Mapping the Cosmos
Astronomers Astonished at What They're Learning

Monday, May 25, 1998
(This is an unedited, uncorrected transcript.)

FORREST SAWYER, ABC NEWS (VO) Eight years ago, the near-sighted Hubble space telescope was the most expensive piece of space junk in the universe. And then ...

WENDY FREEDMAN, CARNEGIE OBSERVATORY It made an enormous difference, like putting on a pair of eyeglasses. Suddenly we could see the universe very clearly.

FORREST SAWYER (VO) Now repaired, the Hubble telescope has opened a window to the deepest mysteries of the cosmos-black holes, dark matter, quasars, colliding galaxies.

ROBERT KIRSHNER, HARVARD SMITHSONIAN ASTROPHYSICS We're just getting an early glimmer of what's going to turn out to be the real story of how the universe is constructed.

VERA RUBIN, CARNEGIE INSTITUTION We live in a fairly mysterious universe. I think there are enormous surprises that are still in store.

FORREST SAWYER (VO) Tonight, mapping the cosmos, answering questions and questioning the answers.

ANNOUNCER From ABC News, this is Nightline. Substituting for Ted Koppel and reporting from Washington, Forrest Sawyer.

FORREST SAWYER Choose the qualities that define mankind and high on the list is curiosity. For as long as we can remember, and surely much longer than that, we have looked up at the night sky and wondered what we were seeing, and we've always managed to come up with answers. The twinkling lights are lanterns or gods, perhaps. And those answers have always turned out to be wrong. And now, just when we thought we were getting a grip on things, the Hubble space telescope is coming up with yet stunning new information. In fact, we're sitting smack in the middle of a revolution in the sky, with scientists pummeled by new data forcing them to rethink, well, everything.
So we thought maybe it's about time to take a look at why astronomers these days are shaking their heads in astonishment at what they're learning. And we thought our senior science correspondent, physicist Michael Guillen, would be the perfect tour guide. Maybe after Michael's through, the next time we go stargazing and figure we know what we're seeing, we'll think again. Maybe the universe is not only stranger than we know, it's stranger than we can know.

MICHAEL GUILLEN, ABC NEWS (VO) From very far away and a long time ago, comes this image of a collision between two galaxies, so violent, so tremendously powerful, all the dust and gaseous debris was literally set on fire. And a thousand times more brilliant still, this picture of a quasar, brightest object ever discovered. Elsewhere, inside this huge, towering incubator, another star was being born while these newly hatched galaxies came to life somewhere in the outskirts of the visible universe.

RICHARD BERENDZEN, AMERICAN UNIVERSITY We can see objects whose ghostly remnant has traveled for billions of years. They are so far away, some of them have died. We're seem them not as they are, but as they were.

MICHAEL GUILLEN (VO) By piecing together these childhood pictures of the cosmos, these snapshots of what it used to look like, many astronomers now believe they're on the verge of understanding how the universe came to be.

ALAN GUTH, MIT The data is coming in so fast now that it really does look like in a period of five to 10 years, all of the big mysteries now are very likely to be resolved.

MICHAEL GUILLEN (on camera) Ever since we've lifted our eyes to the night sky we've marveled at all those shimmering points of light and wondered what lay beyond. With our powerful ground-based telescopes, we've discovered the answer. There are even more little points of light, many of which are full blown galaxies just like ours-100 billion galaxies in all each containing about 100 billion stars.
(VO) With our space-based Hubble telescope, we've discovered even more surprising things about galaxies, although it took awhile. After launching the Hubble telescope in 1990, astronomers discovered that it was near-sighted due to a defective mirror. Fortunately, three years later astronauts managed to repair it, much to the delight of astronomers around the world.

WENDY FREEDMAN The Hubble space telescope for the first time let us get above the earth's atmosphere. It made an enormous difference. It was like putting on a pair of eyeglasses. Suddenly we could see the universe very clearly.

MICHAEL GUILLEN (VO) The space telescope has also turned out to be a fitting tribute to astronomer Edwin Hubble. Back in the 1920s, at Pasadena's Mount Wilson Observatory, Hubble first discovered something very surprising. All the galaxies in the universe are moving away from each other like pieces of shrapnel from some huge explosion.

WENDY FREEDMAN This is what's led to this idea of a Big Bang universe, that is, that the universe began in a state of infinitely high temperature and density and has expanded ever since.

MICHAEL GUILLEN (VO) For the past six decades, the Big Bang theory has been little more than an educated guess. But now, picking up where Hubble the man left off, Hubble the telescope has all but cinched it. For as far as its powerful glass eye can see, out to the farthest horizon of the visible universe, galaxies are, indeed, flying away from each other. With this space-based detector, astronomers have also seen what appears to be the Big Bang's after glow-a cold, faint light coming to us from all directions.

