Science strode ahead in the 19th century, and scientists became much more numerous and more specialised. The establishment of new universities in the second half of the 19th century created academic posts for professional scientists.

Many important discoveries are too complex to be familiar to the general public. However, some are relatively simple to understand.

For example, Louis Agassiz (1807-73) revolutionised geological theory by suggesting that Eurasia had once been covered in ice.

Albert Heim (1849-1937), professor of geology at the Federal Institute of Technology in Zurich, provided the explanation of the formation of the Swiss mountains which is still generally accepted.

The astronomer Rudolf Wolf (1816-1893) devised a formula for counting sunspots, which enabled them to be compared over time. The Wolf sunspot number is still used today.