Letters

Economic Theories not Scientific

I congratulate H. Eugene Stanley for his very illuminating Back Page (APS News, December 2008) on the role of physics in the current financial crisis. I wholeheartedly agree with him regarding the contention that physicists are responsible for it. That is simply a red herring, introduced to shield those who are truly responsible.

On the other hand, I disagree with his characterization of economics as a science. Current economic theories are essentially political, and insofar as I can discern are divorced from a number of well established scientific facts: that resources are finite, for instance. While we see criticisms of capitalism as being incapable of recognizing the worth of things that cannot be valued in units of currency, such as clean air and water, biodiversity, and human dignity among others, the same can also be said of other recent economic theories such as Marxism and Maoism.

Because economic theories are essentially political, they tend to be ideological, putting them in the same category as religion. Which as we all know is the antithesis of science.

Stanley’s intuition that an overconnected system is disadvantageous is correct in my opinion. Since the introduction of requirements for quarterly reporting, listed corporations have largely abandoned long-term planning, focusing instead on short-term results to please the analyst-priests. In addition, programmed trading enhances the connectivity, providing a substantial positive feedback response. A simple fix would be to introduce significant but random delays in large programmed trades, in an effort to partially decouple them.

Stephen Schiff
Aldie, VA

Malthus Still Relevant

The Back Page on Econophysics by H.E. Stanley does not mention an equally or even greater failure. Malthus warned of the problem, but prematurely. Today only a few lonely voices are heard, when it should be clear that “solving” the energy problem without simultaneously addressing the population growth is counterproductive. The most important contribution Physics can make is promoting the importance of considering all the interacting parts, rather than developing a technical fix for one part while ignoring its effect on the whole.

Elmer Eisner
Houston TX

Correction Offered to Science and History of Cosmic Acceleration

As a member of the High-Z Supernova Search Team (HZT), I think it is worthwhile to correct both the science and the history that were described in “This Month in Physics History” that appeared in the January APS News.

On the science, Type Ia supernovae are not standard candles:  their luminosities vary by a factor of 3. Sorting the bright from the dim by the shape of their light curves to get precise distances was introduced by HZT member Mark Phillips in 1993.  

Similarly, absorption by interstellar dust can mimic dimming that is due to accelerated expansion. Riess, Press, and Kirshner developed a solution to this problem, published in 1996, which was essential to the analysis of distant supernovae submitted by Riess and HZT to the Astronomical Journal on March 13, 1998. This paper was accepted on May 6, and published in September 1998. The Supernova Cosmology Project also developed an effective way to measure dust absorption to individual supernovae, but not until 2003. Their article on cosmic acceleration was submitted to the Astrophysical Journal on September 8, 1998 and appeared in the June 1999 issue.

On the history, the January 1998 AAS meeting was not the time and place where the world learned we live in an accelerating universe. At the AAS press briefing, 5 speakers, including Peter Garnavich from HZT, concurred that we live in a low density universe that would expand forever. In that public setting, no one claimed that the universe was accelerating [see, e.g. John Noble Wilford, The New York Times, Jan 9, 1998 “New Data Suggest Universe Will Expand Forever”.] The first clear public statement that evidence from supernovae indicated cosmic acceleration took place in February 1998, at the Dark Matter meeting in Marina Del Rey. Alex Filippenko of HZT said “the dimness of the supernovae–pointing to unexpectedly large distances–implies that cosmic expansion has actually sped up in the years since the stars exploded.” This triggered a flood of public attention, including an interview of HZT member Adam Riess on The News Hour.  Cosmic acceleration seemed like news to the world in February. Not January.

In March 1998, Saul Perlmutter was asked by The New York Times to explain his reluctance to assert cosmic acceleration at the AAS in January. According to the Times, “Describing their results in January, Dr. Perlmutter acknowledged that the evidence strongly suggested a cosmological constant, but went no further. ‘We were trying to be very conservative until we had more observations’.” Nobody claimed to have announced cosmic acceleration in January 1998. I think we should mark the dates of scientific discoveries from the submission of refereed publications, not commemorate the extrapolations of reporters who get ahead of prudent scientists in drawing reliable conclusions. I say we should have the anniversary on March 13! On this basis, I look forward eagerly to the next “This Month in Physics History.”

References to the articles mentioned above can be conveniently found at http://www.cfa.harvard.edu/~rkirshner/whowhatwhen/Thoughts.htm

Robert P. Kirshner
Cambridge, MA

Meeting Planners Need to Think Green

In this era of green thinking and friendliness to Planet Earth, I make a plea to all those who organize (APS and other) conferences. Surely, it makes sense, when deciding on a venue, to avoid far-flung corners of the US. Holding a major scientific meeting inevitably means that some participants will need to fly, but choosing Hawaii, for example, as a destination means that every participant will clock up thousands of air miles and be responsible for significant CO₂ emissions. Why not choose a major airline hub, or somewhere that is close to the workplace of many of the attendees? This will minimize the carbon footprint of the meeting, reduce costs associated with travel, and lessen the tedium of hours and hours spent confined in a metal tube.

Paula Rosen
Reading, Berkshire, UK