Reviewed by Alex SmithFeb 8 2022
For a long time, physicists have been confused about why the cosmos emerged to have been accurately tuned to promote intelligent life.
A multiverse of multiple parallel universes, each with different physical parameters, is predicted to exist by some cosmological inflation models, combined with string theory. The multiverse provides one explanation to the fine-tuning problem of why our cosmos seems to have just the right parameters to harbor intelligent life. Image Credit: Maayan Harel for the Foundational Questions Institute, FQXi. © FQXi.
It is extensively thought that if the values of a few physical parameters, like the masses of elementary particles, were tweaked, even little, it would have hampered the development of the components that are essential for life in the universe—such as stars, planets, and galaxies.
However, recent studies performed give elaborate information in a new report by the Foundational Questions Institute, FQXi. It suggests that intelligent life could have developed under significantly various physical conditions. The claim undermines a significant argument in assistance of the proof of a multiverse of parallel universes.
“The tuning required for some of these physical parameters to give rise to life turns out to be less precise than the tuning needed to capture a station on your radio, according to new calculations. If true, the apparent fine tuning may be an illusion,” states Miriam Frankel, who authored the FQXi report, which was produced with assistance from the John Templeton Foundation.
In the past few years, the subject of fine tuning has attracted few keen minds in physics.
Through probing the physical laws of the universe and accurately pinning down the values of physical constants—like the masses of elementary particles and the strengths of forces—physicists have found out that surprisingly small variations in these values would have rendered the universe lifeless.
This resulted in a puzzle—why are physical conditions seemingly customized towards human existence?
These serendipitous conditions have been described by a few physicists by invoking multiverse theory, which states that there are an infinite number of parallel universes, each having various physical parameters.
Inside the multiverse framework, it is not highly surprising that humans must have developed in one of the parallel realities in which conditions turn out to be habitable for us. Hence, the fine-tuning puzzle vaporizes.
However, other researchers have stayed doubtful whether the universe is fine tuned for life, at all.
In FQXi’s in-depth report, Frankel investigated the complicated history of research on fine tuning, such as potential explanations for it—like those derived from string theory and the multiverse framework. It also evaluates proposals for experimentally testing such explanations in both a direct and an indirect manner.
The report drafts arguments that fine-tuning is an illusion, thereby observing that life may take a highly varying form compared to naively imagined and that if multiple physical parameters are considered to modify concurrently, it could ease any apparent fine-tuning problems.
This indicates that the universe might not be so finely tuned; it may be able to generate life under a much broader range of circumstances compared to what was thought earlier.
The developments outlined in this report emphasize that the fine-tuning problem is more nuanced than has been discussed previously, with wider allowed ranges for the relevant physical parameters.
Fred Adams, Astrophysicist, University of Michigan
Fred Adams is an expert on fine tuning.
For example, it has often been stated that even finely altering the balance of the forces that govern the atomic nucleus, or the values of basic constants of nature, could impact the development of carbon in stars—required for the growth of organic life—or affect the lifetimes of stars.
This helps prevent them from offering sufficient energy for habitable planets to exist. However, the equations of stellar structure might consist of more solutions compared to what has been realized by the majority of the people.
Stars can continue to operate with substantial variations in the fundamental constants. Moreover, if a particular astrophysical process becomes inoperable, then (often) another process can take its place to help provide energy for the universe.
Fred Adams, Astrophysicist, University of Michigan
Adams work is featured in the report.
“Claims of fine tuning have long split opinions,” stated FQXi’s scientific program manager David Sloan, a physicist at the University of Lancaster, UK, who edited the book Fine-Tuning in the Physical Universe, reported by Cambridge University Press in 2020.
When parameters required for life seem to turn up in suspiciously narrow regions we seek explanations of this as either coincidence or cosmic conspiracy. Finding that these regions could be broader, or that other life-permitting regions exist, weakens the need for such explanations. It could be that there is no conspiracy at all.
David Sloan, Physicist, University of Lancaster
Sloan is also FQXi’s scientific program manager, and Sloan’s research is also featured in the report.