that ALS had kept Stephen Hawking in a wheelchair since 1963. He was diagnosed with the disease in that year.]

In an hourlong talk at Cedars-Sinai for hospital employees, ALS patients and their families, Hawking discussed his childhood, cosmology and what he sees in the universe’s future.

Just minutes after taking a tour of the medical center’s stem cell labs directed toward studying ALS treatments, Hawking drew parallels between the center’s work in discovering the mechanisms of disease and his quest to understand the fundamental rules of the universe.

“If you understand how the universe operates, you control it in a way,” said the author of “A Brief History of Time,” which has sold millions of copies.

The British scholar said his mind’s hunger for answers was never satisfied with what was known growing up. He said he had questions -- most of them theoretical -- that demanded answers. He found his calling at the University of Cambridge’s cosmology department and held the Lucasian Chair in Mathematics at the university for 30 years. Isaac Newton once held the same chair.

At Cambridge, Hawking pioneered groundbreaking research into how particles behaved around black holes, and deduced that the black holes spit out radiation as they swallow up matter. Hawking said his previous, long-held belief that everything swallowed by a black hole was lost forever was the “biggest blunder” of his scientific career.

For him, the answers to the largest and tiniest questions lie in M-theory.

“To understand the universe at the deepest level, we have to understand why is there something rather than nothing,” Hawking said, speaking through a computer program that converts his eye and cheek movements into spoken speech. “Why do we exist? Why this particular set of laws, and not some other? I believe the answers to all of these things is M-theory.”

The theory, he said, combines multiple ideas about math and physics. It suggests that there are multiple dimensions or universes, and offers solutions for the behavior of super-massive black holes and the properties of the fabric of space-time. M-theory is a work in progress, but Hawking said he believes that it’s the most promising lead to a unified theory.

The payoff to solving M-theory, Hawking said, is understanding where we fit in -- and, perhaps, how we can thrive.

“We must continue to go into space for humanity,” Hawking said. “We won’t survive another 1,000 years without escaping our fragile planet.”

 

Kenneth Leeds, associate director of the ethics center at Cedars-Sinai and one of the hospital employees who attended the speech, said he admired the physicist’s accomplishments given his challenges of dealing with ALS.

Leeds has worked with people suffering any number of conditions, so he had a special appreciation of Hawking’s admission that he was afraid to ask his doctor about his diagnosis before he was told he had ALS.

“Here’s a man who’s M.O. is to ask questions, and he didn’t want to ask,” Leeds said. “This is a very human thing.”

Hawking concluded his speech by urging the audience to keep asking questions.

“Your universe is a great triumph,” he said. “I want to share my enthusiasm and excitement about this great quest. So remember to look up at the stars and not at your feet. ... Be curious. And however difficult life may seem, there is always something you can do and succeed at.”

HYDROGEN POWER

Scientists have come up with a more efficient way to split ocean water and turn it into sustainable, clean hydrogen fuel. They created a flexible plastic film that acts as the catalyst to begin splitting ocean water, without requiring the high energy input that current methods need. Using this new technology, as little as five litres of sea water per day would produce enough hydrogen to power an average-sized home and an electric car.

Read more: http://bit.ly/15VshJH

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Comet ISON

A comet  ISON will be seen from all around the globe in late 2013(expected) for several months. don't miss it.it's a lifetime chance.

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Tuesday, 11 June 2013

SCIENCE QUIZ FOR ALL AGES

quiz

want to know how much intelligent you are???

want to know if at all science is your subject???

then here it is...take this science quiz to know your answers....

Go to this link..

http://www.gotoquiz.com/general_science_quiz

10 most mind-bending physics facts

For some of us, physics was something we dreaded at school, abandoning our studies in it at the earliest opportunity, all before reaching adulthood and realising that this particular branch of science is arguably the coolest. Fortunately, there are graduates, postgrads and doctors who had more foresight than people like this humble writer and made the study of physics their life’s work. Here are some of the unbelievably cool things about physics that we have learned because of people like them.


1. Relativity Makes Space Travellers Younger (Kinda)

Both velocity and gravity have an effect on the speed of time; the higher they are, the slower time passes. Astronauts aboard the International Space Station (ISS) (who are in reduced gravity compared to people on Earth but travelling at increased speed around it) experience time more slowly, at a rate of roughly 1 second ‘lost’ every 747 days.

