Dr. Kaku: FLYING RIGHT THROUGH THE HEART OF A BLACK HOLE...
HARNESSING THE ENERGY OF THE BIG BANG...
SHOOTING ALONG TUNNELS THROUGH SPACE-TIME ITSELF.
WE COULD BE HEADING BACK TO THE FUTURE SOONER THAN YOU THINK.
I'M DR. MICHIO KAKU.
I'M A THEORETICAL PHYSICIST AND A SCIENCE-FICTION FAN.
JOIN ME AS I SHOW YOU HOW TO MAKE SCI-FI SCIENCE.
IMAGINE ROCKETING THOUSANDS OF YEARS INTO THE FUTURE...
OR FLICKING A SWITCH AND HURTLING BACK INTO HISTORY.
I'M GONNA SHOW YOU HOW TO BUILD A TIME MACHINE.
...PROJECTING BACK INTO THE YEAR 1227 RIGHT NOW.
SET THE SOUND-WAVE SEGREGATOR
AND PATCH ME TO THE TIME-MACHINE AUDIO.
STOP THE CAR ABOUT HERE.
A JOURNEY BACK IN TIME TO VISIT THE DINOSAURS,
OR A TRIP TO SEE HOW THINGS PAN OUT IN THE 25th CENTURY --
TIME TRAVEL COULD MAKE EVERYONE'S DREAMS COME TRUE.
IN THE MOVIES, THERE ARE ALL KINDS OF TIME-MACHINE DESIGNS,
BUT WHAT EXACTLY DO THEY NEED TO DO?
WHO BETTER TO ASK THAN THE SCI-FI FANS?
THE BEST TYPE OF TIME MACHINE, OR EASIEST ONE TO TRY TO CREATE,
WOULD BE ONE THAT WOULD LET YOU GO FORWARD IN THE FUTURE
AND NOT AGE.
IT HAS TO GET UP TO 88 MILES PER HOUR
BEFORE THE FLUX CAPACITOR KICKS IN
AND IT PUSHES THEM BACK THROUGH TIME.
THERE'S "HARRY POTTER."
THEY HAVE THE LITTLE SPINNY THING
THAT TAKES THEM BACK IN TIME.
MY DESIGN REALLY WILL HAVE TO DO
JUST WHAT THOSE CRAZY INVENTIONS
FROM THE MOVIES CAN DO...
...TRAVEL TO THE FUTURE AND TRAVEL TO THE PAST.
I NEED TO BE ABLE TO SET THE DATE I WANT TO TRAVEL TO.
AND, OF COURSE, I NEED TO GET BACK TO THE PRESENT.
I DON'T WANT TO END UP STRANDED FOREVER.
[ CLOCK TICKING ]
BUT BEFORE TIME-TRAVELERS START THEIR JOURNEY,
THEY NEED TO UNDERSTAND HOW TIME WORKS
BECAUSE IT'S NOT WHAT IT APPEARS TO BE.
THIS IS WHERE IT ALL BEGINS.
THIS IS THE HOME OF TIME,
HERE AT THE ROYAL OBSERVATORY IN GREENWICH, ENGLAND.
TRADITIONALLY, ALL CLOCKS ON THE EARTH
WERE SYNCHRONIZED WITH RESPECT TO THAT LINE --
THE PRIME MERIDIAN.
ALTHOUGH THERE ARE DIFFERENT TIME ZONES ALL OVER THE WORLD,
TIME AS WE KNOW IT PASSES AT THE SAME RATE FOR EVERYONE.
GREENWICH MEAN TIME GIVES US THE ILLUSION
THAT THERE IS A GLOBAL CLOCK.
HOWEVER, THERE'S NO SUCH THING AS A UNIVERSAL NOON TIME.
TIME BEATS AT DIFFERENT RATES THROUGHOUT THE UNIVERSE.
TIME IS RELATIVE.
