I recently had somewhat of a debate with a flat earther and he claimed he performed an experiment in which he proved the earth was flat to himself and therefore could use the same experiment to prove it to others. So, here it goes.
This individual, we will call him "Mike" for this post, claimed he took a 100lb test fishing line 1 mile in length across a glass still like. Each end of the fishing line was attached to a piece of rebar which was pounded 1 foot into SAND. According to him he put each end of the fishing line 8 inches above the water. He claims to have had that line so tight that there was zero sag in the middle which he was able to allegedly confirm by getting into a ROWBOAT and measuring the line at 8 inches above the water and somehow not disturb the water or the boat to get an accurate measurement. He claims that because he was able to measure 8 inches on each end and 8 inches in the middle that this proves that the earth is flat. My argument to him is that there is no way that 1 mile of string would not sag, i dont care how tight you get it because of this little thing call gravity. Second, because he used rebar into SAND, there is no way that the rebar would be solid enough to put tension of any kind of this line. Third, he later had to admit that the measurement he actually got in the middle was not 8 inches but less and that he rounded up to 8. I asked him to provide a video of his experiment and post it up on youtube but as you might have guessed, he has posted no such video. No doubt this is not the wackiest thing heard from a FEer, but I think for entertainment purposes it would be fun to hear what other ridiculously crazy things that a FEer has said in an attempt to prove a flat earth.
Easy answer.
Mike is lying and has never done any experiment like that!
So sorry, it would be a nice experiment, but you simply cannot stretch anything tight enough over such a long distance.
As far as I know, apart from
carbon fibre, the fibre with the best strength/weight ratio is
Dyneema - The world's strongest fiber.
You can buy in many forms such as rope for the sheets on sailing boats from places like
Brisbane Ropes & Splicing, Dyneema.
It is very hard to believe,
but even an 0.02" dia Dyneema fishing line stretched with a tension of 100 lbs (near its breaking strength of 110 lbs)
has a sag of 4' 6" over a 1 mile span.And the Globe has a
bulge of only 2" over a mile, that is each end is only 2" below the centre!
The diameter of the line makes no difference, as the weight and strength increase at the same rate.
The Globe is huge!The sag was calculated by,
SpaceAge Control, Displacement Cable Sag Error CalculatorSuch a pity, but the Globe really has very little curvature.