According to the Solar Energy Industry Association, the number of solar panels installed(安装)has grown rapidly in the past decade, and it has to grow even faster to meet climate goals. But all of that growth will take up a lot of space, and though more and more people accept the concept of solar energy, few like large solar panels to be installed near them.

Solar developers want to put up panels as quickly and cheaply as possible, so they haven't given much thought to what they put under them. Often, they'll end up filling the area with small stones and using chemicals to control weeds. The result is that many communities, especially in farming regions, see solar farms as destroyers of the soil.

"Solar projects need to be good neighbors," says Jordan Macknick, the head of the Innovative Site Preparation and Impact Reductions on the Environment(InSPIRE)project. "They need to be protectors of the land and contribute to the agricultural economy." InSPIRE is investigating practical approaches to "low-impact" solar development, which focuses on establishing and operating solar farms in a way that is kinder to the land. One of the easiest low-impact solar strategies is providing habitat for pollinators(传粉昆虫).

Habitat loss, pesticide use, and climate change have caused dramatic declines in pollinator populations over the past couple of decades, which has damaged the U.S. agricultural economy. Over 28 states have passed laws related to pollinator habitat protection and pesticide use. Conservation organizations put out pollinator-friendliness guidelines for home gardens, businesses, schools, cities—and now there are guidelines for solar farms.

Over the past few years, many solar farm developers have transformed the space under their solar panels into a shelter for various kinds of pollinators, resulting in soil improvement and carbon reduction. "These pollinator-friendly solar farms can have a valuable impact on everything that's going on in the landscape," says Macknick.

A machine can now not only beat you at chess, it can also outperform you in debate. Last week, in a public debate in San Francisco, a software program called Project Debater beat its human opponents, including Noa Ovadia, Israel's former national debating champion.

Brilliant though it is, Project Debater has some weaknesses. It takes sentences from its library of documents and prebuilt arguments and strings them together. This can lead to the kinds of errors no human would make. Such wrinkles will no doubt be ironed out, yet they also point to a fundamental problem. As Kristian Hammond, professor of electrical engineering and computer science at Northwestern University, put it: "There's never a stage at which the system knows what it's talking about."

What Hammond is referring to is the question of meaning, and meaning is central to what distinguishes the least intelligent of humans from the most intelligent of machines. A computer works with symbols. Its program specifies a set of rules to transform one string of symbols into another. But it does not specify what those symbols mean. Indeed, to a computer, meaning is irrelevant. Humans, in thinking, talking, reading and writing, also work with symbols. But for humans, meaning is everything. When we communicate, we communicate meaning. What matters is not just the outside of a string of symbols, but the inside too, not just how they are arranged but what they mean.

Meaning emerges through a process of social interaction, not of computation, interaction that shapes the content of the symbols in our heads. The rules that assign meaning lie not just inside our heads, but also outside, in society, in social memory, social conventions and social relations. It is this that distinguishes humans from machines. And that's why, however astonishing Project Debater may seem, the tradition that began with Socrates and Confucius will not end with artificial intelligence.

We live in a town with three beaches. There are two parks less than 10 minutes' walk from home where neighbourhood children gather to play. However, what my children want to do after school is pick up a screen — any screen — and stare at it for hours. They are not alone. Today's children spend an average of four and a half hours a day looking at screens, split between watching television and using the Internet.

In the past few years, an increasing number of people and organisations have begun coming up with plans to counter this trend. A couple of years ago, film-maker David Bond realised that his children, then aged five and three, were attached to screens to the point where he was able to say "chocolate" into his three-year-old son's ear without getting a response. He realised that something needed to change, and, being a London media type, appointed himself "marketing director for Nature". He documented his journey as he set about treating nature as a brand to be marketed to young people. The result was Project Wild Thing, a film which charts the birth of the Wild Network a group of organisations with the common goal of getting children out into nature.

"Just five more minutes outdoors can make a difference," David Bond says. "There is a lot of really interesting evidence which seems to be suggesting that if children are inspired up to the age of seven, then being outdoors will be a habit for life." His own children have got into the habit of playing outside now: "We just send them out into the garden and tell them not to come back in for a while."

Summer is upon us. There is an amazing world out there, and it needs our children as much as they need it. Let us get them out and let them play.