Dark energy – An introduction
Dark energy relates to a form of energy that permeates all of space and tends to accelerate the rate of expansion of the universe. Supernovae observation suggests that there exists an energy density that causes the universe to expand at a faster rate the more it expands. The microwave telescope called “Boomerang” studied the cosmic background radiation (CMB) left over from the Big Bang event. The angular power spectrum showed a peak value at precisely the value predicted by the inflationary model, dominated by cold dark matter. Without the presence of this dark matter, scientists believe that galaxies would never have formed because there wouldn’t be enough gravity to keep them from flying apart. The universe is so finely-tuned that a precise amount of dark matter holds individual galaxies together, while dark energy forces these galaxies apart from one another at an accelerated rate. Together, dark matter and dark energy dominate the cosmos, constituting approximately 96% of all mass and energy.
The model predicts a smaller second peak, which appears to be there but cannot be fully resolved with the initial measurements. The presence of the second peak would send sinking to the bottom competing theories relating the history of the universe and how the cosmos came to be.
Dark energy – an example of fine-tuning
Non-theists and proponents of naturalism have long sought to find the simplest explanation for the cosmos, hoping to avoid any direct evidence for intelligent design. Such a framework would predict a model in which there is just enough matter to equal the critical density to account for a flat universe. It has become evidence, however, that there exists less than half of the amount of matter in the universe than would be necessary to account for a flat universe. Dark energy provides an energy density to make up for the missing matter density, but would necessitate an exceptionally high degree of fine-tuning.
How finely-tuned must this energy be in order to obtain a flat universe? The answer is one part in 10120. This is equivalent to one part in 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,
Dark energy – Conclusion
The nature of the universe reveals that a purely materialistic cause for the observed universe is exceptionally improbable – and cannot be understood apart from intelligent agency. When a model is proven to be inadequate, scientists must be willing to go with the model which best fits the facts. In this case, the proposition of intelligent design is far more consistent with the data than the naturalistic model.
Appealing to possible alternative ways that the universe might have evolved do not make fine tuning untenable. In fact, the vast majority of possible universes would contain no matter at all -- just energy! As Kleban Dyson writes:
"The vast majority of the space consists of states which are macroscopically "dead de Sitter;" that is, nearly empty de Sitter containing only some thermal radiation. A tiny subset of the states are anthropically acceptable, meaning that they contain complex structures such as stars and galaxies, and a very small subset of those are macroscopically indistinguishable from our universe. Inflationary initial conditions occupy an even smaller fraction of the space. Trajectories which pass through the inflationary patch will almost always lead immediately to the MIFOU region, "mixing" into it in a "porous," phase-space-area-preserving manner. The vast majority of the points in the MIFOU region did not come from inflation, but rather from unstable trajectories originating in the dead region. Finally, any trajectory in the dead region will remain there almost all of the time, but will occasionally enter the anthropically acceptable region, and very much more rarely the MIFOU region, and almost never the inflationary region. Therefore, livable universes are almost always created by fluctuations into the "miraculous" states discussed above."