Most people know that Marie Curie was the first woman to win the Nobel Prize, and the first person to win it twice. However, few people know that she was also the mother of a Nobel Prize winner.

    Born in September, 1987, Irene Curie was the first of the Curies' two daughters. Along with nine other children the parents of whom were also famous scholars, Irene studied in their own school, and her mother was one of the teachers. She finished her high school education at the College of Sévigné in Paris.

    Irene entered the University of Paris in 1914 to prepare for a degree in mathematics and physics. When World War I began, Irene went to help her mother, who was using X-ray facilities (设备) to help save the lives of wounded soldiers. Irene continued the work by developing X-ray facilities in military hospitals in France and Belgium. Her services were recognised in the form of a Military's Medal by the French government.

    In 1918, Irene became her mother's assistant at the Curie Institute. In December 1924, Frederic Joliot joined the Institute, and Irene taught him the techniques required for his work. They soon fell in love and were married in 1926. Their daughter Helene was born in 1927 and their son Pierre five years later.

    Like her mother, Irene combined family and career. Like her mother, Irene was awarded a Nobel Prize, along with her husband, in 1935. Unfortunately, also like her mother, she developed leukemia because of her work with radioactivity (辐射能). Irene Joliot-Curie died from leukemia on March 17, 1956.

    Crown shyness (树冠羞避) is a mysterious natural phenomenon in which the crowns of some tree species do not touch each other, but get separated by a gap clearly seen from ground level. The effect usually occurs between trees of the same species, but has also been observed between trees of different species.

    There are many theories going around, most of which make sense, but no one has been able to prove without the shadow of a doubt why some trees avoid touching each other.

    In his 1955 book Growth Habits of the Eucalypts, Australian forester M. R. Jacobs writes that the growing tips of the trees are sensitive to abrasion (擦伤), which results in crown shyness phenomenon. This theory was also supported by Dr. Miguel Franco. Some experiments have shown that if trees displaying crown shyness are artificially prevented from swaying (摇摆)in the wind and touching each other, they gradually fill up the gaps between them.

    But while the above theory is arguably the most widespread, it's certainly not the only one. Some scientists have suggested that crown shyness is a mechanism to stop the spreading of leaf-eating insects. The gaps mean pests wouldn't be able to reach other trees, so they are the tree's natural defense method.

    One Malaysian scholar studied many trees, but found no traces of abrasions, despite their clear crown shyness. Instead, he suggests that the growing tips of the trees were sensitive to light levels and stopped growing when they got too close to other trees. Plants are able to sense how close they are to other plants and in order to get more light, they give off some chemical to stop other trees from growing too close.

    Whatever the reason, one thing is for sure, plants are more intelligent than people.

    One of the most exciting and interesting international cities to visit is London, England. Here is a look at four free things to do during a vacation to London.

    Visit the Trafalgar Square

    Built more than 200 years ago, Trafalgar Square is a popular gathering place for locals and travelers, too. The area is close to good shopping and dining opportunities, and there are usually some sorts of public events or celebrations going on there during most weekends.

    Wander Along the Thames

    Visitors wanting to sec some great architecture, attractions and views should spend an afternoon walking along the River Thames. The best place to start is at the world-famous London Bridge crossing over the river and you can walk all the way to Westminster Bridge a short distance away. Travelers doing this will find themselves passing by a great many historic buildings.

    Explore the Local Markets

    While purchasing items at any of the open markets in London is not necessarily free, walking through them to view the merchants（商人）, their products and the other shoppers is of great fun. Some of the popular open markets in London worth visiting include Spitafields Market, Portobello Road Market and Leadenhall Market.

     Visit the British Museum

    One of the top museums in the entire United Kingdom can be found in London, and it charges no admission（人场费）for entry. This museum is so highly regarded that it is not only popular with locals and tourists, it is also seen as a major and valuable scholarly resource.

    There has long been a notion （观念） that money buys happiness. However, although "we really, really tried that for a couple of generations, it didn't work," said Francine Jay, author of The Joy of Less, A Minimalist Living Guide: How to Declutter, Organize, and Simplify Your Life.

    Thanks to a travel inspired revelation （启发）, Jay has been happily living a simpler life for 12 years. "I always packed as lightly as possible, and found it exciting to get by with just a small carry on bag," she told CNN. "I thought if it feels this great to travel lightly, how amazing would it be to live this way？ I wanted to have that same feeling of freedom in my everyday life."

Jay decided to get rid of all her excess （额外的） possessions and live with just the essentials （必需品）. "I wanted to spend my time and energy on experiences, rather than things."

