Rebecca Schembri, Harvard University Extension School, March 8, 2021
In 1781, a philosopher named Immanuel Kant published Critique of Pure Reason, a book that made the same argument in its thesis as in its antithesis. Not the workings of a madman, it explored mind-boggling hypotheses, the origins of the universe in relation to time and space. His quest was agonizing, a fascination with truth that consumed thought. Humans have always looked to the sky with unanswered queries, determined to understand what exists in the outer realms; over the centuries, the study of science ousted philosophers and theologians from explaining the cosmos as each astronomer, mathematician, and physicist built upon the foundation of facts left by another. Such spirit of growth has crossed thousands of years to culminate to the knowledge humans have today about what the universe is, how it works, and why it matters to Earth’s inhabitants.
Some heed the calling, giving an entire generation of study to the soul-binding quest of scientific truth, recognizing that, in scientist Stephen Hawking’s words, “[t]o confine [one’s] attention to terrestrial matters would be to limit the human spirit.” This unarguable mission of dutifully learning, practicing, and calculating upon the theories of the past is what makes human discovery of the cosmos a team effort, impossible without the studious and lifelong pains of inquisitive minds throughout time. In a day when space travel is occurring and plans for human settlement upon extraterrestrial bodies have been conceived, no one person can take credit for sending rockets into space or for setting up basecamp on Mars; missions such as reaching Jupiter’s moons and journeying into the unknown will take the cumulative effort of tens of thousands of thinkers. Even if artificial intelligence overcomes scientific study, serving in place of humans, the universal contributions made by scientists from the beginning of civilization to the present day will be responsible for it.
Although thousands of years ago Chinese and Middle Eastern peoples intently studied and recorded the cosmos, the scientific contributions of Greek philosophers paved the way for modern science by using mathematical models to explain what they knew. In ancient Greece, Aristotle taught three dimensions while quoting Pythagoras who preceded him by 200 years. Unpublished for many centuries, Aristotle’s 340 AD book, On the Heavens, showed he had made the first arguments for a spherical Earth and for orbiting planets, laying a foundation for Ptolemaic teaching. Ptolemy, a Greek Egyptian centered in Alexandria in the second century, created the cosmic model, which, though flawed, pleased the Catholic church, who accepted it as being in alignment with Scripture, since, according to Hawking, “it had the great advantage that it left lots of room outside the sphere of fixed stars for heaven and hell.” Being in alignment with the Church or government usually meant, throughout history, that an astronomer could keep his or her head and continue important research.
Over a millennium later, sixteenth-century Polish astronomer Nicolaus Copernicus faced this dilemma head-on when he realized the Ptolemaic model was erroneous. As he introduced findings for a Sun-centric, rather than Earth-centric, cosmic system, he did so anonymously to avoid backlash from religious authorities. His book, On the Revolutions of the Heavenly Spheres, objected to Ptolemy’s circular orbits model and sparked a revolution that, according to scholars in The Cosmic Perspective, “laid the foundation for the rise of our technological civilization.” Understanding that planets orbit around the sun allowed the next scientists to affirm the theory, grow on it, and reach new expanses in cosmology. When Johannes Kepler of Germany came along a century later, Copernicus Theory was still being examined. Kepler discovered, “almost by accident” that planets’ orbits are elliptical, rather than circular. This led to the astronomer’s Three Laws of Planetary Motion—his greatest contributions to modern science. Because of Kepler’s rules, scientists can determine a planet’s distance from its sun, and its orbital speed.
Soon after came the Italian Galileo Galilei, who was, in Dr. Stephen Hawking’s words, “perhaps more than any other single person, …responsible for the birth of modern science.” He built upon Copernicus’ belief that the sun was the center of the system, keeping his loyalty private until he found actual evidence supporting the theory. The astronomer took great pains to honor scientific discovery, writing: “To this end I have taken the Copernican side in the discourse, proceeding as with a pure mathematical hypothesis and striving by every artipee to represent it as superior to supposing the earth motionless.” Although he eventually garnered public support for the heliocentric model, scholars vetted against him, tragically “seeking to persuade the Catholic church to ban Copernicanism.” In a faithful gesture to stay alive while defending science at excruciating pains, the great astronomer kept his best work for last, ushering in the “genesis of modern physics” in a book that he had smuggled out to be published upon his death: Two New Sciences. A wise man to recognize his place in power, Galilei was never harmed for his beliefs, forgoing the trap of ego and pride and remembering that the Church had burned Astronomer Giordano Bruno at the stake for promoting scientific advancement.
