Cosmic Credit
David Appell errs in attributing the discovery of dark energy so completely to Saul Perlmutter’s Supernova Cosmology Project (SCP) team in “Dark Forces at Work” [Insights]. The SCP made real contributions to the discovery of dark energy, but other groups had solved some of these problems earlier.
In 1988 a Danish team searched for distant supernovae using methods anticipating those of the SCP. And the program of supernova discovery for nearby objects at Cerro Tololo Inter-American Observatory in Chile formed the basis for using supernovae as distance indicators, not the robotic search Perlmutter worked on. The SCP did publish a result in July 1997 that claimed supernova observations were unlikely to be consistent with dark energy, but our High‑Z Supernova Search Team developed superior methods for dealing with dust, published in 1996. With careful observation of supernovae, we were confident that we saw cosmic acceleration, which we announced in February 1998. A paper detailing our work was submitted to the Astronomical Journal in March 1998 and appeared in print before the SCP paper was submitted.
Everybody has a lot to be proud of, but credit should be given where it is due.
--Robert P. Kirshner
Harvard University
APPELL REPlIES: Kirshner is not entirely correct and, as a member of the High-Z team, perhaps not entirely objective. The Danish team did perform consequential early measurements, but only on one supernova and too late to obtain its peak brightness. Both the SCP and High-Z teams did important work and exchanged vital data and insights in both directions. But it is undisputed that the SCP announced its discovery first, on January 9, 1998, at a meeting of the American Astronomical Society. In Kirshner’s book The Extravagant Universe (Princeton University Press, 2002), he describes the two teams’ relationship as “getting it first” versus “getting it right.”
I am sure that history will acknowledge the contributions of both teams in the final analysis.
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Add CommentGreen nuclear power is the only long-term solution to (1) ameliorate global warming, (2) dependence on foreign oil/gas, and (3) oil/gas depletion. Only two prime energy sources, coal and uranium, can affordably deliver terawatts of "mother" electricity for: (A) heavy industry, i.e. manufacture of autos, ships, airplanes, etc; (B) power for vast fleets of future electric plug-in autos; and (C) production of portable synfuels (hydrogen and ammonia) and biofuels to replace oil. However coal worsens global warming and must be preserved as raw material to make organics when oil is gone. This leaves uranium as the only "big-mama" green energy source, an "inconvenient truth". Green solar and wind energy are useful for small-quantity power generation in select locations. But at terawatt levels, immense areas of land and/or sea would be needed, necessitating enormous maintenance operations, spoiling scenic land- or sea-scapes, and destroying local ecosystems. As scientifically documented in "The Nuclear Imperative" (ISBN 1-4020-4930-7), uranium and thorium can affordably sustain global energy needs for some 2000 years, using proven fuel reprocessing and advanced reactor technology. For the USA, 500 additional nuclear reactors are required, built on 9000 acres (@ $1.5 trillion), compared to 1,500,000 windmills with storage batteries on 6,000,000 windy acres (@ $4.5 trillion). Ten times these numbers are needed world-wide. (Costs in 2005 dollars). Contrary to false propaganda by anti-nuclear groups, the cost of multi-giga-watts of electricity is three times less expensive with nuclear than for wind or solar. Solar and wind power generation requires expensive energy storage systems (batteries, etc) when there is no sunshine or wind. Also many miles of access roads for maintenance are needed to keep blades or solar panels clean from bird droppings, dead birds, sand erosion, and storm damage, and to periodically replace electrodes on storage batteries. Should the USA limit itself to solar and wind energy, it is guaranteed to become impoverished and dependent on synfuels imported from other countries (future OPECs), who have nuclear power when oil fields are depleted. GNEP is essential and moving in the right direction. Advanced fast reactors like the IFR developed at Argonne will be gradually phased in during the next few decades. Von Hippel exaggerates saying they are too expensive. A number of experimental fast reactors are already running successfully. Once fielded, costs are estimated to be about 10% higher than current thermal reactors.
Reply | Report Abuse | Link to thisSheffrey, congratulations on making so many groundless and baseless assertions, omissions, and plain lies in such a short text.
Reply | Report Abuse | Link to thisIt's a record.
PS give my regards to Alice while you're still in wonderland.
Cyrl, can you refute his assertions? What are his omissions? Where are his lies?
Reply | Report Abuse | Link to thisAccording to the International Atomic Energy Agency, there remains only 70 years of uranium ore on the planet at current rates of consumption. So nuclear energy is no solution to the forthcoming energy depletion crisis. Most experts agree that the only solution is energy efficiency coupled with renewables, unless nuclear fusion proves to be viable. The Environment is calling for an urgent war on waste.
Reply | Report Abuse | Link to thisEco-steve that's 70 years of uranium reserves at current prices. There's hundreds of millions of tons of the stuff accessible for a bit more effort in the continental USA alone.
Reply | Report Abuse | Link to thisBut the whole economics of calling perfectly useable fuel "waste" should be a source of shame to all involved.
Who is the expert on nuclear energy and what is the true cost of it? And if it is trully an enviromentally friendly energy, why is it polluting the area around Hanford in Washington State?
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