Surface Friction

Famous quotes containing the words surface and/or friction:

    The surface of the earth is soft and impressible by the feet of men; and so with the paths which the mind travels. How worn and dusty, then, must be the highways of the world, how deep the ruts of tradition and conformity!
    Henry David Thoreau (1817–1862)

    We have got onto slippery ice where there is no friction and so in a certain sense the conditions are ideal, but also, just because of that, we are unable to walk. We want to walk so we need friction. Back to the rough ground!
    Ludwig Wittgenstein (1889–1951)