Well technically you can neglect anything you want.

Man, physics is stupid difficult to learn without spherical cows and frictionless surfaces.

Hell, astrophysics has so much “eh we can ignore this number because it’s so tiny compared to a black hole.”

And don’t forget about Quantum. There’s a whole time-dependent AND time-independent wave equation.

To be fair, a spherical cow is worth its weight in money

He was a helicopter gunner / pilot… Air resistance really matters!!