>> Stephen: WELCOME BACK,
EVERYBODY. MY NEXT GUEST IS A PROFESSOR OF
PHYSICS AND MATHEMATICS AT COLUMBIA UNIVERSITY AND
COFOUNDER OF THE WORLD SCIENCE FESTIVAL. PLEASE WELCOME PROFESSOR BRIAN
GREENE. ♪ ♪ ♪
>> THANK YOU, MAN. GOOD DRIVING. >> Stephen: THANK YOU FOR
BEING HERE, THANK YOU. <i>( CHEERS )
HOW DO YOU-- HOW DO YOU LIKE THE</i> SCIENCE MOBILE? >> OH, MAN, WAS THAT THE THE
INAUGURAL RUN OF IT. >> Stephen: THAT WAS THE FIRST
TIME WE USED THE SCIENCE MOBILE. YOU CAN RENT THAT FOR
CONVENTIONS. TELL YOUR SCIENCE FRIENDS. >> I WILL LET THEM ALL KNOW. >> Stephen: IT'S AVAILABLE. YOU ARE HERE NOT ONLY BECAUSE
YOU'RE A FASCINATING GUY TO TALK TO-- THANK YOU FOR BEING AT MY
LAST SHOW AT THE OLD GIG. >> I LOVED IT. THANK YOU. >> Stephen: BUT, ALSO, THIS IS
THE 100th ANNIVERSARY, THIS MONTH, OF EINSTEIN PRESENTING
HIS GENERAL THEORY OF RELATIVITY. ALL RIGHT. I KNOW IT'S FAMOUS. OKAY? ( LAUGHTER )
WHY IS IT EPOCH MAKING? WHY DID IT CHANGE EVERYTHING? >> SO WE DID NOT UNDERSTAND HOW
THE FORCE OF GRAVITY WORKED BEFORE EINSTEIN GAVE US THE
GENERAL THEORY. >> Stephen: DID NEWTON TEACH
US THAT GRAVITY COMES FROM APPLES? >> THAT'S WHAT YOU WOULD THINK. ( LAUGHTER )
THAT'S WHAT YOU WOULD THINK. BUT ACTUALLY, WHAT NEWTON GAVE
US IS A FORMULA THAT TELLS US THE STRENGTH OF GRAVITY, BUT HE
NEVER TOLD US HOW GRAVITY ACTUALLY EXERTS ITS PULL. >> Stephen: DID HE NOT CARE? >> HE CARED. IN FACT IN HIS OWN WRITING HE
SAID THAT IT WAS A CRITICAL QUESTION THAT NEEDED TO BE
ADDRESSED BUT HE SAID, "I WILL LEAVE IT TO THE CONSIDERATION OF
THE READER." HE COULDN'T FIGURE IT OUT. >> Stephen: SO THEN EINSTEIN
READ THAT AND SAID, "I GOT THIS ONE. I GOT THIS ONE." >> THAT'S RIGHT, THAT'S EXACTLY
RIGHT. >> Stephen: STAND BACK, GUYS,
ALBY IS HERE. SO WHEN DOES SPECIAL RELATIVITY
COME OUT? >> 1905. >> Stephen: WHAT IS WHAT YOU
CALL ANAS MIRABULOUS. >> RELATIVITY IS THE MOST FAMOUS
WHERE HE REDEFINED OUR UNDERSTANDING OF SPACE AND TIME. >> Stephen: IS THAT E.EQUALS
MC SQUARED. >> IT WAS AN AFTERTHOUGHT OF THE
SPECIAL THEORY OF RELATIVITY. >> Stephen: BY THE WAY, E. EQUALS MC SQUARED. >> HE PUBLISHED SPECIAL
RELATIVITY AND IN SEPTEMBER HE HAS A LITTLE EXTRA IDEA, WHICH
IS E. EQUALS MC SQUARED. >> Stephen: SO THIS IS 10
YEARS LATER. AND HAS HE GOT ANY HITS IN
BETWEEN THOSE TWO? >> HE PUBLISHED ENORMOUS NUMBERS
OF PAPERS BUT HIS REAL FOCUS, THE PASSION OF HIS LIFE'S WORK,
WAS TO FIGURE OUT GRAVITY. >> Stephen: AND HOW DID-- HOW
DID IT COME TO HIM THAT-- HOW THIS WORKS? ( LAUGHTER ). >> WELL, YOU KNOW--
