Just wondering
- dave_lillis
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16 years 9 months ago #60996
by dave_lillis
Dave L. on facebook , See my images in flickr
Chairman. Shannonside Astronomy Club (Limerick)
Carrying around my 20" obsession is going to kill me,
but what a way to go.
+ 12"LX200, MK67, Meade2045, 4"refractor
Replied by dave_lillis on topic Re: Just wondering
Here is a trick for you Seanie.
2 circles of diameter 6 and 8 have the same proportion in surface areas as do a 6 and 8 inch squares.
Using AxA
6"sqaure = 36
8"sqaure = 64
Using pi(r)squared
6"circle = 113.1
8"circle = 201
64/36 =1.78
201/113=1.78
Its a very nifty trick for comparing scope light gathering powers.
2 circles of diameter 6 and 8 have the same proportion in surface areas as do a 6 and 8 inch squares.
Using AxA
6"sqaure = 36
8"sqaure = 64
Using pi(r)squared
6"circle = 113.1
8"circle = 201
64/36 =1.78
201/113=1.78
Its a very nifty trick for comparing scope light gathering powers.
Dave L. on facebook , See my images in flickr
Chairman. Shannonside Astronomy Club (Limerick)
Carrying around my 20" obsession is going to kill me,
but what a way to go.
+ 12"LX200, MK67, Meade2045, 4"refractor
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- Seanie_Morris
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16 years 9 months ago #61039
by Seanie_Morris
Midlands Astronomy Club.
Radio Presenter (Midlands 103), Space Enthusiast, Astronomy Outreach Co-ordinator.
Former IFAS Chairperson and Secretary.
Replied by Seanie_Morris on topic Re: Just wondering
Ah, ok Dave, so I might stand corrected! 
Midlands Astronomy Club.
Radio Presenter (Midlands 103), Space Enthusiast, Astronomy Outreach Co-ordinator.
Former IFAS Chairperson and Secretary.
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- Seanie_Morris
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- pj30something
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