u/Ok-Incident160

Did physics ever discover that one second has its particular duration, or did humans first choose the size of the second and then physics simply develop better and better ways to reproduce that same duration?

For example, the second was originally based on dividing a day into 86,400 equal parts, and later it was redefined using the cesium-133 atom. But the atomic definition was chosen to match the already existing second.

So my question is: has physics ever shown that one second must have that particular duration because of nature itself, or has it only replaced less accurate standards with more accurate ones while keeping the original human-defined duration the same?

Has physics ever calculated time itself, or has it only refined the way we measure an originally human chosen convention?

The radian is introduced through a specific geometric construction: the angle subtended by an arc whose length equals the radius (s = r).

My concern is the following:

The condition s = r appears to describe a particular geometric event rather than a fixed reference object or uniquely determined physical opening. The same condition can occur on circles of arbitrarily different sizes, producing different arc lengths, different physical spreads, and different apparent openings in space.

Yet mathematics identifies all such cases as the same angle (1 radian) and then extends this to the general formula θ = s/r, treating angle as a scale-independent quantity.

My questions are:

1.What is the logical justification for moving from the specific geometric event s = r to a general measurement system θ = s/r?

2.If the defining construction does not determine a unique physical spread or opening, in what sense does it define a single angle?

3.When geometry says an angle measures an "amount of rotation" or "amount of opening," what exactly is the quantity being measured, independent of the chosen measurement system (degrees, radians, etc.)?

The radian is introduced through a specific geometric construction: the angle subtended by an arc whose length equals the radius (s = r).

My concern is the following:

The condition s = r appears to describe a particular geometric event rather than a fixed reference object or uniquely determined physical opening. The same condition can occur on circles of arbitrarily different sizes, producing different arc lengths, different physical spreads, and different apparent openings in space.

Yet mathematics identifies all such cases as the same angle (1 radian) and then extends this to the general formula θ = s/r, treating angle as a scale-independent quantity.

My questions are:

1.What is the logical justification for moving from the specific geometric event s = r to a general measurement system θ = s/r?

2.If the defining construction does not determine a unique physical spread or opening, in what sense does it define a single angle?

3.When geometry says an angle measures an "amount of rotation" or "amount of opening," what exactly is the quantity being measured, independent of the chosen measurement system (degrees, radians, etc.)?

I was thinking about how we define a meter as a fixed distance. If I take that 'meter' and wrap it around a circle to measure an angle,the angle changes depending on the size of the circle.

But if I use 'radians', the angle stays the same while the distance changes.

Which one is the 'real' constant in nature the distance or the angle or it just a scaling ratio label as "1"

I was thinking about how we define a meter as a fixed distance. If I take that 'meter' and wrap it around a circle to measure an angle,the angle changes depending on the size of the circle.

But if I use 'radians', the angle stays the same while the distance changes.

Which one is the 'real' constant in nature the distance or the angle of it just a scaling ratio.

I was thinking about how we define a meter as a fixed distance.if I take that meter and wrap it around a circle to measure an angle,the angle changes depending on the size of the circle.But if I use 'radians' ,the angle stays the same while the distance changes.which one is the 'real' constant in nature the distance or the angle or is just scalling ratio...