The first direct observation of gravitational waves Sept. 14, 2015, was a Nobel Prize-worthy discovery that not only confirmed Albert Einstein’s theories on general relativity, but ushered in a new epoch in our ability to study and understand the universe.
This multipart series will explore the importance of federal investment in a curiosity driven pursuit 50 years in the making, and ask local leaders and those close to the project how something infinitesimally small could send such enormous shockwaves through the scientific community.
By Jonathan Samples | Bugle Staff
In February, the U.S. House of Representatives Science, Space and Technology committee held a special hearing to discuss the recent detection of gravitational waves by scientists working with the Laser Interferometer Gravitational-Wave Observatory.
Among the representatives in attendance during that meeting was Congressman Bill Foster. The Illinois Democrat holds rank among his colleagues as the only Ph.D. scientist in Congress. As a former high-energy physicist and particle accelerator designer, Foster took the opportunity to make his excitement over the historic discovery known to everyone who attended the Feb. 24 hearing.
“This is a discovery that will live on in the science textbooks forever,” he told the committee. “And with this discovery, we have opened a new window into the universe, we have verified that our new telescope is working and now the fun begins.”
Foster is no stranger to milestone discoveries. While working on his Ph.D. thesis, Foster became a member of a team that detected a neutrino burst from supernova SN 1987A. That discovery earned the team the 1989 Bruno Rossi Prize for cosmic ray physics. While working at Fermi National Accelerator Laboratory, he was a member of the team that discovered the top quark – the heaviest known form of matter.
And while the current political climate often places balanced budgets over long-term science and research goals, Foster said the LIGO project is an example of federal investment in scientific research paying remarkable dividends.
“Twenty-five years after the National Science Foundation began courageous and sustained funding for [LIGO] to begin constructing this large and technically risky project, physicists have spectacularly confirmed Einstein’s theory,” he added.
The historic discovery that came from that investment has received praise from both sides of the aisle and it is one that Foster believes worthy of the Nobel Prize.
When the Bugle sat down with him to discuss the recent discovery and the future of LIGO, the 11th District congressman shared his thoughts on the intersection of science and politics and stated just how important he feels curiosity driven research is to the future of our country and our world.
“Deciding what fragment of your GDP you reserve for curiosity driven research or art or the other things that you do for your country so that you can be proud of it is essentially a political decision,” Foster said. “But, there’s also an indirect, but important, benefit to getting the next generation of students excited about science.”
On the shoulders of giants
To be clear, gravitational waves weren’t actually “discovered” by LIGO researchers, who on Sept. 14, 2015, detected infinitesimal fluctuations in the fabric of space-time.
The tiny vibrations detected by twin LIGO interferometers in Livingston, Louisiana, and Hanford, Washington, were caused by the collision of two massive black holes 1.3 billion years ago. That collision produced an enormous amount of energy in the form of gravitational waves, which traveled away from their source near the speed of light on a billion-year journey toward earth.
LIGO is a system of two identical detectors located almost 2,000 miles apart. Each detector consists of two 4-kilometer-long vacuum tubes, arranged in an L-shape, through which scientists send laser beams capable of detecting the gravitational waves.
By a stroke of luck, the gravitational waves produced by the collision of these two black holes passed through earth just as LIGO scientists turned on their equipment.
“They were actually not quite started with the official data taking run,” Foster said. “They were just tuning [the equipment] up, when all of a sudden this signal arrived.”
For the first time, scientists had made direct observation of gravitational waves, thus confirming some of the fundamental features of Albert Einstein’s field equations on general relativity.
Gravitational waves had been theorized by Einstein in 1916, and scientists have been working ever since to detect the tiny ripples created during large cosmic collisions. In 1974, the discovery of a pair of neutron stars 21,000 light years away offered the first evidence of gravitational waves.
However, the story of LIGO goes back even further.
“If Einstein was still alive, I would have loved to have shown him the data; I would have loved to have seen what his expression would have been,” said Rainer Weiss, a professor emeritus of physics at MIT and the brains behind LIGO.
Beginning with a thought experiment he proposed to students in a course he was teaching on general relativity in the 1967, Weiss soon demonstrated that a laser interferometer could, in theory, detect gravitational waves. Eventually, he completed the invention of an interferometric gravitational wave detector – a 1.5-meter prototype of what later became LIGO.
“Rai Weiss is an old friend of mine and quite likely to end up winning the Nobel Prize for this,” Foster said.
The story of how this prototype eventually led to one of the most important discoveries of the 21st century unfolded over the next four decades.
Scientists had been hunting for gravitational waves ever since Einstein first hypothesized their existence. But, Foster said it was Weiss who realized that it was conceivable to use available technologies to construct an instrument with the necessary sensitivity to detect the tiny waves. “Then, he spent the next 20 years getting someone to fund bigger and bigger prototypes,” Foster added.
A remarkable scientific achievement in its own right, the detection of gravitational waves would not have been possible without funding from the National Science Foundation.
“That is the big reason why we made this big whoop de doo about this discovery,” Weiss said. “NSF was fundamental to this whole thing.”
Part two of this series will explore how LIGO benefited from federal funding, as well as the different ways its historic discovery could shape the next generation of scientists.