How is c the speed limit???

[crawler]

Aetherists probly reckon that a body cant attain the speed of light in the aether, ie relative to the aether. But why & how???

Some Einsteinists reckon that a body cant attain the speed of light relative to another body because relative mass increases with relative speed & a speed of c would result in an infinite relativistic mass.

I have been reading science for say 13 years. Today i reckon that the mass of a body does not change due to speed, ie i dont believe in relativistic mass in that Einsteinian sense. Hence if relativistic mass or some other kind of mass doesnt increase with speed then how can c be the speed limit???

To help find out i have been re-reading my printed papers re E=mcc. I see reference to various kinds of mass -- the mass, ordinary mass, ordinary Newtonian mass, proper mass, normal mass, gravitational mass, inertial mass, effective mass, relativistic mass, relativistic gravitational mass, rest mass, apparent mass, observed mass, perceived mass, relative mass, transverse mass, longitudinal mass, total mass, equivalent mass, scalar mass, point mass, infinite mass, zero mass, massless, imaginary mass, fictitious mass, indestructible mass, invariant mass, invariant proper mass, energy mass, momentum mass, speed dependent mass, electrodynamic mass, electromagnetic mass, charge mass, mechanical mass, heat mass, intrinsic mass, created mass, transferred mass, non-vanishing mass,

And i see mention of proper mass density, spacetime volume element, longitudinal volume dilation, spacetime bulk modulus, spacetime volume dilation, invariant longitudinal volume dilation, variation in mass, massless, conversion of mass, mass increase, increment of mass, mass point, mass of matter, mass of radiation, inertia of energy, etc.

I will have a think & get back.

[paladin17]

Some Einsteinists reckon that a body cant attain the speed of light relative to another body because relative mass increases with relative speed & a speed of c would result in an infinite relativistic mass.

One can also argue that the reason is an intimate connection of c with space-time geometry in special relativity. FTL speeds can easily lead to the breaking of causality.
Regarding mass, it is worth to note that in modern formulations of special relativity mass does not change - it is a 4-scalar. I.e. when you shift from one reference frame (in space-time) to another, mass of a body remains the same. What that effectively means is that mass is no longer a measure of inertia - the latter is now being dependent on kinetic energy.

[crawler]

I read that Einstein in later years did not believe that the relative speed of a body affected its mass. In other words that its kinetic energy did not add to its mass. I think that that meant that he believed in rest mass, & that somehow the internal energy (eg heat) added to rest mass to give a total (inertial) mass.

If the above is true then i dont see how post 1906 Einsteinists can claim that c is the speed limit.
Aetherists are in the same boat, however Aetherists have potential fixes, because Aetherists can fall back on physics & mechanics, whereas Einsteinists dont have any available obvious fixes.

So, pre 1906 Einsteinists can claim that an increase in relativistic mass makes c a speed limit.
But what do post 1906 Einsteinists say it is that makes c a speed limit???

[crawler]

Some Einsteinists reckon that a body cant attain the speed of light relative to another body because relative mass increases with relative speed & a speed of c would result in an infinite relativistic mass.

One can also argue that the reason is an intimate connection of c with space-time geometry in special relativity. FTL speeds can easily lead to the breaking of causality.
Regarding mass, it is worth to note that in modern formulations of special relativity mass does not change - it is a 4-scalar. I.e. when you shift from one reference frame (in space-time) to another, mass of a body remains the same. What that effectively means is that mass is no longer a measure of inertia - the latter is now being dependent on kinetic energy.

Mightbeso. But Einstein post 1906 said that the relative speed of a body (ie kinetic energy) did not add to rest mass (for most purposes i guess), but i think that he said that internal energy (heat)(ie kinetic energy) did add to rest mass (for most purposes i guess)(including inertia).

So, have post 1906 Einsteinists a fix that makes c the speed limit???

[paladin17]

But Einstein post 1906 said that the relative speed of a body (ie kinetic energy) did not add to rest mass

This is a tautology.

So, have post 1906 Einsteinists a fix that makes c the speed limit???

See my post above.

