RADIO VOICE: Go ahead, Mikey, push them out of the way if you have to.
JT WILLIAMS: Push 'em out, Mike, push 'em out.
NARRATOR: High above the deserts of Southern Arizona, a team of scientists is about to unveil a new secret weapon. But first they have to get it up the mountain. Engineer JT Williams is in charge of protecting the 25-ton cargo.
JT WILLIAMS: Around this next turn we'll be clearing the guardrail by inches.The whole trick is not to stop.
NARRATOR: With every hairpin turn, disaster looms. Finally, the summit of Mount Hopkins, and the 10-million-dollar package can be unwrapped.
JT WILLIAMS: Yes! Everybody get your hands on the mirror. Don't let that sucker move. Okay! Going up.
NARRATOR: Dozens of suction cups grasp the object.
JT WILLIAMS: Steady!
VOICE: Okay now, hold onto it. It's going!
NARRATOR: A colossal mirror—23 feet across. A crane lifts it a hundred feet into the air and lowers it into its new home—an enormous telescope. It is destined to play a key role in a dramatic new quest to hunt down evidence of a mysterious force lurking in outer space.
Already, the discovery of this force is shaking the very foundations of scientific thinking.
WENDY FREEDMAN: These results have enormous implications. And if they are correct, it really will revolutionize our understanding of what the universe is like and how it came to be.
NARRATOR: This strange force was predicted by Albert Einstein, who later discarded the idea. Now, his bizarre theory is suddenly back in fashion, as scientists rethink their vision of our universe and its ultimate fate.
BRIAN SCHMIDT: In the distant future there will be nothing in the universe left to see, there will just be us. And that seems to me to be the coldest, most horrible end. This universe is weird. It's creepy.
NARRATOR: The world of astronomy is in an uproar about the possibility of a Runaway Universe.
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NARRATOR: A long time ago, in a galaxy far, far away, a star is about to die, but not quietly. It will go out in a blaze of glory, a thermonuclear blast more powerful than five trillion, trillion atomic bombs—a supernova.
Billions of years later a tiny fraction of that light hurtles toward a small planet, where a band of Earthlings eagerly awaits its arrival.
BRIAN SCHMIDT: Because they're going to get hammered with the sky brightness.
NARRATOR: Their leader is Brian Schmidt, one of the world's foremost supernova hunters.
BRIAN SCHMIDT: Yes, what's the problem with...
NARRATOR: Growing up under the big skies of the American west, Brian has always been fascinated by the stars.
BRIAN SCHMIDT: A fundamental question to me, as a child is (sic), what was the beginning of the universe? What is the end of the universe? I mean, I cannot think of a more fundamental question for humankind, you know, to ask: What is the ultimate fate of
NARRATOR: Today, Brian is finding some unsettling answers that would have shocked scientists of the early 20th century.
A hundred years ago, astronomers believed the universe consisted of nothing more than a disk of stars and gas we know as the Milky Way Galaxy. They saw a cosmic landscape dotted with giant regions of luminous gas. And stars, like our own sun, swirling around within the galaxy. But the overall size and shape of this island universe seemed static—stable and unchanging.
That was a problem for one physicist trying to make sense of it all. Albert Einstein knew that gravity worked to draw matter together. Left alone, everything would move closer and closer, until the entire Universe collapsed in on itself. Since that hadn't happened, Einstein reasoned that there must be some other force, a kind of anti-gravity, that held matter apart and kept the Universe in its static state.
He called this repulsive force the "cosmological constant."
MICHAEL TURNER: Einstein introduced the cosmological constant as a fudge factor. He thought he knew the answer at the back of the book. He thought that the universe was static and so he put in this fudge factor. And this is kind of one of the neat things
NARRATOR: Einstein tried to put the genie back in the bottle. Realizing that new discoveries had made it obsolete, he called the cosmological constant the greatest blunder of his career.
The new wave of discoveries began in 1917, on the summit of Mt. Wilson in California, where engineers assembled a powerful telescope. Edwin Hubble used the new instrument to study distant, cloud-like objects called nebulae. He found that some nebulae were so far away, they must lie beyond the Milky Way.
