Transcript: Joao Magueijo on The Changed Laws of Physics | Oct 14, 2006

[Theme music plays]

The opening sequence rolls. The logo of "Big Ideas" featuring a lit lamp bulb appears against an animated yellow slate.
Then, Andrew Moodie appears in the studio. The walls are decorated with screens featuring lit lamp bulbs, and two signs read "Big Ideas."
Andrew is in his early forties, clean-shaven, with short curly black hair. He's wearing a blue shirt.

As he wipes the lenses in a pair of binoculars, Andrew says HELLO, I'M
ANDREW MOODIE, THIS IS
BIG IDEAS.
DON'T MIND ME, MY DAUGHTER AND
I ARE GOING TO BE LOOKING AT
THE STARS LATER ON TONIGHT, AND
THEY SAY IT'S ACTUALLY BETTER
TO USE A PAIR OF THESE, THAN TO
USE A TELESCOPE.
WELL, AT LEAST FOR THE AMATEUR
ASTRONOMER.
MY DAUGHTER JUST TURNED 3, AND
SUDDENLY SHE'S ASKING ME ALL
THESE QUESTIONS, OKAY?
LIKE, JUST YESTERDAY, SHE ASKED
ME, "DADDY, WHAT ARE BODIES FOR?"
WHAT ARE BODIES FOR?
HOW AM I SUPPOSED TO RESPOND TO THAT?
"WELL, HONEY, THEY HELP US TO
PERCEIVE EXISTENCE THROUGH
NERVES THAT ARE SENSITIVE TO A
BAND OF ELECTROMAGNETISM WE
CALL LIGHT, FLUCTUATIONS OF
OXYGEN WE CALL SOUND, AND OTHER
OBJECT AND SPACE TIME THROUGH
TOUCH."
3 YEARS OLD... ALWAYS ASKING
QUESTIONS.
WELL, YOU KNOW, I SUPPOSE I
SHOULD BE THANKFUL THAT AT
LEAST I'M NOT JOAO MAGUEIJO'S
FATHER.
YOU SEE, BACK IN 1995, MAGUEIJO
WANTED TO KNOW WHY DID THE
UNIVERSE SUDDENLY EXPAND IN
LESS THAN A BILLIONTH OF A
TRILLIONTH OF A TRILLIONTH OF A
SECOND, DOUBLING IN SIZE OVER
AND OVER AND OVER AGAIN, UNTIL
A COSMOS, FAR SMALLER THAN A
SINGLE PROTON, GREW TO BE THE
SIZE OF A GRAPEFRUIT?
NOW AS LEGEND HAS IT, MAGUEIJO
WAS HUNG OVER, TRUDGING ACROSS
A SOGGY SOCCER FIELD ONE
WINTER'S MORNING IN CAMBRIDGE,
WHEN SUDDENLY THE IDEA STRUCK
HIM...
WHAT IF EINSTEIN WAS WRONG?
WHAT IF THE SPEED OF LIGHT IS
NOT CONSTANT?
WELL THEN, YOU KNOW, I GUESS WE
JUST TOSS OUT THE FOUNDATIONS
OF HOW WE CAME TO COMPREHEND
SPACE TIME.
HMM... SO YOU CAN UNDERSTAND
WHY SOME PEOPLE ARE JUST A
LITTLE UPSET.
MAGUEIJO IS A COSMOLOGIST, AND
LECTURER IN THEORETICAL PHYSICS
AT IMPERIAL COLLEGE, LONDON.
HIS BOOK,
FASTER THAN THE
SPEED OF LIGHT, THE STORY
OF A SCIENTIFIC
SPECULATION, IS A
FASCINATING LOOK AT THE
CONTROVERSY SURROUNDING THE
VARYING SPEED OF LIGHT THEORY,
AS WELL AS A HARSH CRITIQUE OF
ACADEMIA.
GET YOURSELVES READY FOR A
WHOLE NEW UNIVERSE WITH JOAO
MAGUEIJO, SPEAKING AT THE
PERIMETER INSTITUTE.

A clip plays which starts with a slate showing a picture of Joao Magueijo. He's in his late thirties, clean-shaven, with short brown hair. The slate reads "Joao Magueijo. Imperial College London and Perimeter Institute. Faster than the speed of light – Could the laws of physics change? June 23, 2006. Special Guelph Lecture: Rozanski Hall, University of Guelph Campus.

Then, Joao stands in a hall by a large projecting screen. He's wearing a white printed long-sleeved T-shirt.

He says SO WHAT I WILL
BE TALKING ABOUT TODAY IS A
SOMEWHAT PHILOSOPHICAL ISSUE.
IT MIGHT SOUND LIKE A
METAPHYSICAL ISSUE.
ESSENTIALLY THIS QUESTION,
COULD THE LAWS OF PHYSICS
CHANGE?
AND I SHOULD WARN YOU
IMMEDIATELY, I'M NOT GOING TO
ANSWER THE QUESTION.

[Audience laughter]

Joao continues AND WHAT I'M GOING TO TRY TO DO
IS SHOW THAT THIS IS ACTUALLY,
ALTHOUGH IT SOUNDS
PHILOSOPHICAL, IT CAN BE CAST
IN A VERY PHYSICAL, VERY
PHYSICS BASED LANGUAGE, AND
THAT'S PRECISELY WHERE THE IDEA
FOR VARIANT SPEED OF LIGHT
COMES IN.
SO BY THIS, I SHOULD WARN YOU,
I MEAN, THIS IS NOT--
I'M NOT SAYING THE LAWS OF
PHYSICS CHANGE BECAUSE WE
REALISE WE MADE A MISTAKE, AND
THEREFORE OUR PERCEPTION OF THE
LAWS OF PHYSICS CHANGE.
I MEAN THE LAWS THEMSELVES
CHANGING, AND IT IS A REALLY
KIND OF CONTROVERSIAL THING.
WHAT YOU'RE SAYING IS THAT THE
UNIVERSE IS MAKING THINGS UP AS
IT GOES ALONG, THAT THERE IS
THIS IDEA THAT YOU KNOW, THE
UNIVERSE EVOLVES AND THE RULES
IT USES FOR ITS DEVELOPMENT,
THE RULES THEMSELVES COULD
ACTUALLY BE CHANGING IN TIME.
AND THIS IS-- IF YOU THINK A
BIT ABOUT THIS, THIS IS
ACTUALLY QUITE DIFFICULT TO
IMPLEMENT IN ANY KIND OF
FRAMEWORK, BECAUSE IF THE LAWS
ARE CHANGING, IT COULD BE THERE
IS ANOTHER LAW ABOVE IT THAT'S
TELLING HOW THE LAWS WE SEE ARE
CHANGING.
SO THERE COULD BE A SUPER LAW
WE WOULDN'T BE SEEING DIRECTLY
AND THEREFORE NOTHING WOULD BE
ACTUALLY CHANGING
INTRINSICALLY.
JUST WE'D BE LOOKING AT THINGS
AT THE WRONG PLANE.
SO THE IDEA THAT PHYSICS MIGHT
BE CHANGING IS THAT THERE IS NO
SUCH UNCHANGEABLE SUPER LAW,
THAT ACTUALLY THE LAWS
THEMSELVES CHANGE WITHOUT
SOMETHING ABOVE THEM REMAINING
IMMUTABLE.
SO THIS IS QUITE CRAZY, AND AS
I SAID, I'M NOT GOING TO
ACTUALLY BE TALKING ABOUT THIS
AS A PHILOSOPHY THEOREM, I'M
GOING TO BE TALKING ABOUT IT AS
A PHYSICS THEORY, WHICH IS
WHERE VARYING C COMES IN.
SO WHAT I WILL BE DOING OVER
THE NEXT 45 MINUTES OR SO, IS
TAKING YOU ON A TOUR OF THE
CRAZIEST THINGS THAT HAVE BEEN
PROPOSED IN THEORETICAL
PHYSICS.
AND HENCE, THE PERIMETER
INSTITUTE AFFILIATION, THEY
WILL JUST DO CRAZY THINGS, SO
THIS IS ANOTHER ONE.

[Audience laughter]

Joao continues BUT FEAR NOT THAT DOING CRAZY
THINGS MEANS ACTUALLY
UNDERSTANDING THE MAINSTREAM
VERY WELL.
SO I WILL ACTUALLY BE TALKING
ABOUT TEXTBOOK IDEAS, BUT FROM
THE POINT OF VIEW OF TRYING TO
DESTROY THEM.
BUT YOU KNOW, IT'S ACTUALLY THE
BEST WAY TO DESCRIBE THEM
SOMETIMES.
SO WHERE DOES THIS START?

A slide pops up on the projecting screen with the title "The theory of relativity" and the famous picture of Albert Einstein showing his tongue.

Joao continues THIS REALLY STARTS WITH THIS
GUY EVERYONE HAS HEARD OF,
EINSTEIN, OR AT LEAST EVERYONE
RECOGNISES THE HAIRSTYLE,
ATROCIOUS, HUGE TONGUE AS WELL.
AS YOU KNOW, HE'S NOT RENOWNED
FOR THESE TWO ATTRIBUTES, HE'S
RENOWNED FOR INTRODUCING
SOMETHING CALLED THE THEORY OF
RELATIVITY.
EVEN THE I THINK THE THEORY
OF RELATIVITY HAS RECEIVED
TERRIBLE PRESS.
IT IS THE ASSOCIATION MOST
PEOPLE HAVE, AND I'M NOT GOING
TO TALK MUCH MORE ABOUT THIS,
BUT I THINK, WELL NEXT TIME YOU
GO TO A HOSPITAL, LOOK AROUND
YOURSELVES, YOU'RE SURROUNDED
BY PHYSICS EQUIPMENT, WHICH, IN
ONE WAY OR ANOTHER, IS DUE TO
RELATIVITY.
THERE'S ALWAYS GOOD THINGS AND
BAD THINGS IN THE TECHNOLOGICAL
IMPLICATIONS OF ANY THEORY.
IT'S IRONIC, AND EVEN MORE
IRONIC IN THIS CASE, BECAUSE
THE THEORY OF RELATIVITY WAS
INITIALLY PROPOSED AS A NEARLY
PHILOSOPHICAL THING, AS, WHEN I
STARTED, I TALKED ABOUT PHILOSOPHY.
THE THEORY OF RELATIVITY IS
INITIALLY A REFLECTION ABOUT
THE ARENA OF REALITY, WHAT IS
SPACE, WHAT IS TIME, WHERE DO
WE EMBED THINGS?
HOW DO THINGS--
WHAT IS THE FABRIC OF REALITY?
AND THIS IS EXACTLY WHAT IS
BEHIND THE THEORY OF RELATIVITY.