[crawler]

But Einstein post 1906 said that the relative speed of a body (ie kinetic energy) did not add to rest mass

This is a tautology.

It might be a tautology, but it agrees with what Einstein said exactly.

So, have post 1906 Einsteinists a fix that makes c the speed limit???

See my post above.

Your post means that there is no post 1906 Einsteinian fix, what u describe is in effect the pre 1906 argument.

One can also argue that the reason is an intimate connection of c with space-time geometry in special relativity. FTL speeds can easily lead to the breaking of causality.

FTL speeds might break causality.
Wikileaks.....Causality is the relationship between causes and effects.[1][2] While causality is also a topic studied from the perspectives of philosophy, from the perspective of physics, it is operationalized so that causes of an event must be in the past light cone of the event and ultimately reducible to fundamental interactions. Similarly, a cause cannot have an effect outside its future light cone.
But what is the Einsteinian cause for c being the speed limit??? Using post 1906 Einsteinian theory.

[crawler]

Causality is a circular argument here.
Causality says that nothing can exceed the speed of c (but might equal c).
My question was how is c a speed limit (in the modern post 1906 dogma)(& in the real world).
So, what is the modern dogma answer??
I have not yet dealt with the real world answer, might later today.

[Aardwolf]

My question was how is c a speed limit (in the modern post 1906 dogma)(& in the real world).

It's not. It's just the local measured speed of EM radiation. Any additional properties are conjecture.

[crawler]

My question was how is c a speed limit (in the modern post 1906 dogma)(& in the real world).

It's not. It's just the local measured speed of EM radiation. Any additional properties are conjecture.

I think that actual measurements of speeds (of em radiation & radio waves & photons & electric fields & electricity) are important. However it is the conjecture that i am interested in. In a sense i am asking what are say 4 explanations of how c is a speed limit,
(1) according to pre 1906 dogma (we know what that is, it is that mass must increase to infinity), &
(2) according to post 1906 dogma (i am not aware of that explanation)(but i think that it cant use any increase in mass), &
(3) according to neo dogma (ie according to the modern version of post 1906 dogma)(i suspect that it is a regurgitation of (1), ie ignoring (2), ie ignoring that Einstein after 1906 did not believe that mass increased with speed), &
(4) according to real world explanation(s) (ie not involving any silly Einsteinian dogma)(but not ruling out other versions of mass increase).

[Solar]

My question was how is c a speed limit (in the modern post 1906 dogma)(& in the real world).

The speed of light is a Physical Constant. Not a limit.

There are many physical constants in science, some of the most widely recognized being the speed of light in vacuum c, the gravitational constant G, the Planck constant h, the electric constant ε0, and the elementary charge e. - Wikipidea

It is listed amongst the other Physical Constants

A Limit:

In mathematics, a limit is the value that a function (or sequence) "approaches" as the input (or index) "approaches" some value.[1] Limits are essential to calculus and mathematical analysis, and are used to define continuity, derivatives, and integrals. - Wikipedia

[crawler]

My question was how is c a speed limit (in the modern post 1906 dogma)(& in the real world).

The speed of light is a Physical Constant. Not a limit.

There are many physical constants in science, some of the most widely recognized being the speed of light in vacuum c, the gravitational constant G, the Planck constant h, the electric constant ε0, and the elementary charge e. - Wikipidea

It is listed amongst the other Physical Constants
A Limit:

In mathematics, a limit is the value that a function (or sequence) "approaches" as the input (or index) "approaches" some value.[1] Limits are essential to calculus and mathematical analysis, and are used to define continuity, derivatives, and integrals. - Wikipedia

I meant why is c the speed limit for a body.
I didnt mean to question how & why c is c.
But seeing that u mentioned it, i consider that c km/s is the speed of a photon in vacuum well away from any matter or any mass of any kind including other photons & also radio waves, & neutrinos etc.
c becomes c' when near mass (eg Shapiro Delay).
c becomes c" when in mass (air water glass)(refraction).
c becomes c'" when both in mass & near mass.

