Life may have evolved on at least three planets within a newly discovered solar system 39 light years from Earth. Astronomers at the NASA have discovered no less than seven roughly Earth-sized worlds orbiting a dwarf star in the system. Scientists had previously identified a tiny number of "exoplanets", which are believed to have the qualities needed to support life. However, the new system contains an unprecedented(前所未有) number of Earth-sized, probably rocky planets, and is being acknowledged as an "accelerated leap forward" in the search for extraterrestrial (外星球的)life.

    Three of the new planets are said to be particularly promising because there might exist oceans. Thomas Zurbuchen, associate administrator of NASA, told a press conference in Washington: "This gives us a hint that finding a second Earth is not a matter of 'if', but 'when'."

    The planets were discovered using NASA's Spitzer Space Telescope, which was able to track how fast each of the planets crossed the star Trappist-l and completed an orbit. From this the research team calculated how far the planets were from their star, and therefore how likely they are to be habitable.

    NASA's Hubble Space Telescope is already being used to search for atmospheres around the planets. Future telescopes, including the proposed European Extremely Large Telescope and the James Webb Space Telescope, may be powerful enough to discover markers of life, such as oxygen in the atmospheres of exoplanets.

    Astronomers believe there could be as many as 40 billion potentially habitable worlds in our galaxy, the Milky Way. Prof Zurbuchen said that now was a "gold-rush phase" in the search for these exoplanets.

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    Palaces are known for their beauty and splendor, but they offer little protection against attacks. It is easy to defend a large building, but usually these buildings are not designed with the comfort of a king in mind. When it comes to structures that are both beautiful and defensive, the European castle is a big success.

    Castles were originally built in England by the Normans in 1066. They built towers and walls to secure the land they had taken. These castles provided the Normans with a quiet and safe place. They also served as bases of operation for attacks. In this way castles served both defensive and offensive roles. Besides, castles served as offices for governors. Those that were socially beneath the governor would come to report affairs and express their respect. They would address problems, handle business, feast, and enjoy festivities in castles. So castles served as social centers as well.

    The first castles were made from earth and wood, and they were likely to suffer from attacks by fire. Then wooden castles were gradually replaced by stone, which greatly increased the strength of these towers and walls. However, attackers could throw flaming objects into castles through the windows or burn the wooden doors. This led to moving the windows and entrances off of the ground floor and up to the first floor to make them more difficult to access.

    During the Middle Ages, attacks increased in regularity, so castle defenses were updated. Arrow-slits were added. They were small holes in the castle, which allowed defenders to fire without being hurt. Towers were built from which defenders could provide fire on both sides. The towers were connected to the castle by wooden bridges, so that if one tower fell, the rest of the castle was still easy to defend. A lot of rings of castle walls were constructed, so that even if attackers went past one wall, they would be caught on a killing ground between inner and outer walls. All of these increased the defense of castles.

    The end of castles can be attributed to gunpowder. During the 15th century, artillery, a kind of large guns, became powerful enough to break through stone walls. This greatly made the role of castles less effective. Though castles no longer serve their original purposes, remaining castles receive millions of visitors each year who wish to experience the situations of ancient times.

    Are you a morning person? You might not like the findings in this new research.

    From a lack of air and drinking water to solar radiation, theoretical Mars pioneers face any number of potential obstacles to settling on the red planet. Now, scientists have found something else to add to the list: seriously messed-up biological clocks.

    One day on Mars - which scientists refer to as the solar day, or “sol”- is 37 minutes longer than a day on Earth. A team of European scientists recently demonstrated why that could be a problem.

    Circadian rhythms are the body's natural cycles of rest and waking, which tend to follow roughly 24-hour light-dark cycles. These natural rhythms - which play a role in biological functions including brain wave activity and hormone production - can be interrupted by things like jet lag（时差）and night shift work.

    For the study, the researchers compared mice with healthy, 24-hour circadian clocks to mice with a genetic change that caused them to have shorter, 20-hour circadian clocks. The mice with healthy biological clocks were more likely to survive and reproduce, while the mice with shorter biological clocks were more likely to die off.

    What does this all have to do with space travel? Since the Martian sol is longer than a day on Earth, people with shorter circadian clocks could suffer from health problems as they try to adapt to the rotational speed of the red planet.

    Unfortunately, the body is unlikely to adapt to the new conditions or “learn” to develop a longer clock. As Loudon explained,“ Learning is not a likely option.”

