[JSS]

How could they build a beam tube using FE+EA when no one knows the value of the Bishop constant?

We've already been through this - they built their tube to work for the experiment. This would be accomplished without any knowledge of RE vs FE.

This directly contradicts statements and papers from LIGO itself that they did in fact use knowledge of the Earths shape to build the tubes. They have said they used Earth curvature calculations and explained why they did it.

[Pete Svarrior]

This directly contradicts statements and papers from LIGO itself that they did in fact use knowledge of the Earths shape to build the tubes. They have said they used Earth curvature calculations and explained why they did it.

Indeed - a misunderstanding of FET would lead one to assume that they're working under RET. Where, pray tell, is the contradiction?

[JSS]

This directly contradicts statements and papers from LIGO itself that they did in fact use knowledge of the Earths shape to build the tubes. They have said they used Earth curvature calculations and explained why they did it.

Indeed - a misunderstanding of FET would lead one to assume that they're working under RET. Where, pray tell, is the contradiction?

It is here: "We've already been through this - they built their tube to work for the experiment. This would be accomplished without any knowledge of RE vs FE."

The contradiction is when you said they accomplished building the tube without any knowledge of RE vs FE. They say they did take knowledge of RE vs FE into account.

[Jay Seneca]

This directly contradicts statements and papers from LIGO itself that they did in fact use knowledge of the Earths shape to build the tubes. They have said they used Earth curvature calculations and explained why they did it.

Indeed - a misunderstanding of FET would lead one to assume that they're working under RET. Where, pray tell, is the contradiction?

It is here: "We've already been through this - they built their tube to work for the experiment. This would be accomplished without any knowledge of RE vs FE."

The contradiction is when you said they accomplished building the tube without any knowledge of RE vs FE. They say they did take knowledge of RE vs FE into account.

Did LIGO first attempt to do the experiment with it not raised at all and it hit the surface of Earth?
Or did they assume the Earth was round so they built it raised on one end from the beginning?

[Pete Svarrior]

They say they did take knowledge of RE vs FE into account.

No, they didn't. By your own admission, they worked on the assumption on RE, and make no statements regarding RE vs. FE.

I'm very grateful for you endorsing this hypothesis (knowingly or not), but perhaps you should stop wasting our time with word games?

[JSS]

This directly contradicts statements and papers from LIGO itself that they did in fact use knowledge of the Earths shape to build the tubes. They have said they used Earth curvature calculations and explained why they did it.

Indeed - a misunderstanding of FET would lead one to assume that they're working under RET. Where, pray tell, is the contradiction?

It is here: "We've already been through this - they built their tube to work for the experiment. This would be accomplished without any knowledge of RE vs FE."

The contradiction is when you said they accomplished building the tube without any knowledge of RE vs FE. They say they did take knowledge of RE vs FE into account.

Did LIGO first attempt to do the experiment with it not raised at all and it hit the surface of Earth?
Or did they assume the Earth was round so they built it raised on one end from the beginning?

They built it from the beginning assuming the Earth was round, it would have been expensive and embarrassing to have to tear it down and do it over!  They did not "raise one end" either, both ends are at the same height, it's the middle of the tube that is about 1 meter difference. What they did was adjust the height of both (three if counting the two arms) ends to compensate for the hump of the Earth's curve. 

What is more interesting than the pouring of the concrete, which could be done in many ways, is that a 4km perfectly straight slab of concrete will be exactly level only at the middle, and at each end will be tilting outward 0.036 degrees. This actually presents a problem, since the optics are suspended on pendulum systems and therefore don't actually line up, so they had to compensate for the deviation with extra equipment. So that's a second place where they had to take the curve of the Earth into account. If the Earth was flat, the two pendulums would be exactly lined up, but they are not, and differ exactly the amount predicted by the Earth's known curve.

[Tom Bishop]

Who said it was impossible on a flat earth?

It was implied when it was brought up to disprove FE. If you think it's possible on a FE then there is no physical impossibility and we're done here.

Yes, it was brought up to disprove flat earth (as many things are and vice versa to disprove a globe earth - That's kinda what is done around these parts, no?), but it wasn't brought up to say it couldn't work on a flat earth.

Why would someone suggest that something disproves FE if they thought it could work on an FE?

[Regicide]

There seems to be a communication barrier here regarding the workings of precision equipment, so let me clarify. EVERYTHING is first modeled to allow for precision construction. EVERYTHING is precut to allow for maximum precision. And finally: a ramp raised on one end works DIFFERENTLY on a flat earth and a round earth.  While the ends may be the same height, the slope of the one on a round earth relative to the ground is curved, while the slope of the ramp on a flat earth is flat. It is impossible to construct an instrument of that precision on a world that differs by as much as 300 cm at one point. They say that they designed it to account for a round earth, and while it is certainly possible to construct a functioning 4 km long laser tunnel on a flat earth, it is impossible to do so while under the impression that it is being constructed on a flat earth.


