Is time a real quantity in physics or a convenient mental construct?

Question

I speculate that time was 1st noted by primitive man when he unavoidedly noticed that plants grew well when it got warm but not when it was cold; he would notice that bears hibernated and many other anumals seemed scarce when it was cold. He noticed the phases of the moon, 12 or so complete cycles each complete warm/cold cycle. He could not help but distinguish between day and night. Man as symbolizer gave these phenomena names. As he learned to devise tools, he made a sundial to divide a complete day/night cycle into sections probably to improve communication. As tool making improved, man contrived mechanical clocks and moved on to atomic clocks and maybe something even more sophisticated. But time is still a mental construct just as mathematics is. Without man -- no mathematics ... no time. Then , how can time be a real variable quantity? Being a mental construct, man can fit it into any mental construct in a manner convenient to any theory like relativity.

Answer 1

That time is a fundamental physical dimension is fundamental to, and is supported by, all of science. More specifically, time is qualitatively different from, but not separable from, spatial dimensions. That's a key aspect of general relativity, and why we now speak of spacetime.

Answer 2

It's a real physical construct, yes.
If it wasn't, time dilation and all that other stuff wouldn't occur.

Time is a variable, because general relativity states that matter can warp both space and time. As one gets closer to the speed of light, the shorter time becomes.
Example:
The twin paradox.

Time dilation occurs in places of extreme gravity (like a black hole) where time could stop so much that a second could take an eternity.
If you travel at the speed of light, time becomes non-existent. You could travel to the Andromeda Galaxy and for you it would take an instant, although in reality it would be 2 million years.

Answer 3

Plants grew long before man was around to notice them. The seasons happened even back in 100 million B.C.E. Day and night have been happening since the Earth was formed.

Time is as real as distance, or mass, or other physical quantities.

Answer 4

Yes time is a real quantity, it's just intangable just like distance or thoughts. Think back to the creation of the universe "the big bang" which is an akward term to use be cause this explosion had nothing to explode in to it was more of an expansion and before this time did not exist and neigther did space

Answer 5

only greater physics jargon ... i'm no longer even confident if that's authentic anymore ... Photons and gluons are strictly massless. they are the gauge fields of unbroken symmetries (no longer only like the vulnerable vector bosons). using reliable stress and the self-interactions of the gluons (the reliable stress originates from a non-Abelian team -- so there is self interplay between the gauge fields -- the gauge fields themselves are charged), there may be gluon condensation and the condensation seems great. As they are massless, they do no longer immediately work together with Higgs boson on the tree-point. At larger-loop tiers, there are interactions considering you have all varieties of digital debris (i.e. debris that are no longer 'on-shell'). an identical possibly is going for the interactions with gravitons (the particle interpretation of the gravitational field). Photons curve around great bodies. Photons can no longer get away black holes as quickly as they are interior the form horizon of the black holes. in spite of if, those 2 issues are truly self reliant, till the curvature of the photon trajectory is brought on by utilising the black hollow.

Answer 6

Is length a "mental construct"? Weight? Temperature? These too are "real variable" quantities that are constructs of man to categorize, catalog, and otherwise logically sort things. Everything that man can observe or measure is a "mental construct." What of it, how does this negate that a thing exists?

Answer 7

You bring up a very interesting point. The fact is, no one really knows what "time" is. Humans measure physical variables in terms of other physical variables. The swing of a clock pendulum, or the tick of a cesium atom in an atomic clock are just physical consistencies that are used to measure constant amounts of this mysterious "time." So time may not even exist. perhaps it is just a trick of our minds. As the world changes, we perceive the illusion that time is passing by. Then again, maybe not. As I said, no one knows what time is. It's a nice topic to ponder over.

Answer 8

time exists but is flexable.
time can be considered relative. - is relative.
this can be measured and predicted therefore can be included in mathematics as real.
experiments with atomic clocks etc have been done.
we know the basics so time can be included in calculations with its variations taken into account.
time is real in physics and necessary.