Thomas Edison tried two thousand different
materials in search of a filament for the light bulb. When none worked
satisfactorily, his assistant complained, "All our work is in vain. We
have learned nothing."
Edison replied very confidently, "Oh,
we have come a long way and we have learned a lot. We now know that there are
two thousand elements which we cannot use to make a good light bulb."
No comments:
Post a Comment