K-SEC
Meeting Summary – November16, 2015
A. Attendees (in ABC order):
Ishikuro, Kanzawa, Kotake, Nishimura, Nishiwaki, Okai, Sadayasu, Sekiguchi, Tomozawa,
Tsurumoto, Umemura (Total of 11)
B. Materials read:
1. Gravitational waves – presented and summarized by Kanzawa
In 1916 Albert Einstein proposed his theory of General Relativity which revolutionized our
understanding of space and time. According to this theory, space and time are stretchable
and can be deformed as an elastic medium by mass and energy. Among the surprising
consequences of General Relativity is the existence of gravitational waves, deformations of
space and time generated by accelerating masses and propagating at the speed of light.
Many astrophysical phenomena can produce gravitational waves. The explosion of a star at
the end of its life; the merger of two stars falling onto each other; the oscillation of a newly
born black hole and even the primordial explosion that gave birth to the Universe are
examples of phenomena that can produce gravitational waves. Their detection will open a
new window to the Universe and allow the observation of phenomena which have been
undetectable so far.
For all these reasons physicists and astronomers are developing a new class of
gravitational wave detectors. These new detectors use ultra-stable lasers to monitor the
distance between test masses placed several km apart with unprecedented precision.
Variations in the distance between the test masses that are ten billions times smaller than
the size of an atom will be measurable, thus allowing the detection of gravitational waves
such as those emitted by black holes as far as several billion light-years.
In Japan we are building KAGRA, a gravitational wave detector that will be located at
Kamioka in Gifu Prefecture. KAGRA has unique features such as being the first km-scale
detector located underground and using test masses cooled down to cryogenic
temperatures. The use of these solutions will reduce the disturbances due to natural
seismic noise and residual thermal vibrations and will make KAGRA the most advanced
detector in the world.
2. China Burns Much More Coal Than Reported, Complicating Climate Talks – presented and
summarized by Tomozawa
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This is a New York Times article dated November 3, 2015, written by Chris Buckley.
China, the world’s leading emitter of greenhouse gases from coal, has been burning up to 17
percent more coal a year than the government previously disclosed, according to newly
released data. The finding could complicate the already difficult efforts to limit global warming.
(The graph in the article shows the revised annual coal usage of 2012 was 4.1 Billion of tons
whereas the previous data was 3.5 B tons.
The sharp upward revision in official figures means that China has released much more
carbon dioxide — almost a billion more tons a year according to initial calculations — than
previously estimated.
Officials from around the world will have to come to grips with the new figures when they
gather in Paris this month to negotiate an international framework for curtailing greenhousegas pollution. The data also pose a challenge for scientists who are trying to reduce China’s
smog, which often bathes whole regions in acrid, unhealthy haze.
The Chinese government has promised to halt the growth of its emissions of carbon dioxide,
the main greenhouse pollutant from coal and other fossil fuels, by 2030. The new data
suggest that the task of meeting that deadline by reducing China’s dependence on coal will
be more daunting and urgent than expected, said Yang Fuqiang, a former energy official in
China who now advises the Natural Resources Defense Council.
Why they produced this revised data at this time? Our group’s consensus was that, by
revising the data upwards, China would have higher starting level to begin with. Now they
may insist to adopt the percentage objective based on the “revised” data rather than the “real”
target value which was agreed in Kyoto protocol.
Tomozawa reported that, the objective of COP21 which is being held in Paris in November
2015 is not to get an agreed upon target for every country but to give each nation freedom to
choose her own target. Each nation would have an obligation to report to UN for the results,
though. This revelation caused one member to comment that “Then we do not need COP21,”
but we agreed that we need some activity going to keep awareness high “politically.”
C. Role assignment for December 7, 2015
Kotake
Sekiguchi
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