EINSTEIN FIGURED OUT TIME SPEEDS UP OR SLOWS DOWN
DEPENDING UPON HOW FAST ONE THING IS MOVING
RELATIVE TO SOMETHING ELSE.
HE CALLED IT THE SPECIAL THEORY OF RELATIVITY.
HERE'S HOW IT WORKS.
Man: ARE YOU GUYS READY TO RIDE ON THE RUNAWAY MINE TRAIN?
A-OKAY, THEN.
IMAGINE THIS ROLLER COASTER IS A ROCKET.
Dr. Kaku: A REALLY FAST ROCKET.
I'M FLYING THROUGH THE UNIVERSE
JUST A NOTCH BELOW THE SPEED OF LIGHT.
[ ROLLER COASTER CLATTERS, PEOPLE SCREAM ]
WHEN I LOOK AT MY WATCH, IT'S TICKING ONCE PER SECOND.
NO SURPRISES THERE.
BUT AS I HURTLE PAST THE WINDOW OF A SLOWER CRAFT
THE ASTRONAUTS CATCH A GLIMPSE OF MY WATCH THROUGH THE WINDOW,
AND TO THEM, IT'S BARELY MOVING.
IT'S LIKE WATCHING A MOVIE IN SLOW MOTION.
[ PEOPLE SCREAMING ]
THIS IS THE EFFECT OF TIME DILATION.
TIME APPEARS TO PASS MORE SLOWLY
FOR SOMEONE WHO IS MOVING THAN FOR SOMEONE WHO IS STATIONARY.
AND WHAT'S MORE,
THE FASTER YOU TRAVEL, THE MORE TIME SLOWS DOWN.
IT SOUNDS PRETTY FARFETCHED, BUT RELATIVE TO THE EARTH,
TIME BEATS AT DIFFERENT RATES THROUGHOUT THE UNIVERSE.
[ TRAIN WHISTLE BLOWS ]
EINSTEIN HAD THIS BRAINSTORM
WHEN THE FASTEST THING ON THE PLANET WAS A STEAM ENGINE.
IT TOOK US A WHILE
TO BUILD ANYTHING FAST ENOUGH TO PUT HIS THEORY TO THE TEST.
[ AIRPLANE ENGINE ROARS ]
1971 --
TWO PHYSICISTS STRAP AN EXTREMELY ACCURATE ATOMIC CLOK
INTO A JET PLANE.
IT FLIES EAST ALL THE WAY AROUND THE WORLD.
WHEN THE PLANE TOUCHES BACK DOWN, IT BECOMES CLEAR
THAT THE JET-SETTING CLOCK HAS TRAVELED IN TIME.
IT'S NOW 59 NANOSECONDS BEHIND THE CONTROL CLOCK
AT THE U.S. NAVAL OBSERVATORY.
EINSTEIN WAS RIGHT.
Woman: FOUR, THREE, TWO, ONE.
LIFTOFF, SPACE SHUTTLE DISCOVERY.
WHEN YOU'RE IN ORBIT, WHAT WE'RE ACTUALLY DOING
IS DELAYING THE FUTURE A LITTLE BIT.
Dr. Kaku: JEFFREY HOFFMAN IS A FORMER NASA ASTRONAUT,
BUT THAT'S NOT ALL HE IS.
HOFFMAN IS A TIME-TRAVELER.
DR. HOFFMAN HAS LOGGED MORE THAN 1,200 HOURS
AND 21 1/2 MILLION MILES IN SPACE.
THE VELOCITY, WHEN YOU'RE CLOSE TO THE EARTH IN ORBIT,
IS ABOUT 18,000 MILES AN HOUR.
THE FACT THAT YOU'RE GOING SO FAST
MEANS THAT THE CLOCKS THAT WE HAVE INSIDE THE SPACE SHUTTLE
MOVE JUST A LITTLE BIT SLOWER
THAN THE CLOCKS OF PEOPLE ON THE GROUND,
SO WHEN YOU COME BACK AFTER A SPACE MISSION,
YOU'VE AGED A LITTLE BIT LESS
THAN YOUR COMPANIONS BACK ON EARTH.
