Scientists reveal secret of levitation

Scientists have discovered a ground-breaking way of levitating ultra small objects, which may revolutionise the design of micro-machines, a new report says.

Physicists said they can create "incredible levitation effects" by manipulating so-called Casimir force, which normally causes objects to stick together by quantum force.

The phenomenon could be used to improve the performances of everyday devices ranging from car airbags to computer chips, say Professor Ulf Leonhardt and Dr Thomas Philbin from Saint Andrews University.

Casimir force -- discovered in 1948 and first measured in 1997 -- can be seen in a gecko's ability to stick to a surface with just one toe.

Now the British scientists say they can reverse the Casimir force to cause an object to repel rather than attract another in a vacuum.

"The Casimir force is the ultimate cause of friction in the nano world, in particular in some micro-electromechanical systems," said Leonhardt, writing in the August issue of New Journal of Physics.

"Micro or nano machines could run smoother and with less or no friction at all if one can manipulate the force," he added.

And he added: "In order to reduce friction in the nanoworld, turning nature's stickiness into repulsion could be the ultimate remedy. Instead of sticking together, parts of micromachinery would levitate."

Leonhardt stressed that the practise is possible only for micro-objects.

But he underlined that, although in principle it may one day be possible to levitate humans, that day is a long way off.

"At the moment, in practice it is only going to be possible for micro-objects with the current technology, since this quantum force is small and acts only at short ranges," he said.

"For now, human levitation remains the subject of cartoons, fairytales and tales of the paranormal."

Their research was to be published in the New Journal of Physics.

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Blog History

The term "weblog" was coined by Jorn Barger on 17 December 1997. The short form, "blog," was coined by Peter Merholz, who jokingly broke the word weblog into the phrase we blog in the sidebar of his blog Peterme.com in April or May of 1999.[6][7][8] This was quickly adopted as both a noun and verb ("to blog," meaning "to edit one's weblog or to post to one's weblog").

After a slow start, blogging rapidly gained in popularity: the site Xanga, launched in 1996, had only 100 diaries by 1997, but over 20 million as of December 2005. Blog usage spread during 1999 and the years following, being further popularized by the near-simultaneous arrival of the first hosted blog tools: Open Diary l(aunched in October 1998), LiveJournal (in March 1999) and blogger.com (in August 1999).

The Cure for Insomnia

The Cure for Insomnia, is a movie directed by John Henry Timmis IV, is officially the world's longest movie, according to Guinness World Records, as of its release in 1987. Running 5220 minutes (87 hours) in length, the movie has no plot, instead consisting of artist L. D. Groban reading his lengthy poem "A Cure for Insomnia" over the course of three and a half days, spliced with occasional clips from heavy metal and pornographic videos.

The movie is shot entirely on video, and its intended purpose actually was to be so unbelievably boring that it would put people to sleep thus curing insomnia. It is therefore disputed as to whether or not The Cure for Insomnia should even be considered as a candidate for the world's longest film in the strictest sense.

It was first played in its entirety at The School of the Art Institute in Chicago, Illinois from January 31 to February 3, 1987 in one continuous showing. It is not clear whether or not the movie has been shown since then. Considering that a DVD can only hold up to five hours of video at poor quality, The Cure for Insomnia would fill around 18 discs.

Rises of the machine

This man story began, six years ago. One night, in a robbery while walking home, He was beaten and left for dead. His skull was crushed and his brain severely damaged. The doctor said if he pulled through at all, he'd be a vegetable for the rest of his life. The man could not speak or eat.On occasion he showed signs of awareness, and he moved his eyes or a thumb to communicate. His arms were useless. He was fed through a tube.

But researchers chose him for an experimental attempt to rev up his brain by placing electrodes in it. And here's how his mother describes the change in her son, now 38:

"My son can now eat, speak, watch a movie without falling asleep," she said Wednesday while choking back tears during a telephone news conference. "He can drink from a cup. He can express pain. He can cry and he can laugh.

"The most important part is he can say, `Mommy' and `Pop.' He can say, `I love you, Mommy' ... I still cry every time I see my son, but it's tears of joy."

The progress of the patient, who remains unidentified at the family's request, is described more formally in a report in Thursday's issue of the journal Nature.

Experts called the results encouraging but cautioned that the experimental treatment must be tried in more patients before its value can be assessed. The researchers are already proceeding with a larger study.

Before the electrodes were implanted, the man was in what doctors call a "minimally conscious state." That means he showed only occasional awareness of himself and his environment. In a coma or vegetative state, by contrast, patients show no outward signs of awareness.

