Looking at this picture, the water appears to rise as it gets closer to the ship.  To me it looks as if the boat is just on the other side of the crest of a wave ... which would explain why the bottom part of the ship is not visible.  

If this were a photo from someone trying to deceive you, perhaps they would pick a shot with the crest of a wave in the way. But this is a photo taken by a submarine while attempting to record a GOOD IMAGE of a target ship. They wanted to get the most exposure of the target as possible, and if there were any rogue waves about they would have taken the shot while the target ship was on TOP of the crest with a trough in between the target and the periscope.
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Nobody is trying to fool you, and it's silly to presume you're being lied to. There are hundreds of movies showing periscope images, taken in calm seas, with no erratic waves making things unusual for cherry-picking.
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From the top edge of the water that's in front of the ship it's about 500 to 1000 feet back to the ship.
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What we see is the "hump" in the water's curvature.
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Look closely at the target ship. It has the appearance of a cardboard image.
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That's because telephotos do that to distant objects, which you would know if you had any experience with them.
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The moon appears to be flat as a pancake even with binoculars.
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People walking around at great distance appear to be paper dolls -- FLAT images, but they're MOVING!
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Why, also, is more of the ship's bow visible than the middle and stern?  There appears to be a curvature of the water up towards the middle of the vessel.  Perhaps the water is being displaced upwards further back as the bow of the ship is cutting through the water?  See my point?  If the bottom of the vessel were being hidden merely by the curvature of the earth, I would expect less of the bow to be visible as well.

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Perhaps you never built model WWII ships. The shape of the deck is typical, with a higher bow and stern and a lower midships.
Even the Queen Mary has such a curve in all the decks, and it was built BEFORE WWII.
The curve you see is in the ship, not the water. Try a straightedge. The water makes a perfectly straight line from left to right.
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So I don't know.  I'd want to see pictures and measurements taken scientifically where all the factors are known:  distance between the observer and the target, height of the viewer above sea level, height of the target above sea level ... taking into account wave conditions.

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You ought to take a trip to a nautical museum and ask your questions. They have plenty of data you can sort through. Find a submarine captain (I've spoken to one) who can answer your questions. Try watching some WWII submarine movies with moving images of what the periscope showed. This isn't rocket science.
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But if you do speak to a sub captain, be prepared for some straight talk. They don't mince their words.
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If you tell a sub skipper that you think the earth is "flat" he might give you a real treat of Old Salt linguistics.
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I think you are right.  I think what we see through the telescope is the water meeting the sky.  Like the video shows, it's just "perspective."  Our vision causes objects that are farther away to appear smaller and smaller, until mountains look like they merge into the ground and even the clouds in the sky seem to fall to the ground.  

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Why do flat-earthers keep claiming the earth is "flat" when everyone knows it's not?

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Quote from: hismajesty on February 19, 2018, 02:51:27 AM

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Ladislaus,
What you have to understand is that flat earthers are not the ones proposing a model. 

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You have to have some idea of a model.  If you KNOW that the earth isn't a globe, then you have to have SOME idea of what it actually is.  I've seen the commonly-used flat earth map for instance (that's a model).  I'm actually exonerating flat earthers if the model cannot currently explain every detail ... because they don't have the scientific apparatus behind them to actually get any precision on the model.  Right now the model is purely speculative.

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Ladislaus, you're wasting your time asking about a "flat-earth model" because flat-earthers won't give you one.
They revert to the fallacy that denies the necessity of principle, because they don't operate on principles.
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Flat-earthers deny the necessity of principle. 
They don't want to have a model because they know there is no such model that can stand up to simple tests.
Every model they have tried (and there are many) fails for one or more simple reasons.
Since they know they cannot produce a working model, they rely on the false premise that they don't need one.
The simple principle that says, if the earth is "flat" a working model is a direct consequence, is what they reject.
They deny the necessity of producing a working model because they deny the principle that demands it.
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So on The Flat Earth "Model," ships disapear over the horizon from the top down.  Hence, ships would be visible, before submarines would be.  

Define "model"  

Pope Urban VIII condemned the notion earth was a globe.

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Did you wake up having a nightmare again?
One of your recurring nightmares?
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