Now don't get me wrong, Feynman was a fully smart dude, but in this quote I think he missed the mark.If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generation of creatures, what statement would contain the most information in the fewest words? I believe it is the atomic hypothesis that all things are made of atoms - little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling each other when squeezed into one another. In that one sentence, you will see, there is an enormous amount of information included about this world, if just a little imagination and thinking are applied.
Firstly, with the simple alteration of the first part to "All things are made of atoms - little particles of 92 types that move etc..." much more information is packed in with minimal extra words such that it still satisfies his criteria for qualification.
But presuming that the intention is to get the ball rolling again as it were, I think that the great man has missed the mark.
Certainly his sentence contains huge amounts of actual information (though my addition contains more ), but it fails to give the clue as to how you get to it.
Democritus and the atomists of ancient Greece had potentially this knowledge at their fingertips, but for thousands of years science effectively stood still anyway.
No, the sentence that would actually start the thinking process again, to begin the climb back up to scientific and technical advancement, would not pertain to the fundamental particulate nature of material, but would rather have to concern itself with the scientific method.
Something of the nature that "knowledge of the nature and applications of the world can be obtained by investigating and quantifying the effects of two variables on each other, while holding other variables that might also be exerting an effect in an unchanged condition."
It is rather to the person of Galileo that we refer as "the father of science" than Democritus, and for good reason. It is the process that is key here - not the facts established thereby.
Feel free to improve upon my poor attempt at coming up with 'the sentence ' by the way, but you get my point I hope. Sort of like the difference between giving a man a fish and teaching him how to fish.