The IBM 704 had an early display capability in about 1958. About that time Livermore became concerned about plasma released above the atmosphere. It did not occur to me that those who studied cosmic rays had already done tedious hand calculations about the trajectory of charged particles in the magnetic dipole field of the earth. I wrote a program for the 704 to calculate this and record the results on film so that it could be viewed stereoscopically. It worked very well—in fact a bug in the program caused points on the curve to be of different intensities and this noise was consistent between the two stereo frames. This helped the eye synchronize between the two images and properly identify points on otherwise smooth parts of the curve.

Later I learned how certain integrals could be derived for these motions thru the use of vector potentials. These could be used to show that each ‘Larmor’ orbit of the particle was tangent to two surfaces which bounded the particle away from the atmosphere except near the poles.