In fact, they were entire galaxies similar to our own extending far out into space. These galaxies were moving away from us and each other. By 1929, the news was out: the universe was larger than anyone thought, and it wasn't static. It was getting bigger every day.
WENDY FREEDMAN: Hubble showed that the universe is expanding. That led to this idea of a big bang universe. That is, if galaxies have been expanding and we see them expanding now, then they must have been closer together in the past, and there must have been a time when the universe would have been very dense, would have also been very hot, and along with the general theory of relativity developed by Albert Einstein, this led to this picture of the Big Bang universe.
NARRATOR: The big bang—the giant fireball that gave birth to our universe. The blast generated so much momentum that it's driven the expansion of the universe for 15 billion years. Over the eons, gravity has worked against that outward thrust, drawing gas into a vast web of matter, where galaxies and stars are born. Astronomers have long believed that all the matter in the universe—and all the gravity it exerts—should slow the expansion down. With enough gravity, the expansion could stop completely, and then the universe will implode.
BOB KIRSHNER: Maybe a universe that had a lot of matter in it would expand for a while, turn around, and then contract at sometime in the future. So it would start out with a big bang. We're 15 billion years from the big bang. And then at some very distant time in the future you can imagine a kind of Big Crunch, or Gnab Gib, I like to call it. big bang backwards, which is the crunching together of the universe.
NARRATOR: In recent years, astronomers have been trying to measure how much the cosmic expansion has been slowing down.
ALEX FILIPPENKO: The original goal of our project was to measure the rate at which the expansion of the universe is slowing down. When you throw a rock in the air, the gravity of the Earth tends to pull it down and it slows down that rock as it is rising
NARRATOR: But how do you precisely measure the speed of something as vast as the universe? About a decade ago, scientists discovered that one kind of celestial object might serve as an ideal cosmic speedometer: An exploding star, called a supernova.
What makes a supernova so special is its incredible brightness. It can be seen billions of light years away and some supernovae seem to be remarkably uniform. Like cars with identical headlights. The farther away they are, the dimmer they appear. Because their brightness is so consistent, supernovae can act as mileage markers. Astronomers use them to chart the movement of galaxies halfway across the visible universe. But first they have to find them.
That's the challenge facing Brian Schmidt and his team, as they gather on a barren summit in the Andes Mountains of Chile.
BRIAN SCHMIDT: Okay now that is new, that looks quite thin.
NARRATOR: Supernova explosions are rare events. In any given galaxy, one will blow up perhaps every 100 years.
NICK: Well, there's one right here.
BRIAN SCHMIDT: Yes, it looks like two colliding galaxies there. Kind of interesting to look at. Good place to find a supernova.
NARRATOR: It's a needle in a cosmic haystack, and to find one, Brian has to survey thousands of galaxies at once.
ASTRONOMER: Cinco al sur y cinco este.
NICK: Hold your breath.
BRIAN SCHMIDT: Oh, I am.
BOB: Okay, exposure starting.
NARRATOR: For the next three nights, he'll use the telescope to take hundreds of photographs, each one focusing on a patch of sky about the size of the full moon.
NICK: It was a thick chip before.
BRIAN SCHMIDT: Okay, you're right. So, it's a bit better.
NARRATOR: As the new images come in, they're compared electronically to a set of pictures taken months before.
BRIAN SCHMIDT: Everything is a galaxy. We have to really hunt for stars.
NARRATOR: The computer looks for subtle differences. If it detects a bright spot that didn't exist before, then the team may have found a coveted supernova.
BRIAN SCHMIDT: I'd be a little suspicious of that one guys.
NARRATOR: Or not. The computer's discriminating powers are not very subtle. So, with the images now in hand, it's up to the human scientists to look at the candidates and choose or guess which are the real supernovae.
ASTRONOMERS: Asteroid. Asteroid.
PETE: Supernova? Or world's slowest moving asteroid?
BRIAN SCHMIDT: Who knows? These mystery objects always get me.
NARRATOR: Even if they do find a supernova, it might not meet Brian's exacting standards.
PETE: There's this thing over here.
BRIAN SCHMIDT: Oh. That's pretty clear.
