I love astronomy.

Not just because it is cool. And not just because I grew up around astronomers–both my parents were astronomers.

I love it because a decent understanding of how astronomers do their very complicated work exposes the fact that so much of our scientific knowledge is based upon assumptions about how things work, and we really don’t have a clear grasp of how things work.

This is not a knock on science; rather it is a reminder that there is so much yet to learn, so many possibilities yet to explore, and that whatever arrogant claims people make, the scope of human knowledge compared to what there is yet to discover is minuscule.

I love that!

A great example of this is the uncertainty about the age of the universe and its size. During my lifetime the estimates have varied widely and over the span of the 20th Century–a time during which most people assumed that much of science has been “settled”–the estimated age of the universe has varied between 2 billion years and, as of today, as high as 27 billion years since the Big Bang.

And while most people don’t know this, there was active disagreement about whether a “Big Bang” ever happened for quite a while before it became widely accepted.

If you go to the NASA Goddard Space Flight Center website, you will now find confidently stated the claim that the universe is 13.7 Billion years old. Not 13. Not 14. But 13.7, which is a rather precise number when you think about it. We also learn that through the magic of the expansion of space, which is what the Big Bang really was, not so much the explosion of all the matter itself but the explosion in the size of space itself, with the matter expanding with it, most of the universe is not observable to us since it is so far away that light has not had time to reach us.

Mind-blowing.

Except a new calculation of the age of the universe that is trying to account for a very confusing fact–that many galaxies appear to be much older than the calculated age of the universe–leads to the estimate that the universe is actually twice as old as previous calculations suggest.

Oops. Are we off by a factor of 2? And if so, will new calculations a decade or 3 from now revise the age again?

It’s a question that has vexed scientists for ages: How old is our universe?

The question is simple enough, but as the years go by it’s become apparent that settling on the answer isn’t quite so easy. Even today, the matter remains open to discussion as new research could at any moment upend our previous cosmic conception for the age of the billions of galaxies that comprise our universe.

That’s what happened last week when a new study was released challenging the long-held notion that our universe is nearly 13.8 billion years old. If the findings of this latest research prove accurate, the Big Bang may have taken place 26.7 billion years ago, making the actual age of the universe nearly twice as old as we thought.

…

But the study published July 7 in the journal “Monthly Notices of the Royal Astronomical Society” seems to confirm that previous estimates were widely off. What’s referred to in the new study as the “impossible early galaxy problem” has long baffled scientists who struggle to reconcile why some galaxies thought to have come into existence long after the Big Bang appear to in fact be much older that the universe’s estimated age.

Observed through NASAS’s James Webb Telescope, galaxies and stars like the Methuselah appear to have a a level of maturity and mass typically associated with billions of years of cosmic evolution. It’s a notable observation considering the widely-held belief that they came to existence hundreds of millions of years after the Big Bang.

You may have noticed that there was a lot of interest in the initial images that came from the James Webb telescope, not only because they were gorgeous and cool, but also because they showed a lot of fully formed and apparently old galaxies billions of light years away. They shouldn’t have existed, if you believed our models of how galaxies and stars form, because the images come from light that left the galaxies only a few hundred million years after the calculated time of the Big Bang. (Light takes so long to reach us from these galaxies that what we see is billions of years into the past).

How can a galaxy be older than the universe? By definition, it can’t be. Before space and time existed, nothing did.

Hence the plausibility of this new calculation, which is accomplished by changing some of the assumptions about physics. Space, time, light, and other fundamental characteristics of the universe don’t work as we think they do.

Good! Actually great! I love this result, both because it means that there is so much left to learn, and because it reminds us of something that everybody needs reminding of: we should exercise great humility when it comes to making claims about how things really work.

There is no “settled” science or for that matter knowledge. We get very attached to our models of how the world works. You see this in every claim that the “science is settled,” and every time people are utterly confident of what are very uncertain things.

Of course, this doesn’t mean that we need to be paralyzed; we need models for how things work in order to act, and often those models work very well. But that doesn’t mean they are right, or wholly so.

Lots of “predictions” are based upon models that seem to work until the moment that they don’t. Beautiful and seemingly accurate models of planetary movements were developed based on the entirely incorrect assumption that the solar system revolved around the Earth. People spent centuries tweaking these models until Copernicus upended everything with his assertion that the solar system revolved around the sun (although many ancient Greeks believed this to be the case).

Astronomy is such a wonderful science because it is the most likely of the physical sciences to slap us in the face and remind us of how much there is yet to learn. Our confidence in science so often leads to hubris, and with hubris comes an inevitable fall.

We’ve seen lots of hubris of late, and lots of massive fails as well. Pretty much everything sold to us as “settled science” is at the very least unsettled, and much of it is just plain wrong. Sometimes is it wrong because people are deceiving you, and sometimes just because people are excessively confident in uncertain things.

But in either case, it pays to remember that nothing is really “settled.” Sometimes you should be very reluctant to abandon a robust model–especially when it has proven very useful over time–and other times you should be willing to dump it quickly when it seems quite shaky. Orbital mechanics is of the first type and climate models of the second.

In any case, you should always remember that nothing is settled. We are simply more and sometimes less confident that our models work.