Professor of Physics and Astronomy

Dear President Bush:

We are becoming increasingly aware of the connectedness and smallness of our world. Our problems are global- we are all affected by what one area or country does. Mid-western industrial pollution impacts on Washington D.C. air quality; Antarctic ice melting causes flooding in Bangladesh and Peruvian El Ninos can be traced to atmospheric pressure seesaws between the Pacific and the Indian Oceans. The AIDs epidemic's ravages know no boundaries. These realizations have changed the way we think and must change the way we act. Finding ways to deal with these issues and ones like them is a pressing scientific need as well as a political, economic and moral one.

Parallel to these concerns, however, are topics that are pressing even though they do not directly alter the quality of our everyday life. Science deals with day-to-day matters, but it also challenges us to leave the legacy of its discoveries to future generations. The Greeks are remembered because of their findings in philosophy and geometry, not because of territorial conquests. Copernicus' realization of the Sun's centrality marks the Renaissance. We want to be remembered in the centuries that come because of our own great achievements, ones that our descendants will say changed the way they see the world.

New insights in developmental biology—our similarities to not only chimpanzees and baboons, but to fruit flies and worms, the genomic revolution and the invigorated emergence of neuroscience are all candidates for unforgettable discoveries. They must be pursued with all the means at our disposal. I would like to address a totally different one: the birth of our universe.

A century ago there was no scientific theory of the universe's origin. It has been less than 40 years since we obtained the first evidence of radiation in the creation's aftermath and only a decade since we established convincingly that the universe was once a super-dense, ultra hot medium at essentially one common temperature. I said "essentially" because there are small deviations in that record; differences far less that a part per thousand from point to point in the sky, but these provide the clue to all the formations of galaxies, stars and planets that followed. This journey back in time is the greatest archaeological expedition ever undertaken, the uncovering of how our universe began and evolved. We almost have the tools in hand for embarkation on this voyage and should not dawdle.

Through the past century's insights, we have come to realize that we live on an ordinary planet circling a typical star of a mid-sized galaxy. Perhaps there is one additional step—that our very universe is not an anomaly in a continuum of space and time. We can leave a trace greater than Copernicus did. Such discoveries, achieved by scientists engaged in international collaborations and speaking the common language of science may serve as a role model for a world in which national, ethnic and religious barriers are broken down.

I believe it is a pressing issue for the nation and the world to have dreams worthy of the best it can achieve.

Sincerely yours,

Gino Segre

Professor of Physics and Astronomy
University of Pennsylvania
Author of A Matter of Degrees: What Temperature Reveals About The Past And Future Of Our Species, Planet And Universe