Scientists have already applied robots like Roomba to work in the agriculture (农业). A Roomba works because it has wheels that function well on flat ground. However, fields are full of rough and rocky environments, which means it is difficult for robots to work in the fields. Luckily, scientists thought of centipedes (蜈蚣). With tens to hundreds of legs, they can move on any places without stopping. If they stop moving their body parts and feet, they basically stop moving instantly.

A team led by Chong developed a theory that proposes that adding leg pairs to the robot increases its ability to move firmly over challenging environments.

To test this, Juntao conducted a series of experiments where he and Daniel Soto built models to simulate (模拟) different natural environments. He then tested the robot by increasing its number of legs by two each time, starting with six and finally increasing to 16. As the leg count increased, the robot could more easily move across the surfaces, even without sensors. Finally, they tested the robot outdoors on real environments, where it was able to move in a variety of environments.

The researchers are applying their discoveries to farming. Goldman has co-founded a company that wants to use these robots to weed (除草) farmland where weedkillers are ineffective. “It’s truly impressive to see the multilegged robot easily moves on both lab-based and outdoor environments,” Juntao said. “Now we are deciding the most suitable number of legs to achieve motion. In the future, we hope to apply them for space exploration, and even search and rescue.”

Solar power is one of the fastest growing sources of renewable power globally these years. Solar photothermal (光热) and solar photovoltaic (PV光伏)are both technical forms.

The thermal power station adopts the generation mode of “light--heat--electricity”. Thousands of heliostats (定日镜) reflect the sunlight to the surface of the heat absorber on the top of the solar tower. The concentrated sunlight is then used either directly as a source of heat, as in solar water heating, or to drive a heat cycle such as a Sterling Engine. PVs use semi-conductor technology to directly convert sunlight into electricity. The PV line is connected to the direct current (DC) distribution cabinet in parallel through the DC combiner box. After confluence (汇合), it is connected to the DC input end of the inverter to convert DC into alternating current (AC). The AC output end of the inverter is connected to the AC distribution cabinet and directly connected to the user side through the AC distribution cabinet.

Additionally, since solar thermal directly produces heat, it can store thermal energy into various media. Therefore, solar thermal can potentially generate power 24 hours a day. On the other hand, PVs only operate when the sun is shining, and must be coupled either with other power generation mechanisms to ensure a constant supply of electricity.

The scale of PV power generation can be large or small, ranging from thousands of watts to hundreds of megawatts, but photothermal power generation is typical economies of scale. With the increase of scale, the lower the power generation cost.

PV power generation is less limited by region, for the sun shines on the earth. Compared with other sources of renewable power, the PV system is safe and reliable as well as eco-friendly. Since it can be convenient for local power generation and power supply, you do not worry about consuming fuel or erecting transmission lines. A small PV power can be constructed in a short period with no noise or low pollution.

Babbage, born in London in 1791, was a great mathematical genius. He was a natural inventor.

When he finished school, he went to study mathematics at Cambridge University. Later, he got a job teaching at the university. While working there, he designed his “first difference engine”. This was, basically, a hand-operated mechanical calculator.

He took nine years to build a part of the machine. This machine can make complex mathematical calculations. It’s a basic mechanical computer.

Babbage dreamed, however, of more complicated machines. In fact, he didn’t only dream; he began to design them. The result was a series of “analytical engines” which were in fact powerful computers!

His designs contained processors, control units, a memory, and an input/output system. These are the four essential parts of a modern mathematical computer!

Alas! His “second difference engine” couldn’t use electricity since this hadn’t yet become a usable source of power, so Babbage had to make do with mechanical systems. For this reason, the machine was big, complicated and expensive. Though Babbage produced complete plans for the machine, he couldn’t build it. It was too advanced for its age!

It was not until almost 160 years later that Babbage’s “second difference engine” was finally manufactured. The first working version of this machine was built by the Science Museum in London, for the Babbage bicentenary in 1991. A second machine was then built for an American high-tech millionaire, who put it in the Computer History Museum, in California.

Babbage’s analytical engines would have used “programs” like those used in the textile(纺织)industry to make complicated patterns, but they were never built. This brilliant mathematician really was too far ahead of his time!