Aerial performer Jennifer Bricker was born without legs, but she never let it stop her.

    Wrapped in a loop of red silk hung from the ceiling Jennifer Bricker climbs and twists to the music. Her head hangs down and her strong arms let go as she balances on her back, high above the ground a move that's all the more daring because she has no legs.

    Jennifer was a few months old when she was adopted by Sharon and Gerald Bricker. She had big brown eyes, a bright smile, and huge amounts of energy. When a doctor advised her adoptive parents to carry her around in a kind of bucket, they refused.

    Jennifer soon learned to walk — and run — on her hands and bottom, and grew up fearlessly climbing trees and bouncing on the trampoline（蹦床） with her three older brothers. “My parents didn't treat me differently so I didn't grasp the concept that I was different. I knew I didn't have legs but that wasn't stopping me from doing the things I wanted to do.”

    At the age of three she was fitted with artificial legs, but she never really took to them — she moved more freely without.

    In 1996 the Olympic Games took place in Atlanta. Jennifer loved to watch the women's gymnastics team, and especially adored the 14-year-old Dominique Moceanu who competed for the US. When Moceanu and the women's team won gold, Jennifer decided she was going to be a gymnast, too. She took up power tumbling, which involves performing floor exercises down a runway. But Jennifer did not want any allowances to be made for her disability.

    At the age of 10 she took part in the Junior Olympics and by age 11 she was tumbling champion for the state of Illinois.

    Jennifer now travels the world as an inspirational speaker and acts as an aerial performer.

    In 1905, as part of his Special Theory of Relativity, Albert Einstein published the point that a large amount of energy could be released from a small amount of matter. This was expressed by equation E = me 2(energy = mass times the speed of light squared). But bombs were not what Einstein had in mind when he published this equation.

    In 1929, he publicly declared that if a war broke out he would “refused to do war service, direct or indirect…” His position would change in 1933, as the result of Adolf Hitler's coming into power in Germany.

    Einstein's greatest role in the invention of the atomic bomb was signing a letter to President Franklin Roosevelt urging that the bomb be built because some physicists feared that Germany might be working on an atomic bomb. Among those concerned were physicists Leo Szilard and Eugene Wigner. But Szilard and Wigner had no influence with those in power. So in July 1939 they explained the problem to someone who did: Albert Einstein. After talking with Einstein, in August 1939 Szilard wrote a letter to President Roosevelt with Einstein's signature on it, which was delivered to Roosevelt in October 1939.

    Germany has invaded Poland the previous month; the time was ripe for action. That October research of a-bomb began but proceeded slowly because the invention of the atomic bomb seemed distant and unlikely. In April 1940 an Einstein letter, ghost-written by Szilard, pressed the researchers on the need for “greater speed”.

    As the realization of nuclear weapons grew near, Einstein looked beyond the current war to future problems that such weapons could bring. He wrote to his friend about his fear about the future use of the a-bomb.

    The atomic bombings of Japan occurred three months after Germany gave in.

In November 1954, five months before his death, Einstein summarized his feelings about his role in the creation of the atomic bomb: “I made one great mistake in my life… when I signed a letter to President Roosevelt recommending that atom bombs be made; but there was some justification— the danger that the Germans would make them”.

    Car companies are developing vehicles that will plug into electric sockets, ust like many laptops, digital cameras, cell phones and Mp4 do. Called “plug-in vehicles”, these cars will get most of their power from electricity. Their drivers won't have to stop at gas stations as often as usual.

    The technology is more than just cool. In our car-filled world, plug-in vehicles could reduce the amount of gas we use, which keeps rising in cost now and then. Besides, driving around in these vehicles may even help the environment. Gas-burning cars produce a lot of greenhouse gas, which causes global warming.

    The first company-produced plug-in vehicles could hit the roads by 2020. But engineers still have a lot of work to do to make the technology practical and inexpensive.

    Batteries are the biggest challenge. In the plug-in-vehicle world，Li-ion(锂离子)batteries are getting the most attention. These batteries can store a large amount of energy in a small package, and they last a longer time between charges. Li-ion batteries can fit laptops, cell phones, heart instruments and other similar pocket ones.

    But because cars are so big and heavy, it would still require a suitcase-sized Li-ion batteries to power about 12km of driving. What's more, the batteries are much expensive.

    “A car filled with batteries could go a long distance,” says Ted Bohn, an electrical engineer in Chicago. “But it couldn't pull any people, and it would cost $100,000.” So researchers need to work out how to make batteries smaller and cheaper, among other questions.

