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  • Hawking: THE FARTHER WE PROBE INTO THE UNIVERSE,

  • THE MORE REMARKABLE ARE THE DISCOVERIES WE MAKE.

  • MUCH OF MY WORK HAS BEEN CONCERNED

  • WITH THE MYSTERIES OF BLACK HOLES.

  • MANY PEOPLE DISMISS BLACK HOLES

  • AS JUST AN ARTIFACT OF THE THEORY,

  • WHICH WOULDN'T EXIST IN THE REAL WORLD.

  • BUT THEN OBSERVERS BEGAN TO FIND THINGS IN THE SKY

  • WHICH WERE JUST AS PECULIAR.

  • Narrator: IN THE END, SCIENTISTS WOULD FIND

  • SOME VERY PECULIAR THINGS --

  • IMPOSSIBLY BRIGHT OBJECTS BLAZING FROM THE DISTANT PAST,

  • AND FORCES OF IMPENETRABLE DARKNESS.

  • THE FIRST THING THEY FOUND WAS SIGNALS,

  • RADIO WAVES FROM SPACE.

  • ASTRONOMERS TUNED IN IN SEARCH OF ALIENS.

  • Man: WELL, MY NAME IS SETH SHOSTAK,

  • AND I'M A AN ASTRONOMER AT THE SETI INSTITUTE

  • HERE IN LOVELY MOUNTAIN VIEW, CALIFORNIA.

  • THE ACRONYM "SETI" STANDS FOR

  • SEARCH FOR EXTRA-TERRESTRIAL INTELLIGENCE.

  • NOW, THAT "I" ON THE END

  • MEANS WE'RE NOT LOOKING FOR EXTRATERRESTRIAL LIFE,

  • BUT WE'RE LOOKING FOR INTELLIGENT LIFE.

  • THAT MEANS THEY CAN HOLD UP THEIR SIDE OF THE CONVERSATION,

  • IF YOU WILL.

  • AFTER THE SECOND WORLD WAR,

  • RADIO ASTRONOMY REALLY GOT GOING.

  • AND IN THE LATE '50s,

  • THEY STARTED BUILDING LARGE RADIO TELESCOPES,

  • LIKE THE ONE WE'RE SITTING UNDERNEATH.

  • COULD THIS TECHNOLOGY

  • ACTUALLY BE USED TO SEND MESSAGES, AS IT WERE,

  • BETWEEN THE STARS?

  • IN 1959, 1960, THE FIRST EXPERIMENTS WERE MADE

  • USING THIS KIND OF TECHNOLOGY -- A BIG RADIO TELESCOPE --

  • TO TRY AND EAVESDROP ON ANY CIVILIZATIONS

  • THAT MIGHT BE NEARBY.

  • Narrator: NO ALIENS FOUND, GRANTED,

  • BUT THERE WAS NO MISTAKING THE SIGNALS.

  • Shostak: SUDDENLY, YOU WERE GETTING

  • THESE CLEAR RADIO VIEWS, SO YOU KNEW THAT

  • IN THAT DIRECTION

  • THERE'S A VERY STRONG SOURCE OF RADIO WAVES.

  • YOU WOULD TELL YOUR FRIEND THE OPTICAL ASTRONOMER,

  • AND THEY WOULD GO USE A BIG TELESCOPE,

  • LIKE THE PALOMAR 200-INCH TELESCOPE,

  • OR SOMETHING SIMILAR,

  • AND THEY WOULD POINT IT IN THAT DIRECTION.

  • Narrator: WHERE THE UNIVERSE EMITTED A RADIO SIGNAL,

  • OPTICAL ASTRONOMERS NOW TRAINED THEIR GAZE.

  • WHAT THEY SAW DEFIED EXPLANATION.

  • BUT AT FIRST, ITS SIGNIFICANCE ELUDED THEM.

  • Man: PEOPLE SAW THAT THEY WERE UNUSUAL OBJECTS.