The slide now reads "The speed of light is constant."

Joao continues THE IDEA OF RELATIVISTIC SPACE
AND TIME, IS THAT THE SPEED OF
LIGHT, C, IS A CONSTANT, SO YOU
CAN SEE HOW WE'RE GOING TO HAVE
A PROBLEM WITH THE VARYING
SPEED OF LIGHT.
IT'S LIKE THING NUMBER 1, AND
JUST VERY TOP.
SO THIS IS WHAT I WILL BE
TELLING YOU, AND IF NOTHING
ELSE, THIS IS THE THING I WANT
YOU TO TAKE HOME WITH, IS THE
CONSTANCY OF THE SPEED OF LIGHT
IN MODERN PHYSICS IS NOT JUST
ONE MORE THING TO REMEMBER.
IT'S THE THING TO REMEMBER.
YOU DON'T NEED TO KNOW ANYTHING
ELSE IN PHYSICS, REALLY.

[Audience laughter]

Joao continues SO THE IDEA IS THAT EVERYTHING
IN PHYSICS, HOW YOU MEASURE
THINGS, IS BASED ON THE
YARDSTICK THAT'S THE CONSTANCY
OF THE SPEED OF LIGHT.
HOW YOU CAST THINGS INTO A
FRAMEWORK THAT'S PREDICTABLE,
THAT'S BASED ON THE CONSTANCY
OF THE SPEED OF LIGHT.
SO IT'S THE FACT IN PHYSICS,
IT'S REALLY -- EVEN THE
NOTATION, THE WAY WE WRITE
FORMULAE IN PHYSICS, HAS
EMBEDDED INSIDE IT THE
CONSTANCY OF THE SPEED OF
LIGHT, AND, IN FACT, ONE OF THE
PROBLEMS IN PROPOSING A VARYING
SPEED OF LIGHT, IS WRITING
EQUATIONS IN A WAY THAT'S MORE FLEXIBLE.
SO THERE'S REALLY A LANGUAGE
PROBLEM AS WELL IN PHYSICS.
AND YOU CAN SEE WHY IS IT THAT
PEOPLE THOUGHT I WAS COMPLETELY
OUT OF MY MIND, WHEN WE CAME UP
WITH THIS IDEA THAT PERHAPS THE
SPEED OF LIGHT IS VARIABLE.
SO THIS IS WHAT WE CALL VSL,
VARYING SPEED OF LIGHT.
ME OF MY COLLEAGUES THOUGHT
IT STOOD FOR VERY SILLY INITIALLY.

[Audience laughter]

Joao continues AND THERE'S ACTUALLY A LOT OF
INTERESTING SOCIOLOGY.
I LIKE-- I'M PARTICULARLY VERY
FOND OF THESE...
JOURNALISTS WHO DESCRIBE US AS
THE PUNK ROCKERS OF PHYSICS.
SO I THOUGHT THIS WAS ACTUALLY
APPROPRIATE.

The slide changes to the cover picture of the Sex Pistols single album "Anarchy in the U.K.," featuring a teared Union Jack.

[Audience laughter]

Joao continues THE THEORY WAS INITIALLY
PROPOSED IN THE UNITED KINGDOM,
SO THE SEX PISTOLS ARE
APPROPRIATE HERE.
THERE'S ACTUALLY SOME CANADIAN
PUNK AS WELL, THE IDEA
INITIALLY CAME FROM ALSO,
UNIVERSITY OF TORONTO, JOHN
MOFFATT WAS ONE OF THE PIONEERS
IN THESE IDEAS.
AND WHAT I WILL TRY TO TELL YOU
IS, THIS IS NOT REALLY PUNK
PHYSICS.
THERE IS A LOT OF VERY SERIOUS
REASONS FOR COMING UP WITH
SOMETHING WHICH IS UNDOUBTEDLY
COMPLETELY MAD.
THE PEDIGREE OF THE IDEA
HOWEVER, IS REALLY QUITE
RESPECTABLE, AND IT GOES BACK
TO CAMBRIDGE, ST. JOHN'S
COLLEGE, AS YOU CAN SEE, IT
RAINS A LOT, THERE'S NOTHING
ELSE TO DO BUT THINK OF NEW
THEORIES OF THE UNIVERSE.

A picture shows the college on a cloudy day.

[Audience laughter]

Joao continues AND I WAS ACTUALLY IN THIS
PLACE FOR A WHILE, BUT THE
PERSON I HAVE IN MIND HERE IS
PAUL DIRAC, WHO, IN 1930, HERE,
CAME UP WITH BASICALLY THE
PLACE WHERE VARYING SPEED OF
LIGHT THEORIES COMES FROM.
THIS IS REALLY THE ORIGIN
HISTORICALLY OF VARYING SPEED
OF LIGHT THEORIES.
DIRAC IS AN AMAZING CHARACTER.
HE'S THIS KIND OF PEOPLE WHO IS
LOVED AND REVERED BY ALL THE
PHYSICISTS.
NO ONE ELSE REALLY KNOWS ABOUT
HIM.
AND OKAY, I KNOW HIS HAIRSTYLE
IS NOT AS ECCENTRIC AS
EINSTEIN'S BUT ACTUALLY I THINK
HE'S A MORE INTERESTING
PERSONALITY, AND THERE SHOULD
BE SOME STUDIES ABOUT HIM AT
SOME POINT.
THE REASON THAT WE DON'T KNOW
MUCH ABOUT HIM IS THAT HE WAS
REALLY BORDERLINE AUTISTIC.
HE WAS ONE OF THESE PEOPLE WHO
DIDN'T TALK AT ALL, HE WAS, I
MEAN IT'S THIS KIND OF
BORDERLINE BETWEEN BEING IN A
PSYCHIATRIC HOSPITAL AND
GETTING A NOBEL PRIZE.
THERE'S SOMETHING IN BETWEEN.

[Audience laughter]

Joao continues HE DIDN'T TALK VERY MUCH, HE
WAS AN INCREDIBLE PERSON.
THE REASON WHY YOU WOULD LOVE
HIM, IS, WELL HE CAME UP WITH
THE IDEAS OF ANTIMATTER, FOR
INSTANCE.
HE UNIFIED RELATIVITY AND
QUANTUM MECHANICS, SPECIAL
RELATIVITY AND QUANTUM
MECHANICS.
HE REALLY GAVE US A LOT OF...
AT LEAST AS MUCH AS EINSTEIN, I
WOULD ARGUE, OF MODERN PHYSICS.
BUT FOR THE PURPOSE OF THIS
TALK, HE REALLY INTRODUCED THE
IDEA OF VARYING CONSTANTS.
IN A PAPER HE WROTE IN 1930,
AND I'M GOING TO READ A BIT
FROM THIS PAPER, BECAUSE I
THINK-- I'M GOING TO COMMENT ON
IT, BECAUSE I THINK IT'S VERY
TELLING.
IT'S A VERY STRANGE PAPER.
HE WROTE THIS PAPER WHILE HE
WAS ON A HONEYMOON, WHICH IS...

[Audience laughter]

Joao continues I MEAN, EXPLAIN-- I DON'T KNOW
WHAT HIS WIFE THOUGHT ABOUT
THIS, BUT...
BUT LET ME READ WHAT HE SAID AT
THE TIME.
HE SAID, "ONE FIELD OF WORK IN
WHICH THERE HAS BEEN TOO MUCH
SPECULATION, IS COSMOLOGY."
WE'LL TALK ABOUT COSMOLOGY IN A
BIT.
"THERE ARE VERY FEW HARD FACTS
TO GO ON, BUT THEORETICAL
WORKERS HAVE BEEN BUSY
CONSTRUCTING VARIOUS
MODELS FOR THE UNIVERSE, BASED
ON ANY ASSUMPTIONS THAT THEY
FANCY."
IT IS VERY ENGLISH, FANCY.
"THESE MODELS ARE PROBABLY ALL WRONG."

[Audience laughter]

Joao continues IT'S A FUNNY THING, HE DIDN'T
TALK VERY MUCH, BUT HE OFFENDED
EVERYONE WHENEVER HE SAID ANYTHING.

