CORDELIA MOLLOY / SCIENCE PHOTO LIBRARY CORDELIA MOLLOY / SCIENCE PHOTO LIBRARY
Magnetic fields. Bar magnets with iron filings aligned around them. The magnetic field induces magnetism in each of the filings, which then line up in the field. Although the field is actually continuous, interactions between the filings cause them to accumulate in thin arcing lines. The two ends of the magnets are opposite poles that have an attractive force, which is visualized by the filings that lie between them.
Model release not required. Property release not required.