PETE: That's a whopper.
BRIAN SCHMIDT: Right there.
PETE: Look at that.
BRIAN SCHMIDT: That's nearby.
BRIAN SCHMIDT: Yeah, big one. Unfortunately, bright but not so interesting. But that's all right.
PETE: Why is that not interesting?
BRIAN SCHMIDT: Because it's got to be nearby and probably pretty old.
NARRATOR: Brian needs to be fussy. The experiment calls for supernovae that have not yet reached their peak intensity and are extremely far away.
BRIAN SCHMIDT: We want faint objects. We want the ones that are not so hard that they are almost impossible for a telescope to see, but we want them sort of faintish. We want them at a certain distance, and that certain distance, that magic distance for u
NARRATOR: Frame by frame, hour after hour, the team slogs on, eyes glued to their monitors.
PETE: More noise spikes.
ASTRONOMERS: ...Nothing....I don't see anything in this...okay...sorry guys, no....Just junk....
PETE: Uh, nothing here.
BRIAN SCHMIDT: We work until we have to go to sleep. And you know, some people last longer at it than others. And you just keep on pounding away, looking at frame after frame after frame. And there's a lot of frames, and so, yeah, it does feel like a grind.
NARRATOR: Every member of the team feels the pressure. They all know that a rival group of supernova hunters is waiting in the wings, eager for their turn at the Chilean telescope. The competing team is led by Saul Perlmutter, who's spent much of the last decade developing techniques for finding the elusive explosions.
And it's nerve-wracking. Even if a supernova is the right age and distance, it still may be the wrong kind. The hunters are looking for a very special breed of exploding star: the Type One-A supernova. Like this one, captured by the Hubble Space Telescope in 1994.
Until their demise, they live like ordinary stars, gradually consuming the hydrogen gas that makes up their cores. As the end nears, the star swells and sheds its outer layers, leaving behind a small dense sphere the size of our Earth, called a White Dwarf. Most of these stars burn out peacefully but under certain circumstances matters get out of hand.
The most violent scenario occurs when the White Dwarf orbits another kind of dying star, called a Red Giant. The Giant swells, nearly touching the smaller star. The two then begin a dance of death, as the White Dwarf draws hot gas from its partner. The Dwarf's mass increases, but at a certain point, it can grow no further. And it goes supernova.
ALEX FILIPPENKO: If there were people on the planet orbiting a White Dwarf that is about to explode, those people should really try to find another home. They are going to get much, much more than just a bad sunburn, okay? They are going to get fried to a
NARRATOR: It is the Type One-A supernovae which explode in the most consistent and predictable way. But as the supernova hunters know, tracking them down can be a mind-numbing process.
ASTRONOMER: You're going to go to the next -
PETE: Yes, I'm going to the next chip.
ASTRONOMER: That was a dud, wasn't it?
NARRATOR: Thanks to their persistence, and gallons of potent Chilean coffee, the supernova search is starting to yield some results.
BRIAN SCHMIDT: Hey, I like this one. Right here. Before, after, before, after.
ASTRONOMERS: Yes, nice one. Right there. Very nice one.
BRIAN SCHMIDT: All right.
ASTRONOMER: Sure, solid.
BRIAN SCHMIDT: So, that's probably a star that's been waiting five billion years to get to us. A lot of people have thrown in the towel on this question.
NARRATOR: After a few days, the team has located about two dozen promising candidates just in time for the arrival of Brian's mentor, astronomer Bob Kirshner.
BOB: I like that one.
BRIAN SCHMIDT: I like that one too.
BOB: That's a good one. Find it right next to that star. What is this?
BRIAN SCHMIDT: This is a big bright puppy.
BOB: What is this one?
BRIAN SCHMIDT: Yes, this is a good one, I like it. Now wait till you see the next one.
BOB: Alright, jeez.
BOB KIRSHNER: One of the things that's fun about working on supernovae is they happen pretty fast. Most astronomical things don't change in a human lifetime. They don't change in a million. But a supernova changes in a week. Changes in a month. It really is very exciting to watch these things happen, and it's a lot of fun...I can't quite tell what's going on.
