Smoke and Mirrors

What’s wrong with this picture? A billion years ago, two Black Holes collided in outer space more than a billion light years away from the Earth. In 1916, Albert Einstein, the greatest physicist of all time, predicted, as a corollary to his general theory of relativity that this collision would cause ripples in “space-time” — his term for the melding of the concepts of space and time – which he termed “Gravitational Waves.” A hundred years later, astronomers from the California Institute of Technology and the Massachusetts Institute of Technology claimed to have found evidence corroborating the existence of these black holes and gravitational waves, whose importance stemmed in part by their leveraging off Einstein’s imprimatur.

To ferret out the evidence to support their claim, these teams of scientists relied on a tool known as LIGO, the Laser Interferometer Gravitational – Wave Observatory. It consists of two huge sets of vacuum-filled mirrors, each four kilometers long and outfitted with powerful lasers. One set is located in Hanford, Washington, and the other is in Livingston, Louisiana. They were designed to detect gravitational waves by searching for a very faint “chirp” about a second long from the passing of an infinitesimally small gravitational wave, while at the same time filtering out the extensive amount of background noise in the form of interstellar dust, known as Cosmic Microwave Background Radiation. Since the origin of these waves was so distant from Earth, the astronomers reasoned that the evidence would just be reaching us now. The LIGO mirrors were funded by the National Science Foundation for a cost of around a billion dollars (isn’t it interesting how often that number “a billion” crops up in this narrative?) The website Space.Com reported that the deeper significance of the discovery of gravitational waves is that it is the “smoking gun” of the “Big Bang,” the scientific alternative to the creation myth recounted in the Book of Genesis in the Bible.

Black holes are formed in space by objects whose gravity is so dense that no light is able to escape them. As a result, they are not directly observable, but their existence may be inferred from their effect on other celestial bodies such as stars or planets. These black holes are so massive that they typically measure many multiples times the mass of our sun. In the case of the two black holes in question, the story goes, they were attracted not to any planets or stars, but to each other, and they circled one another many times, at ever increasing speeds until they crashed together to release of an amount of energy comparable to that of many atomic bombs.

All research consists of two components: the development of a reasonable theory to explain the phenomena in question, and the design of empirical tests to see if the observed evidence is consistent with the hypotheses implied by the theory. There are several generally accepted criteria with which to evaluate the validity of any scientific research findings. With regard to the theoretical component, it is important to be aware that the plausibility of the conclusions is not necessarily one of these requirements. Many now well-accepted ideas that comprise our understanding of how the world works began as ideas that were certainly counterintuitive. It is also necessary to bear in mind that empirical results that are not grounded in a theoretical foundation constitute little more than a fishing expedition and are therefore to be rejected. Having said this, however, there is still a world of difference between a counterintuitive theory and a collection of tall tales. Good theory must possess the qualities of logical consistency and reasonableness of assumptions. On both counts the LIGO adventure fails as adequate theory. It simply does not make sense, and it rests on a series of arbitrary and unobservable assumptions.

With regard to the empirical side of things, the LIGO efforts are also sadly lacking. An important concept in scientific research is the principle of replication: Can the researchers perform the same experiment under the same initial conditions at different points in time or on different data samples at the same point in time, and obtain the same result. The LIGO researchers apparently detected a second “chirp” a few months after the first one, and they claim that they expect to discern more of them more frequently in the future (in recognition of the importance of the replication principle), but their actual achievements on this score to date have not been forthcoming.

Perhaps an even more serious deficiency of the LIGO findings is the failure to determine an appropriate standard against which to measure the findings’ level of significance. This requirement is especially crucial in light of the three properties that characterize the nature of the data: they originate long ago, they are far away, and they are very small (less than- one-one thousandth the width of a single proton). Under these circumstances, it is a fortiori true that without such a standard, the researchers could easily misread the data, and either incorrectly conclude that they had detected a gravitational wave which wasn’t really there (a false positive), or they could wrongly infer that there wasn’t a gravitational wave when indeed there was (a false negative). The reason these mistakes could occur is that the researchers are actually sampling from a probability distribution characterized by its mean, or central tendency, and its standard deviation, or degree of variability. Only when the observation is a conservative number of standard deviations from the mean of the distribution can the researchers have confidence that they are measuring a real phenomenon and not just an optical, or in this case an auditory, illusion. With the acknowledged extensive amount of Cosmic Microwave Background Radiation present in the data, this oversight reflects an inexcusable inattention to detail.

One of the three lead researchers on the LIGO project boasted, “We did it” after hearing the first chirp and then “We did it again” after the second one. News reporters picked up on this theme and expressed surprise when this year’s Nobel Prize in Physics was awarded a team of three Topologists instead of to the LIGO team, almost as though this oversight were a direct denial of Einstein’s genius and an affront to his memory.  Just for the record, though, no one should be questioning Albert Einstein’s place in the pantheon of individuals who have made important contributions to our understanding of the nature of the universe in which we live and our place in it. In his role as a discoverer of truth, it is no surprise that he is revered as significant, in the sense that he is remembered in history for his contributions long after his death by people who did not know him personally. He is best known as the author of his theory of general relativity, of which the material on Gravitational Waves was something of an afterthought. Furthermore, the shoddy work of the LIGO team was unworthy of Einstein’s memory.

Although the theory of general relativity is best known for its famous conclusion that the amount of energy released by a phenomenon can be measured by the product of its mass, or absolute size, and the square of the speed of light, or 186,000 miles per second (E=mc2), this popular shorthand fails to convey the intuition underlying Einstein’s seminal idea. Perhaps, examples from the following two thought experiments will better illustrate what Einstein was after: In the first case, imagine an observer is sitting in a stationary railroad car while the train on the other track is traveling in the opposite direction at high speed. At the moment the other train passes in the opposite direction, the stationary observer cannot distinguish if he has seen the train in which he is seated moving forward or if he has not moved and he only imagines the forward movement because of his vantage point relative to the other train. A similar thought experiment is as follows: Imagine someone is standing in an elevator and suddenly the force of gravity causes the car to drop precipitously. Relative to his stationary position, he cannot tell the difference between what has actually happened and the opposite sensation of accelerating upward in the elevator car.

These counterintuitive ideas were first explored in Einstein’s 1905 paper “On the Electrodynamics of Moving Bodies,” which, interestingly, formed the foundation for his more limited Theory of Special Relativity. Some of the building blocks of this theory may not seem surprising to people today (e.g., two events, viewed simultaneously by one observer, may not be simultaneous for another observer if the observers are moving relative to each other.) Nevertheless, some of the implications of this theory are not so intuitive: Time dilates, so that moving clocks are measured ticking more slowly than an observer’s stationary clock, and length contracts, so that objects are measured as being shorter in the direction in which they are moving.  These concepts were in stark contradiction to those of classical mechanics such as those espoused by Isaac Newton.

In conclusion, I hope I have made a convincing case for three claims: First, Albert Einstein was unquestionably a genius. Second, relative (no pun intended) to his other work, his thoughts on gravitational waves bordered on the trivial. And third, the LIGO attempts at empirically testing that work are primitive at best. My recommendation is that the LIGO astronomers should return to school for refresher courses in Basic Statistics and Logic 101.


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