In addition we have problems with c in the near field where it has been measured to be more like 5c km/s (see Gasser, & others)
Or infinite km/s (see Hertz)(probly far field not near field).

In addition we have problems with c in the far field where it has been measured to be c+v & c-v (see Michelson Morley Miller Demjanov Cahill & others).

[Solar]

I meant why is c the speed limit for a body.

Matter, a body, exhibits a quality called “mass” (kg).

According to theory Photons do not have “mass”. They are said to be massless, or massfree.

But seeing that u mentioned it, i consider that c km/s is the speed of a photon in vacuum well away from any matter or any mass of any kind including other photons & also radio waves, & neutrinos etc.
c becomes c' when near mass (eg Shapiro Delay).
c becomes c" when in mass (air water glass)(refraction).
c becomes c'" when both in mass & near mass.

In addition we have problems with c in the near field where it has been measured to be more like 5c km/s (see Gasser, & others)
Or infinite km/s (see Hertz)(probly far field not near field).

In addition we have problems with c in the far field where it has been measured to be c+v & c-v (see Michelson Morley Miller Demjanov Cahill & others).

There are no problems with those experimental things listed. The original premise that "nothing can travel faster than the speed of light in vacuum" contains a contradiction. No one anywhere has shown where this ideal "vacuum" having no properties, no fields, no matter, no energy of any sort, actually exist. All of a sudden a photon, which does have energetic properties is simply made to accelerate within same? What accelerated the photon's emission when this "vacuum" has no properties to do so? How did this photon even arise in a location that has no influences from any medium??

Because “the speed of light in vacuum" is not something that can be demonstrated it is therefore an assumption, a concept, an idea. Here is Forbes article trying to explain that:

The Universe Has A Speed Limit, And It Isn't The Speed Of Light

[Brent72]

Crawler have you seen Alexander Unzicker's work in this area?
Unzicker shows that Einstein had a constant speed of light for 'curved' spacetime but a variable speed of light in 'flat' space.
https://www.youtube.com/watch?v=2NdUcR4unYs
The interesting thing is, if you accept that light speed is a function of the masses, and that in the past the speed of light was faster than the current c, but slowed due to increasing mass in the universe, then this can explain redshift - (i.e that it's not cosmological expansion but just light slowing). [Thanks Paladin17 for first posting that link]. Unzicker also shows that this actually fits the data much better.
Variable light speed is 'Einstein's lost key': https://www.youtube.com/watch?v=o67TNtgPPck
Also variable light speed can explain the appearance of time dilation, which relativitists use to prove their theory. Ron Hatch talked about this at EU 2013 https://www.youtube.com/watch?v=CGZ1GU_HDwY

[crawler]

I meant why is c the speed limit for a body.

Matter, a body, exhibits a quality called “mass” (kg).
According to theory Photons do not have “mass”. They are said to be massless, or massfree.

But seeing that u mentioned it, i consider that c km/s is the speed of a photon in vacuum well away from any matter or any mass of any kind including other photons & also radio waves, & neutrinos etc.
c becomes c' when near mass (eg Shapiro Delay).
c becomes c" when in mass (air water glass)(refraction).
c becomes c'" when both in mass & near mass.

In addition we have problems with c in the near field where it has been measured to be more like 5c km/s (see Gasser, & others)
Or infinite km/s (see Hertz)(probly far field not near field).

In addition we have problems with c in the far field where it has been measured to be c+v & c-v (see Michelson Morley Miller Demjanov Cahill & others).

There are no problems with those experimental things listed. The original premise that "nothing can travel faster than the speed of light in vacuum" contains a contradiction. No one anywhere has shown where this ideal "vacuum" having no properties, no fields, no matter, no energy of any sort, actually exist. All of a sudden a photon, which does have energetic properties is simply made to accelerate within same? What accelerated the photon's emission when this "vacuum" has no properties to do so? How did this photon even arise in a location that has no influences from any medium??