BRIAN SCHMIDT: It's actually very ...
BOB: Because the galaxy makes it noisy.
BRIAN SCHMIDT: It's very faint, and it's in a galaxy.
BOB KIRSHNER: Everything has to work right to get data as good as this. I mean lots of things can go wrong. You can have trouble with the weather, or you could have a computer problem. You could have electronics problems, the telescope could malfunction. It sometimes does. So to have everything go right and as right as this you are really lucky, and it's great.
BRIAN SCHMIDT: Well, they're still going to twenty-three and a half....
NARRATOR: In the end, the team in Chile achieves its goal. They identify 35 possible supernovae.
BRIAN SCHMIDT: And it's sort of off to the side here, of this fairly brightish galaxy.
NARRATOR: But the true test of their labors will come just a few days later, when the candidates will be scrutinized by the most powerful telescope on earth. Seven thousand miles from the Andes Mountains, two of Brian's colleagues rendezvous in Hawaii.
They've come to use the world-renowned Keck Telescope, located high atop the Mauna Kea volcano. While the equipment in Chile was ideal for photographing relatively large swatches of the sky, the Keck Telescope's 33-foot mirror can focus on a single, very distant object.
Adam Riess and Alex Filippenko will use Keck's awesome viewing powers to take a closer look at Brian's list of candidates. They've been allotted just five nights to analyze 35 objects and find out if any are truly supernovae, specifically, if they're Type One-A's.
In the days before their arrival, they hope for good weather. But driving up to the 14,000-foot summit, Adam and Alex can barely see the road ahead through the thick, gray fog.
ALEX FILIPPENKO: Once I was here when it was a very thick layer, all the way from HP, up to about the summit. So it was a over a mile thick
NARRATOR: If they can't see the sky this week, then the work in Chile will all be in vain.
ALEX FILIPPENKO: Well, let's hope for the best. We have five big nights coming up. This is a big campaign for our project, right?
NARRATOR: Luckily, as they approach the summit, the clouds break, and blue sky appears overhead. Alex and Adam head inside, to the Keck's control room.
ALEX FILIPPENKO: Okay, so let's go and do the offset to the supernova which is 40.01 east and 8.83 arc seconds north.
NARRATOR: The first task is simply to point the telescope directly at one of the supernova candidates. It's not as easy as one might think. Often, the objects are so dim and distant they don't show up on the monitors.
Without a visual confirmation, they have to trust the coordinates sent from Chile by Brian. To find out if he's looking in the right place, Alex has to wait for a long exposure at least 20 minutes and sometimes an hour to allow enough light to filter through to the telescope.
ALEX FILIPPENKO: The problem is I like to check the offsets just to make sure they're okay before we do this blind exposure.
NARRATOR: If the position is even slightly wrong, the telescope's tiny aperture will miss the object completely.
ALEX FILIPPENKO: So it just makes me nervous. In five minutes we'll know.
NARRATOR: The astronomer's biggest fear is that they will waste precious telescope time taking pictures of empty space.
ALEX FILIPPENKO: Okay, so about a minute to go. Do you think we got it?
ADAM RIESS: Yeah.
NARRATOR: It's the moment of truth for Alex and Adam.
ALEX FILIPPENKO: Okay, here we go. Is it there or is it not? Hey it's there! We got something. There's a signal there. Okay, let's keep on exposing.
ADAM RIESS: Yes, it's pretty weak.
ALEX FILIPPENKO: Yeah, it's pretty weak, but it's there. It's on the slit.
NARRATOR: Once they've collected enough light from the object, the data goes through another set of computers manned by Doug Leonard, down at sea level.
DOUG LEONARD: Hey Alex, this looks like a really good one. It looks like a good One-A, it's probably a redshift a half.
ALEX FILIPPENKO: Hey all right! Can you send the spectrum over to Adam?
DOUG LEONARD: Yes, I'm sending it up.
NARRATOR: The telescope breaks down the supernova's light into the full color spectrum, much as a prism splits white light into the colors of the rainbow. But this spectrum shows up as a graph. Each peak and valley corresponds to a different chemical roaring out of the explosion.
