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.

R.I.P.: Amateur astronomer Alan Hale, who co-discovered Comet Hale-Bopp, one of the brightest naked-eye comets in the past century, passed away on June 6, 2026 at his home in New Mexico. He was 67.

One fateful night in 1995, he had just finished observing Comet 71P/Clark and decided to glimpse a few globular clusters in Sagittarius while waiting for Comet 6P/d’Arrest to rise above the horizon. As he focused in on M70, he noticed a faint, diffuse object — a comet that would place his name in astronomical history books alongside Thomas Bopp’s.

Checking his star charts, his email, and the Central Bureau for Astronomical Telegrams (CBAT), Hale fully expected to find that someone else had already discovered the comet he’d spied. On finding all three databases devoid of any mention of a comet near M70, he sent an email to the CBAT team notifying them about his discovery.

At the same time, another amateur astronomer, Thomas Bopp, had spied the fuzzy smudge in his friend’s telescope, while observing from south of Pheonix, Arizona. According to Hale, spotty cell service forced Bopp to drive all the way home to send a telegram to the CBAT team — who were surprised to receive an actual telegram. So Hale’s email arrived first, receiving first billing on the comet, but it’s unclear who observed the comet first.

Comet Hale-Bopp turned out to be the most spectacular comet of the 20th century, easily visible to the naked eye, even in urban areas, and visible for many weeks in the evening sky in the northern hemisphere. All told, it was visible to ordinary people for more than 18 months, a record. Even now, more than a quarter of a century later, no comet has been as bright or as spectacular.

Hale subsequently used this discovery to build a career promoting astronomy to the general public.