Image of a gravity wave rippling over a cloud.

What good is a gravity wave, anyway?

Rik Williams
Feb 17, 2016

On February 11, 2016, the LIGO Collaboration announced the first direct detection of a gravitational wave signal, likely caused by two black holes merging in a distant galaxy.

It's hard to overstate how profound this finding is. Other types of signals have long been familiar to us: after all, we've been detecting light (a manifestation of the electromagnetic force) with our eyes since our species came into being. Similarly, we're intimately familiar with the sound waves that propagate through matter. In modern times, we've built scientific instruments to explore the natural world that are increasingly sensitive to light and sound. But the LIGO announcement demonstrates the first incarnation of a fundamental new capability, a device that can sense vibrations in spacetime itself.

Numerous media reports on the discovery have noted that it came 100 years after Einstein released his seminal General Theory of Relativity, the mathematical formulation that first predicted gravitational waves. Since so many experiments have confirmed other predictions of this theory, in some sense the existence of gravitational waves was a foregone conclusion; in fact, we've already seen indirect evidence of them for years. Even so, after decades of knowing gravitational waves as a physical abstraction, actually seeing the waveforms plotted out in the LIGO press release was nothing short of exhilarating.

Gravity Wave. LIGO

In a more troubling juxtaposition, the LIGO discovery was also announced the day after the House of Representatives passed H.R. 3293, the Scientific Research in the National Interest Act. This bill would limit the National Science Foundation to funding research proposals that are deemed "in the national interest," as defined by seven criteria. Although the criteria are broad, their interpretation is ultimately up to Congress, not scientific peer reviewers. H.R. 3293 may therefore represent another step toward politicians, rather than scientists, becoming the arbiters of which research projects are worthy of funding. A step toward limiting scientific inquiry to projects with predictable, economically valuable results.

In 1915, relativity was a remarkable theory with no clear relevance to the national interest. But in the intervening century it has led to countless applications, from the realization that small amounts of matter could be converted to enormous amounts of energy (E=mc2) to enabling the precise timing measurements that GPS navigation relies upon. Similarly, while gravitational waves likely won't play a role in our day-to-day lives, LIGO's unfathomable precision required a series of engineering feats and innovations, training hundreds of STEM professionals in the process. Society will reap the technological and human capital benefits of LIGO for decades to come. And maybe at some point in the distant future, a practical use for gravitational radiation will indeed come to fruition.

When confronted with questions about why tax dollars should pay for basic research, scientists often revert to past applications. For instance, as an astronomer, I've given spiels about my field's influence on digital photography, optics, big data, radio communication, image processing, and so on. But this is a trap, since the natural follow-up question is: "So what will your research lead to?" Of course, this can rarely be predicted, yet H.R. 3293 is predicated on the notion that it can. Restricting scientists to research with tangible short-term outcomes would be catastrophic, removing the impetus for conducting open-ended investigation, for delving into the hows and whys of natural phenomena simply because they're there.

As scientists, we need to be crystal clear on this: Expanding the base of human knowledge IS in the national interest.


Image Credit: LIGO Collaboration and NASA

Rik Williams

Rik is a data scientist on the Policy, Research and Economics team at Uber Technologies, Inc. Prior to joining Uber, he spent many years doing research in observational astrophyics and served two years as a AAAS Science & Technology Policy Fellow at USAID.


This blog does not necessarily reflect the views of AAAS, its Council, Board of Directors, officers, or members. AAAS is not responsible for the accuracy of this material. AAAS has made this material available as a public service, but this does not constitute endorsement by the association.

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