ADAM RIESS: In the atmosphere of a supernova are certain elements: sulfur, calcium, iron, things like this. So this dip here is due to silicon in the atmosphere. And this long dip here is due to iron in the atmosphere of the supernova.
NARRATOR: The thermonuclear reactions generated by supernovae make them, literally, atomic blenders. The early universe contained little more than hydrogen and helium. Supernovae explosions put together new combinations of protons, neutrons, and electrons, creating the heavier elements that make up our Earth and ourselves. A Type One-A supernova has a very specific mix of elements, a clear signature that will show up in the spectrum.
ADAM RIESS: The white thing is the spectrum. And the red thing is the spectrum of a classic Type One-A supernova at its maximum brightness. Feature for feature, it's a very similar sort of thing here.
NARRATOR: Once Adam and Alex determine that the distant object is in fact a Type One-A supernova, the next step is to look for what astronomers call the redshift.
Back in the 1920s, Edwin Hubble compared the color spectra of different stars and galaxies. He discovered that the more distant an object is, the redder it appears. This shift in color occurs because distant objects are rapidly moving away from us.
ALEX FILIPPENKO: When stars in a galaxy emit light that is traveling toward us, and space itself is expanding during that journey, the actual wavelength of the light, you know that light can be thought of as a wave, it actually stretches. It expands. And this fundamentally is what produces the redshift. If a blue wave in its journey from the star toward us stretches, it turns into a red wave—a wave of a longer wave length, and that is what we perceive as red. It's also a case where we need enough objects to be able to....
NARRATOR: Today, this redshift is recognized as the best way to measure the speed of a distant object as it travels through the cosmos.
ADAM RIESS: What happens later it...this feature right here...
ALEX FILIPPENKO: This little notch develops.
ADAM RIESS: Right
NARRATOR: The very first supernova candidate is a classic Type One-A, but Alex fears that it might be past its prime, and of little use to the study.
ALEX FILIPPENKO: So, this wouldn't be bad, but I think we should hold out for a possibly better one. So I think we should move on.
ASTRONOMER: Okay, I'm guiding.
NARRATOR: They do move on, but the night is filled with frustration.
ALEX FILIPPENKO: Let's see. This is a very strange object.
ADAM RIESS: This is a head-scratcher. I don't know what the heck's going on.That looks awful.
ALEX FILIPPENKO: That looks awful. It's not something I can easily recognize. Oh yeah it is. That's definitely a supernova.
ADAM RIESS: These are really narrow though, aren't they, for a Type One-A?
ALEX FILIPPENKO: Well, we're striking out if this isn't the One-A—this makes absolutely no sense at all. Why are we getting all these weird ones?
NARRATOR: Luckily, on the second night, things take a turn for the better.
ALEX FILIPPENKO: I think I see it. It might be right there.
ADAM RIESS: Looks pretty strong.
ALEX FILIPPENKO: That's not a bad signal actually.
ADAM RIESS: Yeah, it's quite strong. I think it's the strongest thing we've seen tonight.
DOUG LEONARD: Hey Alex, it's uh, it looks like a great One-A, probably a red shift about one half.
ALEX FILIPPENKO: Is the spectrum over to where Adam can plot it?
DOUG LEONARD: Yes.
ALEX FILIPPENKO: Okay.
NARRATOR: Finally, a winner.
ADAM RIESS: Hey, look at that.
ALEX FILIPPENKO: Oh, you've got it already!
ADAM RIESS: Wow, that is nice.
ALEX FILIPPENKO: Oh man, this is the best one of the run.
ADAM RIESS: Alright, let me see if, uh ...
ALEX FILIPPENKO: Look at this thing.
NARRATOR: Brian Schmidt's team in Chile screened tens of thousands of galaxies and came up with 35 potential Type One-A's.
ALEX FILIPPENKO: Oh, this is a winner.
ADAM RIESS: The express (?) wavelength is 4300.
ALEX FILIPPENKO: This is the best one we've had so far.
ADAM RIESS: This is the one we send to Hubble.
ALEX FILIPPENKO: Absolutely.
NARRATOR: After five nights of intense analysis, Alex and Adam have whittled the field down to two.
