Tom Roberts wrote on Sun, 04 May 2008 10:10:36 -0500:
Juan R. González-Ãlvarez wrote:
Almost all relativists invoke the term *causality* (meaning causation)
to select retarded potentials as physical (they also use this term)
solutions to differential equations.
The choice of
retarded vs advanced potentials is boundary conditions, not "causality",
Either you are not reading or just lying.
It is well-known that textbooks and papers *often* invoke *causality* to
select the retarded potentials:
http://adsabs.harvard.edu/abs/1992AmJPh..60..465A
(\blockquote
The use of retarded potentials in solving the wave equation is usually
justified on physical grounds or else by an appeal to *causality*.
)
Emphasis mine.
Moreover, in some sense, it is wrong to speak about "boundary conditions"
for that case.
** quantum field theory most definitely has what you call "creation
ex nihlo" and "demise ad nihil".
Surely it does not, Tom.
Particle pairs pop in and out of existence spontaneously. The quantum
vacuum clearly does what he calls "creation ex nihlo" and "demise ad
nihil".
But you are making a beginner mistake because a quantum vacuum is not
empty and Tom van Flandern's "creation ex nihlo" refers to creation out
from nothing, or like Tom van Flandern would probably say: "empty space".
The quantum vacuum of quantum field theory is other thing carrying energy
momenta, correlations, fluctuations, and populated with virtual particles:
http://en.wikipedia.org/wiki/Vacuum_state
(\blockquote
According to present-day understanding of what is called the vacuum
state or the quantum vacuum, it is "by no means a simple empty
space"[1], and again: "it is a mistake to think of any physical vacuum
as some absolutely empty void."[2]
)
A small problem is you have not the exclusive of the definition of
science, even if you believe you have one.
Making up "principles" like Van Flandern does has not been part of ANY
definition of science, since the middle ages.
That is your belief Tom, just that. Like or not like it, science is that
is published in textbooks, journals and discussed at conferences.
--
http://canonicalscience.org/en/misce...guidelines.txt