Multiplying degrees together is not a meaningful concept.
But you can compose rotations.
Multiplying decibels together is also not meaningful, but you can compose scaling.
But you can compose rotations.
Multiplying decibels together is also not meaningful, but you can compose scaling.
Curious what you think of the d_theta * d_phi term in a spherical coordinates integral...
While rotation is naturally oriented like a bivector (plane), solid angle is naturally oriented like a trivector (3-space).
The natural representation is as a kind of (unitless) ratio formed from 3 vectors, not the product of two vector–vector ratios.