Pierre-Gilles de Gennes

Pierre-Gilles de Gennes (October 24, 1932 – May 18, 2007) was a French physicist and winner of the Nobel Prize in Physics in 1991.

Quotes



 * Benjamin Franklin performed a beautiful experiment using surfactants; on a pond at Clapham Common, he poured a small amount of oleic acid, a natural surfactant which tends to form a dense film at the water-air interface. He measured the volume required to cover all the pond. Knowing the area, he then knew the height of the film, something like three nanometers in our current units. This was to my knowledge the first measurement of the size of molecules. In our days, when we are spoilt with exceedingly complex toys, such as nuclear reactors or synchrotron sources, I particularly like to describe experiments of this Franklin style to my students. Surfactants allow us to protect a water surface, and to generate these beautiful soap bubbles, which are the delight of our children.
 * "Soft Matter" Nobel lecture (9 December 1991) - full text in PDF format


 * A dense film of a conventional surfactant is quite impermeable. On the other hand, a dense film of Janus grains always has some interstices between the grains, and allows for chemical exchange between the two sides; "the skin can breathe". This may possibly be of some practical interest.
 * "Soft Matter" Nobel lecture (9 December 1991)


 * The final lines are not mine: they come from an experiment on soft matter, after Boudin… An English translation might run like this:
 * Have fun on sea and land Unhappy it is to become famous Riches, honors, false glitters of this world All is but soap bubbles
 * No conclusion could be more appropriate today.
 * "Soft Matter" Nobel lecture (9 December 1991)


 * Le vrai point d'honneur [d'un scientifique] n'est pas d'être toujours dans le vrai. Il est d'oser, de proposer des idées neuves, et ensuite de les vérifier.
 * The real point of honor [for a scientist] is not to be always right. It is to dare to propose new ideas, and then to check them.
 * As quoted in La Science des Rêves, Science et Vie Junior, 214, (18 May 2007), p. 13