>> Stephen: I DON'T EVEN KNOW HOW TO FORM THE QUESTION. >> HE WAS DEEPLY PUZZLED. HOW DOES THE SUN KEEP THE EARTH
IN ORBIT? WHAT IS GRAVITY. AND HE'S THINKING ABOUT THIS,
THINKING ABOUT THIS. AND ONE DAY IN 1907, HE'S IN THE
PATENT OFFICE IN SWITZERLAND WHERE HE WORKED, AND HE HAD WHAT
HE CALLED THE HAPPIEST THOUGHT OF HIS LIFE. >> Stephen: WOW. >> AND THE THOUGHT --
>> IS THAT SOMETHING THAT WE CAN SAY? >> WE CAN TALK ABOUT IT. I DON'T KNOW ABOUT YOUR HAPPIEST
THOUGHT, BUT HIS WE WITH TALK ABOUT. ( LAUGHTER )
( APPLAUSE ) SO HE IMAGINES A MAN FALLING
FROM THE ROOF OF A HOUSE. ( LAUGHTER ). >> Stephen: HAPPY! YAY! >> AND HE REALIZES THAT THAT MAN
WOULD NOT FEEL HIS OWN WEIGHT. HE WOULD FEEL WEIGHTLESS. >> Stephen: IN FREEFALL. >> FREEFALL. HE'S ON A SCALE. AND THE SCALE'S READING WOULD
FALL TO ZERO BECAUSE HE'S NO LONGER PUSHING ON THE SCALE. HE'S FALLING WITH IT. >> Stephen: I UNDERSTAND
THERE'S AN EXPERIMENT TO DEMONSTRATE THAT. >> YES, A SIMPLE DEMONSTRATION. ( APPLAUSE ). >> Stephen: YEAH! OKAY. DO I HAVE TO DO ANYTHING? >> NO, IT'S VERY SIMPLE. ALL WE HAVE HERE IS A BOTTLE OF
WATER THAT HAS HOLES IN IT, RIGHT? SO, OF COURSE, THE WATER IS
SPRAYING OUT OF THE HOLES BECAUSE GRAVITY IS PULLING ON
THE WATER, RIGHT? >> Stephen: RIGHT. >> BUT IF EINSTEIN IS RIGHT, IF
I DROP THIS BOTTLE, THE WATER WILL NO LONGER FEEL GRAVITY, SO
THE WATER SHOULD STOP SPRAYING OUT. LET'S SEE IT, THREE, TWO, ONE. >> Stephen: WHOA! ( CHEERS AND APPLAUSE )
WOW. OKAY. NOW, DID EINSTEIN-- DID EINSTEIN
HAVE ANY THEATERIES ABOUT WHO'S GOING TO CLEAN THAT UP RIGHT
NOW? SO HE SAW, THAT HE THOUGHT OF
THAT, AND THEN GENERAL RELATIVITY. >> EIGHT YEARS IN THE MIND OF
ALBERT EINSTEIN. >> Stephen: SO HE THINKS ABOUT
IT FOR EIGHT YEARS. WHAT'S NEXT? >> THEN HE REALIZES THAT THERE'S
A LINK BETWEEN GRAVITY AND MOTION. >> Stephen: LET'S-- WE HAVE
ANOTHER EXPERIMENT. >> HE COMES UP WITH THIS IDEA
FOR HOW GRAVITY WORKS. THIS IS MEANT TO BE THE FABRIC
OF SPACE. >> Stephen: OKAY. IT'S BLARK IT'S BLACK. >> IT'S BLACK, RIGHT, EXACTLY. HE SAYS IF THERE'S NO MATTER, NO
ENERGY IN SPACE AND IT'S FLAT WHICH WOULD MEAN IF YOU ROLL
SOMETHING-- SAY A PLANET IS MOVING THROUGH SPACE, IT GOES ON
A STRAIGHT LINE. BUT NOW LET'S BRING IN THE SUN. THIS IS THE SUN RIGHT HERE. AND HE SAYS IN THE GENERAL
THEORY OF RELATIVITY, THAT THE SUN, MERELY BY VIRTUE OF BEING
IN SPACE, WARPS THE FABRIC OF SPACE, ACTUALLY AND TIME. AND THAT'S VITAL. >> Stephen: IT MAKES LIKE A
