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The Boltzmann Brain Paradox: An Animated Thought Experiment About the Hallucination of Reality

You look at a tree. That tree is reality — part of some external reality, and partial to some internal reality of its own. But the tree you see is entirely your mind’s rendition of reality. Consciousness is both the projector and the screen, rendering something you comprehend as a tree. In an absolute sense, then, you can never be sure that the tree exists outside your mind — there can be no evidence of it, for you are both the evidence-gatherer and the evidence.

That is what a thought experiment known as the Boltzmann Brain Paradox explores, inspired by the work of the brilliant and tragic Austrian physicist and philosopher Ludwig Boltzmann (February 20, 1844–September 5, 1906).

Although his theories are now central to modern physics — Boltzmann developed one of its pillars, statistical mechanics, threw an epochal gauntlet to the second law of thermodynamics, provided the current definition of entropy, and mentored the great Lise Meitner — he was so severely criticized for them that his already biochemically precarious mental health (he was afflicted by what we now term bipolar disorder) careened toward the tragic. One late-summer day in his early sixties, while vacationing with his wife and daughter, he died by the breakage of the mind we call suicide, having lived believing that, as mortals, our “destiny is the joy of watching the evershifting battle” and that even though we are each “an individual struggling weakly against the stream of time,” it is in our power to contribute meaningfully to the knowledge and reverie of reality.

With a mind this extraordinary — literally, beyond the ordinary in both its brilliance and its brokenness — Boltzmann reckoned wildly with the nature of reality, the battle for reality, laying the foundation for later questions that eventually took shape in the Boltzmann Brain Paradox:

Complement with the little loophole in the Big Bang and an animated thought experiment about the limits of knowledge and the mystery of consciousness, then revisit the story of the forgotten prodigy William James Sidis, who built on Boltzmann’s legacy to dismantle the dogmas of life and death with his challenge to the second law of thermodynamics.