  • FOR EXAMPLE, A GALAXY THAT HAD A PECULIAR BLOB WITHIN IT

  • IN SOME CASES WAS FOUND TO EMIT RADIO WAVES.

  • WHEREAS A NORMAL-LOOKING, BORING-LOOKING GALAXY DID NOT.

  • OR, FOR EXAMPLE,

  • A CLOUD OF GAS THAT HAD

  • ALL SORTS OF LITTLE STRIATIONS IN IT,

  • AND LOOKED AS THOUGH IT MIGHT BE EXPLODING --

  • THOSE WERE PRECISELY THE OBJECTS

  • THAT SEEMED TO EMIT RADIO WAVES.

  • WHEREAS MORE NORMAL, QUIESCENT CLOUDS OF GAS DID NOT.

  • Narrator: GRADUALLY, THE STRANGE EVIDENCE MOUNTED.

  • WHEN OBSERVERS TURNED THEIR TELESCOPES

  • ON THE SOURCE OF PARTICULARLY STRONG RADIO SIGNALS,

  • THEY EXPECTED TO SEE COSMOLOGICAL CATASTROPHES.

  • INSTEAD, THEY WERE LEFT WITH COSMIC QUESTIONS.

  • Filippenko: IN THE EARLY 1960s,

  • OPTICAL ASTRONOMERS TOOK PHOTOGRAPHS

  • OF CTAIN POSITIONS IN THE SKY

  • FROM WHICH RADIO WAVES SEEMED TO BE COMING,

  • AND THEY JUST SAW NOTHING UNUSUAL.

  • THERE WAS JUST THE USUAL SMATTERING OF STARS,

  • AND THERE WAS NO OBVIOUSLY EXPLODING STAR,

  • NO TURBULENT CLOUD OF GAS, NOTHING SEEMINGLY UNUSUAL --

  • JUST NORMAL STARS.

  • AND THIS PERPLEXED THE ASTRONOMERS.

  • Narrator: TAKE THE CASE OF 3C273,

  • A STAR OF NO PARTICULAR DISTINCTION.

  • IT HARDLY SEEMED WORTH NOTICE,

  • THAT IS, UNTIL OBSERVERS BEGAN TO LOOK A LITTLE CLOSER.

  • Filippenko: 3C273 IN THE CONSTELLATION VIRGO

  • LOOKED JUST LIKE A STAR,

  • YET WE KNOW THAT ORDINARY STARS DON'T EMIT RADIO WAVES,

  • AND SO THIS WAS HIGHLY, HIGHLY UNUSUAL.

  • Narrator: USING A TECHNIQUE CALLED SPECTROSCOPY,

  • ASTRONOMERS STUDIED THE LIGHT

  • EMITTED BY 3C273.

  • WHEN YOU TAKE A SPECTRUM OF AN ORDINARY STAR,

  • THAT IS WHEN YOU PASS THE LIGHT THROUGH A PRISM

  • AND BREAK IT UP INTO A RAINBOW,

  • YOU CAN SEE SMALL DIPS, SMALL WIGGLES IN THE SPECTRUM.

  • AND THOSE ARE THE WIGGLES THAT ARE PRODUCED BY ATOMS,

  • BY GASES IN THE ATMOSPHERE OF THOSE STARS

  • THAT ARE ABSORBING SOME OF THE LIGHT.

  • AND BY IDENTIFYING THE PATTERN OF THESE LINES,

  • THESE LITTLE WIGGLES THAT APPEAR IN A STAR,

  • YOU CAN DEDUCE WHETHER THE ATMOSPHERE OF THE STAR

  • HAS HYDROGEN OR HELIUM AND OXYGEN --

  • THINGS LIKE THAT.

