Astronomical dream becomes reality
His mouth fell open in surprise, when Gideon Koekoek heard the news two months ago that would proudly be presented to the whole world on Monday, 16 October. The detection of two merging neutron stars, first observed with two telescopes, according to the theoretical physicist, solves a whole range of astronomical, chemical and physical problems in one blow. “This is one of the holy grails of astrophysics”, said the researcher, who has been working at Maastricht University since this summer to set up research on gravitational waves and teach students in the Maastricht Science Programme. According to Koekoek, UM will continue to do a lot for research in this area in the coming years.
This observation explains, among other things, how gold is formed in the universe and confirms the theory of scientists that gamma ray bursts occur during the merger of two neutron stars or a black hole and a neutron star.
Koekoek heard the news earlier than the rest of the world because he entered into a collaboration with the Dutch National Institute for Subatomic Physics (Nikhef) on behalf of Maastricht University. In 2011, he earned his PhD with Prof. Jo van den Brand, who led the programme for gravitational waves at this institute for many years. Nikhef conducts research into the elementary building blocks of our universe. Maastricht University has indicated that it wishes to conduct more in-depth research into particle physics and gravitational waves. For this purpose, Gideon Koekoek will build a research group in Maastricht.
Access to data
Thanks to the close collaboration with Nikhef, Koekoek has access to the data that is currently being provided by the three LIGO-Virgo telescopes around the world. Gravitational research in Europe is coordinated by Virgo and in the United States by LIGO. Prof. Van den Brand has been the spokesperson for Virgo for a few months. “Only a handful of scientists have access to this data. The fact that UM students can work with actual data is of course wonderful”, says the enthusiastic researcher/teacher.
Einstein Telescope coming to Limburg?
In three years, by 2020, it will be decided where in Europe the successor to the current telescopes will be built. According to Koekoek, South Limburg is a very serious candidate. “Important players in this field find South Limburg the most suitable because of the soil composition; the device has to be built underground. The UM research group that I will have put into place by then, would then really be in a unique physical position in this scientific field of research.” The so-called Einstein Telescope is expected to detect gravitational waves daily.
About the importance of the current discovery, Koekoek is clear: “Technology is derived from the deciphering and understanding of natural laws. Take, for instance, electricity or thermodynamics—researching and unravelling these natural laws has led to the development of smartphones and cars. And research into gravitational waves will also open doors to new technologies.” This also expands our basic knowledge of nature and the universe. “The universe is basically a giant laboratory. We can never observe and measure colliding black holes on earth. Now we can study and understand these phenomena better.”
What are gravitational waves?
Gravitational waves are ripples in space-time that occur when two major celestial bodies are rotating around each other (e.g. black holes). The gravitational waves move outwards at the speed of light. You can compare this to the ripples in the water when throwing a stone into a pond. A gravitational wave has an effect on the earth. This type of wave causes the earth to stretch a little. In 2015, for the first time, gravitational waves were shown to be responsible for a stretch of 100 billionth of a nanometre, which is 1 millionth of the size of a proton.
Black holes and neutron stars
A black hole arises when the fuel of a heavy star runs out. The star does not have enough outward pressure and then gravity causes it to contract to the point that even light cannot escape its force. A black hole does not give off light, but instead sucks in light. That explains the name: black hole. A neutron star is formed when a star is massive enough to collapse, but does not form a black hole. Instead, a dense ball of neutrons remains. The magnetic field of a neutron star allows charged particles to accelerate, which emits light. Unlike black holes, however, neutron stars are detectable with optical telescopes.