    “The answers don't exist yet,” Bohn says, “As a kid, I thought someone someplace knows the answer to everything. All of these questions haven't been decided. That's what engineering is about-making a guess, running tests and getting fine results.”

    The vast majority of us spend our entire lives pulled down by gravity. Then there are astronauts.

This small population of space travelers has given researchers a rare look at what happens to the human body when it's able to spend large amounts of time outside the downward pull of the Earth. This week, a study on one of the largest groups of astronauts yet —34 participants—was published in The New England Journal of Medicine.

    In the new study, a team of international radiologists supported by NASA looked at MRIs of the brains of astronauts before and after their trips to space. The scientists found that upon returning to Earth, many of the astronauts' brains had become repositioned inside their skulls, floating higher than before. In addition, the space between certain brain areas appeared to have shrunk. The changes were more common in astronauts who took longer trips into space.

    The team characterized astronaut trips as short (an average of less than 14 days) or long (an average of about 165 days). Radiologists who didn't know each astronaut's duration（持续时间）in space compared MRIs from before and after their trips.

    Of the 34 total astronauts involved in the study, 18 took long trips to space—spending most of that time on the International Space Station —and of those, 17 returned to Earth with smaller areas between the frontal lobe（脑前额叶）and parietal lobe（顶叶）. The same area of the brain also shrank for three of the 16 astronauts who took shorter trips with the US Space Shuttle Program. The researchers also found that 12 of the ISS astronauts and six of the space-shuttle astronauts returned home with their brains sitting slightly higher in their skulls than before.

    It's not clear what, if anything, these brain changes mean for the health of space travelers. In general, it appears the human body tolerates space travel fairly well: the time astronauts have spent in zero-gravity environments so far doesn't seem to have had any strong or long-lasting effects.

    Five thousand square meters of old damaged cars, motorcycles and boats fill this junkyard. For a casual onlooker, this might be a very sad sight. But for Andy, it's a real treasure. "I've been a junk hoarder (囤积者) for my whole life and I like fixing up what shouldn't be thrown away. Around 200 old cars end up in this junkyard every week. Some of them are sold for parts, others get repaired, and still others are beyond repair."

    His father Bobby started the business some 50 years ago and still spends every morning there. The father and son have very different approaches to their work. They got a Dean cab that was getting thrown away and that was the father's project, which Andy did not want him to do. "He did basically the opposite of everything I told him and I think he did it just to make me mad. He dumped a ton of money into this car, but in the end it wouldn't run." Andy said jokingly.

    The unusual family business attracted the attention of a TV crew. That's how the show Janka Empire came to be featured on a network of the Discovery Channel. This show, five years of shooting, five seasons and 60 episodes (集), is popular. "There are hundreds of junkyards throughout the United States. I think what's interesting is that it is a family business. My father and I started the business and we joke very well back and forth and I think that's what people like. The cars that end up at the junkyard come out with endless surprises. See, this was a junk car and we restored it with a blown motor. Yet I don't get a chance to ride around it too often. Because despite its shining appearance, the noise of the engine is truly deafening and I worry my neighbors will not put up with it."

    Schoolgirl Lorna O'Brien was in her kitchen when she looked out of the window and was terrified (惊恐的) at what she saw. "Help!" she shouted. "There's smoke and fire coming out of the kitchen window opposite."

    Her father, John, ran across to the house while her 15­year­old brother Paul called the fire service. Lorna, 16, rushed across and caught up with her dad, who had just kicked open the front door. They looked upstairs where they saw smoke coming out of the top flat. Lorna followed her father into the flat, where they found a pan (平底锅) on fire in the kitchen and the young mother, Mane Linn, who had been asleep, passed out (失去意识) in the smoke­blackened sitting room. Lorna's dad threw a wet cloth over the pan and then turned off the stove (炉子) before starting to help Mane through the smoke down the stairs to safety.

    Suddenly Mane started crying, "My baby, my baby!" "Where's the baby?" asked Lorna. "In the bedroom," Mane shouted back. While John pulled the crying mother from the house, Lorna, without a thought for her own safety, turned back to search for the baby. She found the little girl, 14­month­old Ann, lying with her eyes closed.

    Lorna quickly took the baby, rushed downstairs through the fire and smoke. "It didn't cross my mind at the time that I was near to dying when I rushed through the smoke，" said Lorna. "I was just thinking of the baby. Even after I came out of the house, I wasn't frightened."

    When help arrived, baby Ann and her mum were taken to hospital for treatment. It was only when Lorna got back into the safety of her own house that she realised the danger she had faced. "I started shaking all over and thought of what could have happened to me，" she said.