  • BUT IF THAT PATTERN IS SHIFTED TOWARD REDDER COLORS,

  • THEN YOU DEDUCE NOT ONLY THAT THE STAR HAS HYDROGEN

  • OR OTHER COMMON ELEMENTS,

  • BUT ALSO THAT THE STAR IS MOVING AWAY FROM YOU.

  • Hawking: 34 YEARS EARLIER,

  • THE AMERICAN ASTRONOMER, EDWIN HUBBLE,

  • HAD USED SPECTROSCOPY TO DISCOVER THAT

  • THE UNIVERSE IS EXPANDING.

  • DISTANT GALAXIES ARE MOVING AWAY FROM US.

  • THE SPECTRUM OF 3C273 WAS ABOUT TO TELL US EVEN MORE.

  • Filippenko: THE SPECTRUM OF 3C273

  • DIDN'T FIT ANY PATTERNS OF NORMAL GASES

  • THAT HAVE BEEN OBSERVED IN NORMAL STARS.

  • AND SO THIS REALLY BEFUDDLED ASTRONOMERS.

  • NOT ONLY WAS THE OBJECT EMITTING RADIO WAVES PROFUSELY,

  • BUT IT HAD THIS REALLY STRANGE SPECTRUM

  • THAT COULDN'T BE MATCHED WITH ANY KNOWN TYPE OF GAS.

  • Narrator: A STAR'S SPECTRUM IS ITS SIGNATURE,

  • AND THIS ONE WAS AN ABERRATION.

  • IT WAS ENOUGH TO LEAVE MANY ASTRONOMERS CONFOUNDED.

  • BUT FOR ONE, 3C273 WAS A REVELATION.

  • HE WAS CONVINCED SPECTROSCOPY COULDN'T LIE.

  • Filippenko: MARTIN SCHMIDT AT CALTECH.

  • NOTICED THAT TWO OF THE WIGGLES

  • HAD THE SAME SPACING BETWEEN THE COLORS

  • AS HYDROGEN DOES, BUT BOTH OF THE LINES

  • WERE SHIFTED WAY OVER TOWARD REDDER PARTS OF THE SPECTRUM

  • THAN NORMAL HYDROGEN GAS IS.

  • AND IF HE BELIEVED THAT THAT IDENTIFICATION WAS CORRECT,

  • THEN THE CONCLUSION WAS THAT THE SHIFT IS A FULL 16%.

  • YET A SHIFT OF 16% MEANT THAT THIS OBJECT

  • WAS MOVING AWAY FROM US ENORMOUSLY FAST, AND HAD TO BE

  • ONE OR TWO BILLION LIGHT YEARS AWAY.

  • SO, NO WAY COULD IT BE A NORMAL STAR

  • OR EVEN A PECULIAR MAGNETIC STAR IN OUR OWN GALAXY.

  • IT HAD TO BE SOME SORT OF A STRANGE OBJECT

  • THAT LOOKS STELLAR OR QUASI-STELLAR

  • SIMPLY BECAUSE IT'S SO, SO FAR AWAY,

  • AND YET IT'S ENORMOUSLY BRIGHT.

  • SO THIS REALLY CAUGHT PEOPLE BY SURPRISE,

  • AND A FEW PEOPLE, I THINK, HAD A HARD TIME BELIEVING

  • THAT ANYTHING SO RELATIVELY BRIGHT

  • COULD BE SO FAR AWAY.

  • ASTRONOMERS DECIDED TO CALL THESE OBJECTS,

  • THESE RADIO-STARS,

  • QUASI-STELLAR RADIO SOURCES.

  • THEY WERE CLEARLY RADIO SOURCES --

  • THEY WERE DISCOVERED WITH RADIO TELESCOPES --

  • AND THEY LOOKED STAR-LIKE,

  • AND HENCE THE STELLAR ASPECT OF THE TERM.

  • SO "QUASI-STELLAR RADIO SOURCES" GOT CONTRACTED TO "QUASARS."