ALEX FILIPPENKO: Yes, there's ours.
NARRATOR: These are the cream of the crop—good enough for further study by the Hubble Space Telescope.
ALEX FILIPPENKO: This one here looks the most different of all.
NARRATOR: Launched in 1990, the Hubble can view the cosmos unobscured by Earth's distorting atmosphere. As a result, its photographs of distant stars and galaxies are spectacularly sharp. The team needs this clarity to measure precisely the brightness of their selected supernovae. From this, they'll calculate their distance from Earth. Knowing the distance and speed of these cosmic mileage markers gives astronomers a crucial tool. It will allow them to calculate not only how fast the universe is expanding, but will offer a clue to its ultimate fate.
Several months will pass before they find out what the supernovae are trying to tell them. And even then, they won't believe it. The team expected the supernovae to confirm that the expansion of the universe was slowing down. But when the results finally came in, something seemed terribly wrong.
ALEX FILIPPENKO: Well, the other thing that worries me is that these are very narrow features right here.
Adam Riess and I were analyzing the results and Adam made a graph of brightness versus the redshift of a supernova and the dots, the data fell along a curve in the graph that did not indicate that the universe was slowing down in its expansion. It indicated that the universe is speeding up. And my jaw just dropped.
NARRATOR: The data showed that the distant supernovae were dimmer and therefore much farther away than the team expected. Instead of slowing down, the expansion of the universe has been speeding up with galaxies moving apart at greater and greater velocities.
ADAM RIESS: I was actually scared that I had made an error. One by one, we started checking off sort of a long list of possible errors and none of them seemed to be the case. Finally, we had to come to grips with this unusual result. I no longer looked at it as a likely mistake, but rather as something very bizarre that nature was trying to tell us.
NARRATOR: The bizarre message was that the Universe is accelerating. For the team's leader, Brian Schmidt, the results were especially difficult to swallow.
BRIAN SCHMIDT: It was not something that I particularly wanted to be in my data. And so I was horrified because I knew that it was going to be very difficult to sell this to my colleagues, because my colleagues are the ones who have educated me, and they
NARRATOR: Brian's colleagues, along with the entire scientific community, might have discounted his results, except that Saul Perlmutter's group—working separately—announced the exact same conclusion.
The discovery seemed to contradict everything we thought we knew about gravity and its impact on galaxies and stars.
ALEX FILIPPENKO: If our discovery is correct, it suggests that the universe is beginning to accelerate in its expansion, to go faster and faster. Now this is really reminiscent of what we think the universe went through in its first tiny fraction of a sec
NARRATOR: What could possibly be causing the whoosh? Something must be countering gravity, pushing all the galaxies apart, some mysterious repulsive force, unlike anything we've encountered on Earth. The thought of such a form of energy is strange, but it's not new. It sounds like Einstein's old idea, the cosmological constant, which he had so famously called his greatest blunder. Now, it seems Einstein may have been right after all.
ALEX FILIPPENKO: If Einstein heard these results today, he would say, "Yahoo!" It would be such a thrill for him, I think, to see that his original prediction that such a weird stuff might exist in the universe turned out to actually be true.
NARRATOR: But what is this weird stuff? Scientists have different names for it: vacuum energy, dark energy, quintessence. But they have little idea of what it consists of or where it comes from. One highly speculative theory is that the force comes, quite literally, from nothing.
STEVEN WEINBERG: Now this is pretty mysterious. It is an energy that is present everywhere in space. We are normally not aware of it. There is no way of tapping into it that we can imagine.
You know empty space is not so empty. In empty space there is a continuous creation of particles, matter and anti-matter, continually being created in pairs and destroyed. It is a seething stew of particles and radiation whose effects we can sometimes observe.
NARRATOR: The idea is that in empty space, tiny, subatomic particles pop in and out of existence. On the cosmic scale of the universe, all these popping particles add up to produce a peculiar form of energy which actually stretches space, pushing it outward.
MICHAEL TURNER: The cosmological constant that we have in mind, that may be explaining why the universe is speeding up, is just the tiniest little bit of energy. And so you might wonder how can it, you know, cause the universe to speed up and get bigger?
