DIY gravitational waves with ‘BlackHoles@Home’ project

On Citizen Science Day researchers are turning to the public for help interpreting gravitational wave data generated by the collision of binary black holes.

Science enthusiasts enthralled by the revelation of the first image of a black hole are being offered the opportunity on Citizen Science Day (13/04/19) to lend computing power to the analysis of gravitational waves generated by the collision of such spacetime objects and massive neutron stars.

The BlackHoles@Home project uses highly efficient simulation grids so that binary black hole collisions can be modelled on desktop computers. The black dots represent the black hole horizons for two black holes of different masses. ( Image courtesy of Z.Etienne/WVU)

The effort, which is being led by West Virginia University assistant professor Zachariah Etienne, invites the public to lend their own computers to help the scientific community unlock the secrets contained in gravitational waves observed when black holes and neutron stars smash together.

Etienne says: “As our gravitational wave detectors become more sensitive, we’re going to need to greatly expand our efforts to understand all of the information encoded in gravitational waves from colliding binary black holes.

“We are turning to the general public to help with these efforts, which involve generating unprecedented numbers of self-consistent simulations of these extremely energetic collisions. This will truly be an inclusive effort, and we especially hope to inspire the next generation of scientists in this growing field of gravitational wave astrophysics.”

By seeking public involvement through the use of vast numbers of personal desktop computers, Etienne and others hope to dramatically increase the throughput of the theoretical gravitational wave predictions needed to extract information from observations of the collisions.

He continues: “Each desktop computer will be able to perform a single simulation of colliding black holes.”

A simulation of colliding black holes using the software that will be available to citizen scientists (Zachariah B. Etienne)

The first detection of gravitational waves from colliding black holes was made by LIGO in 2015 opening a new window on the universe, enabling scientists to observe cosmic events spanning billions of years and to better understand the makeup of the Universe. In addition to this, it formed the basis of the beginning of a new era of astronomy — multi-messenger astronomy.

For many scientists, the discovery also fueled intensified efforts to more thoroughly test the theories that explain how the universe works — with a particular focus on inferring as much information as possible about the black holes prior to their collision.

First predicted by Albert Einstein in 1916, gravitational waves are ripples or disturbances in space-time that encode important information about changing gravitational fields.

Since the 2015 discovery, LIGO and Virgo have detected gravitational waves from eight additional black hole collisions. This month, LIGO and Virgo began new observing runs at unprecedented sensitivities.

Black holes are known to contain two physical quantities: angular momentum and mass. This angular momentum can be broken down further into direction and speed. This means that Etienne's team are examining a total of eight parameters when LIGO or Virgo detect waves from a collision of two black holes.

Etienne explains: “The simulations we need to perform, with the public’s help, are designed to fill large gaps in our knowledge about gravitational waves from these collisions by covering as many possibilities as we can for these eight parameters. Current black hole simulation catalogues are far too small to properly cover this wide space of possibilities.

“This work aims to provide a critical service to the scientific community: an unprecedented large catalogue of self-consistent theoretical predictions for what gravitational waves may be observed from black hole collisions. These predictions assume that Einstein’s theory of gravity, general relativity, is correct, and therefore will provide deeper insights into this beautiful and complex theory. Just to give you an idea of its importance — if the effects of Einstein’s relativity theory weren’t accounted for, GPS systems would be off by kilometres per day, just to name one example.”

Etienne and his team are building a website with downloadable software based on the same Berkeley Open Infrastructure for Network Computing, or BOINC. This system is also used for the SETI@Home project and other scientific applications. The free middleware system is designed to help harness the processing power of thousands of personal computers across the globe.

The West Virginia team has named their project BlackHoles@Home and expects to have it up and running later this year.

The team have established a website where the public can begin learning more about the effort: https://math.wvu.edu/~zetienne/SENR/.

To get in involved in Citizen Science projects operated by NASA, visit: https://science.nasa.gov/citizenscientists?fbclid=IwAR1etkT-gWdh_YwGlCIFcVuaL215gjOd1FZntIZn6fGbglKHixey9BptiAE