# Earth curvature refraction experiments - debunking flat/concave Earth

Thank you for the replies.
Refraction is something I'm trying to understand, really how I have always seen refraction is light bending things that I can already see. I don't think it is critical for me to say 'okay that settles it, but I don't quite understand how refraction works in these situations.'

Chew, I am looking into curvature, it seems very, very clear cut, if the earth is a globe then we should be able to test this quite easily. This is one video of many showing no curvature, but it does not seem so clear to me given the simple marks I put on the pictures. Also there are plenty of videos showing no curvature, none. One video is not enough ground to dismiss all the others that show the opposite. Ultimately I will have to test it for myself.

If you believe the earth is round you should try and test that it is flat. Really there is no reason not to, it really should be simple, and I have seen better tests that one guy walking to the beach and zooming in with no building, the argument that it is a mirage is equally as valid as with debunking a flat earth one.
Testing a theory you believe imo shows you got the results you were looking for, think climate change, pesticides etc..

All in all I am not convinced, Socrates said 'I know that I know nothing', I think he has stood the test of time because there is some truth in his words.

Mind you thinking 'maybe the earth was flat' was not easy and I believe I was able to think about it without ridicule as a result of some serious reevaluation I have been doing over nearly the past year of any believe system I previously held.
Much love

Thank you for the replies.
Refraction is something I'm trying to understand, really how I have always seen refraction is light bending things that I can already see. I don't think it is critical for me to say 'okay that settles it, but I don't quite understand how refraction works in these situations.'

Chew, I am looking into curvature, it seems very, very clear cut, if the earth is a globe then we should be able to test this quite easily. This is one video of many showing no curvature, but it does not seem so clear to me given the simple marks I put on the pictures. Also there are plenty of videos showing no curvature, none. One video is not enough ground to dismiss all the others that show the opposite. Ultimately I will have to test it for myself.

If you believe the earth is round you should try and test that it is flat. Really there is no reason not to, it really should be simple, and I have seen better tests that one guy walking to the beach and zooming in with no building, the argument that it is a mirage is equally as valid as with debunking a flat earth one.
Testing a theory you believe imo shows you got the results you were looking for, think climate change, pesticides etc..

All in all I am not convinced, Socrates said 'I know that I know nothing', I think he has stood the test of time because there is some truth in his words.

Mind you thinking 'maybe the earth was flat' was not easy and I believe I was able to think about it without ridicule as a result of some serious reevaluation I have been doing over nearly the past year of any believe system I previously held.
Much love
Hello Gattaca,
Let me explain my position. I studied astronomy and physics. am a teacher now. Part of my astronomy study was "history of astronomy". There I learned that the concept of a round earth is something the ancient greek philosophers starting with the pythagorean school (ca 500 BC) almost without exception adhered. And they had good arguments for that, still valid today: ships disappear behind the horizon, from a higher standpoint you can see further away, the shadow of earth cast upon the full moon during a lunar eclipse is always round and when moving south, the position of Polaris becomes lower and at the same time you see new constellations appear above the southern horizon. With the exception of a few early medieval christian scholars that rejected in principle every thought of the pagan ancients and wanted the shape of the earth resemble that of the tabernacle, every scientist understood these arguments and nobody argued against them. The last argument has even become stronger since from the southern hemisphere we can see the night sky rotate around the South Celestial Pole -- clockwise, whereas the stars rotate anticlockwise around the North Celestial Pole (Polaris).
If you want to see the curvature I have only one advise: think big. The ancient Greeks had the advantage of living next to a sea with a lot of small islands. And their coastline was next to high hills and mountains. So for them the evidence was clear. If you wanted to be the first to see a ship coming towards you, you would climb a high hill next to the shore. Also they saw islands further away lying more and more below the horizon. And then you have to think of tens of kilometers. Most flat earth video's are about a few kilometers, use the wrong math and struggle with difficult things like refraction, beam divergence or whatever. I myself had the opportunity to photograph windmills that were standing in the North sea at distances between 35 and 45 km. Both from the beach and from a dune at 24 m high. I could clearly see the effects that the ancient greeks described. I calculated what the amount of hidden windmill had to be and it matched the observations neatly. So I did my own test indeed.
If you would like to see the curvature of the horizon I can give you the calculation based upon which you may conclude that this is very hard to see from altitudes up to 20 km above the surface of the earth. And photographing it is always tricky due to lens distortion. Which goes both ways by the way. Images from balloons etc show some times to much curvature and other times to little. The only clear photographic evidence comes from the images taken from the ISS or of the planet as a whole made by spacecrafts of the Japanese, Indian, Chinese, Russian, European and american space agencies
Besides that I know the evidence for a rotating earth moving around the sun. Astronomers have to deal with stellar parallax, stellar abberation, doppler shift and more, all caused by the movements of the earth. For some taking these effects into account with their measurements, is their daily business.

