"We are at a special moment in our journey to understand
the universe and the physical laws that govern it. More than ever
before astronomical discoveries are driving the frontiers of elementary
particle physics, and more than ever before our knowledge of the elementary
particles is driving progress in understanding the universe and its
contents." - Report by the NRC Committee on the Physics of the
A recent NRC report identifies the most important, timely and promising
scientific questions at the intersection of physics and astronomy, and
suggests an action plan for seeking the answers. "The advances
made by physicists in understanding the deepest inner workings of matter,
space and time and by astronomers in understanding the universe as a
whole as well as the objects within it have brought these scientists
together in new ways," the report says. "The questions now
being asked about the universe at its two extremes - the very large
and the very small - are inextricably intertwined, both in the asking
and in the answering, and astronomers and physicists have been brought
together to address questions that capture everyone's imagination."
The report, "From
Quarks to the Cosmos: Eleven Science Questions for the New Century,"
is the work of the ad hoc Committee on the Physics of the Universe,
chaired by Michael Turner of the University of Chicago. Phase I of the
committee's report was released in January 2001; the prepublication
copy of the final report became available in April 2002. It is intended
to complement two prior NRC reports that highlighted scientific priorities
in these fields: "Astronomy and Astrophysics in the New Millennium"
and "Physics in a New Era: An Overview" (see FYIs #62,
2000 and #90,
Below are the questions identified by the Committee as "the key
research issues facing the research community" at the interface
between astronomy and physics. The first five chapters of the report
provide background on current scientific understanding of these issues
and how the Committee arrived at these questions. FYI
#68 will contain the Committee's recommendations for a research
strategy to explore these questions.
The eleven questions are:
What is the dark matter?
What is the nature of the dark energy?
How did the universe begin?
Did Einstein have the last word on gravity?
What are the masses of the neutrinos, and how have they
shaped the evolution of the universe?
How do cosmic accelerators work and what are they accelerating?
Are protons unstable?
Are there new states of matter at exceedingly high density
Are there additional spacetime dimensions?
How were the elements from iron to uranium made?
Is a new theory of matter and light needed at the highest
According to the report, "Each
question reveals the interdependence between discovering the physical
laws that govern the universe and understanding its birth and evolution
and the objects within it. The whole of each question is greater than
the sum of the astronomy part and the physics part of which it is comprised....
Taken as a whole, the questions address an emerging model of the universe
that connects physics at the most microscopic scales to the properties
of the universe and its contents on the largest physical scales."
The Committee's suggestions for pursuing these research goals
will be highlighted in the next FYI.
The prepublication version of the approximately 164-page report can
be read online at http://www.nationalacademies.org/bpa/projects/cpu/report.
The hardcopy version is not yet available from the National Academy
Audrey T. Leath
Media and Government Relations Division
American Institute of Physics