Dhaka, Mar 13 (UNB) - Scientists have reversed the direction of time with a quantum computer, reports Independent.

The breakthrough study seems to contradict basic laws of physics and could alter our understanding of the processes governing the universe.

In a development that also represents a major advance in our understanding of quantum computers, by using electrons and the strange world of quantum mechanics, researchers were able to turn back time in an experiment that is the equivalent of causing a broken rack of pool balls to go back into place.

Anyone watching the computer would see the event as if time had turned backwards.

The researchers – from the Moscow Institute of Physics and Technology and helped by colleagues in Switzerland and the US – expect the technique to improve in time, becoming more reliable and precise with time.

Lead researcher Dr Gordey Lesovik, who heads the Laboratory of the Physics of Quantum Information at the Moscow Institute of Physics & Technology (MIPT), said: "We have artificially created a state that evolves in a direction opposite to that of the thermodynamic arrow of time."

The "time machine" described in the journal Scientific Reports consists of a rudimentary quantum computer made up of electron "quabits".

A qubit is a unit of information described by a "one", a "zero", or a mixed "superposition" of both states.

In the experiment, an "evolution program" was launched which caused the qubits to become an increasingly complex changing pattern of zeros and ones.

During this process, order was lost – just as it is when the pool balls are struck and scattered with a cue.

But then another program modified the state of the quantum computer in such a way that it evolved "backwards", from chaos to order.

It meant the state of the qubits was rewound back to its original starting point.

Most laws of physics work both ways, in the future and the past. If you see a video of a pool ball knocking into another one, for instance, and then reverse that same video, the physical processes would both make sense and it would be impossible at the level of physics to know which way around would be correct.

But the universe does have one rule that goes only in one way: the second law of thermodynamics, which describes the progression from order to disorder.

If you saw a video of someone breaking a perfectly arranged triangle of pool balls into a mess, for instance, then watching that backwards would obviously look nonsensical.

The new experiment is like giving the pool table such a perfectly calculated kick that the balls rolled back into an orderly pyramid.

The scientists found that, working with just two qubits, "time reversal" was achieved with a success rate of 85 per cent. When three qubits were involved more errors occurred, resulting in a 50 per cent success rate.

The error rate is expected to drop as scientists improve the devices used to be more sophisticated, the researchers behind the discovery said.

The experiment could have a practical application in the development of quantum computers, the scientists said.

"Our algorithm could be updated and used to test programmes written for quantum computers and eliminate noise and errors," said Dr Lesovik.

Cape Canaveral, Mar 3 (AP/UNB) — SpaceX's new crew capsule arrived at the International Space Station on Sunday, acing its second milestone in just over a day.

No one was aboard the Dragon capsule launched Saturday on its first test flight, only an instrumented dummy. But the three station astronauts had front-row seats as the sleek, white vessel neatly docked and became the first American-made, designed-for-crew spacecraft to pull up in eight years.

TV cameras on Dragon as well as the space station provided stunning views of one another throughout the rendezvous.

If the six-day demo goes well, SpaceX could launch two astronauts this summer under NASA's commercial crew program. Both astronauts — Doug Hurley and Bob Behnken — were at SpaceX Mission Control in Southern California, observing all the action. They rushed there from Florida after watching the Dragon rocket into orbit early Saturday from NASA's Kennedy Space Center.

"Just super excited to see it," Behnken said minutes after the link-up. "Just one more milestone that gets us ready for our flight coming up here."

While SpaceX has sent plenty of cargo Dragons to the space station, crew Dragon is a different beast. It docked autonomously under the station astronauts' watchful eyes, instead of relying on the station's robot arm for berthing. Behnken said that's the way it should work when he and Hurley are on board; they may push a button or two and will have the ability to intervene, if necessary.

As part of Sunday's shakedown, the station astronauts sent commands for the Dragon to retreat and then move forward again, before the capsule closed in for good.

SpaceX employees at company headquarters in Hawthorne, California, cheered and applauded as crew Dragon pulled up and docked at the orbiting lab, nearly 260 miles (400 kilometers) above the Pacific, north of New Zealand. They burst into applause again, several minutes later, when the Dragon's latches were tightly secured.

