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An International Cosmic Observatory Launches a New Field of Physics

By Maria Spiropulu

I started writing this some time before the Laser Interferometer Gravitational-wave Observatory (LIGO) discovery announcement (see Gravitational waves article) and my main theme was the excitement and challenges of seeding new international science projects around the world. In addition, I was interested in probing existing models of international collaboration and in discussing the impact of global science engagement, both in terms of knowledge advancement and in terms of accelerated development and growth of societies worldwide. But after February 11, I decided to change my focus. I’ll explain why later in the article.

The science communities across the globe have already established Brobdingnagian projects – immense in financial investment, scale, people and countries involved, and in overall complexity. In 2012 we witnessed an example of an unprecedented science effort bear fruit with the fundamental discovery of the Higgs boson at the LHC. It is important to investigate and study how such projects are envisioned, designed, built, and run on different continents, countries, planets — or outer space for that matter, with the participation of thousands of people and hundreds of nations and governments.

We started a very productive discussion at the invited sessions of the APS Forum on International Physics at the April Meeting 2015, where we explored big science partnerships around the world with a focus on high energy physics, nuclear physics and energy, astronomy and cosmology, and last, but by no means least, gravity. The discussion will continue again this year at the Forum’s sessions in the 2016 March and April meetings.

However, on February 11, a monumental discovery was announced: the observation of gravitational waves at LIGO. As a result, I felt compelled to take this great opportunity to reflect on how the unachievable, the impossible, the unthinkable, the Mars-shot in science, is actually carried out and accomplished in the context of international collaboration.

When we talk about LIGO we refer actually to two things: the LIGO Scientific Collaboration (LSC), and the LIGO Laboratory. The LIGO Laboratory is jointly managed by Caltech and MIT and operates the LIGO facilities: the twin interferometers that constitute the gravitational wave observatory at Hanford, Washington, and Livingston, Louisiana. They are funded by the U.S. National Science Foundation (NSF), and were conceived, built, and operated by Caltech and MIT.

Advanced LIGO — a major upgrade to the sensitivity of the instruments compared to the first generation LIGO detectors — began scientific operations in September 2015. Funded in large part by NSF, with contributions from the Max Planck Society in Germany, the Science and Technology Facilities Council in the UK, and the Australian Research Council, Advanced LIGO led to the discovery of gravitational waves. The mission of LIGO was always to open a new field of experimental science: that of gravitational astronomy. On September 14, 2015, LIGO obtained compelling evidence that they have done just that.

But the experimental facilities are only part of the story. LSC is responsible for extracting the science (data analysis strategies, goals, timelines, results dissemination, education and outreach, and so on) and identifying priorities for R&D and improvements of the observatory. It comprises 945 members from 15 countries (United States, United Kingdom, Germany, India, Australia, Russia, Korea, Italy, Hungary, Brazil, Spain, China, Taiwan, Canada, and Belgium). The LSC governance principles include two elements worth noting: (i) no individual or group will be denied membership on any basis except scientific merit and the willingness to participate and contribute, and (ii) member agreements describe scientific, not financial commitments.

The collaboration is poised to continue growing, as LIGO is only the first node on a powerful network of gravitational wave detectors worldwide. The network includes GE0600 in Germany, the Virgo detector in Italy, and KAGRA in Japan. Following the February 11 announcement, the Indian Cabinet, chaired by Prime Minister Modi, has granted in-principle approval to the Laser Interferometer Gravitational-wave Observatory in India, which will be the sixth node of the international gravitational wave network. This global web will not only produce fundamental knowledge about our universe — knowledge that would be otherwise difficult if not impossible to extract — but will also add further impetus to scientific research across the world. It will foster communications among the scientists themselves but also among nations and governments, funding agencies, and research institutions.

When I recently discussed the big discovery with my colleague Kip Thorne at Caltech, he swiftly mentioned that without LIGO carefully and deliberately morphing into a “big science” project, the chances that it would have achieved success would be much smaller. It was in this spirit that Caltech professor Barry Barish, a master not only of scientific judgment, but also of forming international collaborations, became involved at a critical moment in the development of the project. He proceeded (along with other heroes and talented researchers and engineers across many science disciplines internationally) to build LIGO as a highly complex, big science, international project — now demonstratively successful. Gabriela González, the LSC spokeswoman, enthusiastically presented a talk on the vision and success behind LIGO and that of the international gravitational wave observatory network in the Megascience Global Projects session at the 2016 AAAS meeting.

Science and technology are what led to our globally connected world — a world far more powerful than a set of disconnected nations. It will continue being the case that global science collaboration and worldwide projects will change our perspective of the world, impact our way of thinking and living, and produce knowledge-based cooperative societies of unprecedented capacity.

Maria Spiropulu is a professor of physics at the California Institute of Technology and is chair of the APS Forum on International Physics.

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