The Flat Earth Society

Flat Earth Discussion Boards => Flat Earth Theory => Topic started by: shootingstar on January 10, 2019, 02:54:09 PM

Title: Seeing the curvature of the Earth directly
Post by: shootingstar on January 10, 2019, 02:54:09 PM
One of the most common responses given by flat Earth believers to the FAQ 'Why do you believe the Earth is flat?' is because it looks flat. I believe that Tom once answered this question along the lines of

"If I emerged from my cave for the very first time and looked at the mammoths cavorting on a broad expanse of tundra, I surely wouldn't quickly assume I was standing on a sphere"

I quite agree with that comment. I am pretty sure many of the present day indiginous tribes of remote parts of the world who have never travelled more than a few miles away from their settlements would agree too if the question was put to them.  They have not been educated with any skills and knowledge beyond what they need to survive day to day and year to year. As long as those people can catch food, have shelter and can live their lives in relative safety and comfort I am sure it doesn't matter to them what shape or size the planet they live on is.

The perception of the world that these people have is limited to their experience of it. If we were to show them photos or videos of big cities, high mountains, the polar regions or even the oceans they would seem completely alien to them. Why? Because they have never experienced them. I have a limited view of the world from my window and if I had never read a book, switched on my radio, TV, or computer then my knowledge of the world would be limited to what I can see. Would that give me justification to assume whatever I see outside of my window is much the same as what everyone else in the world sees outside of their windows?  How does someone who is blind from birth prove the Earth is round or flat.  The answer is they can't so they have to rely on information given to them by others. Why should they believe or trust what they are told?

Those who say that the Earth is round will give a measured value of the diameter of the Earth of 8000 miles give or take a few. That equates to a circumference of 26,000 miles again, give or take a few. A civilian airliner will cruise at an altitude of about 38,000ft. That is about 0.1% of 8000 miles.  Not enough to make visible any curvature of the Earth to the naked eye. Especially when you take into account that from 38,000ft you don't have a clear view (or should I say a clear enough view) to make an accurate judgement of what shape the Earth surface looks.


Given flat Earth believers don't acknowledge that anyone has been higher than about that altitude they have no reason to believe the Earth has a curved surface. They haven't seen it for themselves. RET believers on the other hand will take into account the images and video taken by astronauts on the ISS. The ISS is orbitting at an average height of 250 miles which is 3.1% of the diameter of Earth, or 31x the height of a civilian airliner at 38,000ft. That brings in enough of the Earths surface at once to now see the curvature. If seeing is believing then quite clearly they have good reason to believe the Earth is round.  They have seen a view of the Earth that many of us will never have and never will.
Title: Re: Seeing the curvature of the Earth directly
Post by: stack on January 11, 2019, 08:03:26 AM
Earth is big. Our eyeballs are very small in comparison. I always liked this simple demonstration for the "Well, it looks flat," remark:

(https://i.imgur.com/s4l9nY3.jpg?1)
Title: Re: Seeing the curvature of the Earth directly
Post by: Tom Bishop on January 11, 2019, 02:01:00 PM
The earth is observably flat by default. The possibility of it being a big ball, or whatever you imagine it to be, needs to be proven. It simply doesn't matter if you scream "you can't see it because it's an illusion!!1"

The fact that when we look at the matter closer and we find contradicting observations into the distance which support sinking and non-sinking is pretty telling. The fact that we have seen multiple long term timelapse of the horizon (https://wiki.tfes.org/Sinking_Ship_Effect_Caused_By_Refraction) which show that the light is constantly curving in the distance to make things appear to sink, and sometimes to unsink, is also telling. The fact that the famous sinking photos don't even match up with the stated curvature for the round earth, which we have looked at, is telling still.

There is no real evidence for the ball earth. Aristotile's proofs for a globe based on sinking ships and lunar eclipses are unsupportable.
Title: Re: Seeing the curvature of the Earth directly
Post by: shootingstar on January 11, 2019, 02:58:07 PM
Quote
There is no real evidence for the ball earth. Aristotile's proofs for a globe based on sinking ships and lunar eclipses are unsupportable.

And why is that then Tom? Just because you are not willing to accept those as proof of a round Earth?  You have already described them as 'proofs'.  What would you accept as 'proof'?  So given that you accept that the Earth looks flat by default, you cannot actually say as you have done before, that the best evidence for a flat Earth is because it looks flat.
Title: Re: Seeing the curvature of the Earth directly
Post by: ChrisTP on January 11, 2019, 03:25:57 PM
The earth is observably flat by default. The possibility of it being a big ball, or whatever you imagine it to be, needs to be proven. It simply doesn't matter if you scream "you can't see it because it's an illusion!!1"

The fact that when we look at the matter closer and we find contradicting observations into the distance which support sinking and non-sinking is pretty telling. The fact that we have seen multiple long term timelapse of the horizon (https://wiki.tfes.org/Sinking_Ship_Effect_Caused_By_Refraction) which show that the light is constantly curving in the distance to make things appear to sink, and sometimes to unsink, is also telling. The fact that the famous sinking photos don't even match up with the stated curvature for the round earth, which we have looked at, is telling still.

There is no real evidence for the ball earth. Aristotile's proofs for a globe based on sinking ships and lunar eclipses are unsupportable.
The double standards here... So much evidence of flat earth is contradicting. Misinterpreting data of a spheroid earth does not mean it's flat. Likewise, proving the earth isn't flat doesn't then make it spheroid either. This argument of "Must be flat because it isn't round" is getting old. Almost any flat earth evidence can be debunked.

Try telling a blind man the earth is flat... Under your own methods he is someone who cannot take your word for it because he doesn't see what you see. Because the blind man doesn't see a flat earth does that mean it's not flat? No, it means he simply cannot see if it's flat. Nor can he see it's round either. Should he trust his senses that tell him the world is a black void with no visibility? If so does that then mean that for everyone who isn't blind, their whole visible reality does not exist because that blind man said there's nothing visible?

The whole sinking ship thing is ridiculously anecdotal for everyone who tries it one or even a few times, there are so many factors that may change their results. elevation, tide, weather. Show me contradictory footage of sinking ships that are all under the exact same conditions otherwise it's pointless footage as evidence for either round or flat.

The sky is a clear indicator, we can observe other planets orbiting the sun and we can take our own positions into account to show we also orbit the sun. We can observe the moon orbiting us as well as other planets having their own moons. Where in any data regarding planetary movements contradicts the fact that earth is a planet? What do all planetary bodies look like?  spherical. How is that contradictory to the idea of earth being a spherical planet?

Looking out around the world it looks flat, this is what we expect to see on a giant sphere the size of earth compared to the size of humans. This isn't contradictory and we can easily see this to be the case simply by getting a camera and zooming in on a football/basketball/any kind of ball.

From what I can see there isn't much contradicting evidence of earth being a sphere, just cherry picked and misunderstood information. Meanwhile, you yourself switched from the standard flat earth model to a bi-polar model just yesterday to try to prove your point, both models completely contradicting each other while still both being inaccurate, then have the audacity to call anyone else evidence contradictory? Come on now...

If seeing is undeniably believing in your case then does that mean any magician is actually using real magic? All of documented history never happened and earth began the second you were born and opened your eyes?

A wise person once said if they cant agree on such basic stuff, then don't trust them on anything. So why if flat earthers cannot agree on basic stuff among themselves and with themselves, should we trust you on anything? Just looking at the flat earth wiki has so much content that does not agree with other content of the wiki. Why then should I trust your interpretation of any of the data that provides evidence of flat or round earth?

That wise person was Pete talking about NASA https://youtu.be/wKm5BgCVJwE?t=7191

So yeah, the earth looks flat if you simply look out. That doesn't mean it is flat though, a curve has been witnessed however inconsistently with the sinking ship effect, showing that not all is as it seems and that optical illusions exist with a simple glance so why then should you trust your own vision on this matter?
Title: Re: Seeing the curvature of the Earth directly
Post by: WellRoundedIndividual on January 11, 2019, 03:39:07 PM
The thing that baffles me is that it is openly admitted that other planets are round.  Of course, their argument is that the earth is not a planet and is unique.  Why is this so? Why wouldnt there be other planets that are flat?
Title: Re: Seeing the curvature of the Earth directly
Post by: AATW on January 11, 2019, 04:20:59 PM
The earth is observably flat by default. The possibility of it being a big ball, or whatever you imagine it to be, needs to be proven.
Correct. And it has been proven.
We have photos from space from multiple sources.
It simply doesn’t matter if you scream “they’re fake”. Hundreds of people and have been into space and seen it for themselves. 7 of those people are private citizens who have paid for the privilege. The ISS can be seen from earth. Satellite TV works. GPS works.