They didn't just pour the concrete for the base, they curved it away from the ground along the path. That's necessary on a round earth and would ruin any chance of having a functioning system on flat earth. So, once again. Either Caltech is in on the conspiracy, or there is none.

[Pete Svarrior]

That's necessary on a round earth and would ruin any chance of having a functioning system on flat earth.

This continues to be incorrect, even now that you've said it again. In case you were wondering: saying it once again won't make it more true, either.

[stack]

Who said it was impossible on a flat earth?

It was implied when it was brought up to disprove FE. If you think it's possible on a FE then there is no physical impossibility and we're done here.

Yes, it was brought up to disprove flat earth (as many things are and vice versa to disprove a globe earth - That's kinda what is done around these parts, no?), but it wasn't brought up to say it couldn't work on a flat earth.

Why would someone suggest that something disproves FE if they thought it could work on an FE?

I don't think you're looking at it in the same way I am. It would work just fine on a flat earth. No compensation would be needed. No need to engineer a raised height of the laser at either end to compensate for a curved earth. Yet the LIGO engineers did compensate for a curved earth, designed, and constructed LIGO to compensate for a curved earth and mentioned that they did so. And what your argument is, I guess, is that they were mistaken to do so. They went out of their way to compensate for a curved earth when they didn't need to. Is that your argument - They were wrong to bother in engineering and constructing LIGO to take into consideration a curved earth that doesn't exist? Secondarily, if so, why did they bother? Thirdly, what evidence do you have that they incorrectly bothered to do so?

[Tom Bishop]

Who said it was impossible on a flat earth?

It was implied when it was brought up to disprove FE. If you think it's possible on a FE then there is no physical impossibility and we're done here.

Yes, it was brought up to disprove flat earth (as many things are and vice versa to disprove a globe earth - That's kinda what is done around these parts, no?), but it wasn't brought up to say it couldn't work on a flat earth.

Why would someone suggest that something disproves FE if they thought it could work on an FE?

I don't think you're looking at it in the same way I am. It would work just fine on a flat earth. No compensation would be needed. No need to engineer a raised height of the laser at either end to compensate for a curved earth. Yet the LIGO engineers did compensate for a curved earth, designed, and constructed LIGO to compensate for a curved earth and mentioned that they did so. And what your argument is, I guess, is that they were mistaken to do so. They went out of their way to compensate for a curved earth when they didn't need to. Is that your argument - They were wrong to bother in engineering and constructing LIGO to take into consideration a curved earth that doesn't exist? Secondarily, if so, why did they bother? Thirdly, what evidence do you have that they incorrectly bothered to do so?

So you think that the laser could reach the opposite end on a FE whether they made this adjustment for the 'curve of the earth' or not.

Next you are asking "why did they make that adjustment?" and the answer for that is clear: Because they think that the earth is round.

Finally, you are moving the goal posts to demand proof that they are incorrect about the shape of the earth, which really shows the weakness of the original argument which was supposed to be a disproof of FE.

[RonJ]

The constructors of LIGO built a mechanical flat level plane for the beam tube assuming a spherical earth. The center of the tube was at a fixed reference level and a plumb bob would hang perfectly straight. The mechanical surface would form a tangent to the edge of the earth’s sphere.  That means the other ends 2 km distant would have to be elevated about 31 cm on each end.  The ends wouldn’t be perfectly level relative to a plumb bob.  They would form an angle that wasn’t quite 90 degrees.  If the construction was done according to the CalTech website and the earth was flat, then the tube would effectively be bowed upwards and the laser beam wouldn’t make it to the other end.  Since the beam was working as designed it can be assumed that the earth is spherical and of the advertised size.  The laser beam was operating in a nearly perfect vacuum so no refraction could be expected.  This is effectively a better designed and better controlled Bedford level experiment and shows a round earth.  QED. 

[Iceman]

I believe the argument is that the designers may have thought they were accounting for earth's curve, but really they were accounting for the upward deflection of light rays from horizontal due to EA. You would therefore have to demonstrate why the LIGO design cannot support both possibilities - earth's curvature vs EA - which under typical, isolated readings at a similar scale, are argued to be able to produce equivalent results.

[RonJ]

I believe the argument is that the designers may have thought they were accounting for earth's curve, but really they were accounting for the upward deflection of light rays from horizontal due to EA. You would therefore have to demonstrate why the LIGO design cannot support both possibilities - earth's curvature vs EA - which under typical, isolated readings at a similar scale, are argued to be able to produce equivalent results.

