Water flows down hill. How do we know that water was perfectly leveled out at the point of the line ups?
Wow. So you think that the water in the two connected tubes could be at different heights because "water flows down hill".
I think that's my new favourite Tom Bishop quote.
It does take some time for water to flow. It isn't instantaneously.
In the video you have provided, at the top of the mountain, he is just holding the water device in his hand, which appears to be wobbly, and a camera in his other hand.
The flow of the water is one concern. The other concern is that the camera is not perfectly level and that there is some room to where things appear "perfectly level".
In have dealt with this question and proved through measurements with a sextant (accurate and calibrated) that the arc of the sky is more than 180 degrees, by pretty much the same amount as is expected for the hieght of the observer.
What dont you understand about that Tom?
If the sky, from clear, sharp horizon, to the south, across the sky to a clear sharp horizon on the north is more than 180 degrees, then the bit below you is less, therefore the horizon is NOT rising to meet you.
I cannot really explain much clearer, and a young teenage child would likely understand that.
Surveying is always in error. Always. Every angle and vertical and position needs to be finely positioned. And even when it is to the best of our ability, it is still in error. There is also lens error, which is always present.
http://whistleralley.com/surveying/theoerror/As any surveyor should understand, all measurements are in error. We try to minimize error and calculate reasonable tolerances, but error will always be there. Not occasionally; not frequently; always. In the interest of more accurate measurements, we look for better instruments and better procedures.
Also see Rowbotham's issues with measuring the horizon
with devices that have lenses, as an example of device error.
An off-the-cuff or hand-held surveying demo is not going to cut it. The tolerances are extremely sensitive, and there are many ways it can be wrong. Slight angles and positions and incorrect device calibration will create different results.
Once you have something that is actually irrefutable to FET, let us know, so we can shut down this website.