You have shown repeatedly that your understanding of physics is extremely limited. Your objections are simply you not understanding things and, worse, you refuse to listen to explanations.

Quote
There is no real evidence for the ball earth.
Only if you continue to not understand the evidence or call the bits you do understand fake. But you could do that about anything.
Title: Re: Seeing the curvature of the Earth directly
Post by: RonJ on January 11, 2019, 04:34:21 PM
Far out at sea the earth looks flat.  The horizon is flat, the water is flat, everything looks flat.  However, hour after hour, day after day......I see other big ships coming up over the horizon.  You see the very tops first then more & more of the hulls become visible.  Sometimes whole cities and mountains rise up out of the sea like magic. The same thing is seen on the radars as well.  First you only see just a little single pip once in a while, then slowly more & more return echos hit the screen.  You see this over & over, day after day.  After a while you consult your charts.  Sometimes you do a sighting of a heavenly body and do a little celestial navigation.  The thing here is that all the calculations you do are based upon spherical trigonometry.  All the calculations are based upon the earth being spherical.  Does this conflict with what your eyes actually see?  Yes, some.  What is the unavoidable overall conclusion?  The earth must be spherical.  If you look deep down into the technical operations of the commercial GPS receivers used aboard ships you will see that the software just uses spherical trigonometry to compute your position.  What you used to do by hand now is just done by the computer internal to the GPS receiver.  It's just another indication of the spherical nature of the earth. 

The Zetetic way is for everyone to verify for themselves how things are in the real world.  Don't believe what I've witnessed with my own eyes as evidence of the spherical earth.  Actually do some experiments for yourselves.  Will this probably happen? No.  Most people just don't care enough to spend the time, money, and effort to get it done.  I was lucky. I was trained at a major university as an engineer and got to go to sea and traveled all around the globe for many, many years.  Lots of neat equipment was used to probe the properties of the earth.  When that equipment malfunctioned it was my job to tear into it and get things working again.  To do this the basics of operation had to be understood.  For me it was great fun.  I was doing this kind of thing as a hobby also so often I poked around more than was really necessary just to get a good feeling for how everything really, really worked.  Of course what isn't really well understood is that if you rely on GPS for an accurate position fix you are really just proving to yourself that the earth is a sphere. 

Use the Zetetic method, dig into the actual operation of the GPS for yourself.  If you do sufficient work, you can see the curvature of the earth thru the eyes of the instruments you are working with because you can't see it with your own eyes unless you go into space.
Title: Re: Seeing the curvature of the Earth directly
Post by: robinofloxley on January 11, 2019, 05:17:10 PM
The earth is observably flat by default.

My little finger is observably larger than the tree I can see out of my window, but a bit of logic, education and critical thinking (and a short walk) convinces me that a simplistic "it looks this way, so that's the way it is" is in this case a false conclusion, so objectively I can't always rely simply on what I see.

If I sit in a small boat in the middle of the sea and turn around in a circle, I'll see the horizon at a constant distance away no matter where I look, so from this observation I can perhaps conclude the world is a flat disk maybe 10 miles in diameter. Problem is I move the boat 10 miles away and I'm still in the centre of a circle. This is a puzzle which needs explaining away. I can go down the route of atmospheric effects or perspective or whatever, but from a purely geometric standpoint, me being on top of a very large sphere explains things very easily indeed.

A (large) rotating globe earth provides a very straightforward explanation for all sorts of otherwise awkward to explain observations, It has to be large enough for me not to notice the curvature, sure, but so what, doesn't mean it isn't there. At the other end of the visibility scale, I'm quite convinced there are bacteria and viruses, but I've never personally seen any.
Title: Re: Seeing the curvature of the Earth directly
Post by: Tom Bishop on January 11, 2019, 05:59:47 PM
The earth is observably flat by default.

My little finger is observably larger than the tree I can see out of my window, but a bit of logic, education and critical thinking (and a short walk) convinces me that a simplistic "it looks this way, so that's the way it is" is in this case a false conclusion, so objectively I can't always rely simply on what I see.

An evidence-less argument for an illusion is a weak argument. You need to demonstrate it.
Title: Re: Seeing the curvature of the Earth directly
Post by: inquisitive on January 11, 2019, 06:17:44 PM
The earth is observably flat by default.

My little finger is observably larger than the tree I can see out of my window, but a bit of logic, education and critical thinking (and a short walk) convinces me that a simplistic "it looks this way, so that's the way it is" is in this case a false conclusion, so objectively I can't always rely simply on what I see.

An evidence-less argument for an illusion is a weak argument. You need to demonstrate it.
How would you propose determining the shape and size of the earth?
Title: Re: Seeing the curvature of the Earth directly
Post by: ChrisTP on January 11, 2019, 06:23:47 PM
The earth is observably flat by default.

My little finger is observably larger than the tree I can see out of my window, but a bit of logic, education and critical thinking (and a short walk) convinces me that a simplistic "it looks this way, so that's the way it is" is in this case a false conclusion, so objectively I can't always rely simply on what I see.

An evidence-less argument for an illusion is a weak argument. You need to demonstrate it.
Do you see everything in orthographic? It'll take two seconds to test this yourself with your own finger but sure, no evidence for it. The problem is right in your quote. You refuse to acknowledge any evidence that goes against you for absolutely no reason and then you say no one presents any evidence... And you think we're trying to avoid the topic?

Tom, do you or do you not agree that our visible view on the ground level of the earth would look the same if it were flat or ball?

Now, do you or do you not agree that our own senses can be deceived with optical illusions ?

Now, do you agree that we cannot rely on our own senses for everything, including sight? For example, most people have body dysmorphia, they see their own body completely differently to everyone else. Do you agree with this phenomenon?

Title: Re: Seeing the curvature of the Earth directly
Post by: shootingstar on January 11, 2019, 07:09:03 PM
What I want from the Zetetic side is an example from them of some evidence that applies only if the Earth is flat. They are very good at declaring evidence as meaningless but that is easy to do. Since Tom has already admitted that the Earth looking flat does not prove that it is flat, I want to know what evidence he does accept that convinces him of his convictions.

We are of course as free to discredit his evidence as he is to discredit ours.
Title: Re: Seeing the curvature of the Earth directly
Post by: stack on January 11, 2019, 10:41:59 PM
The earth is observably flat by default. The possibility of it being a big ball, or whatever you imagine it to be, needs to be proven. It simply doesn't matter if you scream "you can't see it because it's an illusion!!1"

I wasn't aware that math is an 'illusion'.
Title: Re: Seeing the curvature of the Earth directly
Post by: robinofloxley on January 11, 2019, 11:03:08 PM
The earth is observably flat by default.

My little finger is observably larger than the tree I can see out of my window, but a bit of logic, education and critical thinking (and a short walk) convinces me that a simplistic "it looks this way, so that's the way it is" is in this case a false conclusion, so objectively I can't always rely simply on what I see.

An evidence-less argument for an illusion is a weak argument. You need to demonstrate it.

My objection is the use of the phrase "by default", implying that without any further evidence, yours is the stronger claim. By the same token I can surely claim my finger is "observably larger than a tree by default". "It looks flat" means nothing to me since I believe this to be indistinguishable from "it looks like a very large globe viewed from on or near the surface".

I quite agree that an argument without evidence is weak, but I don't see that "flat by default" can be taken any more seriously.

For me, a photo from space is compelling (albeit not conclusive) evidence. You will of course dismiss such images as fake, but that inevitably leads us down a rabbit hole of conspiracy that ends up pulling in tens of thousands of people from countries all over the world - something I personally find incredible.

The accepted position in reality is that the earth is a globe. You want to overturn that, fine, in which case, I contend that the burden is on you to convince through evidence. It's the way science works, anyone who challenges the accepted wisdom of the day must necessarily do all the work and provide the necessary evidence to change peoples minds. As an outsider with radical ideas, Einstein would not have got very far by simply asserting Newton was wrong and demanding the establishment provide evidence to the contrary.
Title: Re: Seeing the curvature of the Earth directly
Post by: J-Man on January 12, 2019, 12:33:07 AM
No one is seeing any curvature because it doesn't exist. Lets present the History Channel facts when building the Suez Canal. 120 miles long connecting to different seas with no difference in elevation at opposing ends. In a fake curved earth there should be a 9,600 ft. drop at one sea entrance. That's OVER 1.8 miles of curve. Not there folks, wasn't built for curvature and as History Channel explains "The surveyors’ faulty calculations were enough to scare Napoleon away from the project, and plans for a canal stalled until 1847, when a team of researchers finally confirmed that there was no serious difference in altitude between the Mediterranean and Red Seas."

