# Definition of time & its connection with movement of material. In physics we deal with material & without material time cannot be imagined [duplicate]

We get different definition of time? the indefinite continued progress of existence and events in the past, present, and future regarded as a whole. Time in physics is defined by its measurement: time is what a clock reads. In classical, non-relativistic physics it is a scalar quantity and, like length, mass, and charge, is usually described as a fundamental quantity.

But in physics can we have a deep answer?

## marked as duplicate by Chris♦, By Symmetry, StephenG, John Rennie, Qmechanic♦Jan 29 '18 at 13:38

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## 1 Answer

Time is a human construct that only exists in the virtual world of mathematics. It's like someone trying to prove there is a relationship between the circumference of a circle and the diameter. There is no relationship it's an approximation. What was 1 second before atomic clocks? A made up number that continues to evolve. Now it's some arbitrary value of atomic decay. Unlike the charge of an electron that remains constant throughout the universe.

• I think your reasoning would apply to the units used to measure time rather than time itself. One can say time is what is in between events. Obviously it remains immaterial but not forcedly a construction. – Alchimista Jan 29 '18 at 12:59
• I voted this down because time clearly has a significant reality in physics (not to say people waiting for buses and pizza) and as such it makes no sense to say "it only exists in the virtual world of mathematics". – StephenG Jan 29 '18 at 13:44
• @StephenG. No one said time wasn't significant. But you have to admit it is a construct of human creation. Does a fixed quantity of time exist in nature the answer is no. – PeterS Jan 29 '18 at 19:40
• "Time" is a human label. So are e.g. "force" and "length". They are not abstract mathematical constructs, as you imply. The number $e$ is an abstract mathematical construct. The definition of units of time using an atomic clock is what you would describe as universal constants - you should be happy with this. It is definitely not abstract mathematics - it's hard physical experiment. – StephenG Jan 29 '18 at 20:00
• @Alchimista Can you have time without motion? How would you measure it? Motion of some object relative to another is required to create the concept of time as we like to think of it. Is it a property of matter or simply a tool we use to help understand our universe? So the deep answer is that Time is a construct that belongs to the human mind. You can't undo an event once it happens but in the mind you can imagine it. – PeterS Jan 29 '18 at 20:08