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kynov t1_j1v79df wrote

Reply to comment by Horknut1 in The top of the Boston skyline is just barely visible from Cape Cod by TuggieBoi420

This doesn't seem right. The distance from the Prudential to Long Point would be 51 miles. This would obscure 1,481 feet of height (assuming the person is about 10 feet of above the water on the boat). The Prudential is only 750 feet to the roof (920 to the top of the antenna). Looking at the pic, it looks like about 1/5th of the building is visible so we can estimate that only 150 feet is visible and 600 feet obscured. This means that the photo would have to have been taken at a distance of around 33-35 miles depending on how high above the water they are. 10 feet for a small fishing boat. 15-20 feet for a large one.

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Horknut1 t1_j1vagxq wrote

I think you're missing some modifiers to your calculations. First, he said he's on a boat (likely "doing flips and shit"), so, depending on the size of the whale watching boat, he could be 20/30 feet off the surface of the water.

Also, isn't there a refractory situation with looking to the horizon? I thought I read under the right conditions, even at sea level, you could see buildings 50 miles off.

I mean, do you think this guy is lying?

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ahecht t1_j1vfwkt wrote

To see any of the Pru (excluding the antenna) from 51 miles, ignoring refractory stuff, you'd need to be 200ft up. That said, refraction can do some pretty weird things, Famously, when you get the temperature inversions just right, you can see Toronto from NY State.

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b1ack1323 t1_j1vgwme wrote

Does changing tides have any effect on that?

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ahecht t1_j1vhlme wrote

If you're on a boat, at low tide you'd be able to see 10 more feet of a building in Boston than you can at high tide. If you're on the shore it might be more like 20 feet. In any case, it's a pretty insignificant effect.

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sir_mrej t1_j1w2gwz wrote

> he's on a boat (likely "doing flips and shit")

This is one of the best sly references I've seen

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_Lane_ t1_j1x42uh wrote

Huh. I was thinking he was enjoy carnal knowledge with a mermaid, but yeah, could also be doing flips and shit, too.

(For real: I cannot hear anyone say they are / were on a boat without that song playing. It has both ruined actually being on boats while at the same time it made talking about being on boats awesome.)

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Horknut1 t1_j1vb5ag wrote

https://www.reddit.com/r/boston/comments/1qcj5j/boston_skyline_as_seen_from_the_provincetown/

Interesting related thread, because this picture is from somewhere near 250 feet above ground level, at the top of the Pilgrim Monument.

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CommonNotCommons t1_j1vtu9r wrote

This sent me down a rabbit hole. There are in fact many pictures on this sub over the years of Boston’s skyline from Provincetown. My guess is it has to do with light refraction, because I no longer doubt this view does exist.

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cwmma t1_j1vgfrc wrote

The atmosphere refracts light (curves it downward) so you can see things farther then geometry/trig implies

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BasilExposition75 t1_j1vjnlp wrote

Light can bend in the air depending upon atmospheric conditions. This is why people see mirages.

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richie_cunningham212 t1_j1vbi9l wrote

Yeah, I mean, you did all the work here but also just from my straight simpleton opinion it doesn't seem right. I've never heard that you could see the city from the Cape in all my years around both areas.

Plus something looks funky with the building on the far right. Like its transparency gradient is bleeding into the water appearing like it's edited.

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CommonNotCommons t1_j1vty35 wrote

Oh well, as long as you’ve never heard it.

Also that’s image compression.

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b1ack1323 t1_j1vhgk0 wrote

750 from ground. 775 from sea level. Not that it matters much.

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b1ack1323 t1_j1vja7l wrote

You might have a error unless I have an error:
KcurveEffect * (distance) + elevation = height visible in line of sight at a given distance
1.22 * (82 km) + 3m = 103.04m
100.04m + 3m = 103.04m (338.05 feet)

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