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Re: (meteorobs) Angular Speed Equations
me>>If you have 2 or more meteors that intersects to give one
>a reason to think about a possible radiant position, the
>position area becomes obvious.<<
Lew>> Again as you yourself pointed out, any meteor
plot has an inherent error associated with it. The point
we've been trying to help you understand is that, due to
this error, a series of four or five meteor plots really
has no reliable "point of intersection" - even if you're
lucky enough to have five plots with very diverse angles
to the radiant, relative to one another! (And of course,
in practice, at least two or 3 of these will actually be
near one another in the sky, and so not be very diverse.)<<
Yes just about any meteor plot will have an inherent error associated with
it. That's the nature of gathering data with the eyeball. Every aspect of
gathering data with the eyeball has an inherent error....whether it's
alignment errors, or judging a meteors path length, or duration or radiant
distance. A series of 4 or 5 intersecting meteor plots gives one a very good
idea where an unknown radiant might turn up at. Just about as accurate as can
be expected from any visual observations. They wouldn't be any less accurate
trying to determine where a radiant might be, than trying to judge it by
angular velocity estimations, path length and radiant distance alone. If you
can't come close with meteor intersections, you won't be doing any better
with angular velocity estimations/path length, radiant distance estimations
either. You still gonna have to rely on alignment to determine just where
along that meteor path to say the radiant might be. If you are off with just
the intersects, you will be off the same amount when you incorporate angular
velocity guestimates. In essence, meteor alignment is the key factor in
locating unknown radiants. Without accuracy in this aspect, neither method is
gonna be worth a hoot. To get any better, you will have to elevate to more
reliable means....that is with additional equipment. To find new radiant
positions, you first note the intersects. From there you note path lengths
and distances from radiant to weed out unrelated meteors. Then note their
speed relationships. There is nothing magical that angular velocities is
gonna do for you that can't be done with just noting a speed scale, path
lengths, meteor intersects and meteor distances from the intersects.
lew>>As a result, Malcolm and Bob have suggested we plotters
find ways of reducing that inherent "uncertainty region"
in the radiants of as-yet-unconfirmed new minor showers.
And one of the best ways to reduce the error is by trying
to make a precise measurement of angular speed: obviously,
like with the plot itself, any visual estimate of speed
is bound to have errors inherent in it.<<
The best way to reduce this error to find as-yet-unconfirmed new minor
showers is to increase the accuracy of alignments. Without this, nothing is
gained in reducing any "uncertainty region". The "uncertainty region" will
end up being the same whether you use a speed scale or play around with
angular velocity estimates. Visual observers are not making "precise
measurements" of angular speed. These are estimates or even guestimates if
you will. If there were someway for a visual observer to come up with super,
ultra precise measurements of angular speed only, the error will be the same
if alignments aren't done any better. And it's the alignments and resulting
intersects that denotes the area of a radiant.
lew>>HOWEVER (here's
where you need to start reading over again), the belief
is that these approximate angular velocities, along with
an approximate set of intersections, can produce a MORE
PRECISE possible radiant area - <<
You are kidding aren't you? :o) There wouldn't even be an increase in
accuracy of a possible new radiant area if god gave you the exact angular
velocites. Without any gain in accuracy with the plotted alignments, you
haven't gained anything. The intersects will be just as inaccurate with exact
angular velocites as without.
lew>> But I offer
George the same advice I've given many newcomers in the
past when something is unclear: read it over, think on
it for a few days, come up with COGENT questions, and
then get back to the list! <<
I have read it all many times lew. It's not unclear to me at all...have a
very good grasp and concept of what's being discussed. It's second nature to
me. Perhaps some day it will occur to you what I'm saying and when that
happens, we should all see a bright light bulb turn on.
lew>>Debate by email barrage will
not convince anyone else on this list of ANYTHING: but
thoughtful discussion and well-designed questions may!<<
It won't convince anyone unless they read it all. I don't know how to make it
any more simpler for you to grasp. I think I have been participating in a
thoughtful discussion with well designed questions. You think if I increase
the size of my type it would help any? :o)
GeoZay
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