A billion years ago (well, give or take) in a galaxy far, far away, two black holes performed a cosmic ballet pas de deux. They circled one another, gradually coming closer under the influence of mutual gravity, until they collided and merged together. As a result of such a collision, a colossal release of energy occurred, equivalent to three times the mass of our sun. The convergence, collision and merger of two black holes threw the surrounding space-time continuum into disarray and sent powerful gravitational waves in all directions at the speed of light.
By the time these waves reached our Earth (and it was on the morning of September 14, 2015), the once powerful roar of cosmic proportions turned into a barely audible whine. Nevertheless, two huge machines several kilometers long (detectors of the Laser Interferometric Observatory of Gravitational Waves PIOGV), located in the states of Louisiana and Washington, recorded easily recognizable traces of these waves. On Tuesday, three longtime PIOGV project leaders - Rainer Weiss, Barry Barish and Kip Thorne - received the Nobel Prize in Physics for this achievement.
This discovery has been brewing for a long time, both on the human time scale and on the astronomical clock. Dr. Weiss, Dr. Thorn, and Dr. Barish and colleagues have worked on their project for several decades. Thousands of people working on five continents were involved in the 2015 discovery. This project was an example of a strategic vision of the future by scientists and politicians, which is almost as distant from us as these colliding black holes.
In the late 1960s, Dr. Weiss taught a senior physics course at the Massachusetts Institute of Technology. A few years earlier, physicist Joseph Weber had made the announcement that he had detected gravitational waves using an instrument with aluminum cylinder antennas. However, Weber failed to convince skeptics. Dr. Weiss gave his students a homework assignment to find another way to detect waves. (Students, take a note: sometimes homework is a harbinger of a Nobel Prize.) What if you try to detect gravitational waves by carefully studying the smallest changes in the interference of laser beams that travel along different paths, and then reconnect in the detector?
In theory, gravitational waves should stretch and contract in space, moving through it. Dr. Weiss suggested that such a disturbance should change the path length of one of the laser beams, due to which the two beams will lose synchronization by the time they reach the detector, and from the difference in desynchronization it will be possible to determine the patterns of interference.
The idea was daring and revolutionary. And that's putting it mildly. To capture gravitational waves of expected amplitude using the interference technique, physicists had to detect a difference in distance that was one part in a thousand billion billion. It is like measuring the distance between the Earth and the Sun on the scale of a single atom, while monitoring all other sources of vibration and error that can suppress such a weak signal.
Unsurprisingly, Dr. Thorne, who became one of the Nobel laureates this year, posed the problem as a homework assignment in his 1973 textbook. He led the students to the conclusion that interferometry as a method for detecting gravitational waves is not good at all. (Okay, gentlemen, students, sometimes you don't have to do your homework.) But with a deeper study of this problem, Dr. Thorne became one of the strongest supporters of the interferometric method.
Convincing Dr. Thorn was easier than obtaining funding and attracting students to the work. The National Science Foundation in 1972 rejected Dr. Weiss's first proposal. In 1974 he made a new proposal and received some funding for the design study. In 1978, Dr. Weiss noted in his application for funding: "Gradually, I came to the realization that this kind of research is best done by unquestioning and possibly stupid scientists, as well as young graduate students with adventurous inclinations."
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The scope of the project gradually expanded. The huge arms of the interferometer now had to extend for several kilometers, not meters, and be equipped with the most modern optics and electronics. At the same time, the budget and the research team grew. The implementation of this complex project now required not only a deep knowledge of physics, but also political skill. At some point, attempts to build one of these large detectors in Maine failed due to political rivalries and behind-the-scenes deals of congressional apparatchiks. This taught scientists that there is more interference than laser beams.
Surprisingly, the National Science Foundation approved funding for PIOGV in 1992. It was the most expensive project of the foundation, as it remains to this day. The timing was right: after the collapse of the Soviet Union at the end of 1991, physicists instantly realized that the Cold War arguments in favor of scientific research in Congress were no longer valid.
It was around this time that budget tactics in the United States entered a new phase. Now, when planning long-term projects, it was necessary to take into account the frequent threats of suspension of the activities of state bodies (sometimes they were carried out). This complicated the budgeting situation as the focus was now on short-term projects that promised quick results. If a project like PIOGV were proposed today, it is hard to imagine that it would receive approval.
However, PIOGV demonstrates certain advantages of a long-term approach. This project exemplifies the close relationship between science and education that goes far beyond homework. Many students and postgraduates from the PIOGV team became co-authors of a historical article about the detected waves. Since 1992, almost 600 dissertations have been written within the framework of this project in the United States alone, which were prepared by scientists from 100 universities and 37 states. Scientific research has gone far beyond physics, and now encompasses areas such as engineering and software development.
PIOGV shows what we can achieve by looking beyond the horizon and not getting hung up on annual budgets and reports. By building highly sensitive machines and educating smart and dedicated young scientists and engineers, we can test our fundamental understanding of nature with unprecedented precision. Such efforts often lead to improvements in the technologies used in everyday life: the GPS navigation system was created as part of work to test Einstein's general theory of relativity. True, such unexpected discoveries are difficult to predict. But with patience, perseverance and good luck, we can look into the innermost depths of the universe.
David Kaiser is Professor and Lecturer in Physics and History of Science at Massachusetts Institute of Technology. With W. Patrick McCray, he has edited Groovy Science: Knowledge, Innovation, and the American Counterculture.