1. wonderland78

    wonderland78 New Member

    New to this forum but I signed up because a) I'm concerned about the whole flat earth issue in that people are stubbornly asserting its validity and b) they all seem to know some version of 'science' to significant degrees and so I need to educate myself in order to, well, debate them properly.

    So yeah, as I'm new, I just hoped I could post someone's argument and see if I could get some helpers with it. Hope that's ok. Here's what they assert:

    and one more

    Thoughts?
     
    Last edited: May 2, 2017
  2. Mick West

    Mick West Administrator Staff Member

    They need a specific example, or at least something more specific.

    Telescopes just make things bigger. If something is hidden beyond the horizon then you won't be able to see it with a telescope.

    It's demonstrably false.
    [​IMG]

    I zoomed in on this boat. I could see the sail with the naked eye. The bottom of the boat was still covered. Then I stood up so I could see over the horizon and the boat appeared.
     
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  3. wonderland78

    wonderland78 New Member

    Thanks, this is quite useful. Only a video would be more useful I guess. I hope they wouldn't then assert that if you zoomed further that the bottom would eventually be found. It's clearly behind the water.

    No doubt they'll have an answer though.
     
  4. Z.W. Wolf

    Z.W. Wolf Senior Member

    [OP copied-in full-removed to help shorten reading time]


    There's so much confusion here I'm reluctant to even start but...

    Confusing perspective and resolution. See this for an introduction on resolution: https://www.metabunk.org/explainati...ther-gravitational-lending.t8592/#post-204831

    No such thing has ever been done. It's just something FE believers keep telling each other. There are some YT videos that purport to show this, but they are just confusing resolution with "bringing something back from over the horizon." For instance they zoom in on a ship and then zoom out until the camera lens is in wide angle. The ship disappears from the video. But that's just because the image of the ship is too small - poor resolution. Then they zoom in again and it reappears. But it reappears because of better resolution.

    Once again this is a problem with resolution.

    It's not how far we can see. It's how small we can see. Something far away looks small, yes? But can you see a single bacterium with your naked eye if it's on a table top? (The answer in one case is "yes." There's one species of bacteria that's just big enough to see: Thiomargarita namibiensis.)

    There are problems with the human lens and pupil size that are too technical to get into, but another problem is: The rods and cones in the human retina have a physical size. Any image on the retina that's small enough is only going to stimulate a critically small number of them. There will be no detail. This bit about the match at 30 miles is a distorted description of being able to see a source of light on a dark night which is just bright enough to see in the darkness but which has no detail. It's a dimensionless point of light. Stars are another example. We see them, even through a telescope!, as dimensionless points of light. Whereas planets like Venus and Jupiter are just big enough to look like an object with dimensions with the naked eye. Go look!

    Obviously we can see things farther away than 30 miles... if they are big enough. Do the sun and moon disappear at 30 miles?

    So things "disappear" simply because the image size gets too small. There's no set mileage of course. It depends on how big it is, doesn't it?

    Weather conditions and air matter too. But light itself doesn't "get all pixelated."

    There's no such word as "contrastive" but contrast is also important. Think about this. You can see car headlights on a road tens of miles away... on a dark night! But could you see a car headlight that far away during the daytime? It would be too small. Poor resolution. But the car headlight at night is still shining a number of photons into your eye. You can see the light, because there are no other photons (from daylight) drowning them out. But there's no detail. It's just a point of light.

    Further reading: http://www.bbc.com/future/story/20150727-what-are-the-limits-of-human-vision


    This is an argument from personal ignorance. The author of this quote doesn't know anything about the history of astronomy and geodesy, so he apparently concludes that it doesn't exist. We're supposed to stick to one subject per thread here, and the history of astronomy and geodesy fills books.
     
    Last edited by a moderator: May 2, 2017
  5. Trailblazer

    Trailblazer Moderator Staff Member

    Yes, I had this video shown to me as an example of "zooming in bringing a ship back into view":


    Source: https://www.youtube.com/watch?v=PueURw-Twg0


    The boat disappears when zoomed out!

    upload_2017-5-3_11-33-17.

