How long has 3-D technology been around? Most of us might think of crowds of teenagers in a 1950's movie house watching Bwana Devil in 3-D. But 3-D technology made its first appearance on the scene in 1838 with the first stereoscope(体视镜). And the first actual 3-D movie was a 1903 film called Le Ariveed'un Train.

    Although it has such a long history, the technology has still remained based on one simple principle—to make 3-D effects you must find a way to project two slightly different pictures to each eye. Modern 3-D technology works by rapidly flickering(闪动)two versions of the movie and projecting them onto each eye. The brain does the rest of the work, combining the two pictures together into one and giving the show the appearance of depth, the third dimension.

    But does this exposure, especially long exposures, cause harm to the child's developing brain and visual system? Unfortunately, long-term studies on new flicker digital 3-D technology and children aren't yet available. We do not know if regular or daily 3-D viewing over years affects the developing visual system, although older 3-D methods basically do the same thing and are not considered harmful.

    The question of possible harm in modern 3-D use in TV is really based on two facts: the amount of time children will now be watching 3-D TV each day and the sensitivity some children show in reaction to 3-D viewing. It is difficult to make actual lab studies of longer term 3-D viewing in children because of the possible harm of the experiment. Researchers will have to wait until 3-D TV technology is already in the marketplace for a number of years, then check heavy 3-D TV watchers and compare them with non-watchers.

    With a 3-D television technology in the home, we will soon be able to answer the question of whether or not longer and more frequent periods of 3-D exposure cause more changes in the visual system. We may find that the bigger problem is the introduction of a new technology that leads to even more time spent on TV rather than playing outdoors.

    There are an unbelievable number of reasons to go to Greece; just like there are an unbelievable number of things to do once a traveler arrives there. Here is a look at just some of the great historical things to see when on holiday in Athens, Greece.

    Agora

    Agora lies in ruins now, but during its glory days it was a lively and active open marketplace where Greeks came to buy, sell, and exchange their goods and services. Agora has ties to common people of ancient Greece.  Guided tours are available and there is also a small museum with many artifacts from this area on display.

    Parthenon

    One of the most famous landmarks in Athens is the legendary Parthenon. This building is still today admired by architects who are appreciative of the decorative design, as well as the engineering involved in its construction.  Those interested in history will be impressed beyond belief with the opportunity to see this historic structure up close and personal.

    Temple of Olympian Zeus

    One of the most impressive monuments to see up close is the Temple of Olympian Zeus. Many people see this monument from far away, or even from the window of a taxi, and never stop for a first hand look themselves. This is a huge mistake as the size of it cannot truly be appreciated without visiting it up close.

    Odeum of Herodes Atticus

    Built into the hillside and providing a nice view of Athens is the Odeum of Herodes Atticus. This theater was constructed in the second century and was an important gathering place for both the upper and lower classes. It holds a little over 5,000 people, is located just below the Acropolis, and is still used for performances to this day.

    It's common for children to grow up being told to minimize daydreaming, and instead to focus on lessons and class work. Historically, daydreaming students who go off on their own thoughts, rather than focusing on the teachers, the blackboard, or their class work, are often encouraged to stop allowing their attention to wander and to bring themselves back into the present moment. They're described as uninterested in school work and their future. Traditionally, daydreaming is seen as a practice that results in bad consequences.

    But recent studies are beginning to renounce those common beliefs by pointing out the potential benefits that daydreaming may provide. PsychCentral reports that Mary Smith, a psychological scientist and researcher, recently examined scientific writings and studies to gain a better understanding of the role of a reflective brain. These studies have shown that the brain has a network that is active when a person is daydreaming and that brain network can help memory and learning.

    Though paying attention in school is important, these results suggest that there should be time for students to daydream, too. Giving them the chance to reflect and daydream can help improve learning and development. Research also indicates that when students are permitted to daydream, they experience less anxiety and become more motivated. On the other hand, if students are warned against daydreaming, their knowledge of themselves and the world around them may suffer.

    As a result, educators are encouraged to promote a balance between outward and inward attention. A little bit of daydreaming to break up the hard focus on school activities can be beneficial, and it may help students become better, active learners.

    As for students, the lesson here is not to be afraid of doing some daydreaming. Sure, you want to pay attention to the vital information conveyed to you during your classes, but don't get discouraged if your mind wanders. A little bit of daydreaming is healthy.

    The last time I visited my eighty­three­year­old mother­in­law, I asked how she was feeling. It's a valid question. She has, after all, had two knee replacements and a liver transplant. She moves slowly to avoid another fall.