So please stop the madness, you've been programmed.

https://www.history.com/news/9-fascinating-facts-about-the-suez-canal
Title: Re: Seeing the curvature of the Earth directly
Post by: shootingstar on January 12, 2019, 12:34:46 AM
Quote
The earth is observably flat by default. The possibility of it being a big ball, or whatever you imagine it to be, needs to be proven

Those of the zetitic way of thinking would probably say that only what they believe in can be proven. Their way of dealing with evidence which presents a different way of thinking is to simply overlook it, ignore it or say whatever they deem appropriate in denial. The classic analogy is politicians who are renowned for their abilities to side step a direct question or answer it in a way which makes it sound like they are giving an answer but when you examine the language used you realise they actually haven't.
Title: Re: Seeing the curvature of the Earth directly
Post by: stack on January 12, 2019, 01:15:14 AM
No one is seeing any curvature because it doesn't exist. Lets present the History Channel facts when building the Suez Canal. 120 miles long connecting to different seas with no difference in elevation at opposing ends. In a fake curved earth there should be a 9,600 ft. drop at one sea entrance. That's OVER 1.8 miles of curve. Not there folks, wasn't built for curvature and as History Channel explains "The surveyors’ faulty calculations were enough to scare Napoleon away from the project, and plans for a canal stalled until 1847, when a team of researchers finally confirmed that there was no serious difference in altitude between the Mediterranean and Red Seas."

So please stop the madness, you've been programmed.

https://www.history.com/news/9-fascinating-facts-about-the-suez-canal

Seemingly, you don't know enough about globe earth theory to properly attempt to refute it. You might want to find some other 'evidence' rather than two points 120 miles apart are at the same elevation with a trench inbetween.
Title: Re: Seeing the curvature of the Earth directly
Post by: robinofloxley on January 12, 2019, 08:22:37 AM
No one is seeing any curvature because it doesn't exist. Lets present the History Channel facts when building the Suez Canal. 120 miles long connecting to different seas with no difference in elevation at opposing ends. In a fake curved earth there should be a 9,600 ft. drop at one sea entrance. That's OVER 1.8 miles of curve. Not there folks, wasn't built for curvature and as History Channel explains "The surveyors’ faulty calculations were enough to scare Napoleon away from the project, and plans for a canal stalled until 1847, when a team of researchers finally confirmed that there was no serious difference in altitude between the Mediterranean and Red Seas."

So please stop the madness, you've been programmed.

https://www.history.com/news/9-fascinating-facts-about-the-suez-canal

OK, try this experiment at home. Take a basketball and a sugar cube and a ruler. Place the sugar cube on top of the basketball. Measure the elevation (height) of the sugar cube - about 1cm correct? Now place the sugar cube on the side of the basketball. Measure its elevation - about 1cm right? Or is your definition of elevation somehow different or perhaps your sugar cube mysteriously grows when you move it.
Title: Re: Seeing the curvature of the Earth directly
Post by: J-Man on January 12, 2019, 03:44:46 PM
No one is seeing any curvature because it doesn't exist. Lets present the History Channel facts when building the Suez Canal. 120 miles long connecting to different seas with no difference in elevation at opposing ends. In a fake curved earth there should be a 9,600 ft. drop at one sea entrance. That's OVER 1.8 miles of curve. Not there folks, wasn't built for curvature and as History Channel explains "The surveyors’ faulty calculations were enough to scare Napoleon away from the project, and plans for a canal stalled until 1847, when a team of researchers finally confirmed that there was no serious difference in altitude between the Mediterranean and Red Seas."

So please stop the madness, you've been programmed.

https://www.history.com/news/9-fascinating-facts-about-the-suez-canal

OK, try this experiment at home. Take a basketball and a sugar cube and a ruler. Place the sugar cube on top of the basketball. Measure the elevation (height) of the sugar cube - about 1cm correct? Now place the sugar cube on the side of the basketball. Measure its elevation - about 1cm right? Or is your definition of elevation somehow different or perhaps your sugar cube mysteriously grows when you move it.

As a licensed builder you might want to take that stupid idea once step further. Since we are talking about building a 120 mile long canal based on a datum line.

NOW take a string of dental floss and stretch it tightly from the two sugary cubes. Bummer fricking basketball in the way to get a straight plum line. Learn to read the article, learn a trade, something as simple as masonry where string lines are mandatory with levels.
Title: Re: Seeing the curvature of the Earth directly
Post by: RonJ on January 12, 2019, 04:42:39 PM
Anyone who believes that the Suez Canal can only happen on a flat earth doesn't really understand the way water really works.  I've actually been thru the Suez canal countless times, in both directions.  I always observe sea level on both sides.  What is meant by sea level is just the distance between the surface of the ocean and the center of the spherical earth.  As long as that distance is identical at each point along the canal, no water will flow. 

It seems that the flat earth people are always is confused with exactly what 'down hill' really means. Where water is concerned, 'down hill' means a lessening of the distance between any drop of water and the center of the earth.  As long as that 'center distance' is the same at all points no water will flow. 

I did go to school and I did learn a trade.  We learned about pumps, pipes, nozzles, and lots of other interesting stuff.  There were also some lessons about the properties of water.  In one of those lessons I learned that water will always flow in the direction of the net force vector.  You can have water sit nice and flat and not flow on the surface of a spherical earth as long as the distance between the water's surface and the center of the earth is the same at all points along the way. 

If you want to do a Zetetic experiment look at the elevation of the head of any river, like the Mississippi River, and the elevation at the mouth.  You will always find that the distance between the start of the river and the center of the earth is a bit longer than at the end of the river.  Water in the river will ALWAYS flow to a spot closer to the center of the earth as long as there are no other external forces involved, like hurricanes, or tides. 

If you don't believe that, then just cite an example where water flows in some other direction than the net applied force vector.  If you can't find a valid example, then you have to believe that the earth really could be spherical even after observing what is happening on the Suez Canal.
Title: Re: Seeing the curvature of the Earth directly
Post by: robinofloxley on January 12, 2019, 06:35:06 PM
No one is seeing any curvature because it doesn't exist. Lets present the History Channel facts when building the Suez Canal. 120 miles long connecting to different seas with no difference in elevation at opposing ends. In a fake curved earth there should be a 9,600 ft. drop at one sea entrance. That's OVER 1.8 miles of curve. Not there folks, wasn't built for curvature and as History Channel explains "The surveyors’ faulty calculations were enough to scare Napoleon away from the project, and plans for a canal stalled until 1847, when a team of researchers finally confirmed that there was no serious difference in altitude between the Mediterranean and Red Seas."

So please stop the madness, you've been programmed.

https://www.history.com/news/9-fascinating-facts-about-the-suez-canal

OK, try this experiment at home. Take a basketball and a sugar cube and a ruler. Place the sugar cube on top of the basketball. Measure the elevation (height) of the sugar cube - about 1cm correct? Now place the sugar cube on the side of the basketball. Measure its elevation - about 1cm right? Or is your definition of elevation somehow different or perhaps your sugar cube mysteriously grows when you move it.

As a licensed builder you might want to take that stupid idea once step further. Since we are talking about building a 120 mile long canal based on a datum line.

NOW take a string of dental floss and stretch it tightly from the two sugary cubes. Bummer fricking basketball in the way to get a straight plum line. Learn to read the article, learn a trade, something as simple as masonry where string lines are mandatory with levels.

Absolutely agree, the basketball is getting in the way. Let's scale that up, so try stretching 10,000km of dental floss between two tall towers and you are going to find the fricking earth getting in the way too.

Your argument is that one part of the canal is 9,600 ft lower than the other. But which end is it then? The question is meaningless on a globe - take a picture of a basketball against a plain background and tell me where the top is. Depends entirely on the orientation of the camera. A sphere on its own without reference to something doesn't have a top or a bottom so there is no lower or higher either. Sure, through an accident of history, if you buy a standard globe and put it on a desk, the northern hemisphere is "above" the southern with respect to the desk, but buy a dual axis globe and you can turn it around to put Australia on top if you like. Just as valid.