Because “the speed of light in vacuum" is not something that can be demonstrated it is therefore an assumption, a concept, an idea. Here is Forbes article trying to explain that:
The Universe Has A Speed Limit, And It Isn't The Speed Of Light

Nice article. But it is Einsteinian, & assumes a bigbang universe etc. Much of the info is also ok in an infinite eternal aetheric universe.
Most of all it ignores the existence of aether, the fundamental essence. Photons being an annihilation & excitation of the aether.

I agree that an ideal vacuum cant exist. But there must be lots of kinds of ideal vacuum.

Forbes' ideal vacuum (Ethan Siegel) contains nothing (having no properties, no fields, no matter, no energy of any sort.
But there's no such thing, practically, as a perfect vacuum. Even in the deepest abyss of intergalactic space, there are three things you absolutely cannot get rid of.

The WHIM: the warm-hot intergalactic medium. This tenuous, sparse plasma are the leftovers from the cosmic web. While matter clumps into stars, galaxies, and larger groupings, a fraction of that matter remains in the great voids of the Universe. Starlight ionizes it, creating a plasma that may make up about 50% of the total normal matter in the Universe.

The CMB: the cosmic microwave background. This leftover bath of photons originates from the Big Bang, where it was at extremely high energies. Even today, at temperatures just 2.7 degrees above absolute zero, there are over 400 CMB photons per cubic centimeter of space.

The CNB: the cosmic neutrino background. The Big Bang, in addition to photons, creates a bath of neutrinos. Outnumbering protons by perhaps a billion to one, many of these now-slow-moving particles fall into galaxies and clusters, but many remain in intergalactic space as well.
A multiwavelength view of the galactic center shows stars, gas, radiation and black holes, among... [+] other sources. But the light coming from all of these sources, from gamma rays to visible to radio light, can only indicate what our instruments are sensitive enough to detect from 25,000+ light years away.

Any particle traveling through the Universe will encounter particles from the WHIM, neutrinos from the CNB, and photons from the CMB. Even though they're the lowest-energy things, the CMB photons are the most numerous and evenly-distributed particles of all. No matter how you're generated or how much energy you have, it's not really possible to avoid interacting with this 13.8 billion year old radiation.

An Aetherist's ideal vacuum contains no matter (ie no particles).
But depending on context might in addition contain no radiation or fields of any kind (but can contain gravity fields).

Einstein's ideal vacuum contains no matter & no gravity waves (ie no gravity fields)(but i think can contain photons & em fields etc).

[crawler]

Crawler have you seen Alexander Unzicker's work in this area?
Unzicker shows that Einstein had a constant speed of light for 'curved' spacetime but a variable speed of light in 'flat' space.
https://www.youtube.com/watch?v=2NdUcR4unYs
The interesting thing is, if you accept that light speed is a function of the masses, and that in the past the speed of light was faster than the current c, but slowed due to increasing mass in the universe, then this can explain redshift - (i.e that it's not cosmological expansion but just light slowing). [Thanks Paladin17 for first posting that link]. Unzicker also shows that this actually fits the data much better.
Variable light speed is 'Einstein's lost key': https://www.youtube.com/watch?v=o67TNtgPPck
Also variable light speed can explain the appearance of time dilation, which relativitists use to prove their theory. Ron Hatch talked about this at EU 2013 https://www.youtube.com/watch?v=CGZ1GU_HDwY

Thanx for thems links to youtube. I have probly seen all of them, my memory is krapp. I like Unziker & Hatch.

I like the Dicke slowing of light by the nearness of mass redshift idea (or better put the reduced frequency of created photons due to slowing by the nearness of mass in the early days), but it is based on the bigbang. And doesnt have aether.

I prefer Conrad Ranzan's cosmological redshift idea, based on an infinite eternal cellular dynamic aetheric universe.

And i like the Machian idea that gravity (& the SOL)(Dicke) are affected by the mass of the universe. But this needs to be restricted to referring to the mass of the local cosmos. The only mechanical explanation for this is my own idea re gravity force being a reverberation tween cosmic bodies etc whereby the massless aether acts as the agent for the pulses.

All of this supports my earlier posting that we have c & c' & c" & c'".
And the speed limit for a body is thusly c & c' & c" & c'".