[Audience laughter]

Joao continues "IT IS USUALLY ASSUMED THAT THE
LAWS OF NATURE HAVE ALWAYS BEEN
THE SAME AS THEY ARE NOW."
THE MAN IS CHANGING LAWS, YOU
CAN SEE THIS COMING.
"THERE IS NO JUSTIFICATION FOR THIS.
THE LAWS MAY BE CHANGING, AND
IN PARTICULAR QUANTITIES WHICH
ARE CONSIDERED TO BE CONSTANTS
OF NATURE...
FOR EXAMPLE, THE SPEED OF
LIGHT...
"MAY BE VARYING WITH
COSMOLOGICAL TIME.
SUCH VARIATIONS WOULD
COMPLETELY UPSET THE MODEL
MAKERS."
IT'S AN INCREDIBLE CITATION.
I LIKE THIS VERY MUCH.
AND THE IDEA IS THAT THERE IS A
MASSIVE EXTRAPOLATION GOING
FROM PHYSICS, WE MEASURE HERE,
AND NOW IN THE LABORATORY, AND
THE BIG BANG, THE BEGINNING OF
THE UNIVERSE.
WE DON'T KNOW WHAT HAPPENED
THERE.
WE DON'T HAVE A LABORATORY
THERE.
SO MAYBE THE LAWS WERE
CHANGING, MAYBE THINGS WERE
COMPLETELY DIFFERENT.
THERE IS REALLY A LOT OF
ASSUMPTIONS HERE, WHICH SHOULD
BE QUESTIONED.
AND I NOTE ONE THING HERE,
ACTUALLY, CHANGING CONSTANTS
DOESN'T MEAN CHANGING LAWS.
AS WE WILL SEE LATER, IT IS
ACTUALLY PUTTING THE FINGER ON
SOMETHING WHICH IS REALLY QUITE
FUNDAMENTAL, WHICH IS MORE THAN
CHANGING CONSTANTS, IT'S
ACTUALLY CHANGING LAWS.
SO ANYWAY, IT'S VERY IMPORTANT
TO SEE WHERE THIS COMES FROM.
I'M JUST GOING TO USE A
FORMULA.
I KNOW I SHOULDN'T HAVE
FORMULAE HERE, BUT ANYWAY, THIS
IS IMPORTANT.
THE REASON WHY HE CAME UP WITH
THIS IDEA IS THE FOLLOWING.
AT THE TIME, PEOPLE WERE
WORRIED ABOUT THIS OTHER
QUESTION, WHERE DO CONSTANTS OF
NATURE TAKE THEIR VALUES?

The Fine Structure Constant pops up on the slide. It reads "Alpha equals the elementary charge squared, divided by the reduced Planck constant times the speed of light."

Joao continues IN OTHER WORDS, WHY IS IT THAT
THE SPEED OF LIGHT IS WHAT IT IS?
WHY IS IT THAT THE MASS OF THE
ELECTRON IS WHAT IT IS, ETC, ETC.
SO JUST TO GIVE YOU AN EXAMPLE,
IF YOU TAKE THE SPEED OF LIGHT,
PLANCK'S CONSTANT, THE ELECTRIC
CHARGE, AND YOU COME UP WITH
THIS COMBINATION, YOU SEE
SOMETHING THAT WILL COME IN
LATER IN THE TALK, IT'S
SOMETHING CALLED ALPHA, OR THE
FINE STRUCTURE CONSTANT, WHICH
IS OBSERVED IN THE LABORATORY
TO BE APPROXIMATELY 1 OVER 137.
SO THE QUESTION IS, WHY 137?
WHAT'S THE REASON FOR THIS?
SO WE DO KNOW WHY IS IT THAT PI
IS WHAT IT IS.
PI IS 3.14, ETC, FOR A GOOD
GEOMETRICAL REASON.
THERE'S A SERIES OF
MATHEMATICAL SERIES WHICH GIVES
3.14 ETC.
SO HEISENBERG WAS THE FIRST ONE
TO COME UP WITH THIS IDEA THAT
PERHAPS FOR THE SAME REASON WE
KNOW WHY PI IS WHAT IT IS, WE
WOULD KNOW WHY ALPHA IS WHAT IT
IS, ETC, ETC.
AND HEISENBERG WAS THE GUY WHO
PROPOSED ACTUALLY THIS
COINCIDENCE.
ACTUALLY, ALPHA IS
APPROXIMATELY PI OVER THIS
COMBINATION OF NUMBERS.
SO THIS IS NOT VERY
SATISFACTORY.
THIS IS THE REASON WHY DIRAC
WAS A BIT ANNOYED.
HE'S A BIT LIKE YOU KNOW, BLACK
MAGIC, IT'S A COINCIDENCE, IT'S
NUMEROLOGY.
HE BECAME EVEN MORE ANNOYED
WHEN PEOPLE IMPROVED ON THIS
NUMBER, AND HEISENBERG CAME UP
WITH HIS FORMULA.

[Audience laughter]

Joao continues SO THIS HAS ALL THE SYMPTOMS OF
A BAD IDEA.
THIS IS CLEARLY SOMETHING...
I MEAN A GOOD IDEA, THINGS GET
MORE COMPLICATED AND THE IDEA
STAYS SIMPLE.
THIS IS RIDICULOUS, I THINK.
SO THE IDEA OF DIRAC WAS THAT
MAYBE ONE EXPLANATION IS
PRECISELY THAT THEY'RE NOT
CONSTANT.
THE CONSTANTS OF NATURE, MAYBE
WHAT THEY ARE IS FIELDS, WHICH
ARE VERY RIGID, THEY SOAK UP A
LOT OF ENERGY TO VARY IN SPACE
AND TO VARY IN TIME, AND
THEREFORE THEY GIVE THE
IMPRESSION THAT THEY'RE
CONSTANTS, BUT THEY'RE ONLY
CONSTANT BECAUSE WE LIVE IN A
VERY BORING ENVIRONMENT IN A
VERY COLD UNIVERSE.
IF YOU GO NEAR THE BIG BANG,
AND YOU CAN SOAK UP ALL THE
ENERGY IN THE BIG BANG, OR IF
YOU GO NEAR A BLACK HOLE, THEN
THE FLUIDITY OF THESE FIELDS
WILL BECOME APPARENT AND IN
FACT YOU WILL SEE THAT THESE
CONSTANTS ARE ACTUALLY VARIABLE.
SO THE IDEA OF DIRAC IS THAT--
THEN THE QUESTION IS WHY THINGS
CRYSTALLISED WHERE THEY DID.
THAT'S A COMPLETELY DIFFERENT
PERSPECTIVE WHEN TRYING TO FIND
OUR ARCANE FUNDAMENTAL REASONS,
LIKE RELATING PI WITH ALPHA,
ETC, ETC.
AND THIS REALLY CHANGES THE
PERSPECTIVE.
I MEAN PHYSICISTS ARE
INCREDIBLY OBSESSIVE PEOPLE.
I DON'T KNOW IF YOU'VE NOTICED
THIS.
BUT AN EXAMPLE IS THIS GUY,
WOLFGANG PAULEY, WHO WAS
COMPLETELY OBSESSED WITH THE
IDEA OF WHY 137.

A black and white picture shows a pensive balding man in his fifties smoking a pipe. Several numbers 137 appear on his face.

Joao continues HE SPENT ALL HIS LIFE TRYING TO
UNDERSTAND THIS NUMBER, TO THE
POINT THAT, WHEN HE WAS TAKEN
TO HOSPITAL TO DIE OF HIS
TERMINAL DISEASE, HE ACTUALLY
INSISTED ON BEING PUT IN ROOM NUMBER 137.

[Audience laughter]

Joao continues WHICH IS AN EXAGGERATION OF THE
OBSESSION, AND YOU SEE, FROM
DIRAC'S PERSPECTIVE, THERE IS
NOTHING PARTICULARLY SPECIFIC
ABOUT 137, JUST WAIT ANOTHER 10
BILLION YEARS, AND YOU'LL BE
ASKING FOR ROOM 138.
THERE IS NOTHING REALLY SPECIAL
ABOUT 137.
SO THIS IS THE BACKGROUND, THIS
IS WHERE WE CAME FROM.
NOW THIS IS LIKE, FOR
PHYSICISTS -- YOU KNOW, IF
YOU'RE NOT A PHYSICIST, IT'S A
BIT -- I HAVE A FEW SLIDES THAT
SHOW A BIT MORE ADVANCED, BUT
THE IMPORTANT THING HERE IS TO
RECOGNISE THAT IF YOU GO FOR
VARYING CONSTANTS, THERE'S
QUITE A BIG DIFFERENCE BETWEEN
WHICH VARYING CONSTANT.
SO SOME CONSTANTS ARE REALLY
STRUCTURAL, LIKE THE SPEED OF LIGHT.
IF YOU'RE A PHYSICIST, YOU
RECOGNISE A FEW OTHERS.
SO THEIR STRUCTURAL BECAUSE
THEIR USE BUILDS UP THE WHOLE
OF PHYSICS.
NOW THERE ARE OTHER KINDS OF
CONSTANTS LIKE NEWTON'S G, IS
LIKE THE STRENGTH OF GRAVITY.
OTHER THINGS ARE LIKE THE
MASSES OF ELEMENTARY PARTICLES.
THAT'S WHAT I CALL DESCRIPTIVE,
ETC, ETC.

Three mathematical expressions pop up that read "Structural, Interaction strengths, and descriptive.

Joao continues THERE'S ALL
KINDS OF DIFFERENT TYPES OF
CONSTANTS AND WHENEVER YOU TALK
ABOUT VARYING CONSTANTS, YOU
SHOULD NEVER GENERALISE.
SO IF YOU'RE A
PHYSICIST, YOU CAN CERTAINLY
RECOGNISE THAT THESE THINGS
PLAY VERY DIFFERENT ROLES.
SO HISTORICALLY IT'S NOT
SURPRISING THAT VARYING
CONSTANT THEORIES, UNTIL QUITE
RECENTLY, WERE MAINLY VARYING
NEWTON'S CONSTANT AND VARYING
ELECTRICAL CHARGE THEORIES.
THAT'S REALLY THE KIND OF THING
WHICH DIRAC HAD IN MIND.

Now on the slide the letter "e" for the elementary charge appears with the caption "Bekenstein, 1982" and the letter "G" appears with the caption "Brans-Dicke, 1961.)

