I Which theory of time is the most evidence-based?

[PeterDonis]

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[PeterDonis]

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[bhobba]

Thank you very much for your detailed reply. I don't understand what space-time is. What is it made of? Isn't space just emptiness? As far as I know, at the speed of light, time stops. How does that work? I am sorry if my questions are silly - they reveal how little I understand!

The thread is shut.

Here's a comparison that might help. Remember geometry from school? Points have position but no size and a line length but no width. Such do not exist. They are abstractions. It talks about points and lines that exist in theory but not in the physical world. They're the building blocks of geometry, abstractions that help us understand the real world. Similarly, space-time is a theoretical construct that helps us make sense of the universe.

Every theory, every single one, is like that. They contain abstractions used in the theory. If you succeed in finding something deeper that either explains those concepts or somehow replaces them, in a sense, you have not got anywhere because what you replace it with has the same problem. Absolute knowledge is beyond science's grasp.

For time, like point and line, we all have an intuitive idea of what it is. To make it more precise, we need what is called an inertial frame. A frame is simply a standard of rest on which experiments can be conducted. An inertial frame has a special property - the laws of physics (again, an abstraction) are the same in any direction, at any point, or at any time. The earth is an approximate inertial frame. Suppose we have some repetitive process and count the number of times it occurs. Repetitive process is a fundamental abstraction. But since the laws of physics are the same at any point, time, or direction, we have a way to assign a number to the time it is anywhere in the frame. The count of the repetitive process measures time and is called a clock. This is the idea time is what a clock measures.

I will mention I am reading a book now that explains time at a deeper level, but it is advanced and needs as background what I wrote above:



Thanks
Bill