    Even thought it is clearly way in front of the horizon:

    upload_2017-5-3_11-34-15.
     
  6. Mick West

    Mick West Administrator Staff Member

    Not only that, it's clearly in front of the horizon and the same shape (i.e. the bottom is not missing) through the entire zoom back right up until it's smaller than the resolution of the camera.

    20170503-080310-5e9zs.

    Even of the very last frame it's perceptible in the video, the wake of the boat is below the horizon:
    20170503-080753-h8fo7.

    "Zooming in to look over the horizon" has always been an odd claim since Rowbotham made it in the 1860s. It flew back then because hardly anyone had access to a telescope. But now lots of people have cameras like the P900 - or at least can examine videos like this - and can see that it's false.

    Of course the challenge here is that the FE believer fundamentally misunderstands what they are seeing, and are highly resistant to explanation. Perhaps some kind of socratic dialog while looking at this video might help:

    (invented example dialog follows)

    Globe: If the earth is flat, then why do ships sink below the horizon?
    Flat: It's the Law of Perspective, if you zoom in on it the ship will reappear
    Globe: Do you have an example?
    Flat: yes, look at this video: Nikon P900 fishing boat that merges with horizon becomes visible under zoom
    Globe: So where is that boat behind the horizon
    Flat: 20 seconds in, you can see it's vanished
    Globe: But you can see the wake of the boat. Doesn't that mean you can see the bottom of the boat
    Flat: Maybe, but it's merging with the horizon
    Globe: Isn't the claim that the bottom will vanish first? At 19 seconds in I can still make out the wake, but not the boat.
    20170503-082456-lytno.
    Flat: It become visible as you zoom in!
    Globe: It looks like it's just getting bigger, and look, even at 18 seconds it's in front of the horizon. This isn't a boat going over the horizon at all:
    20170503-082559-ly7nt.
    Flat: But you can't see it, then you zoom in and see it.
    Globe: Can you give an example where the boat is actually hidden by the horizon?
    Flat: Can you?
    Globe: Here. This video shows two similar sized boat, but this time they are actually "hull down" - the bottom portion is hidden by the horizon.

    Source: https://www.youtube.com/watch?v=3lnJZNanTIw


    Here's no zoom where you can see the sails.
    20170503-083531-s5vyp.
    A little bit of zoom:
    20170503-083308-r7lcl.
    Flat: So zooming in will reveal the hull
    Globe: No, if you zoom in the same amount is hidden
    20170503-083359-60kqh.
    20170503-083636-v8rlz.
    20170503-083737-mv6s7.
    Flat: That's just waves
    Globe: Look at the building behind the boats at the start of the video. They are obscured by the horizon too. If it's just waves, why do we never see the bottom of the building or the beach?
    Flat: Perspective
    ..... etc .....
     
    Last edited: May 3, 2017
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  7. OTACHI

    OTACHI New Member

  8. Mick West

    Mick West Administrator Staff Member

    Can you summarize the explanation?
     
  9. OTACHI

    OTACHI New Member

    Here's the description:

     
  10. Mick West

    Mick West Administrator Staff Member

    So in that explanation there are nearby waves that are higher than eye level which block the boats.

    The problem there is that the ocean horizon is measurable slightly below eye level. For waves to block your view of the boat they would have to be higher above sea level than your eyes/camera.
     
  11. OTACHI

    OTACHI New Member

    Well obviously in flat earth the ocean horizon is always at eye level.
     
  12. Mick West

    Mick West Administrator Staff Member

    And that's especially problematic with larger more distant object viewed from higher up.
    20170313-094520-f0g0s.
    Even at six feet it's quite apparent that there's no waves more than a few feet high, and nothing nearby is blocking my view.

    In fact we can see the surface of the ocean for several miles out.

    The wave theory is even more impossible when you look at the 40 foot view.
     