Joao continues NOT EVEN DIRAC WAS THIS CRAZY
TO CONSIDER A VARYING AND A
VARYING PLANCK'S CONSTANT,
BECAUSE WHAT YOU'RE DOING
REALLY THEN IS ASKING, ARE WE
GOING TO MESS UP WITH THE WHOLE
OF PHYSICS?
WHAT HAPPENS IF THE VARYING
CONSTANT WE HAVE IN MIND IS
ACTUALLY THE SPEED OF LIGHT.
SO WHAT ARE YOU DOING, REALLY
GOES BACK TO THIS GUY, ALBERT
EINSTEIN, THIS
[Inaudible]
WHO, IN 1905, CHANGED THE
FOUNDATIONS OF PHYSICS TO MAKE
C THE BIG FOUNDATION.
AND THAT'S WHAT I'M GOING TO
TELL YOU ABOUT IN THE NEXT 5
MINUTES.
WHAT IS, EXACTLY, RELATIVITY?
WHY IS THE CONSTANT OF C SO
IMPORTANT?
WHY IS IT THAT PHYSICISTS
BECOME HYSTERICAL IF YOU TALK
ABOUT VARYING SPEED OF LIGHT,
AND THEY THINK YOU'RE MAD?
THERE'S ACTUALLY GOOD REASON
FOR IT.
SO THERE'S A TERRIBLE
MISUNDERSTANDING AROUND, I READ
SOMEWHERE THAT ONLY TEN PEOPLE
UNDERSTAND RELATIVITY.
AND IT'S COMPLETELY WRONG.
I THINK ACTUALLY ONLY TEN
PEOPLE DON'T UNDERSTAND
RELATIVITY THESE DAYS, BECAUSE
ACTUALLY, THERE'S A FEW THINGS
I DON'T UNDERSTAND, I HAVE TO
SAY THAT.
AND IT'S ONLY AFTER A CERTAIN
POINT THAT YOU START
UNDERSTANDING WHAT YOU DON'T
UNDERSTAND.
IT'S COMPLICATED, BUT...
BUT IF YOU DON'T TAKE THINGS
TOO DEEPLY, RELATIVITY IS
REALLY A VERY SIMPLE THING.
I DON'T SEE WHY PEOPLE
SHOULDN'T UNDERSTAND.
AND THE CRUCIAL THING, AS I
SAID, THE ONLY THING YOU NEED
TO REMEMBER IS THE CONSTANCY OF
THE SPEED OF LIGHT.
NOW THIS IS A CRAZY CONCEPT,
AND ESSENTIALLY WHAT HE IS
SAYING IS THE FOLLOWING.
SO THIS BEING NORTH AMERICA,
I'M SURE YOU ALL DROVE HERE,
AND YOU KNOW, IF SOME OF YOU
GOT A TRAFFIC JAM -- I DON'T
THINK ANYONE FLEW HERE, BUT
ANYWAY, IT'S A POSSIBILITY.

A new slide shows several drawings of cars.

Joao continues AND ONE THING YOU NOTICED IS
THAT YOUR SPEED IN RESPECT OF
THE OTHER CARS CHANGED WHETHER
YOU ACCELERATED OR YOU BRAKED.
THAT'S WHY YOU ACCELERATED AND
YOU BRAKED.
YOU KNOW, YOU CHANGED THE SPEED
OF YOUR CAR WITH RESPECT TO THE
OTHER CARS.
NOW IMAGINE A CAR WHICH IS A
LIGHT RAY.
THE STATEMENT IN RELATIVITY IS
THAT THE SPEED OF THIS CAR WITH
RESPECT TO YOUR CAR IS THE SAME
REGARDLESS OF WHAT YOU'RE DOING.
REGARDLESS OF WHETHER YOU'RE
STATIONARY, IF YOU'RE MOVING
THIS WAY, THAT WAY, IF YOU
ACCELERATE, IF YOU BRAKE.
IF YOU MEASURE THE SPEED OF
THIS LIGHT RAY, YOU WILL ALWAYS
GET THE SAME THING.
AND THIS IS COMPLETELY MAD.
I MEAN, THIS IS COMPLETELY
CRAZY, AND ALL YOU ARE SAYING
IN A WAY, IMMEDIATELY IS THAT
SOME OF THESE PRECONCEPTIONS
ABOUT WHAT IS SPACE AND TIME
HAS GOT TO BREAK TO ACCOMMODATE
THIS IDEA THAT THE SPEEDS, THE
RELATIVE SPEEDS ARE NOT JUST
ADDITIVE THINGS, BUT ACTUALLY
STAY CONSTANT.
IF YOU HAVE SOMETHING LIKE A
LIGHT RAY.
SO CLEARLY YOU'VE HEARD ABOUT
THE SOLUTION.
THE SOLUTION IS THE FOLLOWING.

A new slide reads "How can the speed of light be the same for everyone?"

Joao continues THE ONLY WAY FOR EVERYONE TO
MEASURE THE SAME SPEED OF
LIGHT, IS FOR TIME AND SPACE TO
BE RELATIVE.
SO IF THE SPEED OF LIGHT IS THE
SAME FOR ALL THESE CARS, THE
WAY TIME AND SPACE IS PERCEIVED
HAS GOT TO BE RELATIVE AND BE
DIFFERENT FOR ALL THESE OTHER CARS.
AND SPECIFICALLY THE CONCLUSION
OF RELATIVITY IS THAT TIME
DILATES FOR MOVING OBSERVERS.
IF YOU HAVE TWO TWINS AND ONE
GOES AUND THE UNIVERSE VERY
FAST, WHEN HE COMES BACK, THE
E THAT STAYED AT HOME IS MUCH
OLDER.
D THINGS CONTRACT IN THE
DIRECTION OF MOTION.
THEY KIND OF SQUEEZE IF THEY'RE
MOVING.
SO TO SOME EXTENT, MOVING CLOSE
TO THE SPEED OF LIGHT IS THE
ULTIMATE HEALTH DIET, IT KEEPS
YOU YOUNG, AND IT SLIMS YOU AS
WELL IN THIS DIRECTION, SO IT'S
TWO THINGS IN ONE.
IT IS BASICALLY WHAT IS INSIDE
RELATIVITY, THESE TWO CONCEPTS.
SO THIS IS ONE THING TO REMEMBER.
THIS IS VERY IMPORTANT LATER ON
FOR VARIOUS THINGS I HAVE TO
TELL YOU.
THE OTHER THING THAT IS VERY
ANNOYING FOR SCIENCE FICTION
FILMS IS, THE SPEED OF LIGHT IS
A SPEED LIMIT.
SO IF THE SPEED OF LIGHT -- IF
THIS RAY DOESN'T CHANGE IT'S
SPEED, REGARDLESS OF WHAT I DO,
I CAN ACCELERATE, I CAN BRAKE,
I CAN DO WHATEVER I WANT, I
WILL NEVER OVERTAKE LIGHT, SO
LIGHT IS A SPEED LIMIT.
AND THIS MEANS THAT REALLY, WE
ARE STUCK IN OUR CORNER OF THE
UNIVERSE.
TO GET OUT OF THE GALAXY WOULD
TAKE A MILLION YEARS PROPERLY,
AND THIS IS REALLY A COMPLETE
DISASTER FOR SCIENCE FICTION,
IF YOU THINK A BIT ABOUT IT.
SO THIS IS, IN A NUTSHELL, WHAT
RELATIVITY HAS TO TELL YOU, AND
THIS HAS BECOME SO INGRAINED IN
ACTUAL -- WHAT PEOPLE KNOW IN
GENERAL, THAT THE GENERAL
RESONANCE BOX OF FACTS PEOPLE
KNOW IT.
THE OTHER DAY-- THE LAST TIME I
HAD A BIRTHDAY, SOMEONE SENT ME
A BIRTHDAY CARD WITH EINSTEIN.
AND THIS IS ONE OF THE MOST
INSULTING BIRTHDAY CARDS I'VE
EVER GOT IN MY LIFE.
UPON OPENING IT, IT YS, "THE
SPEED OF LIGHT MAY BE ABSOLUTE,
BUT AGE IS RELATIVE.
HAVE A GREAT BIRTHDAY."

[Audience laughter]

