Time, space and matter (when I say matter I include energy and electric charge) are all real quantities that exist in our universe. Time and space form the geometry that governs matter which is the interaction of all physical or tangible reality. As such, it is ever present and never absent. It is impossible to describe any real system in our universe without time, space, and matter/energy
in the description.
Consider the possibility of measuring matter and space without time. Without time there is no physical existence, no temperature, no properties of matter to measure - such a thing is impossible. Consider measuring time and matter without space. Impossible to measure something that has no space to exist. Considering time and space without matter is more difficult- but when Einstein developed general relativity it truly showed the impossibility. I won’t get into the particulars except to point you here:
Hole argument where it is described that distance cannot be though of as separation of coordinates only, but require two test particles.
I therefore believe nothing is more basic, more real, and more necessary to our universe than space, time, and matter. Nothing is real if it lacks any one. As an example, here is your description of time:
Quote:
Originally Posted by steve 9
Time is actually a consideration based on our perception of the movement of objects. There is a distance, there is a velocity of the objects travel, and that movement of that object or particle in relationship to its starting point and in relationship to its ending point is what gives us the idea of time.
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You use two words here “movement” and “velocity” to describe time. Velocity is change in space over change in time. Your definition of time therefore recognizes the necessity of its existence.
As both your definition of time and my idea of time require it to be real we have a common footing from which to advance this subject productively. The next question becomes: what are the properties of space and time. As you say:
Quote:
Originally Posted by steve 9
What do they look like? Do they have a color? Are they a wave or a solid? From where do they eminate? How much space do they occupy? How long is it? How wide is it?
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The examples you give, however, are properties of energy and matter. Space and time are fundamentally different from matter and energy therefore none of these properties apply. Space and time have different properties that equally would not pertain to matter and energy.
I can give some properties of spacetime, but I must qualify this by saying - some of these properties are perhaps only applicable to the model describing spacetime while others clearly apply to space and time themselves.
- all dimensions are orthogonal to other dimensions
- Time is different from space in a manner reflected here:
- Time and space describe motion (a geodesic)
- Time and space influence gravity
- Energy curves spacetime
- Time is not symmetric
- Time is unidirectional
- Space is not unidirectional
As you can clearly see, these properties are different from "color" and "solid" and the other examples you give.
Much of the history of physics is the discovery of these properties that pertain to the fundamental units and how they relate to one another. For example: What is the best way to describe force? Mass times acceleration has the units:
which is mass times space divided by time squared. Therefore it is very useful to understand how the fundamental units interact. To understand relativity and time dilation we need to understand the structure of spacetime. The consistency of the speed of light is a property of space, time, and matter. The relationship Einstein gave these things as matter moves is very insightful and very useful.
I guess to sum up, I'd say space and time are physical. They are a necessary part of the universe and that makes them physical. But, they are not tangible - they do not share the properties of matter that would allow them to have that description.
Can you think of any useful ways of describing how these things relate to one another?
~modest