So take your dual axis globe, turn it around so the Western end of the canal is on top and the Eastern end is "lower" (simply meaning nearer the desk), now adjust it so the Eastern end of the canal is at the top. Hey presto the Western end is "lower". Both perfectly valid viewpoints, but meaningless since there is no external reference point to determine which hemisphere is up and which is down.
Title: Re: Seeing the curvature of the Earth directly
Post by: RonJ on January 14, 2019, 04:35:39 AM
I saw a nice program on the Apollo 8 mission.  The idea was to navigate to the moon, orbit and come back without landing.  In order to navigate a sextant was installed so the earth & a navigational star could be observed and the spacecraft could be properly positioned along the route.  The black & white image on the lower right shows a nice view of the earth.  Even if the lens was dubbed as a 'fish eye' it wouldn't matter.  You can see the whole globe.
 
https://space.stackexchange.com/questions/24619/was-the-apollo-sextant-used-or-tested-to-determine-position-while-in-earth-orb

I believe that the whole series of photographs of the periscope view is available on PeriscopeFile.com

Is this another example of the NASA lies?  If that's not the case then you will have to disbelieve your eyes as the pictures clearly show the form of the earth.
 
Title: Re: Seeing the curvature of the Earth directly
Post by: Bad Puppy on January 14, 2019, 07:39:38 PM
The earth is observably flat by default.

No. Objects don't have a default shape, smell, colour, or anything.  The an observer of an object will define its properties through observation, measurement, or other means of identification.  If any properties an object are later learned to be incorrect, usually due to advances in science, then those properties are redefined.

Like, the earth was observed to be flat.  Then we went to space and saw that it's not flat, and instead is actually an oblate spheroid.
Title: Re: Seeing the curvature of the Earth directly
Post by: RonJ on January 14, 2019, 08:03:33 PM
I agree that it is difficult to actually see the earth's curvature by looking at the horizon.  The 'sinking ship' effect seems to be somewhat controversial on this site.  Why not just short circuit that whole argument and look at something in the sky, the North Star for example?

https://forum.tfes.org/index.php?topic=9797.msg175959#msg175959

When you look at this post you will see that the mathematics just won't work out unless the earth is spherical.  This is a direct observation of the curvature of the earth by observing something above the earth and not on the earth. 
Title: Re: Seeing the curvature of the Earth directly
Post by: AATW on January 14, 2019, 09:47:26 PM
Like, the earth was observed to be flat.  Then we went to space and saw that it's not flat, and instead is actually an oblate spheroid.
We'd actually, as a species, long since worked that out.
But yes, since the late 1940's when we've had rocket technology we have been able to confirm it with observations were there any lingering doubt.
That should have killed the flat earth theories stone dead but in a fit of cognitive dissonance which psychologists could write entire books about they just declared every single photo and video from space from every country fake.
Title: Re: Seeing the curvature of the Earth directly
Post by: SurroundedByGenius on January 16, 2019, 07:38:16 PM
Any footage taken from an SR-71 or U-2, the thousands of pictures/video taken from space, that directTV channel that shows the planet we live on spinning, seeing the top of a ship on the horizon before the entirety of the ship, actually SEEING the curvature at sea. All evidence to the contrary of your theory. If you try to shoot something from a mile away, why does the bullet veer left or right in a predictable manner(depending on the direction you are facing when the bullet leaves the muzzle)?That’s the Coriolis effect, and any combat sniper can tell you it’s real. That’s just a start and anyone with common sense and a functioning brain would see that’s an awful lot of covering up by a lot of people(as I’m sure that will be your defense) to accomplish nothing more than proving your theory wrong.
Title: Re: Seeing the curvature of the Earth directly
Post by: Max_Almond on January 22, 2019, 10:53:00 AM
You can see the curvature of the Earth directly in a number of ways. One would be to gain some altitude, such as in an aeroplane, as demonstrated in this photo from just over 46,000 feet:

(https://www.metabunk.org/attachments/screenshot-2-png.35493/)

Another method would be to climb a hill of at least 500 feet overlooking the sea, take a photo of a nice clear horizon, and then when you get home stretch it vertically. Straight lines stay straight, while curved lines are exaggerated, like this:

(https://www.metabunk.org/data/MetaMirrorCache/7a8815d494db19c3d3755795ab8f77cf.jpg)

Vertically stretched/horizontally compressed, centred on horizon:

(https://www.metabunk.org/attachments/20160813-094442-nnkgz-jpg.20595/)

Note: when taking photos like this, great care must be taken to ensure that lens distortion is not creating or exaggerating the curve of the horizon. There are different ways this can be done.

Both of the above examples of 'directly seeing the Earth's curvature' can be checked against a mathematical model at walter.bislins.ch (http://walter.bislins.ch), as well as compared with what these views would look like on a flat earth.
Title: Re: Seeing the curvature of the Earth directly
Post by: Physical_Copy on January 22, 2019, 01:29:20 PM
The onus is with FE.  It is their responsibility to prove the earth is flat, not the other way around.  The reason is that mainstream scientific opinion-- a theory you must admit was successful in its own right-- was well established for centuries before the FE community dissented.  There is no "default assumption" about the shape of the earth; various indigenous cultures also assumed the earth was infinite, round, in the branches of a giant tree, hatched from an egg laid by a giant primordial bird, one world of many, sentient and good, sentient and evil, etc.  If you think the world is flat you must provide evidence toward that end; the globe-earthers already did that for their theory.  The FE community obviously thinks that evidence isn't very good, but objectively they have no analogous model which matches the predictive power and real-world fidelity of the globe earth theory.  GE theory is robust, ancient, and supported by copious evidence-- you can't just dismiss it out of hand.  Build a better theory and I'll listen.
Title: Re: Seeing the curvature of the Earth directly
Post by: inquisitive on January 22, 2019, 09:31:53 PM
The earth is observably flat by default. The possibility of it being a big ball, or whatever you imagine it to be, needs to be proven. It simply doesn't matter if you scream "you can't see it because it's an illusion!!1"

The fact that when we look at the matter closer and we find contradicting observations into the distance which support sinking and non-sinking is pretty telling. The fact that we have seen multiple long term timelapse of the horizon (https://wiki.tfes.org/Sinking_Ship_Effect_Caused_By_Refraction) which show that the light is constantly curving in the distance to make things appear to sink, and sometimes to unsink, is also telling. The fact that the famous sinking photos don't even match up with the stated curvature for the round earth, which we have looked at, is telling still.

There is no real evidence for the ball earth. Aristotile's proofs for a globe based on sinking ships and lunar eclipses are unsupportable.
It is proven every day by measured distances, the path of the sun and satellite operation.

It is strange that you choose to claim otherwise and have not performed any measurements, or so you say.
Title: Re: Seeing the curvature of the Earth directly
Post by: iamcpc on January 22, 2019, 09:57:27 PM
You can see the curvature of the Earth directly in a number of ways. One would be to gain some altitude, such as in an aeroplane, as demonstrated in this photo from just over 46,000 feet:

Here's one that i thought was curious:

https://www.youtube.com/watch?v=A0bwlQMch3s

I know there are a lot of doubts around NASA. What about the mythbusters?
Title: Re: Seeing the curvature of the Earth directly
Post by: Max_Almond on January 23, 2019, 08:48:44 AM
I wish they'd used a better camera in this, instead of the all-distorting fish eye.
Title: Re: Seeing the curvature of the Earth directly
Post by: shootingstar on January 23, 2019, 11:13:44 AM
Here's James May doing the same thing (lucky so and so...)

https://www.youtube.com/watch?v=1PmYItnlY5M
Title: Re: Seeing the curvature of the Earth directly
Post by: Max_Almond on January 23, 2019, 01:59:44 PM
If you go to walter.bislins.ch you can find a simulated view of what the horizon would look like on either the flat earth or globe earth model and see which one matches what we see from a given elevation. Assuming a non-distorting camera, of course. :)
Title: Re: Seeing the curvature of the Earth directly
Post by: TomFoolery on February 11, 2019, 04:45:58 AM
...
Another method would be to climb a hill of at least 500 feet overlooking the sea, take a photo of a nice clear horizon, and then when you get home stretch it vertically. Straight lines stay straight, while curved lines are exaggerated, like this:

Note: when taking photos like this, great care must be taken to ensure that barrel distortion is not creating or exaggerating the curve of the horizon. There are different ways this can be done.
pared with what these views would look like on a flat earth.

So about barrel distortion, it curves straight lines around the center of the picture.
So you'd want to take two photos - one with the horizon slightly above the center of the picture, and the other with it slightly below.

Stretch them both equally, and take note - if they both curve the same way, then it's curve of the horizon.
However, if one curves up and the other curves down, then you're mostly seeing barrel distortion.

