But scientific advance sometimes takes place on a much smaller scale than that, and is produced not by scientific genius but by accident. A lot of the breakthroughs that have benefited people most are never going to win a Nobel prize - indeed, some of the best advances were designed for something else entirely. When overhead telephone lines were invented, it was little dreamt that they would make a wonderful gathering place for birds. When the first railway lines were built, it was little dreamt that they would be turned by the Tories into a nationwide network of overgrown paths.
Today I am going to single out a few of the greatest advances made this century, none of which was dreamt of by its inventor.
1. Car wing mirrors These were originally designed so that the driver could see behind him on either side, and can still so be used, but their vital purpose turns out to be to stop cars driving too close to each other. If you passed another car too close in the old days, you would have hit him. Nowadays you just hit his wing mirror with your wing mirror, both swing back and then return to their positions and no harm is done. Bicyclists have joined this trend recently, sprouting wide wing mirrors to keep cars away, though sometimes sporting long flagpoles pointing sideways, which seem to have the same effect.
2. Stationary computers The single greatest advance of the computer or word processor over the manual typewriter is not that it is faster or electronic, but that it has no outside moving parts. The great snag of a typewriter was that the carriage moved right across in every sentence and created the best possible way of knocking over a cup of coffee. Even if you put your cup of coffee in a place where the carriage couldn't possibly reach it, the typewriter would gradually move round on the desk by vibration and hunt the coffee so stealthily that you would not notice it happening. A word processor cannot do this.
3. The cotton bud The cotton bud is the toothpick of the modern era. It can do everything a toothpick can do but is gentle where a toothpick is harsh. A cotton bud can clean inside tape recorders, wipe away wet glue, remove dust, pick up things, dry things, wet things, remove mascara - well, I don't have to go through the list. We all have our favourite uses.
4. The hexagonal pencil and pen
In the old days, when a pencil or pen could no longer write, we would throw it away. Now we can keep it for winding cassettes. Yes, the only thing that fits neatly inside the hole of a cassette and provides the leverage to tighten the tape in a cassette, or spool it on manually, or even break the tape if necessary, is a pencil or Bic ballpoint. Whoever thought of making pencils the right size for this job (or perhaps of making cassettes the right size for pencils) was a genius.
5. Plastic credit cards
How we ever scraped frost off car windows before we had credit cards I cannot imagine. Also pick Yale locks, etc etc.
6. Dental floss
The initial idea of dental floss was to clean between your teeth, but the survival guides say it is incredibly useful for all sorts of other things such as acting as standby string, emergency thread for sewing, etc. (Why did nobody ever come forward with the idea that sewing thread, which is stronger, would make an ideal dental floss?)
7. Yoghurt pots
The arrival of the small plastic yoghurt pot revolutionised indoor gardening, as it meant that at last secretaries in offices had something to hand to plant small flowers in. (There were plenty of small flower pots around before that, but they were not to hand in offices.)
Who would ever have imagined that Italy's favourite food would have become Britain's favourite kindergarten art tool? All those different colours and shapes - butterflies, pipes, wheels, tubes - are rather wasted on Italian dishes. It was almost as if they were waiting to come into their own by being stuck on big white bits of paper by little children in little British schools as components of their first ever art work. And the wonder of it is that if a kindergarten is ever stranded by floods for a few days, the art class can always cook and eat its own drawings.