SO, AFTER THOUSANDS OF HOURS AT 18,000 MILES PER HOUR,
HOW FAR INTO THE FUTURE DID HOFFMAN TRAVEL?
DOING THE MATH THROWS UP A SLIGHTLY DISAPPOINTING ANSWER.
1 1/2 THOUSANDTHS OF A SECOND.
IT MIGHT NOT BE MUCH OF A JOURNEY IN TIME,
BUT IT IS A PROOF OF PRINCIPLE.
Man: THREE, TWO, ONE.
Dr. Kaku: I NEED TO TRAVEL A LOT FASTER
THAN HOFFMAN'S SPACE SHUTTLE, THOUGH.
THE FASTER I GO,
THE MORE I WILL EXPERIENCE TIME SLOWING DOWN.
I'LL BUILD THE FASTEST SPACECRAFT I CAN IMAGINE --
A SHIP POWERED BY ANTIMATTER.
IT'S THE MOST EFFICIENT, MOST EXPLOSIVE FUEL WE KNOW OF.
AND WITH ENOUGH OF IT,
I COULD POWER A SHIP TO 99% THE SPEED OF LIGHT.
THAT'S MORE THAN 37,000 TIMES THE SPEED OF THE SPACE SHUTTLE.
IF I WANT TO SEE WHAT THE WORLD LOOKS LIKE
WHEN I SHOULD BE LONG DEAD,
I SIMPLY HIT THE ACCELERATOR
AND TRAVEL AT FULL SPEED FOR 10 YEARS.
TIME DILATION TAKES EFFECT.
RELATIVE TO THE CLOCKS ON EARTH,
TIME IS BEATING SEVEN TIMES SLOWER.
FOR EVERY DAY I'M AWAY, I LOSE A WEEK BACK HOME,
SO WHEN I RETURN HOME, 70 YEARS WILL HAVE PASSED.
I'LL HAVE TRAVELED INTO THE FUTURE.
I THINK IT'LL WORK, BUT LET'S BE HONEST --
WHAT TIME-TRAVELER WANTS TO SPEND 10 YEARS
SITTING OUT IN OUTER SPACE?
IT'S HARDLY THE TIME MACHINE OF SCI-FI DREAMS.
MOST PEOPLE ASSUME THAT TIME TRAVEL IS IMPOSSIBLE.
BUT THEY ARE MISTAKEN.
I'VE WORKED OUT HOW TO TIME-TRAVEL
SIMPLY BY USING SPEED, BUT THE PROBLEM IS
THAT MY DESIGN DOESN'T REALLY DELIVER
THE KIND OF INSTANT TEMPORAL TRANSPORTATION
THAT I'M SURE SCI-FI FANS EXPECT.
OH, I DEFINITELY WANT TO PRESS A BUTTON AND BE THERE.
I'D BE WILLING TO SIT IN A TIME MACHINE FOR...
ABOUT 15 NANOSECONDS.
ANY LONGER THAN THAT, AND REALLY,
I DON'T THINK I'M GETTING MY BANG FOR THE BUCK.
TO BUILD A TIME MACHINE THAT WILL SATISFY THE SCI-FI FANS,
I NEED A NEW APPROACH.
EINSTEIN'S GENERAL THEORY OF RELATIVITY
COULD GIVE ME THE KEY TO MY DESIGN.
HE REALIZED THAT YOU CAN'T DETACH TIME FROM SPACE.
LET'S SAY THAT THIS BALL OF YARN IS SPACE
AND THIS BALL OF YARN IS TIME.
SPACE AND TIME CANNOT BE SEPARATED.
THEY'RE KNITTED TIGHTLY TOGETHER LIKE A FABRIC --
THE FABRIC OF SPACE-TIME.
LIKE ANY FABRIC,
SPACE-TIME TWISTS AND CURVES AND EVEN FOLDS BACK ON ITSELF.
