How Gravitational Waves Forged Human Intelligence
The universe has been whispering secrets through ripples in spacetime for billions of years, and only recently have we learned to listen. When gravitational waves were first detected in 2015, the scientific community celebrated a triumph of theoretical physics—Einstein’s predictions confirmed a century after he made them. But emerging research suggests these cosmic phenomena played a far more intimate role in our existence than anyone imagined. The very waves that allowed us to peer deeper into the universe’s mysteries may have been instrumental in creating the conditions necessary for human intelligence to evolve.
The Golden Discovery That Changed Everything
On 17 August 2017, the Laser Interferometer Gravitational-Wave Observatory (LIGO) detected something extraordinary. Unlike the previous five detections of black hole mergers, this signal—designated GW170817—came from the collision of two neutron stars. For the first time, gravitational waves had a visible counterpart: a brilliant flash of light that telescopes across the globe rushed to observe.
What they witnessed was nothing short of cosmic alchemy. The collision created 200 Earth masses of pure gold, along with other elements. But gold was just the beginning. The cataclysmic merger forged a spectacular array of heavy elements—platinum, uranium, strontium, and crucially for our story, iodine and bromine. These weren’t just any elements; they were the building blocks that would eventually make complex life possible.
For the first time, a freshly made heavy element, strontium, has been detected in space, in the aftermath of a merger of two neutron stars. This detection provided scientists with direct evidence of something they had long theorised: that neutron star collisions serve as the universe’s most prolific heavy element factories.
The Gravitational Courtship of Stellar Titans
To understand how gravitational waves contributed to human evolution, we must first appreciate the cosmic dance that produces these collisions. Neutron stars represent some of the most extreme objects in the universe—stellar corpses so dense that a teaspoonful would weigh as much as Mount Everest. When two of these titans find themselves in orbit around each other, they begin an inexorable spiral dance towards destruction.
As these neutron stars spiraled together, they emitted gravitational waves that were detectable for about 100 seconds. These waves, ripples in the very fabric of spacetime, carry away orbital energy. With each passing moment, the neutron stars draw closer together, their dance growing more frenzied until the final, catastrophic embrace.
When two neutron stars fall into mutual orbit, they gradually spiral inward due to the loss of energy emitted as gravitational radiation. This process, known as orbital decay, is the mechanism by which gravitational waves directly facilitate the creation of heavy elements. Without these spacetime ripples carrying away energy, the neutron stars might never collide, and the universe would remain impoverished of the elements essential for life.
Forging Earth’s Magnetic Shield
The heavy elements ejected from these cosmic collisions didn’t simply drift through space as cosmic debris. They became incorporated into the molecular clouds that would eventually collapse to form new stars and planets. When our solar system began to coalesce 4.6 billion years ago, these neutron star-forged elements were woven into Earth’s very foundation.
The implications for our planet’s habitability were profound. Earth’s magnetic field is generated by electric currents due to the motion of convection currents of a mixture of molten iron and nickel in Earth’s outer core. The heavy elements from neutron star collisions contributed to the formation of Earth’s molten iron core, which acts as a giant dynamo, generating the magnetosphere that protects our planet from harmful solar radiation.
Without Earth’s longstanding, magnificent magnetosphere, we wouldn’t be here nor would any life. This protective magnetic bubble prevents the solar wind from stripping away our atmosphere, maintaining the stable conditions necessary for liquid water to persist on the surface—a prerequisite for life as we know it.
The Tectonic Engine of Evolution
The story doesn’t end with magnetic protection. The heavy elements from neutron star collisions also played a crucial role in initiating plate tectonics, Earth’s geological recycling system. Plate tectonics is the scientific theory that the Earth’s lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago.
This geological activity has been instrumental in shaping the evolutionary pressures that led to human intelligence. A new study links the emergence of new hominin species, expanding brain capacity and early human migration with the appearance of deep freshwater lakes. These lakes, formed through tectonic activity, created the environmental pressures and opportunities that drove our ancestors towards greater cognitive complexity.
The constant reshaping of continents through plate tectonics created isolated populations, spurring evolutionary innovation. Mountain ranges rose and fell, climates shifted, and new ecological niches emerged—all driven by the geological engine powered, in part, by the heavy elements forged in neutron star collisions billions of years ago.
The Biological Necessity of Stellar Gold
Recent research has revealed an even more direct connection between neutron star collisions and human biology. In 2024, a team of researchers from Kings College London, CERN, University of Illinois, and the University of Notre Dame also connected gravitational waves’ role in producing iodine and bromine—two heavy elements that are essential to human biology.
Iodine is crucial for proper thyroid function, which regulates metabolism and brain development. A deficiency during critical developmental periods can lead to severe cognitive impairment. Bromine, while less well understood, appears to play important roles in nervous system function and may be essential for normal brain development.
Without the neutron star collisions that forged these elements, the biochemical foundations for complex nervous systems—and ultimately human intelligence—might never have existed. We are, quite literally, made possible by the universe’s most violent events.
A Universe Fine-Tuned for Thought
The emerging picture suggests a universe intricately connected across vast scales of space and time. The Rare Earth hypothesis argues that conditions needed to ensure the planet has a magnetosphere and plate tectonics are among the crucial factors that make complex life possible. What we now understand is that gravitational waves played a direct role in creating these conditions.
This realisation adds a new dimension to our understanding of cosmic evolution and our place within it. The same fundamental force that Einstein predicted, that LIGO detected, and that continues to carry information across the cosmos about distant collisions, has been shaping the conditions for intelligence since the universe was young.
The Continuing Dance
As of May 2025, GW170817 is the only gravitational wave detection to be definitively correlated with any electromagnetic observation. But as our detectors become more sensitive and additional observatories come online, we expect to witness many more of these cosmic events. Each detection provides another piece of the puzzle about how the universe manufactures the ingredients for complexity and consciousness.
The story of gravitational waves and human intelligence is still being written. When two neutron stars merge, the resultant explosion forms heavy elements — many of which make up our Universe. As we continue to observe these events, we gain deeper insights into the cosmic processes that made our existence possible.
Ripples Through Time
Perhaps most remarkably, this cosmic connection operates across multiple temporal scales. The neutron star collisions that created the heavy elements in our bodies occurred billions of years ago, yet their gravitational wave signatures are only now being detected by our instruments. In essence, we are using the descendants of those ancient collisions—the complex brains they helped make possible—to detect and understand the very processes that created us.
The next time you look up at the night sky, remember that you are witnessing an ongoing cosmic symphony. Somewhere in the distant universe, neutron stars are spiralling towards each other, emitting gravitational waves that will carry away their orbital energy until they collide in a burst of creation. The heavy elements forged in that cosmic furnace will drift through space for billions of years, eventually finding their way into new star systems, new planets, and perhaps new forms of life capable of contemplating their own cosmic origins.
In this grand narrative, gravitational waves are not merely astronomical phenomena to be detected and studied. They are active participants in the universe’s capacity to know itself—cosmic midwives to intelligence, carrying the energy that drives the collisions that forge the elements that build the planets that harbour the life that evolves the minds that can finally hear their ancient song.
We are the universe’s way of listening to its own heartbeat, and that heartbeat is carried on waves of gravity through the fabric of spacetime itself. In learning to detect gravitational waves, we have not just opened a new window on the cosmos—we have discovered the cosmic processes that opened the window of consciousness in the first place.
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Thought for the day:
“Being deeply loved by someone gives you strength, while loving someone deeply gives you courage.”
Lao Tzu