According to the FET Wiki: There is an equation stated with an undefined Bishop constant (which makes it useless) that proclaims to show how the underside of clouds could be explained on a flat earth.  It goes on to say: "its accuracy will improve the closer the light ray is to vertical. Therefore, while it is not valid for short-range experiments, it can give an idea of how much sunlight would bend on its way to the Earth, for instance." The LIGO setup is both short-range AND horizontal so the equation in the Wiki wouldn't apply and any EA arguments would be 'undefined'.  What I did show was the LIGO mechanical structure was stated to be designed as a mechanical level surface mounted on an assumed spherical earth.  If the tube was mechanically straight, as designed, and a light beam went from one end to the other and didn't hit any tube walls and hit the opposite end near the center then it would be a good demonstration of a spherical earth.  Effectively the light beam would be forming a tangent to the earths surface.  If the same mechanical mount was placed on a flat earth then the beam tube would have an upwards curvature and the light beam probably wouldn't quite make it to the other end.  This is a nice 'quasi' Bedford level experiment that shows the earth is round.

[Jay Seneca]

I believe the argument is that the designers may have thought they were accounting for earth's curve, but really they were accounting for the upward deflection of light rays from horizontal due to EA. You would therefore have to demonstrate why the LIGO design cannot support both possibilities - earth's curvature vs EA - which under typical, isolated readings at a similar scale, are argued to be able to produce equivalent results.

According to the FET Wiki: There is an equation stated with an undefined Bishop constant (which makes it useless) that proclaims to show how the underside of clouds could be explained on a flat earth.  It goes on to say: "its accuracy will improve the closer the light ray is to vertical. Therefore, while it is not valid for short-range experiments, it can give an idea of how much sunlight would bend on its way to the Earth, for instance." The LIGO setup is both short-range AND horizontal so the equation in the Wiki wouldn't apply and any EA arguments would be 'undefined'.  What I did show was the LIGO mechanical structure was stated to be designed as a mechanical level surface mounted on an assumed spherical earth.  If the tube was mechanically straight, as designed, and a light beam went from one end to the other and didn't hit any tube walls and hit the opposite end near the center then it would be a good demonstration of a spherical earth.  Effectively the light beam would be forming a tangent to the earths surface.  If the same mechanical mount was placed on a flat earth then the beam tube would have an upwards curvature and the light beam probably wouldn't quite make it to the other end.  This is a nice 'quasi' Bedford level experiment that shows the earth is round.

I do know that they use surveyor/optical levels when building railroads and highways and usually anything that’s a long distance. It’s basically line of sight while level.  Railroads and highways never have to factor in the curvature of the Earth while being engineered or built.     The level we have at work is good for up to 3000’ and there’s better ones than that. 
I guess my question is what kind of level did they use to build it? 
Its not very accurate trying to level something that long of a distance with a hand held level.

[stack]

I believe the argument is that the designers may have thought they were accounting for earth's curve, but really they were accounting for the upward deflection of light rays from horizontal due to EA. You would therefore have to demonstrate why the LIGO design cannot support both possibilities - earth's curvature vs EA - which under typical, isolated readings at a similar scale, are argued to be able to produce equivalent results.

According to the FET Wiki: There is an equation stated with an undefined Bishop constant (which makes it useless) that proclaims to show how the underside of clouds could be explained on a flat earth.  It goes on to say: "its accuracy will improve the closer the light ray is to vertical. Therefore, while it is not valid for short-range experiments, it can give an idea of how much sunlight would bend on its way to the Earth, for instance." The LIGO setup is both short-range AND horizontal so the equation in the Wiki wouldn't apply and any EA arguments would be 'undefined'.  What I did show was the LIGO mechanical structure was stated to be designed as a mechanical level surface mounted on an assumed spherical earth.  If the tube was mechanically straight, as designed, and a light beam went from one end to the other and didn't hit any tube walls and hit the opposite end near the center then it would be a good demonstration of a spherical earth.  Effectively the light beam would be forming a tangent to the earths surface.  If the same mechanical mount was placed on a flat earth then the beam tube would have an upwards curvature and the light beam probably wouldn't quite make it to the other end.  This is a nice 'quasi' Bedford level experiment that shows the earth is round.

I do know that they use surveyor/optical levels when building railroads and highways and usually anything that’s a long distance. It’s basically line of sight while level.  Railroads and highways never have to factor in the curvature of the Earth while being engineered or built.     The level we have at work is good for up to 3000’ and there’s better ones than that. 
I guess my question is what kind of level did they use to build it? 
Its not very accurate trying to level something that long of a distance with a hand held level.

