[Alamo-Girl]

Er, I was eavesdropping on your ”what is time?” discussion with Consort and would like to offer something to think about.

On the one hand, we have time dilation which shows that

”A clock in a moving frame will be seen to be running slow, or "dilated" according to the Lorentz transformation. The time will always be shortest as measured in its rest frame. The time measured in the frame in which the clock is at rest is called the "proper time".

On the other hand, we have gravitational time dilation which shows that ”A clock in a gravitational field runs more slowly according to the gravitational time dilation relationship from general relativity “

Indeed, recent studies in string theory suggest that gravity is a multidimensional interaction, and whether you are inclined to a brane theory or a 5 dimension theory – the conclusion is that matter is the result of geometry (induced by STM or total by symmetric brane.) Whether the extra dimension is space-like or time-like is a matter of sign and thus, transforms.

Also, a null path in 5D can appear as a time-like path in 4D.

In sum, Consort responds to boris:

Maybe space-time is nothing, and matter-energy is everything. Space could be a void and time could be no more than a measure of duration of movement. Matter and energy are real.

I believe Consort is on the right track, but I propose a near inverse; that matter/energy and thus, our 4D concept of "time passing" --- are but the manifestation of geometry (higher dimensional dynamic.)

[Consort]

Time dilation seems to be just another way of saying that the intervals change in some matter-energy events under varying conditions.

[boris]

"Er, I was eavesdropping on your ”what is time?” discussion with Consort"

How dare you?...

Anyway, I'm aware of the Kaluza-Klein 'breakthrough' and somewhat familiar with brane theory, et al.

But not mathematically sophisticated that these theories 'explain' time to a simple engineer.

My readings on Time have taken me in many different directions (but not dimensions). Recently I've been reading extensively on Buddhism (no, a 51-year-old Jew is not going to convert to Buddhism). As I mentioned I've read Barbour and others extensively but they have not helped.

In a way it is presumptious to claim that human can in principle understand time, or that in principle we can claim to have 'complete' understanding of it. As I said, I suspect we are simply not the kind of creatures which can contain such understanding, all posturing to the contrary not withstanding.

Many of the books I've read on Time now seem like so much bafflegab; only Barbour and a few others seem to stick in my mind, to be turned over and over like a child examining a shell on the beach.

I am deeply confused and humbled, but it keeps me out of trouble.

--Boris