JUST LIKE A FABRIC,
SPACE-TIME CAN BE STRETCHED, ROLLED, EVEN TORN.
IN OTHER WORDS, IT CAN BE MANIPULATED.
I'M GONNA EXPLOIT THIS CHARACTERISTIC
TO BUILD MY TIME MACHINE.
IN THEORY, IT'S STRAIGHTFORWARD.
EINSTEIN'S GENERAL THEORY OF RELATIVITY
COULD GIVE ME THE KEY TO MY DESIGN.
HE REALIZED THAT YOU CANNOT DETACH TIME FROM SPACE.
THAT'S BECAUSE MASS CREATES GRAVITY,
AND GRAVITY IS STRONG ENOUGH TO BEND SPACE-TIME.
FIND SOMETHING MASSIVE ENOUGH,
AND IT MIGHT CREATE A GRAVITY WELL --
A HUGE DIP IN THE FABRIC OF SPACE-TIME.
DR. MAREK KUKULA IS AN ASTRONOMER
AT THE ROYAL OBSERVATORY IN GREENWICH.
ALL MATTER HAS AN EFFECT ON THE FABRIC OF SPACE-TIME,
BUT THE MORE MASS THAT THERE IS, THE LARGER THE EFFECT.
THE OBJECT THAT WOULD HAVE THE MOST EFFECT
ON SPACE AND TIME AROUND IT WOULD BE A BLACK HOLE
SIMPLY BECAUSE THE GRAVITY AROUND A BLACK HOLE
IS THE MOST INTENSE THAT YOU CAN GET.
BECAUSE THE GRAVITY WELL CREATED BY A BLACK HOLE
IS SO DEEP, TIME WILL SLOW DOWN.
Dr. Kukula: THE TIME THAT WAS MEASURED
BY SOMEBODY CLOSE TO THE BLACK HOLE
WOULD RUN AT A SLOWER RATE THAN FOR SOMEBODY
WHO WAS FURTHER AWAY FROM THE BLACK HOLE.
SO, IN THAT SENSE,
YOU WOULD HAVE TRAVELED THROUGH TIME AT A DIFFERENT RATE
FROM SOMEONE WHO HAD STAYED HERE ON EARTH.
IF I COULD SURF AROUND THE EDGE
OF THE GRAVITATIONAL FIELD OF A BLACK HOLE,
I'D NOTICE NO DIFFERENCE IN THE PASSAGE OF TIME,
BUT WHEN I WENT BACK TO EARTH,
I'D FIND THAT I'D ARRIVED IN THE FUTURE.
BLACK HOLES CREATE COLOSSAL WELLS IN SPACE-TIME,
A PLACE WHERE HUGE PIECES OF SPACE-TIME
ARE DRAWN DOWN INTO A VERY SMALL AREA.
THE NEARER I GET TO ONE,
THE MORE SPACE-TIME I'M ACTUALLY CROSSING,
THE MORE TIME IS PASSING BY.
I THINK I CAN USE THIS PHENOMENON
FOR MY TIME-MACHINE DESIGN.
FIRST, I'LL NEED A SPACESHIP.
THEN I'LL NEED TO KNOW
HOW LONG TO CIRCLE AROUND THE BLACK HOLE.
MY SHIP WILL MEASURE ITS GRAVITATIONAL PULL.
THAT WAY, I WILL KNOW EXACTLY HOW LONG I MUST STAY IN ORBIT
IN ORDER TO ARRIVE BACK ON EARTH
AT THE DATE IN THE FUTURE THAT I WANT.
OF COURSE, THE EDGE OF A BLACK HOLE --
WHAT'S CALLED THE EVENT HORIZON --
IS A HIGHLY DANGEROUS PLACE TO SPEND ANY TIME AT ALL.
GRAVITY POWERFUL ENOUGH TO WARP SPACE-TIME
WOULD EASILY BREAK ME AND MY CRAFT
BACK DOWN INTO THE ATOMS WE'RE MADE OF.
