### The Who?, What?, Where?, When?, and Why? of Physics

Robert Howard Kroepel
Lakeside Studios
New Durham, New Hampshire, USA

People often seek answers to questions of Who?, What?, Where?, When?, and Why?

What are the Who?/What?/Where?/When?/Why? of the science of physics?

Physics has been defined as the science which studies the forces which cause changes of inertial states.

What are forces? What is a force?

A force is a push or a pull. A force is the cause of a change of inertial state.

What are inertial states? What is an inertial state?

An object is either at rest or in motion.

Inertia is the resistance to a change of motion.

An inertial state is a condition of either being at rest or being in motion.

What are changes of inertial states?

A change of inertial state is a change of a condition (1) from being at rest to being in motion--acceleration--or (2) from being in motion to (A) being at rest--deceleration--or (B) being in motion in a different direction--acceleration or deceleration.

We thus observe that a change of inertial state is an acceleration or a deceleration caused by a force--by a push or a pull.

The Who?/What?/Where?/When?/Why? questions in physics can be focused upon the forces which cause changes of inertial states.

The universe consists of three realities: 1. The spatial reality--space; 2. the temporal reality--time, 3. the physical reality--matter and energy, the people, things and events comprised of matter/energy.

NOTE: Infinity is not a number but a condition of having no mathematical or physical limitations.

The spatial reality is intuited by the expression X + i wherein X = a finite volume and i = an infinite volume which surrounds any finite X-volume. Thus, for any volume of X finite radius/diameter, there is a surrounding volume of i infinite/unbounded/unlimited radius/diameter.

By X + i space is intuited to be an infinite volume, a volume of infinite dimensions.

Thus, space is the place wherein time happens and physics exists.

Space deals with Where?

Space is the Where? of physics.

Spatial coordinates therefore provide answers to Where? questions in physics.

The temporal reality is intuited to be the use of time-intervals, durations, originally derived from naturally occurring periodic motions, to measure the occurrences of events in sequences of events.

Time deals with When?

Time is thus the When? of physics.

Timepoints therefore provide answers to the When? question in physics.

Observe that people often describe people/things/events by terms/phrases which describe Where? without necessarily referring to descriptions of When?

People may describe an event that happened/as happening at specified spatial coordinates x, y and z without specifying the temporal coordinate t; x, y and z would give us Where? without the t that would give us When?

People may describe Where? = In her own backyard as where Jane threw a ball to Dick without specifying When? Jane threw the ball to Dick.

The When? can be implied as either known or knowable, but, nevertheless, people can describe people/things/events by Where? spatial coordinates without necessarily having to refer to a When? temporal coordinate.

People may describe an event that happened/as happening at a specified temporal coordinate t, timepoint t, without specifying the spatial coordinates x, y and z which would give us Where?

People may describe When? = Timepoint T as the temporal coordinate t at which Jane threw the ball to Dick without specifying Where? Jane threw the ball to Dick.

The Where? can be implied as either known or knowable, but, nevertheless, people can describe people/things/events by a When? temporal coordinate without necessarily having to refer to the Where? coordinates.

Conversely, people often describe people/things/events by When? without necessarily describing Where?

The physical reality is intuited to be the people/things/events comprised of matter/energy, the matter/energy which comprised people/things/events, who/which, by being comprised of matter/energy, are real in contrast to being the content of ideas.

Matter/energy deals with What?

The physical reality as matter/energy is thus the What? of physics.

Matter/energy is also the cause of, the force which causes, changes of inertial states of people/things, the force which causes changes of inertial states, the force which is both the source and the cause of causality, the sequence by which people/things/events who/which are causes cause/create [by forces] people/things/events who/which are effects.

Causality describes the Why? of physics.

An explanation is therefore the description of the causality wherein people/things/events who/which are causes caused/created people/things/events who/which are effects.

An explanation answers the Why? by describing the people/things/events who/which as causes cause/created the people/things/events who/which are effects.

Physics as matter/energy is the source and cause of causality and therefore is thus the Why? of physics.

Thus the Who/What and Why of physics is the matter/energy--the What--which comprises people--the Who/things/events who/which are causes of effects and are therefore the forces--the Why--which cause changes of inertial states of people/things/events; the Where of physics is space; and the When of physics is time.