There are some papers on what exactly they used from an engineering perspective. I'd have to dig them up - It was a while ago the last time I found them. I remember something about using GPS. Oh wait, here's one:

Precision alignment of the LIGO 4 km arms using dual-frequency differential GPS
The alignment of the Laser Interferomter Gravitational-wave Observatory (LIGO) using the Global Positioning System (GPS) is described. The LIGO project is designed to detect gravitational waves from astrophysical sources by laser interferometery. There are two sites separated by 3002 km that will be operated in coincidence. At each, site laser beams propagate in two orthogonal 4 km long evacuated beam lines 1.2 meters in diameter. The subject of this article is the alignment of the 16 km of beam tubes using dual-frequency differential GPS. A maximum deviation from straightness in inertial space of 5 mm rms and an orthogonality between arm pairs of better than 5 microradians is reported.

The earth model WGS-84, is described by an oblate ellipsoid with its semi-minor axis, b= 6356752.314 m, along z ˆ E, semi-major axis with value a = 6378137 m, and eccentricity given by (1 - e 2) = 0.993306. R[f] is the local radius of curvature of the ellipsoid at latitude f:

https://dcc.ligo.org/public/0072/P000006/000/P000006-A.pdf

[Pete Svarrior]

The LIGO setup is both short-range AND horizontal so the equation in the Wiki wouldn't apply and any EA arguments would be 'undefined'.

Please do not make arguments about things you don't understand.

What I did show was the LIGO mechanical structure was stated to be designed as a mechanical level surface mounted on an assumed spherical earth.

Unfortunately, the assumption of a spherical earth contradicts your guarantee of it being a "mechanical level surface". Therein lies the crux of your failure - in order for your RE proof to be admissible, RE has to be assumed at the onset.

If the same mechanical mount was placed on a flat earth then the beam tube would have an upwards curvature and the light beam probably wouldn't quite make it to the other end.

This continues not to be the case.

[RonJ]

The LIGO setup is both short-range AND horizontal so the equation in the Wiki wouldn't apply and any EA arguments would be 'undefined'.

Please do not make arguments about things you don't understand.

  OK, fair enough.  If you think that I don't understand, please feel free to provide your versions of the 'facts' for our consideration.  There can be no discussions if all you put out is that I'm wrong without putting out your 'facts' for consideration. I did the best I could with the limited information in the Wiki.

What I did show was the LIGO mechanical structure was stated to be designed as a mechanical level surface mounted on an assumed spherical earth.

Unfortunately, the assumption of a spherical earth contradicts your guarantee of it being a "mechanical level surface". Therein lies the crux of your failure - in order for your RE proof to be admissible, RE has to be assumed at the onset.

Your statement was incorrect.
It is possible to hold a straight edge up to a spherical surface and draw a tangent line.  That was the goal of the LIGO constructors, draw a mechanically straight surface TANGENT to the spherical earth.

If the same mechanical mount was placed on a flat earth then the beam tube would have an upwards curvature and the light beam probably wouldn't quite make it to the other end.

This continues not to be the case.

Agreed.  The earth is a sphere so the construction plans that accounted for that worked out as expected.  You have a beam tube that forms a straight tangent line to a sphere and works as expected.

[Pete Svarrior]

Ron, this is the upper fora. Please drop the wacky font sizes.

It is possible to hold a straight edge up to a spherical surface and draw a tangent line.  That was the goal of the LIGO constructors, draw a mechanically straight surface TANGENT to the spherical earth.

In other words - you do not disagree with me at all, you just like to restate my position and act as if saying it again changes things.

The only part you're slipping up on now is whether the intention was actually realised. Given that the two models would be indistinguishable in this case, you will struggle to substantiate your claim.

[RonJ]

The LIGO website states that they took into consideration a spherical earth during the construction of the beam tubes.  That would require a level foundation.  I would define such a foundation as one with a surface being an equal distance from the center of the spherical earth in all locations on the foundation path.  Once the foundation was constructed,  beam tube mounts could then be installed.  These mounts would have to be a series of ever longer mounts.  The longest would be at the ends of the beam tube and the shortest ones would be at the center.  This would mean that the points along the beam tube would have different distances to the center of the earth.  Just visualize a circle with a tangent line drawn on it, if you can.  If the earth were flat then the different mount lengths would have to bend the beam tube upwards because the mounts of different lengths with the longest at the ends.  I have no indications that the actual beam tube was constructed as claimed on their website.  Perhaps a trip to the site could confirm that.  I'm assuming that the designers were confident enough that the earth was spherical before starting the design.  I have personally confirmed that the earth is a sphere and I'm confident that many others have done so as well.  Probably the designers of LIGO were plenty confident of their 'assumptions' before finalizing the plans.  The data that is coming from the site seems to imply that the beam tube is working as designed. 

You could make the argument that the upward bending of the beam tube on a flat earth would work fine as well because EA bends the light beam upwards, but by how much?  Your Wiki equation give no indication because of the lack of the quantity of the Bishop constant.  I believe that the value of the Bishop constant should be zero.  Then the observed results would fit the equation. The results of the Bedford Canal experiment would be in conflict here as well.  The flat earth theory needs more work and the Wiki needs to be updated with more information.