Re: The first postulate is a truism.

On 2025-06-23 21:25:18 +0000, LaurenceClarkCrossen said:

On Sun, 22 Jun 2025 9:43:49 +0000, Mikko wrote:
 

On 2025-06-21 21:14:11 +0000, LaurenceClarkCrossen said:
 

On Sat, 21 Jun 2025 10:19:43 +0000, Mikko wrote:
 

On 2025-06-20 18:55:34 +0000, LaurenceClarkCrossen said:
 

On Fri, 20 Jun 2025 9:06:49 +0000, Mikko wrote:
 

On 2025-06-19 17:37:29 +0000, LaurenceClarkCrossen said:
 

Perplexity:
 "The First Postulate of Special Relativity
 Statement of the First Postulate
 The first postulate of special relativity, also known as the principle
of relativity, states:
 The laws of physics are the same in all inertial frames of
reference."
  "truism
/ˈtrˌizƏm/  n. a statement that is obviously true and says nothing new
or interesting. —truistic/trˈistik/ adj." -Oxford American.

 The first postulate is not a truism. It is possible to imagine a world
where it is not true and to believe that we actually live in a such
world.

 

Your reply does not explain how it is not obviously true and nothing new
that wasn't already known long before Einstein.

 I did explain. And what I said was indeed known long before Einstein.
 If the first postulate were a truism nobody would ever have believed
otherwise. But ancinet literature shows that the opposite belief was
common.

 

So, Einstein added nothing new. How does that provide a basis for his
new theory? That he accepted the consensus view since Newton?

 No earlier theory had both the first and the second postulate as
postulates.

I was obviously talking about the first postulate. It only accepts the
consensus view since Newton. It adds nothing new.

In 1905 the consensus view was not that it applies to all phenomena.
In particular the question was open about electromagnetism, which
was not known at Newton's time.
Newton himself did not believe that the first postulate is fundamentally
true. Instead he believed that there is one and only one absolutely
stationary frame. But at the time there were no known law that was known
to be true in that frame only and consequently there was no way to
identify that frame.
--
Mikko