A lecture in 1959 by physicist Richard P. Feynman suggest how it would be possible to directly manipulate atoms for a variety of purposes. Today's scientists and engineers use nanotechnology to make materials with different properties, such as greater strength and lighter weight. They have already created surface materials that fight off dirt and scratches. Some fabrics have sunscreen built into them, which helps protect the wearer from the rays of the sun. Nanotubes that are fifty times stronger than steel have already been created.