In reality, even with a curved earth if such were the case, you would probably see a combination of curve plus barrel disortion, so the photo with the horizon above center would show more curve and the other would show less curve or straight, or a negative curve, but not as much of a curve as the above-center horizon photo.

That's what's tricky about gopro fighter jet flight videos - even the default lenses have some barrel distortion and you can see that the horizon bulges up if it's above center, and sags down (concave) when it's below center of picture. You'd have to freeze frame the video right when the horizon line was in center of the picture, and see if it showed curve at that point. But even then, many early gopros had rolling shutter which can create rolling wave patterns in the picture so even if you saw a curve in the center of the picture it could be from the vibration of the jet and the rolling shutter.

What you'd really want to do is go up to a high point, and stretch a thin black string super tight between two trees. Maybe tie a couple helium balloons to it for good measure so it can't sag down.
Then step back move your camera so the string lines up with the horizon, and take a picture. That way you're comparing the horizon to a known straight line before it enters the camera's optics and gets distorted. That way, if the optics curves the horizon, it'll also curve the string equally.

If that showed a curve, ok now you'd have my attention. Just make sure the string is super tight, because if it sags down it'll make the earth look like it's curved up.
That's why the helium balloons to guarantee that if the string is curved at all, it's up. Then if the earth curves above that,  we know we got something. But don't worry, nobody's tried this yet. When they do, we can see that it's as flat as a pancake. Flatter, actually. I plan to try it myself when the snow melts in the mountains.
Title: Re: Seeing the curvature of the Earth directly
Post by: TomFoolery on February 11, 2019, 04:52:20 AM
The earth is observably flat by default. The possibility of it being a big ball, or whatever you imagine it to be, needs to be proven. It simply doesn't matter if you scream "you can't see it because it's an illusion!!1"

The fact that when we look at the matter closer and we find contradicting observations into the distance which support sinking and non-sinking is pretty telling. The fact that we have seen multiple long term timelapse of the horizon (https://wiki.tfes.org/Sinking_Ship_Effect_Caused_By_Refraction) which show that the light is constantly curving in the distance to make things appear to sink, and sometimes to unsink, is also telling. The fact that the famous sinking photos don't even match up with the stated curvature for the round earth, which we have looked at, is telling still.

There is no real evidence for the ball earth. Aristotile's proofs for a globe based on sinking ships and lunar eclipses are unsupportable.

Tom, Greetings.

What do you think about a theodolite? They seem really cool and people seem to mention them.
Could they be used to check the angular height of distant mountains, and confirm or deny a curve?

Basically it'd be a cinch. Just set up the theodolite and measure the angular height of a distant mountain of a known height and distance.
The theodolite gives you the angle above eyelevel in degrees, and you just feed that into tanget() and multiply that times the distance and that gives you the height.
Naturally you'd want to compensate for your observer elevation and perhaps for terrestrial atmospheric refraction which is supposed to be one degree for every 932 miles.

Would you consider this strong evidence either way?
Title: Re: Seeing the curvature of the Earth directly
Post by: Max_Almond on February 11, 2019, 06:09:14 AM
So about barrel distortion, it curves straight lines around the center of the picture.

In reality, you would probably see a combination of curve plus barrel disortion, so the photo with the horizon above center would show more curve and the other would show less curve or straight, or a negative curve, but not as much of a curve as the above-center horizon photo.

One thing you can do is take a photo of a grid and analyse that. On my iPhone SE the lines about 109 pixels above and below the centre of the frame were straight, and the ones after that began to curve. That gives me a 218 pixel 'sweet spot', and the horizon occupies only about 10% of that.

Here's a compressed image of the grid:

(https://www.metabunk.org/attachments/iphone-se-test-jpg.35836/)

And here's a picture of the horizon I took, with the mathematical prediction overlayed:

(https://www.metabunk.org/attachments/bislin-sa-talaia-gif.35843/)

Next time I'm going to photograph the horizon with some straight metal bars placed just above and just below it, which I figure is the best demonstration that barrel distortion isn't causing the curve.

Cheers. :)
Title: Re: Seeing the curvature of the Earth directly
Post by: TomFoolery on February 11, 2019, 04:51:03 PM
Next time I'm going to photograph the horizon with some straight metal bars placed just above and just below it, which I figure is the best demonstration that barrel distortion isn't causing the curve.

Cheers. :)

Ack, that flashing is annoying  ;D

But instead of using metal bars, how about a super tight string with a few helium balloons tied to it around the middle so we know it's not sagging down causing a false appearance of comparative curve?

Your metal bars might not be straight, or might be sagging under their own weight, causing a false appearance of upward earth curve.
Title: Re: Seeing the curvature of the Earth directly
Post by: ChrisTP on February 11, 2019, 05:03:37 PM
String with balloons attached may also make a string curve upward though. A solid metal that doesn't bend easy would be fine imo.
Title: Re: Seeing the curvature of the Earth directly
Post by: Max_Almond on February 11, 2019, 05:11:15 PM
It's probably easier to show that the metal bars are straight, since I've seen that the camera doesn't distort in the centre 7% and the bars aren't heavy enough to bend under their own weight.
Title: Re: Seeing the curvature of the Earth directly
Post by: TomFoolery on February 11, 2019, 07:15:00 PM
String with balloons attached may also make a string curve upward though. A solid metal that doesn't bend easy would be fine imo.

But a glober might not believe that the metal bars are straight. A tight string has to be very close to straight, and if it curves, its a simple matter to know which way it's curving.

Without the balloons, a some of your fellow flat earthers might say that it was just sagging and the apparent upward bulge of the horizon was just by comparison to the sagging string, which is why the balloons are important - *if* there was any measurable sag, it would be up, not down, so it makes the experiment rather bulletproof.

However we could always try the straight metal edges, and if that showed a curve then some are going doubt it, and then we can try with a tight string, and if that still shows a curve then we can try the tight string with the balloons and well then the horizon can't be curved.

One advantage of the string is that if it will be a lot easier to set up a perfectly straight 10 ft string up in the mountains as compared to trying to hike up a 10 ft metal  bar and keeping it straight.  And the reason it's important for it to be long is so you can have it go all the way across your field of view while still being some distance from the camera so that it can be in focus as well as the horizon being in focus. If the bar is too close to the camera, either it or the horizon will be blurry and it'll blur the issue.

Another advantage of the string is that it won't block the view above or blow itself like the metal bar will.

As you can tell, I'm very excited to get up in the mountains with some string and balloons, but at the moment we got record snows here and I need chains just to get to the grocery store so there's no mountain trips for me for a while.
Title: Re: Seeing the curvature of the Earth directly
Post by: Tom Bishop on February 11, 2019, 09:15:02 PM
So about barrel distortion, it curves straight lines around the center of the picture.

In reality, you would probably see a combination of curve plus barrel disortion, so the photo with the horizon above center would show more curve and the other would show less curve or straight, or a negative curve, but not as much of a curve as the above-center horizon photo.

One thing you can do is take a photo of a grid and analyse that. On my iPhone SE the lines about 109 pixels above and below the centre of the frame were straight, and the ones after that began to curve. That gives me a 218 pixel 'sweet spot', and the horizon occupies only about 10% of that.

Here's a compressed image of the grid:

(https://www.metabunk.org/attachments/iphone-se-test-jpg.35836/)

And here's a picture of the horizon I took, with the mathematical prediction overlayed:

(https://www.metabunk.org/attachments/bislin-sa-talaia-gif.35843/)

Next time I'm going to photograph the horizon with some straight metal bars placed just above and just below it, which I figure is the best demonstration that barrel distortion isn't causing the curve.

Cheers. :)

All cameras are affected by some amount of barrel distortion. An absurd test.

(https://i.imgur.com/m5MsHAY.jpg)

Compressed with your methods, compressing the width to 500 and stretching the height to 3000:

(https://i.imgur.com/3itCvu3.jpg)

I guess the earth must be concave?
Title: Re: Seeing the curvature of the Earth directly
Post by: stack on February 11, 2019, 11:51:46 PM
All cameras are affected by some amount of barrel distortion. An absurd test.

Yes, all lenses suffer some level of barrel distortion. However, when you go above 50mm the distortion levels get smaller and smaller to almost nil.

As well, you can pop into something like photoshop and specifically correct barrel distortion. Some cameras these days even let you correct for a specific lens in-camera.

And there are all kinds of tutorials and software around to 'de-fisheye' GoPro footage in Post.
Title: Re: Seeing the curvature of the Earth directly
Post by: Max_Almond on February 12, 2019, 05:33:00 AM
What camera was that photo taken with, Tom? Was the horizon centred in the frame? How does its distortion look when tested with a grid?