ALAN GUTH Because the astronomers have so well confirmed the basic picture of the Big Bang it now makes sense to look at it in more detail and try to explain how it got started.

MICHAEL GUILLEN (VO) In daring to speculate about the details of what happened at that mysterious first moment of creation, scientists have teamed up the science of the very large with the science of the very small.

ALAN GUTH The universe began as a quantum fluctuation, a quantum jump, starting from absolutely nothing. Absolutely nothing means a situation completely devoid of either space or time.

MICHAEL GUILLEN (VO) Suppose this glass of soda water corresponds to absolutely nothing. According to Guth, the cosmos suddenly popped into existence like a tiny bubble and began to expand. It wasn't so much a big bang as it was a very, very rapid swelling.

ALAN GUTH The expansion was driven by a peculiar kind of substance that many particle theories predict should exist which actually creates a gravitational repulsion.

MICHAEL GUILLEN (VO) That peculiar substance was so powerfully repulsive, Guth believes, it inflated the infant universe faster than the speed of light, shattered space as if it were made of glass and led ultimately to the multiplicity of subatomic particles we see today.
So what happened after those first momentous events? Well, after looking carefully at the cores of about three dozen galaxies, including our own Milky Way, astronomers are spotting evidence for something totally unexpected.

DOUGLAS RICHSTONE, UNIVERSITY OF MICHIGAN They all seem to have massive black holes in them.

MICHAEL GUILLEN (VO) A black hole's gravitational field is so powerful, so irresistible, nothing that enters its deadly sphere of influence, not even a light ray, can escape. That's why you can't see a black hole, though its super powerful gravity does make surrounding stars orbit faster than usual and surrounding gases heat up so much they glow.

DOUGLAS RICHSTONE You compute the gravitational mass, you examine that region in space and there doesn't appear to be anything there that's emitting light or reflecting light and so the inference is it's a black hole.

MICHAEL GUILLEN (VO) Even more surprising, if this new discovery is true, black holes could very well be important agents of creation. Back when the universe was less than a billion years old, matter started clumping together. Some of those clumps became so dense they formed black holes and that's how galaxies might have been born. As swirling pinwheels of matter being sucked into those early black holes, like water swirling down a drain, so many of them, in fact, they started bumping into each other. Astronomers now realize this is how galaxies grow. When they collide, they merge. The bigger one devours the smaller one, a kind of cosmic cannibalization you see in this picture of a bloated, elliptically shaped galaxy.

ETHAN SCHREIER, SPACE TELESCOPE SCIENCE INSTITUTE We think they were very common at the beginning of the universe. Probably the elliptical galaxy we see here was the product of one or more mergers in the past and this is another merger, a relatively small merger as things go, which happened fairly recently.

MICHAEL GUILLEN (VO) As galaxies started to grow and collide, look there in the blue haze. Stars began to flare up like so many thermonuclear bombs. And after that came the planets. Look at this extraordinary infrared picture of debris swirling around a newborn star and you can actually see a clean area around the center. There, astronomers think, is where the debris is being swept together to form a small, new planet.
(on camera) With our powerful new telescopes we're just now beginning to realize that planets are plentiful. In fact, given what we're discovering, it's very likely that there are billions, even trillions of them out there, a humbling revelation given the arrogance it once took to believe that we were the center of the universe. A stunning achievement given the cleverness it's taken to figure out that we're not.

FORREST SAWYER Actually, it seems we're not only not the center of the universe, we're only beginning to figure out how little we really do know. In a moment, strange new questions.

(Commercial Break)

FORREST SAWYER Now comes the really weird part. You figure the universe ought to make sense and maybe it does-just not yet. Michael Guillen continues.

MICHAEL GUILLEN (VO) In the past few months, right when they were celebrating their newest eye-opening achievements, astronomers were blindsided by the apparent discovery of something unnerving-a kind of destabilizing force field that could damage some of our most cherished scientific notions.

ROBERT KIRSHNER I especially didn't really want to believe that. I thought oh, no, you know. So many people have gone down that road. We don't want to be down there.

MICHAEL GUILLEN (VO) And that's not all. Astronomers have also discovered something embarrassing. The universe seems to be much younger than we expected, younger, even, than some of its stars.

WENDY FREEDMAN What's going on here? How can you have objects in the universe that are older than the universe itself?

MICHAEL GUILLEN (VO) And finally, astronomers have discovered something unbelievable-the heavens appear to be filled with some very strange kind of invisible matter.