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  13. Mick West

    Mick West Administrator Staff Member

    Why can you see it then? Notice in my pics above the horizon is a sharp line when viewed from a few feet up. It's also in front of the island, and not behind it. So what are we seeing? What is the the horizon in the above three photos of Catalina Island (or the boat pictures)
     
  14. Henk001

    Henk001 Active Member

    Another example. Two photographs of a windfarm in the North sea with windmills at a distance between 36 and 45 km. First made while standing on the beach. Second while standing on a 24m high dune. Also Notice the buoy, that shows that you can see further away when your standpoint is higher.
    upload_2017-5-3_20-20-8.

    upload_2017-5-3_20-21-20.

    Same distance, same zoom.
     
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  15. OTACHI

    OTACHI New Member

    Hmm,you're right,thanks Mick.
     
  16. deirdre

    deirdre Moderator Staff Member

    if that were the case then the boat wouldn't unshrink if you increase your viewing height.
    106 distance to horizon.
     
  17. Henk001

    Henk001 Active Member

    Same windfarm different standpoint. 55 km away standing on a 28 m high dune.
    upload_2017-5-3_20-32-10.

    Center part cropped contrast enhanced
    upload_2017-5-3_20-33-14.
     
  18. Trailblazer

    Trailblazer Moderator Staff Member

    Yes, big things like islands are a much better example than boats, because they are large enough to be clearly visible with the naked eye even at a distance where a significant portion of them is hidden over the horizon. And nobody can argue that an island several hundred feet high is being obscured by "nearby waves".
     
  19. Trailblazer

    Trailblazer Moderator Staff Member

    This is a really good photo. To me, at least, the three-dimensional "hump" of the ocean, with the wind turbines behind the "summit", is very visually apparent.
     
  20. JL Born

    JL Born New Member

    I have a flat earth friend and sometimes it is super hard to explain stuff, so for this example, if we can only see 30 miles, why can we see stars? I know light travels, but how far can our eyes really see with no atmospheric turbulence?
     
  21. Mick West

    Mick West Administrator Staff Member

    The example was a candle, visible from 30 miles away in ideal condition. The limit is because a candle is small and dim. If you have something bigger and/or brighter, then you can see it from a longer distance.

    While interstellar distances are really large (one light year is about 6 trillion miles) stars are also really large. Our sun is a pretty dim star, and it puts out 3.75×10^28 lumens, with is about 3x10^27 (3,000,000,000,000,000,000,000,000,000) as much as a candle. There are also lots of much bigger stars - and some of the things you see in the sky are actually galaxies made up of billions of stars.

    So there's no real limit, if the light source is big enough.
     
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  22. Whitebeard

    Whitebeard Senior Member

    Early off shore lighthouse such as the Eddystone and Bell Rock lighthouses were powered by candles. Older on shore lighthouses traditionally used coal or wood fired braziers, but could consume over 800 tons of combustibles per uear, fine when your on land, but when your in a slender tower, x number of miles out to sea and often isolated for months on end this was not practical. So when Henry Winstanley was commissioned to build the first Eddystone Lighthouse in 1698 he experimented with a number of light sources and discovered that ordinary tallow candles, in a bank of up to 12 (increased to 24 for the second and third lighthouses 1709 & 1759 - the original building having been destroyed in a storm in 1703) magnified by a large mirror and a simple lens was more than adequate to be seen upto 20 nautical miles away, with the added advantage of being easier to store, transport and handle than oil for oil lamps. In fact it wasn't until the 1850's that oil fired lamps began to replace candles as the standard means of lighthouse illumination.

    (Source - The Lighthouses of Trinity House - by Richard Woodman and Jane Wilson, 2002, (ISBN: 9781904050001) )
     
  23. Trailblazer

    Trailblazer Moderator Staff Member

    And you can see things much further than 30 miles away, no candles in darkness required. I've posted this photo before, but this mountain was perfectly well visible with the naked eye (otherwise I wouldn't have known to take the photo!).

    [​IMG]


    upload_2017-7-27_11-52-12.

    Almost 85 miles from the camera location in Tongariro National Park to the summit of Mt Taranaki, in New Zealand. The increasing haziness caused by the atmosphere shows up well on the successive ridges, but you can still see.