Shape

NARRATOR: OUR WORLD IS BEAUTIFUL TO BEHOLD.

IT'S EVEN MORE BEAUTIFUL TO UNDERSTAND.

[NEIGHS] HA HA HA!

HA HA HA!

NARRATOR: FORCES OF UNIMAGINABLE POWER HAVE FORGED OUR PRECIOUS PLANET.

NARRATOR: THEY HAVE CREATED LANDSCAPES OF ENDLESS VARIETY AND WONDER.

THE FORCES OF NATURE ARE HIDDEN IN THE SHAPES THAT SURROUND US.

[ROOSTER CROWS] READ THE CODES WRITTEN INTO THE SHAPES OF NATURE... AND YOU WILL UNDERSTAND THE RULES THAT SHAPE EVERYTHING IN THE COSMOS.

[BICYCLE BELL RINGS] NARRATOR: CHILDREN PLAYING IN THE LATE AUTUMN SUN IN NORTHERN SPAIN.

NARRATOR: NOTHING COULD SEEM MORE NORMAL... NARRATOR: BUT THESE AREN'T ORDINARY CHILDREN.

BOY: AAH!

HA HA!

NARRATOR: CARLA AND HER FRIENDS ARE ABOUT TO PUT THEIR LIVES IN THE HANDS OF A FORCE SO STRONG IT CREATES THE SHAPE OF OUR PLANET.

[CROWD CHEERING] NARRATOR: THEY'RE GOING TO DO SOMETHING THAT WOULD TERRIFY MOST PARENTS.

[SPEAKING SPANISH] INTERPRETER: IT IS VERY EMOTIONAL, AND I AM VERY NERVOUS, NERVOUS FOR OUR CHILDREN, NERVOUS IN CASE THEY FALL AND GET HURT.

[MAN SPEAKING SPANISH] TRANSLATOR: IT'S OVERWHELMINGLY EMOTIONAL.

I GET GOOSEBUMPS.

EVEN BEFORE IT STARTS, I WELL UP AND CRY.

[CROWD CHANTING] NARRATOR: THESE CHILDREN ARE GOING INTO BATTLE WITH A FUNDAMENTAL FORCE OF NATURE-- THE FORCE OF GRAVITY.

TOWNS FROM ACROSS THE REGION COMPETE TO BUILD THE HIGHEST HUMAN TOWERS [SHOUTING IN SPANISH] NARRATOR: CARLA'S FAMILY ARE HERE WITH THEIR TEAM FROM VILAFRANCA.

NARRATOR: THE FAMILY PUT THEIR TRUST IN THE STRONGEST MEMBERS OF THE VILAFRANCA TEAM, PEOPLE LIKE DAVID MORRETT.

[MORRETT SPEAKING SPANISH] INTERPRETER: THE PRESSURE OF THE STAGE.

THE PLAZA IS CIRCULAR, AND THE SOUND IS VERY LOUD.

IT'S LIKE A PRESSURE COOKER.

FROM THE OUTSIDE, WE MAY LOOK LIKE A MASS OF PEOPLE... WHO PILE TOGETHER IN COMPLETE ANARCHY...

BUT IT'S NOT.

ALL THE STRUCTURES ARE SYMMETRICAL AT THE BASE.

THEN WE USE CONCENTRIC LINES TO CHANNEL THE FORCES TO THE CENTER.

NARRATOR: THESE HUMAN TOWERS GIVE US A GLIMPSE INTO WHAT IT TAKES TO DEFY GRAVITY.

AT THE BASE, EACH TEAM MEMBER IS POSITIONED SO THE BODIES SPREAD THE WEIGHT ABOVE THEM AS EVENLY AS POSSIBLE... TO DIFFUSE THE FORCE OF GRAVITY ACTING ON THEM.

THAT PRODUCES STRONG, SIMPLE SHAPES.

THE STRONGEST IS THE CIRCLE.

IT'S SYMMETRICAL, EQUAL IN ALL DIRECTIONS.

NO OTHER SHAPE DISTRIBUTES THE WEIGHT OF THE TOWER MORE EVENLY.

NO OTHER GIVES THE TOWER SUCH STRENGTH...

BUT, NO MATTER HOW STRONG THESE SHAPES ARE, GRAVITY IS UNFORGIVING.

THAT'S A WORRY IF IT'S YOUR CHILD CLIMBING TO THE VERY TOP.

[WOMAN SPEAKING SPANISH] INTERPRETER: WHEN CARLA AND MARIONA CLIMB THE TOWER, I WATCH THEIR EVERY MOVE.

SOME PARENTS DON'T LIKE IT, BUT I CAN'T NOT LOOK.

VILAFRANCA ARE ATTEMPTING TO BUILD THE HIGHEST, MOST COMPLEX TOWER OF THE DAY TO WIN THE COMPETITION... AND CARLA, BEING SO LIGHT, MUST CLIMB TO THE VERY TOP.

THE POWER OF EARTH'S GRAVITY MEANS THE WEIGHT BEARING DOWN ON DAVID IS HARD TO ENDURE.

IF ONE PERSON FALTERS, THE ENTIRE TOWER COULD BUCKLE, AND CARLA WILL PLUNGE TO THE BOTTOM.

[MORRETT SPEAKING SPANISH] INTERPRETER: IF THEY FALL, IT'S THE BIGGEST FAILURE.

THE CHILDREN ARE THE MOST FRAGILE.

YOU NEVER WANT THE MOST VULNERABLE TO FALL.