BRIAN SCHMIDT: The basic idea is this sort of energy permeates all of space, and it has some very different properties to what you and I are made of. It is not atoms. It is actually something that you can't even get a hold of. But it does have a fairly profound effect on the universe as a whole, which is it causes space to accelerate from itself.
NARRATOR: Strange as it sounds, this is not the first time that scientists have found evidence that behind the visible features of the universe lurk unseen and profoundly mysterious forces. Since the days of Hubble and Einstein, astronomers have explored the contours of the universe, mapping landscapes shaped by the force of gravity. Gravity binds our sun to a hundred billion other stars—interspersed with pockets of dust and gas—in a vast rotating spiral we call the Milky Way galaxy.
But things are not always what they seem. The galaxy is spinning so fast that centrifugal force should have flung the stars into space. All the matter we can see does not exert enough gravitational pull to hold the galaxy together. There has to be something else there. But it's completely invisible.
Beyond our galaxy, the mystery only deepens. Gravity ties our galaxy to a group of thirty others within a distance of three million light years—our cosmic neighborhood. This "local group" is bound to a still larger region. It is fifty million light years away—the ten thousand galaxies that make up the Virgo Supercluster. These galaxies move so fast that some unseen presence must be holding them in.
Scientists call it "dark matter," a strange form of matter that exerts gravity but does not emit or reflect light. Little else is known about dark matter, except there's a lot of it. In the regions of space we can see, there seems to be ten times more dark matter than ordinary matter. And now, there's another mysterious ingredient in the universe—dark energy.
WENDY FREEDMAN: Now we are being confronted with the possibility that not only is there matter that we know nothing about, but there is another kind of energy that we know absolutely nothing about. The best theories don't predict that it should be there. And so, what is going to be the challenge in the next century is to understand what is the nature of that dark matter and that dark energy. And these experiments that are now going on are going to help us understand what is the amount of that dark matter and dark energy, and ultimately what it is, if it is there.
NARRATOR: Even if astronomers can't yet identify the exact nature of dark energy, there may be a way to confirm its presence. Dozens of teams are now heading into the field in a far-flung international race to dissect the contents of the universe.
This team, based at the University of California and the University of Minnesota, will send a telescope mounted on a balloon twenty-five miles high, to the top of the Earth's atmosphere. From there, the telescope will take a snapshot of the early universe by recording what's called the cosmic background radiation. This microwave signal emanates from all of space, and scientists believe it is the vestige of a time early in the history of the universe, 300,000 years after the big bang. At that point, the universe had cooled down just enough to allow atoms to form, and light waves were first able to travel through space.
NARRATOR: Those slight differences correspond to the very earliest bits of matter, clumping together in irregular patches. These patches would eventually form regions of stars and galaxies.
By measuring the size of the patches, the balloon team hopes to calculate how much matter and energy exist in the universe. For its lofty mission, the balloon is outfitted with the most technologically advanced sensors available. But it's held together with bits of duct tape and sheet metal...an astronomical road warrior. The information will be radioed back to Earth, in case the telescope crashes on landing.
ADRIAN LEE: When it lands it's like taking this whole package and just dropping it off a one-story building without any protection. But we have flown this twice. It's flown and landed in good shape both times.
NARRATOR: As the balloon is filled with helium, anticipation and anxiety grow. Finally, we have lift-off and it's flawless.
SHAUL HANANY: That's beautiful. It's really pretty. Wow, this is so beautiful, so graceful.
NARRATOR: The balloon sets sail for its lookout on the primordial universe.
VOICE: It's so awesome, it's scary...
PAUL: That's what you do all that work for...
VOICE: Now we do some real work...
PAUL: What? What work? I want to go celebrate.
NARRATOR: The balloon rises into the stratosphere. The decrease in air pressure will cause it to swell to 500 feet across. As currents carry it through the night, data streams back to Earth.
Over the next year, the Berkeley team uses the observations and an army of supercomputers to produce an accurate map of the infant universe. The result: a pattern that reveals a universe containing far more energy than astronomers had previously been able to detect.
VOICES: Sure, it's not in bad shape considering the landing it had.
No, I think we have something.