    But she hasn't stopped moving. She and my father­in­law attended their first Jimmy Buffet concert this summer. Here's the thing about my in­laws: They never say no to an invitation or a new adventure. If they can make it work, they're willing to try just about anything. When we need them to come to stay with the kids, we have to get on their calendars far in advance.

When asked how she was feeling, my motherinlaw responded, "Well, everything hurts every day. But you know what I've discovered? It doesn't hurt to smile. So that's what I've decided to do... smile at everyone I see. I may not be able to do all the things I used to do, but I can at least brighten someone's day."

    It is such simple wisdom. Moving the focus from what we don't have and from what we've lost to what we can offer others is the difference between living in the dark and radiating light. They inspire us daily.

    The key to a life worth living, I think, is to change our views. You don't have to make great changes. Sometimes change looks similar to everyday kindness. Sometimes change begins with holding the door for a mother with an armful of groceries.

    In theory, the butterfly effect says that the smallest breeze(微风) from a butterfly's wing can change the path of a hurricane halfway. Imagine, then, the possibilities that exist within a single smile.

    Siblings refer to one's brothers and sisters. We're attached to siblings as adults far longer than we are as children. Our sibling relationships, in fact, are the longest-lasting family ties we have.

    “Paul, my younger brother, and I, kind of annoyed each other when we were kids,” said Anna, an interviewee, “But as adults, we've always had each other's back, especially when dealing with our mother's health crisis. Paul is the first person I want to talk to when something worries me.”

    There's probably a biological explanation for the close bond of the sibling relationship. Siblings share half their genes, which biologists say should be motivation enough for each other's devotion.

    One thing that can weaken closeness in adulthood is a parent who played favorites in childhood; this sense of hatred can last a lifetime. The simple concept of parental favoritism was enough to shake their relationship.

    “What Paul and I are pretty sure is our parents treated us the same when we were growing up. Yet we're very different people,” Anna said,“ Paul is outgoing while I'm shy. Paul is an amateur pianist while I can't read music or carry a tune. In families with more than one child, every sibling seems to get a label in contrast to every other sibling.”

    The very presence of siblings in the household can be an education. When a new baby is born, the older sibling gains social skills by interacting with the younger, and the younger gains cognitively（认知角度地）by imitating the older. They learn from the friction between them, too, as they fight for their parents' attention. Mild conflict between brothers and sisters teaches them how to interact with friends and co-workers for the rest of their lives.

    It's so sad when things between siblings fall apart, which happens when aging parents need care or die — old feelings of contradiction and jealousy erupt all over again. Many families get through their parents' illnesses just fine, establishing networks where the workload is divided pretty much equally. But about 40 percent of the time there is a single primary caregiver who feels like she is not getting any help from her brothers and sisters, which can lead to serious conflicts.

    Throughout adulthood, the sibling relationship “is powerful and unchanged,” said Jane Mersky Leder, author of the new e-book The Sibling Connection. Whether we are close to our siblings or distant, she writes, they remain our brothers and sisters — for better or for worse.

    So remember the immortal（永恒的）words of folksinger Loudon Wainwright Ⅲ, in a song called Thanksgiving.“ On this brilliant occasion, this special family dinner, if I argue with a loved one, please make me…”

    You can't always predict a heavy rain or remember your umbrella. But designer Mikhail Belvacv doesn't think that forgetting to check the weather forecast before heading out should result in you getting wet.

    That's why he created Lampbrella, a lamp post with its own rain sensing umbrella.

    The designer says he came up with the idea after watching people get wet on streets in Russia. "Once, I was driving on a central Saint Petersburg street and saw the street lamps lighting up people trying to hide from the rain. I thought it would be appropriate to have a canopy(伞蓬) built into a street lamp," he said.

    The Lampbrella is a standard-looking street lamp fitted with an umbrella canopy. It has a built-in electric motor which can open or close the umbrella on demand. Sensors (传感器)then ensure that the umbrella offers pedestrians shelter whenever it starts raining.

    In addition to the rain sensor, there's also a 360 motion sensor on the fiberglass street lamp which detects whether anyone's using the Lampbrella. After three minutes of not being used the canopy is closed.

    According to the designer, the Lampbrella would move at a relatively low speed, so as not to cause harm to the pedestrians. Besides, it would be grounded to protect from possible lighting strike. Each Lampbrella would offer enough shelter for several people. Being installed at 2 meters off the ground it would only be a danger for the tallest of pedestrians.

    While there are no plans to take Lampbrella into production, Belyaev says he recently introduced his creation to one Moscow Department and insists this creation should be installed on the street where a lot of people walk but there are no canopies to provide shelter.