Joao continues SO THIS IS THE LEVEL, EVERYONE
HAS HEARD OF THIS EFFECT.
THEY'RE ACTUALLY MEASURED IN
LABORATORY, THEY'RE ACCESSIBLE
TO MEASUREMENT IN A LABORATORY.
AND THIS IS BASICALLY WHAT WE
ARE THROWING OUT.
SO THE PUNK ROCKERS, IT MEANS
ESSENTIALLY THROWING OUT THESE
THINGS WHICH, YOU MAY NOT
APPRECIATE IT, YOU KNOW ABOUT
THESE EFFECTS BUT YOU MIGHT NOT
APPRECIATE THIS IS REALLY THE
FOUNDATION OF EVERYTHING IN
PHYSICS.
AND WHAT YOU'RE DOING HERE IS
BASICALLY ASKING THE QUESTION,
IS THIS REALLY DEAD ROCK SOLID?
ARE THERE GOOD REASONS FOR
GIVING THIS UP?
WHY ARE WE DOING THIS?
SO BEFORE ADDRESSING THAT
QUESTION, I ALWAYS LIKE TO PUT
A SOCIOLOGY POINT HERE WHICH IS
NOT WIDELY KNOWN.
BUT I THINK IT'S VERY
IMPORTANT, AND IT'S ESSENTIALLY
THAT THIS GUY HERE, ALBERT
EINSTEIN, WAS ACTUALLY THE
FIRST PERSON TO PROPOSE A
VARYING SPEED OF LIGHT THEORY.
IN 1911, THIS IS NOT WIDELY
KNOWN, AND HE DID IT FOR
REASONS FOR WHICH, MEANWHILE,
YOU KNOW, HE CHANGED HIS MIND,
BUT THE POINT REMAINS THAT THE
MAN WHO INVENTED WHAT IS NOW A
DOGMA, WASN'T DOGMATIC ABOUT IT
HIMSELF.
HE WAS THE FIRST PERSON WHO WAS
READY TO GIVE UP THE CONSTANCY
OF THE SPEED OF LIGHT, IF YOU
COULD SEE A GOOD REASON FOR
DOING IT.
SO THIS 1911 THEORY IS
IRRELEVANT FOR THE REST OF THE
TALK, BUT DOES MAKE THIS POINT,
IF YOU HAVE GOOD REASONS IN
PHYSICS FOR GIVING UP WHAT YOU
THINK IS A GOOD STRONG
FOUNDATIONAL PRINCIPLE, YOU
SHOULD.
THIS IS BASICALLY THE MESSAGE
YOU TAKE FROM THIS.
OF COURSE THERE ARE MANY JOKES
ABOUT THIS, COMPLETELY
INAPPROPRIATE, EINSTEIN WAS IN
PRAGUE AT THE TIME, AND PEOPLE
HAVE MADE COMMENTS ABOUT THE
LIFESTYLE HE HAD IN PRAGUE,
WHICH WAS COMPLETELY, YOU KNOW,
ANYWAY, BUT HE DID ACTUALLY
COME UP WITH THESE PAPERS,
WHICH I THINK ARE VERY
IMPORTANT.
SO FOR THE REST OF THIS TALK,
THIS IS BASICALLY WHAT I'M
GOING TO BE TELLING YOU.
I'M GOING TO BE INTRODUCING THE
MAIN REASONS FOR PROPOSING A
VARYING SPEED OF LIGHT THEORY.
WHAT, EXACTLY MOTIVATED US, AND
I'LL TELL YOU ABOUT TWO THINGS.
WHEN IT'S COSMOLOGY, IT'S
ESSENTIALLY THE REASON WHY
INITIALLY THE IDEA WAS
PROPOSED.
MORE RECENTLY, IS THIS SEARCH
FOR THE GRAND UNIFIED THEORY,
I'LL BRIEFLY TELL YOU ABOUT
WHAT IS A GRAND UNIFIED THEORY,
WHY WE ARE TRYING TO UNIFY
EVERYTHING, WHY PEOPLE AT THE
PERIMETER INSTITUTE ARE GOING
COMPLETELY CRAZY ABOUT THESE,
AND WASTING THEIR TIME ON
THINGS THAT WILL NEVER GO
ANYWHERE, OR MAYBE THEY WILL,
WE DON'T KNOW.
THERE IS A CONNECTION BETWEEN
THESE TWO THINGS.
AND THEN FINALLY, I'LL TELL YOU
WHY THERE IS ACTUALLY SOME
OBSERVATIONAL EVIDENCE FOR A
VARYING SPEED OF LIGHT.
SO THESE ARE THE THREE THINGS I
WANT TO TELL YOU.
AND THEN I MAY FINISH WITH SOME
PHILOSOPHICAL DISCUSSION ON
WHAT IS VARIABILITY OF THE LAWS
OF NATURE, AND WHY IS IT THAT
IT'S BEST TO CAST THIS
PHILOSOPHICAL CONCEPT IN THE
FRAMEWORK OF A VARYING C.
IT'S VERY EASY TO WAFFLE AND
WAFFLE AND WAFFLE ABOUT VARYING
LAWS, BUT YOU NEED SOME
FRAMEWORK, FOR THINGS
ESPECIALLY TO BE MEANINGFUL,
AND I THINK A VARYING C IS A
GOOD EXAMPLE OF THAT.
OKAY, SO LET ME TELL YOU A BIT
ABOUT COSMOLOGY.
THIS IS WHAT I NORMALLY WRITE
AS A JOB DESCRIPTION ON VISA
APPLICATIONS AND WHEN I GO
THROUGH PASSPORTS-- THROUGH
AIRPORTS AND THINGS LIKE THAT.
PEOPLE ALWAYS LOOK AT ME VERY
STRANGELY.
COSMOLOGIST, WHAT IS THAT?
IS IT A PRIEST, IS IT AN
ASTROLOGER, WHAT IS IT?

[Audience laughter]

Joao continues AND IT IS INDEED A STRANGE
CONCEPT.
WHEN YOU-- I HADN'T APPRECIATED
THIS UNTIL RECENTLY, BUT YOU'RE
ASKING MOMENTOUS QUESTIONS.
YOU'RE ASKING...

A new slide pops up with the title "Cosmology: the Universe as a natural phenomenon."
The slide reads "Where did the universe come from? How big is the world? How old is the world? Will there be an end for the universe?"

Joao continues SO THEY'RE REALLY QUITE DEEP
QUESTIONS, WHICH USED TO BE THE
PRESERVE OF THEOLOGY, AND WHICH
NOW WE'RE SAYING, THIS IS A
BUNCH OF PHYSICS.
SO WHENEVER NOW I SAY, I'M A
PHYSICIST, PEOPLE THINK I'M
LYING, BECAUSE AT THIS POINT,
YOU KNOW, WHY DOES A PHYSICIST
BUILD BRIDGES?
THAT'S COMPLETELY DIFFERENT
FROM ADDRESSING THESE QUESTIONS.
BUT THE IDEA BEHIND COSMOLOGY
IS THAT THE PHYSICS BEHIND
BUILDING A BRIDGE AND THE
PHYSICS BEHIND ADDRESSING THESE
QUESTIONS IS EXACTLY THE SAME.
AND YOU SHOULD USE THE SAME
TOOLS FOR ADDRESSING THESE QUESTIONS.
SO COSMOLOGY IS ACTUALLY AN
EXPERIMENTAL SCIENCE.
NOT THAT WE CAN REPEAT THE
EXPERIMENT, OBVIOUSLY.
WE CANNOT GO AND PRODUCE A
UNIVERSE IN A LABORATORY, BUT
THE IDEA IS THAT YOU CAN LOOK
AT THE END PRODUCT WITH A
TELESCOPE.
AND THIS IS WHAT THIS GUY DID.
THIS GUY IS CALLED EDWIN HUBBLE.
HE IS A VERY IMPORTANT
INFLUENTIAL COSMOLOGIST, HE IS
THE FIRST COSMOLOGIST.
HE IS THE GUY WHO OPENED UP THE
IDEA THAT THE UNIVERSE IS MADE
OF GALAXIES A MUCH BIGGER THING
THAN WHAT WE THOUGHT.
FUNNILY ENOUGH, HE WAS A LAWYER.
HE GAVE UP HIS JOB.
I THINK HE HAD PERSONAL MONEY,
SO HE DIDN'T CARE ABOUT IT
ANYWAY, BUT HE FOUND THAT IT
WAS MUCH MORE INTERESTING TO
LOOK AT THE SKY.
AND WHAT HE DISCOVERED WAS
SOMETHING COMPLETELY CRAZY.
HE DISCOVERED THAT, IF YOU LOOK
AT THE UNIVERSE WITH THE RIGHT
TECHNIQUES, THAT THE UNIVERSE
IS BIGGER THAN WHAT WE THINK,
IT'S NOT MADE OF STARS, IT'S
MADE OF MUCH BIGGER THINGS
CALLED GALAXIES, AND WHAT
ACTUALLY HAPPENS IS THE
UNIVERSE IS EXPANDING.
SO WHAT HE DISCOVERED IS THAT
THE GALAXIES ARE RECEDING AWAY
FROM EACH OTHER.

A new slide reads "The Universe is expanding! The universe came out of a BIG BANG."

Joao continues NOW THERE'S A LOT OF
MISUNDERSTANDINGS ABOUT THIS.
THE EXPANSION OF THE UNIVERSE
IS REALLY NOT A REAL MOVEMENT.
SO IT'S MORE LIKE SPACE IS
BEING CREATED BETWEEN THINGS.
THE EXPANSION OF THE UNIVERSE
IS NOT THE MOVEMENT OF GALAXIES
RECEDING AWAY FROM EACH OTHER,
IT IS THE CREATION OF SPACE IN
BETWEEN THE GALAXIES.
IT'S A BIT LIKE, YOU HAVE A
CITY, YOU BUILD THINGS, SPACE
APPEARS BETWEEN THE BUILDINGS.
SO YOU BUILD A PARK, SPACE
APPEARS.
YOU BUILD MORE, AND MORE
BUILDINGS, AND MORE AND MORE
SPACE APPEARS.
SO IT'S LIKE EVERY URBAN
ARCHITECT'S DREAM.
THIS IS SOMETHING THAT GOES ON
FOREVER.
IT'S LIKE A CREATION OF SPACE,
AND THAT'S WHAT IS HAPPENING
INSIDE THE UNIVERSE WHEN WE SAY
THE UNIVERSE IS EXPANDING.
AND YOU SHOULD THINK OF IT THAT
WAY, RATHER THAN THE IDEA OF
SOMETHING MOVING, THE GALAXIES
MOVING.
BUT WHAT REALLY COMES OUT OF
THIS IS, IF YOU REWIND THE
FILM, AND YOU NOW ASK, OKAY, IF
SPACE IS BEING CREATED, WAS
THERE A TIME IN THE PAST WHEN
THERE WAS NO SPACE BETWEEN
THINGS AT ALL?
WHEN ALL THE SPACE HAD BEEN
REMOVED.
AND THE ANSWER IS YES.
IF YOU REWIND THE FILM,
SOMETIME BETWEEN 10 AND 15
BILLION YEARS AGO, EVERYTHING
WAS IN ONE SINGLE POINT, AND
THERE WAS ACTUALLY NO SPACE IN
BETWEEN ANYTHING IN THE UNIVERSE.
AND THIS IS COMPLETELY CRAZY,
BUT THIS IS BASICALLY WHAT
COMES OUT OF WHAT WE CALL
NOWADAYS, BIG BANG COSMOLOGY.
NOW BIG BANG COSMOLOGY IS VERY
SUCCESSFUL BUT IT'S NOT A BED
OF ROSES.
THERE ARE A LOT OF PROBLEMS AND
WHEN I WAS IN GRAD SCHOOL, WE
WERE TOLD ABOUT ALL THESE
SUCCESSES, BUT WE WERE GIVEN
LIKE, HOMEWORK, PROBLEM SOLVED,
GO AND INVENT A NEW THEORY, AND
SOLVE THESE PROBLEMS OF THE BIG
BANG.
AND LET ME TELL YOU THE
SIMPLEST ONE.
IT'S LIKE, ABOUT SEVEN OR
EIGHT, WHICH ARE, LIKE, CLASSIC
STAPLES OF PROBLEMS OF THE BIG
BANG THEORY.
I MEAN THE MOST OBVIOUS ONE IS,
WHERE DO THINGS COME FROM?
IF THINGS WERE IN A POINT, WHAT
HAPPENED BEFORE?
IT'S THE MOST OBVIOUS ONE, BUT
ANOTHER -- AN EXAMPLE OF
SOMETHING ELSE, IS SOMETHING
WHICH WE CALL THE HORIZON
PROBLEM, WHICH I SELECTED, NOT
BECAUSE IT'S THE MOST
COMPLICATED PROBLEM, BUT
BECAUSE IT'S PROBABLY THE
EASIEST ONE TO RELATE WITH THE
VARYING C.
SO THE IDEA IS THE FOLLOWING.
I TOLD YOU TWO THINGS NOW.
I TOLD YOU THAT ACCORDING TO
RELATIVITY...

