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  • The universe has long captivated us with its immense scales of distance and time.

  • How far does it stretch? Where does it end... and what lies beyond its star fields... and

  • streams of galaxies extending as far as telescopes can see?

  • These questions are beginning to yield to a series of extraordinary new lines of investigation...

  • and technologies that are letting us to peer into the most distant realms of the cosmos...

  • But also at the behavior of matter and energy on the smallest of scales.

  • Remarkably, our growing understanding of this kingdom of the ultra-tiny, inside the nuclei

  • of atoms, permits us to glimpse the largest vistas of space and time.

  • In ancient times, most observers saw the stars as a sphere surrounding the earth, often the

  • home of deities.

  • The Greeks were the first to see celestial events as phenomena, subject to human investigation...

  • rather than the fickle whims of the Gods.

  • One sky-watcher, for example, suggested that meteors are made of materials found on Earth...

  • and might have even come from the Earth.

  • Those early astronomers built the foundations of modern science. But they would be shocked

  • to see the discoveries made by their counterparts today.

  • The stars and planets that once harbored the gods are now seen as infinitesimal parts of

  • a vast scaffolding of matter and energy extending far out into space.

  • Just how far... began to emerge in the 1920s.

  • Working at the huge new 100-inch Hooker Telescope on California's Mt. Wilson,

  • astronomer Edwin Hubble, along with his assistant named Milt Humason, analyzed the light of

  • fuzzy patches of sky... known then as nebulae.

  • They showed that these were actually distant galaxies far beyond our own.

  • Hubble and Humason discovered that most of them are moving away from us. The farther

  • out they looked, the faster they were receding.

  • This fact, now known as Hubble's law, suggests that there must have been a time when the

  • matter in all these galaxies was together in one place.

  • That time... when our universe sprung forth... has come to be called the Big Bang.

  • How large the cosmos has gotten since then depends on how long its been growing... and

  • its expansion rate.

  • Recent precision measurements gathered by the Hubble space telescope and other instruments

  • have brought a consensus...

  • That the universe dates back 13.7 billion years.

  • Its radius, then, is the distance a beam of light would have traveled in that time ...

  • 13.7 billion light years.

  • That works out to about 1.3 quadrillion kilometers.

  • In fact, it's even bigger.... Much bigger. How it got so large, so fast, was until recently

  • a deep mystery.

  • That the universe could expand had been predicted back in 1917 by Albert Einstein, except that

  • Einstein himself didn't believe it...

  • until he saw Hubble and Humason's evidence.

  • Einstein's general theory of relativity suggested that galaxies could be moving apart because

  • space itself is expanding.

  • So when a photon gets blasted out from a distant star, it moves through a cosmic landscape

  • that is getting larger and larger, increasing the distance it must travel to reach us.

  • In 1995, the orbiting telescope named for Edwin Hubble began to take the measure of

  • the universe... by looking for the most distant galaxies it could see.

  • Taking the expansion of the universe into account, the space telescope found galaxies

  • that are now almost 46 billion light years away from us in each direction... and almost

  • 92 billion light years from each other.

  • And that would be the whole universe... according to a straightforward model of the big bang.

  • But remarkably, that might be a mere speck within the universe as a whole, according

  • to a dramatic new theory that describes the origins of the cosmos.

  • It's based on the discovery that energy is constantly welling up from the vacuum of space

  • in the form of particles of opposite charge... matter and anti-matter.

  • Back in the 1980s, the physicist Alan Guth proposed that energy fields embedded in the

  • vacuum of space suddenly tipped into a higher energy state...

  • causing space and time to literally "inflate"...

  • ...to go from atomic size... to cosmological size within an infinitesimally short time.

  • As a result, according to one calculation, the universe as a whole...

  • ...would have grown to some ten billion trillion times the size of the observable universe.

  • That's ten followed by 24 zeroes.

  • Put another way, the complete universe is to the observable universe... as the observable

  • universe is... to an atom.

  • The fury of this period of cosmic inflation helps explain the immense size and smoothness

  • of the universe.

  • But to succeed, the theory must also account for how the universe produced what we see

  • around us... all those stars and galaxies and clusters of galaxies, and ultimately...

  • us.

  • Scientists are now seeking to piece together the chain of events that launched our universe

  • in its earliest moments... by generating what you might call a "little bang."

  • At the Brookhaven National Lab in New York State, they are blasting gold atoms in opposite

  • directions down tunnels almost two and a half miles long.

  • When these atoms reach velocities just short of the speed of light, they are sent into

  • a violent collision.

  • A fireball erupts... reaching a temperature exceeding two trillion degrees Centigrade.

  • As far as we know, the last time anything in our universe was that hot was about a millionth

  • of a second after its birth.

  • What interests the scientists is the splatter of subatomic particles... a super-hot soup

  • of quarks and gluons... particles that gave rise to matter as we know it.

  • In initial tests, this quark-gluon plasma has shown a crucial property... extremely

  • low viscosity or resistance to flow. Scientists call this a perfect liquid.