If you believe the earth is round you should try and test that it is flat. Really there is no reason not to, it really should be simple

Might I recommend my post 'Simple Proof for Convexity of Earth'?

The essence of which is observation of the Sun (or you could use the Moon, or even a mountain peak) at different distances (from the subsolar/sublunar/peak) and noting that the results absolutely exclude the ground being a flat plane.

On a flat plane you can triangulate the height 'h' given your distance and measuring the angle to the point B.

Consider:

You can also get this angle by using a vertical stick of a known height and measuring the shadow length of the Sun - which is one of the methods I cover in my post.

Slope is simply "RISE/RUN" and a slope of 1 gives you an angle of 45 degrees as shown above. This happens when h is equal to d.

If we double our "RUN" (2 * d) then we halve the slope: RISE/(2*RUN)

It doesn't matter what 'h' or 'd' are at this point, we KNOW that if we double the distance we will get a slope of 0.5 which gives us an angle of about 26.565 degrees - as you can see above.

For simplicity I describe this situation - consider the Equinox where the Sun is very very close to directly over the Equator at your solar noon time (not LITERALLY 12:00 because timezones aren't perfect but the moment when the Sun reaches the Zenith on the Equinox for your longitude). At 45° North latitude an observer would see the Sun at almost exactly 45° above THEIR horizon.

That is ~3105.2 miles from the Equator which would IMPLY that the Sun is 3105.2 miles up BUT ONLY IF THE GROUND IS FLAT.

What happens if we go up to say 70° North latitude? We would find the sun at ~20.04° but that would mean the sun is only 1761.7 miles up! And every latitude we try we get a DIFFERENT triangulation for the Sun. At the North Pole the Sun is on the Horizon. That is TWICE your distance to 45° - but the Sun is no where near 26.565° - doesn't take rocket science to realize this model is completely busted.

This means the ground is not flat but our horizon itself is rotating causing the APPARENT angle to change, not the actual geometric angle.

And if you look at measured shadow lengths for the sun at different latitudes you'll find that they follow a power function and not a linear function as would be predicted by a Flat ground.

Spheroid Earth:

Flat Earth:

And I took the Fall 2008 data from the Noon Day Project where a few school kids around the world have actually done this experiment many times and I plotted it out - sure enough, we can eek out the curvature even from this data:

This is an experiment you and a few friends around the globe can carry out and you can KNOW that the Flat model is busted by your own measurements using nothing more than a straight stick, a plumb bob, a good measuring tape, and some care in measurement.

You don't even have to wait until the equinox - just do it today and check the shadow length against one of the Shadow Length or Solar Angle calculators.

Nearby Sun Impossible
Horizon Always Rises To Eye Level?

Has this link been posted yet? I didn't see it.

http://www.abc57.com/story/31830937/skyline-skepticism-the-lake-michigan-mirage

It's an interview with the photographer of the Willis Tower mirage pic. He says it was taken from "the park to the south" - Warren Dunes State Park - and that the conditions were very unusual that day.

I did a write up on the Nowicki images of Chicago a little while back.

I composed one side-by-side with one of his mirage timelapse videos which I think excellently shows how much refraction is going on and how it works (note how mostly it is the water which appears to lower and less frequently the buildings will 'loom' up).

From this video:

And in this image from the other video which was on the news:

You can see Willis Tower is pretty stretched and the buildings to the right of it are "flat topped" (which isn't how the skyline appears). Lots of refraction & mirage effects are clearly evident.

This image was taken from Grand Mere State Park (according to Nowicki) where I estimated the viewer elevation was about 17.5m over the lake and I show that the view is entirely consistent with globe Earth.

0% refraction: d=90933, h=17.5, R=6368780 = 453m
10% refraction: d=90933, h=17.5, R=6368780*1.10 = 404m
20% refraction: d=90933, h=17.5, R=6368780*1.20 = 364m <<< most closely matches view & 'unusual' conditions

This image was taken from Grand Mere State Park (according to Nowicki).
Clicking on the twitter link, he says in the third comment down that the time lapse video is from Warren Dunes State Park, and also says the same in the abc57 article about the photograph.

I think he mistakenly posted it as Grand Mere in the beginning, and it kind of stuck.

The top of the dunes at Warren is about 71 metres above the level of the lake.

if the earth is a globe then we should be able to test this quite easily.