2. Without E=MC2 GPS Would Malfunction

e mc 2

The satellite navigation in your car or on your phone relies on a series of geostationary satellites to pinpoint your location, exchanging data using radio waves. Because of the theory of relativity, the speed at which the satellites’ onboard clocks tick is around 38,000 nanoseconds faster than clocks on the ground. Every time data is sent to the receiving device, a calculation must be applied to correct the timings to within the required 20-30 nanosecond accuracy.

3.’The Speed Of Light’ Isn’t Constant

speed of light

Most people will have heard about the speed of light (c. 671 million miles per hour), which according to all accepted laws of Physics is the fastest that anything can travel. In actual fact, this figure refers only to the speed of light in a vacuum. Really, light is slowed whenever it passes through something, being measured travelling as slowly as just 38 miles per hour at absolute zero (-273.15C) through ultra-cooled rubidium.

4. Humanity Could Fit In A Sugar Cube

sugar cube

Remember when you learned all about the basic structure of the atom – protons, neutrons, electrons? You might recall there was a lot of empty space, and you’d be right. Most of atoms is just empty space, so much so that if you gathered the entire human race together and removed the empty space of all the atoms that make them up you would be left with something no larger than a sugar cube. Incidentally…

5. That Sugar Cube Would Weigh Five Billion Tons

Why? Because all that empty space doesn’t have any mass, so the sugar cube of humanity would be extremely dense. It’s the same principle behind why 1kg of bricks and 1kg of feathers weighs the same, but a box of bricks is denser and has more mass than an equally-sized box of feathers.

6. We Don’t Know What Most Of The Universe Is

question mark

Despite all the advances made in astrophysics in recent years, not least the discovery of various exoplanets beyond our solar system, we don’t know what makes up the majority of the universe. It is possible to make reasonable estimates of the mass of the universe, except that visible matter (stars, planets, stellar objects) only accounts for 2% of that; what exactly makes up the rest – so-called ‘dark matter’ and ‘dark energy’ – remains a mystery.

7. Go Fast, Gain Weight

einstein funny face

Our old friend relativity explains this one as well – mass and energy are equivalent, meaning that as you add energy to a moving object (i.e. increase speed) then that object’s mass increases. At ‘normal’ speeds, this mass gain is pretty negligible, but as you approach the speed of light mass begins to increase dramatically. In case you’re wondering why sprinters and cars and aeroplanes don’t get heavier because of this, don’t worry – the increase in mass as a result of increased speed is only temporary.

8. You Could Be A Walking H-Bomb

hydrogen bomb

The First Law of Thermodynamics holds that in any situation, the total amount of energy in will equal the exact same amount of energy out. As well as meaning that you can’t create energy out of nothing, this law means that you also can not destroy energy. So what happened to all the energy that came from what you put in your own body? The short answer is that most of it remains stored within your body, an average of 7×1018 joules – this amount of energy, if released all at once, would have the same power as 30 hydrogen bombs.

9. You Might Already Have Read This

the big crunch

According to Big Bang cosmology, the universe is constantly expanding. One school of thought suggests that this expansion must eventually not only slow down, but also go into reverse and cause a ‘Big Crunch’. What would happen then is a mystery, but if there is indeed a cycle of ‘bang, expansion, contraction, collapse, bang’, it may well be that the universe plays out in exactly the same way. You might have been born, lived, read this article, lived some more and died in exactly the same way over and over again and not even know it.

10. Another You Might Have Died Reading This

parralel universes

 

According to the multiverse theory (yes, it’s not just a Family Guy thing), there are an infinite number of universes existing parallel to one another, with each differing slightly and every possible scenario being played out in its own universe. This would mean that in at least one universe, a freak accident meant that you were hit by a meteor and killed before finishing this sentence. In another universe, you wouldn’t have even read this article in the first place, because I would have been hit by a meteor and killed before finishing writing it. For a classic 90s TV take on this theory, go look up Sliders on Youtube

Monday, 10 June 2013

3D organ printing

Researchers have 3D printed a functional ear that can ‘hear’ radio frequencies fay beyond the range of human capability. The 3D-printed bionic ear is made up of a coil antenna and cartilage.

