In 2011, the Nobel Prize in Physics was awarded to three physicists for their discovery that confirmed that not only was the universe expanding, but also that it was doing so at an accelerated rate driven by the repulsive force of the strange and elusive substance, dark energy.
Uncovered based on the analysis of type Ia supernovae, this finding has been regarded as one of the most important astronomical discoveries in scientific history.
However, recent analyses of more than 740 of these thermonuclear explosions of dying stars now challenge this concept of an accelerating expansion. A team of scientists led by Professor Subir Sarkar of Oxford University has published a report in the Nature journal Scientific Reports suggesting that the universe is in fact expanding at a constant rate.
Sarkar and his team claim that the original discovery that led to the belief that the universe is expanding at a constant rate may have been based on a faulty statistical fluctuation.
“We analysed the latest catalogue of 740 type Ia supernovae — over 10 times bigger than the original samples on which the discovery claim was based — and found that the evidence for accelerated expansion is, at most, what physicists call ‘3 sigma.’ This is far short of the five sigma standard required to claim a discovery of fundamental significance,” Sarkar said in a press release.
The infinities of the universe have captured the curiosity and attention of human beings since the third century BC. Specific philosophers and scientists interested in this mystery included Copernicus, Galileo, Kepler and Newton. In the early 18th century, astronomer Edmond Halley made the observation that stars were actually mobile.
However, he argued that this occurred in a static, fixed universe. This conclusion was later negated by Edwin Hubble’s observations that suggested that the universe was in fact expanding.
The implications of Albert Einstein’s theory of general relativity, introduced many years later, challenged this notion, arguing in favor of an accelerated expansion of the universe — an idea that even he himself found to be “abominable” and condemned.
The possibility of the original Nobel Prize-winning discovery being a mere statistical fluctuation has rocked the physics community to its core.
Principles of standard cosmology such as the idea of a homogeneous universe with matter behaving as an ideal gas are called into question by Sarkar’s discovery. Even the concept of dark energy struggles to fit into this new framework of a constant rate of expansion.
Sarkar’s research serves as a cautionary tale to research scientists and scientific journals. From the relationship between vaccines in autism to the concepts of cloning and human stem cell research, retraction notices of scientific studies from some of the most prominent journals have steadily increased over the past decade. This phenomenon may be due to an increase in the publication of flawed articles.
Further, faulty research may be motivated by the pressures that scientists feel to not only publish ground breaking discoveries but also to publish as quickly and frequently as possible.
However, for the sake of the integrity of science, researchers have an obligation to pursue rigorous verifications of their conclusions and guarantee reproducibility of their experiments. Professor Sarkar hopes his research will serve as motivation for scientists to perform more robust analyses.
“Naturally, a lot of work will be necessary to convince the physics community of this, but our work serves to demonstrate that a key pillar of the standard cosmological model is rather shaky,” Sarkar said in a press release. “Hopefully this will motivate better analyses of cosmological data, as well as inspiring theorists to investigate more nuanced cosmological models.”