More than a thousand people gathered at Jadwin Hall on Thursday, April 12 and filled five auditoriums to attend the 43rd Donald R. Hamilton Conference given by Kip Thorne, Professor Emeritus of the California Institute of Technology.
Thorne, who won the Nobel Prize in Physics 2017 along with Barry Barish of Caltech and Rainer Weiss of MIT, spoke of his transcendental discovery of gravitational waves, detected by the laser interferometry gravitational wave observatory of a hole fusion black 1.3 billion light years ago.
Thorne opened by narrating the events that led to this historic discovery in 2015.
"When multicellular life was forming on Earth 1,300 million years ago, but in a galaxy far, far away, two black holes they crashed, creating a giant burst of gravitational waves, which traveled … to the great confines of intergalactic space, "he said.
These gravitational waves reached the outer edges of the Milky Way 50,000 years ago, during the Neanderthal era.
"On September 14, 2015, they arrived on Earth, touching first on the Antarctic Peninsula, they traveled across Earth, intact through all the matter on Earth, and emerged in Livingston, La., In one of the two LIGO detectors, "Thorne continued.
The gravitational waves as detected in 2015 are really incredibly difficult to collect, mainly due to its minute effect in space-time. When cosmic monstrosities occur, such as black hole collisions and neutron star collisions, gravitational interactions with the environment around them are so violent that they deflect spacetime.
These waves in space-time travel enormous distances to be detected by LIGO, so much so that the waves in space that we observe are tiny compared to the waves that surround the collision.
LIGO uses an intricate system called an interferometer, or a laser beam splitter reflected by 40-kilogram mirrors to find these small undulations in reality.
Thorne elaborated on the size of those undulations.
"Start with the thickness of a human hair, divide by 100 and you get the wavelength of the light used to measure [gravitational waves]divide by 10,000 and you get the diameter of an atom," Thorne said. "Divide by 100,000 and you get the diameter of a nucleus of the atom, divide by another factor of 1,000 and you get the factor of the movement of the mirror."
That same day, Thorne and Weiss paid homage to the late Robert Dicke, a former teacher of physics whose work on gravity was an integral precursor to Thorne & s and Weiss's work on gravitational waves. Both attended the dedication of a plaque outside the Frist Campus Center, called the Palmer Physical Laboratory during Dicke's tenure, where in the 1960s and 1970s Dicke and his colleague physics professor John Archibald Wheeler proposed the existence of gravitational singularities, coining the term "black holes". "
Dicke passed away in 1997.
" Thorne's passion was contagious and, despite his rather high scientific stature in the present, he still presented himself as very accessible, "said Andrew Wu & # 39; , a concentrator of astrophysics.
Wu asked Thorne a question about the way gravitational waves affect time.
"Despite having had some exposure to the concepts of relativity before, his answer still surprised: gravitational waves seem to change the flow of time only by affecting it. space, and therefore, how light travels through it, which is the way we observe its effect in time, "Wu said.
" Specifically he said he found the first years of undergraduate very challenging, "he said. Elliot Davies & # 39; 20, also an astrophysics concentrator. "Knowing him gave me the hope of being able to follow in his footsteps; It inspired me to work hard even when I'm fighting in Princeton. "
The possibilities of further study of gravitational waves, according to Thorne, are endless.
" In the middle of this century, I think the greatest effort is to explore the first second of the universe with gravitational waves, "Thorne said.
Thorne explained that when the universe was a billionth of a second old, the forces described Maxwell's equations that began to apply to the universe. occurred within bubbles that produced bursts of gravitational waves.
These waves must be detected by the spatial antenna of the laser interferometer, a system of three satellites in space designed to detect gravitational waves from the primordial universe.
two years that LIGO discovered gravitational waves with colliding black holes, "said Thorne." I invite you to speculate about the next 400 years with combined electromagnetic and gravitational waves. "