    Jay is a follower of a movement called "minimalism （极简主义）". Growing numbers of people have been attracted to this lifestyle all over the world. They share the same feeling of disappointment with modern life and a desire to live more simply. Minimalists are typically progressive and concerned about the environment, Leah Watkins, a lead researcher at Ota go University in New Zealand, told Stuff magazine in March.

    But many simply experienced unhappiness caused by owning too many possessions. Depression with the materialism of our world isn't new. English romantic poet William Wordsworth summed up how dispiriting （令人消沉的） this was back in 1802, at the beginning of the industrial age, when he wrote: "Getting and spending, we lay waste our powers". His preference was to go back to nature. Closer to our own times, the hippies （嬉皮士） of the 1960s also sought to "drop out" of modern life.

    And for many minimalists, their key is to unload. Without objects, they "believe people are forced more and more into the present moment and that's where life happens," wrote Stuff.

But does simplicity ever feel like a sacrifice （牺牲）？

    "It's eliminating the excess﹣unused items, unnecessary purchases﹣from your life. Well, I may have fewer possessions, but I have more space …Minimalism is making room for what matters most," said Jay.

    And "the real questions", according to Duane Elgin, US social scientist, are "what do you care about？" and "What do you value?"

    He told CNN: "It's important for people to realize minimalism isn't simply the amount of stuff we consume. It's about our families, our work, our connection with the larger world, our spiritual dimension. It's about how we touch the whole world. It's a way of life."

    Welcome to Hawks Cay Resort

    Centrally lying between Miami and key west, Hawks Cay Resort offers the perfect union of solitude and convenience. Here you can enjoy the best qualities of the Caribbean-clear green waters, endless sunshine, excellent fishing and diving chances, and fresh seafood.

    THE MIDDLE OF EVERYTHING

    Hanks Cay lies in the middle of the Florida Keys on the quiet island of Duck Key. The resort is just over an hour's drive from Key West attractions, and only minutes from the village of Marathon where you'll find the Seven-Mile Bridge, the Marathon Turtle Hospital, shopping changes and more.

    GETTING TO HAWKS CAY RESORT

    By Land

    Drive the Overseas Highway, awarded one of America's most scenic roads, as you travel across historic fishing bridges, and admire the blue and green water of the Atlantic Ocean and Florida Bay. Hawks Cay centrally lies only 90 miles by car from Miami and 130 miles from Fort Lauderdale. Cars can be rented from Marathon Airport, lying just a few miles from the resort.

    By Air

    Daily flights are offered into nearby Miami, Fort Lauderdale/Hollywood and Key West International airports. Hawks Cay is proud to partner with the Marathon Jet Center, lying just 9 miles from the resort, offering lights and private jet service.

    Fly direct to Marathon International Airport from Fort Lauderdle, Miami, Marco Island and Naples for as low as $222 per person one way. Flight time is approximately 38 minutes.

    By Sea

    Hawks Cay can easily be reached via the Atlantic Ocean or Gulf of Mexico. Hawks Cay's full-service marina features fees for ships up to 110 feet, and all the boating and fishing supplies you'll need during your stay in the beautiful Florida Keys.

    Gregory Kloehn digs through dustbins every day, but not for the reason that most people would think. He isn't homeless. In fact he is trying to help the homeless.

    Gregory began his life as a sculptor. But he often felt that his sculpture (雕塑) which just stood in rich people's houses for years, lacked a meaningful purpose. So in 2015 he decided to put his artistic energies into creating homes to sell—not ordinary homes but small structures built entirely from recycled materials.

    The thought of creating homes for the homeless didn't come to him until the year 2017, when a homeless couple asked him for a tarp (防水布). Instead of a tarp, Gregory offered them something better: a small home with a water tank, a kitchen and a tap for waste. They were so grateful that Gregory decided to focus his efforts on helping house the homeless population in his city. And soon his "Homeless Homes Project" was started.

    Before starting a new home, Gregory goes hunting for materials by digging through dustbins. Everything he finds is usable—refrigerator doors become house doors; washing machine doors often serve as windows, and the tops of cars become strong roofs. He put wheels at the bottom for users to move their homes around easily. Each home takes two to three days to make.

    So far Gregory has donated dozens of homes to the city's most needy. While his small low- cost mobile homes are not the final solution to the problem of homelessness, they are really practical and do provide a warm and safe place for the homeless to stay in. They are simply a way for one man to do something nice for those in need of some help.

    Gregory has written a book titled Homeless Architecture, where he explains techniques to build those homes and he is now working on weekend workshops. "A lot of people who hear about what I'm doing want to get involved," he said. "Maybe we can meet someplace and put a couple of homes together."