VERA RUBIN I think the stunned part comes from realizing the universe might be very different from what you thought it was.

MICHAEL GUILLEN (VO) Although there have been slight variations in the Big Bang theory, the overall big picture has always been pretty much the same, namely, ever since the universe began to expand, the force of gravity has been working against it, causing the universe to slow down like brakes on a car. Since the 1930s, that simple concept has been considered a basic truth.

ROBERT KIRSHNER The thing that everybody in their heart thought was right may turn out not to be true, that is, the evidence looks pretty good now that the universe hasn't been slowing down as much as you'd predict.

MICHAEL GUILLEN (VO) Astronomer Robert Kirshner came to that jarring realization while looking at super novae-exploding stars so bright they can be seen from clear across the universe 100 billion trillion miles away.

ROBERT KIRSHNER The super novae looked dimmer than you'd expect and that corresponds to bigger distances, that corresponds to a universe that's actually been speeding up, an accelerating universe.

MICHAEL GUILLEN (on camera) Suppose you are the astronomer and I'm a super nova. As the universe expands, I move away from you and get dimmer and dimmer. Simple. But the new discovery seems to show that I am moving away faster, getting dimmer faster than the Big Bang theory predicts. It's as if I'm being repelled from you by some powerful anti-gravitational force.

ALAN GUTH Calling it anti-gravity is, upsets a few physicists because it sounds like science fiction, but it is, in fact, what it is. It really is a gravitational repulsion which causes the universe to expand faster and faster.

WENDY FREEDMAN And if this idea is confirmed, it really will revolutionize many of our ideas, current understanding of physics and the evolution of the universe.

MICHAEL GUILLEN (VO) It could mean, for example, that the universe will expand forever, slowly pulling everything apart, unraveling every living thing, even the atoms, until the very last star is snuffed out.

ROBERT KIRSHNER Eventually, all the elaborate chemical elements like carbon and calcium and iron, the things we're made of, might actually disintegrate if you wait long enough. Then it would take you to a dark, cold, lonely universe.

MICHAEL GUILLEN (VO) The question of just how fast the universe is expanding is especially important to astronomer Wendy Freedman. She uses that information to calculate the age of the universe.

WENDY FREEDMAN In a sense it's like a movie, you can run it backwards and we can from that measurement of the expansion rate now deduce how long the universe must have been expanding and therefore its age.

MICHAEL GUILLEN (VO) So, how old is the universe? Well, if you take the positions and speeds of all the objects we can see today using our best telescopes and project them backwards using our best computers, then ...

WENDY FREEDMAN The measurements that I and my colleagues have made with the Hubble space telescope are indicating an age somehow in the range of nine to 12 billion years.

MICHAEL GUILLEN (VO) That's pretty old but it turns out some of the stars we've dated appear to be even older, leaving astronomers scratching their heads and wondering what's going on.

WENDY FREEDMAN It would be like my daughter coming to me and telling me that she's older than I am. It's just not a natural phenomena. Parents precede their children and the universe preceded the objects in the universe. So there's a paradox.

FORREST SAWYER We thought we'd save one of the most astounding revelations for last. It's just ahead.

(Commercial Break)

FORREST SAWYER We really do know more about the universe than we ever have. But how much more is that? Once more, Michael Guillen.

VERA RUBIN Every time we get a surprise, it means we've learned something we didn't know about and I think that's great. That's the way you should do science.

MICHAEL GUILLEN (VO) Thirty-three years ago, Vera Rubin started studying spiral shaped galaxies and ended up coming face to face with a strange kind of invisible matter.

VERA RUBIN I really set out just to find out how spirals orbited, why they came in different kinds and I thought maybe if I understood galaxies, I would understand other things.

MICHAEL GUILLEN (VO) And she was right. One day while peering at those beautiful galaxies, she noticed they were whirling so fast that by all rights the stars within them should have been flying off like sparks from a Fourth of July pinwheel. What was holding them together and causing them to spin so fast in the first place?

VERA RUBIN It's clear from the motions of stars in galaxies that the stars are being accelerated by an enormous amount of matter that we can't see and hence the idea of dark matter.

MICHAEL GUILLEN (VO) Unlike ordinary matter that emits or reflects light, dark matter is completely invisible, and yet judging from its effects throughout the heavens, this exotic, stealthlike matter is far more pervasive than common visible matter.

ROBERT KIRSHNER It might be that most of the universe is in a form of matter that's not the kind that we see or taste or feel or are made of, that there's this kind of ghostly background of particles that we're not sensitive to that constitute most of the universe.

MICHAEL GUILLEN Like 90 percent.

ROBERT KIRSHNER Like 90 percent.