  • To grasp its importance, we go back to those primordial energy fields that the theory says

  • spawned the big bang.

  • The thinking is that those fields contained tiny fluctuations that were blown up to huge

  • size during inflation.

  • In the ultra-dense quark-gluon mix, these fluctuations generated pressure waves, or

  • ripples. As the universe evolved, these ripples led to variations in the density of matter.

  • Amazingly, the imprint of those primordial ripples is out there today... first seen in

  • a faint signal discovered accidentally back in the 1960s.

  • Working for the Bell Telephone Company, physicists Arno Penzias and Robert Wilson had built a

  • giant horn-shaped antenna.

  • But wherever they pointed, the contraption picked up excessive noise in the microwave

  • portion of the electromagnetic spectrum.

  • That noise turned out to match a prediction made years earlier...

  • That in the wake of the big bang, the universe was filled with a cloud of extremely hot gas

  • that scattered all light.

  • As the universe cooled, the cloud dissipated. Light then shone through.

  • Over time it shifted... as the universe expanded and cooled... to just the noise signature

  • detected by Penzias and Wilson. What they'd heard was the echo of the Big Bang.

  • This image shows the smooth contours of the light recorded by the Bell team. Scientists

  • would have to look closer... to find the imprint of cosmic inflation.

  • The Space Shuttle Discovery lifted the Hubble Space Telescope into orbit on April 24, 1990...

  • in one of the most important scientific milestones our time.

  • Another launch, arguably just as important, took place five months earlier.

  • This was the Cosmic Observation Background Explorer, COBE for short, was sent up to take

  • a harder look at the microwave radiation discovered by Penzias and Wilson.

  • The results came out two and a half years later. The early universe contained a pattern

  • of hot and cold spots.

  • One COBE scientist called it the fingerprint of creation... for it showed the origin of

  • the universe we see around us today... smooth on a large scale, but with significant clumps...

  • ...from which gravity would form gas clouds, then stars, and galaxies.

  • With this cosmic template in hand, astronomers set out to discover how the patterns and the

  • dimensions of the universe evolved over time.

  • In an age of computer controlled telescopes and automated observing, astronomers could

  • now launch huge international collaborations with the goal of mapping a large fraction

  • of the universe in three dimensions.

  • At Apache Point in New Mexico, the Sloan Digital Sky Survey set the standard for mass production

  • astronomy.

  • A series of steel plates are drilled with holes that exactly match the location of galaxies

  • in the night sky.

  • After plugging fiber optic sensors into the holes, the plates capture the light of hundreds

  • of galaxies per night, and that light determines their distances from Earth.

  • Another survey is named the 2 Micron All Sky Survey, or 2Mass, after the frequency of infrared

  • light its detectors are tuned to capture.

  • Here, these data go out to a region 60 million light years across. You can see the local

  • group of galaxies, dominated by Andromeda and the Milky Way in the center. This is our

  • neighborhood.

  • Jump further out to a region about 200 million light years across.

  • Our galactic neighborhood merges into the densely packed Virgo Supercluster... which

  • is the nearest intergalactic city.

  • Stepping out to a region over 320 million light years across, you can see the full breadth

  • of our local region of the universe.

  • Galaxies line up in walls and arcs... that bound an array of sparsely-populated voids...

  • the rural cosmic countryside.

  • Moving out with the data... this region is over 650 million light years across...

  • Then almost two billion...

  • 3.2 billion...

  • And finally out to a region 6.5 billion light years from end to end: the cosmic continent.

  • In the middle of it all, our galaxy, so immense from our Earthly perspective, is less than

  • a speck.

  • The 2mass study, the Sloan Digital Sky Survey, and the 2 Degree Field in Australia have extended

  • our maps to a quarter of the way back to the beginning of the universe.

  • They have laid out a grand cosmic roadmap... and gravitational routes.

  • Now COBE's successor, the Wilkinson Microwave Anisotropy Probe, or "WMAP", was ready to

  • scan the early universe for the fine-scale origins of this cosmic atlas.

  • WMAP was launched beyond any interference from Earth... to a position balanced between

  • the Earth and the Sun.

  • There, for two years, its detectors took in the pristine light of deep space.

  • This is what WMAP saw... a pattern consistent with the filaments and voids that had evolved

  • in the universe at large... and with the tiny-scale structures sketched by inflation at the very

  • birth of the cosmos.

  • Scientists at Brookhaven National Lab in the U.S. and the new Large Hadron Collider in

  • Europe will be probing ultra high-energy collisions in the coming years to tease out more details

  • of the early universe.

  • Others are poring over the WMAP data for evidence of its true dimensions.

  • One group looked for repeating patterns that could be evidence of pressure waves that might

  • have ricocheted through the hot gas of early times.

  • They saw none...which implies that the universe had grown so large during inflation that such

  • waves could not cross it.

  • Then they did the math... the entire universe has a minimum diameter of 156 billion light

  • years... not quite twice the size of everything out there that we can see: the "observable"

  • universe.

  • What is its maximum size... and what's beyond that?