>> A WELL IN A SENSE. BECAUSE NOW IF WE TAKE THE
EARTH, RIGHT, AND SET IT IN MOTION, IT NOW GOES INTO ORBIT,
BECAUSE THE FABRIC OF SPACE IS NUDGING IT AROUND. AND THAT IS, ACCORDING TO
EINSTEIN, HOW GRAVITY WORKS. SO IF WE GET THESE GUYS MOVING,
ALL OF THESE PLANETS, OBJECTS-- I THINK I JUST THREW SOMETHING
OFF THE EDGE OF THE UNIVERSE. ( LAUGHTER )
THIS ACCORDING TO EINSTEIN IS HOW THE FORCE OF GRAVITY
ACTUALLY WORKS. WE CAN PUT SOME, LET'S SAY
ASTROADSIDE, IN THERE, AND LET THEE GUYS GO IN MOTION. GO CRAZY. GO CRAZY. >> Stephen: DO I HAVE TO GO IN
THE SAME DIRECTION? >> IT'S UP TO YOU, MAN. GO NUTS. RIGHT OFF THE EDGE OF THE
UNIVERSE AGAIN! >> Stephen: I THINK I'VE TORN
THE FABRIC OF SPACE TIME. >> AND THEN WE HAVE SOME OF
THESE GUYS OVER HERE. >> Stephen: WOW. AND THOSE PLANETS ARE ON FIRE? ( LAUGHTER )
>> THERE THEY ARE. >> Stephen: I'VE GOT ONE MORE
QUESTION FOR YOU. EVERYBODY ALWAYS SAYS THIS IS--
THIS IS A BEAUTIFUL DEMONSTRATION. EVERYONE ALWAYS SAYS TO GUYS
LIKE YOU, "CAN YOU DUMB IT DOWN TO THE LEVEL OF, LIKE, A
FIVE-YEAR-OLD?" I WOULD LIKE YOU TO NOT DUMB IT
DOWN. I WOULD LIKE YOU TO SAY IT TO ME
AS IF I WERE MY AGE, 51, BUT HAD AN ADVANCED DEGREE IN PHYSICS
AND HIGH MATHEMATICS. GIVE IT TO ME IN LESS THAN 30
SECONDS, BUT LET ME JUST LEAN INTO MY IGNORANCE OF WHAT YOU'RE
SAYING TO ME. >> SO ALBERT EINSTEIN SAYS THAT
SPACE TIME IS A FOUR-DIMENSIONAL HOUSES DIFFERENTIAL MANIFOLD ON
WHICH A METRIC TENSOR IS IMPOSED THAT SOLVES THE EINSTEIN FIELD
EQUATIONS, AND THAT METRIC TENSOR GIVES RISE TO GEODESICS
AND OBJECTS NOT EXPERIENCE ANYTHING OTHER FORCE MOVE ALONG
THE GEODESICCS DESCRIBED BY THAT METRIC. ( CHEERS AND APPLAUSE )
>> Stephen: THAT'S-- THAT'S-- THAT'S ( BLEEP ) RIGHT THERE! BRIAN GREENE, EVERYBODY. THANK YOU SO MUCH. HAPPY BIRTHDAY, GENERAL
RELATIVITY. WE'LL BE RIGHT BACK.
They also unintentionally demonstrated why all objects in our solor system(and other systems) orbit in the same direction.
While they were throwing more and more marbles on the fabric, Stephen at one point said, "This way too?!", asking if he should throw some in the opposite direction they were all orbiting.
When he threw the marbles in the other direction, all his marbles collide with marbles from the opposite direction, leaving only marbles going in the original direction.
Sorry for the rough explanation, funnily enough I just learned this fact myself.
https://www.youtube.com/watch?v=MTY1Kje0yLg he does the same thing for this class.