Can a small group of drones（无人机）guarantee the safety and reliability of railways and, at the same time, help railway operators save billions of euros each year? That is the very likely future of applying today's "eyes in the sky" technology to making sure that the millions of kilometres of rail tracks and infrastructure（基础设施）worldwide are safe for trains on a 24/7 basis.

Drones are already being used to examine high-tension electrical lines. They could do precisely the same thing to inspect railway lines and other vital aspects of rail infrastructure such as the correct position of railway tracks and switching points. The more regularly they can be inspected, the more railway safety, reliability and on-time performance will be improved. Costs would be cut and operations would be more efficient（高效）across the board.

That includes huge savings in maintenance costs and better protection of railway personnel safety. It is calculated that European railways alone spend approximately 20 billion euros a year on maintenance, including sending maintenance staff, often at night, to inspect and repair the rail infrastructure. That can be dangerous work that could be avoided with drones assisting the crews' efforts.

By using the latest technologies, drones could also start providing higher-value services for railways, detecting faults in the rail or switches, before they can cause any safety problems. To perform these tasks, drones for rail don't need to be flying overhead. Engineers are now working on a new concept: the rail drones of the future. They will be moving on the track ahead of the train, and programmed to run autonomously. Very small drones with advanced sensors and AI and travelling ahead of the train could guide it like a co-pilot. With their ability to see ahead, they could signal any problem, so that fast-moving trains would be able to react in time.

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.

By day, Robert Titterton is a lawyer. In his spare though he goes on stage beside pianist Maria Raspopova — not as a musician but as her page turner. "I'm not a trained musician, but I've learnt to read music so I can help Maria in her performance."

Mr Titterton is chairman of the Omega Ensemble but has been the group's official page turner for the past four years. His job is to sit beside the pianist and turn the pages of the score so the musician doesn't have to break the flow of sound by doing it themselves. He said he became just as nervous as those playing instruments on stage.

"A lot of skills are needed for the job. You have to make sure you don't turn two pages at once and make sure you find the repeats in the music  when you have to go back to the right spot." Mr Titterton explained.

Being a page turner requires plenty of practice. Some pieces of music can go for 40 minutes and require up to 50 page turns, including back turns for repeat passages. Silent onstage communication is key, and each pianist has their own style of "nodding" to indicate a page turn which they need to practise with their page turner.

But like all performances, there are moments when things go wrong. "I was turning the page to get ready for the next page, but the draft wind from the turn caused the spare pages to fall off the stand," Mr Titterton said, "Luckily I was able to catch them and put them back."

Most page turners are piano students or up-and-coming concert pianists, although Ms Raspopova has once asked her husband to  help her out on stage.

"My husband is the worst page turner," she laughed. "He's interested in the music, feeling every note, and I have to say: 'Turn, turn!' "Robert is the best page turner I've had in my entire life."