There are no reliable statistics on how many Americans are in a minimally conscious state, but one estimate suggests 112,000 to 280,000. Doctors may try medications to improve their condition but no drugs have been firmly established as helpful.

The experimental treatment is called deep brain stimulation. It has been used for years in treating Parkinson's disease, although in this case the electrodes were implanted in slightly different places. The goal of the stimulation was to provide "drive" to areas of the brain that are critical for specific skills like speaking.

Similar stories of partial recovery from brain damage occasionally grab headlines, whether the improvement came from treatment or just out of the blue.

Terry Wallis of Arkansas lingered in a minimally conscious state for almost 20 years before he suddenly regained some ability to speak and move in 2003. In 2005, a former firefighter in Buffalo, N.Y., turned from being barely aware and almost mute for nearly a decade into a virtual chatterbox for 14 hours. His doctor had been trying a cocktail of drugs.

The man described in the Nature paper, despite his improvements, remains severely disabled in a rehabilitation facility for brain injury on the East Coast. (To preserve the man's anonymity, the researchers would not identify the facility or even reveal which state it is in).

He can't walk. While he has regained the ability to chew and swallow, he must be spoon-fed. He can demonstrate the motion of brushing his teeth, for example, but he can't actually do it. That's because tendons in his arms contracted after years of immobility, said study lead author Dr. Nicholas Schiff of Weill Cornell Medical College in New York.

The man doesn't initiate conversation but can reply to others, generally with one to three words, said Dr. Joseph Giacino, a co-lead author of the Nature study.

Several weeks ago, he recited the first half of the Pledge of Allegiance without assistance, said Giacino, of the JFK Johnson Rehabilitation Institute in Edison, N.J.

The man's electrodes are left on for 12 hours a day. He has continued to improve since the experiment formally ended in February 2006, the doctors said.

After the research was over, doctors started giving him the drug amantadine, which has shown some potential for treating people in a minimally conscious state. It's not clear whether amantadine can boost the effects of deep brain stimulation or vice versa, Giacino said.

Dr. James Bernat, a professor of neurology at Dartmouth Medical School who didn't participate in the new research, called the Nature report exciting and important. Further study is needed to sort out how many patients would respond and how to identify the minimally conscious patients with the best chance of being helped, he said.

He noted that a similar treatment did not help Terri Schiavo, the Florida woman in a vegetative state whose care triggered national controversy before her death in 2005. That's the typical outcome for electrical brain stimulation in vegetative states, he said.

Dr. Ross Zafonte of the University of Pittsburgh, who also was familiar with the study results, agreed that "we need to know more." He said the approach is "very interesting and holds great promise."

Seeing like a fish

The ability of zebrafish to regenerate damaged retinas has given scientists a clue about restoring human vision and could lead to an experimental treatment for blindness within five years.

British researchers said on Wednesday they had successfully grown in the laboratory a type of adult stem cell found in the eyes of both fish and mammals that develops into neurons in the retina.

In future, these cells could be injected into the eye as a treatment for diseases such as macular degeneration, glaucoma and diabetes-related blindness, according to Astrid Limb of University College London's (UCL) Institute of Ophthalmology.

Damage to the retina -- the part of the eye that sends messages to the brain -- is responsible for most cases of sight loss.

"Our findings have enormous potential," Limb said. "It could help in all diseases where the neurons are damaged, which is basically nearly every disease of the eye."

Limb and her colleagues studied so-called Mueller glial cells in the eyes of people aged from 18 months to 91 years and found they were able to develop them into all types of neurons found in the retina.

They were also able to grow them easily in the lab, they reported in the journal Stem Cells.

The cells have already been tested in rats with diseased retinas, where they successfully migrated into the retina and took on the characteristics of the surrounding neurons. Now the team is working on the same approach in humans.

"We very much hope that we could do autologous transplants within five years," Limb told Reuters.

Autologous transplants, initially on a trial basis, will involve manipulating cells and injecting them back into an individual's own eye. Eventually, Limb hopes it will also be possible to transfer the cells between different people.

"Because they are so easy to grow, we could make stem cell banks and have cell lines available to the general population, subject to typing as with blood transfusions," she said.

Just why zebrafish have an abundant supply of adult stem cells to regenerate their retinas, while they are rare in mammals, remains a mystery but Limb suspects it is because mammals have a limiting system to stop proliferation.

The new work on Mueller glial cells is the latest example of researchers exploring the potential of different kinds of stem cells in treating eye disease. Another team from UCL and Moorfield's Eye Hospital said in June they aimed to repair damaged retinas with cells derived from embryonic stem cells.


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