December 22, 1997
The cosmos is full of spectacular things: ringed planets, exploding suns, rivers of stars across the night.
David N. Schramm 1945-1997
Birthday · December 22, 1997
A little universe, just for you
Your date.
Ready to give.
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APOD published December 22, 1997. Full image credits are on the original APOD entry below. A publication-date match, not a photo taken on your date. Independent of NASA.
David N. Schramm effectively combined the very big with the very small. Among his many scientific achievements, Schramm and collaborators successfully used Big Bang cosmology to predict that only three families of elementary particles exist in the universe, which was subsequently confirmed by high energy particle accelerators. Schramm and collaborators realized that current relative elemental abundance measurements, when combined with nuclear reaction rates, constrain the amount of normal matter to be much less than that implied by the movements of stars and galaxies. Therefore, most of the universe might be made of some sort of dark matter. Schramm was a champion wrestler, a mountain climber, an inspiration to scientists and students, and was alone piloting a plane when it crashed last Friday.