YOU WANT TO BUILD THE TOWER, BUT YOU DON'T WANT THEM TO GET HURT.

THAT PRESSURE IS ALWAYS THERE.

[CROWD CHEERING] NARRATOR: THEY'VE DONE IT.

[CHANTING "VILAFRANCA"] NARRATOR: THE CASTELLERS FROM VILAFRANCA ARE THE CHAMPIONS.

THE TEAM'S SKILL AND THE SHAPE OF THEIR TOWER HAS DEFIED GRAVITY... [CHANTING CONTINUES] NARRATOR: BUT LOOK AT THESE TOWERS IN A DIFFERENT WAY, AND THEY REVEAL HOW GRAVITY WORKS.

IMAGINE A COMPETITION LIKE THIS IN EVERY COUNTRY AROUND THE WORLD.

ALL THE TOWERS WOULD FALL IN THE SAME DIRECTION-- NOT JUST DOWN TO EARTH, BUT TOWARDS THE VERY CENTER OF OUR PLANET.

EARTH'S GRAVITY PULLS EVERYTHING DOWN TOWARDS ITS CENTER... NO MATTER WHERE YOU STAND... AND IT'S THIS PROPERTY THAT SHAPES OUR PLANET.

THE GRAVITY OF OUR PLANET PULLS EVERYTHING INWARDS...

INCLUDING THE ROCK FROM WHICH ITS MADE.

ROCK IS FORCED INWARDS IN EVERY DIRECTION... AND WHEN THAT HAPPENS, THERE'S ONLY ONE SHAPE A PLANET CAN BE-- A SPHERE.

OUR PLANET--A BEAUTIFUL SPHERE SUSPENDED IN SPACE.

EARTH IS ROUND BECAUSE IT HAS ENOUGH MASS, AND SO ENOUGH GRAVITY, TO PULL ITSELF INTO SHAPE.

IT'S THE SAME FOR THE MOON... AND ALL THE PLANETS OF THE SOLAR SYSTEM.

IT'S WHY OUR SUN AND STARS THROUGHOUT THE UNIVERSE ARE SPHERES.

GRAVITY IS A UNIVERSAL FORCE OF NATURE...

BUT IT'S NOT THE ONLY ONE.

THERE'S ANOTHER FORCE OF NATURE.

IT HOLDS ATOMS AND MOLECULES TOGETHER, CREATING THE SHAPES THAT SURROUND US.

IT'S CALLED THE ELECTROMAGNETIC FORCE.

MAN: IT'S SO MYSTICAL WHEN YOU LEAVE IN THE MORNING IN THE FOG.

YOU'RE JUST LOOKING AROUND, AND THEN YOU SEE THESE SHAPES WILL COME OUT OF THE FOG.

DIFFERENT MAN: THEY ARE BIG, BIG, HEAVY OBJECTS, FAR BIGGER THAN ANYTHING THAT WE'VE CREATED, FLOATING ON THE SEA.

NARRATOR: DOUG ALLAN IS AN UNDERWATER PHOTOGRAPHER.

HE WANTS TO TRACK DOWN A DANGEROUS AND UNPREDICTABLE SHAPE.

HE'S COME TO NEWFOUNDLAND BECAUSE THIS IS ICEBERG SEASON AND THIS PLACE IS CALLED ICEBERG ALLEY.

ICEBERGS FROM THE GREAT GLACIERS OF GREENLAND HAVE DRIFTED SOUTH TO THESE SHORES.

FROM HERE, OCEAN CURRENTS TAKE THEM OUT INTO THE ATLANTIC, AND THAT'S WHEN ICEBERGS CAN BECOME LETHAL.

EACH SUMMER, HUNDREDS OF ICEBERGS DRIFT INTO SHIPPING LANES AND OILFIELDS OFF THE COAST HERE, THREATENING A MULTIBILLION-DOLLAR INDUSTRY.

WE'VE GOT TO REMEMBER, IT WAS AN ICEBERG THAT SAILED PAST NEWFOUNDLAND WHICH ENDED UP SINKING THE TITANIC.

NARRATOR: ICEBERGS ARE SOME OF NATURE'S MOST SPECTACULAR NATURAL SCULPTURES.

THEY CAN BE MASSIVE, HUNDREDS OF THOUSANDS OF TONS OF SOLID ICE, BUT, DESPITE THEIR WEIGHT, ICEBERGS NEVER SINK TO THE BOTTOM OF THE OCEAN.

THEY FLOAT.

THIS STRANGE PROPERTY IS A DIRECT RESULT OF THE FORCE OF ELECTROMAGNETISM, THE FORCE OF NATURE THAT BINDS COUNTLESS BILLIONS OF MOLECULES OF WATER TOGETHER TO CREATE THESE BERGS.

ALLAN: WATER IS A POLAR MOLECULE.

IT HAS A POSITIVE END AND A NEGATIVE END, AND AT NORMAL TEMPERATURES, THE KINETIC ENERGY, THE ENERGY OF THE MOVEMENT OF THE MOLECULES, IS WAY, WAY STRONGER THAN THIS POLAR FORCE IS, BUT AS THE WATER COOLS DOWN AND THE MOLECULES MOVE MORE SLOWLY, THEY BEGIN TO AFFECT HOW THE MOLECULES LINE UP.

NARRATOR: WATER MOLECULES ARE ELECTRICALLY CHARGED, AND OPPOSITES ATTRACT.

