November 2019, ScientificAmerican.com 69MORE TO EXPLORE
The Detection of Gravitational Waves with LIGO. Barry C. Barish. Paper presented at the American Physical Society Division of
Particles and Fields Conference, Los Angeles, Calif., January 5–9, 1999. Preprint available at https://arxiv.org/abs/gr-qc/9905026
Observation of Gravitational Waves from a Binary Black Hole Merger. The LIGO Scientific Collaboration and the Virgo Collaboration
in Physical Review Letters, Vol. 116, No. 6, Article No. 061102; February 12, 2016.
KAGRA: 2.5 Generation Interferometric Gravitational Wave Detector. The KAGRA Collaboration in Nature Astronomy, Vol. 3,
pages 35–40; January 2019.
FROM OUR ARCHIVES
The Future of Gravitational Wave Astronomy. Lee Billings; ScientificAmerican.com, February 12, 2016.
scientificamerican.com/magazine/saMIRROR, MIRROR
Another view of the delicate apparatus that
keeps a mirror in place, before installation in
KAGRA’s cryogenic system. The sapphire
mirror is held in the cylindrical chamber in
the bottommost stage, suspended by four
thin sapphire fibers. The remaining three
vertical stages contain components to iso-
late the mirror assembly from seismic noise
and are fabricated with a variety of materi-
als that can withstand KAGRA’s extremely
cold operating conditions.COMMAND CENTER
All of KAGRA’s instruments are controlled
from this room at the surface, a 10-minute
drive from the underground cavern’s
entrance. A wall-mounted bank of six large
screens displays the temperature, humidity
and operational conditions of the KAGRA
site, and smaller screens along the room’s
right wall show snapshots of laser light cas-
cading through the vacuum tunnels, as well
as information about seismic activity
throughout Japan.OPPOSITE PAGE: INSTITUTE FOR COSMIC RAY RESEARCH, UNIVERSITY OF TOKYO; THIS PAGE: ENRICO SACCHETTI
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