I read your post several times more than I've watched that experiments' video, just to try and see something you continuously claim it is obvious. I really can't get a grip on your reasoning and logic, which makes it very difficult to explain complexity of observational and logical errors you've made (unconsciously or deliberately, it makes no difference). Is there actually an appreciable lag you are observing? Or could it be just the mismatch in what should have a been a simultaneous start of 2 balls? Are the inclinations of both tubes matched in at least 1/10th of degree? Since velocity loss (or should be very obvious and progressive (or gradual) and it is obviously not, a reasonable mindset would explain it otherwise. It's either : a) no velocity loss/extra friction due to curved path or b) obvious velocity loss of cca 21% progressing as the ball runs through the curve. Can I kindly ask you to accept this two versions of reality? Because it can NOT be any different, there is no 3rd option and there is no twilight-zone kind of relativity hokus-pokus.bongostaple » October 9th, 2016, 3:29 pm wrote: There absolutely is an appreciable lag - in both cases. At the first quarter mark, the circle path ball has travelled a quarter of a revolution of the circular path, and the straight path ball has travelled a quarter of the line from '0' to '4'. These two markers are not in any way equivalent in distance travelled. In the time the straight path ball travelled a quarter of four, or 'one diameter', the circle path ball travelled (pi * d) / 4 which works out at about 79% of the straight path first marker distance.
Conclusion: We are seeing a 21% miss.
Can you answer it directly, is it option a) or option b) ? As soon as you come to the conclusion that correct answer would be a) , we can start seriously discussing how to make the experiment better with improvements to its setup. Until then such discussion is useless, all your arguments that are based on assumption of answer b) from above, are without any value, impossible to mechanically explain and interpret by known equations.