Distance to horizon problem
Distance to horizon problem
(OP)
Any help/hint on the following would be appreciated.
Can we see (with naked eyes) a 150 ft tall, 2 ft wide pole from a 40 ft tower separated by 15 miles on a relatively flat terrain? I also wonder if "distance to horizon" approach would be applicable. Please suggest.
Thanks.
Can we see (with naked eyes) a 150 ft tall, 2 ft wide pole from a 40 ft tower separated by 15 miles on a relatively flat terrain? I also wonder if "distance to horizon" approach would be applicable. Please suggest.
Thanks.





RE: Distance to horizon problem
I get that it would be visible, for a separation of up to about 23 miles. As I recall there is curvature of light involved which I did not consider but should be negligible.
I don't believe the "standard" naked eye is that good to see a 2' wide pole 15 miles away though, but maybe under the right light and contrast..
RE: Distance to horizon problem
RE: Distance to horizon problem
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"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: Distance to horizon problem
If you mean detect a difference between the object and its background, then, under the right conditions, yes, you can "see" the tower.
If you mean whether you can tell that it's a 2-ft tower, then the answer is no.
2ft/15mi ~ 5 arcseconds. All stars at night subtend less than 5 arcseconds, and we can "see" them, even at from 20 ly away.
TTFN
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RE: Distance to horizon problem
**********************
"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: Distance to horizon problem
Nonetheless, you can "see" them, i.e., tell the difference between them and their background, which was the question I posed about what is meant by "see." So, if the tower was adequately contrasted with its background, you could "see" it. There would be no detail, nor any indication of actual width, but again, that's not necessarily required to achieve "seeing"
Note that this is fundamentally different that "resolving" 2ft at 15 mi. That would require you to tell the difference between 2ft objects spaced 2ft apart at 15 mi, which is impossible with the naked eye.
As we know, detailed understanding of the requirements spells the difference between success and failure, so the OP needs to define his problem more precisely.
TTFN
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