Re: Relationship between magnitude and distance

My intuition and my reasoning minds cannot agree with this. Imagine the galaxy
as a series of sheets, the sheets perpendicular to the plane of the galaxy and
to our line of sight. For simplification purposes imagine each *** contains
the same density of stars distributed randomly, and that all of them are
represented by dots of more or less the same size. Certainly this is close to
how ellipticals are organized, and the arms of spirals only means that some
sheets have less stars than others.

Now imagine looking at the galaxy edge-on. As you look through the various
sheets, it becomes more and more probable that a star will block your view of
what is behind it. So as you look deeper and deeper into the galaxy edge-on,
pretty soon you can't see anything deeper because all the stars on those sheets
cover the entire view.

I agree that you get higher surface brightness with face-ons than edge-ons, in
general, but this is mitigated by the fact that you see more stars in the
face-ons, because there is less opportunity for front stars to block those
behind them.

I believe the brightest galaxies tend to be tilted to our line of sight about 45
degrees or so, maximizing the crowding of stars in our line of sight without a
lot of blocking of stars behind other stars.

--- Dave
--
----------------------------------------------------------------------
Pinprick holes in a colorless sky
Let inspired figures of light pass by
The Mighty Light of ten thousand suns
Challenges infinity, and is soon gone

david.nakamoto@xxxxxxxxxxx


"Bill Tschumy" <bill@xxxxxxxxxxxxxxxxxxx> wrote in message
news:dCrle.1351$4N2.590@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> On Thu, 26 May 2005 14:17:58 -0500, David Nakamoto wrote
> (in article <Ghple.9115$GN3.4027@trnddc04>):
>
>> And it's the opposite with edge-ons. You're getting LESS starlight because
>> one
>> star blocks the light from another. You can't see stars behind other stars.
>> And don't trout out the argument that they're just made of plasma and gas.
>> Aside from the fact that plasma can absorb light just as well as solid matter
>
>> under the right conditions, try looking through a cloud sometime.
>>
>> --- Dave
>>
>
> Dave,
>
> I'm not sure you are right about stars blocking other stars. Except for the
> case of close binaries, the average distance between stars is vast compared
> to the stars' sizes. Imagine a tennis ball in Dallas, one in Miami, and
> another up in Seattle. This is the correct scale. So even if you had
> hundreds of thousands of stars in a "core sample" through a galaxy, I
> strongly doubt a significant number would eclipse each other.
>


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