THE POSITIVE HYDROGEN ATOMS OF ONE WATER MOLECULE BOND WITH THE NEGATIVE OXYGENS OF OTHERS, AND AS WATER FREEZES, THE MOLECULES ARRANGE INTO A LATTICE OF HEXAGONS, AND THAT MAKES THEM TAKE UP MORE SPACE.

ALLAN: ICE IS A--IS A REALLY STRUCTURED SUBSTANCE.

IT'S--IT'S ALMOST HOLLOW.

IT'S A LATTICE STRUCTURE, AND, AS SUCH, IT'S-- IT'S LESS DENSE THAN WATER, AND THE FACT THAT IT'S LESS DENSE MEANS THAT IT FLOATS.

NARRATOR: ALMOST ALL OTHER LIQUIDS BECOME MORE DENSE WHEN THEY FREEZE...

BUT WATER EXPANDS.

THE INCALCULABLE NUMBER OF HEXAGONS IN EACH ICEBERG MEANS A 100,000-TON BLOCK OF ICE CAN FREELY FLOAT IN THE SEA.

ALLAN: ICEBERGS STILL POSE A SIGNIFICANT HAZARD TO SHIPPING, NOT JUST LOCAL SHIPPING TO ST. JOHNS, BUT ALSO SHIPPING COMING ACROSS THE ATLANTIC.

[GULLS SQUAWKING] NARRATOR: EVER SINCE THE TRAGIC LOSS OF LIFE ON THE TITANIC, ICEBERGS HAVE BEEN INTENSELY MONITORED.

TODAY DOUG IS JOINING A TEAM OF SCIENTISTS WHO WANT TO PREDICT HOW ICEBERGS BEHAVE.

THE TEAM WANT TO GATHER DATA ON THE SHAPE OF AN ICEBERG, INFORMATION WHICH WILL HELP PREDICT ITS TRAJECTORY OUT TO SEA.

THE EXPEDITION IS LED BY NEIL RIGGS.

HE KNOWS FIRSTHAND HOW DANGEROUS FLOATING ICE CAN BE.

RIGGS: ICEBERG ICE REFLECTS RADAR 69 TIMES LESS EFFECTIVELY THAN A SHIP OF THE SAME CROSS-SECTIONAL AREA...

SO, YEAH, WE'VE GOT SOME KIND OF STILL ONES OVER HERE.

RIGGS: SO YOU COULD BE SAILING ALONG AND DOING VERY GOOD SEAMANSHIP, LOOKING AT YOUR RADAR, AND THERE'S THE THING ALL OF A SUDDEN, AND YOU'RE UPON IT, AND IT'S STILL A MASSIVE PIECE OF ICE RELATIVE TO YOUR SHIP, SO IT COULD MAKE A NICE, LITTLE HOLE.

NARRATOR: THE SCIENTISTS ARE USING SPECIALLY DESIGNED REMOTE SENSORS TO SCAN ICEBERGS FROM EVERY DIRECTION.

ALLAN: IT'S A COMPLICATED JIGSAW.

IT'S A LITTLE BIT-- YOU COULD THINK OF IT AS A CRIME SCENE WHERE YOU HAVE THE FORENSIC PEOPLE GO IN AND THEY PICK UP LITTLE BITS OF CLUES AND TOGETHER, YOU MAKE A BIGGER PICTURE.

NARRATOR: AERIAL MAPPING AND SONAR ROBOTS ARE STILL IN THEIR TEST PHASE, SO THERE'S NO SUBSTITUTE FOR FIRSTHAND OBSERVATION...

PARTICULARLY UNDERWATER, WHERE THE SHAPE OF THE ICEBERG BECOMES JUST A SHADOW.

MAN: IT'S HARD TO PIECE TOGETHER WHAT WE'RE SEEING ABOVE WATER WITH UNDERWATER WITHOUT-- WITHOUT YOUR IMAGERY, SO THAT'S WHAT THIS IS GOING TO BE REALLY HELPFUL FOR.

ALLAN: I'LL ACTUALLY GET A PICTURE OF WHAT THE THING ACTUALLY LOOKS LIKE SO THEY CAN, HOPEFULLY, TELL MORE ABOUT HOW ACCURATE THEIR SONAR PICTURE IS, COMPARED TO THE REAL THING.

IT'S QUITE EERIE, GOING DOWN THE SIDE OF THE ICEBERG.

YOU'RE GOING DOWN INTO THE DARKNESS, INTO THE BLUE, INTO THE GREEN... AND VERY OCCASIONALLY, THERE'LL BE THIS REALLY LOUD THUMP, JUST LIKE SOMEONE HAD HIT YOU WITH THE FLAT OF THEIR HAND IN THE CENTER OF YOUR CHEST.

NARRATOR: BEING THIS CLOSE GIVES DOUG AN UNRIVALLED VIEW OF THE SHAPE THAT'S HIDDEN BENEATH THE WAVES.

THANKS TO THE ELECTROMAGNETIC FORCE THAT HOLDS FROZEN WATER MOLECULES TOGETHER, ICE FLOATS, BUT ONLY JUST.

7/8 OF AN ICEBERG IS BENEATH THE SURFACE.

THE PART UNDERWATER IS CALLED THE KEEL.

IT CATCHES THE OCEAN'S CURRENTS... AND AFFECTS THE SPEED AND DIRECTION THE ICEBERG WILL TRAVEL.

UP THIS CLOSE, DOUG HAS DISCOVERED THE KEEL OF THE BERG IS RIDDLED WITH EVEN MORE COMPLICATED SHAPES.

ALLAN: SO WHILE I'M SWIMMING ALONG THE ICEBERG, I'M VERY AWARE OF THE DIMPLED SHAPES.