Not so easy, because of the scale of things. The radius of the curvature is so large and refraction affects observations close to the surface, where we Humans mostly hang out.

Clicking on the twitter link, he says in the third comment down that the time lapse video is from Warren Dunes State Park, and also says the same in the abc57 article about the photograph.

I think he mistakenly posted it as Grand Mere in the beginning, and it kind of stuck.

I appreciate you pointing out this potential issue but on careful review (and I agree there is room for some confusion on the location) but I don't think it is the case for this specific image. And Warren Dunes is slightly closer so I'd happily take Warren Dunes But I really think this specific image is from Grand Mere and here is all the relevant information I could find (but always open to additional info!).

The photo I used is not in the mentioned timelapse video, which I agree is definitely from Warren Dunes but is dated the next day after the photograph. Check out "Looking toward Chicago from Grand Mere State Park 4/28/2015" and there are 4 or so other photos taken on 4/28 tagged Grand mere also; and several on 4/29 all tagged Warren Dunes. So I think he just visited both locations 1 day apart.

(note: my side-by-side comparison is from yet another timelapse, tagged Grand Mere).

The same pic posted on http://www.abc57.com/story/31830937/skyline-skepticism-the-lake-michigan-mirage says it's Grand Mere -- I think they just ALSO talk about going out to Warren Dunes ("We climbed the dunes to find out." - but this is in April 2016) and taking some more images and that is the confusion. But this original pic is dated April 28th, 2015 but not from the timelapse taken on April 29th, 2015 from Warren Dunes. The sky is very different on the two days.

No mention of Warren Dunes in the FB post.

The original ABC57 article from a year prior also contains this same image and says Grand Mere. So this image was clearly taken a year prior to the later article.

And contrast with the similar pic that is from Warren Dunes

None of the images I could find were geotagged but since the video timelapse and this image are completely separate items and all sources confirm Grand Mere for the still photo I think I have to stick with that for now.

It changes the analysis very little if it's a bit closer in Warren Dunes, works in favor of Earth curvature actually.

I've no issue with needing about 20% refraction to see this view because they confirm that this view is VERY unusual to see.

“Earlier this year there was a good opportunity, It looked like 40 or 50 buildings which is the most I've ever had the chance to see."
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The only thing that seems confusing about the location is the ABC57 article which doesn't seem as likely to be correct as Nowicki's several sources for this specific photo (that weatherman doesn't seem to have the details very solid, he said you can see almost to the shoreline which is clearly not the case with entire buildings missing). But I can't rule out the possibility. Hard to say without more information I think.

So review that and let me know what you think. And again, I truly appreciate your feedback.

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Good work.

I guess I was letting my busyness prevent me from properly checking my memory - which turned out to be faulty this time.

Happy to be wrong!

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Good work.

I guess I was letting my busyness prevent me from properly checking my memory - which turned out to be faulty this time.

Happy to be wrong!

Ok, glad we are in sync. Happy to double check, it's my responsibility

For fans of south Wales here are some photos of it disappearing. One is from my garden and the other from higher up. Looking towards Cardigan and Strumble head from Aberystwyth. I cannot see the Strumble lighthouse light from home, but can see the beam on the clouds under good conditions. Hewers amongst you may spot a shoal of mackerel.
Some more pictures of the same view from yesterday. From a height of 52, 62 and 125 metres. Also a zoomed photo from 125 metres of what is probably the ferry, from Fishguard to Ireland, passing Strumble Head at 50 miles.

This is the position of the ferry at that time (coordinates in top right corner)

(Location is the second triangle from the left, below the zero of "20")

Camera time is GMT, and 2 minutes fast. I don't know what else it could be in that position, other than perhaps a fishing boat. Been round there a few times and only saw the ferry..
Looking in the same direction from about 5 miles, from memory. You can just see the lighthouse as a white spot at the tip of the land.
^
I just noticed from the above photo that we still seem to be missing a vital bit of Wales from 125 metres - Strumble Head!

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Basically adding in the altitude of the city or spot you at and the altitude you are wanting to view or are in question of. If that new page got more advanced;
it could use google maps or some map site where you would pin your spot;
pin the spot you are wanting to view;
get technical data of both locations;
then tell them how much is blocked, or at what extra height they would have to be at in order to see that spot with or without a telescope.

I only ask this because it only assumes both objects are at sea level and not a land to land with various altitudes.

I only ask this because it only assumes both objects are at sea level and not a land to land with various altitudes.

You can enter in the viewer height, and it tells you how much would be blocked by the ocean.