    In other words: Sorry, super-early risers - NASA might not want you for the next Mars mission.

Everyone has a phone in their pocket nowadays, but how often do we really use them for their original purpose-to make a call? Telephone culture is disappearing. What brought us to this moment, and what are its effects?

"No one picks up the phone anymore," wrote Alex C. Madrigal on The Atlantic. The reflex of answering-centu20^th—telephonic culture—is gone."

The shift is of course due in large part to more communication options: Texting with photos, videos, emojis, reaction gifs, links and even voice messages can be a more attractive option.

Texting is light and fun, not nearly as demanding of your attention as a phone call. It can also be done with multiple people at the same time. Social media, email and video calls have also eaten away at traditional phone calls.

In recent years, another reason has caused people to ignore phone calls completely: robocalls. Robocalls are automate messages from organizations verifying your phone number or telemarketers trying to sell something. Americans received 22.8 billion robocalls halfway through 2020, equaling an annual rate of 45.6 billion, slightly below 2018 numbers, according to YouMail, a robocall protection service and blocking app.

As telephone culture disappears, what is the loss of a singular family phone doing to the family unit? Early landline phones unified family members, whereas mobile phones isolate them.

"The shared family phone served as an anchor for home," said Luke Fernandez, a Weber State University computer-science professor and co-author of Bored, Lonely, Angry, Stupid: Feelings About Technology, From the Telegraph to Twitter. "With smartphones we have gained mobility and privacy. But the value of the home has been diminished, as has its ability to guide and monitor family behavior and perhaps connect families more closely," Fernandez said.

Of course, as technology progresses, lives always change for better or for worse. With the loss of telephone culture, families will need to find other ways to unite.

While they are at home alone, many people imagine {#blank#}1{#/blank#} (have) the opportunity {#blank#}2{#/blank#} （sing) together, which {#blank#}3{#/blank#} (realize) by a virtual choir. Anyone can take part in {#blank#}4{#/blank#} from anywhere and does not need a studio. It {#blank#}5{#/blank#} (prove) to be a positive influence on the lives of many people. Award-winning composer and conductor Eric Whitacre came up {#blank#}6{#/blank#} the idea of the virtual choir, {#blank#}7{#/blank#} began studying music in 1988. {#blank#}8{#/blank#} (finish) university in 1995, he received a master's degree in {#blank#}9{#/blank#} (music)composition in 1997. In 2009, his first virtual choir received, {#blank#}10{#/blank#} (million) of views on the Internet. The virtual choir has become a worldwide phenomenon since then. In 2014, he formed the Virtual Youth Choir for UNICEF, and 2, 292 young people from 80 countries sang his song"What If".

Recently, I carried out an investigation to discover what it was that prevented people from journalling. {#blank#}1{#/blank#} So, today, I want to introduce a very simple tool — The MicroMOVEment Wheel. It will help you pick up your journal even at times when you really don't feel like it.

{#blank#}2{#/blank#} She describes creating this method so she could use it as a creative planning tool for her writing projects and goals. While it was originally aimed at writers, you can use this technique to help you complete any project in a fun and creative way.

{#blank#}3{#/blank#} Here's how it works. Take a blank sheet of paper and draw a large circle, and then another smaller circle in the middle, In the center circle, write down what you are inspired to achieve. Remember, journaling does not need to feel like a chore in your day. So come up with descriptions for your journalling that are inspiring and energizing. {#blank#}4{#/blank#} These are what SARK refers to as the MicroMOVEments. Each MicroMOVEment is five minutes in length, So, in the case of journalling, that would represent a minimum of up to five minutes of journalling in one sitting, on any given day.

Let's say you're new to journalling. By setting aside five minutes out of your day, you could write one word in your notebook that sums up a feeling or an experience. {#blank#}5{#/blank#} The idea of the MicroMOVEment is to create easy steps to get your journal writing or writing projects moving. When you keep the steps small, it will become doable and achievable.

A. Next, divide the rest of the circle into eight equal parts.

B. It is the brainchild of international bestselling writer SARK.

C. There are no hard-and-fast rules when it comes to journalling.

D. Where to start and not having enough time were amongst the top responses.

E. Daily tasks such as sweeping and washing are time-consuming and laborious.

F. Then, list any associated words, images or thoughts that are generated by the word.

G. The medicine with this approach is breaking your actions down into the tiniest steps.