My suspicion is that you didn't take this photo, and that you purposefully chose one with a horizon located well below the centre of the frame, which we all know will significantly distort.

That aside, how about you go and do the test yourself? Do you have a camera? Can you find a place to photograph the horizon from above 400 feet?

If so, take the photo with the horizon perfectly centred, then do the vertical stretch and see what it shows. Then take a photo of a grid, such as this one (https://www.metabunk.org/attachments/grid-png.27560/), and do the same thing, to see how your camera is distorting.

Then compare the two images and also compare your stretched photo with the mathematical prediction for both flat earth and globe earth models.

Pure zeteticism. What possible reason could there be not to do it?
Title: Re: Seeing the curvature of the Earth directly
Post by: BillO on February 12, 2019, 02:22:51 PM
I guess the earth must be concave?  ::)
Tom, the image you selected is clearly not suitable for the suggested experiment as the horizon is well below the center of the image.  This should be obvious, especially if barrel distortion is suspected as was evidenced from your first comment.  Or do you really not know how optics work?  It is also obvious you did some other manipulation to the image too, making your result suspect.

For this experiment to work effectively, the horizon line must pass through the center of the lens to eliminate the effects of barrel or pincushion distortion.
Title: Re: Seeing the curvature of the Earth directly
Post by: Bad Puppy on February 12, 2019, 09:33:30 PM
Here you go Tom.  Do a bit of light reading.

https://lenspire.zeiss.com/photo/en/article/curved-images-of-straight-lines-what-is-distortion (https://lenspire.zeiss.com/photo/en/article/curved-images-of-straight-lines-what-is-distortion)

Congratulations.  You've just proved yourself to be completely unqualified to offer any credible analysis on photography.
Title: Re: Seeing the curvature of the Earth directly
Post by: Tom Bishop on February 13, 2019, 03:32:11 AM
I posted it as an example of distortion. Learn to read.
Title: Re: Seeing the curvature of the Earth directly
Post by: BillO on February 13, 2019, 04:24:08 AM
I posted it as an example of distortion. Learn to read.
Wonderful!  Not really stated as claimed, but quite demonstrative nonetheless ... and unfortunately a bit off topic as a result.

Now it would be great if you did the experiment correctly.

I'm currently vacationing in southern Florida, so I'll endeavor to attempt it over the next few days.

For lenses I have at my disposal both a Pentax FA* 24mm F2 and a Pentax FA 50mm F1.4 which are considered to be above average for these focal lengths in barrel distortion (See links below).  However, I will be using an APS sized sensor camera body (Pentax K3 II) ensuring only the sweet-spot of each lens will be used to form the image.  Of course the horizon will be placed directly at the vertical center of the image where any such distortion should be eliminated.  I will use Photoshop to do the transformations.  I will make the raw jpeg images available to anyone who wishes them.

Tom?


https://www.opticallimits.com/pentax/121-pentax-smc-fa-24mm-f2-al-if-review--lab-test-report?start=1 (https://www.opticallimits.com/pentax/121-pentax-smc-fa-24mm-f2-al-if-review--lab-test-report?start=1)

https://www.opticallimits.com/pentax/126-pentax-smc-fa-50mm-f14-review--lab-test-report?start=1 (https://www.opticallimits.com/pentax/126-pentax-smc-fa-50mm-f14-review--lab-test-report?start=1)
Title: Re: Seeing the curvature of the Earth directly
Post by: Max_Almond on February 13, 2019, 06:05:30 AM
That sounds very good. You could also take a photo of this grid, and make that available for us to analyse:

(https://www.metabunk.org/attachments/grid-png.27560/)
Title: Re: Seeing the curvature of the Earth directly
Post by: BillO on February 13, 2019, 12:54:37 PM
Max, there are grid shots from the tests of these lenses at those links I provided.  Do you still want me to provide more?
Title: Re: Seeing the curvature of the Earth directly
Post by: Max_Almond on February 13, 2019, 02:25:03 PM
Thanks. I've clicked on the links now. :)

The grid above might be better though, or one similar. The more lines, the easier it is to see where distortion is present, and where the lens is shooting true. Plus, it'll show us your actual personal lens, which is a bonus.

In the meantime, I've knocked up a little frame with some bits I found lying round:

(https://www.metabunk.org/attachments/horizonamotic5000-jpg.36073/)

The ties are to squeeze it together a little to get the two edges as straight and parallel as possible. I've a little more work to do on it but the results are pretty nice:

(https://www.metabunk.org/attachments/horizonamotic5000_squashed-jpg.36074/)

As we can see, the two edges close to the centre remain pretty much straight, while the ones above and below reveal significant pincushion distortion.

Locate the horizon in the very centre of the image, between the two straight edges, and we can show that it retains its shape, which is a curve.

I'll be trying it out soon, from the 1500 foot hill nearby.
Title: Re: Seeing the curvature of the Earth directly
Post by: BillO on February 13, 2019, 07:54:07 PM
Here are the grid images for the 24mm lens.  I'm vacationing so could only take a picture of my laptop screen, hence it was difficult to keep things perfectly aligned.  However, it is clear that the center is not affected by any barrel/pincushion distortion, although I got a little slant on it.

Title: Re: Seeing the curvature of the Earth directly
Post by: BillO on February 13, 2019, 07:56:33 PM
Here is the same for the 50mm lens.  A bit better.

If anyone wants the raw files, just PM me an email address I can send them to.
Title: Re: Seeing the curvature of the Earth directly
Post by: TomFoolery on February 14, 2019, 05:25:28 AM
<snip>
All cameras are affected by some amount of barrel distortion. An absurd test.

Hmm, what if we used a pinhole on the camera instead of a lens? Would that eliminate the barrel distortion?
(I'm talking about like a DSLR here with a removable lens.)
Title: Re: Seeing the curvature of the Earth directly
Post by: Max_Almond on February 14, 2019, 05:37:53 AM
However, it is clear that the center is not affected by any barrel/pincushion distortion, although I got a little slant on it.

Nice one Bill, thanks for posting those.

The slant is actually the hardest bit of it, for me. What looks level to the eye can be massively slanted when stretched/compressed.

When I take the picture with the (levelled) metal frame I'll measure from camera to each edge, and hope that sorts it out.

Hmm, what if we used a pinhole on the camera instead of a lens? Would that eliminate the barrel distortion?

Yes. But, at the same time, as long as Bill gets it near the middle of the frame it's clear his lens isn't going to make straight lines curved.

I wonder where he'll be in Florida that'll give him 400 feet or more elevation?
Title: Re: Seeing the curvature of the Earth directly
Post by: BillO on February 14, 2019, 06:51:47 PM
I wonder where he'll be in Florida that'll give him 400 feet or more elevation?
Why do you need the elevation?

Edit:  Never mind - just had to kick my brain into gear.  Well, that presents a problem.  I guess I could go looking for a tall building I could get up on, but other than that, I am SOL.  I'm still hear for another 2 weeks so maybe I'll find a solution.
Title: Re: Seeing the curvature of the Earth directly
Post by: Max_Almond on February 14, 2019, 08:44:21 PM
You can use Walter Bislin's very excellent globe earth/flat earth simulator (http://walter.bislins.ch/bloge/index.asp?page=Flat-Earth%3A+Finding+the+curvature+of+the+Earth) to see what the horizon would look like from a given altitude and field of view.

The attachments show what the horizon would look like for the two lenses from 328 feet. It's not a massive curve from that altitude, hence why even more is better.
Title: Re: Seeing the curvature of the Earth directly
Post by: Max_Almond on March 16, 2019, 11:36:02 AM
I would like to give some credit here to Samuel Rowbotham, for in one of his proposed experiments he said that a straight edge held up to the horizon should reveal curvature if the earth is a globe, and that the horizon should stay straight if the earth is flat.

Unfortunately, back in his day, he didn't have the technology to carry out this experiment, but now we can. Here are some photos of a straight edge not only placed right beneath the horizon, but above it too:

(https://www.metabunk.org/attachments/img_1968-jpg.36580/)

And here is that image vertically stretched, showing that the curve of the horizon isn't being caused by lens distortion:

(https://www.metabunk.org/attachments/img_1968-jpg.36537/)
Title: Re: Seeing the curvature of the Earth directly
Post by: QED on March 16, 2019, 02:57:35 PM
I would like to give some credit here to Samuel Rowbotham, for in one of his proposed experiments he said that a straight edge held up to the horizon should reveal curvature if the earth is a globe, and that the horizon should stay straight if the earth is flat.

