Beyond the spherical cow | Scilight | AIP Publishing

Avery Thompson; Beyond the spherical cow. Scilight 27 March 2026; 2026 (13): 131110. https://doi.org/10.1063/10.0043345 Download citation file: One of the most well-known approximations in physics is the spherical cow. For generations, physicists have treated cows as spheres, a simplifying assumption to make the math easier. However, this approximation renders several problems unsolvable. Benjamin Lehmann improved upon the utility of this classic approximation by treating the spherical cow as simply the first term of a multipole expansion. This allowed him to resolve higher order effects that were previously impossible to explore. “If you just take the leading order term for the cow’s shape, you lose out on all the effects that completely vanish at the monopole order,” said Lehmann. “The first thing that my mind went to is gravitational waves, because gravitational waves famously only come from the quadrupole and higher moments.” Using his multipole expansion, Lehmann calculated the ra

Avery Thompson; Beyond the spherical cow. Scilight 27 March 2026; 2026 (13): 131110. https://doi.org/10.1063/10.0043345 Download citation file: One of the most well-known approximations in physics is the spherical cow. For generations, physicists have treated cows as spheres, a simplifying assumption to make the math easier. However, this approximation renders several problems unsolvable. Benjamin Lehmann improved upon the utility of this classic approximation by treating the spherical cow as simply the first term of a multipole expansion. This allowed him to resolve higher order effects that