Continuing from where I left off -
One of the arguments, for why time
IS an illusion, springs from the fact that
Time can be reversed, in the laws of Physics. If the direction of the laws of nature can be reversed,
then there cannot, in principle, be any difference between the past and the future. Thus our common experience of time moving unidirectionally from the past into the future,
cannot be a fundamental property of nature and hence an illusion. They all spell the death of time as anything real.
Boltzmann “For the universe, the two directions of time are indistinguishable, just as in space there is no up and down.”
But, the experiments, which determine the laws of nature, are “
experiments in a box”, for
isolated systems, and we are
on the outside,
looking in. Our laws of physics,
like the second Law of Thermodynamics,
https://en.wikipedia.org/wiki/Second_la ... modynamics, which gives us
the thermodynamic arrow of time, applies to
isolated systems.
"
The principle of no isolated systems" springs from the fact that no system can be truly isolated from its surroundings, and
the cosmological fallacy, springs from the fact, that for
the whole universe, there is no outsider looking in. The probability laws apply for many instances of the same thing, The Universe is only one instance of one thing.
Thus they cannot be applied to the universe as a whole and, though fantastically accurate on regional scales,
are only approximations.
One of the arguments
that Time is real and fundamental comes from
Shape Dynamics,
Simultaneity of events can occur with adjacent or near objects. I get up and walk around, or hit a ball to you and you hit it back. But for objects far away, say on another galaxy, we cannot order events by time,
or by size. Your birthday might appear before Darth Vader's but Vader might say his does. Also, you might say you are
bigger than Vader and he might disagree.
So there was this guy, Julian Barbour, and a few other guys, (who discovered this problem about size), and found a solution to the problem -
Shape. Sizes may change,
but not shapes. If you are round, pudgy guy in andromeda galaxy, you will be round and pudgy here too, even if you change from the size of an elephant to that of a mouse. So now you could bring objects from different parts and compare them together. But, apparently,
there is a catch. The size of the Universe mustn't change. So if the guys shrink if they are brought here,
something somewhere else has to expand by the same amount.
And another thing about shape dynamics. Sizes can change,
but not time.
There has to be one single time for the whole universe! Remember Newton? This is the opposite to General Relativity, where sizes don't change but time does. These theories are more or less equivalent and derive from the same equations.
But shape dynamics,
in addition, "achieves an accord between the experimental success of the principle of relativity and the need for a global time demanded by theories of evolving laws and hidden-variable explanations of quantum phenomena." - This I have written down from Lee Smolin's book. (The rest is from my notes). There is no disagreement with SR time dilation in inertial frames smaller than those of the universe.
"if time is real, in the sense of a real present moment, there is a boundary all observers can agree on between the real present and the not yet real future. This implies a universal, physical notion of simultaneity that includes distant events and, indeed, the whole universe." This Smolin calls
Preferred Global time.
It does not require the discard of SR, just a modification of its equations. (?) I think I'm right on this - the modification.
"one quantity not allowed to change when you expand and shrink scales is the overall volume of the universe at each time.
This makes the overall size of the universe and its expansion meaningful,
and this
can be taken for a universal physical clock.
Time has been rediscovered."