EVEN IF I COULD CRACK THE ENGINEERING CHALLENGE
OF ACTUALLY GETTING NEAR THE EVENT HORIZON,
THERE'S STILL A MAJOR FLAW IN THIS DESIGN.
GRAVITY ALLOWS A TIME-TRAVELER TO COVER MORE TIME
RELATIVE TO ANYONE WHO ISN'T NEAR A BLACK HOLE.
WHEN HE ESCAPES THE GRIP OF THE BLACK HOLE,
HE'LL JUMP INTO THE FUTURE.
BUT GRAVITY CAN'T SPEED UP MY EXPERIENCE OF TIME,
SO I CAN'T PULL OFF THE OPPOSITE TRICK
AND TRAVEL TO THE PAST.
I STILL THINK THAT USING THE EFFECT OF GRAVITY
MAY HOLD THE ANSWER.
I'M BUILDING A TIME MACHINE.
SO FAR, MY DESIGN ONLY GIVES ME A ONE-WAY TICKET TO THE FUTURE.
I NEED TO FIND A WAY TO WARP SPACE-TIME
SO THAT I CAN TRAVEL IN BOTH DIRECTIONS.
PHYSICIST RICHARD GOTT CAME UP WITH A NOVEL DESIGN
FOR A TIME MACHINE THAT JUST MIGHT WORK.
HIS IDEA IS BASED ON A MYSTERIOUS PHENOMENON
CALLED A COSMIC STRING.
THEY'RE LIKE STRANDS OF GALACTIC SPAGHETTI.
BON APPéTIT.
SCIENTISTS BELIEVE THAT COSMIC STRINGS WERE FORMED
AT THE BIRTH OF THE UNIVERSE, DURING THE BIG BANG.
BITS OF THIS INTENSE PRIMORDIAL ENERGY WERE TRAPPED
AND LOCKED IN TUBES LESS THAN AN ATOM THICK
FOR ALL TIME.
BECAUSE THEY CONTAIN CONCENTRATED ENERGY,
THEY ARE INCREDIBLY DENSE.
AS EINSTEIN FOUND OUT, MASS AND ENERGY ARE RELATED.
THAT'S BECAUSE E EQUALS MC SQUARED.
THIS MUCH ENERGY CONCENTRATED INTO SUCH A SMALL SPACE
CREATES MASS -- A LOT OF MASS.
A COSMIC STRING JUST A HALF A MILE LONG
MIGHT BE HEAVIER THAN THE EARTH.
THEY COULD STRETCH THE LENGTH OF THE ENTIRE UNIVERSE.
IT MIGHT CONTAIN THE ENERGY OF HALF A GALAXY.
JUST THINK HOW SOMETHING THIS MASSIVE
MUST WARP THE FABRIC OF SPACE-TIME.
GOTT BELIEVES THAT WHEN TWO STRINGS
ARE IN JUST THE RIGHT CONFIGURATION,
A SPACESHIP COULD TRAVEL THROUGH TIME.
IMAGINE THAT THE LOOP OF TRACK IS SPACE-TIME
AND THAT THIS TRAIN IS A SPACESHIP.
LET'S SAY THE SPACESHIP
WANTS TO TAKE A JOURNEY THROUGH SPACE-TIME,
SO IT TRAVELS ALL THE WAY AROUND THE LOOP.
GOTT THINKS THAT BECAUSE COSMIC STRINGS
ARE SO INCREDIBLY DENSE,
THEY MUST WARP SPACE-TIME IN A VERY STRANGE WAY.
IT'S LIKE THERE'S A MISSING WEDGE TAKEN OUT OF SPACE-TIME
AND THE TWO SIDES ARE PULLED TOGETHER.
THE MISSING SPACE-TIME IS LOST,
AND, FOR ALL PRACTICAL PURPOSES,
IT WOULD CEASE TO EXIST.
