Scientists in Switzerland have used lasers (激光) to change the path of a lightning strike (雷击的路径). The experiment suggests that in the future, lasers might be useful for protecting large buildings from lightning.

Lightning can be extremely powerful and cause serious problems on the ground. Lightning strike can cause fires, destroy buildings, and even kill people. The damage from lightning costs billions of dollars every year. In the US, lightning strikes killed close to 450 people between 2006 and 2021.

Scientists have been trying to find a way to protect buildings from lightning for a long time. Now the best Way is by putting metal rods (金属竿) on the buildings. These rods are connected to the ground. The lightning is attracted to the rods, which safely guide the electricity into the ground. But lightning rods can only protect a small area. Some buildings—such as airports are so large that it’s difficult to protect the whole building using lightning rods.

Another idea is to use lasers to guide lightning. Scientists had been working on the idea for over 20 years. They have successfully guided lightning with lasers inside a lab. But until the summer of 2021, scientists could guide lightning with lasers outside. Using a powerful laser, scientists in Switzerland were able to guide lightning tor meters.

The heat from the laser creates a path of air that is less thick than the air around it. The path also has a special charge (电荷). The lightning can follow this path almost as if it were a lightning rod. Scientist Matteo Clerici said, “The fact that we managed to do it in an outdoor environment is a very big step.”

But the laser still didn’t guide the lightning as far as the scientists would like. Besides, the laser is also very expensive. The scientists say it cost about $2 billion. It will probably take 10 or more years before a laser like this is truly able to protect large buildings.

A team of Volkswagen (大众) designers and engineers developed a high-tech office chair that you can drive at a top speed of 12mph (20km/h).

Most high-tech office chairs simply prevent either water or kinds of pollution, or they are designed at a higher standard, especially about ergonomics (人类工程学). But Volkswagen’s recent take on a high-tech office chair shows just how low the standard is at the present.

The German car producer designed an office chair with a built-in motor and controls allowing the user to drive it at a top speed of 12mph. And that’s just one of the crazy ideas that built into this one-of-a-kind piece of office furniture (家具).

The main goal of this project was to put many smart parts that were found in a real Volkswagen car into an office chair, and the team did a truly excellent job.

Not only did they manage to put in a real motor and driving controls, but also a seat belt, honk, built-in speakers, and even tiny parts for the chair wheels.

The futuristic office chair also comes with 360-degree collision prevention sensors (感应器), a backup camera, a touchscreen display, headlights built into the armrests, LED party lights, USB charging, a small pocket for storing documents and the WV logo added into the headrest.

If you’re wondering about self-acting driving, Volkswagen says that its high-tech office chair comes with an exchangeable battery (电池), which offers a list of around 12km on a single charge.

How do we know the time? A clock, a watch or a mobile phone can help us. However, many years ago there were no clocks and knowing the time was not so easy. Over the centuries people have developed different ways of telling the time.

About 5,500 years ago, the Egyptians invented the sun clock. This was a tall stone building. Its shadow(影子)showed the movement of the sun. So people were able to know midday. The Egyptians made a sundial about 3,500 years ago. It was smaller than the sun clock and could measure the time for half a day. On cloudy days or at night it was impossible to tell the time with a sun clock or a sundial. Water clocks were the first clocks not to use the sun. The idea is simple. Water flows from one container to another, When the water reaches a certain level, it moves a lever(控制杆)and this shows the hours. The Egyptians used water clocks about 3,400 years ago. These clocks were popular in the Middle East and China. But they failed to make people know the exact time.

In the 13th century, the mechanical clock was invented. This was more exact, but it was expensive to make one. Over the next few centuries, it was developed. For example, springs(发条)were added around 1,500. This enabled people to get the correct time and allowed clocks to be smaller. In 1936, the first quartz clock was developed. Clocks became cheaper to build. It’s easy for ordinary people to own a clock. People began depending on them more and more to ran business, markets and so on. More recently, in 1956, came the digital clock. And nowadays satellites send our mobile phones the time to the exact second.

There has been a lot of progress in timekeeping. Clocks are always changing but some things never change. Many of us still have trouble getting out of bed on time and not missing appointments.

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