IT'S LIKE A GIANT GOLF BALL ON ONE SIDE OF ME, AND I'M JUST HOPING THAT ALL THESE SORT OF OBSERVATIONS FROM ME MYSELF AND THE FACT THAT I'M PUTTING THEM DOWN ON FILM, I'M HOPING THAT, THAT WILL BE USEFUL FOR THE SCIENTISTS.

HOW WAS THAT?

PHWAH!

"HOW WAS IT?"

IT WAS COLD, IT WAS A LITTLE BIT MURKY, AND I'LL TELL YOU ALL ABOUT IT WHEN I GET ON THE BOAT.

[LAUGHTER] NARRATOR: THE IRREGULAR AND HIDDEN SHAPE OF ICEBERG KEELS MEANS PREDICTING A BERG'S TRAJECTORY IS STILL AN IMMENSE CHALLENGE...

YET NO MATTER HOW COMPLICATED THEIR SHAPE, IT'S THE SIMPLE HEXAGON THAT MAKES AN ICEBERG FLOAT.

BILLIONS UPON BILLIONS OF THEM FORM WHENEVER AND WHEREVER WATER FREEZES ON EARTH.

ALL ICEBERGS STARTED THEIR LIFE AS TINY, DELICATE SNOWFLAKES... COME ON.

NARRATOR: EACH ONE SHAPED BY THE ELECTROMAGNETIC FORCE.

OH, THERE YOU GO.

WHOA!

NARRATOR: UP IN THE CLOUDS, WATER MOLECULES MOVE FAST AND ARE FLOWING FREE...

BUT WHEN IT'S COLD ENOUGH, THE MOLECULES SLOW DOWN.

ELECTROMAGNETISM TAKES OVER, AND A HEXAGON APPEARS.

THIS SIMPLE SHAPE BECOMES MORE INTRICATE AS EACH SNOWFLAKE FALLS.

CRYSTALS GROW FROM EACH CORNER.

EVERY SNOWFLAKE TAKES UP A UNIQUE SHAPE AS IT DESCENDS THROUGH THE CHAOS OF THE ATMOSPHERE.

EVERY SNOWFLAKE IS DIFFERENT, BUT THE BEAUTIFUL, 6-SIDED SYMMETRY IS AN ECHO OF THE WATER MOLECULES THAT MADE IT.

PERFECT, SYMMETRICAL SHAPES ARE THE EXCEPTION, NOT THE RULE, BECAUSE THE FORCES THAT SHAPE NATURE ARE IN A CONSTANT BATTLE FOR SUPREMACY.

GRAVITY CAUSES RIVERS TO FLOW.

THE CONSTANT RUSH OF WATER BREAKS ROCK APART...

ERODING AND CARVING SOME OF THE GREATEST LANDSCAPES ON OUR PLANET.

IN THE VAST SWEEP OF AFRICAN DESERTS, SAND DUNES ARE IN A STATE OF CONSTANT MOTION.

WIND BREAKS THE ELECTROMAGNETIC FRICTION THAT STICKS SAND GRAINS TOGETHER.

THE FORCE OF GRAVITY TAKES OVER, AND THEY TUMBLE DOWNHILL UNTIL THE TWO FORCES ARE BACK IN BALANCE AGAIN, AT LEAST FOR A MOMENT.

MOUNTAINS ARE THE GREATEST TESTAMENT TO THE BATTLE BETWEEN THE FORCES OF NATURE ON OUR PLANET.

MOST OF THE EARTH'S LARGEST MOUNTAINS PEAK AT 14,000 FEET.

BEYOND THAT, THE FORCE OF GRAVITY MAKES THEM TOO HEAVY.

THE MOLECULAR BONDS HOLDING EARTH'S CRUST TOGETHER CAN'T SUPPORT THEIR WEIGHT...

BUT IN THE HIMALAYAS, EVEREST AND ITS NEIGHBORS SIT ON PARTICULARLY STRONG FOUNDATIONS.

THEY CAN SUPPORT THE PULL OF GRAVITY BETTER.

THESE ARE THE HIGHEST MOUNTAINS ON OUR PLANET...

BUT THEY'RE NOT THE HIGHEST MOUNTAINS THAT CAN EXIST.

MARS IS SMALLER THAN EARTH.

CRUCIALLY, THAT MEANS IT HAS LESS GRAVITY, THE GREAT MOUNTAIN SLAYER.

ON MARS, WE CAN SEE THE HIGHEST MOUNTAIN IN THE SOLAR SYSTEM.

WITH ABOUT A THIRD LESS GRAVITY PULLING IT DOWN, OLYMPUS MONS IS NEARLY 3 TIMES HIGHER THAN EVEREST.

IT RISES UP OVER 80,000 FEET.

OUR BEAUTIFUL SPHERE HAS BEEN MADE ROUGH BY THE BATTLE BETWEEN THE FORCES OF NATURE.

EACH WRINKLE HAS CREATED A NEW LANDSCAPE... LANDSCAPES THAT ARE HOME TO LIFE... [BUZZING] [LAUGHING] NARRATOR: AND WITH LIFE COMES A RULE OF NATURE THAT CREATES MYRIAD SHAPES IN THE NATURAL WORLD-- EVOLUTION.

NEPAL IS HOME TO A MAGNIFICENT SHAPE...

CREATED BY LIFE ITSELF... A SHAPE THAT IS ESSENTIAL TO LIFE TO SURVIVE UP HERE.

