WWW.ASTRONOMY.COM 29at the same rate. Astronomers observed
the orbit of Mercury to be slightly differ-
ent from what Newtonian physics pre-
dicted, leading some to suggest that an
unknown planet, dubbed Vulcan, might
be perturbing Mercury’s trajectory.
Physicists in 1904 had no idea what
powered the Sun — no known chemical
or mechanical process could possibly
generate so much energy over such a long
time. Lastly, scientists knew various
chemical elements emitted and absorbed
light with specific patterns, none of
which physicists had the slightest idea
how to explain. In other words, the inner
workings of the atom remained a total
and utter mystery.
Although few saw it coming, in hind-
sight, it’s clear that these problems were
heralds of a revolution in physics. And
in 1905, the revolution arrived, ushered
in by a young Albert Einstein and his
new theory of relativity. We now know
that the luminiferous ether does not
exist and that there is no planet Vulcan.
Instead, these fictions were symptoms
of the underlying failure of Newtonian
physics. Relativity beautifully solved
and explained each of these mysteries
without any need for new substances
or planets.
Furthermore, when scientists
combined relativity with the new theory
of quantum physics, it became possible
to explain the Sun’s longevity, as well as
the inner workings of atoms. These new
theories even opened doors to new and
previously unimagined lines of inquiry,
including that of cosmology itself.
Scientific revolutions can profoundly
transform how we see and understand
our world. But radical change is never
easy to see coming. There is probably no
way to tell whether the mysteries faced
by cosmologists today are the signs of an
imminent scientific revolution or merely
the last few loose ends of an incredibly
successful scientific endeavor.There is no question that we have
made incredible progress in understand-
ing our universe, its history, and its ori-
gin. But it is also undeniable that we are
profoundly puzzled, especially when it
comes to the earliest moments of cosmic
history. I have no doubt that these
moments hold incredible secrets, and
perhaps the keys to a new scientific revo-
lution. But our universe holds its secrets
closely. It is up to us to coax those secrets
from its grip, transforming them from
mystery into discovery.Dan Hooper is a senior scientist at the Fermi National Accelerator Laboratory in Illinois
and a professor of astronomy and astrophysics at the University of Chicago. He is author
of At the Edge of Time: Exploring the Mysteries of Our Universe’s First Seconds.The gravitationally lensed quasar
HE 0435–1223 offers an independent
method for determining cosmic
distances. The close-up view reveals
the foreground galaxy that creates the
four nearly identical images of a more
distant quasar. The galaxy lies about
4.8 billion light-years from Earth, while
the quasar resides twice as far away.
NASA/ESA/HUBBLE/S. SUYU (MPIA) ET AL.The European Space Agency’s Planck satellite has captured the best data on the cosmic microwave
background radiation. Combining these results with the standard model describing the universe produces
a Hubble constant that is slightly but unequivocally smaller than that gleaned from nearby galaxies.
ESA/PLANCK COLLABORATION