[jeffreyH (OP)]

I think not but it would be interesting to get other views on the subject.

[Colin2B]

Momentum can, which implies kinetic energy

[jeffreyH (OP)]

For a Lagrangian we only need to consider kinetic and potential energies. The rest energy is not involved. This is due to the equivalence of inertial and gravitational mass. The energy is that of motion. You do not require motion to have a gravitational field. If the strength of a gravitational field depends upon the motion of its source I don't know what the implications would be.

[Colin2B]

Are you thinking of something other than, dare I say it, relativistic mass?

[jeffreyH (OP)]

Are you thinking of something other than, dare I say it, relativistic mass?

Well the Lorentz factor is real as demonstrated by time dilation. The question is which side of the equation does it belong on when determining force? You could argue that it makes no difference as it is unitless.

[jeffreyH (OP)]

You could also ask why am I nit picking?

[jeffreyH (OP)]

Say we define the following equation.



Where F is force, p is momentum and t is time. The Lorentz factor is applied to the force in a frame moving relative to an inertial observer. This requires no function to be applied to momentum.

[jeffreyH (OP)]

As a final note on this we can define the Lorentz factor as

This conclusion is arrived at by showing that the equation is homogeneous.

[jeffreyH (OP)]

The speed would make a difference inasmuch as there is a difference between a circular and elliptical orbit due to a difference in velocity. So the effect of the field is affected by relative velocity. The above implies an effect on force carriers due to an increasing velocity. This is the root of time dilation.

[geordief]

The speed would make a difference inasmuch as there is a difference between a circular and elliptical orbit due to a difference in velocity. So the effect of the field is affected by relative velocity. The above implies an effect on force carriers due to an increasing velocity. This is the root of time dilation.

By "force carriers" do you mean gravitons?

[jeffreyH (OP)]

Any force carriers. For the strong, weak, electromagnetic and gravitational fields. Why do things continue to move in a straight line at constant velocity? Is this connected to the speed of light? What are the mathematics that would show this? Just a few topics for conversation.

[jeffreyH (OP)]

As things become more complex you run into the n-body problem. This applies to much more than elementary particles.

[geordief]

. Why do things continue to move in a straight line at constant velocity? Is this connected to the speed of light? What are the mathematics that would show this? Just a few topics for conversation.

If there is any predictability at all in physics then one ongoing  measurement  must surely be the same as the previous one if conditions are unchanged.**

That defines a straight line perhaps .which can be a curved line provided the curvature is constant.

So a straight line can be seen as analogous to logical  reasoning. No straight lines ,no reliable mental
 constructs possible..

Of course if our collective mental constructs are somehow flawed at  "base camp" then our understanding of our surroundings also start with that handicap.

But I think we can believe (a faith?) that our mental constructs and our physical environment are "joined at the hip" even if the union  is obscured from our understanding.

I have no idea what mathematics might be brought to bear on my assertions(or if they have any merit) but "straight lines" is an interesting topic.

**edit: on reflection that  is certainly not irrefutable

[opportunity]

As things become more complex you run into the n-body problem. This applies to much more than elementary particles.

Really? The n-body problem is pitched at celestial objects resolving GR and SR issues. That's like saying ice cream is cold. How do things become more complex than the elementary particle level there? Wouldn't you want to solve the elementary particle level first?

[jeffreyH (OP)]

@opportunity The Higgs particle is distinct from the Higgs mechanism. The Higgs mechanism is responsible for part of the mass of nucleons. In that respect it has a link to inertia. I am not sure how that is linked to kinetic energy.

@geordief I think you need to clarify your thoughts. I would have a look at classical mechanics and Newton's laws.

[jeffreyH (OP)]

The n-body problem applies to objects at all scales since the important thing is the force or forces involved. BTW anything stationary has zero kinetic energy. You have internal system energies in the form of oscillations.

[geordief]

@geordief I think you need to clarify your thoughts. I would have a look at classical mechanics and Newton's laws.

You mean my thoughts should be  more focused here?
Is your question about straight lines restricted to classical physics (are there any straight lines in quantum physics?)

[jeffreyH (OP)]

. Why do things continue to move in a straight line at constant velocity? Is this connected to the speed of light? What are the mathematics that would show this? Just a few topics for conversation.

If there is any predictability at all in physics then one ongoing  measurement  must surely be the same as the previous one if conditions are unchanged.**

This may be true at the microscopic scale and in quantum mechanics but at macroscopic scales relative motion has to be taken into account.

That defines a straight line perhaps .which can be a curved line provided the curvature is constant.

So a straight line can be seen as analogous to logical  reasoning. No straight lines ,no reliable mental
 constructs possible..

I can see why you are considering curvature as representing a straight line since this describes the way geodesics relate to geometry. The second sentence isn't clear.

Of course if our collective mental constructs are somehow flawed at  "base camp" then our understanding of our surroundings also start with that handicap.

But I think we can believe (a faith?) that our mental constructs and our physical environment are "joined at the hip" even if the union  is obscured from our understanding.

I have no idea what you mean here. At least not in scientific terms.

I have no idea what mathematics might be brought to bear on my assertions(or if they have any merit) but "straight lines" is an interesting topic.

**edit: on reflection that  is certainly not irrefutable

[opportunity]

Ok, so you're looking large scale and not small. I know what you're asking about massive celestial objects, and you know "should that hold true" on the elementary particle level?

[geordief]

@jeffreyH
The quote function has defeated me this time  and so  I will still try to answer as best I can.

I felt  ,in contradiction to you that straight lines should apply more to classical physics than quantum physics.



Also to your quote "The second sentence isn't clear." I was meandering  from the question  but ,in that a straight line can be seen as one (unit) step followed  by another  then there is a superficial similarity to steps in logic. But this was probably not particularly helpful or useful .

Actually my initial thought regarding straight lines was to bring up extremal aging but I have yet to understand that concept very well and so steered clear of parading this additional  aspect of my ignorance.