Read more: http://bit.ly/1132U5v

Image and information via News at Princeton

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Plastic bottles

Researchers have developed technology that converts plastic waste into cooking gas without causing pollution. The eco-friendly and cheap method involves breaking down shredded plastic waste at an elevated temperature without oxygen, and could help create a more affordable and sustainable gas source for people around the world.

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Latest discoveries

Australian researchers have launched the first bionic eye prototype. The device will allow blind people to see the outlines of their surroundings through a microchip implanted into their skull and a digital camera attached to the sleek-looking glasses. This image shows the rear view of the device.969452_10151721406527518_409034056_n

 

Career of Stephen Hawking

The world celebrated Prof. Stephen Hawking’s 70th birthday on 8 January 2012. We take a look back over his life and work.




Topic of the Moment – the career of Stephen Hawking
Credit: NASA


A brief history of Hawking
Hawking first shot into the public consciousness with the 1988 release of his popular-science book A Brief History of Time, which would remain on theSunday Times bestseller list for an unprecedented four years.

Early in his career, Hawking and his Cambridge colleague Roger Penrose had developed new mathematical tools for use in Einstein’s general relativity.

Using these, they showed that singularities – such as those thought to be at the centre of black holes – are a common feature of the theory, and that, if the effects of quantum mechanics are ignored, the universe must also have begun at a point of infinite density and energy.

It is perhaps for his work on black holes that Hawking is best known.

First, he mathematically proved a theorem by the American physicist John Wheeler that any black hole can be completely described by just three properties – its mass,angular momentum and electric charge.

He then formulated a set of principles that would apply to black holes and be analogous to the usual laws of thermodynamics. Until then, the concept of black holes had presented a problem in that it appeared they allowed the second law of thermodynamics to be broken.

The second law of thermodynamics says that the amount of entropy in a system will always increase. As entropy is a measure of disorder, it would be possible to decrease the total entropy in the universe simply by throwing mass into a black hole.

Hawking’s discovery that the area of a black hole also never decreases led the Mexican-Israeli physicist Jacob Bekenstein to suggest that in some way the area isthe entropy of the black hole. The problem with this was that if a black hole has an entropy then it must have a temperature, and must therefore radiate heat – so it would no longer be black.

Black holes are thought to do precisely this through what is now known as Hawking radiation, which arises due to quantum fluctuations at the black hole’s event horizon. ‘Empty’ space is actually filled with pairs of virtual particles popping into and out of existence, and whereas they would normally vanish effectively instantaneously, in this case, for each pair, one is trapped by the black hole and the other escapes.

If enough time passes, black holes will radiate away all their energy and completely evaporate. The lifetime of a black hole is proportional to the cube of its mass – for a solar-mass black hole it would be around 1067 years.

Cosmology and space advocacy
Hawking then turned his attention back to the universe as a whole.

Along with Jim Hartle of the University of California, Santa Barbara, he developed acosmological model in which the universe has no boundary in spacetime – overturning his own earlier theory that it must have begun with a singularity.

He later proposed a “top-down” cosmological model in which, rather than the universe beginning with a specific set of initial conditions from which it involved into the state that we see today, the present in some sense “selects” the past in much the same way as the observing of a quantum system causes its wavefunction to collapse from superimposed states to one definite condition – such as a living cat or a dead one.

More recently, Hawking has become involved in “space advocacy”, arguing that colonising space is vital to the long-term survival of humanity.

Long-term survival is something that Hawking is very familiar with – having now reached 70 years of age despite a prognosis in his early 20s that, with motor neurone disease, he would only have a few years left to live. Physics has been much better off for his longevity.




