The world seemed a simpler place. Science would offer an answer to every conceivable problem; there would be nothing that would be beyond the wit and the skill of determined scientists. Watching Tomorrow’s World on BBC television with Raymond Baxter on a Thursday evening was a weekly reassurance of the power of human imagination to inspire innovation, inventiveness and technological breakthroughs.

Perhaps there was a teenage naïveté in having confidence that there was a technocracy capable of resolving every problem that arose, believing that there were white-coated scientists working in university laboratories for whom no question was too difficult. Perhaps it was a reflection of the times; if it was possible to send astronauts to the Moon, then answers to more down to Earth questions should not be a problem. In schooldays, the two questions some believed could be answered were those of perpetual motion and cheap and safe and renewable energy.

The 1973 oil crisis and the massive hike in the price of petrol that followed was a news story of which even schoolboys were aware. Petrol rationing books were sent out to all vehicle owners: my father had two books, one for the Austin Cambridge car he drove, a car that weighed more than a ton and which covered barely more than twenty miles for each gallon of petrol it used and one for his Honda 50 motor bike that had been bought to economise on travel costs. The Honda 50 seemed able to travel huge distances on just a whiff of petrol.

High fuel prices and petrol ration books would not be part of a future imagined in a schoolboy’s mind. Friends who read science fiction books would talk about the possibility of perpetual motion machines, perfectly efficient mechanisms in which no energy was lost. If perpetual motion was possible, then once a machine was built, it would run forever at no cost. Even to a schoolboy, the idea seemed one that seemed something that might work in stories from outer space, but on a planet where gravity and friction couldn’t be avoided, it seemed an unlikely possibility.

Safe and renewable energy in our conversations was going to come from nuclear fusion. One boy suggested that it would be possible to have fusion car engines in which hydrogen and oxygen particles combined to produce heat and that the only exhaust would be water. Fusion research began in the 1940s, seven decades later, there has been no viable technology produced.

As silly as our conversations might have been, there was a confidence about the future.