Succeeding Galileo was mathematician and Englishman Sir Isaac Newton whose findings have deservingly earned the respect of the mathematical community for the past hundreds of years. His book, Philosophiae Naturalis Principia Matematica, was, according to Hawking, “probably the most important single work ever published in the physical sciences.” Subrahmanyan Chandrasekhar wrote that it had “depth and rare perception” and that Newton’s offering of space and time theory, and the mathematical calculations to illustrate them, enhanced the work of physics for centuries to come. After Newton, research on black holes began to surface. In 1783, U.K. philosopher John Michell published a paper explaining that a star’s gravity could overcome its emittance of light. Michell’s contemporary, Frenchman Marquis de Laplace, made a similar independent discovery, publishing his findings in Exposition du Systeme du Monde, noting that “…any star of the same density as the sun and with a diameter 250 times greater will capture the light it radiates.” The time had come to know about black holes. As both researchers used current advancements in astrophysics, they were able to glean the same conclusions from their studies at the same time.
A few decades later, German astronomer and mathematician Friedrich Bessel used the discovery of stellar parallax successfully, breaking through the impossibility of mapping the distance of far-off stars. Prior to that, Sir Arthur Eddington made advances that garnered evidence for Albert Einstein’s coming theory of relativity. Another master building upon the foundation of another, and preparing for another to build upon his, he was member to a finite community. Hawking recounts that “a journalist told Eddington in the early 1920’s that he had heard there were only three people in the world who understood general relativity. Eddington paused, then replied, ‘I am trying to think who the third person is'” (emphasis added).
The few masters in the world knew of each other, heard of each other, learned from each other, and helped build the future together. It was twentieth-century Indian American astrophysicist and Nobel Prize winner, Subrahmanyan Chandrasekhar who discovered cold stars, calling them “white dwarfs.” He also interpreted Newton’s Pricipia Matematica, clarifying the “convoluted style Newton had to adopt in writing his geometrical relations and mathematical equations in connected prose.” ‘Chandra’, as he was nicknamed, called his effort: Newton’s Principia for the Common Reader, “…an undertaking by a practicing scientist to read and comprehend the intellectual achievement that Principia is.” By paraphrasing the book upon serious and successful use of Newton’s formulas, he formed a bridge to the next generation of scientists, giving them a tool better equipped for modernity. Chandra’s discovery, on the other hand, “calculate[ed] that a cold star of more than about one and a half times the mass of the sun would not be able to support itself against its own gravity,” taught Hawking. This rule became known as the Chandrasekhar Limit. Replicating, again, the same discovery at the same time, Russian scientist Lev Davidovich Landau made a similar claim to Chandrasekhar’s, identifying neutron stars. The calculations of both scientists formed part of the doctrine of modern astronomy.
Years earlier, German Albert Einstein had proposed his discoveries in Cosmological Considerations on the General Theory of Relativity. His breakthrough research suggested not only the effect of gravity on light, but a genius mind, assuring that his contributions to humanity would be remembered among the greatest. Not uncommon during the wars of the 20th century, many scientists were recruited to postpone their work and assist the government in developing bombs for the military, especially in World War II. Einstein, who, because of the war was “divided between politics and equations,” was once offered the Israeli presidency because of his brilliance and his activism. Originally a pacifist, he opposed violence since it “wastefully” consumed human life; arguing for anti-war measures, Einstein contributed to international diplomacy efforts promoting peace. However, Hawking writes, “[i]n the face of the Nazi threat, Einstein renounced pacifism, and eventually, fearing German scientists would build a nuclear bomb, proposed that the United States should develop its own.” He was not alone in his conflicting personal beliefs about violence, American Physicist Robert Oppenheimer gave up his work making weapons for America in the Cold War and quit, shuddering at the idea of using his science for the mass destruction of humanity.
By the 1920’s, American Edwin Hubble’s work on Cepheid stars had been published, explaining spiral nebulae and his calculations on the Andromeda Galaxy. Hubble opened the eyes and telescopes of astronomers worldwide, as he showed that many galaxies exist in the universe. He explained how to measure a galaxy’s distance by using Doppler lines, producing “very convincing evidence,” Dr. Hawking writes, “that the relationship is indeed linear and hence…a galaxy’s redshift is directly proportional to its distance.” Hubble’s work, The Realm of the Nebulae, explored his thoughts on astronomy outside the Milky Way. After him came Stephen Hawking, who was one of America’s brightest minds into the new millennium. A humorous fellow, the theoretical physicist, cosmologist, astrophysicist, professor, and author worked to build upon Einstein’s principles with quantum mechanics and argued for the presence of black-body energy, known later as “Hawking Radiation.”
