Dipole model of the Earth's magnetic field (MLAT), or geomagnetic latitude, formula_10 is measured northwards from the equator (analogous to geographic latitude) and is related to formula_9 by formula_12. In this case, the radial and azimuthal components of the magnetic field (the latter still in the formula_9 direction, measured from the axis of the north pole) are given by formula_14 formula_15 formula_16 where formula_17 in this case has units of Earth radii (formula_18). Invariant latitude is a parameter that describes where a particular magnetic field line touches the surface of the Earth. It is given by formula_19 or formula_20 where formula_21 is the invariant latitude and formula_22
What on Earth! Pindal in December 1963, with the working title "Automation", with the intention of showing how "in spite of appearances, man is the master in the automated world." The working title would become "Martians", before the final title "What on Earth!" was chosen. Drew was brought in to work on the film in 1965 and 1966, with Brittain assigned to write narration. Pindal's original idea of "man as the master" is not reflected in the final version of the film, and NFB archivist and blogger Albert Ohayon believes Brittain may have been responsible for this key change. "What on Earth!" was