Unfortunately, back in his day, he didn't have the technology to carry out this experiment, but now we can. Here are some photos of a straight edge not only placed right beneath the horizon, but above it too:

(https://www.metabunk.org/attachments/img_1968-jpg.36580/)

And here is that image vertically stretched, showing that the curve of the horizon isn't being caused by lens distortion:

(https://www.metabunk.org/attachments/img_1968-jpg.36537/)

Hmm,  this is such an easy test to make. Is there any way the process of vertically stretching it has distorted the image to produce artificial curvature? I mean, there really is no point of having the bars there, one could just take a digital image of a sea-line, and provided it encloses enough distance, a vertical stretching should demonstrate the truth of this alone.

Can others verify/dispute this result?
Title: Re: Seeing the curvature of the Earth directly
Post by: Matthew7 on March 16, 2019, 09:10:40 PM
I think the point of the bars is that (especially given that barrel distortion becomes stronger towards the upper and lower limits of the image, as discussed above) they provide evidence that the curve of the horizon  between the bars cannot be due to a distortion from the lens, or during processing: If the actual image were put down distorted on the imaging surface of the camera the bars would also be distorted, and if the grid underlying the image had been distorted in such a way as to cause the curve the upper and lower bars would be distorted too. I'm not an imaging expert so I can't say if this is a perfect test, but it certainly seems simple, well thought out and ingenious.
Title: Re: Seeing the curvature of the Earth directly
Post by: Tom Bishop on March 17, 2019, 12:59:51 AM
The author tells us that it took over 400 photos to get the one that he wanted (http://archive.fo/57WTh):

"In all the images I took today - there were over 400 in total"

He goes on to tell us that the horizon was curved and the beams were straight in the remainder of the 400 photos that he does not show us:

"the curve of the horizon shows the same, while the straight edges stay straight."

However, of the couple of photos he shows us, the curvature of the beams are inconsistent:

Straight:

(https://i.imgur.com/ZTkGedI.jpg)

Then the author shows us a version with the beams tilted in comparison with the horizon. In this one we can see that there is clearly curvature on the beams:

(https://i.imgur.com/UNPWzhY.png)


I bet that if I took over 400 photos of distortion, I could eventually get what I wanted too.
Title: Re: Seeing the curvature of the Earth directly
Post by: Jeppspace on March 17, 2019, 01:46:38 AM
Thanks Tom.

Also, whilst the horizon is straight, there will certainly be more heaving or movement of water towards the center than towards the shore. Indeed perhaps more waves.

When stretching these, as such amplifying the micro features of unevenness,  it may present such an illusion, particularly as Tom Bishop demonstrates, whence the distortion is quite rogue.

400 shots? Was he comparing waves?

Finally, the meeting of the two blues, sky and sea, when stretched in this way, may produce just enough morphing at the horizon to contribute to a misrepresentation, especially if there are much more prominent waves towards the center.

Indeed a dynamically living feature, such as a mass of moving water, is perhaps not the ideal subject to feature in this experiment.

Since computers only work from code and not real world senses, all these factors may create an artificial perspective.
Title: Re: Seeing the curvature of the Earth directly
Post by: QED on March 17, 2019, 02:38:05 AM
The author tells us that it took over 400 photos to get the one that he wanted (http://archive.fo/57WTh):

"In all the images I took today - there were over 400 in total"

He goes on to tell us that the horizon was curved and the beams were straight in the remainder of the 400 photos that he does not show us:

"the curve of the horizon shows the same, while the straight edges stay straight."

However, of the couple of photos he shows us, the curvature of the beams are inconsistent:

Straight:

(https://i.imgur.com/ZTkGedI.jpg)

Then the author shows us a version with the beams tilted in comparison with the horizon. In this one we can see that there is clearly curvature on the beams:

(https://i.imgur.com/UNPWzhY.png)


I bet that if I took over 400 photos of distortion, I could eventually get what I wanted too.

I agree with your skepticism 100%. A scientist shows all data, not the one data point that fits the sought result.

I encourage all forum users who live by coasts to report their photos. One does not need the beams, vertical scaling should show whether the curvature exists or not.

Is it possible to build a repository for such data on this cite?
Title: Re: Seeing the curvature of the Earth directly
Post by: Max_Almond on March 17, 2019, 05:46:33 AM
Is there any way the process of vertically stretching it has distorted the image to produce artificial curvature?

No. The curve is evident even before vertically stretching - you can zoom in on the image and note that the pixel height is lower at the edges of the curve than in the centre. Stretching just makes it more obvious.

I think the point of the bars is that (especially given that barrel distortion becomes stronger towards the upper and lower limits of the image, as discussed above) they provide evidence that the curve of the horizon between the bars cannot be due to a distortion from the lens, or during processing.

Exactly. Well-centred photos of the horizon also show a pronounced curve, the bars are merely there to show the hyperskeptical that the curve isn't produced by barrel, pincushion, or moustache distortion.

The author tells us that it took over 400 photos to get the one that he wanted. (http://archive.fo/57WTh)

Nice attempt to lie and cherry pick, Tom. The 'author' actually tells us that he took over 400 photos and the curve was always the same.

I'm sure if you wanted to see all 400+ photos you could just ask him and he'd be happy to show you. He seems like the kind of guy to back up his experiments and assertions with evidence and reasonableness, unlike some. You might be able to learn a thing or two from him.

I do hope Tom's followers, if there are any, are picking up on this.
Title: Re: Seeing the curvature of the Earth directly
Post by: WellRoundedIndividual on March 17, 2019, 12:12:55 PM
Yes, this is literally what he says:

"In all the images I took today - there were over 400 in total - the curve of the horizon shows the same, while the straight edges stay straight.

The curve matches both the simulated curve from Walter Bislin's website and the expected pixel difference between the centre of the curve and the edge (~4).
Rory, Thursday at 4:01 PM #39"

So, Tom Bishop is a liar.
Title: Re: Seeing the curvature of the Earth directly
Post by: QED on March 17, 2019, 02:11:52 PM
I would like to see this independently verified/disputed by folks on here who live on coasts. It is an easy measurement to take, and this would permit independent sources to weigh in.

Whether you are a FEer or REer, this type of test is your honey pot. If you want to see the truth for yourself, that is.

I am quite curious what folks will find, and would be snapping photos right now if I wasn’t smack dab in the middle of the country.
Title: Re: Seeing the curvature of the Earth directly
Post by: manicminer on March 17, 2019, 02:25:57 PM
From the same article I note it says this...

Quote
It looks flat, and in fact the horizon IS geometrically flat. Since all the points on the ocean horizon are the same distance away from you, and the same distance below you, the horizon forms a flat circle with its center some distance below your feet.

And I do believe I have pointed this out before, for the very same reason that the photographer state.  So how does a flat horizon prove a flat Earth? 

The photographer also points out correctly that the curvature will only become apparent once you gain enough height.  You need to be able to see enough of the surface area of the Earth before the curve becomes directly apparent.  I made reference to that in the last paragraph of my opening post for this thread.   The photos shown in the posts above will never show any hint of curvature.
Title: Re: Seeing the curvature of the Earth directly
Post by: Jeppspace on March 17, 2019, 04:06:42 PM
(https://i.ibb.co/tx1GRBH/2019-03-17-041917.png) (https://imgbb.com/)
Title: Re: Seeing the curvature of the Earth directly
Post by: Max_Almond on March 17, 2019, 07:55:31 PM
The edges you need to consider are the ones above and below the horizon, and independently, since they're not connected.

Also, there's no reason to draw horizontal lines, but rather lines across the edges.

Here's another one, where the edges have been angled upwards in opposition to the curve:

(https://i.imgur.com/dZsevkR.jpg)

It all seems quite straightforward to me.
Title: Re: Seeing the curvature of the Earth directly
Post by: Matthew7 on March 17, 2019, 10:28:14 PM
The author tells us that it took over 400 photos to get the one that he wanted (http://archive.fo/57WTh):

"In all the images I took today - there were over 400 in total"

He goes on to tell us that the horizon was curved and the beams were straight in the remainder of the 400 photos that he does not show us:

"the curve of the horizon shows the same, while the straight edges stay straight."

However, of the couple of photos he shows us, the curvature of the beams are inconsistent:

Straight:

Then the author shows us a version with the beams tilted in comparison with the horizon. In this one we can see that there is clearly curvature on the beams:

I bet that if I took over 400 photos of distortion, I could eventually get what I wanted too.

