FAITH TUCKER: 

	We are sitting on a tiny speck of a planet engulfed in a universe
	that is larger and more complex than we can wrap our heads around.
	Understanding just how our universe came to be the way it is would
	be a much easier task if we could only get outside of the universe
	and watch it mature as an indpendent observer.

	But, that's impossible

	Instead we can only peer out from our little corner of the cosmos
	and do our best to learn about the history of the universe from the
	inside out.

	Starting with those objects that are close at hand and then
	extending our vision outward through space and time.

	The story of modern cosmology began to gather speed when Henrietta
	Leavitt gave the world a valuable tool called the period-luminosity
	relation. Leavitt studied a special group of stars called Cephieds,
	which vary in brightness over consistent periods of time. She
	discovered that there was a relationship between the length of a
	particular star's period from bright to faint to bright again and
	the actual, intrinsic, brightness of that star.

	By combining how bright the star actually is with how bright it
	appears to be on Earth, astronomers were now able to determine the
	distance to such Cephieds.

	While others were looking at Cephieds within our own Milky Way
	galaxy Edwin Hubble applied Leavitt's period-luminosity relation to
	Cephieds he found in the mysterious spiral nebulae.

	Astronomers had been debating for decades whether these spiral
	smudges were distinct, distant galaxies, or merely clumps of stars
	inside the Milky Way. When Hubble determined the distances to many
	of these spiral nebulae, and found that they were located far beyond
	the bounds of the Milky Way, it was finally confirmed that they
	were, in fact, "island universes."

	In one fell swoop, our universe had grown from the cozy confines of
	the Milky Way to an unfathomable expanse of galaxies stretching out
	in every direction. This increasing zoo of distant galaxies,
	combined with Vesto Slipher's pioneering work in measuring these
	galaxy's redshifts, laid the foundation for our understanding of an
	expanding universe populated by billions of galaxies, each
	containing billions of stars.

	With each increasingly distant galaxy, astronomers were seeing
	deeper into space, and farther back into time. The pieces of how our
	universe came to be soon began to fit together to form the Big Bang
	Theory, which claims that the universe began as a hot, dense burst
	of energy that quickly expanded to its current size, and continues
	to expand today.

	In 1965, Robert Wilson and Arno Penzias made the earliest and most
	"distant" observation yet, when they picked up radio static from the
	cosmic microwave background. The CMB, as we call it, is the leftover
	radiation from the Big Bang, and was emitted when the universe was
	only 380,000 years old, which is very early, considering the
	universe is a whopping 13.7 billion years old.

	Today, the Wilkinson Micowave Anisotropy Probe, or WMAP, is
	advancing our knowledge of the CMB and giving us new insight into
	dark energy and dark matter, which appear to play an important role
	in this cosmic drama.

	Our understanding of cosmology and how our universe has reached its
	current state, has certainly come a long way in 100 short years.

	We are constantly learning more as we probe deeper into the heavens,
	from the inside out.

	Finally, I'll leave you with the words of Edwin Hubble

	"For I can end as I began. From our home on the Earth, we look out
	into the distances and strive to imagine the sort of world into
	which we are born. Today we have reached far out into space. Our
	immediate neighbourhood we know rather intimately. But with
	increasing distance our knowledge fades, and fades rapidly, until at
	the last dim horizon we search among ghostly errors of observations
	for landmarks that are scarcely more substantial. The search will
	continue. The urge is older than history. It is not satisfied and it
	will not be supressed."