From: John Jones on
Pentcho Valev wrote:
> W. H. Newton-Smith, THE RATIONALITY OF SCIENCE, Routledge, London,
> 1981, p. 14:
> "...all physical theories in the past have had their heyday and have
> eventually been rejected as false. Indeed, there is inductive support
> for a pessimistic induction: any theory will be discovered to be false
> within, say 200 years of being propounded. (...) Indeed the evidence
> might even be held to support the conclusion that no theory that will
> ever be discovered by the human race is strictly speaking true. (...)
> The rationalist (who is a realist) is likely to respond by positing an
> interim goal for the scientific enterprise. This is the goal of
> getting nearer the truth. In this case the inductive argument outlined
> above is accepted but its sting is removed. For accepting that
> argument is compatible with maintaining that CURRENT THEORIES, while
> strictly speaking false, ARE GETTING NEARER THE TRUTH."
>
> The pessimistic induction separately introduced by Putnam and Laudan
> is popular among philosophers of science but it is incompatible with
> deductivism. Consider Einstein's 1905 light postulate:
>
> http://www.fourmilab.ch/etexts/einstein/specrel/www/ "...light is
> always propagated in empty space with a definite velocity c which is
> independent of the state of motion of the emitting body."
>
> By a theory I shall mean the deductive closure of the postulate, that
> is, the set of all its consequences deduced validly and in the absence
> of false or absurd auxiliary hypotheses. If the light postulate is
> true, then all its consequences are true, and IN THIS SENSE the theory
> is absolutely true.
>
> If Einstein's 1905 light postulate is false, then its antithesis, the
> equation c'=c+v given by Newton's emission theory of light, is true.
> This can easily be seen on close inspection of the Michelson-Morley
> experiment:
>
> http://philsci-archive.pitt.edu/archive/00001743/02/Norton.pdf
> John Norton: "Einstein regarded the Michelson-Morley experiment as
> evidence for the principle of relativity, whereas later writers almost
> universally use it as support for the light postulate of special
> relativity......THE MICHELSON-MORLEY EXPERIMENT IS FULLY COMPATIBLE
> WITH AN EMISSION THEORY OF LIGHT THAT CONTRADICTS THE LIGHT
> POSTULATE."
>
> http://books.google.com/books?id=JokgnS1JtmMC
> "Relativity and Its Roots" By Banesh Hoffmann
> p.92: "Moreover, if light consists of particles, as Einstein had
> suggested in his paper submitted just thirteen weeks before this one,
> the second principle seems absurd: A stone thrown from a speeding
> train can do far more damage than one thrown from a train at rest; the
> speed of the particle is not independent of the motion of the object
> emitting it. And if we take light to consist of particles and assume
> that these particles obey Newton's laws, they will conform to
> Newtonian relativity and thus automatically account for the null
> result of the Michelson-Morley experiment without recourse to
> contracting lengths, local time, or Lorentz transformations. Yet, as
> we have seen, Einstein resisted the temptation to account for the null
> result in terms of particles of light and simple, familiar Newtonian
> ideas, and introduced as his second postulate something that was more
> or less obvious when thought of in terms of waves in an ether."
>
> Therefore the respective theory (the set of all consequences of the
> antithesis, c'=c+v, deduced validly and in the absence of false or
> absurd auxiliary hypotheses) is absolutely true in the sense that all
> its conclusions are true.
>
> Clearly if "theory" is properly defined the pessimistic induction is
> unjustified. The transition from Newtonian to relativistic mechanics
> was either a transition from absolutely false to absolutely true or a
> transition from absolutely true to absolutely false.
>
> Pentcho Valev
> pvalev(a)yahoo.com
From: glird on
On Mar 27, 2:32 pm, John Jones <jonescard...(a)btinternet.com> wrote:
> Pentcho Valev wrote:
>
>> A stone thrown from a speeding train can do far more damage
>> than one thrown from a train at rest; the speed of the particle is not
>> independent of the motion of the object emitting it.

Since JJ never adds his own 2 cents worth to someone else's words,
i will do it for him:
Because the speed of a particle is not independent of the motion of
the object viewing it, the amount of damage a stone thrown from a
speeding train can do depends on the motion of the object it hits.

glird

From: glird on

Pentcho Valev wrote:
> Clearly if "theory" is properly defined the pessimistic induction
is
> unjustified. The transition from Newtonian to relativistic
mechanics
> was either a transition from absolutely false to absolutely true or
a
> transition from absolutely true to absolutely false.

No matter how you define "theory", the ensuing conclusion is false.

glird