LIGO's Impact on Science
Gravitational wave detectors like LIGO will answer some outstanding questions related to gravitation and astrophysics, such as:
- Is general relativity the correct theory of gravity?
- How does matter behave under extreme densities and pressures?
- How abundant are stellar-mass black holes?
- What is the central engine driving gamma ray bursts?
- What happens when a massive star collapses?
LIGO will also directly engage the scientific community in “multi-messenger astronomy”, a collaborative effort where gravitational wave detectors and various kinds of telescopes (observing with electromagnetic radiation such as visible light, x-rays, gamma rays, radio waves, etc.), and even neutrino detectors, will observe astronomical sources at the same time. Each method of observing provides a different look at the same objects or phenomena allowing them to be studied in multiple ways and revealing relationships and interactions never before observed.
Last but not least, through its advances in technology and scientific methods, LIGO also contributes to other fields of science and to the broader technology enterprise.
LIGO and Astronomy
The direct detection of gravitational waves requires multiple detections from widely separated sites. To enhance detection capabilities, LIGO researchers are working closely with gravitational wave researchers at Virgo in Italy and GEO600 in Germany, they are assisting the Japanese as they build KAGRA. In addition, for years, LIGO staff have been training Indian engineers to prepare for the construction of the third LIGO interfereometer in India.
Detecting gravitational waves isn't the only contribution to science LIGO wants to make, however. The next natural step in the evolving field of gravitational wave astronomy is to delve into the nature, dynamics, and structure of gravitational wave sources. Exploring this realm requires that electromagnetic (EM) astronomers get a chance to observe and analyze any light coming from source objects (gravitational waves have nothing to do with the electromagnetic spectrum, so the sources of gravitational waves are usually invisible to telescopes, except in a few exceptional cases). To that end, from the beginning, LIGO partnered with Earth-based and orbiting observatories around the globe that agreed to search the skies for a glimmer of light resulting from a gravitational wave source event. Less than two years after LIGO's first detection of gravitational waves, this momentous 'next step' was taken. In August of 2017, LIGO detected a gravitational wave from what immediately seemed to many to be an unusual source. Combining their data, LIGO and Virgo quickly localized the region of sky from which this signal emerged. This information was shared with LIGO's EM partners (over 90-strong by the summer of 2017) and within hours, a clearly visible aftermath of what is now believed to be a collision of two neutron stars was physically seen in a telescope! For the first time, LIGO's and Virgo's gravitational wave vision enabled EM astronomers to directly observe a gravitational wave generator within HOURS of its generation! Optical, x-ray, radio, infrared and gamma ray telescopes, as well as neutrino detectors all participated in the post-GW170817 observations, to date now believed to be the most studied single astronomical event in human history.
The rewards to the EM astronomical community in following-up LIGO detections are only beginning to be realized, and the potential for discovery is undeniable. This growing field of ‘multi-messenger’ astronomy represents one of the largest collaborations that LIGO and other detectors will help to facilitate amongst the global scientific community. LIGO is at the heart of this new scientific endeavor, which promises to be extremely fruitful for all involved.
LIGO's Impact on the Broader Scientific and Technical Community
LIGO’s impact (and the impact of its sister facilities) reaches far beyond physics, astrophysics, and astronomy. The effort to design and build detectors like LIGO and to understand the characteristics of the expected gravitational wave signals have resulted in multiple scientific and technological applications and advancements in many fields such as those listed in the table below.
Scientists and engineers in these fields are already benefitting and will continue to benefit from advances gravitational wave detector technology and data analysis methods developed by LIGO.
For a deeper discussion on the ways in which gravitational wave science impacts the broader scientific community, you may want to read the Gravitational Waves International Committee (GWIC) document, “The future of gravitational wave astronomy: A global plan”.
Transfer of LIGO Technology Developments to the Broader Technology Enterprise
During its development, LIGO has already spawned innovative technology and invention. Innovations in areas as diverse as lasers, optics, metrology, vacuum technology, chemical bonding, and software algorithm development have resulted directly from LIGO’s pioneering work. Some of these ‘spin-off’ technologies are listed in the table below.