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We can see the relative motion of galaxies up to the edge of the observable universe from their red shift. So we know they were all 'in one place' 13 bn years a
by simonh 3y ago
We can see the relative motion of galaxies up to the edge of the observable universe from their red shift. So we know they were all 'in one place' 13 bn years ago. It also means we know what the distribution of initial vectors must have been in this scenario for these galaxies.
So either the conventional view is correct and it's space that has expanded moving the galaxies further apart. This is consistent with a potentially infinite universe. Alternatively all the galaxies we can see were clustered together in a tight lump 13bn years ago and flew apart.
If the latter is the case the origin point would still be visible to us. As long as our initial random velocity was below the speed of light, we would always still be able to see light coming to us from the area of the origin point. With a random initial velocity distribution the fastest half of galaxies would be spread over a volume 4x bigger than that of the slowest half of galaxies. That means galaxy density in th direction of the origin point would be something like 4x higher that it is in directions away from the origin point. But as far as we can tell galaxy and galaxy cluster distribution is even.
Then there's the cosmic microwave background. If this is the after glow of the big bang, we wouldn't see it. All the radiation would have spread out in a shell at the speed of light. So we'd need tome other explanation for the CMB and why it happens to have all the exact characteristics we predicted for a big bang after glow.
- scotty79 3y agoWhere does that 4x come from? This should be noticeable on the simple computer simulation that I made. It wasn't. When I "focused" the camera on a galaxy that had average speed it looked exactly as if it was the epicenter of the whole system if I limted my range of view to end right before the edge. With 4x assymetry in density I should be able to easily tell where the true epicenter was. I couldn't. I'm sure I could use some probability distribution that would show that effect, also gravity could make it more pronounced but uniform distribution without gravity was perfectly symmetrical. My other argument is that if big bang didn't start in a single point then the real centerpoint of it might have never been inside the bubble of our observable universe due to speed of light and space-time expansions as the galaxies moved away. CMB is just the image of hot matter that was close to our location 13bn years ago. Same as faint, highly redshifted images of galaxies from nearly that time. Redshift is mostly from the speed of that matter relative to us back then and spacetime expanding as it was "dragged" by the matter since then. CMB is unique in a sense that it is the image of the last time when all matter around us was so hot and dense that it was opaque. But it doesn't need any special mechanism and it's radiation is no different from our point of view than light from old galaxies.