THE NIGHT SKY IS THE GREATEST SHOW AROUND.

IT PLAYS WEEK AFTER WEEK.

EVEN ON SUNDAYS, ASSUMING THE WEATHER HOLDS.

PART OF ITS POWER IS ITS INFINITE MYSTERY.

NO ONE KNOWS WHERE STARS COME FROM OR WHY THEY SHINE.

FEW BELIEVE WE WILL EVER UNDERSTAND

WHAT THE UNIVERSE IS MADE OF--

WHAT THE TRUE NATURE OF MATTER REALLY IS.

BUT THEN, WITHIN A FEW YEARS, ALL HELL BREAKS LOOSE.

THERE ARE REVOLUTIONS IN ASTRONOMY AND PHYSICS

AND LONG-CHERISHED IDEAS ARE SHATTERED

ABOUT THE NATURE OF THE UNIVERSE AND SPACE AND TIME

AND EVEN REALITY ITSELF.

THE ONLY THING THAT REMAINS THE SAME

IS THE GLORY OF THE VIEW.

Osgood: FROM THE MOMENT THE TELESCOPE IS INVENTED

IT'S OUR WINDOW ON THE UNIVERSE.

IN THE 18th AND 19th CENTURIES

EVER LARGER AND MORE ELABORATE TELESCOPES

REVEAL EVER MORE STARS.

BY THE END OF THE 19th CENTURY

TELESCOPES ARE SO LARGE AND REVEAL SO MANY STARS

ASTRONOMERS ARE WORKING OVERTIME JUST TO CATALOGUE THEM.

THERE SEEMS LITTLE NEED TO BUILD EVEN BIGGER INSTRUMENTS

IF ALL THEY CAN DO IS FIND MORE STARS TO CATALOGUE.

BUT GEORGE ELLERY HALE DISAGREES.

HE'S PASSIONATELY CONVINCED

A BIG ENOUGH TELESCOPE WILL CHANGE ASTRONOMY

IN WAYS IT'S IMPOSSIBLE TO ANTICIPATE

AND HE'S DETERMINED TO MAKE THAT HAPPEN.

THAT PASSION BRINGS HIM TO MOUNT WILSON IN SOUTHERN CALIFORNIA

E AIR IS ALMOST ALWAYS FREE OF TURBULENCE AND CLOUDS.

IT'S THE PERFECT SPOT FOR AN OBSERVATORY.

WITH FUNDS FROM THE LIKES

OF STEEL TYCOON AND PHILANTHROPIST ANDREW CARNEGIE

HALE SETS OUT IN 1908 TO BUILD ON MOUNT WILSON

THE WORLD'S LARGEST TELESCOPE.

THE INSTRUMENT HE ENVISIONS WILL BE ALMOST TWICE THE SIZE

OF ANY THEN IN USE.

IT WILL COLLECT AND FOCUS LIGHT WITH A MIRROR 100 INCHES WIDE.

HALE'S ENTHUSIASM IS INFECTIOUS AND PERSUASIVE.

IT ALSO MASKS THE ENORMITY

OF THE TECHNOLOGICAL CHALLENGE HE'S UNDERTAKING.

Man: NOBODY IS POURING GLASS, MOLTEN GLASS

THE SIZE THAT IS GOING TO BE NECESSARY.

NOBODY IS CREATING THE KINDS OF BEAMS AND GIRDERS

AND THE SUPER GOING TO BE N ECESSARY.

THESE THINGS WEIGH HUNDREDS, THOUSANDS OF TONS.

YOU ALSO HAVE THE DIFFICULTY

THAT THEY'RE LOCATED ON MOUNTAINTOPS.

YOU HAVE TO BUILD THE ROADS.

YOU HAVE TO BUILD THE LIVING QUARTERS FOR THE ASTRONOMERS.

YOU HAVE TO HAVE MACHINE SHOPS ON SITE.

IT JUST GOES ON AND ON AND ON.

THESE ARE ALMOST KIND OF TECHNOLOGICAL KINGDOMS

IN THEIR OWN RIGHT

AND THEY'VE NEVER BEEN DESIGNED ON THIS SCALE BEFORE.

Osgood: THINGS SEEM TO GO WRONG FROM THE START.

THE MIRROR HAS TO BE THE LARGEST SOLID PIECE OF GLASS EVER MADE.

