My interest in science predates any formal training. Like many children, I was drawn early to popular science books and magazine articles – not for equations or technical mastery, but for the sense that the universe was intelligible, that patient thought could prise open even its most forbidding mysteries.
Long before I understood what spacetime meant, I knew that science was a conversation across generations, in which ideas whispered in one century might be heard clearly in another. Over the years, following developments in astronomy, physics and biology became a habit. That is why January 2016 stands out so sharply in memory.
When news broke that gravitational waves had been directly detected, the reaction was not merely admiration but astonishment. This was not just another discovery to be logged and explained away. It felt momentous in a deeper sense – an event that stitched together childhood wonder, intellectual patience and human ingenuity. Something predicted a hundred years earlier, often dismissed as unobservable, had finally announced itself.
Ten years later, the anniversary of that announcement is a fitting moment to reflect on why it mattered then, what it has changed since, and what lessons it holds – especially for societies that struggle to think beyond the immediate horizon.
The idea of gravitational waves originated in Albert Einstein’s general theory of relativity, published in 1915. In this framework, gravity is not a force acting across space but the curvature of spacetime itself, shaped by mass and energy. When massive objects accelerate – two stars orbiting each other, or black holes spiralling towards collision – that curvature should ripple outward. These ripples, travelling at the speed of light, are gravitational waves. They carry information not about surfaces or radiation, but about motion and mass in their most extreme forms. Einstein was famously uncertain about their physical reality. Although his equations allowed such waves, he doubted they could ever be detected.
Gravity, after all, is astonishingly weak. By the time gravitational waves reach Earth from even the most violent cosmic events, they distort spacetime by less than the width of a proton. For decades, gravitational waves remained suspended between elegant mathematics and experimental despair. Attempts to detect them in the mid-twentieth century generated controversy and disappointment, and the field acquired a reputation for chasing phantoms.
What changed was not a sudden flash of insight but the slow accumulation of enabling technologies. Lasers became stable enough to serve as precision rulers. Vacuum systems improved to near perfection. Materials science produced mirrors of extraordinary smoothness. Seismic isolation techniques learned to tame the Earth’s constant restlessness. At the same time, computing power expanded dramatically, making it possible to analyse torrents of noisy data.
Out of this convergence emerged the Laser Interferometer Gravitational-Wave Observatory, known universally as LIGO. The basic concept behind LIGO is simple. A laser beam is split and sent down two perpendicular arms several kilometres long. The beams bounce off mirrors and recombine. If a gravitational wave passes through, it slightly alters the relative lengths of the arms, producing a detectable interference pattern.
Achieving the required sensitivity, however, took decades. Initial configuration detected nothing. Only after extensive upgrades – painful, expensive, and publicly scrutinised – did it reach the sensitivity needed to probe the universe meaningfully. Then, in September 2015, almost as soon as the upgraded detectors began operating, a strong signal swept through them. When the announcement came in January 2016, it was clear that this was no marginal result. Two black holes, dozens of times the mass of the Sun, had merged over a billion light-years away. The resulting waveform – a rising ‘chirp’ followed by a sharp cutoff – matched theoretical predictions with uncanny precision.
For general relativity, this was vindication in the most extreme conditions yet tested. Over the ensuing decade, that vindication has been repeated many times. Dozens, then hundreds, of gravitational-wave detections have confirmed that gravity behaves exactly as Einstein predicted, even in the violent strong-field regime near merging black holes. Gravitational waves travel at the speed of light. Black holes ring down in precisely the manner the theory prescribes. For physicists hoping for cracks that might point towards new physics, the results have been conservative. For science more broadly, they have been a testament to the durability of deep theoretical insight.
Astrophysics, however, has been transformed. Before 2015, black holes were known largely through indirect evidence – X-rays from accreting matter or the orbital motions of nearby stars. Gravitational waves allowed them to be observed directly, not as images but as events. One immediate surprise was abundance. Binary black-hole systems turned out to be far more common than expected, and many involved black holes significantly heavier than models had predicted. This forced a re-evaluation of stellar evolution, particularly in low-metallicity environments where massive stars lose less mass before collapse. The universe, it turned out, had been quietly producing heavyweight black holes in large numbers.
Neutron stars added another dimension to the story. In August 2017, detectors observed the inspiral of two neutron stars, followed by electromagnetic signals across the spectrum. This multi-messenger event confirmed long-standing theories that such mergers are factories for heavy elements. Gold, platinum and other precious metals were forged in the neutron-rich debris. In a single observation, gravitational physics, nuclear chemistry, and cosmic history converged. The atoms in everyday objects were linked decisively to distant stellar catastrophes. That same event opened a new path in cosmology. Gravitational waves encode distance directly, without the complex calibrations required by traditional astronomical methods.
Combined with redshift measurements from telescopes, they offer an independent estimate of the universe’s expansion rate. Although this ‘standard siren’ approach has not yet resolved the tension between competing measurements of the Hubble constant, it has sharpened the debate and underscored the importance of independent checks. Technological progress has continued relentlessly. Additional detectors have improved localisation of sources. Signals can now be identified within minutes, enabling rapid follow-up observations. Machine-learning algorithms sift through torrents of data, separating genuine cosmic events from terrestrial noise.
New approaches are probing other frequency ranges. Beyond astronomy, gravitational waves have become tools for fundamental physics. They constrain alternative theories of gravity, limit the existence of extra dimensions, and test exotic ideas about the nature of spacetime. So far, the results have been reassuringly orthodox. No dramatic deviations have appeared. Yet in science, absence is itself evidence. Each non-detection narrows the landscape of plausible theories and disciplines speculation.
Ten years on, the gravitational-wave story also prompts an uncomfortable comparison between what societies choose to celebrate and what they choose to invest in. Pakistan today frequently boasts of advances in defence technologies. These achievements are presented as markers of national strength and scientific prowess. Yet they rest on a narrow conception of security – one that privileges hardware over human capacity, secrecy over openness, and spectacle over substance. Gravitational-wave astronomy offers a counter-model. Its success did not come from militarised urgency or strategic rivalry, but from patient public investment, international collaboration and a commitment to knowledge whose benefits were uncertain for decades.
The technologies it nurtured now spill over into medicine, communications, climate science, and industry. Its dividends are civilian by design. No single country owns them. For Pakistan, the lesson is not naive pacifism, nor the abandonment of legitimate security needs. It is proportionality. A state that can marshal resources for increasingly sophisticated weapons systems can also choose to invest far more ambitiously in public-benefit science: universities equipped for serious research, laboratories that reward curiosity rather than compliance, and educational systems that teach students how to think rather than what to memorise.
True national resilience in the 21st century will depend less on deterrence postures and more on scientific literacy, technological adaptability and institutional trust. Defence technologies promise safety through exclusion and threat; public science promises security through capability and inclusion. Gravitational waves remind us that the most transformative discoveries often arise not from fear of enemies but from confidence in reason. They were not built to intimidate rivals or signal power. They were built because someone believed that understanding the universe was a public good.
As Pakistan debates its future priorities, the tenth anniversary of gravity’s whisper offers a quiet but profound signal. Nations that invest primarily in instruments of destruction may achieve momentary prestige. Nations that invest in shared knowledge build endurance.
The writer is dean of the faculty of liberal arts at a private university in Karachi. He tweets/posts @NaazirMahmood and can be reached at: [email protected]
