🚀 go-pugleaf

On May 1, 3:52 pm, Yanick Toutain <YanickTout...@gmail.com> wrote:
> On 2 mai, 00:17, Michael Helland <mobyd...@gmail.com> wrote:
> Michael Helland wrote : "in static space. "
>
> Do you really think that ?
> "in static space. "
> You agree with absolute space of Newton ?

My point was that it is not expanding.

That's what I meant by static.


> It is the beginning of philosophy, the beginning of science.
> It is the beginning of Newton's Principa ?
> You agree?


The beginning of Newton's Principia defined time and space as being
both absolute and relative:

<quote>
I.  Absolute, true, and mathematical time, of itself, and from its own
nature, flows equably without relation to anything external, and by
another name is called duration:

relative, apparent, and common time, is some sensible and external
(whether accurate or unequable) measure of duration by the means of
motion, which is commonly used instead of true time; such as an hour,
a day, a month, a year.

II. Absolute space, in its own nature, without relation to anything
external, remains always similar and immovable.

Relative space is some movable dimension or measure of the absolute
spaces; which our senses determine by its position to bodies; and
which is commonly taken for immovable space; such is the dimension of
a subterraneous, an aerial, or celestial space, determined by its
position in respect of the earth.
</quote>


Furthermore, Einstein never disputed absolute/relative duality of
space and time.

He only pointed out that the subject of our equations and observations
are relative space and time.

He writes in Relativity Chapter 9:

<quote>
Now before the advent of the theory of relativity it had always
tacitly been assumed in physics that the statement of time had an
absolute significance, i.e. that it is independent of the state of
motion of the body of reference. But we have just seen that this
assumption is incompatible with the most natural definition of
simultaneity; if we discard this assumption, then the conflict between
the law of the propagation of light in vacuo and the principle of
relativity (developed in Section VII) disappears."
</quote>

The reason for the assumption could be Newton's description of
absolute time being mathematical rather than relative time.

In Chapter 8, Einstein gives his working definition for time:

<quote>
Under these conditions we understand by the 'time' of an event the
reading (position of the hands) of that one of these clocks which is
in the immediate vicinity (in space) of the event
</quote>

Einstein is defining time in terms of the moving hands of a clock,
which is nearly identical to how Newton defined relative time:

<quote>
Relative, apparent, and common time, is some sensible and external
(whether accurate or unequable) measure of duration by the means of
motion, which is commonly used instead of true time; such as an hour,
a day, a month, a year.
</quote>

Newton's definitions came from Descartes, and the ideas go back to the
Greek Monists.