He reads from a new slide and says
The speed of light is the speed limit.

He continues AND I TOLD YOU ONE THING
JUST NOW, I TOLD YOU THAT...
THERE'S A FINITE TIME BETWEEN
THE MOMENT OF CREATION, THE BIG
BANG, AND NOWADAYS, 10 BILLION
YEARS, SAY.
SO IMMEDIATELY YOU FIND THE
FOLLOWING CONCLUSION, WHICH IS
THAT...
Any form of contact has a limited range of action. There is a horizon.
SO IF THE SPEED LIMIT ON A
GIVEN HIGHWAY IS 100 KILOMETRES
PER HOUR, AND I HAVE ONE HOUR,
AND IF I STICK TO THE SPEED
LIMIT OF COURSE, I CANNOT GO
BEYOND 100 KILOMETRES IN ONE HOUR.
SO LIKEWISE IN A UNIVERSE WHICH
IS 10 BILLION YEARS OLD, THERE
MUST BE SOME KIND OF HORIZON,
SOME KIND OF REGION BEYOND
WHICH I CANNOT TRAVEL, I CANNOT
PROPAGATE, I CANNOT GET
INFORMATION ACROSS, WHICH IS
THE DISTANCE THE LIGHT WOULD
HAVE COVERED, WHICH IS 10
BILLION LIGHT YEARS.
SO THIS IS SOMETHING WHICH WE
CALL THE HORIZON EFFECT IN THE
BIG BANG UNIVERSE, AND
IMMEDIATELY THE PROBLEM IS THAT
THE HORIZON GETS VERY SMALL, AS
WE GO BACKWARDS IN TIME.
SO WHEN THE UNIVERSE IS VERY,
VERY YOUNG, THE DISTANCE THAT
INFORMATION CAN HAVE TRAVELLED
IS VERY, VERY SMALL.
BECAUSE THE SPEED OF LIGHT IS
STILL THE SPEED LIMIT, AND NOW
WE HAVE LESS AND LESS TIME.
SO WE END UP WITH THIS PICTURE
THAT THE EARLY UNIVERSE, THE
BABY UNIVERSE IS COMPLETELY
FRAGMENTED INTO COMPLETELY
DISCONNECTED REGIONS, WHICH WE
CALL THE HORIZONS.
THIS IS VERY SERIOUS AS A
PROBLEM, BECAUSE THEN, AS
PHYSICISTS WE HAVE TO EXPLAIN
WHY IS IT THAT THE UNIVERSE IS
THE SAME EVERYWHERE WE LOOK?
THE SAME RADIATION, THE SAME
GALAXIES, THE SAME PROPERTIES
EVERYWHERE WE GO.
WELL NORMALLY THINGS BECOME THE
SAME BY COMING INTO CONTACT
WITH EACH OTHER.
SO I HAVE HOT THINGS, COLD
THINGS, I BRING THEM TOGETHER,
SAME TEMPERATURE.
MILK AND COFFEE, I STIR IT,
MILK AND COFFEE, ETC, ETC.
I WOULD LIKE TO HAVE A SIMILAR
REASON FOR WHY THE UNIVERSE IS
SO HOMOGENEOUS, SO THE SAME
EVERYWHERE.
AND WHAT YOU ARE SAYING WITH
THE HORIZON PROBLEM, IS THAT
BECAUSE I HAVE THIS
FRAGMENTATION OF THE UNIVERSE,
OF THE REGIONS WHICH ARE
COMPLETELY OBLIVIOUS OF THE
REST OF THE UNIVERSE, I CANNOT
HAVE SUCH AN EQUILIBRATION
MECHANISM, BECAUSE I DON'T HAVE
CONTACT BETWEEN THINGS.
SO THIS IS REALLY, AT THE
SIMPLEST WAY, THIS IS REALLY
WHERE THE VARYING SPEED OF
LIGHT THEORY COMES FROM.
SO I VERY MUCH LIKE THIS
STATEMENT BY LYNDALL,
"COSMOLOGISTS ARE OFTEN WRONG,
BUT SELDOM IN DOUBT."
IT'S A GREAT QUOTE, AND I THINK
IT'S TRUE.
PEOPLE -- THIS GOES ALSO BACK
TO DIRAC'S HONEYMOON PAPER,
WHERE HE ACTUALLY QUESTIONED
ABOUT HOW CERTAIN COSMOLOGISTS
ARE ABOUT EVERYTHING ALL THE
TIME.
SO THEY GET INTO PROBLEMS
BECAUSE THEY ASSUME TOO MUCH.
AND THEN THEY GET STUCK AND
THEY JUST CONTINUE TO ASSUME
TOO MUCH.
AND I THINK IT'S COMPLETELY
OBVIOUS THAT ONE WAY TO SOLVE
THIS PROBLEM IS PRECISELY TO
RAISE THE SPEED LIMIT IN THE
EARLY UNIVERSE.
THIS IS THE MOST NAIVE THING TO
DO, INDEED, THERE'S NOTHING
PARTICULARLY INTELLIGENT ABOUT
THIS.
THE DIFFICULT THING IS NOT TO
COME ACROSS WITH SOMETHING
WHICH IS A THEORY WHICH HAS THE
VARYING SPEED OF LIGHT, AND
WHICH EXPLAINS THE HORIZON
PROBLEM.
SO THIS IS ESSENTIALLY WHERE
THE VARYING C CAME FROM
INITIALLY.
IT WAS BASICALLY THIS KIND OF
INSIGHT ABOUT YOU KNOW, SOLVING
THE HORIZON PROBLEM JUST BY
ALLOWING THINGS TO TRAVEL
FASTER IN THE EARLY UNIVERSE,
VERY MUCH FASTER THAN NOWADAYS.
THE THING WHICH HAS BEEN VERY
DIFFICULT OVER THE PAST TEN
YEARS OR SO, IS DO THIS
CONSISTENTLY AND COME UP WITH
SOMETHING WHICH IS AS SOLID AS
RELATIVITY BUT WHICH CONTAINS
THIS FEATURE.
SO THIS IS ONE ASPECT OF THE
STORY.
LET ME TELL YOU ABOUT THE OTHER
TWO.
WELL THE SECOND ONE IS REALLY
QUITE A TOUGH ONE.
THE SECOND ONE HAS GOT TO DO
WITH UNIFICATION.
AND THIS IS ONE THING WHICH YOU
MAY HAVE HEARD -- THIS IS ONE
THING PHYSICISTS, THEORETICAL
PHYSICISTS ARE ALL TRYING TO DO
THESE DAYS.
THEY'RE TRYING TO DO SOMETHING
WHICH IS TO BRING TOGETHER LOTS
OF THEORIES INTO A SINGLE
THEORY, SO ELECTRICITY,
MAGNETISM, NUCLEAR FORCES,
GRAVITY.
THE IDEA IS THAT AT THE MOMENT
WE HAVE ALL THESE DIFFERENT
THEORIES.
IT'S LIKE DIFFERENT POLITICAL
PARTIES OR WHATEVER.
THERE'S VERY DIFFERENT WAYS OF
DESCRIBING DIFFERENT ASPECTS OF
NATURE, AND WHAT YOU'D LIKE TO
DO IS TO HAVE ONE THING WHICH
UNIFIES ALL THESE DIFFERENT
THEORIES.
SO THIS IS ACTUALLY WIDELY
KNOWN BECAUSE OF THIS PICTURE.

A black and white picture shows an office with a messy desk covered in papers and a chalkboard with several notes on it.

Joao continues THIS IS EINSTEIN'S OFFICE, AS
HE LEFT IT JUST BEFORE HE DIED,
AND THIS WAS THE THING HE WAS
TRYING TO FIND OUT AT THE TIME.
SO THE IDEA OF
A GRAND-UNIFIED THEORY,
SOMETHING WHICH WOULD BRING
TOGETHER GRAVITY, LIGHT,
ELECTRICITY, MAGNETISM, ETC, IS
THE THING HE TRIED TO DO UNTIL
THE END, AND WHICH HE FAILED
COMPLETELY.
WE HAVEN'T DONE MUCH BETTER,
AND I FOUND MYSELF STUPIDLY
TRYING TO READ WHAT HE WAS
ACTUALLY WRITING.
MAYBE THERE
WAS A SOLUTION THERE.