The station astronauts offered congratulations to SpaceX, as they got ready to open the hatches and collect the supplies stashed aboard Dragon. The capsule's lone passenger — a mannequin wearing a white SpaceX spacesuit — also was going to be welcomed aboard. The test dummy — or Smarty as SpaceX likes to call it, given all the instrumentation — is named Ripley after the lead character in the science-fiction "Alien" films.

Dragon will remain at the space station until Friday, when it undocks and aims for a splashdown in the Atlantic, a couple hundred miles off the Florida coast.

Like Ripley, the capsule is rigged with sensors to measure noise, vibration and stresses, and to monitor the life-support, propulsion and other critical systems throughout the flight.

SpaceX aims to launch Behnken and Hurley as early as July.

Next up, though, should be Boeing, NASA's other commercial crew provider. Boeing is looking to launch its Starliner capsule without a crew as early as April and with a crew possibly in August.

NASA is paying the two private companies $8 billion to build and operate the capsules for ferrying astronauts to and from the space station. Astronauts have been stuck riding Russian rockets ever since NASA's space shuttle program ended in 2011. Russian Soyuz seats go for up to $82 million apiece.

Cape Canaveral, Feb 23 (AP/UNB) — NASA and SpaceX on Friday approved a first test flight next week of the new commercial Dragon capsule designed for crew.

No one will be aboard, only an instrumented dummy in a white SpaceX spacesuit. But the capsule will still fly to the International Space Station, following its planned March 2 liftoff from NASA's Kennedy Space Center.

Officials gave the green light after conducting a safety review.

NASA's head of human exploration and operations, William Gerstenmaier, called the upcoming test flight "an absolutely critical first step" to eventually putting astronauts on board.

A phenomenal amount of work has gone into ensuring the capsule does not endanger the space station and its three occupants as it pulls up and docks, Gerstenmaier said. It will remain at the orbiting lab just under a week before aiming for a splashdown in the Atlantic off Florida. Radiation monitors and supplies are going up, and science samples and used equipment are coming down.

Human spaceflight is the company's core mission, said Hans Koenigsmann, a SpaceX vice president, and for now, there's nothing more important than this endeavor.

"It's a really big deal for SpaceX," he told reporters.

Space X has been making space station shipments since 2012. The private company had to overhaul its cargo capsule for astronauts. If the upcoming demo goes well, two NASA astronauts could strap in for the next test flight this summer. Officials stressed much work remains to be done, with problems possibly solved through redesign, before the capsule is qualified to carry humans.

It would be the first launch of NASA astronauts from U.S. soil in eight years, since NASA's shuttle program ended. They have been riding Russian rockets to get to and from the space station, costing NASA tens of millions of dollars per seat.

The SpaceX Falcon 9 rocket scheduled to soar at 2:48 a.m. EST on March 2 is brand new. NASA does not want recycled boosters for these crew capsule missions. SpaceX plans to conduct a high-altitude launch abort in April, reusing this same capsule.

Boeing is also in the commercial race to transport space station astronauts. Its first Starliner demo is targeted for April, and the second, with astronauts, no earlier than August.

Washington, Feb 19 (Xinhua/UNB) - An international team of scientists have decoded the entire genome of white shark and identified their superior cancer-protective abilities.

The study published on Monday in the the journal Proceedings of the National Academy of Sciences showed that a plethora of genetic changes might be behind the evolutionary success of large-bodied and long-lived sharks.

The researchers found that the massive vertebrate's molecular adaptation in numerous genes helped maintain the genome stability and counteract the accumulation of damage to a species' DNA, thereby preserving the integrity of the genome.

The opposite phenomenon called genome instability, which results from accumulated DNA damage, is well known to expose humans to numerous cancers and age-related diseases, according to the study.

"Not only were there a surprisingly high number of genome stability genes that contained these adaptive changes, but there was also an enrichment of several of these genes, highlighting the importance of this genetic fine-tuning in the white shark," said Mahmood Shivji with Nova Southeastern University, who led the study.

Previously, scientists supposed that the risk of developing cancer should increase with both the number of cells (large bodies) and an organism's lifespan. The white shark has a huge size of genome, one-and-a-half times the size the the human genome.