  • MARTIN SCHMIDT CONCLUDED THAT IT MUST BE, INTRINSICALLY,

  • AN EXTREMELY POWERFUL SOURCE --

  • AN EXCEEDINGLY BRIGHT OBJECT INTRINSICALLY --

  • BECAUSE TO APPEAR AS BRIGHT AS IT DOES IN THE SKY,

  • YET BE SO FAR AWAY,

  • IT HAS TO PUT OUT A TREMENDOUS AMOUNT OF ENERGY PER SECOND --

  • MUCH, MUCH MORE THAN OUR SUN --

  • IN FACT, 100 TO 1,000 TIMES MORE

  • THAN OUR ENTIRE MILKY WAY GALAXY OF STARS.

  • AND THIS WAS THE REAL KICKER.

  • Hawking: WHEN THE MYSTERIOUS QUASARS WERE DISCOVERED,

  • I WAS JUST BEGINNING MY POST-GRADUATE RESEARCH.

  • MY WORK WAS TO LEAD ME TO STUDY THINGS

  • EVEN MORE MYSTERIOUS --

  • BLACK HOLES.

  • I WAS DEALING WITH EINSTEIN'S GENERAL THEORY OF RELATIVITY,

  • AND THIS SEEMED, TO SOME PHYSICISTS,

  • A PROMISING PLACE TO LOOK

  • FOR AN EXPLANATION OF THE QUASARS.

  • ASTRONOMERS AND ASTROPHYSICISTS WANTED AN EXPLANATION

  • FOR HOW THESE STRANGE OBJECTS

  • COULD BEHAVE IN THIS EXTRAORDINARY WAY --

  • HOW THEY COULD PRODUCE SO MUCH ENERGY,

  • AND YET BE SO SMALL.

  • AND SO THEY TURNED TO THE GENERAL RELATIVISTS,

  • AND ASKED THEM,

  • "WELL, DO YOU HAVE ANY MODELS FOR OBJECTS

  • "THAT COULD LOOK LIKE THIS,

  • THAT COULD BEHAVE IN THIS WAY AT ALL?"

  • AND THE RELATIVISTS SAID,

  • "WELL, THERE IS THIS ISSUE OF GRAVITATIONAL COLLAPSE,

  • AND MAYBE THIS IS WHAT YOU'RE LOOKING FOR."

  • Narrator: GRAVITY IS THE DOMINANT FORCE

  • IN THE UNIVERSE.

  • THIS TENET OF EINSTEIN'S WAS IRREFUTABLE.

  • BUT THERE WAS NO SUCH CONSENSUS ABOUT WHAT WOULD HAPPEN

  • UNDER VIOLENT CONDITIONS, LIKE THE DEATH OF A LARGE STAR.

  • EINSTEIN WONDERED, COULD ITS GRAVITATIONAL COLLAPSE

  • CRUSH ITS VAST QUANTITIES OF MATTER

  • INTO THE TINIEST OF POINTS?

  • Dowker: IN 1939, TWO PAPERS APPEARED.

  • ONE WAS BY EINSTEIN HIMSELF,

  • AND ONE WAS BY THE AMERICAN PHYSICIST,

  • ROBERT OPPENHEIMER, AND HIS CO-WORKER, SNYDER.

  • THEY DISCUSSED WHAT WOULD HAPPEN

  • WHEN A LARGE AMOUNT OF MATTER

  • WAS CONCENTRATED IN A SMALL REGION.

  • Narrator: EINSTEIN REJECTED

  • THE PROSPECT OF INFINITE COLLAPSE.

  • BUT OPPENHEIMER AND SNYDER'S CALCULATIONS

  • MADE THE CONCEPTUAL LEAP.

  • Dowker: USING THE RULES OF GENERAL RELATIVITY,

  • THEY PREDICTED THAT THAT MASSIVE OBJECT

  • WOULD UNDERGO CATASTROPHIC GRAVITATIONAL COLLAPSE

  • AND WOULD REACH A CRITICAL RADIUS

  • AT WHICH IT SEEMINGLY CUTS ITSELF OFF

  • FROM THE REST OF THE UNIVERSE.

