Offline edby

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Re: Repeat Bedford level test?
« Reply #80 on: May 17, 2018, 08:25:39 AM »
Yule’s report is below. Why repeat? Nil scientific value, but huge educational value. Engage with Flatearthers, explain the geometry, and get them to agree what would be seen were the 6 mile stretch of water to be flat, and if the three points were exactly the same height above.

Would have great value as a multiple schools project, could be the subject of a BBC documentary etc. Education is the point, and re-creating trust in the scientific method. Plus March 2020 is the 150th anniversary.
 
Quote
REPORT OF THE SEVENTY-FIRST MEETING OF THE BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE HELD AT GLASGOW IN SEPTEMBER 1901.
pp 725-6.
5. The Experimental Demonstration of the Curvature of the Earth's Surface.
By H. Yule Oldham, M.A.
In 1870 Dr. A. R. Wallace performed his well-known Bedford Level experiment. In the summers of 1900 and 1901 a series of similar experiments was made with the special object of obtaining photographic records of the same. The Bedford Level is a portion of the Fens north of Ely, through which in the seventeenth century two great canals were made, shortening the course of the Ouse. Of these, one, the New Bedford river, is tidal ; the other, the old Bedford river, has locks at each end, and presents long, straight stretches of water without current or tide. The six-mile stretch of the old Bedford river between Welney and Denver was selected, as it is perfectly straight, has a bridge at each end, but none in between. The height of the parapet of Welney bridge above the water level was measured, a mark was set up on Denver bridge at the same height above the water-level, and midway—three miles from each end—a mark was set up on a pole at the same height above the water-level. A telescope was then directed from the parapet of Welney bridge to the mark on Denver bridge, and the middle mark was seen to stand up about six feet above the line of sight, agreeing with the effect calculated to be produced by the curvature of the earth's surface.
https://ia801409.us.archive.org/6/items/reportofbritisha01scie/reportofbritisha01scie.pdf

Offline hexagon

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Re: Repeat Bedford level test?
« Reply #81 on: May 17, 2018, 08:40:35 AM »
According to the wikipedia article this was indeed used for educational purposes, but I go along with their remark, that this is no longer needed, because nowadays we have direct proof due to pictures from space.

That's the most confusing thing for me anyway, that the whole discussion is lead by the flat-earth believers as we would still be in England in the middle of the 19th century. Somehow they have not realized, that time has proceed and knowledge and understanding has vastly evolved since then. 

I'm not questioning that you should repeat key experiments from the past. But that's something for students to get a deeper understanding as just by reading books. It's not that physics students do lab courses to solve open questions...
« Last Edit: May 17, 2018, 08:43:44 AM by hexagon »

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Offline Tumeni

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Re: Repeat Bedford level test?
« Reply #82 on: May 17, 2018, 08:58:57 AM »
According to the wikipedia article this was indeed used for educational purposes, but I go along with their remark, that this is no longer needed, because nowadays we have direct proof due to pictures from space.

...and, for those who question the pictures, and call them "CGI", we have the data and observations.
=============================
Not Flat. Happy to prove this, if you ask me.
=============================

Nearly all flat earthers agree the earth is not a globe.

Nearly?

Offline edby

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Re: Repeat Bedford level test?
« Reply #83 on: May 17, 2018, 09:01:48 AM »
According to the wikipedia article this was indeed used for educational purposes, but I go along with their remark, that this is no longer needed, because nowadays we have direct proof due to pictures from space.
But the pictures are supposedly fake. Whereas, if the Flatearthers are invited to the experiment and view the phenomenon with their own eyes, they can't claim it's fake.

I seriously doubt any FEers would accept the invitation. They might say the experiment hasn't been set up right, that the water level has been rigged etc.

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Offline Tumeni

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Re: Repeat Bedford level test?
« Reply #84 on: May 17, 2018, 09:37:29 AM »
But the pictures are supposedly fake.

Doesn't matter if they (pictures taken from satellites of the Earth) are fake or not.

We have live telescope tracking of the satellites, personal observation, laser ranging, data transmission, etc etc to prove the case for satellites. The first three of these can be done easily by anyone unconnected with the satellite industry. The fourth requires purchase or rent of the appropriate gear, and some contractual involvement with the industry, but can still be done by any member of the public.
=============================
Not Flat. Happy to prove this, if you ask me.
=============================

Nearly all flat earthers agree the earth is not a globe.

Nearly?

Offline hexagon

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Re: Repeat Bedford level test?
« Reply #85 on: May 17, 2018, 10:21:11 AM »
According to the wikipedia article this was indeed used for educational purposes, but I go along with their remark, that this is no longer needed, because nowadays we have direct proof due to pictures from space.

...and, for those who question the pictures, and call them "CGI", we have the data and observations.

