<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>If I may interject, Saiph said"..either all galaxies are moving away from eachother...or we are the center from our observations. Throw in the fact that EVERY geocentric model has been wrong throughout history and...I go for option #1."So, option 1 is that all galaxies (or clusters of galaxies) are moving away from each other. Thus, we are not at the centre of the universe. Whatever galaxy you were in, it would look like all the distant galaxies are moving away from you. To any observer in any galaxy it would seem like they were at the centre of the expansion as all distant galaxies seem to recede directly away from them. On to your raisin loaf. From the point of view of a raisin, all other raisins move directly away. Each raisin thinks it is at the centre of expansion. Each raisin can consider itself to be not moving, and that all the other raisins around it are moving away... Let's make a model.Now to model an expanding volume with space in it, we need to assign coordinates within that space. For the moment, forget about any edges to the volume, we don't need edges, we just need coordinates in order to measure the expansion of a volume of space. Galaxies come later, so for now just imagine a 3 dimensional grid. At each grid intersection we will assign a coordinate, a point, a dot. Let's say each intersection point is 1 meter apart.Put yourself on a point somewhere in this volume. Whatever axis you look along you see neighbouring points 1, 2, 3, 4, 5 etc meters away, receding off into the distance. Then we introduce some expansion. Let's say the volume grows to 10 times its original size in 1 second! That seems fast perhaps, but this is just a model with easy numbers. The key thing to remember is that the grid expands with the volume.So, here we are, still sitting on our point (but it could have been any point) 1 second later. Now lets look along an axis. We see those neighbouring points are now 10, 20, 30, 40, 50 etc meters away. The volume increased to 10 times the size, and so did the distance between each intersection point on that grid.Our nearest neighbouring point has receded from 1 to 10 meters in 1 second, so it has receded at 9 meters per second. The next point away has receded from 2 to 20 meters in 1 second, so that point receded at 18 meters per second. The fifth point has moved from 5 to 50 meters away in 1 second, so that one has receded at 45 meters per second. The further away you look, the faster a point will seem to have receded! And the view would be the same, whatever viewpoint you choose in the grid.Remember I said the grid of points receded off into the distance.. well a point that was initially 33,000,000 meters away will have moved away to 330,000,000 meters in 1 one second, meaning that it has receded at 300,000,000 meters per second - the speed of light. Any point initially more distant than 33,000,000 meters away from another point will have receded from that point faster than the speed of light. That is the distance were an object recedes at light speed in this "little" model of expansion. If you look at a point that has receded at the speed of light, then from that point, the point you are on has receded at the speed of light. Now I know this is a very simple model, dealing with a simple 10 times expansion in 1 second. This might seem very different from a universe where the rate of expansion was slowing from immense speed and then starting to accelerate, but if you start your grid very small and apply different rates of expansion to that grid, incrementally, over different rates of time, to simulate slowing it down and then speeding it up, when you look at the end result it is essentially the same. (Whenever there is a change in the rate of expansion, it is the rate of expansion for the whole grid that changes).You might be asking how useful this model actually is. Well you might substitute light years for meters and use time-scales over billions of years if you like but the principle remains. If you sprinkle clusters of galaxies through the grid at random and then expand that grid and have clusters move apart with it, you get effects pretty much like how we think the universe expands (you might want to start the grid really small, and only add the galaxies after it has expanded for a bit!).This is a very simplified view, but I hope it is a helpful one! If the whole thing expands and you cannot see an edge, it always looks like you are at the centre, wherever you actually are. <br />Posted by SpeedFreek</DIV></p><p>SpeedFreek and Saipgh:</p><p>It appears to me that either of you are mixing apples and oranges.</p><p>When you create your grid, you place the observing raisin in the approximately center of the box grid.</p><p>But you then expand the box grid with accelerations which must be correct only for an observer outside the box, for whom your thought experiment would be correct.</p><p>I prefer to look at the loaf. If we are a raisin close to the perimeter of the loaf, eg at on end of the loaf, we must see more raisins in one direction than in the other but deep sky investigations show about the same radius to the edge of the universe in all directions.</p><p>To indicate otherwise, we could not use A1 supernovas as a standard candle. Neet huh?</p><p>Your statement "you cannot see an edge' is tell tale, since we can see an edge.<br /></p>