PASSENGERS ON THE SPACESHIP WOULD DETECT NO DIFFERENCE,
BUT THEIR JOURNEY WOULD SPEED UP INCREDIBLY
AS THEIR SHIP LEAPED ACROSS GIANT SPANS OF SPACE-TIME
AND THEREFORE, OF TIME ITSELF.
THESE LEAPS LET THE SPACESHIP JUMP INTO THE FUTURE.
BUT WHAT'S EVEN MORE EXCITING FOR MY TIME-MACHINE DESIGN
IS THAT IF THE STRINGS CAN BE MADE TO MOVE PAST EACH OTHER,
THEY CREATE A UNIQUE VORTEX SHAPE
IN THE FABRIC OF SPACE-TIME.
THIS SHAPE MEANS
THE SPACESHIP WILL ARRIVE BACK AT ITS STARTING POINT
BEFORE IT HAS LEFT.
IT WILL HAVE TRAVELED INTO THE PAST.
COSMIC STRINGS ARE CERTAINLY MASSIVE ENOUGH
TO MANIPULATE SPACE AND TIME
AND ALLOW ME TO TRAVEL INTO THE FUTURE AND THE PAST.
BUT TO BUILD A WORKING, PRACTICAL TIME MACHINE
OUT OF COSMIC STRINGS IS GONNA BE REAL TOUGH.
COSMIC STRINGS MIGHT WEIGH AS MUCH
AS 200 MILLION BILLION TONS AN INCH.
THE ONLY WAY TO MOVE SOMETHING THIS COLOSSAL
IS WITH GRAVITY.
MY SHIP WILL NEED TO HAVE A MASS
MORE THAN 300 TIMES THAT OF THE EARTH.
IT'LL NEED TO BE AS BIG AS JUPITER
JUST TO HAVE EVEN A LITTLE GRAVITATIONAL EFFECT
ON A STRING.
THEN MY ORIGINAL ANTIMATTER ROCKET SHIP
COULD POP OUT OF A MASSIVE MOTHER SHIP
AND ZIP BACKWARDS IN TIME.
THERE'S ONLY ONE PROBLEM --
NO ONE HAS EVER SEEN A COSMIC STRING.
GOTT'S THEORY HAS CONVINCED ME
THAT MANIPULATING THE FABRIC OF SPACE-TIME
CAN MAKE TIME TRAVEL POSSIBLE.
I'VE JUST GOT TO FIND AN EASIER WAY TO DO IT.
Dr. Kaku: I NEED A WAY TO WARP SPACE-TIME
SO THAT I CAN LEAP THROUGH TIME.
COSMIC STRINGS WOULD DO THE JOB,
BUT I MIGHT WASTE A LIFETIME TRYING TO TRACK THEM DOWN.
INSTEAD, I THINK I NEED TO EXPLOIT
THE ENORMOUS ENERGY OF BLACK HOLES.
WE ALREADY KNOW THAT FLYING OUR SPACESHIP NEAR THEM
WOULD EFFECTIVELY SLOW DOWN TIME
SO THAT I COULD TRAVEL TO THE FUTURE.
BUT WHAT ABOUT TAKING AN EVEN MORE RADICAL APPROACH --
FLYING RIGHT THROUGH ONE,
JUST LIKE SPOCK DOES IN THE LAST "STAR TREK" MOVIE?
A BLACK HOLE IS AN OBJECT SO MASSIVE
THAT EVEN LIGHT ITSELF CANNOT ESCAPE.
ITS GRAVITY FIELD IS SO INTENSE
THAT IT ACTUALLY RIPS THE FABRIC OF SPACE AND TIME.
AND A HOLE IN THE FABRIC OF SPACE-TIME
COULD BE LIKE ALICE'S LOOKING GLASS --
WE COULD JUST JUMP THROUGH AND TRAVEL TO A DIFFERENT TIME.
BUT THERE'S A PROBLEM.
FALLING INTO A BLACK HOLE IS NO PICNIC.