[Audience laughter]

Joao continues THERE ISN'T, AND IF YOU GO TO
PERIMETER, YOU FIND PEOPLE
WORKING ON THIS VERY HARD.
THERE'S DIFFERENT APPROACHES,
STRING THEORY, LOOP QUANTUM
GRAVITY, THESE VARIOUS THINGS.
TO BE FAIR WITH YOU, THIS HAS
BEEN 100 percent FAILURE RATE.
WE HAVEN'T SUCCEEDED AT ALL IN
SOLVING THIS PROBLEM.
IT'S ACTUALLY A CURIOUS THING.
WHEN I WAS IN CAMBRIDGE, PEOPLE
HAD THIS TERRIBLE HABIT OF
SETTING EXAM QUESTIONS WHICH
WERE PROBLEMS NO ONE COULD SOLVE.

[Audience laughter]

Joao continues THIS IS CRAZY, AND IT'S
COMPLETELY--
OF COURSE PEOPLE FAILED THE
EXAMS AND THINGS LIKE THAT, BUT
AMAZINGLY ENOUGH, THERE'S
ACTUALLY INSTANCES IN THE PAST
WHERE PEOPLE SOLVED THESE
PROBLEMS, AND MAXWELL, FOR
INSTANCE, IS ONE EXAMPLE OF
SOMEONE WHO SOLVED STOKES
THEOREM BEFORE ACTUALLY STOKES
COULD FIND THE PROOF HIMSELF.
SO UNDER THE PRESSURE OF AN
EXAM, SOMETIMES YOU REALLY HAVE
GOOD IDEAS, OBVIOUSLY.

[Audience laughter]

Joao continues SO I'M NOT AWARE OF ANYONE
TRYING TO PLAY THIS GAME, AND
LIKE UNIFY GRAVITY AND THE REST
OF THE FORCES IN AN EXAM QUESTION.
THIS WOULD BE A VERY GOOD
EXAMPLE OF SOMETHING WHICH
COULD BE AS A QUESTION LIKE THAT.
SO LET ME JUST TELL YOU MY
PERSPECTIVE ON THIS, AND WHY
THIS RELATES TO THE VARYING C.
UM...
I'M NOT GOING TO GIVE YOU THE
ANSWER, AND I DON'T THINK
ANYONE HAS THE ANSWER, BUT I
THINK NOW WE KNOW WHY WE HAVE
FAILED.
AND THIS IS SOMETHING WHICH
GOES FOR A VERY SIMPLE
REASONING.
THIS IS BASICALLY THREE STEPS.
AND THIS GOES BACK TO THINGS I
INTRODUCED DURING THIS TALK, SO
YOU CANNOT COMPLAIN AND SAY, I
DON'T KNOW ABOUT THAT, BECAUSE
I'VE TOLD YOU ABOUT THAT
ALREADY.
BUT THE BASIC POINT IS THAT
GRAVITY IS THE THING THAT
ALWAYS STANDS APART.
SO IT'S ACTUALLY VERY EASY TO
UNIFY LIGHT, ELECTRICITY,
MAGNETISM AND NUCLEAR FORCES.
THE DIFFICULT THING IS GRAVITY.
GRAVITY IS THE THING THAT DOES
NOT WANT TO BE UNIFIED.
AND THE REASON IS, AS WE
UNDERSTAND IT...
SO THIS IS WHAT EINSTEIN TOLD
US.
GRAVITY IS THE CURVATURE OF
SPACE TIME.
ATOMS IN THE GREEK SENSE OF THE
WORD, OF COURSE.
SO BASICALLY, FOR INSTANCE, FOR
LIGHT, THE ATOMS OF LIGHT ARE
CALLED PHOTONS.
AND THIS IS WELL ESTABLISHED,
SO YOU KNOW, BASICALLY OF ALL
THESE THEORIES WHICH CAN BE
QUANTA, IF YOU WANT TO UNIFY
GRAVITY WITH EVERYTHING ELSE,
YOU HAVE TO QUANTIZE GRAVITY,
BECAUSE YOU CANNOT HAVE A
UNIFIED THEORY IN WHICH ONE
HALF IS QUANTIZED, THE OTHER
HALF IS NOT.
SO WE HAVE TO QUANTIZE GRAVITY,
BUT THIS MEANS QUANTIZING SPACE
AND TIME.
AND THIS IS REALLY QUITE CRAZY,
BECAUSE WHAT ARE YOU SAYING IS
THAT SPACE AND TIME ARE NOT
CONTINUED.
THEY SHOULD BE MADE OF ATOMS,
THEY SHOULD BE MADE OF
POTHOLES, SO TO SPEAK.
SO IN OTHER WORDS, THE TIME
SHOULD NOT BE LIKE SOMETHING
WHICH IS FLOWING CONTINUOUSLY,
IT SHOULD BE LIKE STEPS.
AND SPACE IS NOT SOMETHING THAT
YOU CAN MOVE SMOOTHLY AROUND,
BUT THERE SHOULD BE, LIKE,
POTHOLES AND YOU HAVE TO
LEAPFROG OVER THEM, IF YOU
REALLY COULD GO THAT SMALL.
SO UNIFYING ALL THE FORCES OF
NATURE MEANS PROPOSING
SOMETHING CALLED THE PLANCK
LENGTH AND PLANCK TIME, WHICH
WOULD BE THE ATOMS OF SPACE,
AND THE ATOMS OF TIME.
SO THIS IS THE IDEA, BUT
IMMEDIATELY YOU GET A PARADOX.
AND THE PARADOX IS, YOU KNOW,
ASK WHAT KIND OF OBJECTS WOULD
PERCEIVE THE EFFECTS OF QUANTUM
GRAVITY?
AND CLEARLY YOU NEED SOMETHING
WHICH IS VERY SMALL, BECAUSE IF
YOU HAVE SOMETHING THAT IS BIG,
YOU JUST SKIM THROUGH THE
POTHOLES OF SPACE.
YOU NEED A MICROSCOPE AND
SOMETHING REALLY SMALL THAT
WOULD BE FORCED TO LEAPFROG
OVER THESE QUANTA OF SPACE.
AND IMMEDIATELY YOU SEE WHAT IS
THE PROBLEM.
SO THE QUESTION IS, IS
SOMETHING BIG, IS SOMETHING SMALL?

A new slide reads "What kind of objects suffer from the effects of 'Quantum gravity'?
L sub p: Anything much larger than this is under the rule of classical gravity. Anything smaller than this should know that space has become full of potholes.

Joao continues WELL I TOLD YOU ONE THING, IT
WAS MY ATKINS DIET, YOU KNOW,
LENGTH CONTRACTION.
YOU BASICALLY HAVE THIS PROBLEM.
YOU ASK DIFFERENT OBSERVERS IF
SOMETHING IS BIG OR SMALL, AND
IT IS AGREED, BECAUSE OF COURSE
LENGTH IS NOT AN ABSOLUTE.
SO THIS IS THE REASON THAT, TO
MY MIND, WE HAVE A
CONTRADICTION IN TERMS.
ESSENTIALLY WE'RE TRYING TO--
WE'RE TRYING TO COMBINE TWO
THINGS, THAT ONE SAYS YES, ONE
SAYS NO.
WE'RE TRYING TO QUANTIZE
GRAVITY.
AT THE SAME TIME WE'RE TRYING
TO DO IT WITH RELATIVITY ON
TOP.
AND RELATIVITY DOES NOT LET YOU
DO THAT BECAUSE OF THIS
CONTRADICTION.
SO WHAT WE NEED -- SORRY ABOUT
THIS, IT WAS AN ACCIDENT.
WHAT WE NEED IS A THEORY WHERE
LENGTH CONTRACTION IS SOMETHING
THAT SWITCHES OFF, NOT FOR ALL
THINGS, NOT FOR BIG THINGS, BUT
WHEN THINGS BECOME VERY SMALL.
AND WELL, WHAT THIS MEANS IS
BASICALLY WHEN THE WAVELENGTH
OF A GIVEN LIGHT RAY BECOMES
THIS SMALL, ONE WAY TO DO THIS
IS TO SAY THAT THE SPEED OF
LIGHT GOES TO INFINITY.
AS YOU KNOW, AN INFINITE SPEED
OF LIGHT MEANS THE PRE-
RELATIVITY SPACE IN WHICH SPACE
IS ABSOLUTE.
SO THE ONLY WAY, TO MY MIND, TO
IMPLEMENT SOMETHING THAT'S NOT
A CONTRADICTION IN TERMS, IS TO
HAVE SOMETHING WHICH HAS A
WAVELENGTH OR AN ENERGY OR A
QUALITATIVE DEPENDENT SPEED OF
LIGHT, IN WHICH THE SPEED OF
LIGHT DIVERGES.
IT BECOMES INFINITE WHEN THE
WAVELENGTH BECOMES VERY SMALL.
THERE'S A BIT MORE PHYSICS
BASE, BUT YOU CAN SEE THAT
ESSENTIALLY WHAT I'M SAYING IS
THAT A COLOUR DEPENDENT SPEED
OF LIGHT IS A WAY TO GET OUT OF
THESE CONTRADICTIONS IN TERMS,
WHICH IS BEHIND QUANTUM GRAVITY.
SO PEOPLE ALWAYS ASK, WHAT IS
E=MC squared IN THIS THEORY?
I ALWAYS GIVE THE ANSWER, IT'S
NOT AS ICONIC AS E=MC squared, I
WOULDN'T PUT THIS ON A T-SHIRT
FOR SURE.
BUT IF YOU LOOK AT THIS A BIT,
THIS IS ACTUALLY THE KIND OF
EQUATION WHICH HAS THIS
PROPERTY THAT THERE IS AN
INVARIANT DIVISION BETWEEN
QUANTUM GRAVITY AND CLASSICAL
GRAVITY, SO THEREFORE YOU DON'T
HAVE A CONTRADICTION.
AND I SHOULD SAY THIS IS
SOMETHING WHICH HAS NOW BECOME
KNOWN AS DOUBLY SPECIAL
RELATIVITY.
IT'S NOT A SOLUTION TO
UNIFICATION, BUT IT'S SOMETHING
WHICH IS LIKE A MIDDLE GROUND,
WHICH IS NOT REALLY THE FINAL
ANSWER TO UNIFICATION, BUT IT'S
MORE LIKE A WAY OF TRYING TO
SIP OBSERVATIONS, TO GET
OBSERVATIONS INTO THE THEORY
BEFORE WE HAVE THE FINAL THEORY.
SO LET ME MOVE ON TO THE NEXT
THING, THE LAST THING I WANT TO
TELL YOU.
THE LAST THING I WANT TO TELL
YOU IS ACTUALLY ABOUT
OBSERVATIONS.
THE LAST TWO THINGS WERE REALLY
VERY THEORETICAL.
AND ALL I GAVE YOU IS MY
PERSPECTIVE AS A THEORIST, AS A
COSMOLOGIST, AS SOMEONE WORKING
ON QUANTUM GRAVITY, FOR WHY WE
WOULD THINK OF A VARYING C.
BUT OF COURSE IN THE END, THE
QUESTION IS, IS IT TRUE OR IS
IT NOT TRUE?
AND THIS IS SOMETHING THAT
CAME, SURPRISINGLY A YEAR AFTER
WE WROTE OUR FIRST PAPER ON
VARYING C.
SOMETIMES YOU GET THESE
SURPRISES.
THERE WERE SOME ASTRONOMERS
LOOKING AT THE SKY, LOOKING AT
MEASUREMENTS OF THINGS WHICH
CAN BE SEEN AS MEASUREMENTS OF
VARYING C.
OF C IN THE EARLY UNIVERSE, AND
THEY FOUND OBSERVATIONAL
EVIDENCE FOR THESE VARIATIONS.
SO THIS IS QUITE A STRANGE
THING.
I SHOULD TELL YOU THAT I'M
GOING TO CONCENTRATE ON ONE
TYPE OF VARYING SPEED OF LIGHT
THEORIES, THE ONES IN WHICH
THERE'S VARIATIONS IN TIME.
I TOLD YOU THERE ARE THEORIES
IN WHICH THE COLOUR IS A FACTOR
AS WELL.
BUT THEY'RE MORE COMPLICATED,
THEY ALSO HAVE INTERESTING
IMPLICATIONS.
AND THIS IS WHAT HAPPENED.