NARRATOR: In the years ahead, the Berkeley group's data will be checked by an intensive international effort, relying on special American and European space telescopes. If the dark energy does account for two-thirds of the contents of the universe, then it may be the dominant force in the cosmos.
NARRATOR: Not everyone is convinced of this new vision of the universe.
SAUL PERLMUTTER: And right there is the supernova and as you come back out again, you can see that it....
NARRATOR: Some of the biggest skeptics are the supernova hunters themselves.
SAUL PERLMUTTER: That is much broader than the location of the supernova.
NARRATOR: So much is resting on their results, they know they have to double and triple check them.
SAUL PERLMUTTER: All right, so there's the supernova clearly, right?
BRENDA: And the supernova comes booming through right here.
WENDY FREEDMAN: These results have enormous implications - it is radical finding. And if they are correct it really will revolutionize our understanding of what the universe is like and how it came to be. And by the same token, if you are going to have a radical claim like that you really better have very stringent tests and determine whether or not there are other explanations for the result you're seeing.
NARRATOR: Is the light of each Type One-A really the same, like identical headlights on a highway? Perhaps the universe is playing tricks on our eyes—even dimming the supernova's appearance with unseen cosmic dust.
In the meantime, astronomers are trying to come to grips with the possibility that the accelerating universe and its mysterious repulsive force are here to stay.
BRIAN SCHMIDT: This universe is weird. Not only is it infinite. I can live with that. Seems to me space has to be infinite, but this is a universe which is going to accelerate faster and faster over time. So that if I were born 10 million years from now, I would see a lot less of the universe than I see now.
The universe might be expanding so fast now that in the distant future there will be nothing in the universe left to see. There will just be us, our single Milky Way Galaxy, the Andromeda Galaxy with us. All by ourselves with nothing else around. And that seems to me to be the coldest, almost horrible end to the universe that I could think of. It is...it is just...I don't know. It's creepy.
NARRATOR: In the years to come, both supernova teams will study the exploding stars in greater detail, to find out if they can really be trusted.
The new telescope on Mount Hopkins will play a crucial role in that ongoing effort. Finally outfitted with its giant mirror, it's now ready for a landmark event. A handful of observers has gathered to witness the telescope's first images, what astronomers call First Light. Among them is supernova hunter Bob Kirshner.
BOB KIRSHNER: This telescope is really important to what we're doing. It's a big telescope, six and a half meters, so it collects a lot of light. And it's going to make beautiful images with this very smooth mirror. We're going to be able to make better measurements of the distant supernovae with a telescope like this than we've been able to do before.
NARRATOR: For its first run, the telescope is equipped with a small test camera, but still, expectations are high.
BOB KIRSHNER: Well, with the big camera we'll be able to do big chunks of the sky. Maybe we'll search for supernovae with that. And you'd see hundreds of galaxies like that or much fainter, but you'd see hundreds or even thousands of the distant galaxies. That would give you a good chance, for example, of seeing a supernova in one of those any night. Every picture you take will have a supernova in it. Course, the trick is to find it.
NARRATOR: In the years to come, much will be riding on the powers of this telescope.
ASTRONOMER: It could change if we lose an index.
CRAIG: Okay, have you guys got an object to go to?
NARRATOR: Suspense builds as the minutes tick by.
CRAIG: There it is, there's something. Wait, just leave it right there for now. Leave it there.
NARRATOR: Finally, First Light filters through.
CRAIG: Whoa, whoa, whoa! That is good. It's the jet!
NARRATOR: An explosion of particles shoots out from a gigantic black hole in the Virgo Supercluster.
CRAIG: Hey did you see this? It's the jet in M87.
NARRATOR: The image is all they had hoped for: clear and sharp, even though the subject is 50 million light years away.
Many astronomers believe this is a golden age of cosmology, when technological advances will help answer fundamental questions that have puzzled humankind for centuries. Already, a new glimmer of understanding has come from across the depths of space: the final gift of a dying star.
Find your place in the universe. Take an amazing journey on NOVA's Web site, from our home here on earth to distant galaxies millions of light years away, at PBS.org or America Online Keyword "PBS."
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