Famous quotes containing the words challenge and/or problems:
“Women must try to do things as men have tried. When they fail their failure must be but a challenge to others.”
—Amelia Earhart (1897–1937)
““What we know, is a point to what we do not know.” Open any recent journal of science, and weigh the problems suggested concerning Light, Heat, Electricity, Magnetism, Physiology, Geology, and judge whether the interest of natural science is likely to be soon exhausted.”
—Ralph Waldo Emerson (1803–1882)