But contrary to the expectation, the new study found that very large-bodied animals did not get cancer more often than humans.

The study showed that the white shark genome contained a very high number of "jumping genes" or transposons, which could represent a strong selective agent for the evolution of efficient DNA repair mechanisms.

Shivji's group also found evolutionary adaptations were linked to the white shark's rapid wound healing ability.

"Genome instability is a very important issue in many serious human diseases. Now we find that nature has developed clever strategies to maintain the stability of genomes in these large-bodied, long-lived sharks," said Shivji.

Shivji said the findings might be useful to fight cancer and age-related diseases, and improve wound healing treatments in humans.

Cape Canaveral, Feb 13 (AP/UNB) — NASA is trying one last time to contact its record-setting Mars rover Opportunity, before calling it quits.

The rover has been silent for eight months, victim of one of the most intense dust storms in decades. Thick dust darkened the sky last summer and, for months, blocked sunlight from the spacecraft's solar panels.

NASA said Tuesday it will issue a final series of recovery commands, on top of more than 1,000 already sent. If there's no response by Wednesday — which NASA suspects will be the case — Opportunity will be declared dead, 15 years after arriving at the red planet.

Team members are already looking back at Opportunity's achievements, including confirmation water once flowed on Mars. Opportunity was, by far, the longest-lasting lander on Mars. Besides endurance, the six-wheeled rover set a roaming record of 28 miles (45 kilometers.)

Its identical twin, Spirit, was pronounced dead in 2011, a year after it got stuck in sand and communication ceased.

Both outlived and outperformed expectations, on opposite sides of Mars. The golf cart-size rovers were designed to operate as geologists for just three months, after bouncing onto our planetary neighbor inside cushioning air bags in January 2004. They rocketed from Cape Canaveral a month apart in 2003.

It's no easier saying goodbye now to Opportunity, than it was to Spirit, project manager John Callas told The Associated Press.

"It's just like a loved one who's gone missing, and you keep holding out hope that they will show up and that they're healthy," he said. "But each passing day that diminishes, and at some point you have to say 'enough' and move on with your life."

Deputy project scientist Abigail Fraeman was a 16-year-old high school student when Opportunity landed on Mars; she was inside the control center as part of an outreach program. Inspired, Fraeman went on to become a planetary scientist, joined NASA's Jet Propulsion Laboratory in Pasadena, California, and ended up deputy project scientist for Opportunity.

"It gives you an idea just how long this mission has lasted," she said. "Opportunity's just been a workhorse ... it's really a testament, I think, to how well the mission was designed and how careful the team was in operating the vehicle."

Rather than viewing the dust storm as bad luck, Callas considers it "good luck that we skirted so many possible storms' over the years. Global dust storms typically kick up every few years, and "we had gone a long time without one." Unlike NASA's nuclear-powered Curiosity rover still chugging along on Mars, Opportunity and Spirit were never designed to endure such severe weather.

Cornell University's Steve Squyres, lead scientist for both Opportunity and Spirit, considers succumbing to a ferocious storm an "honorable way" for the mission to end.

"You could have lost a lot of money over the years betting against Opportunity," Squyres told the AP Tuesday.

The rovers' greatest gift, according to Squyres, was providing a geologic record at two distinct places where water once flowed on Mars, and describing the conditions there that may have supported possible ancient life.

NASA last heard from Opportunity on June 10. Flight controllers tried to awaken the rover, devising and sending command after command, month after month. The Martian skies eventually cleared enough for sunlight to reach the rover's solar panels, but there was still no response. Now it's getting colder and darker at Mars, further dimming prospects.

Engineers speculate the rover's internal clock may have become scrambled during the prolonged outage, disrupting the rover's sleep cycle and draining on-board batteries. It's especially frustrating, according to Callas, not knowing precisely why Opportunity — or Spirit — failed.

Now it's up to Curiosity and the newly arrived InSight lander to carry on the legacy, he noted, along with spacecraft in orbit around Mars.

As for Opportunity, "It has given us a larger world," Callas said. "Mars is now part of our neighborhood."