Bursting Inflation’s Bubble
5 Problems People Ignore About Cosmic Inflation
Cosmic inflation is a widely accepted theory, yet it has deep problems that are often overlooked. Inflation proposes that within a fraction of a second after the Big Bang, a special kind of field caused a rapid expansion of the universe. The theory was first developed in the late 1970s, and it has been used to explain several features of the universe, from the evenness of the cosmic microwave background to large-scale variations in the density of the universe. Any theory of the first moments of the universe is bound to rely on circumstantial evidence, but the following five problems may indicate that inflation is not a true theory of the cosmos:
1. The Missing Inflaton Field — Inflation proposes that the universe is permeated by the inflaton field, a positive-energy field in a false vacuum state, that drove the early universe to expand very rapidly. This field has never been detected. Cosmic inflation simply cannot occur without this field. It’s been over 40 years since inflation was first proposed, and it’s notable that there is still no direct evidence for this central component of the theory.
2. Fine-tuning Problem — One problem that inflation was supposed to resolve is that the universe would have to have started with very specific initial conditions to end up with the features that we see today. Subsequent research has shown that in order to do this inflation itself would have to have very specific conditions. In this sense inflation didn’t solve the fine-tuning problem, it just moved it.
3. Eternal Inflation — In most versions of inflation the somewhere in the universe the inflation process is always going on. Not only does this mean that the observable universe would be an infinitesimal part of the complete universe, there would also be so many parts of this “multiverse” that almost any combination of features would happen somewhere. This multiplicity of features means there are few specific predictions of such a theory, which make it virtually impossible to test.
4. Reheating — The Big Bang started with a very hot universe. In models of inflation, once the inflationary period starts the universe cools by a factor of ~100,000, before then returning to its prior temperature. By itself this wouldn’t be impossible, but I don’t know of any direct evidence from this time period. Given the other problems with inflation, could this cooling, then reheating be an unnecessary complication?
5. Inflation and Dark Energy — People that believe in inflation believe that inflation drove the expansion of the early universe, and that dark energy drives the expansion of the current universe. To me this also seems unnecessarily complex. Wouldn’t it be more elegant to have one theory that explains the metric expansion of space throughout the history of the universe?
Given these problems, why would inflation still have such wide acceptance? It does explain some features of our universe, but I believe that the main reason it is accepted is that scientists haven’t found a better theory.
I proposed a theory of spacetime that explains many of the problems touched on by inflation, without the problems listed above. My theory, the entropy scale factor, proposes that the scale of space and time changes with how much information is enclosed within a region of space — sort of like the holographic principle, which sets a limit on how much information space can hold, but for information density levels lower than this limit. In my theory the expansion of the universe, throughout its history, is due to increasing entropy. Expansion happened so much faster in the early universe due to the large increase in entropy during that epoch. Unlike inflation my theory does not require dark energy. The entropy dependent scale factor also requires neither reheating nor an inflaton field unknown to science, and it does not result in an untestable multiverse.
Although a qualitative framework is in place, the entropy dependent scale factor will require numerous quantitative studies before we can tell if it is a useful theory of nature. If you’d like to work with me on such a project, or have any questions or encouragement, please contact me at chriswatsonmd@gmail.com. Thanks for your time!
