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List:       opensuse
Subject:    Re: KDE help from a practical time
From:       "David C. Rankin" <drankinatty () suddenlinkmail ! com>
Date:       2023-12-07 3:36:40
Message-ID: d7cb2748-3ef0-496b-979b-2754f6fbe049 () suddenlinkmail ! com
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On 12/5/23 01:26, Darryl Gregorash wrote:
> I rather doubt one needs that much precision for astronomical calculations, 
> especially when working with an object that
> a) has an angular diameter of approximately 0.5 degrees, and
> b) is an oblate spheroid whose oblateness isn't really known to very much 
> precision.
> I used LHC and LIGO as examples, because those are two examples where high 
> precision is really needed. In the case of LIGO, for example, the delay is 
> very, very small between receiving a true wave signal at each detector 
> (gravitational waves travel at the speed of light). With the LHC, the time 
> windows are even more critical, given a) the huge numbers of decay products 
> that happen between the original collision and detection of the final decay 
> products, and b) the relatively small sizes of the detectors.
> Besides, that equation you give looks to me like a perturbation expansion, 
> unlikely anything close to single precision, and only taken out to 3 terms.

All depends on the number of coordinate system transformations involved before 
and after where precision bleed hurts. The transendentals and angular 
conversions (especially for angles near 0 and Pi).

LHC and LIGO are both good examples. Monitoring for 10 billion year old 
gravity-waves is serious business :)

-- 
David C. Rankin, J.D.,P.E.
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