  • Narrator: FOR MANY, THE IDEA OF A STAR

  • DESCENDING INTO SUCH AN ABYSS WAS UNTHINKABLE --

  • ALL THE MORE SO WHEN THE VIEW WAS SHARED

  • BY THE GREATEST LIVING SCIENTIST.

  • Dowker: EINSTEIN WAS CONVINCED

  • THAT YOU COULD NEVER GET TO THIS CRITICAL RADIUS,

  • THAT THIS CRITICAL RADIUS WAS AN IMPOSSIBILITY IN NATURE.

  • Narrator: THE CONTROVERSY WAS SHORT-LIVED FOR NOW.

  • WITH THE SECOND WORLD WAR,

  • OPPENHEIMER'S TALENTS WERE NEEDED ELSEWHERE,

  • DEVELOPING THE ATOMIC BOMB.

  • HIS EARLIER WORK LANGUISHED, DISMISSED BY PEERS

  • AS A RADICAL DEPARTURE FROM EINSTEIN.

  • BUT OPPENHEIMER HAD CONVINCED ONE COLLEAGUE,

  • JOHN WHEELER.

  • STICK UP FOR SOMETHING.

  • AND I THINK THAT'S A WONDERFUL WAY OF SAYING

  • WHAT SCIENCE IS ALL ABOUT.

  • STICK UP FOR SOMETHING.

  • Man: I'M DANIEL HOLZ, I'M A GRADUATE STUDENT

  • AT THE UNIVERSITY OF CHICAGO,

  • AND I'M GOING TO SEE JOHN WHEELER,

  • WHO WAS MY UNDERGRADUATE ADVISER HERE AT PRINCETON.

  • Narrator: FOR HOLZ,

  • THESE PERIODIC VISITS WITH HIS MENTOR ARE A PRIVILEGE.

  • AT AGE 85, JOHN WHEELER IS STILL A LUMINARY

  • OF 20th CENTURY SCIENCE.

  • Holz: HE'S CERTAINLY ONE OF THE GREATEST PHYSICISTS ALIVE,

  • AND HE'S CONTRIBUTED IN IMPORTANT WAYS

  • IN MANY DIFFERENT ASPECTS OF PHYSICS.

  • HE'S HAD FRESH IDEAS

  • THAT HAVE PUSHED THE VERY EDGES OF OUR KNOWLEDGE.

  • HE LOVES TO JUST SINK HIS TEETH INTO PROBLEMS.

  • PART OF HIS APPROACH IN PHYSICS IS,

  • FIND THE BIGGEST, MOST CONFUSING THING HE CAN,

  • AND THEN GO AT IT FULL STEAM AND TRY TO MAKE SENSE OF IT.

  • Narrator: WHEELER WAS WITNESS TO A REMARKABLE CHAPTER

  • IN THE ANNALS OF PHYSICS.

  • HE WORKED WITH OPPENHEIMER ON THE ATOMIC BOMB.

  • BUT BEFORE THAT,

  • WHEN WHEELER ARRIVED AT PRINCETON

  • IN THE 1940s,

  • EINSTEIN WAS THE MOST EMINENT MEMBER OF THE FACULTY.

  • IN 1963, THE CONTROVERSY ABOUT COLLAPSING STARS

  • WAS REKINDLED BY THE DISCOVERY OF QUASARS.

  • WHEELER HAD A DIFFICULT CHOICE BETWEEN TWO CONVICTIONS

  • AND TWO CHERISHED COLLEAGUES.

  • THOUGH HE DIFFERED WITH EINSTEIN,

  • HE RECALLS HIM FONDLY.

  • Wheeler: HE WAS KIND ENOUGH TO INVITE ME