Inflation is the predominant theory to explain the first moments of the universe after a proposed Big Bang took place. The theory of inflation holds that an instant after a big band -about a trillion of a trillion of a trillion of a second by some accounts (Hand 2009), the universe rapidly expanded 101,000,000,000,000m, eventually settling for a slower rate of expansion.

Inflation was proposed more than 30 years ago by Andrei Linde, along with Alan Guth and Paul Steinhardt. However, a growing number of voices, Dr. Steinhardt himself among them, have pointed out that the theory is more the product of circumstantial support and speculation than the result of strong evidence (Horgan 2014):

• Concerning the origin of the theory itself, Dr. Steinberg states: “The whole point of inflation was to get rid of fine-tuning – to explain features of the original big bang model that must be fine-tuned to match observations. The fact that we had to introduce one fine-tuning to remove another was worrisome. This problem has never been resolved.”
• On the “evidence” supporting inflation: “Here is what’s confusing. On the one hand, mounting observational evidence gathered over the last 30 years supports what we thought were the predictions of inflationary theory based on our understanding prior to 1983.”
• However: “We no longer believe that inflation makes any of those predictions so that none of the magnificent observations made over the last 30 years can be viewed as supporting inflation.”
• Additional problems with the inflation theory include (Hand 2009): In order for inflation to occur, a reversal of gravity is necessary. Gravity briefly had to become a repulsive rather than attractive force, something that have never been observed.
• There is no known cause for inflation. What did the inflation or why are still a mystery
• Not only there is no known cause for inflation to occur, there is no obvious reason as to why the fast expansion stopped and slowed until the rates we observe
• Inflationary theory does not shed light on the origin of the universe. It is a theory of “how it all began just after the beginning” (Hand 2009). Therefore, the Big Bang remains a singularity
•  Dr. Steinhardt points to the fundamental problem when considering the theory of inflation as a whole: “…the inflationary paradigm is fundamentally untestable, and hence scientifically meaningless.” (Steinhardt 2014)

Inflation is the prevailing theory among many physicists to explain the initial instants after a supposed big bang took place. However, 30 years after its inception and continuous research by scientists around the world, no single solid piece of evidence for it has been found.

Submitted by Johnny R. Maury-Evertsz, M.Sc.

References

Conceive ScientificAmerican.com, December 1st.
Hand, E. (2009) Cosmology: The test of inflation. Nature 458, 820-824.
Horgan, J. 92014) Physicist Paul Steinhardt Slams Inflation, Cosmic Theory He Helped.
Conceive ScientificAmerican.com, December 1st.
Steinhardt, P. Big Bang blunder bursts the multiverse bubble. Nature, (June 3, 2014).