In Newtonian Mechanics, objects change their state of motion by being
affected by a force that results due to the presence of another
object. In General Relativity, objects move inertially but their
motion is dictated by the curvature of space-time. Is there any other
( and better ) explanation or a conception of why objects move ??

Thanks
http://physicsroots.blogspot.com

On May 12, 9:11 am, wrote:
In Newtonian Mechanics, objects change their state of motion by being
affected by a force that results due to the presence of another
object. In General Relativity, objects move inertially but their
motion is dictated by the curvature of space-time. Is there any other
( and better ) explanation or a conception of why objects move ??

Thankshttp://physicsroots.blogspot.com

You are not reading your own words carefully. Motion in itself is not
the result of anything. It is *purely* an artifact of choice of
reference frame. There is *nothing* physically that distinguishes
something that is moving through space from something that is not
moving through space.

The ONLY thing that dynamical laws of physics tell you is how a
*change* in motion is produced. This is precisely what you said (more
or less correctly) in your first two sentences. Understanding this
statement is central.

To carry it one further step, what this means is that there is
*nothing* physically that distinguishes a change of motion [moving]-
[not-moving] from [not-moving]-[moving]. Once again, those
characterizations of the *same* physical process are simply an
artifact of choice of reference frame.

PD

wrote:

In Newtonian Mechanics, objects change their state of motion by being
affected by a force that results due to the presence of another
object.

http://en.wikipedia.org/wiki/Pauli_exclusion_principle

In General Relativity, objects move inertially
but their motion is dictated by the curvature of space-time.
Is there any other ( and better ) explanation or a conception
of why objects move ??

GR is more of a description of the effect
than an explanation of the cause;
it's a very good description from what I hear.

Connecting these two effects is apparently an
on-going problem:

http://en.wikipedia.org/wiki/Quantum_gravity

You are not reading your own words carefully. Motion in itself is not
the result of anything. It is *purely* an artifact of choice of
reference frame. There is *nothing* physically that distinguishes
something that is moving through space from something that is not
moving through space.

The ONLY thing that dynamical laws of physics tell you is how a
*change* in motion is produced. This is precisely what you said (more
or less correctly) in your first two sentences. Understanding this
statement is central.


PD

Ok. It seems that I put the question this way to make you understand
that I know such simple facts:
Why do non-moving objects in the frame of PD move in the frame of PD ?

Tareq
http://physicsroots.blogspot.com/

On May 12, 10:05 am, wrote:
You are not reading your own words carefully. Motion in itself is not
the result of anything. It is *purely* an artifact of choice of
reference frame. There is *nothing* physically that distinguishes
something that is moving through space from something that is not
moving through space.

The ONLY thing that dynamical laws of physics tell you is how a
*change* in motion is produced. This is precisely what you said (more
or less correctly) in your first two sentences. Understanding this
statement is central.

PD

Ok. It seems that I put the question this way to make you understand
that I know such simple facts:
Why do non-moving objects in the frame of PD move in the frame of PD ?

In other words, what causes a change in motion?

Another object in the frame of PD interacts with the first object.

Which fundamental interaction is at play makes a difference, but there
are at least three *completely* different ways of looking at any
interaction, and these different ways are completely equivalent and we
cannot really say which one is better than other or more "right" than
another. They are just different ways of thinking about the same
thing.

For the electromagnetic interaction, for example, you can look at the
interaction as being mediated by quantized fields (photons and charged
particles), where the behavior of the quanta obeys the principle of
least action.

Einstein said that gravity is special in that it can be thought of as
a distortion of spacetime (the four dimensions that we live in)
itself.

Now, the electromagnetic interaction can also be thought of as
distortions of some dimensions, just not the same spacetime dimensions
but other ones.

Likewise, there are those who believe that eventually we'll work out
the correct model for gravity being mediated by quantized fields that
obey the least action principle. That hasn't been demonstrated yet.

Which one is "right" -- quantized fields, or distortions of dimensions
that the objects live in -- is probably not even a sensible question.

PD

On May 12, 10:11 am, wrote:
In Newtonian Mechanics, objects change their state of motion by being
affected by a force that results due to the presence of another
object. In General Relativity, objects move inertially but their
motion is dictated by the curvature of space-time.

That's only true for inertial forces. Impulse forces can still exist
in GR. So motion can be dictated by both.

Now, the electromagnetic interaction can also be thought of as
distortions of some dimensions, just not the same spacetime dimensions
but other ones.
Could you mention some reference ?
Is this the third way to look at an interaction ?

Tareq
http://physicsroots.blogspot.com/

wrote in message
oups.com...
In Newtonian Mechanics, objects change their state of motion by being
affected by a force that results due to the presence of another
object.

Not true eg fields can also do it.

In General Relativity, objects move inertially but their
motion is dictated by the curvature of space-time. Is there any other
( and better ) explanation or a conception of why objects move ??

Yes - fields. The 'field' of GR is space-time curvature, which gives
different values of the metric, and that determines a particles motion.

Bill


Thanks
http://physicsroots.blogspot.com

"Tareq" wrote in message
ups.com...
Now, the electromagnetic interaction can also be thought of as
distortions of some dimensions, just not the same spacetime dimensions
but other ones.
Could you mention some reference ?
Is this the third way to look at an interaction ?

Tareq
http://physicsroots.blogspot.com/


Check out
http://astro.uwaterloo.ca/~wesson/

This stuff really is right at the cutting edge of current research.

Thanks
Bill

Changes are laws of motion/nature.Systems move in order to achieve
equilibrium.In relativity ,electromagnetic,strong,weak,
nuclear ...every type of interaction movement of particles occur to
result new systems ,again whose aim is to attain stability through
various dynamics.

On May 13, 6:38 am, Tareq wrote:
Now, the electromagnetic interaction can also be thought of as
distortions of some dimensions, just not the same spacetime dimensions
but other ones.

Could you mention some reference ?
Is this the third way to look at an interaction ?

Tareqhttp://physicsroots.blogspot.com/