[ROOSTER CROWS] NARRATOR: THESE MEN OF THE GURUNG PEOPLE ARE PREPARING TO SEEK IT OUT.

TRANSLATOR: LET HIM COME.

I'LL TEACH HIM.

IF HE CAN'T DO IT, I'LL KICK HIM.

NARRATOR: THEY'RE GOING ON AN EXPEDITION TO FIND ONE OF NATURE'S PERFECT SHAPES, SUPERBLY DESIGNED TO SAVE ENERGY.

THE MEN ARE HONEY HUNTERS, AND THEY'RE LEAVING THEIR VILLAGE TO FIND THESE-- [BUZZING] THE LARGEST HONEY BEES IN THE WORLD.

THE HIMALAYAN HONEY BEE BUILDS GIANT HIVES THAT CAN BE OVER 6 FEET ACROSS.

THE BEES WORK ENDLESSLY TO PROTECT THEM.

THIS MEXICAN WAVE IS MEANT TO SCARE OFF PREDATORS THAT APPROACH IT.

HIDDEN BENEATH THE PROTECTIVE LAYER OF FEROCIOUS BEES IS A DELICATE NETWORK OF EXQUISITELY ENGINEERED HEXAGONS.

THESE CAREFULLY BUILT CELLS WILL BE USED TO STORE HONEY, ESSENTIAL FOOD THAT WILL GET THE BEES THROUGH THE LEAN MONTHS...

BUT WHY HEXAGONS?

WHAT IS IT ABOUT HEXAGONS THIS TIME THAT MAKES THEM THE BEST SHAPE FOR HONEYCOMBS?

[CHANTING] NARRATOR: SOME SHAPES ARE PURELY DECORATIVE...

BUT THE HEXAGON IS USEFUL.

IT'S A SHAPE THAT TESSELLATES.

IT PACKS TOGETHER, LEAVING NO GAPS.

[CHANTING] NARRATOR: OTHER SHAPES DO THE SAME TRICK, LIKE TRIANGLES OR SQUARES...

BUT THE HONEYBEE ONLY USES THE HEXAGON.

THE HEXAGON IS DIFFERENT TO OTHER SHAPES THAT TESSELLATE.

IT'S THE SHAPE THAT ALLOWS THE BEES TO STORE THEIR HONEY MOST EFFICIENTLY.

THE BEES HAVE DISCOVERED THE HIDDEN PHYSICAL RULE THAT HELPS THEM SURVIVE THE COLD HIMALAYAN WINTERS... AND TWICE A YEAR, THE GURUNG VILLAGERS HEAD INTO THE MOUNTAINS TO EXPLOIT THE SECRET THE BEES HAVE DISCOVERED.

ON THIS TRIP, THE LEADER, MIN, IS TAKING HIS YOUNG NEPHEW HIRA ALONG FOR THE FIRST TIME.

TRANSLATOR: WE'VE SET OUT TO DO IT, SO WE HAVE TO DO IT.

DIFFERENT TRANSLATOR: IF WE SLIP, IT WILL BE DISASTROUS.

[SPEAKING FOREIGN LANGUAGE] THIS IS MY FIRST TIME... AND I'M NOT SURE HOW...

I AM SUPPOSED TO GET THE HONEY.

I FEEL FRIGHTENED, BUT I HAVE TO OVERCOME MY FEAR.

NARRATOR: IT'S NOT JUST A FEAR OF THE BEES.

IT'S WHERE THEY'VE BUILT THEIR HIVES THAT WORRIES HIRA-- [SPEAKING FOREIGN LANGUAGE] TRANSLATOR: HIRA, LOOK.

THERE ARE A LOT OF HONEYCOMBS HERE.

NARRATOR: HIGH ON THE FACE OF A VERTICAL CLIFF.

[BUZZING] BUILDING THESE ENORMOUS CONES IS HARD WORK.

IT TAKES ENERGY.

FOR EVERY OUNCE OF WAX, A BEE HAS TO CONSUME AT LEAST 6 OUNCES OF VALUABLE HONEY, BUT THE BEES HAVE LEARNED TO USE A RULE OF GEOMETRY.

OF ALL THE SHAPES THAT COULD BE USED FOR PACKING, THE HEXAGON IS THE MOST EFFICIENT.

IT'S THE SHAPE THAT NEEDS THE LEAST WAX TO BUILD, WHICH MEANS THE BEES USE UP LESS ENERGY MAKING IT AND MORE HONEY CAN BE PUT INTO STORAGE.

[SPEAKING FOREIGN LANGUAGE] TRANSLATOR: NEPHEW, DON'T BE AFRAID.

THE HONEYCOMBS ARE HERE, THERE, AND EVERYWHERE.

IF EVERY ONE HAS HONEY, THEN YOU CUT EVERY COMB.

NARRATOR: HIRA APPROACHES THE HIVES FROM ABOVE.

THERE'S A LOT RIDING ON THESE HOMEMADE ROPE LADDERS.

[SPEAKING FOREIGN LANGUAGE] TRANSLATOR: THE MOST DANGER IS WHEN YOU COME OVER THE CLIFF.

YOU FEEL LIKE IT'S GOING TO BE THE LAST DAY OF YOUR LIFE.

NARRATOR: FINALLY, MIN AND HIRA MAKE IT TO THE HONEYCOMBS.

THE HONEY HUNTERS ARE PRECARIOUSLY HANGING IN FRONT OF THE SWARM.

UNDER CONSTANT ATTACK, MIN GUIDES HIRA, KEEPING HIM FOCUSED ON THE TASK AHEAD.

