Re: In an RDBMS, what does "Data" mean?

In message <I6OdnWVb0NNbWTvdRVn-uw_at_comcast.com>, Laconic2 <laconic2_at_comcast.net> writes
>Try as I might, I cannot find confirmation of your extraordinary assertion
>that the relativisitc precession of mercury was observable in Tycho's data.
>I don't think you are right about this.
>
>Keep in mind that the vast majority of mercury's precession is explainable,
>in classical Newtonian mechanics, by the gravitational attraction of the
>other planets.
>
>In the timelines I've seen, the observation of 35 arcseconds per century of
>excess precession of Mercury was attributed to an observation in 1845 by
>Leverrier. It was further corrected to an excess of 43 arcseconds per
>century by Newcomb in 1882.

I did a "google" on "mercury orbit newton relativity", and it gave me a load of good pages. About the first one I looked at (the third or so it found) gave me rather bigger figures than yours for precession (although it did have a few problems...)

>Before Einstein, the excess precession of Mercury was attributed to a
>hitherto unknown (and, it turns out nonexistent) planet inside the orbit of
>mercury, to which they gave the name "Vulcan". (Live long and prosper).

And apparently half the excess precession found by Newton was due to relativity ...
>
>But the descriptions of the amount of time for which you need observations
>of Mercury to obtain these findings are very long. So long that I find it
>doubtful that Tycho could have observed for long enough for his data to
>detect the Einsteinian precession.

How long? Don't forget. Tycho STARTED these observations in about 1550. Newton was around about 1750. So he actually had about 200 years worth of data to play with.
>
>As far as Newton refining and cross checking his work, and seeking to verify
>or falsify it down to the last epsilon (so to speak), I find that very easy
>to believe. In fact, his own assessment of his work is that he felt like a
>little child, playing with the shells on the seashore, while the vast ocean
>of truth lay undiscovered before him. And Einstein, when asked to comment
>on Newton's work, said that his own work would have been impossible without
>Newton's earlier work.
>
>Those people in this forum who seem to have every human gift except
>humility might do well to learn from such people as Newton and Einstein.
>

And modern man would do well to learn humility from the ancients. 1 arcsecond is easily detected today, I would think. And it wouldn't surprise me if Newton had access to some pretty accurate instruments too - why shouldn't he be able to resolve with that sort of accuracy too? With two centuries of data, that makes well over an arcminute due to relativity alone. We know he could detect that sort of accuracy, because he was trying to explain it!

(The website I looked at said the precession was more like 540 arcseconds a year, but it also said there were 360 arcseconds in a degree, so I think it has mislaid a few powers of ten somewhere :-)

Cheers,
Wol

-- 
Anthony W. Youngman - wol at thewolery dot demon dot co dot uk
HEX wondered how much he should tell the Wizards. He felt it would not be a
good idea to burden them with too much input. Hex always thought of his reports
as Lies-to-People.
The Science of Discworld : (c) Terry Pratchett 1999