http://www.perimeterinstitute.ca/pdf...b7e3-4a0914552
5ca.pdf
Albert Einstein: "I consider it entirely possible that physics cannot
be based upon the field concept, that is on CONTINUOUS structures.
Then nothing will remain of my whole castle in the air, including the
theory of gravitation, but also nothing of the rest of contemporary
physics."


There is a third possibility that has been ignored by all. The possibility
that space can behave as either continuous or discrete as it pleases.

THEN, even though you may have discrete models of reality, Einstein's Castle
in the Air would NOT be destroyed because physics will have two equally
valid and equally vast divisions, particle physics AND wave physics.

The continuity and/or discreteness of space can be modelled as being
INDETERMINATELY either one or the other. It is not both at the same time,
but merely one or the other as it pleases.

This does not invalidate Einstein's Castle in the Air. Nobody is going to
foreclose on Einstein's Castle. THE ROOF IS NOT LEAKING.

Subject: ROGER PENROSE, SPACE-TIME CONTINUUM,
ALBERT EINSTEIN

JanPB wrote:
Gerald L. O'Barr wrote:
Pentcho Valev wrote:
. . . .

O'Barr wrote:
. . . This math concept of there
being a spacetime continuum is only a math
concept, and it will never prove to be adequate
for any actual reality, on any level!

JanPB wrote:
It's just a model which is what physics deals with.
Look at Lagrangian or Hamiltonian or quantum
mechanics - they all use specific multidimensional
spaces as models. Spacetime is just another
instance of this old (1700s) general approach.

O'Barr comments:
What a breath of fresh air! Yes! This 4-D
spacetime continuum approach is just a math trick.
It is a math trick that works. That is all that it
is. Thank you, Jan, for being this honest. It is
about time that we have more honesty on this net.
Thanks, thanks, thanks!

O'Barr wrote:
Reality is reality, and it stands separate from
the math. If at any time science shows that this
math concept of a spacetime continuum does not
work on some small scale, then it absolutely is
not a valid physical concept on any larger scale.

JanPB wrote:
Well, sure. So what? Is any engineer going to
abandon Newtonian mechanics when designing an
airplane even if he knows full well that
Newtonian mechanics is not really correct?

O'Barr comments:
We are not asking for honesty out of the Engineer.
We are asking for honesty out of SR experts. For
those who write our FAQ. For those who write the
modern-day text books. There are many who do not
address this problem correctly. And most of those on
this net do not address this problem correctly.


O'Barr wrote:
. . . The math might
continue to work, just as the math works now,
but reality is reality, and if reality itself is
not 4-D on our deepest level, and/or if it is not
continuous, then it certainly is not 4-D on our
everyday level, and/or not continuous.


JanPB wrote:
Nobody says that "reality" is this or that.

O'Barr comments:
Now, now, Jan. That is exactly what SR experts
say. They say that because reality really is 4-D,
that is why things are the way they are.
You are saying what ought to be said, maybe, but
you are not being honest here. Can you quote the FAQ
where it says that 4-D is not our reality?


JanPB wrote:
Physics deals with mathematical _models_ which are
obviously understood to be a different thing than
reality.

O'Barr comments:
You are being very careless. For SR, this is
exactly the way things are. All you have in SR is
just a math model that correctly predicts
measurements when made in a specific way. You have
no concepts at all as to what actual reality might
be, to account for that math model.
But normal physics usually deals with physical
reality, and then seeks a math model to mimic that
physical reality. That is what LET is all about. It
assumes a physical reality. And from this physical
reality, it seeks and obtains the math that would
correctly model this physical reality. It is the
physical reality that is being certified, not the
math!



JanPB wrote about math models:
They are intellectual constructs with one useful
property: their contemplation by means of a certain
tool called "mathematics" yields results consonant
with events found in reality.

O'Barr comments:
Sounds correct. A better statement would simple
be to say that a math model allows one to make
predictions of the measurements that will be
obtained.

JanPB wrote:
Physics is a study of abstract models. Direct
experience of reality is something very different
and it doesn't employ any thinking - it's what
mystics talk about.


O'Barr comemnts:
Only an SR expert would try to pull this fun and
game out of your bags of tricks. Since SR is only
math, and thus SR cannot address any issue dealing
with actual reality, then the SR experts have tried
to change the meaning of a large number of words. SR
no longer likes the simple word mass. So you have
changed the meaning of the word mass. SR no longer
likes the simple concept of relative velocity. So
now relative velocity can only be that measured in
special frames, a frame in which one of the frames is
at rest with one of the velocities involved. SR no
longer likes the word science or physics. Science
and physics today cannot be allowed to be concerned
with an actual physical reality. Yes, Jan, you are a
sick person, and you have not been honest with me in
this post.

O'Barr wrote:
And we cannot allow such stupid thinking as this
to continue.

JanPB wrote:
What do you mean by "stupid"? This is just
childish arrogance. A model is not reality. It
was never intended to be.


O'Barr comments:
Yes, you now appear to want to be correct. But of
course, you still have not shown this concept
explained in the SR FAQ!


O'Barr wrote:
We do not have a 4-D spacetime reality.

JanPB wrote:
Oh brother. We have a model - a 4D Riemannian
manifold. It works as far as it was designed to
work. Sheesh.

O'Barr comments:
I do appreciate you present honesty. Why was it
so long in coming?


O'Barr comments:
We have no data (absolutely zero data) that shows
that we have anything except the simplest of 3-D.

JanPB wrote:
Nobody says otherwise. You are fighting windmills.

O'Barr comments:
No one says otherwise? Do you mean in not one of
hundreds of SR text books that have been written? Do
you mean not one out of the hundreds of Professors
that teach physics? Do you mean not one out of the
hundreds of SR experts on this net? Somehow Jan, you
are one lost soul, to just lie like this. Not one
person says that SR shows that we have a 4-D
spacetime continuum? You really mean this?


O'Barr wrote:
And anyone who tries to say that we have 4-D just
because we can force the math to work is silly and
do not deserve to be called scientific.

JanPB wrote:
You are again stating the beyond-the-obvious.

O'Barr comments:
I do know that the day is not far away when all
these SR experts, and their type of thinking, will be
laughed at. We will all laugh at anyone thinking
that there was an actual 4-D spacetime continuum. We
will laugh that people really thought that you could
have time tunnels, and go back in time. We will
laugh at anyone who thought that there could not be
an ether. We will laugh at all of you people who are
not realistic, and are not seeking for full cause and
effects within a physical reality.
You people have escape from reality, and you do
not deserve to be on this net. SR is one of the
weakest theories that have ever existed. Even if you
change the definition of hundreds of words, it just
will never be right.

Thanks for reading.
Gerald L. O'Barr