Physics Has the Answer to Dealing with a Hard Emotion

We don’t know why some people are diagnosed with autism spectrum disorder. We don’t have a medicine that cures the COVID-19 infection. Some people deal with our collective ignorance by manufacturing answers. They assert that the vaccine for measles, mumps, and rubella (MMR) is the cause of autism and advocate for an anti-parasitic drug called ivermectin to treat COVID-19. Extensive research has shown there is no connection between the MMR vaccine and autism, and ivermectin is ineffective to treat viral infections like COVID-19.

It is hard to accept uncertainty and the unknown when it comes to health and biology. Perhaps we should take a lesson from another branch of science, where uncertainty seems much more acceptable and non-experts do not rush to fill in gaps in our knowledge: Physics.

The Cosmological Constant Isn’t Constant

Recently, new findings by experimental physicists made news. It has to do with something called “dark energy.” Almost a century ago, astronomer Edwin Hubble made the startling discovery that the universe is expanding. Then, in a discovery that won the Nobel Prize in 2011, astronomers startled the scientific world by showing that not only is the universe expanding, but the rate of expansion is accelerating. This increase in acceleration is mysterious—if anything, the gravitational attraction of the trillions of stars in the universe should cause the universe to contract. There must be some force that is working against gravity, and this force is called dark energy. We know very little about dark energy, and trying to understand it is one of the most challenging questions confronting astronomers and physicists today.

Source: Murat Ceri on Pexels

For decades, scientists assumed that dark energy is a constant force, providing a steady push forward to the universe. Now, however, scientists have provided evidence that the universe expanded faster in the distant past than today. Physicists express dark energy mathematically as the “cosmological constant” called lambda. The new data, presented in March at the American Physical Society’s meeting, comes from the Dark Energy Spectroscopic Instrument (DESI) and shows that the cosmological constant is not so constant. Dark energy’s push against gravity fluctuates. One member of the DESI team, Mustapha Ishak-Boushaki of the University of Texas, Dallas, told the New Scientist, “This result about dark energy is something that we did not expect to happen in our lifetime.”

It is impossible to overstate how much these new findings are shaking up the world of astrophysics. The new evidence represents a dramatic shift in thinking about the fate of our universe and will require a host of new mathematics and physics. Yet, astrophysicists seem generally excited that a basic tenet of their field—the constancy of dark energy—has been upset. One can sense them rolling up their sleeves and pondering what it all means, what experiments are now called for to fill in missing details, and how to revamp their theories to accommodate what is now emerging.

We Accept Uncertainty About Physics, but Not Biology

The new findings were reported in popular media outlets like The New York Times and Popular Mechanics, the latter calling the discovery “shocking.” Yet we do not see attacks on physicists for “getting it wrong” or a rush by non-experts to provide alternative models for dark energy or cosmic expansion. People generally seem content to let scientists deal with what is, in fact, a potentially monumental change in how we understand the universe. That’s not the way things seem to go these days when medical scientists face a challenge to long-held beliefs by new evidence or confront an area of uncertainty, like the cause of autism or the treatment for viral illnesses. Scores of people always seem poised to attack scientists and public health experts and offer their own ideas and recommendations. They seemingly do not doubt their assertions—they know that the MMR vaccine causes autism and that ivermectin is an effective treatment for COVID-19.

To be sure, there are important differences between physics and medical science. Problems related to health are naturally more urgent to us than figuring out what will happen to our solar system billions of years from now. And the science of physics, laden as it is with complex mathematics, is probably more difficult for many of us to grasp than the biology of our own bodies. Still, we might take some lessons from how physicists approach uncertainty. First, they broadcast it widely. They are experts at announcing whenever there are disputes in their field and new data challenge current theories. Second, they embrace uncertainty as a challenge, not as a sign of failure. Third, they hold themselves to rigorous standards of experimentation and data analysis, avoiding coming to conclusions until the science permits. Finally, they can change their minds when evidence so demands.

Many things in medical science are uncertain. And we have learned that many things we believed to be true about improving health and preventing disease were incorrect. The only way to find out things like what causes autism, how to treat viral infections like COVID-19, why Black people are more likely to die from pregnancy than White people, and why some people are hesitant to accept vaccines is to fund and pursue more research. How wonderful it would be if we could erase all the uncertainty and have definitive answers to what ails us. But unfortunately, as the physicists know, science just doesn’t work that way. There are things we will just have to continue to work on to get the answers we so desperately desire.