[geocentrism] Re: The resolution of Mars

You find out that you are measuring two different things
- at least in this case.

   Regards,

      Regner

Sorry, I kow this is off subject, but I appreciate the free lesson on 
astronomy. 

Though this is a simplification, am I'm gettting it correct. On the one hand 
you are measuring intensity, which has nothing to do with resolution of size, 
but it can by parallax give you distance.

And then on the other hand you can by use of known magnification with a 
telescope resolve the size of only a few of the closest stars... 

Then how come we are told the size of so many stars.  Is it only a guess based 
upon brightness (spectrum analysis etc.) and distance? 

 How can we with certainty distinguish between a smaller intense star from a 
less intense larger star or visa versa.  Are we not presuming stars to have 
certain characteristics based only on observation of our sun and perhaps some 
of the closer stars?

Philip.  
for the interested, from http://www.stargazing.net/David/constel/magnitude.html
"Brightness of stars are assigned a number starting with the brightest star 
starting at about -1 magnitude. Dimmer stars are zero or positive numbers. The 
larger the number means the dimmer the star is. For example, a star -1 
magnitude is brighter than a star 0 magnitude. A star 0 magnitude is brighter 
than a star 1 magnitude. A star 1 magnitude is brighter than a star 2 
magnitude. A star 4 magnitude is brighter than a star 5 magnitude. Magnitude 
sequence for stars starting with the brightest is -1, 0, 1, 2, 3, 4, 5, 6, 7, 
8, 9, 10 magnitude, ... etc. 

The decimal point is not used when star magnitudes are used on a star map. The 
decimal point could be confused for a star on the map. At the top of this page 
is the constellation Ursa Minor with star magnitudes for some of its stars. For 
example, magnitude 31 on the star map mean 3.1 and magnitude 55 on the star map 
mean 5.5. 

Historicaly the magnitude system started with Hipparcus and Ptolemy .......etc.

  ----- Original Message ----- 
  From: Regner Trampedach 
  To: geocentrism@xxxxxxxxxxxxx 
  Sent: Tuesday, November 27, 2007 8:26 PM
  Subject: [geocentrism] Re: The resolution of Mars


  Quoting Jack Lewis <jack.lewis@xxxxxxxxxxxx>:

  > Dear Regner,
  > The point I was making, or rather Neville was, is that for its distance and 
  > size it should be invisible.
  >
  Exactly - and that was the point I was answering. I told you:
  * It is still bright enough to be visible
  * But it is too small to be resolved so you see it as a point,
    as opposed to an extended object, like a planetary disk.
  We see the stars - they have far smaller angular diameters than
  Mars - I hope even GC folks will agree to that.
  The stars are unresolved.
  No matter how large a conventional telescope you use, you will
  still only see a point of light - not a round star like our Sun.
  With interferometers you can actually see the size of a few of
  the closest stars, but that is irrelevant for this point.

  You need to distinguish between unresolved and invisible.
  Unresolved means that you cannot distinguish it from a point,
  but you can still see it if it is bright enough.

  > So what do you do when you measure something in 
  > one way and the measure it in another way and get completely different 
  > answers?
  > 
  > Jack
  >
  You find out that you are measuring two different things
  - at least in this case.

     Regards,

        Regner

  > Jack
  > 
  > 
  > ----- Original Message ----- 
  > From: "Regner Trampedach" <art@xxxxxxxxxx>
  > To: <geocentrism@xxxxxxxxxxxxx>
  > Sent: Tuesday, November 27, 2007 5:10 AM
  > Subject: [geocentrism] Re: The resolution of Mars
  > 
  > 
  > > That we can't resolve something does NOT mean that it is invisible.
  > > It just means that you can't distinguish it from a point. Grab your
  > > binoculars and you can resolve Mars into planetary disk.
  > >  You can't resolve the lights of an airplane high in the sky, but you
  > > sure can still see them.
  > >  As far as Mars goes, you can directly measure the distance to Mars
  > > using parallax - not the yearly one around the Earth's orbit - which I
  > > know you all dispute - but an instantaneous one from opposite (or nearly
  > > so) sides of Earth. Add the angular diameter observed with a telescope
  > > at that same time, and you can also find it's absolute diameter. Violá!
  > >
  > >   Regards,
  > >
  > >      Regner
  > 
  > 





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