If you look at a spiral galaxy that is moving, you will see that something doesn't add up. The stars rotate around the center in way which looks like there is more mass in the center than there ought to be. There are only 2 possible explanations:
- Length Contraction: The galaxy is moving relative to the observer and so this shows up as a length contraction. From special relativity, we know that the length measured by the observer is shorter than the actual length... and so the spiral galaxy has stars rotating much farther out than we observe.
- Relativistic Momentum: A star which is orbiting in a spiral galaxy has relativistic momentum, which makes it appear heavier to an observer. The further out it is in the spiral, the faster it's velocity is with respect to the center of the spiral, and the greater its relativistic momentum.
This is a work in progress and very preliminary. I'll do another write-up once we have corrections that can be applied to cosmological models.
