When you go running in the woods in your running tights, elastane is the reason they fit you so comfortably. Elastane is an elastic material that allows the fabric to stretch and adapt to your body.

But when elastane fibres are mixed with cotton, wool or other fibres, it will be extremely difficult to separate out the different fibres, and therefore the materials in the clothes cannot be recycled. For this reason, clothes and other textiles are among the materials that we are the worst at recycling.

But this may change, says Assistant Professor Steffan Kvist Kristensen from Aarhus University. Together with a number of colleagues, he is behind a new technology that can separate out fibres in mixed fabrics.

“We’ve developed a method to remove elastane completely from nylon. We’re not quite there yet with cotton, because some of the fibres are broken down in the process. But we believe, with some adjustments, we can solve the problem,” he says, “The fibres only break apart if we break the chains of molecules” .

The many links in the elastane chain are bound together by a small molecule called adiamine. By heating the clothes to 225 degrees Celsius and adding a specific alcohol, we have found a method to break down the bonds in elastane. When this happens, the chains fall apart and the materials separate. The whole process takes place in what is in effect a large pressure cooker that we feed the textiles into. We then add a little alcohol and some base and heat it up. Then we let it cook for just over four hours, and when we open the lid again, the different fibres will have been separated.

So far, Kristensen and his colleagues have only experimented with two nylon stockings at a time. The technology is therefore not yet ready for implementation at industrial scale. This will require being able to decompose much larger amounts of clothing. “We can only scale things up a little because of the limitations in our equipment. So it’s up to the industry to embrace the technology and scale it up in earnest,” he says, “If they don’t, the technology will never take off.”

Plants do not listen to the radio. But a team of researchers in Greece recently found a way to turn lemons into very small “radio stations” that can broadcast information about their trees’ moisture content to a smartphone—the first step toward creating what the researchers call an “Internet of plants.”

Scientists had previously attached sensors to trees to measure their water use, but “no other team had created a wireless radio network among plants, sending information while consuming only a few microwatts and costing just a few dollars,” says project leader Aggelos Bletsas, a professor of electrical and computer engineering at the Technical University of Crete.

The network consists of several basic components: an existing FM radio station, an antenna (天线) attached to a lemon growing on a tree, a humidity (湿度) sensor in the lemon, a transistor connected to an antenna and an FM receiver. First, the antenna picks up the signal from the FM station, and then passes the signal to the transistor, which is modulated by the humidity sensor. The sensor switches the transistor on and off at a rate dependent on the plant’s moisture level: if the soil is wet or if the atmosphere is humid, that rate is lower; if it is dry, the rate is higher. Finally, the antenna broadcasts this information to the radio receiver on a mobile phone.

In this way, plants can tell farmers if they are thirsty. “We can literally ‘listen’ to the moisture of the plant, using our mobile FM radio with a $3.4 sensor,” Bletsas says. “Two of these sensors for every acre on any given farm might change the way we conduct agriculture and ‘understand’ plants.” He notes that more sensors may be needed for the best possible results. Such real-time information could enable better control of air and soil moisture.

Why go through all this trouble and not just use already common wireless technology, such as Bluetooth? “Not only is our technique less complex, as we are just borrowing signals in the environment,” Bletsas says, but “a Bluetooth-based sensor costs about $25. Our final aim is to launch sensors onto the market costing less than $1.”

“Bletsas and his team are completely changing the way of environmental sensing using very simple equipment and surprisingly little power,” says Alexandros Dimakis, an associate professor of electrical and computer engineering at the University of Texas at Austin, who was not involved in the research. “Their work could be a transformational Internet of Things technology for agriculture and for monitoring the environment.”

Bletsas and his colleagues have already applied for a patent for their innovative technology in America.

California start-up OpenAI has released a chatbot (chat robot) able to answer a variety of questions, but its impressive performance has reopened the debate on the risks linked to AI technologies.

Posted on Twitter by fascinated users, the conversations with the chatbot called ChatGPT show a kind of omniscient (无所不知的) machine, from explaining scientific concepts to writing scenes for a play, university essays or even functional lines of computer code.

“Its answer to the question ‘what to do if someone has a heart attack’ was incredibly clear and relevant,” Claude de Loupy, an expert in automatic text generation told AFP. “When you start asking very specific questions, ChatGPT’s response can be off the mark, but its overall performance remains ‘really impressive’ with a ‘high level’.” he said.

A few years ago, chatbots had the vocabulary of a dictionary and the memory of a goldfish. Now Chatbots are getting much better at the “history problem” where they act in a manner consistent with the history of responses. The chatbots have graduated from goldfish status.

However, like other programs relying on deep learning, ChatGPT has one major weakness: it doesn’t have access to meaning. The software cannot justify its choices, such as explaining why it picked the words that make up its responses.

AI technologies able to communicate are increasingly worrying some observers. They voice concern that these technologies could be misused to trick people. What does ChatGPT think of the risk? “There are potential dangers in building highly complex chatbots, particularly if they are designed to be indistinguishable from humans in their language and behavior.” the chatbot said.

Open AI CEO Sam Altman shared his ideas on the debates surrounding AI. “Interesting watching people start to debate whether powerful AI systems should behave in the way users want or their creators intend,” he wrote, “The question of whose values we adjust these systems to will be one of the most important debates society ever has.”