MICHAEL GUILLEN (on camera) The implications of that are staggering because it means that within the universe we have been studying all along, for all these centuries we have been overlooking 90 percent of what's there. It's a demoralizing thought, but astronomers are confident that by early next century, their super sensitive telescopes will be able to resolve the mystery.

WENDY FREEDMAN It's fascinating that we can actually look at properties of the universe and try and understand something about how it came to be, how it's changing with time and perhaps what its fate will be and all that we're using is information that's coming to us from light, from distances.

ROBERT KIRSHNER We're just getting an early glimmer of what's going to turn out to be the real story of how the universe is constructed.

MICHAEL GUILLEN (VO) But despite astronomers' current optimism, the real story might take longer than they think. After all, the images that come to us from far away are distorted by a whole lot of dust in our own galaxy and solar system. So until our telescopes and satellites can rise above all that natural pollution, inevitably our understanding of the cosmos will remain cloudy and imperfect. As we strain to see the light, only one thing is clear-the more questions we answer, the more answers we end up questioning.

For Nightline, I'm Michael Guillen.

FORREST SAWYER When we come back, a few final words from ABC's Senior Science Correspondent Michael Guillen.

(Commercial Break)

FORREST SAWYER And joining us now from our Boston bureau is Michael Guillen.

And Michael, of all the very strange ideas that you were kicking around on tonight's report, the one that I really am having trouble with is the notion that the universe could somehow be younger than some of the stars that are in it. Now, how in the world do you do that?

MICHAEL GUILLEN It's pretty weird. My guess, Forrest, is that we're going to find out that, indeed, the universe is accelerating, as we've recently discovered, which means that the universe has been expanding slower in the past than it is now, which means it's taken longer to get where it is now than we are giving it credit for, which means that it is older than we are giving it credit for.

FORREST SAWYER Is it possible as they're sorting through all of these very complicated calculations that they've maybe put one number in the wrong place or something and they're kind of going down the wrong road because the calculations are wrong?

MICHAEL GUILLEN Yeah, it is possible. Most astronomers believe they're going to be able to salvage the Big Bang theory, that that's pretty solid. But the truth of it is we're always one discovery away either from confirming our theories or from demolishing our theories, Forrest, and that's what makes astronomy either so exciting and unnerving. And right now it's a 50-50 chance. It could go either way.

FORREST SAWYER I recall in the report here one of the scientists said five to 10 years from now we're going to know the answers to the big questions. Now, when we go back to him five to 10 years from now, do you think he's going to say see, I told you?

MICHAEL GUILLEN Gee, I've been hearing that kind of prediction for the last 20 years and people before me have been hearing that. Forrest, I think the basic problem in science is that every time we answer one question we raise a whole other bunch of questions. And so I think the odds are that we're probably going to take 5,000 to 10,000 more years before we answer all the questions.

FORREST SAWYER Now it's awfully interesting, the Hubble space telescope is really only looking in a certain band of light.

MICHAEL GUILLEN Yeah.

FORREST SAWYER It's light, but it's looking in a certain place. Coming down the road some more telescopes. What does that mean?

MICHAEL GUILLEN Well, you know, what's interesting is the universe reveals itself in different kinds of light. For example, the R-rated universe, what I call the very violent universe reveals itself in ultraviolet, gamma ray, X-rays. The G-rated universe, the kind of the ordinary universe that you and I see reveals itself in the ordinary visible, the optical range that the Hubble telescope is so good at looking at. And then the mild-mannered aspects of the universe, you know, the planetary birth, the birth of a star, the very gentle aspects of the universe are revealed in the infrared and in the microwave. And the beauty of it is that in the years to come, NASA's already lining up telescopes so they're going to be able to see the universe in all those lights. So the first time, in a sense, we'll be able to see the universe in its full Technicolor glory and that's very, very exciting.

FORREST SAWYER Just a few seconds left, Michael, give us a sense, the magnitude of this revolution in thinking. It seems staggering.

MICHAEL GUILLEN I remember a professor I had at Cornell in cosmology and he hung his head and he said, you know, I just don't think we're ever going to be able to answer all the questions about the universe. We don't have the wherewithal. But now I think we do. He can hold his head high. These new telescopes are going to be able to open our eyes, see where the universe came from, where it's going and where we fit in this glorious cosmos of ours, and that's very exciting.

FORREST SAWYER It's remarkable. Senior Science Correspondent Michael Guillen, thanks for giving us a glimpse tonight.

MICHAEL GUILLEN You bet, Forrest.

FORREST SAWYER That is our report for tonight. For the latest overnight developments, watch Good Morning America tomorrow. I'm Forrest Sawyer in Washington. For all of us here at ABC News, good night.

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