In the last post (part 3), I put forward a hypothesis why the space between galaxies expands. In summary, the galaxies drain energy from the vacuums of space to sustain their (i.e., the galaxies) existence. As energy is removed from the vacuums of space, so is mass (based on Einstein’s mass energy equivalence formula E = mc^2). With less energy/mass in the vacuums, the gravitational force defining the vacuum is diminished, which in turn causes the vacuum to expand.

The above hypothesis would explain the expansion of space between galaxies, but does not explicitly address the question: Why do the galaxies furthest from us appear to be moving away from us the fastest, even to the point of exceeding the speed of light?

To address the above question, let us assume we are located in the Milky Way galaxy, which is true, and we measuring the speed that another galaxy is moving away from us. Let us call our galaxy #1 (Milky Way) and the galaxy we are observing #2. From our point of reference, galaxy #2 is moving away from us, galaxy #1. However, what is really happening? Both galaxies, #1 and #2, are moving away from each other due to the expansion of space between them. Because we are considering our position in galaxy #1 fixed, it appears only galaxy #2 is moving away. For the sake of this example, let assume the velocity we measure for  galaxy #2 as it appears to be moving away from us is V1.

Next, let’s consider another galaxy, galaxy #3, that is more distant from us than galaxy #2. If we were on galaxy #2, we could measure the apparent velocity of galaxy #3 moving away from galaxy #2. Again, for the sake of this example, let us assume we measure it and its value is V2. However, from our position on galaxy #1, galaxy #2 is moving away from us at a velocity of V1 and galaxy #3 is moving away from us at the combine velocity of V1 +V2. Let assume the sum of V1 + V2 = V3. The observation of the velocity of galaxies moving away from us  will appear greater for galaxies further away from us. However, this is actually not true. If we were on galaxy #2,  we would measure galaxy #1 (Milky Way) moving away from us at the rate of V1 and galaxy #3 at the rate of V2. However, since we consider galaxy #1 (Milky Way) our fixed point of reference, we measure galaxy #2 moving away from us at a velocity of V1 and galaxy #3 moving away at a velocity of V3 (V1 + V2).  Using this simple example, we can argue that as the space between galaxies expands, from any fixed measuring point on any galaxy, the speed of galaxies moving away from our fixed measuring point will increase the further a galaxy is from our fixed measuring point.

If we consider the vastness of space and the billions (essentially uncountable) galaxies, from our fixed measuring point within the Milky Way galaxy, all galaxies will appear to be moving away from us (as the space between our galaxies expands) and the more distance a galaxy is from us, the faster it will appear to be moving away from us. The important word is the last sentence is “appear.” In reality all galaxies are moving away from each other at a velocity proportional to the expansion of space between the galaxies. However, from a fixed measuring point, the furthest galaxy from our measuring point would appear to be moving at sum of all galaxies we measure between us and the galaxy we measure  moving “away” from us. If there are billions of galaxies between us and the furthest galaxy, the sum of velocities could appear to exceed the speed of light, which would violate Einstein’s theory of special relativity.

Einstein’s theory of relativity is considered the “gold standard” among theories. It has stood scientific scrutiny for over one hundred years. According to Einstein’s theory of special relativity, no mass (for example a galaxy) can move faster than the speed of light. To get around this, current cosmology theories argue that it is the space between these distance galaxies that is expanding faster than the speed of light. However, they offer no reason why we should accept this hypothesis. In fact, it is illogical to argue that as we look at more distant galaxies, the space of those galaxies is expanding faster in proportion to the distance from our measuring point. My explanation above, removes this illogical premise and provides a relatively simple way to understand the phenomena.

As far as I know, this series of posts (parts 1-4), is the only body of work that explains and ties together the role of dark matter, the nature of dark energy and the accelerating universe. It is completely consistent with all observed phenomena and does not violate any known physical laws.