HOLDING OUT THE LONG CUTTING TOOL MAKES THE BALANCING ACT EVEN HARDER.

THE HEXAGONAL CELLS OF THE CONES ARE PACKED FULL OF HONEY, SO MUCH HONEY THAT EACH PIECE OF HONEYCOMB CAN WEIGH AROUND 50 POUNDS.

ONE SLIP COULD MEAN ALL THIS EFFORT IS WASTED, BUT HIRA'S FIRST ATTEMPT AT HONEY HUNTING IS A SUCCESS.

[HIRA SPEAKING FOREIGN LANGUAGE] TRANSLATOR: IN THE BEGINNING, I WAS VERY AFRAID...

BUT IF YOU FIND YOUR INNER COURAGE AND FOCUS ON THE JOB, YOU'RE NOT AFRAID ANYMORE.

[MIN SPEAKING FOREIGN LANGUAGE] TRANSLATOR: IT WAS HIS FIRST TIME, AND HE DID A GREAT JOB.

HE GOT THE HANG OF IT QUICKLY AND DID A GOOD JOB.

[MIN SHOUTS] NARRATOR: SAFELY ON THE GROUND, THE HONEY HUNTERS CAN RETURN HOME WITH THEIR PRIZE.

IN CRAFTING THEIR HEXAGONAL CELLS, THE BEES ARE OBSERVING A RULE OF NATURE-- THE RULE OF EFFICIENCY, OF SAVING AND MINIMIZING ENERGY.

THE BEES NEED LESS WAX.

LESS ENERGY IS SPENT ON BUILDING THEIR HOME.

MORE HONEY CAN BE STORED.

[CLAMORING] NARRATOR: IT'S GOOD FOR THE GURUNG PEOPLE OF NEPAL AND THE BEES.

HEXAGONAL HONEY CONES ARE A MAGNIFICENT EXPRESSION OF EVOLUTION.

[ROOSTER CROWS] EVOLUTION SHAPES LIFE... AND IN THE WETLANDS OF FLORIDA, THERE'S A BIZARRE CREATURE THAT HAS ADAPTED ITS SHAPE TO SURVIVE.

THESE SHALLOW WATERS PROVIDE SHELTER AND PROTECTION FOR A VAST ARRAY OF MARINE LIFE...

BUT ONE CREATURE IS LIVING LIFE ON THE EDGE-- THE MANATEE.

FLORIDA IS AT THE NORTHERN LIMIT OF WHERE MANATEES LIVE.

ANY FURTHER NORTH WOULD BE PERISHINGLY COLD.

THEIR LIFESTYLE DOESN'T SEEM TO HELP.

THEY ARE HARDLY DYNAMIC, AVERAGE SPEED--WALKING PACE.

ALGAE EVEN GROWS ON THEM.

THEY'RE ALSO VEGETARIAN.

THEY CONSUME 10% OF THEIR BODY WEIGHT IN LEAVES AND SEA GRASS EVERY DAY.

FOR THIS WARM-BLOODED CREATURE, IT'S A STRUGGLE FOR SURVIVAL...

PARTICULARLY WITH TWO EXTRA MOUTHS TO FEED.

IT'S WINTER IN FLORIDA, MAKING THE MANATEES ESPECIALLY VULNERABLE.

IF IT GETS TOO COLD, THEY COULD DIE.

WILMA RUTH.

WHO ELSE WE GOT HERE?

AH, PADDY DOYLE AND BRUTUS.

NARRATOR: RESEARCHER WAYNE HARTLEY IS DOING HIS DAILY HEAD COUNT.

HARTLEY: IT'S A SPECIAL THING TO COME TO WORK.

YOU COME DOWN IN THE MORNING, AND IT'S QUIET.

STEAM'S COMING OFF THE WATER.

[EXHALES] HARTLEY: YOU CAN HEAR THE MANATEES OUT THERE BREATHING.

IT'S JUST, "WHOOSH"... AND THEY ARE SO PEACEFUL.

THEY ARE SO CALM.

NARRATOR: EACH WINTER, MANATEES SEEK REFUGE IN FLORIDA'S NATURAL HOT SPRINGS.

BIOLOGIST AMY TEAGUE IS HERE TO DO A HEALTH CHECK.

I'VE GOT 23.5 DEGREES CELSIUS.

23.5.

MM-HMM.

OK. NARRATOR: THE SPRINGS ARE A NATURAL HOT TUB, BUT SOME HAVE MADE IT HERE JUST IN TIME TEAGUE: HE IS SEVERELY COLD-STRESSED.

HARTLEY: WITH THE COLD-STRESS, THEY DON'T EAT.

THEIR IMMUNE SYSTEM SHUTS DOWN, NOT A GOOD THING.

TEAGUE: THEY'RE HERE TO KEEP THEMSELVES ALIVE IN THE WINTER.

THEY--THEY REALLY REQUIRE WARM WATER.

NARRATOR: FOR MANATEES, A WINTER IN FLORIDA IS LIKE BEING IN THE ARTIC.

ALTHOUGH THEY ARE LIVING ON THE EDGE OF EXISTENCE, THEIR BODY SHAPE HAS EVOLVED TO HELP THEM SURVIVE.

LOOKING AT THIS ANIMAL, YOU MIGHT THINK THAT HE'S QUITE FAT, BUT IN ACTUALITY, THEY HAVE A VERY THICK DERMIS LAYER WHICH IS THEIR SKIN, BUT THEY DON'T HAVE A VERY THICK FAT LAYER.

