Re: sun's distance as lab exercise?

[David Strasburger-fac <David_Strasburger-fac@NOBLES.EDU>]

Thanks, Leigh.

I'm actually happy if my kids end up with values that are on the right
order of magnitude -- I think of this as an exercise that leads into the
standard scale-model-on-football-field demo.  I'm hoping that experience
will be more powerful for the students if they generated the values we use
in setting out the bowlingball sun and peppercorn earth.  I'll try starry
night.

David


___________________________
PHYS-L@lists.nau.edu writes:
> The instant of quadrature of the Moon cannot be determined sufficiently
> accurately to measure the distance ratio. The method was tried, and I
> believe the result was that the Sun is twenty times more distant than
> the Moon, an error of about a factor of twenty. The angle involved is
> about 1/7 of a degree. Determination to an uncertainty of ten percent
> would require determination of the times of quadrature to an accuracy
> of about one hundred seconds.
>
> I have tried similar things with my favorite planetarium emulator,
> Starry Night Pro. If your students want to try, the data you are
> seeking (longitudes of positions with Sun and Moon in the zenith at
> quadrature) can be obtained using this tool. As a practical matter,
> however, it can't be done.
>
> Leigh