The recent constructive exchanges between Martillo and Physics Monkey in this thread encouraged me to look at it more careful (despite the thread title, which for me is a real “don’t open" sign.) Thus I went back and skimmed most of the pages. There I found a few points that might be worth disinterment (to save others and hour or more of old post looking) for continued discussion: (1) Martillo stating: “The notion of absolute position have sense when we think in the place of things in the Universe. It's relative to an absolute frame of the Universe.” and Wesmorris refuting, much in the way I would, but I want to asked Martillo: Does he find the “Dots on an expanding Balloon” a useful analogy for understanding how it can appear to every dot that all the others are moving away from the home dot with speeds that increase with distance (Hubel’s law and recent variations from it)? If M. finds this a convenient way to think of the observed expansion of the universe, can the origin of his “absolute frame” be on any dot? , any point in the universe? If not where is it? Perhaps M’s response will be: “in the center of the balloon.” Anticipating this, I note that the balloon analogy is a 2D model of a 3D universe. So is the center of 3D space in some unknown higher (fourth?) spatial dimension? I.e. If the center of the Absolute Refeence Frames (ARFs) is on each dot (in 2D model) there are too many ARFs (one on each dot) and all in relative motion wrt each other. ARF, ARF, ARF, ARF, …. If, the unique ARF origin is in a higher spatial dimension, then for us limited 3D creatures, it does not exist. Again, ARF, ARF, ARF, ARF, …. (I knew if I looked around I would find a replacement for Giestsekel to ARF ARF, ARF, ARF, ARF, …. at, but I do miss Giest’s pretty pictures ) (2) Aer (I think, but not sure as lost the page now) gave example of proton passing Earth with speed wrt Earth of v =0.9999 (100 “9”s) and noted that to us Earthlings it is more massive that the Earth, and I expect he is correct, or a few more “9”s would make it so. The poster went on to note that it still follows the “straight line” thru space time. As Earth’s gravity has curved local space’s “straight. I am not sure what I think of this. Surely it gives Earth a hell of a good impulse towards the point of closest approach and breaks everyone‘s bodies (kills them) in doing so but that should not be much concern to us physicists. Please Register or Log in to view the hidden image! ” I am wondering if the better way to look at the Earth/Heavy Proton interaction is not to have its trajectory bent by Earth’s gravity (or guided by the locally warped “straight” line Earth’s gravity achieved) but to think of it as relocating Earth so that Earth’s gravity was not much influence on its trajectory. I.e. the heavy proton goes essentially the same trajectory as if Earth were not near the trajectory line, warping space. Any other views? Comments? I think Earth/ heavy proton encounter is an interesting question, but even if it density in Earth’s frame is great enough to become a black hole, I am sure it does not. In its own rest frame, the density needs to exceed the black hole collapse density to form a BH. There its mass is only 1 Gev and we know that protons are stable (at least against becoming black holes.) so no BH, nor will any accelerator make one, except possibly by colliding two particles to put a lot of energy in their rest frame. Comments? (3) Pete said: “... The Wright brothers' work was firmly grounded on a century of established aeronautical science…..” in response to: As usual, Pete is correct, but I would like to add to Pete’s reply, based on a few hours spent in the museum at Kitty Hawk, NC, reading in their workbooks about their wind tunnel experiments. Some of their measurement could not be reconciled with aerodynamic theory. Eventually they realized some published values (of the compressibility I think it was) of the physical properties of air were wrong, and used their experiments to get the correct values and continue to study lift in their crude wind tunnel. They, unlike others, also realized the main problem would be control, and invented “wing warping” to achieve control of flight. They were real scientists, even if they knew how to fix a bike. Least you think I have some hidden reason to glorify the Wright Brothers, let me add they get much too much credit (MHO). Without any impartial observers, they claim to have flown after rolling DOWN Hill with a good wind providing most of the lift (like a kite) on a track on a sand dune and landed at a significantly lower altitude than the point where they took off - Hell, I can do that, even at my age, without any wings or motor, but would use a big compessed spring instead of the motor and might get a few bones broken when I hit the mattresses after my "flight" of many yards. Santos Dumont, in front of hundreds in Paris, took off from a level field, flew around for some time (several minutes at least) and returned to the field to land at the same elevation only a few years after the Wright brother’s down hill “flight” of a few yards. SD deserves the credit for the first true powered flight. In the time I have been here, I have noticed that most of the “crackpots” are ignorant of science’s history and feel no need to know why accepted physics is as it is - a complex web of many interrelated facts and theories, which are generally successful in consolidating many observations and capable of making testable predictions. They all seem to want to start with a clean page and write down the “truth” while sitting in their armchair, ignorant of the work/experiments etc that have gone before except a few famous experiments they may have read about in an newspaper or in the internet. 4 Sorry, after spending an hour, scanning most pages, of this thread, that is all I found of real interest. There is a lot of exchange about the twin paradox, some even correct!- and a lot of “that’s horseshit” slung as if it were a logical argument, but nothing new to report. (If I missed your “wonderful post” I am sorry.) As a reward for having read all the way to the end (if anyone did) let me offer some (?) humor: I note this thread prefers to sling "horseshit" instead of the ususal "bullshit" - I guess that proves things really are relative. Please Register or Log in to view the hidden image!