So when you stand at one end and look towards the other, your brain (yes, even FE'ers brains) makes it look like it's curving upwards...it's an optical illusion.
It doesn't appear that way to me at all.
It seems there might be something telling from a psychological standpoint there. Of course correlation doesn't equal causation, but it's certainly interesting isn't it?
It's completely unremarkable. You've got 5 people who knew the facility in advance (or cheated and searched for the image) and were told that they should be seeing a curve. Then you have 5 people who simply looked at the picture and saw it for what it was - an optically straight corridor with air conditioning. Plus a statistical anomaly of 1 person who didn't know why it looked strange to them, and 1 person who did know why it didn't look strange - but with a sample size of 12 that's only to be expected.
At best, this might demonstrate the power of persuasion and people's naivety. Establish a pre-conceived notion in their minds and they'll find it very difficult to stray away from it.
I saw something odd with the image the first time I saw it before having any idea what it was, although I didn't know why it looked odd. Also, the whole point here is there is *no* curve. The floor of the hallway is perfectly flat. Flat, not level. I agree, small sample size. I just find it interesting, based on those who have also commented, there doesn't appear to be a person from the FE community who found it looked odd. It's certainly not enough to be statistically significant (I didn't expect there to be enough replies for that) but it's interesting to see the difference in snap decisions about the image even from that small group.
Honestly, a photo doesn't reproduce the full weirdness of it. It requires our sense of depth perception to ram our brains into thinking "This is a REALLY long, straight, corridor!" - and then "How come it's not behaving like other long, straight things?" - and finally "Huh! It must be curving upwards!"...which, for all normal definitions of the word "up", it really is!
The "rolling a ball along it" thing is interesting though. The "lowest point" is in the middle - where it's closest to the center of the earth...so the ball rolls along the corridor, then back and forth a bit - and eventually stops in the middle.
That would be a REALLY neat disproof of FET...but sadly, I don't see anyplace where they posted a video of that happening.
I agree that the poll didn't really prove much. Very small sample size and very, very high probability of cheating!