You can't really do it over land, as you need to account for all the different terrain in-between. The best way I've found of doing that is to use Google Earth, and just see what you can see in GE.

Maybe you could give an example of what you want to calculate. You might want to read through this thread first though.

Having grown up in Chicago on the shores of Lake Michigan, and spending many summer weeks in upper Michigan on the shores of Lake Superior, it's hard for me to even conceive of people having an issue with this. I've probably watched a thousand motorboats, sailboats, freighters, etc. vanish on the horizon bottom first.

In Chicago you can see the pumping stations out in the lake and then take a boat out to them and clearly see that they're taller than they looked from the beach and then look back to the shore and realize you don't see the parks, piers, street lights that line most of the shore. Also, the John Hancock building has an extremely visible pattern of Xs going up the side, although it never occurred to me to count them, they would make for a great marker.

Sorry all I can add to the conversation is anecdotal observations... it never occurred to me all those years ago the FE "controversy" would even be a thing.

If they think this is evidence, then why don't they do 100 miles, at 3 feet elevation?

Arguing with flat earthers (or concave earthers) is generally a waste of time. Many of them are essentially just trolling - arguing a case as a funny intellectual exercise. Then there are some who take it more seriously who use the work of the first group, but often don't really understand it.

But back to this, it seems like a variation of the eponymous "Bishop Experiment"
http://wiki.tfes.org/Experimental_Evidence

California Monterey Bay is a relatively long bay that sits next to the Pacific Ocean. The exact distance between the extremes of the Monterey Bay, Lovers Point in Pacific Grove and Lighthouse State Beach in Santa Cruz, is 33.4 statute miles. See this map.

On a very clear and chilly day it is possible to see Lighthouse Beach from Lovers Point and vice versa. With a good telescope, laying down on the stomach at the edge of the shore on the Lovers Point beach 20 inches above the sea level it is possible to see people at the waters edge on the adjacent beach 33 miles away near the lighthouse. The entire beach is visible down to the water splashing upon the shore. Upon looking into the telescope I can see children running in and out of the water, splashing and playing. I can see people sun bathing at the shore and teenagers merrily throwing Frisbees to one another. I can see runners jogging along the water's edge with their dogs. From my vantage point the entire beach is visible.

IF the earth is a globe, and is 24,900 English statute miles in circumference, the surface of all standing water must have a certain degree of convexity--every part must be an arc of a circle. From the summit of any such arc there will exist a curvature or declination of 8 inches in the first statute mile. In the second mile the fall will be 32 inches; in the third mile, 72 inches, or 6 feet, as shown in this chart. Ergo; looking at the opposite beach 30 miles away there should be a bulge of water over 600 feet tall blocking my view. There isn't.
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Actual images of people playing on a beach would be much more significant evidence than some flashes of light. So why not simply take a photo of someone standing on the Antioch Pier, from the Benicia viewpoint?

And given that there are literally millions of combinations of locations in which you could do this simple experiment with a telescope, and millions of people who own telescopes, then why is the internet not flooded with millions of examples of this evidence?

If I still lived near the sea, I'd pop down an try to take photos of the beach at Point Dume (20 miles from Venice).

Mick, I was staying in a beach house near Monterey and thought of you and this post. Here is a photo, through a scope, of a known landmark from across the bay in Santa Cruz. I've annotated some of the factors and assumptions in the photo itself. -Michael

I have some questions about the curve calculator. 2 days ago it was producing wrong results for some reason. I first used it and it gave me correct results, then someone said my results were wrong, so I checked it again and it still gave me the same correct results. Then the next day I checked it again and it gave other results, which were not correct. I calculated for myself that they were not correct. Then some time later I checked it again and it gave me the original and correct results again.

Anyone know what happened? It was not a result of me entering the wrong data.

My other question is about the horizon dip. Is this the amount of degrees the horizon drops from a line of sight that is level in relation to the surface that the viewpoint is above?

Anyone know what happened? It was not a result of me entering the wrong data.

Nothing has changed with the calculator. Maybe you selected metric.