I simply printed off the picture and put a ruler against the bar edges: There's no consistent curvature to them the way there is the horizon line. The bars tilt in some images, they're a bit blurry and have some unevenness true, but tilted, blurry or uneven edges do nothing to falsify the horizon's curve which the author claims is in all 400 images. Think about it: The telling thing is that the line of the bars, be it level, wavy, tilted or even if they had some apparent curve of their own, never follows the curve of the horizon - so whatever is causing the horizon curve isn't a result of the lens, the shape of the imaging surface, or a global distortion of the image in post production. It comes from outside the mechanism of the camera. Nor can it be distortion from the expansion, as the horizon and bars have undergone the exact same expansion and the horizon is clearly curved in a way, and to a degree, that the bars are clearly not. You could even stretch and distort the image so the horizon was flat, but the bars would tell on you because they would then be curved to the same definite degree the horizon actually is but the other way up (a 'smile' instead of a 'frown' if you see what I mean).It is also worth being clear: Both bars would need to be curved, following the horizon curve, along the exact same line for there to be evidence that the horizon curvature was from inside the camera.

You ask the author for all 400 images and go through them, you go ahead Tom, and with enough dedication and you might be able to find a handfull where blur or lighting puts an touch of apparent curve on the bars. But it's the difference between the curve of the horizon and the bars, the bars that in the original image are so incredibly close to the horizon, that shows the horizon curve is not a distortion from within the camera.

WRT QED's ask to see all 400 images, that is fair - but the author expecting people to actually ask for them, if they are that interested, is also fair: They are trying to communicate their finding, and including all 400 in the first instance it would make the piece pointlessly long and might discourage readers.  I worked in research, using optical microscope images. I would analyse hundreds, tabluate and graph my findings of where certain visible phenomena occured under my test conditions, but any paper I published could only include a few images, because the majority of readers are ready to extend at least a bit of trust and aren't so interested in every single image, and because people's time and attention is limited. But I had them (I may still do in fact) and was always happy to share them - even the whole folder - via a site like mailbigfile.com

It's also fair, obviously, to invite repetition of the experiment under comparable conditions. If I get the time, and if my camera with the decent resolution is still working (haven't used it for years) I'll definitely give this a go: As I said, as far as I get this the important thing is not that the bars are perfectly straight and level, but that they are as close to the horizon as possible and clearly don't show the same curve.
From the same article I note it says this...

Quote
It looks flat, and in fact the horizon IS geometrically flat. Since all the points on the ocean horizon are the same distance away from you, and the same distance below you, the horizon forms a flat circle with its center some distance below your feet.

And I do believe I have pointed this out before, for the very same reason that the photographer state.  So how does a flat horizon prove a flat Earth? 

The photographer also points out correctly that the curvature will only become apparent once you gain enough height.  You need to be able to see enough of the surface area of the Earth before the curve becomes directly apparent.  I made reference to that in the last paragraph of my opening post for this thread.   The photos shown in the posts above will never show any hint of curvature.

That is a fair point in principle, but any actual observer is at least slightly elevated, therefore looking slightly 'downhill' to the horizon, and therefore on a spherical surface should be able to pick up some curvature if they can examine it, in comparison to another line, closely enough. The greater the elevation the greater the curvature will be, so to repeat this well its still a good idea to get high as you can. Or do I misunderstand what you mean?

Jeppspace: What evidence is there in the image that the left and right edges are closer to the shore? And, as you point out, the sea is constantly changing - how could any swell or confluence of waves produce a curvature that stays centred on the middle of the shot, for 400 images?
Title: Re: Seeing the curvature of the Earth directly
Post by: Jeppspace on March 17, 2019, 10:46:13 PM
Quote from: Matthew7
Jeppspace: What evidence is there in the image that the left and right edges are closer to the shore? And, as you point out, the sea is constantly changing - how could any swell or confluence of waves produce a curvature that stays centred on the middle of the shot, for 400 images?

I am unaware of any, it was a presumption based on the fact the photographer himself was near the sea.  ;)

I was commenting on the fact that an ocean, or mass of dynamically changing water, tends to be more active towards its center. Hence the entertainment of Sailors' legendary stories at sea.

No, no, just musing on the science! Cheers.  ;D
Title: Re: Seeing the curvature of the Earth directly
Post by: Matthew7 on March 17, 2019, 10:59:33 PM
That's what I don't get man - why would you presume that any part of the sea in the image was any closer than any other part without knowing the coastline? Or, put another way, without knowing the coastline and the exact pointing angle of the camera, how do you know the centre of the sea isn't on the left, or the right, or out of shot entirely? I just didn't see where the assumption came from. I see that you'd assume the centre of the sea is more active than the edges, although I don't think it's a uniform change like that as, depending on the weather, you can have boats becalmed mid pacific and thirty foot waves just off the pacific coast (just a very crude example)- but not why you'd assume the centre of the ocean was in line with the centre of shot.

Actually, am i right in thinking that a slight tilt of the camera might, if the image were stretched in the direction towards the top of shot, produce and offset hump on a spherical surface? But then the bars would have a definite common tilt in one direction or the other, added to or subtracted from any tilt they had individually.
Title: Re: Seeing the curvature of the Earth directly
Post by: Jeppspace on March 17, 2019, 11:08:29 PM
...depending on the weather, you can have boats becalmed mid pacific and thirty foot waves just off the pacific coast (just a very crude example)...

You worked me out without working me out. Yes, it was just a natural reaction to observations of how water is unpredictably non uniform, much like the similar observation you make here.

Sorry to confuse anybody, time for my bed now. Good night.
Title: Re: Seeing the curvature of the Earth directly
Post by: Matthew7 on March 17, 2019, 11:20:13 PM
I'm a pedant for trying to get the details down man. I once had a job in industry working with industrial cutting lasers - so getting details just right, and working out where they kight go wrong, was a matter of keeping my eyesight and all my fingers. I hope I didn't offend.
Title: Re: Seeing the curvature of the Earth directly
Post by: QED on March 19, 2019, 12:52:32 AM
There are statements that can be found which stipulate that unless the viewer is elevated (I.e., in a high altitude airplane) the supposed curvature would not be apparent. Yet this assumes the optical instrument used is the human eye.

It should absolutely be possible with a high resolution camera to observe whether there is curvature or not, provided the photo includes a large enough horizon, and the image is vertically scaled.

Many of you have in your hands the means of determining this answer. You do not need fancy interferometers or weather balloons.

All you need is a decent camera, a coastline, and a sunny day.
Title: Re: Seeing the curvature of the Earth directly
Post by: Matthew7 on March 19, 2019, 01:31:16 AM
Well said QED.
Title: Re: Seeing the curvature of the Earth directly
Post by: model 29 on March 19, 2019, 03:12:46 AM
I would like to see this independently verified/disputed by folks on here who live on coasts. It is an easy measurement to take, and this would permit independent sources to weigh in.

Whether you are a FEer or REer, this type of test is your honey pot. If you want to see the truth for yourself, that is.

I am quite curious what folks will find, and would be snapping photos right now if I wasn’t smack dab in the middle of the country.
I'll try again next time I go to the dunes down in Oregon.  I've been meaning to get up on a small mountain nearby and line up a camera along a water-level at the horizon.  Simply lining up nearby hills against a farther mountain shows the mountain to be too low for a flat Earth.  Noticed this in a video I did debunking some youtube fe'r by the name Antonio Subirats.
Title: Re: Seeing the curvature of the Earth directly
Post by: Max_Almond on March 26, 2019, 11:09:58 PM
I've recently heard that the mysterious 'author' of these straight edges showing the curve of the horizon photos has posted a video on YouTube going through his collection and, I believe, including a link to a google drive folder containing all the raw images.

I can't find the link at the mo' but I'm sure it wouldn't be too difficult to locate it, for those who are wanting to scrutinise.
Title: Re: Seeing the curvature of the Earth directly
Post by: stack on March 27, 2019, 06:06:41 AM
I've recently heard that the mysterious 'author' of these straight edges showing the curve of the horizon photos has posted a video on YouTube going through his collection and, I believe, including a link to a google drive folder containing all the raw images.

I can't find the link at the mo' but I'm sure it wouldn't be too difficult to locate it, for those who are wanting to scrutinise.

Did some cyber-sleuthing. Google drive folders with all of the images are linked from the vid description.

https://www.youtube.com/watch?v=50DZ4K2bn90
Title: Re: Seeing the curvature of the Earth directly
Post by: Max_Almond on March 27, 2019, 07:41:55 AM
Good work! That'd be this link here:

https://drive.google.com/open?id=1lzXYY_HZ2xrlMPbG-4iDJu8f6QNsQEOo