This week's Horizon starts with technology and ends with science. The making of the Hubble telescope required astonishing degrees of accuracy.
The mirror had to be ground, tested and re-polished, over and over, in a process that lasted a whole year. In the end, embarrassingly, it turned out to have a minute flaw which threatened the entire project. Then an ingenious device was invented to correct the error and, after four years, a space mission went up to install it, in the course of several hazardous space walks. Eventually the telescope was ready to go.
This is where the science begins. The reason for Hubble was to put a telescope where it was not affected by the earth's atmosphere. Now operational, Hubble can look far deeper into space than any previous optical telescope, allowing us to see the birth of galaxies at the very start of time, and to estimate the age of the universe itself far more accurately than before.
All this is explained with clear graphics and astonishing photographs, including those provided by Hubble itself. Most of all, though, we hear from the people involved in making the telescope, putting it in orbit, repairing it and interpreting its findings about the sheer excitement of both pure science and applied technologies. This is a film with true inspiration for would-be scientists as well as information.
Horizon. BBC2. February 10, 9.30-10.30pm
You cannot understand China's present without some reference to its recent past, so this new five-part unit for the geography series Place and People includes archive film about collectivisation and the Great Leap Forward in its survey of Chinese life.
In the main, however, it looks at contemporary China, against the background of the country's varied landscapes: farmland, cities, a hydroelectric scheme, forestry and the great rivers. Designed for ages 14 to 17, the five well-made films focus on the experience of ordinary people in different regions: a farming family in the dry north and another in the lush south; factory workers, builders and a bank employee in Shanghai. and they have some general lessons about winners and losers in the race for economic development.
Place and People: Changing China. Channel 4. Mondays until February 14. 10.30-10.50am. BEST OF THE REST. Kirsty Wark is currently presenting a new series for 14 to 16-year-olds, A Nation Once Again, looking at Scottish devolution. On February 10, however, she travels south to Catalonia, the Spanish region that achieved autonomy in 1979, to see how devolution has worked there, its effect on the sense of Catalan identity and, perhaps most important of all, how it is being financed - a small homage from Scotland to Catalonia.
A Nation Once Again. Channel 4. Thursdays to February 17. 9.30-9.50am.