A FRENCH GLASSMAKER POURS

ENOUGH GREEN GLASS FOR 10,000 CHAMPAGNE BOTTLES

INTO A HUGE MOLD

AND THEN PACKS THE WHOLE THING IN MANURE TO SLOWLY COOL IT.

UNFORTUNATELY, IT COMES OUT FLAWED.

TWICE MORE THEY TRY

AND EACH TIME, THE GIANT DISKS CRACK AS THEY COOL.

LACKING THE MONEY TO TRY AGAIN

HALE ORDERS HIS OPTICIANS TO GRIND THE FIRST

IN THE HOPE ITS FLAWS AREN'T FATAL.

IT TAKES FOUR YEARS OF GRINDING AND POLISHING

TO FINISH THE MIRROR...

AND EVEN LONGER TO BUILD

T OF THE TELESCOPE AND ITS DOME.

HUNDREDS OF TONS OF STEEL AND CONCRETE

ARE HAULED UP THE MOUNTAIN ROAD

AT A CAUTIOUS TEN MILES PER HOUR.

EVEN AT THAT SPEED, ACCIDENTS HAPPEN.

THE STEEL SECTIONS OF THE TELESCOPE ITSELF

ARE BUILT AT AN EAST COAST SHIPYARD.

SOME ARE SO BIG THEY MUST BE SHIPPED BY BOAT TO CALIFORNIA.

WORLD WAR I HAS BROKEN OUT

AND GERMAN SUBMARINES ARE A CONSTANT THREAT.

LONG PRONE TO BOUTS OF DEPRESSION

HALE'S WORRIES ABOUT THE PROJECT BEGIN TO AFFECT HIS HEALTH.

THAT HE HAD BEEN VISITED

BY A COMPANION--

SORT OF DESCRIBED AS A LITTLE GREEN ELF

WHO MIGHT COME TO HIS BED OR SIT ON HIS SHOULDER

PERHAPS TO GIVE HIM ADVICE ABOUT HOW TO RUN HIS LIFE

AND HOW TO RAISE MONEY, WHO TO TALK TO.

IT'S HARD TO SAY.

THE ELF PERHAP WORK OUT SOME OF THIS STRESS.

Osgood: WHATEVER IT IS THAT CARRIES HALE THROUGH

ON NOVEMBER 2, 1917, THE 100-INCH TELESCOPE IS FINISHED.

ITS 100 TONS OF IRON AND STEEL MOVE

WITH THE PRECISION OF A FINE WATCH.

ITS 9,000-POUND MIRROR CAN DETECT A CANDLE

5,000 MILES AWAY.

WHAT HALE HAS BUILT IS ONE OF THE MARVELS OF THE 20th CENTURY.

IT WILL REIGN FOR DECADES AS THE BEST TELESCOPE IN THE WORLD

AND PROVE BEYOND DOUBT THE WORTH OF BIG TELESCOPES.

TO SPEND A NIGHT HERE

IS THE DREAM OF ASTRONOMERS THE WORLD OVER.

Christianson: YOU WOULD OPEN THE DOME-- A KIND OF ROLLING LIKE THUNDER.

YOU WERE ALONE ON THE MOUNTAIN WITH A TELESCOPE.

IT'S JUST YOU AND THE UNIVERSE OR YOU AND GOD, SO TO SPEAK.

Baliunas: YOU'D SIT AT THE PLATFORM AT THE TELESCOPE

GUIDING, MAKING VERY FINE ADJUSTMENTS

ON THIS MAGNIFICENT INSTRUMENT WITH A LITTLE HAND PADDLE

WITH YOUR EYE STARING DOWN ONTO THE ILLUMINATED CROSS HAIRS

AND WORK THERE EIGHT, TEN, 12 HOURS.

OFTENTIMES IT WAS EXTREMELY COLD.

IN WINTER THEY WORE HEAVY COATS.

SOMETIMES THEY WORE BEARSKIN OR SHEEPSKIN COATS.

YOU COULD LITERALLY HAVE YOUR TEARS FREEZE TO THE EYEPIECE

AND THEY WANTED HOT COFFEE BUT HALE WOULDN'T ALLOW IT.

HE THOUGHT IT WAS POISONOUS TO THE SYSTEM.

