Earlier this year, three scientists published an article to challenge the widely accepted idea that the universe is ever-expanding. In the paper, they argued that the most recent measurements of the cosmic microwave background (CMB), light emitted after the Big Bang some 13.7 billion years ago, create concerns about “the inflationary theory of the cosmos—the idea that space expanded exponentially in the first moments of time.”
In the paper, they wrote, “Inflation typically produces a different pattern of temperature variation in the CMB (although it can be made to predict almost any outcome). It would also generate primordial gravitational waves, which have not been found. The data suggest cosmologists should reassess this favored paradigm and consider new ideas about how the universe began.”
The group of scientists mentioned the data which were announced back during the 2013 ESA press conference. The revealed most detailed reading till date which seemed to confirm the stationary theory of the universe that the universe expanded extremely fast following big bang before eventually slowing down.
Several scientists in the field didn’t accept the paper warmly as 33 leading scientists including Stephen Hawking signed a joint letter penned by leading researchers in the field.
The scientists published the letter on Scientific American as they said, “We disagree with a number of statements in their article, but in this letter, we will focus on our categorical disagreement with these statements about the testability of inflation.”
“There is no disputing the fact that inflation has become the dominant paradigm in cosmology. By claiming that inflationary cosmology lies outside the scientific method, IS&L are dismissing the research of not only all the authors of this letter but also that of a substantial contingent of the scientific community. Moreover, as the work of several major, international collaborations has made clear, inflation is not only testable, but it has been subjected to a significant number of tests and so far has passed every one.”
After addressing numerous tests and data to support the three decade old theory, the group of scientists said, “While the successes of inflationary models are unmistakable, IS&L nonetheless make the claim that inflation is untestable. (We are bewildered by IS&L’s assertion that the dramatic observational successes of inflation should be discounted while they accuse the advocates of inflation of abandoning empirical science!)”
Afterwards, the three scientists who challenged the inflation theory responded, “We have great respect for the scientists who signed the rebuttal to our article, but we are disappointed by their response, which misses our key point: the differences between the inflationary theory once thought to be possible and the theory as understood today. … We firmly believe that in a healthy scientific community, respectful disagreement is possible and hence reject the suggestion that by pointing out problems, we are discarding the work of all of those who developed the theory of inflation and enabled precise measurements of the universe.”
“Our point is that we should be talking about the contemporary version of inflation, warts and all, not some defunct relic. Logically, if the outcome of inflation is highly sensitive to initial conditions that are not yet understood, as the respondents concede, the outcome cannot be determined.”
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