THE RADIATION FIELDS ARE SO FIERCE
THAT YOU COULD BE BURNT TO A CRISP,
AND THE GRAVITY IS SO STRONG
THAT EVEN YOUR ATOMS COULD BE RIPPED APART
INTO SUBATOMIC PARTICLES.
BUT THERE MIGHT BE A WAY OF AVOIDING THIS AWFUL FATE.
IT'S RECENTLY BEEN DISCOVERED THAT MOST BLACK HOLES SPIN,
SO THE BLACK HOLE COLLAPSES NOT TO A SINGLE POINT,
BUT TO A RING.
ALL THE TERRIFYING FORCES ARE PUSHED TO THE OUTSIDE.
THE CENTER IS A FAR CALMER PLACE THAN WE HAD IMAGINED --
JUST LIKE THE EYE OF A HURRICANE.
OF COURSE, NO ONE HAS EVER FLOWN THROUGH A BLACK HOLE
TO KNOW WHAT'S THERE FOR SURE,
BUT THE MATH TELLS US
THAT AT THE HEART OF EVERY ONE IS A WORMHOLE,
AND THAT'S WHERE THINGS GET INTERESTING
FOR MY TIME MACHINE.
JUST LIKE THE EARTH, SPACE-TIME SEEMS LIKE IT'S FLAT,
LIKE EVERYTHING IS ON A SINGLE PLANE,
BUT SPACE-TIME IS NOT FLAT.
IT BENDS, FOLDS, AND CURVES.
WORMHOLES ARE FORMED AT THE CENTER OF A BLACK HOLE.
THEY WARP THE FABRIC OF SPACE-TIME
TO CREATE A TUNNEL CONNECTING DISTANT POINTS.
THEY MIGHT BE IDEAL FOR TIME TRAVEL,
AS THEY WOULD OFFER A SHORTCUT THROUGH SPACE AND TIME.
BUT WOULD FLYING THROUGH THEM REALLY WORK?
Dr. Tegmark: BLACK HOLES EXIST,
AND WE KNOW HOW TO BUILD ROCKETS,
AND THAT'S REALLY ALL THERE IS TO IT.
THEORETICAL PHYSICIST MAX TEGMARK BELIEVES
THAT WORMHOLES COULD INDEED BE THE KEY TO TIME TRAVEL.
EINSTEIN TOLD US
THAT SPACE IS MUCH MORE INTERESTING THAN WE THOUGHT
AND IT CAN ACTUALLY HAVE SHORTCUTS THROUGH IT,
SO IF WE IMAGINE
THAT WE WENT INTO ONE END OF SUCH A SHORTCUT,
WE WOULD APPEAR
THROUGH THE OTHER END OF THE WORMHOLE INSTANTLY,
WITHOUT ANY DELAY.
MAX GOES EVEN FURTHER.
HE BELIEVES THAT IT MIGHT ONE DAY BE POSSIBLE
TO MOVE THE WORMHOLES AROUND
AND PLACE THEM WHERE YOU WANT IN SPACE-TIME.
Dr. Tegmark: SO, YOU MIGHT EVEN CREATE A LITTLE SYSTEM OF WORMHOLES --
YOU KNOW, THE ONE-DAY WORMHOLE, THE ONE-WEEK WORMHOLE,
THE ONE-MONTH WORMHOLE, AND THE ONE-YEAR WORMHOLE.
SO IF YOU WANT TO GO BACK TO A SPECIFIC DATE,
YOU'LL BE TOLD BY YOUR TRAVEL AGENT
TO GO THROUGH THIS ONE THREE TIMES
AND THEN THAT ONE FOUR TIMES AND THEN THIS ONE TWICE,
[ SNAPS FINGERS ] AND YOU'RE THERE.
BUT IT WOULD TAKE UNIMAGINABLE AMOUNTS OF ENERGY
TO RIP SPACE-TIME AND DIG TUNNELS THROUGH IT.
IT MIGHT BE HUNDREDS OF THOUSANDS OF YEARS
BEFORE WE COULD DO THIS.