Although most astronomers today may now publish their findings freely, another kind of injustice still existed until this decade. Not to be upstaged by the accomplishments of renowned male scientists, perhaps the most astounding contributions to modern-day astrophysics were made by the team of African American females who inspired the movie Hidden Figures, the story of how the United States won the 1960’s space race, putting man into orbit by calculations performed from women who were prevented by law to work openly—an untold history of segregation and gender discrimination. Although many scientists are only famous within their industry, some, like these women, become public names. Likewise, with his television show Cosmos enlightening the general public on the marvels of outer space in the 1980’s, physicist Carl Sagan finished out his career in the public eye. Celebrity astrophysicist Neil deGrasse Tyson revisited the program decades later, bringing joy for the universe into family living rooms across the world. Today, innovators like Elon Musk are running the journey into space and succeeding. With private enterprise supplying rockets, spaceships, and science, the National Aeronautics and Space Administration has pared down its production and begun to team with aerospace companies such as SpaceX, Blue Origen, and Boeing. These moves publicly glorify space travel, as the younger generation worldwide popularizes casualwear with NASA logos on their T-shirts, hats, and jackets.
Although the spotlight is encouraging, the study of science is not an easy feat. To declare a theory is only to present evidence of something that, upon the presentation of different evidence, can be made obsolete, as the next set of wise men or women make new and more concise calculations. This is part of the realm, and those who would criticize the mission, saying space exploration is a luxury, need refrain, as Galileo sneered:
“Complaints were to be heard that advisers who were totally unskilled at astronomical observations ought not to clip the wings of reflective intellects by means of rash prohibitions…These men indeed deserve not even that name, for they do not walk about; they are content to adore the shadows, philosophizing not with due circumspection but merely from having memorized a few ill-understood principles.”
The astronomer’s work was scrutinized and controlled by people who could not accept the truth because they did not understand how important the truth was. Innovators like Musk are privy to this, as they honor the achievements of science and adhere to them faithfully, despite all odds, working for a future that does not belong to them, but to the survivors of climate change, overpopulation, asteroid impact, or nuclear fallout on Earth—the cataclysmic threats humanity is facing over the next two generations and beyond.
Had Aristotle known, or hoped, that his work would be published hundreds of years past his time, or Galileo, when he submitted to the Church, as he whispered what he could not deny, that the Earth moves, if he knew that four hundred years later he would be exonerated, having made the greatest contributions to astronomy of his millennium, it would have brought them both the comfort they sacrificed when they worked in obscurity for the good of humankind. As with Katherine Johnson and her segregated colleagues, kept hidden for sixty years—often contributions made by scientists are not celebrated until after their time; they are simply a formula passed on to the future. Galileo understood the importance of historical study as support for the new, writing, “I hope…to reveal many observations unknown to the ancients.” He built upon the work of his elders, who with each generation of scientists had practiced reliance on the last. Chandrasekhar held the same discipline, moving that he would be “quoting from the masters of earlier centuries” in the publication of his book on Newton, who had preceded him by three centuries. He also understood the necessity to share information, a custom now mirrored in international outer space treaty law.
What then, is the future of space after thousands of years of incremental discovery? With the advent of supercomputers and artificial intelligence, knowledge of the universe has grown exponentially. As scientists plug their formulas into machines, calculations can be performed at speeds impossible to human thought or action. Perhaps the last great accomplishment of astrophysics is on the horizon: computers that eliminate the need for human discovery. Shocking and painful, yet victorious, this “benching” of the professional will also be attributed to science— “despite the vastness of the [cosmos],” wrote Stephen Hawking, “there is a sense in which we remain significant: we can still be proud to be part of a species that is working all this out.” To replace the scientist with his or her own self-perpetuating, created intelligence will be the greatest advancement of all and something to deeply marvel over. As Galileo taught: “…there proceed from this clime not only dogmas for the welfare of the soul, but ingenious discoveries for the delight of the mind as well.” After all, “an equation is something for eternity,” said Einstein. A testament from them both, and likely with the nods of astro-scientists past and in perpetuity—the study of space is godly, liberating the human spirit and filling its soul with gratitude and wonder as, more and more, through the study of the cosmos, it becomes clearly evident that life on Earth, and human life, is miraculous; a severe improbability; and the sobering, wondrous blink of an eye that took not only billions of circumstances to occur, but myriads of bright minds to recognize.