In the thread about the horizon at eye-level experiment you see how far you go with data and observations. They don't care, they will only discuss about irrelevant details about the execution of your experiment. Any new experiment is as good as an old one. 

Max_Almond

Re: Repeat Bedford level test?
« Reply #86 on: May 17, 2018, 10:56:29 PM »
I don't get it why this should be repeated. It was already repeated. Just check the wikipedia article about it and go for the references within there, e.g. this one: https://ia801409.us.archive.org/6/items/reportofbritisha01scie/reportofbritisha01scie.pdf

Is there any video of that?

A good reason to repeat it is because Bedford Levels is famous; Rowbotham's name is still referred to; and everybody knows about it.

Plus, as we can see, there's still a lot of misunderstanding about the nature of the experiment, and the outcome it shows.

Offline hexagon

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Re: Repeat Bedford level test?
« Reply #87 on: May 18, 2018, 07:11:00 AM »
There's no video about anything that happened in the 19th century, I suppose. Therefor one report is as good as any other.

Re: Repeat Bedford level test?
« Reply #88 on: May 18, 2018, 08:01:15 AM »
According to the wikipedia article this was indeed used for educational purposes, but I go along with their remark, that this is no longer needed, because nowadays we have direct proof due to pictures from space.

...and, for those who question the pictures, and call them "CGI", we have the data and observations.

In the thread about the horizon at eye-level experiment you see how far you go with data and observations. They don't care, they will only discuss about irrelevant details about the execution of your experiment. Any new experiment is as good as an old one.
Why are Tom etc. not carrying out the experiment themselves?

Offline Tontogary

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Re: Repeat Bedford level test?
« Reply #89 on: May 18, 2018, 08:13:58 AM »
According to the wikipedia article this was indeed used for educational purposes, but I go along with their remark, that this is no longer needed, because nowadays we have direct proof due to pictures from space.

...and, for those who question the pictures, and call them "CGI", we have the data and observations.

In the thread about the horizon at eye-level experiment you see how far you go with data and observations. They don't care, they will only discuss about irrelevant details about the execution of your experiment. Any new experiment is as good as an old one.
Why are Tom etc. not carrying out the experiment themselves?


Apparently he is bored with discussing it, probably because he had no answers to the questions posed, and he was making himself look a bit of a tit
« Last Edit: May 18, 2018, 08:59:41 AM by Tontogary »

Also, if you haven't heard of bronies before, that reflects poorly on your understanding of the world that surrounds you. It's practically impossible not to know about them.

Offline edby

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Re: Repeat Bedford level test?
« Reply #90 on: May 18, 2018, 08:32:43 AM »
..  as we can see, there's still a lot of misunderstanding about the nature of the experiment, and the outcome it shows.

True.
Carpenter:
Quote
‘The telescope inverts the picture presented to the eye, so that, in each case, the sky is at th bottom of the picture. But there are the three points in a regular series, so nearly equidistant that the sharpest vision could not detect a fault, one slightly above the other in each case ... To see these views is to see a never-to-be-forgotten sight, and if Mr. WALLACE is not convinced now, he never will be!’

Wallace:
Quote
Mr. Coulcher looked at it, and then Mr. Carpenter, and the moment the latter did he said "Beautiful! Beautiful!" And on Mr. Hampden asking him if it was all right, he replied that it was perfect, and that it showed the three points in "a perfect straight line;" "as level as possible!" And he actually jumped for joy. Then I asked Mr. Coulcher and Mr. Carpenter both to make sketches, which they did.

Both sides agreed exactly what had been seen, and they made sketches which they signed, which still survive. No one was saying anything had been ‘faked’.

But Carpenter thought the observation proved the water was flat, Wallace thought the exact opposite.  More later.

Max_Almond

Re: Repeat Bedford level test?
« Reply #91 on: May 18, 2018, 12:12:57 PM »
Why isn't Tom, etc. carrying out the experiment themselves?

A group of flat earthers tried in 2016. They were pretty happy with what they did. But to observers it looked like a complete gong show.

Video is on youtube.

Max_Almond

Re: Repeat Bedford level test?
« Reply #92 on: May 19, 2018, 06:59:37 PM »
So, ultimately we come down to this:

1. We all agree that water finds its own level, and that water conforms to the shape of the Earth

2. Targets placed parallel to the surface of a body of water will conform to the shape of the surface of the water

3. These same targets, then, will conform to the shape of the earth

4. The Old Bedford River northeast of Welney, between a sluice gate 181m northeast of Welney Bridge and a road bridge just southwest of the Old Bedford Sluice, provides a 5.85-mile perfectly straight stretch of standing water with no obstacles along its length

5. Three targets placed parallel to the surface of the water, at, for example, 0.2, 3, and 5.65 miles will reveal the shape of the surface of the water

6. The targets should be placed high enough to minimise the effects of refraction (for example, at 13 feet above the surface of the river)