AND THERE'S AN EVEN BIGGER PROBLEM.
WORMHOLES ARE HIGHLY UNSTABLE
AND WOULD PROBABLY COLLAPSE INSTANTLY
IF EVEN THE TINIEST AMOUNT OF MATTER
TRIED TO PASS THROUGH THEM.
BUT I THINK WE CAN GET AROUND THAT
AND BUILD A TIME MACHINE A WHOLE LOT SOONER.
TIME TO TAKE MY DESIGN FOR A TEST-DRIVE
WITH THE SCI-FI FANS.
[ APPLAUSE ]
LADIES AND GENTLEMEN, TODAY, I'M VERY PROUD TO PRESENT TO YOU
THE WORLD'S FIRST WORKABLE TIME MACHINE.
SO, THE QUESTION IS, HOW WOULD WE DO IT?
LISTEN CAREFULLY.
FIRST, MY DESIGN NEEDS A BLACK HOLE
WITH A WORMHOLE AT ITS CENTER.
A WORMHOLE IS A SHORTCUT THROUGH THE FABRIC OF SPACE AND TIME,
CONNECTING ONE POINT WITH ANOTHER POINT.
THEN I NEED TO SOMEHOW STABILIZE THE WORMHOLE
SO MY SPACESHIP CAN FLY THROUGH
WITHOUT BEING CRUSHED TO NOTHING.
I NEED SOMETHING THAT WILL COUNTERACT
THE EFFECT THAT MATTER HAS ON SPACE-TIME.
I NEED NEGATIVE MATTER.
HOW WOULD SUCH A SUBSTANCE BEHAVE?
IT WOULDN'T FALL DOWN -- IT WOULD FALL UP.
IT HAS ANTIGRAVITATIONAL PROPERTIES,
SO IT WOULD BE REPELLED FROM THE EARTH.
SO IN OUTER SPACE,
THERE ARE FRAGMENTS OF NEGATIVE MATTER
LEFT OVER FROM THE BEGINNING OF THE UNIVERSE.
FOR A STANDARD-SIZE SPACESHIP TO PASS THROUGH,
YOU NEED A CHUNK OF NEGATIVE MATTER
THE SIZE OF A PLANET.
I'LL TRACK ONE DOWN IN DEEP SPACE
AND HOLLOW IT OUT SO THAT MY SHIP FITS INSIDE.
BECAUSE IT'S THE OPPOSITE OF NORMAL MATTER,
IT WILL BE REPELLED
BY THE GRAVITATIONAL PULL OF MY SPACECRAFT,
WHICH MEANS THAT IT WON'T CRUSH OR DESTROY THE SHIP.
AND THEN YOU ALLOW YOURSELF TO FALL RIGHT INTO THE BLACK HOLE.
NEGATIVE MATTER HOLDS THE GATEWAY OPEN LONG ENOUGH
SO THAT YOU CAN GO RIGHT THROUGH WITHOUT BEING CRUSHED TO DEATH.
IN AN INSTANT, I'LL HAVE TRAVELED BACK IN TIME.
BUT THEN, THE LAST QUESTION IS,
CAN YOU TURN A DIAL AND GO TO ANY TIME PERIOD YOU WANT?
WELL, MY DESIGN CAN'T DO THAT YET,
BUT I BELIEVE THAT IN MY LIFETIME,
WE WILL HAVE A THEORY OF EVERYTHING
WHICH WILL ALLOW US TO CALCULATE
HOW MUCH NEGATIVE MATTER IS NECESSARY
TO STABILIZE A WORMHOLE
AND TO DETERMINE WHERE AND WHEN WE'LL WIND UP.
[ APPLAUSE ]
I THINK THE TIME MACHINE WAS SO AWESOME.
IT'S INCREDIBLE TO THE IMAGINATION.
THAT WOULD SCARE THE LIFE OUT OF ME.
I JUST HOPE, ONE DAY, WE CAN PUT IT TO THE TEST.