Stephen Hawking, along with 32 other scientists, have penned an angry letter in response to an article that was earlier published in the Scientific American and discussed an alternative theory about the beginning of the universe.
Inflation And Big Bounce Theories
In their letter, the scientists declared their categorical disagreement on a number of the statements that the article made. They also provided an explanation as to why the theory of inflation remains to have the upper hand when it comes to explaining the cosmos origins.
Hawking and many other scientists believe in the theory of inflation, which describes the rapid expansion of the universe following the Big Bang. In February, however, three physicists, namely, Paul J. Steinhardt, Anna Ijjas, and Abraham Loeb proposed another theory claiming that the "Big Bounce" offers a better explanation for the origins of the universe.
In "Pop Goes the Universe," the three physicists challenged the theory that the universe is ever-expanding, citing that the most recent data of cosmic microwave background (CMB), the light emitted after the Big Bang, created concern about the widely accepted inflation theory.
The CMB data that they referred to were mapped by the European Space Agency's Planck space observatory and announced in 2013. It revealed how the cosmos expanded very fast prior to settling down and becoming the universe we now know of. For many experts, the findings back up models associated with inflation theories.
The three physicists, though, disagreed with the interpretation, arguing that since the production of the 2013 CMB, more accurate data have been collected and added more evidence to arguments that the Big Bang and inflation cannot sufficiently explain how the universe began.
The scientists also claimed the beginning of the cosmos could be more likely explained by the Big Bounce theory, which proposed that the universe works on a cycle. The idea is that the universe could be expanding but may start contracting once its energy has ran out. When it becomes too small, the universe will start to expand again.
The physicists said that scientific method cannot evaluate inflationary cosmology and claimed that some scientists who accept the inflation proposed discarding empirical testability, which necessitates evidence.
Statement From 33 Scientists
Hawking and colleagues expressed their disapproval to the idea of the physicists and also noted that they do not have an idea about the scientists that the three physicists claimed to have proposed to promote nonempirical science.
"No one claims that inflation has become certain; scientific theories don't get proved the way mathematical theorems do, but as time passes, the successful ones become better and better established by improved experimental tests and theoretical advances," Hawking and colleagues wrote. "This has happened with inflation."
Ijjas, Steinhardt, and Loeb said they were disappointed by the response of the 33 scientists, citing that respectful disagreement is possible in a healthy scientific community. Despite pointing out the problems, the scientists said that they were not disregarding the work of the people behind the inflation theory.