🚀 go-pugleaf

John Kennaugh wrote:
> GSS wrote:
>> On Jun 12, 6:31 pm, jem <x...@xxx.xxx> wrote:
>>> John Kennaugh wrote:
>> .........
>>>> How a mathematical abstraction (a FoR) can posses the same physical
>>>> properties as the aether and force light to propagate every which 
>>>> way at
>>>> c when it defines physical space which those same relativists are
>>>> adamant contains nothing physical - no aether - is absurd.
>>>
>>>> I have Tom Roberts in effect saying "never mind the physical, jump in
>>>> the maths is luverly." The maths works provided you have complete
>>>> freedom to redefine anything which prevents it from working and you
>>>> accept the modern view that physical interpretation is not only
>>>> unnecessary but a singularly bad idea.
>>>
>>> The math of *every* physical theory has a direct link to measurement,
>>> and that link /is/ the "physical interpretation".
>>>
>> Do you consider GR to be a physical theory?
>> If so then where is the direct link of *space curvature* to
>> measurement?

The link mentioned above is between real-world measurements (e.g. 
ruler and clock measurements) and the variables (e.g. x,y,z,t) of 
physical theories (e.g. GR).

>> In reality you can neither physically measure the space curvature nor
>> describe a technical procedure for measurement of space curvature even
>> in principle. You cannot even define the space curvature in physical
>> terms (other than the usual mathematical definition in GR).

In reality, you don't know what you're talking about.

Learn before pontificating.

>>
>> I hope you can atleast mentally visualize the space curvature! Can
>> you??
>>>> If it doesn't work on a physical level - it doesn't work. If there is
>>>> nothing to cause a physical effect then there cannot be a physical
>>>> effect. Nothing happens because the maths says so. Things happen 
>>>> because
>>>> of real physical processes and it is a legitimate aim of physics to try
>>>> and understand nature not merely to mathematically model it.
>>>
>>> What do you think cause-and-effect relationships /are/, Kennaugh,
>>> other than logical connections between certain behavior of Nature and
>>> other behavior?  And what do you think physical theories /are/, other
>>> than devices for inferring certain behavior of Nature from other
>>> behavior*?
>>>
>> Causality denotes a necessary relationship between one event (called
>> cause) and another event (called effect) which is the direct
>> consequence (result) of the first. If a certain sequence of events is
>> not causally connected, that set of events will be referred as random
>> events.
> 
> Surely random events are ones where the cause is far to complex to 
> analyse or predict rather than one not having a cause.
> 
>> If a sequence of events is causally connected, we may
>> attribute such causal connection between events to certain physical
>> law of nature. If appropriate logical explanation is available for the
>> causal connection between events then such  causal connection plus the
>> appropriate logical explanation is called a physical theory of the
>> associated phenomenon.
> 
> If only! Modern physics allows itself liberties whereby a theory can be 
> accepted with totally absurd causality. Take SR and Doppler shift.
> Suppose you are stationary w.r.t a source 1 light year away. According 
> to SR light travelling w.r.t. you travels at c having separated from the 
> source at a speed of separation c. If you now change your speed so that 
> you are travelling away from the source at v the frequency of the light 
> you observe will be lower due to Doppler shift but according to SR the 
> light still travels at c w.r.t you. If c hasn't changed and the 
> frequency has, then the wavelength must have changed. What the maths is 
> saying is that in your new frame of reference the wavelength has changed 
> because the light is now separating from the source at c+v generating 
> longer wavelengths than previous. The problem with this is that your 
> change of speed has apparently caused a change in what is happening at 
> the source 1 light year away with no possible causal mechanism. What is 
> even more absurd is that the change has to be backdated to 1 light year
> ago as there is no 1 year delay in the frequency changing. When I point 
> this out to a relativist I am told I am being silly and that one has 
> changed from a FoR where the light separates from the source at c - and 
> always did - to one where it separates from the source at c+v - and 
> always did. That is simply a description of the mathematics not of what 
> is physically happening. Physically one has to assume that when you
> change speed you change from a universe where light separates from the
> source at c to a parallel universe where it separates from the source at
> c+v and always has done.
> 
> Physical interpretation of SR is not allowed. Relativity is a principle
> theory (a posh name for a mathematical model) and as such makes no
> attempt to address physical questions. The fact is that a FoR is a 
> mathematical abstraction which cannot impose physical restrictions on 
> light photons. The problem is that the physical space which the FoR maps 
> out is claimed not to contain anything which can possibly impose 
> physical restrictions on light photons either.
> 
> The only causal mechanisms that I am aware of is my parallel universe 
> explanation and that put forward by Lorentz involving Lorenz's aether.