My other question is about the horizon dip. Is this the amount of degrees the horizon drops from a line of sight that is level in relation to the surface that the viewpoint is above?
It you click on "Advanced" you get the following explanations:

Tilt is angle between vertical at the two locatons
The amount a distant object is leaning away from you
d/r = 21120.00/20903520 = 0.00101036 radians, *180/PI = 0.05788914 degrees
Horizon Dip is the angle that the horizon is below level
as seen from the viewer height

It's arcsin(a/(r+h)), or arcsin(15838.00/(20903520.00+6.00)) = 0.00075767 radians, *180/PI = 0.04341137 degrees
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The International Space Station flies approximately 400 kilometres over thunderstorms visible during a nighttime pass. In this image, lightning can be seen flashing brightly inside the clouds below. A Russian Soyuz spacecraft (left) and Progress spacecraft (right) are seen in the foreground.
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- Cosmos Magazine

This may be a touch off topic...if so, I apologize and please feel free to move this to a more suitable location. I just happened to run across this really sweet photo from the ISS. Ive been hunting around for what this is an actual image of (other than the storms) but havent been able to find anything concrete yet (then again Im at work so more than quick cursory google searches are difficult). The point to all this is the fact that you can very clearly see the curvature of the earth in the photo (and its just a really cool pic from the ISS) from a relatively close orbit.

on the metabunk calculator, what is the difference between "hidden" like on the basic earth curve calculator and the "drop" on the metabunk calculator? steven hawkins has a video on proving the earth is round and they had a boat go out 3 miles and using a laser 2ft off the surface, saw the laser move up the boat 6ft to be seen. this matches the "drop" distance for 2ft observer and the distance of 3 miles, BUT, not the "hidden" value , of near only 1ft. which is correct?

on the metabunk calculator, what is the difference between "hidden" like on the basic earth curve calculator and the "drop" on the metabunk calculator? steven hawkins has a video on proving the earth is round and they had a boat go out 3 miles and using a laser 2ft off the surface, saw the laser move up the boat 6ft to be seen. this matches the "drop" distance for 2ft observer and the distance of 3 miles, BUT, not the "hidden" value , of near only 1ft. which is correct?

"Hidden" is how much of a distant object is hidden from a particular camera height.

"Drop" is how much the ground drops below flat at that distance. It's the same as "hidden" with a camera height of zero (i.e. if you were looking exactly at sea level). Generally though the camera is above sea level, so "hidden" is much less than "drop"

The Hawking's experiment is discussed here:
https://www.metabunk.org/lake-balat...vature-of-the-earth-if-any.t7780/#post-186843

Helicopter version here:
https://www.metabunk.org/stephen-hawkings-genius-helicopter-demonstration-of-lake-curvature.t7834/

I think i get it.. i had to start thinking in terms of the horizon going down.. when i plugged 6 feet at 3 miles, and the horizon was 3 miles as well, it all became clear.. YOU CAN SEE IT all, (its not obstructed now, but you need to look down to see the prevoius point that was viewed when closer) but the laser dot will go up on the flag pole on the boat by 6ft, because that is the horizon that has gone down.....maybe you can make the calculator more clear there. the Flat earthers , are getting this (along with most physics,math , geometry and other facts) wrong!!

Hi all! I shot some pictures today. I wanted to share my results with you all.

So the distance was 11km, I used a tape measure to measure cameras height above sea level and it was 45cm.

What to make of these results?

Hi all! I shot some pictures today. I wanted to share my results with you all.

So the distance was 11km, I used a tape measure to measure cameras height above sea level and it was 45cm.

Can you give the coordinates of your camera, and of that white tower structure in the center of your image?

Can you give the coordinates of your camera, and of that white tower structure in the center of your image?

Sure, just a sec

camera

white tower (my best guess)

just to get an idea of how the place looks like close up

in this pic I took from exact same position the tower is behind the boat maybe it helps

This one might help also to identify features better

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just to get an idea of how the place looks like close up
I think this pic is better... the aborites in your first pic are to the farthest right in below pic (pretty sure)... unfortunately so many boats is covering the 'tower' ( side of a house.

Google Earth puts the sidewalk just in front of the green building at 10 feet above sea level. So the bottom 5.5 feet of the green building should be hidden.

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I think this pic is better... the aborites in your first pic are to the farthest right in below pic (pretty sure)... unfortunately so many boats is covering the 'tower' ( side of a house.

Yeah.. but I think there is a possibility that the "tower" is behind the cameraman here.. because my angle was waay off from this.. nice pic tho

Google Earth puts the sidewalk just in front of the green building at 9 feet above sea level. So the bottom 6.5 feet of the green building should be hidden.

google earth is very unreliable when it comes to this.. for example there is a road above the place I took the pic from.. it reads 1m on google earth.. and in reality it's about 5m.. and many vice versa examples..

I guess the easiest way I can come up with is measure the height of the green line I drew here.. from sea level to top of the window.. then compare to my picture from sea level to top of the window.. but I have to sleep now.. very late here.

I guess the easiest way I can come up with is
you could jet over there and hold an altimeter up to the door at that level

I used a tape measure to measure cameras height above sea level and it was 45cm.
Seems possibly low. What was the camera on exactly?

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