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Re^3: 3D test data that exhibits clustering?

by danb (Friar)
on Jun 08, 2011 at 20:28 UTC ( [id://908775]=note: print w/replies, xml ) Need Help??


in reply to Re^2: 3D test data that exhibits clustering?
in thread 3D test data that exhibits clustering?

Plenty of star databases include distance estimates. They're based on trigonometric parallax, absolute-brightness phenomenon, redshift, etc.

Stellarium wouldn't be so much fun without it.

--Daniel

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Re^4: 3D test data that exhibits clustering?
by BrowserUk (Patriarch) on Jun 08, 2011 at 21:12 UTC

    Not so for the one salva pointed at.

    But, in any case, given a sphere of ~250 light years radius, and 600,000 (or even 2.4 million) points, how much clustering would you expect to find?

    On average, that comes out to one star(or visible entity) in every 1e40 cubic kilometers of space. And that assumes that all 2.4m objects in the DB are visible to the naked eye which I doubt.

    Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
    "Science is about questioning the status quo. Questioning authority".
    In the absence of evidence, opinion is indistinguishable from prejudice.
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