NARRATOR: IT MIGHT LOOK LIKE THESE ANIMALS KEEP WARM LIKE SEALS, USING BLUBBER, BUT THEY'RE NOT FAT.

THEY'RE JUST ROUND, AND ROUND IS THE SHAPE TO BE IF YOU'RE TRYING TO HOLD ON TO BODY WARMTH.

TEAGUE: THIS ROUND SHAPE HAS ACTUALLY COME TO THEIR BENEFIT IN THAT REDUCES THEIR SURFACE-AREA-TO-VOLUME RATIO, SO IT'S KIND OF LIKE US GETTING COLD AND--AND SORT OF HUDDLING INTO A BALL.

WELL, THEIR ROUNDNESS ACTS ESSENTIALLY IN THE SAME WAY TO HELP THEM CONSERVE THEIR HEAT.

NARRATOR: THEIR BULBOUS BODIES ARE ALSO HEATED FROM INSIDE.

THEY'RE FILLED WITH UP TO 130 FEET OF INTESTINES WHICH ACTS LIKE AN INTERNAL FURNACE AS THEY DIGEST THEIR FOOD.

SORRY.

THEIR BREATH STINKS.

HA HA HA!

HARTLEY: THAT'S GOOD.

TO ME, IT SMELLS LIKE THE INSIDE OF A HOT TRUCK TIRE.

HA HA HA!

NARRATOR: FLORIDA MANATEES HAVE EVOLVED IN THIS COLD ENVIRONMENT, AND THEIR SHAPE HAS ADAPTED TO COPE.

IN TERMS OF PURE PHYSICS, IT WOULD BE IDEAL FOR THE MANATEES TO BE SPHERES, THE SHAPE WITH THE LOWEST SURFACE-AREA-TO-VOLUME RATIO OF ALL...

BUT LIFE DOESN'T QUITE WORK LIKE THAT.

MANATEES HAVE SOME PRETTY ESSENTIAL NONSPHERICAL PARTS.

THEY SHARE AN ANCESTOR WITH ELEPHANTS.

THEIR FINS ARE BUILT LIKE LEGS.

THEY EVEN HELD ONTO FINGERNAILS THAT PROTECT THEIR SKIN SO THEY CAN WALK ON THE BOTTOM... AND THEY HAVE AN ELEGANT, PADDLE-SHAPED TAIL.

IT MEANS, ALTHOUGH THEY'RE NOT THE FASTEST ANIMAL, THEY CAN MOVE... AND KEEPING MOVING HAS BECOME AS IMPORTANT AS KEEPING WARM BECAUSE THE MANATEES ARE BEGINNING TO GATHER AT ANOTHER VERY UNLIKELY HOT SPOT.

AMY IS HEADING OFF TO FIND THEM.

THE MANATEES' NATURAL WARM-WATER HAVENS ARE FAST DISAPPEARING... AND THEIR HIGHLY SPECIALIZED BODIES AREN'T ADAPTING FAST ENOUGH.

WELL, AS THE HUMAN POPULATION GROWS, MORE DEMAND GOES ONTO RESOURCES THAT WE SHARE WITH THE MANATEES, AND--AND THAT'S THE SPRINGS.

MANATEES DEPEND ON THESE NATURAL SPRINGS FOR WARM-WATER HABITAT.

HOWEVER, HUMANS ALSO RELY ON THESE SPRINGS UM, FOR DRINKING WATER, FOR AGRICULTURE REASONS.

IT CONCERNS ME IN THAT, YOU KNOW, MAN-- MANATEES' WARM-WATER HABITAT AVAILABILITY IS--IS UNCERTAIN.

IT--IT'S REALLY SAD, YOU KNOW.

I--I DON'T WANT TO SEE THE SPECIES GET TO THE POINT WHERE IT--IT'S GOING TO DISAPPEAR.

NOBODY WANTS TO SEE THAT.

NARRATOR: THE MANATEES' HABITAT IS BEING REPLACED BY OURS...

BUT, IN A STRANGE TWIST TO THIS STORY, THAT'S NOT ALWAYS SUCH BAD NEWS.

IN WINTER, MANATEES HAVE STARTED TO HEAD TO THE CITY... TO THIS POWER STATION, TO BE PRECISE.

THE WARM OUTFLOW WATER IS A NEW HAVEN FOR THESE VULNERABLE CREATURES.

AROUND HALF OF ALL FLORIDA'S MANATEES NOW RELY ON POWER STATIONS FOR WARMTH... THEIR ROUND BODIES HOLDING ONTO THIS ESSENTIAL MAN-MADE HEAT TO GET THEM THROUGH WINTER.

THERE ARE PHYSICAL FORCES THAT SHAPE OUR WORLD.

GRAVITY AND THE ELECTROMAGNETIC BONDS BETWEEN MATTER ARE THE GREAT SCULPTURES OF OUR PLANET.

WHEN IT COMES TO LIFE, EVOLUTION PLAYS ITS PART.

PHYSICAL RULES ARE COMPROMISED...

BUT THERE'S ONE RULE OF SHAPE THAT IS FOUND EVERYWHERE-- SYMMETRY.

THERE IS A BEAUTY IN THE PERFECTION OF SYMMETRICAL PATTERNS.

SYMMETRY APPEARS TIME AND AGAIN IN THE SHAPE OF LIVING THINGS.

THAT'S BECAUSE IT'S USEFUL.

IT HELPS LIFE SURVIVE.

[WOMAN SPEAKING KOREAN ON P.A.]

