In 1915, Einstein published the theory of general relativity,  the most elegant and complete description of gravity, space and time ever constructed. This theory has been verified in a variety of settings both on earth and in space. One of Einstein's most fundamental predictions is the existence of invisible ripples in space-time called gravitational waves. While there is good evidence for their existence, they still have not been directly detected. Nearly 100 years after Einstein's work, Dr. Maura McLaughlin, of West Virginia University, and colleagues are on the brink of detection of these waves through monitoring of  exotic stars called pulsars with the largest radio telescopes in the world. Pulsars emit extremely regular pulses and accurate timing of these celestial clocks allows scientists to detect tiny perturbations. These perturbations allow scientists to search for binary companions or planets, measure stellar masses, and test general relativity.

Dr. McLaughlin's use of radio pulsars is much more cost-effective than costly ground-based gravitational wave detectors like LIGO, and leads to many discoveries that come "for free" along with the gravitational wave search. In addition, radio pulsar timing has impressive ramifications for radio communications, accurate timekeeping on Earth, and could be used for interstellar navigation. Finally, she is committed to involving students at all levels in her work through a program called the Pulsar Search Collaboratory that has involved over 2000 high-school students from 19 states in pulsar searching using the Green Bank Telescope in West Virginia. These students are making real contributions to the sensitivity of the experiment to gravitational waves, as it increases with the number of pulsars in the array.

Current projects include:

• Detecting Gravitational Waves: Dr. McLaughlin and her colleagues in the NANOGrav collaboration times a number of pulsars in a "pulsar timing array" to search for correlated changes due to gravitational waves. The main sources Dr. McLaughlin expects to detect are supermassive black hole binary systems. This will allow her to directly measure properties of black holes for the first time and will also inform our understanding of galaxy evolution and cosmology. Dr. McLaughlin may also be able to constrain exotic phenomena such as cosmic strings or early universe inflation through this experiment!

• Exotic Pulsar Physics: The pulsar searches constantly reveal individually interesting pulsars, leading to breakthroughs in many branches of physics. Dr. McLaughlin and her team are therefore weighing stars more accurately than possible through any other method. This is leading to new models for the composition and structure of these exotic stars, denser than anything we can create in laboratories on earth. They are also performing many different tests of  general relativity on exotic binary pulsar systems.

• Pulsar Search Collaboratory: Over 2000 students have been involved in pulsar research through the Pulsar Search Collaboratory program. Students in this program search for pulsars to add to the pulsar timing array. Most of the students who've participated in this program have stayed in STEM fields. In addition, half of the students are female and many are from rural households. Therefore, the program is playing a large role in diversifying the STEM pipeline. Dr. McLaughlin and colleagues hope to expand this program by establishing PSC "hubs" throughout the country in order to involve more students in this research. Dr. McLaughlin is currently co-producing a documentary called "Little Green Men" about the program. 

• The Arecibo Observatory and the Green Bank Telescope: Dr. McLaughlin and her team perform their observations with the Arecibo Observatory (in Puerto Rico) and the Green Bank Telescope (in West Virginia). These are the largest and second largest telescopes in the world, and the most sensitive telescopes for this experiment. Unfortunately, both of these telescopes are under threat of closure by the National Science Foundation. Dr. McLaughlin hopes to raise funds for the telescopes both to support her own research, to give students and young scientists the opportunity to work with these unique instruments, and to support the communities of dedicated workers at these facilities.