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Russian military leaders have expressed concern about US plans
for a national missile defense system. Will defense technology be
limited by possibilities for a strategic imbalance? Is this just SDI
all over again?
(1166 previous messages)
- 09:30am Mar 19, 2001 EST (#1167
While I'm typing, I'd like to say that Steve was much interested
in peacemaking. The account above is correct, but also a smoothing
over of phyologically and emotionally significant detail. Discussion
of one of the people involved, who died before Steve, was enough to
make Steve wince with rage, right to the very end of his life. I
liked that particular person very much, and had personal reasons to.
- 09:42am Mar 19, 2001 EST (#1168
Had I been a little luckier, he would have been my father in law.
- 09:54am Mar 19, 2001 EST (#1169
Correction, end of 1166:
"Indeed John Laufer who had initially been one of the most
skeptical individuals about the visual evidence was kind enough, and
of sufficient stature, that he wrote me saying that he had been very
skeptical initially, but the results cited above had convinced him
that what the Stanford group had said about the role of the
ejections from the sublayer was at least largely correct."
. . . . . "partially" - which I typed before, was too weak.
- 10:21am Mar 19, 2001 EST (#1170
6. The Era of CFD (computational fluid dynamics) - - - 1986 -
“The era of CFD in structure studies began when computers became
big enough and fast enough so that direct solutions of the
Navier-Stokes equations (DNS, for “direct numerical solutions”)
could be performed for at least some turbulent flows. …
Steve Kline’s student S.K Robinson, now an
astronaut, made great progress in using CFD. Under Kline’s direct
supervision, as part of his Ph.D. thesis, Robinson produced
calculations associated with stunning pictures of eddies that look
like experimental eddies, for a boundary layer. (Robinson has said
that Steve was mercilessly demanding during this period. I was
working with Steve also at this time, though not as his student,
and I believe him.)
“Robinson used the data from the DNS solution for the plate by
Spalart to sudy the structure of the boundary layer. He showed the
wall layers do contain counter-rotating vortices oriented and tilted
downstream” --- and much other breakthrough detail. “For further
detail, see Robinson (1991) and its continuations in a paper by
Kline and Portela in this volume.”
“While the shift from the Era of Statistics to the Structural Era
involved a paradigm shift in much the way Kuhn suggests, the other
two shifts in era did not. The reasons are different. The shift to
the statistical era was a movement into uncharted territory where
there had been no data and no theory. Hence there were no previous
workers to resist the change. The shift to the CFD era did not
involve a paradigm shift in the view of turbulence. It involved
rather a large increase in the power available for computation.
- 10:27am Mar 19, 2001 EST (#1171
"“When two (or more) groups of scholars create conflicting
solutions for a single problem, then it is likely that each group of
scholars has some of the truth, but not all of it.”
Isn't it always a case? Do you believe it is possible to have ALL
of the truth?
I am not sure how relevant the philosophy of science is to this
forum but it is definetly a very exciting topic.
In my view, the science is an attempt to create an all
encompassing model based on a limited number of
observations taken with the limited precision using
defined methodology, deemed to be constant and true.
The model assumed to be true if it can predict the pattern of those
observations during some (limited) validation period using
the some deemed to be valid observation methodology.
As one can see, there are a too large of the number of
assumptions in any scientific proposition to ever claim to be
absolute true. All we can talk about is some degree of a relative
Moreover, one of the main assumption is the stability of the
model on a time dimension. In other words, we assume that our
observations today using the same methodology would give us the same
result at any point in time in the past or the future.
Phylosophically, I am skeptical we can make such an assumption. In
doing so, we deny the ability to develop and change to the
non-organic "lifeless" matter. Such an assimetrical view does not
look phylosophically correct. What if all the matter evolves, adupts
and changes over time on all material levels from sub-atomic
particles to the galaxies to the universe?
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