Newton Revisited

[sluggo]

Newton's first rule (no one knows the law) of motion: "A body remains at rest, or if in motion, remains in motion at a constant speed in a straight line, unless acted upon by an external force."

Here Newton, in typical two valued logic, defines 'rest' and 'motion' as opposites, eg., light-dark, hot-cold, sweet-sour, etc. As a real world example, six jets are performing aerobatic formation flying at 300 mph. Excluding minor air turbulence, non are moving relative to the other five. The point is they are at rest relative to the formation, yet simultaneously in motion relative to the ground.

If Newton's first rule is modified to: "A body is at rest relative to second body, if both have the same velocity", then all bodies are in motion, and rest is just a special case of motion. It works well in a dynamic universe.

The purpose of this idea is to avoid the need to search for the elusive 'absolute rest frame'.

 

[JMJones0424]

The purpose of this idea is to avoid the need to search for the elusive 'absolute rest frame'.

 

I don't know that this need was either imagined or addressed by Newton, as he assumed an absolute rest frame existed without evidence as he assumed that the passage of time is constant.  Instead, what the first law describes is the concept of inertia.  If a mass is moving, then it won't stop moving without a force applied to it.  If a mass is stationary, then it won't move unless a force is applied to it.  You needn't invoke an absolute rest frame to understand this, as the only frame of reference is that of the mass that either is or is not forcefully moved.  In order to change the state of motion of a mass, one must accelerate it.

 

http://hyperphysics.phy-astr.gsu.edu/hbase/Newt.html#nt1

Edited May 9, 2018 by JMJones0424

[sluggo]

SR is built on the same fact that only a change of motion is detectable. It's not an issue about inertia.

My point is, there is no need for an absolute rest frame.

[JMJones0424]

My point is that your claim is false.  Specifically, you are making a false claim here:

 

 

Here Newton, in typical two valued logic, defines 'rest' and 'motion' as opposites, eg., light-dark, hot-cold, sweet-sour, etc. As a real world example, six jets are performing aerobatic formation flying at 300 mph. Excluding minor air turbulence, non are moving relative to the other five. The point is they are at rest relative to the formation, yet simultaneously in motion relative to the ground.

If Newton's first rule is modified to: "A body is at rest relative to second body, if both have the same velocity", then all bodies are in motion, and rest is just a special case of motion. It works well in a dynamic universe.

The purpose of this idea is to avoid the need to search for the elusive 'absolute rest frame'.

 

Newton's first law makes no assertion about frames of reference at all.  I don't understand what you are trying to shoe-horn in.  Newton's first law simply states that in order to change the motion of a massive object, one must accelerate it.

 

Of course there's no need for an absolute rest frame.  Imagine the universe is void except for you in a spacecraft.  You can not determine what velocity you are traveling.  The concept of you having a velocity in an empty universe is meaningless.  However, in order to change your unmeasurable velocity, you must accelerate.  This is Newton's first law.  I think you are reading far too much into it.

 

Edit: Your example of jets flying in formation is absolutely wrong.  Jets do not fly without continuous force being applied.  Even if a jet did cut power, there would be aerodynamic forces and gravity changing its velocity.  Relative location of jets in formation has nothing at all to do with Newton's first law.  You are simply wrong.

 

Given the fact that you have exhibited a fundamental lack of understanding of what Newton's first law is, and that you've failed to provide any reason to believe that you are anything more than a self-assured crank, I find your unsupported  critique of special relativity useless.

 

Newton's first law is only about inertia. 

http://hyperphysics.phy-astr.gsu.edu/hbase/Newt.html#nt1

 

 

Don't be a crackpot.  Newton did not make any claims about SR.  If anything, he argued against it, as he assumed constant time.

 

 

 

SR is built on the same fact that only a change of motion is detectable. It's not an issue about inertia.

  I disagree.  SR is simply an extension of Gallilean relativity added with the fact that the speed of light is measured to be the same regardless of one's relative motion to another observer.  Newton's first law doesn't address this at all.  I don't think you know what Newton's first law is.  https://en.wikipedia.org/wiki/Newton%27s_laws_of_motion#Newton's_first_law

 

 

 

My point is, there is no need for an absolute rest frame.

Well, that's quite fortunate, as neither Newton's first law nor SR requires such a thing.

 

Since you are making so many positive assertions of clearly false ideas, I can't help but wondering if you don't understand what an inertial frame is. https://en.wikipedia.org/wiki/Inertial_frame_of_reference.

 

You can imagine that a frame of reference is the map that one uses to navigate the Universe.  It is the set of coordinates that you use to determine the location of all actions in your past and predict all actions in your future.  It is a frame of reference (map) that is homogeneous (identical to all others that follow your path) and isotropic (the path is the same regardless of how you orient the map).

 

An inertial frame of reference such as that described in special relativity and that referred to in Newton's first law is decidedly not an absolute rest frame.  Using SR, it is easy to show that such a thing cannot exist, as the speed of light is constant.  Instead, an inertial frame of reference is the map that you follow if you have no accelerating forces acting on you, but there can be no absolute rest frame map to compare your inertial map to.  If there was, this would be called the aether.  The non-existence of aether predates the discovery of SR.  There is no and can be no absolute map[b/] .  Instead, all maps are useful only to those in their inertial frames, and using SR and GR, we can transform coordinates from one inertial frame to another.

 

In my analogies above, it may help to consider a "map" as being a snapshot of a videogame frame such as Asteroids  The important thing here is that an inertial frame is the description of your movement through the cosmos without acceleration.

 

After many edits and re-reading, I'm afraid my attempts at clarification may not be sufficient.  Please review Ned Wright's tutorial on relativity: http://www.astro.ucla.edu/~wright/relatvty.htm

Edited May 19, 2018 by JMJones0424