Status Updates From Mathematician's Delight (Do...

‘[…] For a locomotive engineer one hundredth of a second is a short time; for the radio engineer, who thinks in terms of so many millions cycles a second, a hundredth of a second is an eternity. The pure mathematician, whose results may be used by any of these men, can be sure of satisfying every possible demand only by giving the exact result.’

‘There are other reasons for using the exact speed. For one thing, practical men are not agreed on the shortest amount that need be considered. The carpenter works in hundredths of inches, the engineer in thousandths, the scientist in millionths—microbes, atoms, rays of light. […]

The second derivative measures ‘the force acting on a moving body.’ That is why it is important in understanding the momentum of loss-functions!