A Netflix documentary raises existential questions about the fate of life and intelligence in an expanding universe

In a thought-provoking documentary titled “A Trip to Infinity,” directed by Jonathan Halperin and Drew Takahashi, Janna Levin, a cosmologist from Barnard College, makes a profound statement that echoes through the minds of viewers. “There will be a last sentient being, there will be a last thought,” she declares, leaving a lasting impact on the audience.

For those in attendance during a recent screening of the film, including myself, Levin’s words struck a deep chord, stirring feelings of sadness and loneliness. It was an idea that shattered any illusions of intellectual peace I had cultivated about our shared cosmic predicament. The premise is grim but impossible to ignore: if our understanding of physics and cosmology holds true, life and intelligence are destined for extinction.

Yet, Levin’s angle introduced a new perspective, one that had eluded my previous contemplations. Somewhere in the vastness of the future universe, there will exist a point in time where the last sentient being will reside—a being whose thoughts will mark the culmination of consciousness. The significance of this finality, regardless of the profundity or mundanity of that ultimate thought, will vanish into a silent void. Even the memory of iconic figures like Einstein, Elvis, Jesus, Buddha, Aretha, and Eve will fade away, while the physical universe continues its lonely voyage of separation for countless eons.

What will this last thought be? A profound pearl of wisdom or a mere expletive? The question remains unanswered.

How did humanity find itself entangled in this perplexing predicament? The universe as we know it ignited in a blazing burst approximately 13.8 billion years ago and has been expanding ever since. Astronomers once debated whether this expansion would continue indefinitely or eventually collapse into a cataclysmic “big crunch.”

In 1998, everything changed. Astronomers made a groundbreaking discovery: the cosmic expansion was accelerating, driven by an enigmatic force known as “dark energy.” This force, intertwined with the fabric of spacetime, pushes the universe apart with increasing strength as it grows larger. Strikingly reminiscent of the cosmological constant proposed by Einstein—a concept initially deemed a mistake—this dark energy now threatens to disrupt the foundations of physics and the very fabric of the universe.

If this dark energy prevails, distant galaxies will eventually recede at such incredible speeds that they become invisible to us. With the passage of time, our knowledge of the universe will diminish. Stars will die, never to be reborn. Our existence will mirror that of an inverted black hole, ceaselessly drawing matter, energy, and information over the horizon, never to return.

Of course, one may argue that it is premature to assert a definitive fate for the universe. New revelations in physics may unveil unexpected escape routes. Perhaps dark energy is not constant; maybe it will reverse its course, bringing about a recompression of the universe. In an email exchange, Michael Turner, the renowned cosmologist who coined the term “dark energy,” suggests that “Lambda,” symbolizing Einstein’s cosmological constant, would be the most uninteresting answer to the dark energy puzzle.

For now, however, the prospect outlined above looms over us, casting its shadow on the future.

Our destiny is sealed, a billion years from now, when the sun’s relentless heat evaporates Earth’s oceans. Several billion years later, the sun itself will perish, engulfing our planet and any remnants of our existence in a fiery demise.

Escape to space is futile. Galaxies themselves will ultimately succumb to the relentless pull of black holes in approximately 10^