【推荐1】The artificial control of the weather, known as weather modification, seems like something out of a science fiction novel, but now it seems to have become a reality. Weather Modification International, a North Dakota-based company, is using planes to target clouds and draw out more rain from them.

The concept behind the practice, which is called cloud seeding, has been around for decades. But there is new urgency due to climate change and a rapidly growing global population, which have disrupted (中断) global water supplies.

Weather Modification describes cloud seeding as "an improvement"of the natural raining process. The technology makes storms more efficient by getting additional moisture (水汽) out of clouds.

"If there are no clouds in the sky that have any moisture in them, then we can't do anything."said Brian Kindrat, an aircraft captain at Weather Modification. "What we can do is tap into what is there and assist mother nature."

To do this, pilots target clouds with lots of moisture and put small amounts of a silver iodide (碘化银) mixture. The water in the clouds condenses (凝结) and becomes heavy. Then, it falls to the ground as rain.

The company sees cloud seeding as part of a solution for droughts (干旱). "We aren't going to solve large climate shifts in areas, but if you went back and you looked in California and said if we had an additional 10%, 15%, 20% of snowpack and rain over the last 10 year...it would be significantly different." said Neil Brackin, president of Weather Modification. "With such a program as cloud seeding, additional water for cities and agriculture is available. In fact everybody can benefit from it." Brackin added.

But there are concerns about cloud seeding's long-term impacts. For example, it's unclear how making it rain in one state affects a neighboring state. It's also up for debate who "owns" the water―such as which state or country―that comes out of the clouds. There are also environmental questions, such as ones related to the long-term impacts of silver iodide.

Although some critics may have concerns about companies impacting the weather, the company denies that it's "playing God". "We're not really playing God. I think that's really overstating what we're doing."Brackin said. "We're being very specific and environmentally friendly in what we're doing to enhance the natural raining."

【推荐2】Robots are increasingly being developed to think and act like humans. But one common human quality that has been difficult for engineers to recreate in machines is humor.

Most robots are powered by artificial intelligence, or AI. Some have performed better than humans in tests designed to measure machine intelligence.

Computer scientists have also hoped to give robots technical skills to help them recognize, process and react to humor. But these attempts have mostly failed.

Kiki Hempelmann is a computational language expert who studies humor at Texas A&M University. “Artificial intelligence will never get jokes like humans do,” he told the Associated Press. The main problem, Hempelmann says, is that robots completely miss the context of humor.

Tristan Miller is a computer scientist and linguist at Darmstadt University of Technology in Germany. In one research project, he studied more than 10,000 puns(双关语).

Puns are a kind of joke that uses a word with two meanings. For example, you could say, “Balloons do not like pop music.” The word “pop” can be a way of saying popular music; or, “pop” can be the sound a balloon makes when it explodes.

But a robot might not get the joke. Tristan Miller says that is because humor is a kind of creative language that is extremely difficult for computer intelligence to understand.

Despite the difficulties, Darmstadt University’s Miller says there are good reasons to keep trying to teach humor to robots. It could make machines more relatable, especially if they can learn to understand sarcasm(讽刺), he noted. Humans use sarcasm to say one thing but mean another.

But Texas A&M’s Kiki Hempelmann is not sure such attempts are a good idea. “Teaching AI systems humor is dangerous because they may find it where it isn’t, and they may use it where it’s inappropriate,” he said. “Maybe bad AI will start killing people because it thinks it is funny,” he added.

【推荐3】Sugar cane（甘蔗）contains around 10% sugar. But that means it contains around 90% non-sugar—the material known as bagasse （甘蔗渣）which remains once the sugar-bearing juice is squeezed out. World production of cane sugar was 185 million tonnes in 2017 , which results in a lot of bagasse.

At the moment, most of it is burned. But Zhu Hongli, a mechanical engineer at Northeastern University, in Boston, thinks it can be put into better use. As she, and her colleagues describe, in Matter this week, with a bit of improving bagasse makes an excellent and biodegradable （可生 物降解的）replacement for the plastic used for disposable food containers such as coffee cups.

Dr. Zhu is not the first person to have this idea. But previous attempts tended not to survive contact with liquids. She knew from previous research that the main reason why past efforts fell to pieces when wet is that bagasse is composed of short fibres which are unable to hold the finished product. She therefore sought' to insert a suitably long-fibred substance.       

Bamboo seemed to be the best choice. It grows quickly /degrades readily and has appropriately long fibres. And it worked. When the researchers blended bamboo remaining into bagasse, they found that the result had a   strong crossing of short and long fibres.

To put their new material through its paces, Dr. Zhu and her colleagues first poured hot oil onto it and found that, rather than passing through the material, as it would have with previous, bagasse products, the oil was resisted by their invention.

They also found that when they made a cup out of the stuff and filled it with water heated almost to boiling point, the cup remained unbroken for more than two hours. Though this is not as long as a plastic cup would   Hast, it-is long enough for all practical purposes.