We live in a polarized age. It’s hard to find a subject on which people’s views haven’t been politicized and hardened. From Bad Bunny’s halftime performance to new Star Trek shows it seems like everything must pass through the “what side am I on” filter.
It’s exhausting.
Luckily, at least for some questions, human beings have figured out a way to honestly and genuinely change their mind. Without shame and without rancor, science gives you a path to update your beliefs about the world.
Today I want to give you a personal example.
I am emotionally invested in life. What I mean by this is I believe that life is different and quite special from other stuff in the Universe (the science word for stuff is “systems”). One way this belief manifests for me is in the Gaia Hypothesis. Developed by James Lovelock and Lynn Margolis, the Gaia Hypothesis says the Earth’s biosphere (its sum total of living organisms) hijacked the planet’s history. Once life really got going, the biosphere altered how the planet functioned in just the right way to keep Earth in a happy place for life. So, for example, even though the Sun has been slowly heating up over the last 3.5 billion years, the planet’s temperature has stayed relatively constant. Not too hot. Not to cold. Just right for life. According to the Gaia Hypothesis life is always changing the physical and chemical properties of the Earth (think climate) in a way that regulates planetary temperature.
The Biosphere is the part of the “Earth Systems” composed of all the living stuff on the planet.
Life as a planetary force. What a cool idea.
Just last week, however, I saw paper by Samantha Gilbert-Janizek and collaborators that said, “not so fast!”. They built a sophisticated model of the Earth’s evolution from the core (4000 miles to center) to the atmosphere (60 miles up). The simulated version of the Earth had no life on it at all. Then they ran the model for billions of years – including a slowly heating Sun – and the Earth stayed temperate. Instead of life, it was simply the effect of rock weathering that kept the temperature stable. As rocks both form and get weathered away they cycle the greenhouse gas Carbon dioxide (CO2) into and out of the atmosphere.
That was enough to keep Earth habitable for life. But no life was needed.
So, here was my cherished opinion about life and its planetary importance getting trashed. What I should I do? Ignore it? Demand a retraction?
Nope.
Via the very democratic and collaborative process of science, I can take the hard work of my fellow scientists and consider it deeply. Do I think they did a good job? Are there other studies with the same conclusions? If the answer to these questions is yes, then I will have to update my beliefs.
Maybe planets don’t need life to stay habitable. Maybe, I was wrong. Maybe I need to change my mind. We’re not at that point yet but this new paper might be a step in that direction.
Here, however,is the real point. As much as I might be invested in this corner of my belief space, it’s quite stunning to have the world speak in a way that requires me change some of those beliefs. It’s actually kind of refreshing.
So we know it’s possible to change our minds and how to do it. That’s the real value of science.
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PS If you have specific questions or issues you want me to address leave a comment on the website or email me at [email protected]
— Adam Frank 🚀
