I was talking to Galileo the other day and he told me that motion is relative. A ship is moving relative to the shore and vice versa, and so is everything else in the universe. Nowadays you wouldn't dream of fixing all positions and motion to one universal reference point. Physics should work from anywhere. Nobody can say that any one object is fixed in place. So now I want to measure how fast I can ride my bicycle. By that I mean, what is it faster than, and what is it slower than. Surely I should be able to measure that against anything I want? Surely nobody can say that the speed of anything is fixed? Apparently not, speed is not like position, there is a fixed speed C. Why do you fix the speed of one phenomena, when you wouldn't fix the position of any one thing? By fixing a speed you are fixing the definition of space. A metre is a fraction of the distance light travels in a second. So I can't describe how long something is against anything I want, like I would with motion, instead I have to use the fixed C. Surely the length of something should be like the position of something; anything can move, why can't anything grow? In my own private universe I have a spring and a balloon. All motion is relative, but here so is all length. If I fix length to the spring, then I can investigate the inflation of the balloon when I puff air into it. Now look what happens when I compress the spring. Nothing happens to the length of the spring, but the balloon looks like it is expanding, or 'space itself' is expanding. This is absurd. In this universe, why can't I use Bee instead of C? A standard measure would be a fraction of the distance the bee travels in a second. Then I can use that to calculate how fast I cycle (I'm slower uphill than I am downhill). I should also be able to use the constant speed of my cycling to measure the length of anything. Surely speed, length, and time are as relative as position. Only they're not in relativity, you use C. What excuse does relativity have for violating the 'measurements are relative' principle? Funny things happen when you fix a speed. If I measure a tree branch by riding past it, and knowing that the speed of my cycling is constant, I will find that it seems shorter when lying on a downhill slope. My speed is fixed, so space itself is warped around hills. How long is a tree trunk? You're going to be waiting forever for my to ride vertically. So...speed of cycling times infinity...the tree is infinitely high. Doesn't fixing C to a single phenomenon lead to singularities? If so, what excuse do you have for holding on to this luminocentric view of the universe? From my perspective, the theory of relativity is just the limited case where spacetime is always measured against the speed of one fixed phenomena among many. Sure, some things are 'more constant' than others, and Einstein's C is more constant that my Bee. But that is not a good reason to keep C, because the Earth is more fixed in place than my bee as well, but that doesn't stop me, in principle, from using the bee as a reference frame. There are situations where the current version of relativity doesn't work, in singularities. I get the same problems using Bee. If space is defined with reference to the speed of Bee, and, relative to other things, the bee stops, then space has no meaning there. Surely this can happen with whatever you choose to fix the speed of. I can see one way of avoiding singularities, and that is by not fixing the speed of anything. When I asked another 'expert' about this, I was told 'we looked, and saw that light travelled at C'. But that is not a good excuse. He could have said that he observed that the Earth was fixed, and would have been just as right. Here is one possible way, for instance, to interpret a couple of observations differently to the usual relativistic way... Start with some axioms. I'm going to use Euclid's geometric axioms to describe the universe, so one thing I know by postulate is that space is flat. Einstein used C to figure out that gravity warps space-time, and Euclidean space can't warp, so I'll use a bit of symmetry to figure that gravity determines the speed of light (skipping over subtleties of working). Speed is distance over time, when speed was fixed space-time warped, now they're fixed so speed (in this case of light) must move. So on top of Euclid's geometry, we have light determined by gravity, two axioms. Now when Michaelson and Morley try to measure changes in the speed of light they're not going to see any by comparing both light sources in the same gravity field, as the gravity there will determine the speed of them both. So light speed isn't the same for any observer. A second relativistic effect is gravitational lensing. If Michaelson and Morley look up they might observe light slowing down and speeding up as it flows past massive bodies, going into higher and lower gravitational fields. But as they imagine light to be waves, they're not going to be surprised when it refracts. So using Euclidean space, Newtonian gravity and Snell's law for refraction, I could 'explain' a couple of observations used to support relativity, without singularities. So why would you make spacetime bend to accommodate a fixed C?