Post by Daleif everything has a wave/particle duality, what are the particles of
spacetime? and their anti-particles?
I don't think the standard particle model addresses this
The Natural or Planck Units seem to address this. A Planck Length seems
to be the ultimate smallest unit of space, while a Planck Time is the
ultimate smallest unit of time. It doesn't mean that you can't invent
numbers smaller than this, they simply won't have any meaning below the
Planck level.
It's a controversial subject, many traditionalists don't believe in
Planck units as being anything more than a mathematical curiosity. That
space and time must extend down infinitesimally. Others think Planck
Units are telling us something fundamental about the universe.
Superstring Theory, with all of its controversy, may be right about one
thing, it envisions its fundamental objects, the strings, as being about
1 Planck Length in size. Some of the strings may grow & inflate to
larger than 1 Planck Length, but none may shrink below it. Even if
Superstring Theory is disproved, this aspect may remain in any other
next-generation theory.
My own take on this is that space and time are just our way of
interpreting the minimum distances between particles (either energy or
matter), and the minimum movements of these particles, respectively. If
no two particles of anything can occupy the exact same space, then the
Planck Length is the minimum space between any two particles. If
particles are moving about, the minimum movement step would have to be
between two adjacent Planck Lengths, and the amount of time that passes
between these two steps is the Planck Time.
Post by Daleif space is "nothing", what is on the other side of "nothing", more
"nothing"? space would be some set having a cardinality/ordinality of
infinity, but "nothing" is the null-set and would only exist in
philosophical logic and philosophical mathematics, this is a contradiction
Space is a very special nothing, because it's filled with lots of stuff.
Our traditional definition of a vacuum was any volume of space that has
no matter in it. Well as of Einstein's Special Relativity, we've known
that matter is just a special form of energy (it's a phase of energy,
much like ice is a phase of water). Then as of the advent of Quantum
Mechanics (especially Quantum Electrodynamics) we've known that space
must be filled with energy -- huge amounts of energy as a matter of
fact. We call this energy the Quantum Vacuum Energy, or just Vacuum
Energy. This energy just exists because space exists: if space didn't
exist, this energy wouldn't exist either. So since we know matter and
energy are the same thing, if space is filled with energy everywhere,
then there really can't be any real vacuum anywhere in the universe.
Now think of my wording up above, "if space didn't exist, this energy
wouldn't exist either". This implies that space must exist as a
something. There doesn't exist a true nothingness. Mathematicians have
something that's less than nothing, which they call a null set: it's a
true zero, it's entirely abstract, just exists as a thought experiment.
But a true zero doesn't actually exist in this universe (or any other).
Post by Dalewould have to study the mathematics of general relativity to see how
time is proposed to fit in here ...
Time is a dimension just like any of the spatial dimensions, but it
happens to be the direction in which movements are measured. During the
Big Bang, this is the direction that was randomly chosen for the
momentum of the Big Bang to express itself.
Yousuf Khan