[BIRDS CHIRPING] [SPEAKING KOREAN] NARRATOR: THESE WOMEN ARE ABOUT TO DO SOMETHING THAT WILL REVEAL WHY SYMMETRY IS ESSENTIAL TO LIFE... WHY SYMMETRY GOVERNS THE SHAPE OF NEARLY ANIMAL.

[MOTOR STARTS] THEY HAVE A UNIQUE AND INSPIRATIONAL WAY OF MAKING ENDS MEET.

[SPEAKING KOREAN] TRANSLATOR: I'M 74 YEARS OLD.

MY NAME IS JAE-SOON CHAE.

DIFFERENT TRANSLATOR: MY NAME IS SOON-DEOK KIM.

I AM 73.

NARRATOR: MRS. CHAE AND MISS KIM ARE OLD FRIENDS AND HAVE GROWN UP COLLECTING SEAFOOD ALONG THESE SHORES... AND THEY STILL DO IT.

THESE WOMEN ARE KNOWN AS HAENYEO, OR SEA WOMEN, PART OF A PROUD TRADITION.

[CHAE SPEAKING KOREAN] TRANSLATOR: WOMEN ARE TOUGH.

[KIM SPEAKING KOREAN] DIFFERENT TRANSLATOR: SO STRONG, AND SO WE CAN GO DIVING.

NARRATOR: THEY'LL TAKE WHICHEVER SEA CREATURES THEY FIND...

BUT RIGHT NOW, IT'S THE SEASON FOR COLLECTING CONCH.

FOR MISS KIM AND MRS. CHAE, THIS IS ALL ABOUT THE SEARCH FOR FOOD...

BUT THEY ARE CONNECTED TO THE SEA CREATURES WHICH THEY ARE HUNTING IN A MUCH MORE FUNDAMENTAL WAY.

WE ALL ARE.

WE ARE ALL CONNECTED THROUGH SYMMETRY.

IT'S A RULE OF SHAPE THAT EVOLVED IN EARTH'S ANCIENT OCEANS BILLIONS OF YEARS AGO.

EVOLUTION HAS TAKEN THIS RULE AND USED IT TO SHAPE LIFE.

AT FIRST GLANCE, IT LOOKS PURELY DECORATIVE, BUT IT'S MUCH MORE THAN THAT.

IT'S A RULE OF LIFE FOUND ACROSS THE ANIMAL KINGDOM.

LIFE IS, AND ALWAYS HAS BEEN, A COMPETITION.

IN AN ANCIENT, FREE-FLOATING WORLD, ANIMALS ADOPTED DIFFERENT TYPES OF SYMMETRY TO GET WHAT THEY NEEDED.

SOME ORGANISMS BECAME ROUND OR RADIALLY SYMMETRIC.

THEIR BODIES ARE ORGANIZED EQUALLY IN ALL DIRECTIONS AROUND A CENTRAL AXIS.

RATHER THAN HUNTING DOWN FOOD, THEY WAIT FOR FOOD TO COME TO THEM FROM ANY DIRECTION...

BUT TO GO ON THE HUNT, IT PAYS TO BE DIVIDED DOWN THE MIDDLE.

THIS BILATERAL SYMMETRY GIVES YOU A LEFT AND A RIGHT.

IT MEANS YOU DEVELOP A HEAD WITH SENSE ORGANS WHICH MEANS YOU CAN CONTROL DIRECTION, ORIENT YOURSELF, ESCAPE OR TARGET YOUR PREY.

[SPEAKING KOREAN] TRANSLATOR: GOT IT.

I'VE GOT AN OCTOPUS.

NARRATOR: A SYMMETRICAL BODY PLAN HAS BECOME PART OF NEARLY EVERY TYPE OF ANIMAL ON THE PLANET... FROM A PLANKTON TO A PERSON.

[SPEAKING KOREAN] TRANSLATOR: THERE ARE LOADS OF THEM HERE.

[KIM SPEAKING KOREAN] TRANSLATOR: ONCE YOU SEE THEM, YOU WANT TO GRAB THEM.

SHE GOES IN SLOWLY BY FLOATING...

BUT I JUST GO RIGHT IN, GO FOR IT.

I FEEL FREE.

IT'S LIKE FLYING.

[SPEAKING KOREAN] [SPEAKING KOREAN] TRANSLATOR: WHEN WE CATCH A LOT OF CONCH, I FEEL GOOD.

[ALL SPEAKING KOREAN] NARRATOR: THE RULES THAT GOVERN THE NATURAL WORLD ARE ALL AROUND US.

[BUZZING] [ROOSTER CROWS] WE CAN'T SEE THEM DIRECTLY, BUT WE CAN SEE THEIR SHADOWS IN THE SHAPES THAT MAKE UP OUR WORLD.

I GOT ONE.

NARRATOR: EVERY SHAPE WE SEE IS MADE FROM BUILDING BLOCKS...

BOUND BY THE FORCES OF NATURE... MOLDED BY GRAVITY... HONED BY EVOLUTION.

OUR PLANET IS MAGNIFICENTLY DIVERSE.

THE SHAPES OF ITS LIFE FORMS AND LANDSCAPES ARE FULL OF COMPLEXITY...

BUT ALL THIS EMERGES FROM A FEW SIMPLE RULES... AND THE FORCES OF NATURE.

♪ VO: Life.

♪ Life has taken the chemistry of the earth and made it its own.

♪ But what does it mean to be living?

♪ How could something so complex emerge from a barren rock.

♪