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DaveC426913

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Thinking last night about what I should expect see of the Toronto skyline, which is 40 miles across the lake from me.

Starting with an ideal scenario (nape-of-shore to nape-of-shore), a chord calculator tells me that for r=3900 mi. d=40 mi. the chord height will be 270 ft.

I was surprised at that height, and doubted my calculations. A 270 foot mountain in the middle of the lake is a lot! But I soon realized that it's not really a lot over 40 miles. It's rise-over-run of only 1:780.

At first I assumed everything below that 270 foot mountain would be obscured, so I would only be able to see buildings from the 28th floor and up (assuming they are at the waterline). But upon reflection, I think I won't be able to see anything below

Confounding Factors:

Are my assumptions and calculations correct?

(Apologies for my wanton mixing of SI and metric)

Starting with an ideal scenario (nape-of-shore to nape-of-shore), a chord calculator tells me that for r=3900 mi. d=40 mi. the chord height will be 270 ft.

I was surprised at that height, and doubted my calculations. A 270 foot mountain in the middle of the lake is a lot! But I soon realized that it's not really a lot over 40 miles. It's rise-over-run of only 1:780.

At first I assumed everything below that 270 foot mountain would be obscured, so I would only be able to see buildings from the 28th floor and up (assuming they are at the waterline). But upon reflection, I think I won't be able to see anything below

*double*that, or 540 feet.Confounding Factors:

- I don't think my height above the water will make a difference if it's small enough. I mean, if my sightline is 10 feet above the waterline, that'll mean I can see down to 530 feet instead of 540 feet, right?

- I also have to remember that the visible buildings are many metres above the waterline, so I can't just count building stories to estimate altitude.
- And I'll have to time the observations right, when atmospheric refraction is at a minimum.

Are my assumptions and calculations correct?

(Apologies for my wanton mixing of SI and metric)

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