7. A telescope or telescopic camera placed at the same height as the targets can be used to view the them

8. Diagrams and scale models predict the following: a) that if the shape of the surface of the water is flat, the three targets will appear to be at the same height as one another; or b) if the shape of the surface of the water is convexly curved, the middle target will appear higher than the other two

9. These two outcomes can only occur with the associated shape: that is, if the shape of the surface of the water is flat, it is impossible for the middle target to appear higher than the other two; and if the shape of the surface of the water is curved, it is impossible for the three targets to appear to be at the same height as one another - regardless of how the elevation or tilt of the camera/observer is altered

10.If the camera is higher than the level of the targets, the following will be observed: a) if the water is flat, the distant target will appear highest, then the middle one, then the near one; or b) if the water is curved, the near target will appear lowest, while the distant target will appear to raise in the frame as the observer raises, until it appears higher than the middle target

11. If the camera is lower than the level of targets, the following will be observed: a) if the water is flat, the near target will appear highest, then the middle one, then the far one; or b) if the water is curved, the distant target will appear lowest, while the near target will appear to raise in the frame as the observer lowers, until it appears higher than the middle target

12. Both the above points are also predicted with diagrams and scale models. Though they are incidental the main point of the experiment

13. Tilting the camera does nothing to alter the apparents heights of the three targets, but merely changes their position, as a group, in the frame

In a nutshell:

1. Three targets and a camera are placed at the same height above a sufficiently long straight body of water
2. Observations are made
3. If the targets all appear to be at the same height, the surface of the river is flat
4. If the middle target appears higher than the near and far target, the surface of the river is curved

Any suggestions for improvements and clarifications?
« Last Edit: May 21, 2018, 06:10:16 PM by Max_Almond »

Offline Tontogary

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Re: Repeat Bedford level test?
« Reply #93 on: May 20, 2018, 12:04:03 AM »
So, ultimately we come down to this:

1. We all agree that water finds its own level, and that water conforms to the shape of the Earth

2. Targets placed parallel to the surface of a body of water will conform to the shape of the surface of the water

3. These same targets, then, will conform to the shape of the earth

4. The Old Bedford River northeast of Welney, between a sluice gate 181m northeast of Welney Bridge and a road bridge just southwest of the Old Bedford Sluice, provides a 5.85-mile perfectly straight stretch of standing water with no obstacles along its length

5. Three targets placed parallel to the surface of the water, at, for example, 0.2, 3, and 5.65 miles will reveal the shape of the surface of the water

6. The targets should be placed high enough to minimise the effects of refraction (for example, at 13 feet above the surface of the river)

7. A telescope or telescopic camera placed at the same height as the targets can be used to view the them

8. Diagrams and scale models predict the following: a) that if the shape of the surface of the water is flat, the three targets will appear to be at the same height as one another; or b) if the shape of the surface of the water is convexly curved, the middle target will appear higher than the other two

9. These two outcomes can only occur with the associated shape: that is, if the shape of the surface of the water is flat, it is impossible for the middle target to appear higher than the other two; and if the shape of the surface of the water is curved, it is impossible for the three targets to appear to be at the same height as one another - regardless of how the elevation or tilt of the camera/observer is altered

10.If the camera is higher than the level of the targets, the following will be observed: a) if the water is flat, the distant target will appear highest, then the middle one, then the near one; or b) if the water is curved, the near target will appear lowest, while the distant target will appear to raise in the frame as the observer raises, until it appears higher than the middle target

11. If the camera is lower than the level of targets, the following will be observed: a) if the water is flat, the near target will appear highest, then the middle one, then the near one; or b) if the water is curved, the distant target will appear lowest, while the near target will appear to raise in the frame as the observer raises, until it appears higher than the middle target

12. Both the above points are also predicted with diagrams and scale models

13. Tilting the camera does nothing to alter the apparents heights of the three targets, but merely changes their position, as a group, in the frame

In a nutshell:

1. Three targets and a camera are placed at the same height above a sufficiently long straight body of water
2. Observations are made
3. If the targets all appear to be at the same height, the surface of the river is flat
4. If the middle target appears higher than the near and far target, the surface of the river is curved

Any suggestions for improvements and clarifications?

Points 10 and 11 are incorrect when referring to a curvature.

For point 10 if the camera is significantly above the height of the targets, it will show initially;
1, the targets to be the nearest below both the mid, and further targets with the further target above all of them,
2, Then as the camera is lowered the further target and middle come into transit, with the closest still below them,
3, Then as further lowered the furthest target and closest come into transit, with the middle target above the other 2,
4, Then as the camera is lowered more the closest and middle will come into transit, with the furthest seen below the other 2,
5, All three targets will be seen with closest above the middle above the furthest when the camera is at the same level as the targets,
6, If the camera is lowered further, below the target height, the targets will grow further apart, and at some point the further target will not be seen.



