If distance is assumed to be change in object's position as measured by its velocity and the length of time observed in the course of that change, then time can be viewed as change of an object's position related to its velocity.

T=D/V

Describing velocity in terms of an object's kinetic energy, V=√(2E

_{k}/M), yields:

T=D/√(2E

_{k}/M)

If you consider distance to be the length measured between an originating point and an ending point (an absolute, ie. nonnegative), and that velocity expressed in terms of kinetic energy will never be negative (notice the square root), there is no way to have negative time.

So, I don't see why we can't just say that the arrow of time is the irreversible change in the spatial orientation of the universe's mass and energy?

I ask in response to reading this: https://www.wired.com/2016/09/arrow-o

If anything is a construct, I'd say it's math and its simplest concepts of addition and subtraction. What is math but a way to relate change, centered on equation?

One apple plus one apple is two apples, we say. But there were always two apples, isolated — by perspective — from the inconceivably vast amount of finite matter and energy as it is decohered before us.

And, in fact (proverbial bong hit here), we are those apples.