An exhibition, Stephen Hawking: A 70th birthday celebration is running at the Science Museum until 9 April

Sunday, 9 June 2013

Stephen Hawking:Biogarphy

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Stephen William Hawking (born 8 January 1942) is a British theoretical physicist, cosmologist, and author. Among his significant scientific works have been a collaboration with Roger Penrose on gravitational singularities theorems in the framework of general relativity, and the theoretical prediction that black holes emit radiation, often called Hawking radiation. Hawking was the first to set forth a cosmology explained by a union of the general theory of relativity and quantum mechanics. He is a vocal supporter of the many-worlds interpretation of quantum mechanics.
He is an Honorary Fellow of the Royal Society of Arts, a lifetime member of the Pontifical Academy of Sciences, and a recipient of the Presidential Medal of Freedom, the highest civilian award in the United States. Hawking was the Lucasian Professor of Mathematics at the University of Cambridge between 1979 and 2009.
Hawking has achieved success with works of popular science in which he discusses his own theories and cosmology in general; his A Brief History of Time stayed on the British Sunday Times best-sellers list for a record-breaking 237 weeks. Hawking has a motor neuron disease related to amyotrophic lateral sclerosis (ALS), a condition that has progressed over the years. He is almost entirely paralysed and communicates through a speech generating device. He married twice and has three children.

Timeline of his recent discoveries
1966 - Completes doctorate and is awarded fellowship at Gonville and Caius College, Cambridge. He works on singularities in the theory of general relativity and applies ideas to the study of black holes.
1968 - Publishes Large Scale Structure of Space-Time
1970 - Discovers that by using quantum theory and general relativity he is able to show that black holes can emit radiation.
1973 - In the same year he joins the department of applied mathematics and theoretical physics at Cambridge, he discovers that black holes could leak energy and particles into space, and could even explode. It is published in the journal Nature, a year later. The theory is known as Hawking radiation.
1976 - Calculates that once a black hole forms, it radiates energy and starts losing mass. The radiation gives no information about matter inside the black hole and once the hole disappears, all the information goes with it.
1988 - Publishes A Brief History of Time: From the Big Bang to Black Holes. The book is a worldwide best seller
1993 - Publishes Black Holes and Baby Universes, and other Essays, a collection of scientific articles exploring ways in which the universe may be governed.
1998 - Publishes Stephen Hawking's Universe: The Cosmos Explained, a book about the basis of existence.
2001 - Publishes Universe in a Nutshell in the UK, a book explaining to a general audience recent breakthroughs in physics.
2002 - Publishes The Theory of Everything: The Origin and Fate of the Universe, a book presenting the most complex theories of physics past and present
2004 - Announces he has solved the Black Hole paradox. In doing so, he concedes that he lost a bet that he an Caltech theorist Kip Thorne had made with John Preskill, also of Caltech, about black holes.
After nearly 30 years of arguing black holes destroy everything that falls into it, he admits that they may allow information within them to escape.

Friday, 7 June 2013

Mind-blowing science facts you may not know

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Cool Science Facts

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1. There are 62,000 miles of blood vessels in the human body – laid end to end they would circle the earth
2. 5 times2. At over 2000 kilometers long, The Great Barrier Reef is the largest living structure on Earth
3. The risk of being struck by a falling meteorite for a human is one occurrence every 9,300 years
4. A thimbleful of a neutron star would weigh over 100 million tons


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5. A typical hurricane produces the energy equivalent of 8,000 one megaton bombs.
6. Blood sucking hookworms inhabit 700 million people worldwide
7. The highest speed ever achieved on a bicycle is 166.94 mph, by Fred Rompelberg
8. We can produce laser light a million times brighter than sunshine
9. 65% of those with autism are left handed
10. The combined length of the roots of a Finnish pine tree is over 30 miles.


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11. The oceans contain enough salt to cover all the continents to a depth of nearly 500 feet
12. The interstellar gas cloud Sagittarius B contains a billion, billion, billion liters of alcohol
13. Polar Bears can run at 25 miles an hour and jump over 6 feet in the air
14. 60-65 million years ago dolphins and humans shared a common ancestor
15. Polar Bears are nearly undetectable by infrared cameras, due to their transparent fur.


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16. The average person accidentally eats 430 bugs each year of their life
17. A single rye plant can spread up to 400 miles of roots underground
18. The temperature on the surface of Mercury exceeds 430 degrees C during the day, and, at night, plummets to minus 180 degrees centigrade
19. The evaporation from a large oak or beech tree is from ten to twenty-five gallons in twenty-four hours
20. Butterflies taste with their hind feet, and their taste sensation works on touch – this allows them to determine whether a leaf is edible


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