The scientific method, according to some cosmologists

The uncertainty of science: In two somewhat self-righteous press releases today from two different academic organizations, scientists who have been for three decades touting the somewhat uncertain evidence that the expansion of the universe is accelerating, thus requiring the ad hoc creation of something they label “dark energy” to explain it, insisted that their theory is still right despite publication of a paper last year that said their evidence was weak and unconvincing.

The headlines of the first press release is especially insulting to the very concept of the scientific method:

• Royal Astronomical Society: ‘Crisis averted’ as experts confirm universe’s expansion IS accelerating
• University of Southhampton: Universe expansion still accelerating say astronomers

Both press releases have an arrogant attitude to those questioning the theory of dark energy, but the first is truly egregious. It is filled with bombastic claims, such as calling it “a crisis” for anyone to dare question the theory. It also uses a reliance on authority to justify its position (“The researchers … include two Nobel Laureates and represent institutions worldwide”). And finally, it demands that such questioning end, so “we can get back to trying to understand what this dark energy actually is, rather than wondering if it exists at all.”

The 2025 study that questioned the existence of dark energy — claiming the universe’s expansion rate was not accelerating — was actually part of a string of similar results. It did not occur in a vacuum, and actually stemmed from the overall uncertainty of the original supernova data.

Scientists in the 1990s had begun by assuming the brightness of a certain type of supernova is always the same, no matter when or where it happened. They then measured such supernovae in the early universe and found their brightness suggested the universe was expanding faster than predicted.

Since then, multiple studies have noted the weakness of that basic assumption. We don’t know enough about these supernovae, nor do we know enough about the environment in which they occur in the early universe.

The bottom line: The theory of dark energy might fit the facts as we have them now, but those facts remain uncertain and open to doubt. It is perfectly reasonable to question those facts, and to try to stifle that questioning violates the very fundamentals of the scientific method, which demands you question everything, that you search for truth wherever it may lead.

Sadly, this pattern of arrogance by cosmologists is not new. It has grated on my nerves since my first interview with a cosmologist in 1995, when she got insulted and huffy because I dared ask her some tough questions. This arrogance has gotten so bad that in 2022 24 scientists signed a petition protesting the censorship of their work for questioning the Big Bang theory.

Meanwhile, the data remains uncertain and actually contradictory. One set of data says the Hubble constant (the expansion rate) is one number, while another equally trustworthy data set says the constant is another number. And almost a decade of intense research has failed to resolve the conflict.

This new work might have proven the dark energy theory is still viable, but the press releases do little to convince anyone.