Point 11 will start with point 6, and then 5 and then 4  then 3 then 2 then 1 as the camera is raised.

However depending on the height of the targets in the first place, there may not be the opportunity to see point 5 if the targets are very low to the water.

Also, if you haven't heard of bronies before, that reflects poorly on your understanding of the world that surrounds you. It's practically impossible not to know about them.

Max_Almond

Re: Repeat Bedford level test?
« Reply #94 on: May 20, 2018, 12:55:20 AM »
It looks right as I've written it; perhaps what I intended with my words is being understood differently, though?

Point 6 suggests a target height of 13 feet. I think this should be enough.

Thanks for your input though. :-)
« Last Edit: May 20, 2018, 02:58:09 AM by Max_Almond »

Offline Tontogary

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Re: Repeat Bedford level test?
« Reply #95 on: May 20, 2018, 01:42:43 AM »
It looks right as I've written it; perhaps what I intended with my words is being understood differently, though?

Point 6 suggests a target height of 13 feet. I think this should be enough.

Thanks for your input to though. :-)

With point 11, it is not necessarily true, as if the observer is lower the mid point target will actually lower until it is in transit with the far target as the observer raises, and eventually appear lower than the far target.

Also, if you haven't heard of bronies before, that reflects poorly on your understanding of the world that surrounds you. It's practically impossible not to know about them.

Max_Almond

Re: Repeat Bedford level test?
« Reply #96 on: May 20, 2018, 01:52:50 AM »
With point 11, it is not necessarily true, as if the observer is lower the mid point target will actually lower until it is in transit with the far target as the observer raises, and eventually appear lower than the far target.

Are you referring to 11a or 11b?

Offline Tontogary

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Re: Repeat Bedford level test?
« Reply #97 on: May 20, 2018, 02:05:41 AM »
With point 11, it is not necessarily true, as if the observer is lower the mid point target will actually lower until it is in transit with the far target as the observer raises, and eventually appear lower than the far target.

Are you referring to 11a or 11b?

11b, if the observer is lower than the hieght of the posts, then the mid target will appear to be above the far target, and then to get closer to the further one the higher the observer goes, until at some point well above the target heights, the mid target transits the lower one, and becomes underneath the far target.

Also, if you haven't heard of bronies before, that reflects poorly on your understanding of the world that surrounds you. It's practically impossible not to know about them.

Max_Almond

Re: Repeat Bedford level test?
« Reply #98 on: May 20, 2018, 02:23:59 AM »
11b is about what would be seen on a curved surface if the camera was lower than the height of the targets.

But you are mentioning what would be seen if the camera was higher than the targets.

That's 10b.

Maybe looking at the video on page 4 will help?

(I did notice a typo in 11a though - fixed now - so thanks for that. :-)
« Last Edit: May 20, 2018, 02:44:53 AM by Max_Almond »

Offline Tontogary

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Re: Repeat Bedford level test?
« Reply #99 on: May 20, 2018, 04:24:58 AM »
11b is about what would be seen on a curved surface if the camera was lower than the height of the targets.

But you are mentioning what would be seen if the camera was higher than the targets.

That's 10b.

Maybe looking at the video on page 4 will help?

(I did notice a typo in 11a though - fixed now - so thanks for that. :-)

“11. If the camera is lower than the level of targets, the following will be observed: a) if the water is flat, the near target will appear highest, then the middle one, then the far one; or b) if the water is curved, the distant target will appear lowest, while the near target will appear to raise in the frame as the observer raises, until it appears higher than the middle target”

I would suggest you watch your video again. Right at the end, it clearly shows, if the camera is BELOW the cups, the nearest is the highest, then the middle, then the furthest.
As the camera is raised up the nearest cup drops to be eventually in transit with the middle cup, and the middle cup is dropping (relative to the far cup) At this point the camera is above the line of cups.

Do a drawing and you will see, as you raise the camera, which is BELOW the level of the cups, then the closest and mid cups close the gap to each other, and close the gap to the far cup. It follows a natural progression.

At no point with the camera below the plane of the cups and then being further raised can either the closest or mid cups appear to raise up higher, as the camera is raised, relatively to each other or to the camera.

Hang 3 objects from the ceiling the further one below the mid one and the closer One higher again in a sort of arc. Look at them when sitting down. Now stand up and look at them again. There will not be any of them that has raised up. It is perspective.

A simple line drawing with the 3 objects on a curve, draw lines through the furthest and middle, furthest and nearest and then middle and nearest. You will see the lines cross a vertical (depends how far behind the nearest cup) this is where you see the cups in transit.

It depends on how much lower than the plane of the targets the camera is situated as to

You need to get this right, or the observation is nonsense.

Also, if you haven't heard of bronies before, that reflects poorly on your understanding of the world that surrounds you. It's practically impossible not to know about them.