20 HOURS...

Osgood: COFFEE ISN'T ALL THAT HALE KEEPS OFF THE MOUNTAINTOP.

IN THE 1920s, I WOULD NOT HAVE BEEN ALLOWED TO WORK UP HERE.

IN FACT, I WOULDN'T HAVE BEEN WELCOME

EVEN AS A WIFE OR A VISITOR OF ANY OF THE SCIENTISTS.

HALE IN HIS DAYS AT YERKES

HAD FOUND THAT THE WIVES OF SOME OF THE ASTRONOMERS

BECAME A DISTRACTION TO THEIR MONASTIC SCHOLARLY STUDIES

AND SO THEY WERE ESSENTIALLY BANNED FROM THE MOUNTAINTOP.

Osgood: IRONICALLY, WITHOUT THE CONTRIBUTION MADE BY A WOMAN

THE FIRST GREAT DISCOVERY MADE WITH THE 100-INCH

MIGHT NOT HAVE BEEN POSSIBLE.

Man: THE CLOSEST A WOMAN COULD GET TO THE FIELD

WAS, AT THE TIME, AT THE HARVARD COLLEGE OBSERVATORY

WHERE MAJOR DATA-COLLECTING PROJECTS WERE IN PROGRESS.

HIRED ON TO HELP TO ANALYZE THE DATA WHERE MAJOR DATA-COLLECTING PROJECTS WERE IN PROGRESS.WERE

TO DO ALL THE MENIAL TASKS

THAT WERE BELOW THE DUTIES OF THE MEN.

Osgood: HENRIETTA LEAVITT IS ONE OF A DOZEN WOMEN

WHO STUDIED TENS OF THOUSANDS OF PHOTOGRAPHIC PLATES

TAKEN BY MEN AT DISTANT OBSERVATORIES.

LEAVITT'S TASK IS TO EXAMINE PLATES TAKENS

AND LOOK FOR STARS THAT VARY IN BRIGHTNESS.

SHE NOTICES A PATTERN IN ONE CLASS OF STARS CALLED "CEPHEIDS"

AND REALIZES THE TIME IT TAKES THEM

TO REACH THEIR MAXIMUM BRIGHTNESS

CAN BE USED TO DETERMINE HOW FAR AWAY THEY ARE.

IT'S A LANDMARK DISCOVERY.

BEFORE LEAVITT, ASTRONOMERS COULDN'T CALCULATE THE DISTANCE

TO ANY BUT THE CLOSEST STARS.

Tyson: WHAT HENRIETTA LEAVITT DID

WAS PROVIDE ONE OF THE FIRST AND STILL TO THIS DAY

ONE OF THE MOST FUNDAMENTAL YARDSTICKS IN THE UNIVERSE.

IT IS THE MEASURE BY WHICH ALL DISTANCES ARE DETERMINED.

WITHOUT THAT, WE'D BE CLUELESS.

Osgood: ALL THE ASTRONOMERS GEORGE HALE BRINGS TO MOUNT WILSON

WILL, AT SOME POINT IN THEIR CAREERS

MAKE USE OF LEAVITT'S CELESTIAL YARDSTICK.

BUT THERE'S ONE FOR WHOM IT WILL HAVE SPECIAL SIGNIFICANCE--

EDWIN HUBBLE.

A STAR ATHLETE IN COLLEGE

HUBBLE HAD WON A RHODES SCHOLARSHIP

AND STUDIED LAW AT OXFORD UNIVERSITY IN ENGLAND.

UPON RETURNING HOME, HOWEVER

HE DECIDES AGAINST BECOMING A LAWYER

AND HEADS OFF TO GRADUATE SCHOOL

TO TAKE SERIOUSLY A FASCINATION WITH THE STARS

THAT HE HAS FELT SINCE CHILDHOOD.

WHEN HUBBLE ARRIVES AT MOUNT WILSON IN 1919

HE'S A SMART BUT ARROGANT 29-YEAR-OLD

WHO HAS TAKEN PAINS TO ADOPT WHAT HE SEES

AS THE PROPER IMAGE OF AN ASTRONOMER.

Christianson: WHAT HE TRIES TO DO

IS TO CREATE THIS PORTRAIT OF HIMSELF

AS A KIND OF NATURAL-BORN PATRICIAN.

HE TRIES TO LOSE HIS MISSOURI ROOTS