In the field of chemistry, one often sees that a very small quantity of a particular substance can completely transform a tremendous amount of surrounding matter. Its action is that of a catalyst, effecting change without itself being altered in any way.
According to the laws of science, it can be inferred that even the application of minimal effort can sometimes allow a person to have a profound impact on forces which appear to be more powerful.
One can ask: "How can we, the Chosen People, who are small in number, be expected to successfully carry out our mission to build a 'dwelling-place for G-d down below' by 'perfecting the entire world for His Kingship?'"
Since G-d does not give us any commandments that we cannot fulfill, we can proceed with the confidence that it is indeed possible for the few to affect the many, in accordance with this scientific principle.
Igros Kodesh of the Rebbe, Vol. 20, p. 259