YSM Issue 96.4

FOCUS
Cosmology
REDISCOVERING
COSMIC ORIGINS
THE BIRTH OF THE SOLAR SYSTEM
BY DAVID GAETANO | ART BY ANNLI ZHU
It is easy to take for granted the vast scope
of scientific understanding that humans
have acquired over hundreds of thousands
of years on Earth. Today, for example, the
origin of the solar system is relatively well
understood. But not too long ago, we were
searching for an answer among a sea of
endless theories.
An article from the 1941 edition of the
Yale Scientific Magazine (Vol. 15 No. 4), titled
“The Origin of the Solar System,” is a time
capsule that provides a firsthand account of
the scientific community’s understanding
of the solar system’s origins at the time. The
writer, Lyman Spitzer Jr., was a well-respected
Yale faculty member who earned his PhD
in physics from Princeton University in
1939. In his piece, Spitzer sought to analyze
contemporary understanding of the origin
of the solar system and place doubt on the
existing theories of the time.
Eighty years later, this article revisits
Spitzer’s analysis. By reflecting on evolving
scientific understanding, we can help
provide motivation for further scientific
advancement, as the cosmos still leaves much
to be discovered.
Early Theories
“The rise and subsequent decline of the
most important theories of the origin of the
solar system are an instructive chapter in
the history of science and cast light on the
problems which an ultimately successful
theory must face,” Spitzer wrote. At the time
of his article, there were many different
hypotheses surrounding the formation of
the solar system, yet none could truly be
rigorously proven. In fact, Spitzer criticized
two of the leading hypotheses for their lack of
concrete evidence.
The first theory he analyzed was the
nebular hypothesis, which argued that the
sun was first created out of a huge, rotating
cloud of gas and dust in space, which was
then flattened into a disk. This disk would
have subsequently condensed to form the sun
and various planets seen in the solar system
today. He argued that this hypothesis was
impossible due to the conservation of angular
momentum, which means that the sun would
12 Yale Scientific Magazine December 2023 www.yalescientific.org