A new slide shows a picture of a large telescope at dusk.

Joao continues SO AT THE TIME, THERE WERE A
NUMBER OF PEOPLE WORKING WITH
THIS TELESCOPE IN HAWAII.
PEOPLE ALWAYS ASK, WHY HAWAII.
IT'S ACTUALLY-- THERE'S A GOOD
REASON FOR THAT.
IT'S NOT JUST A NICE HOLIDAY AT
THE END OF THE OBSERVATIONS.
BUT THIS IS THE KECK TELESCOPE
IN HAWAII WHERE THERE'S REALLY
A VERY-- A VERY GOOD WAY OF
LOOKING AT THE VERY DEEP
UNIVERSE, THE VERY EARLY
UNIVERSE, AND THIS IS SOMETHING
WHICH IS NOT WIDELY
APPRECIATED, BUT COSMOLOGISTS,
IN A WAY, ARE MUCH BETTER OFF
THAN ARCHAEOLOGISTS.
ARCHAEOLOGISTS ARE PEOPLE WHO
HAVE TO RELY ON RELICS OF THE
PAST, WHEREAS COSMOLOGISTS CAN
JUST LOOK DIRECTLY TO THE PAST.
THE REASON BEING, WHEN YOU LOOK
DIRECTLY AT THE STAR WHICH IS
VERY FAR AWAY, YOU'RE LOOKING
AT LIGHT THAT LEFT A LONG TIME
AGO, AND HAS BEEN TRAVELLING
TOWARDS YOU.
SO IF YOU LOOK AT SOMETHING
WHICH IS, SAY, A BILLION LIGHT
YEARS AWAY, YOU'RE LOOKING AT
LIGHT THAT LEFT ONE BILLION
YEARS AGO, AND HAS BEEN
TRAVELLING TOWARDS YOU.
AND NOW WE HAVE THIS REALLY
KIND OF-- THIS TIME LAG BETWEEN
OBSERVING AND EMITTING, WHICH
ALLOWS US TO LOOK DIRECTLY INTO
THE PAST.
SO WE'RE NOT INFERRING THE
PAST, WE'RE ACTUALLY LOOKING
INTO THE PAST.
WHEN WE LOOK VERY FAR AWAY...
WHEN I SAY FAR AWAY, THAT MEANS
LONG AGO.
SO FAR AWAY, LONG AGO, ARE
EQUIVALENT IN OBSERVATIONAL
COSMOLOGY.
AND WHAT THESE GUYS HAD BEEN
DOING IS LOOKING AT THESE
BEAUTIFUL THINGS CALLED
QUASARS.
SO THESE THINGS ARE REALLY,
REALLY ON THE FAR OUTER EDGES
OF THE UNIVERSE.

Six pictures show different quasars, resembling balls of fire in different shapes and sizes.

Joao continues THESE THINGS ARE CLOSE TO 10
BILLION LIGHT YEARS AWAY, WHICH
MEANS WE'RE REALLY LOOKING AT
THE VERY, VERY EARLY UNIVERSE,
NOT QUITE THE BIG BANG, BUT
WE'RE LOOKING AT THE UNIVERSE
VERY, VERY EARLY ON.
IT IS THE BABY UNIVERSE REALLY,
WE'RE LOOKING AT.
AND WHAT THESE PEOPLE FOUND IS
THAT THEY COULD ACTUALLY
MEASURE THIS CRAZY THING WHICH
LED PAULEY TO GO INTO A ROOM
137 SO THE FINE STRUCTURE
CONSTANT, I TOLD YOU, WAS GOING
TO COME BACK TO HAUNT US.
IT IS HERE AGAIN.
WHAT THESE GUYS CAN MEASURE, IS
ACTUALLY ALPHA AS IT WAS AT THE
TIME AT WHICH THIS LIGHT WAS
EMITTED.
SO YOU CAN SEE IMMEDIATELY YOU
HAVE ACCESS TO THESE VARIOUS
THINGS, THE ELECTRIC CHARGE,
THE SPEED OF LIGHT THE PLANCK'S
CONSTANT, YOU CAN MEASURE THIS
COMBINATION VERY ACCURATELY BY
LOOKING AT THIS LIGHT FROM
QUASARS.
SO THEY DEVELOPED THIS
TECHNIQUE, BASICALLY, THE IDEA
IS VERY SIMPLE.
YOU JUST LOOK AT THIS LIGHT,
AND IT CONTAINS THESE—THESE LINES.

Three coloured lines pop up on a new slide. The first shows a continuum of all the colours and reads "Continuous spectrum." The second shows only a few colours and reads "Emission spectrum." The third shows the colours in the second line missing from the spectrum in the first, and reads "Absorption spectrum."

Joao continues SO IF YOU JUST HAVE A
DISPERSION OF THIS LIGHT WITH A
PRISM, YOU GET A RAINBOW.
TYPICALLY YOU FIND THESE LINES
ON TOP OF IT.
AND THESE LINES DESCRIBE THE
WAY THE ATOMS, THE DIFFERENT
LEVELS IN THE ENERGY OF THE
ATOMS AS THEY WERE AT THE TIME.
AND YOU CAN ACTUALLY LOOK AT
THE WAY THIS THING SPLIT AND
BASICALLY THE WAY THIS LINE
SPLIT GIVES YOU A DIRECT
MEASUREMENT OF THIS QUANTITY
ALPHA, WHICH I DESCRIBED
EARLIER.
SO WHAT I'VE DONE-- IT'S VERY
EASY TO SAY, IT'S AN INCREDIBLY
DIFFICULT THING TO DO.
AND THIS HAS BEEN GOING ON FOR
MAYBE 7 YEARS NOW, AND THIS IS
WHAT THEY FOUND.
WHAT THEY FOUND IS, IF YOU JUST
PLOT THE LOOK BACK TIME, SO
THIS IS FURTHER AND FURTHER
BACK IN TIME, FURTHER AND
FURTHER AWAY IN SPACE, AND HE
SEES ESSENTIALLY THE PLOTS OF
WHAT YOU SEE FOR ALPHA, AND YOU
SEE THAT ALPHA BECOMES SMALLER.

A line chart pops up showing a line that curves down as it goes.

Joao continues THIS IS BLOWN UP.
IT'S A TINY THING.
WE'RE NOT TALKING ABOUT THE BIG
VARIATIONS WE NEED FOR
EXPLAINING THE HORIZON PROBLEM,
WE'RE TALKING ABOUT THE RESIDUE
SOME 10 BILLION YEARS AGO.
AND THIS IS BASICALLY WHAT THEY
SEEM TO HAVE OBSERVED.
THEY SEEM TO HAVE THIS VERY,
VERY KIND OF NUANCE HERE, THIS
FEATURE, WHICH IS VERY
SIGNIFICANT.
IT'S CONTROVERSIAL, AND IT
CONTINUES TO BE IN DISPUTE, BUT
I THINK IT'S INTERESTING THERE
MIGHT BE SOME OBSERVATIONAL
EVIDENCE FOR VARYING ALPHA.
SO EVERYBODY ALWAYS ASKS AT
THIS POINT, SO WHAT DOES THIS
MEAN?
IS IT THE VARYING C, IS IT THE
VARYING E, WHAT IS IT?
AND I DON'T KNOW IF THERE'S ANY
PHYSICS STUDENTS HERE.
SO I'M GOING TO LEAVE THIS AS A
PROBLEM FOR THE STUDENT.

[Audience laughter]

Joao continues AND I'M GOING TO GIVE YOU A
HINT THOUGH.
SO THIS IS-- YOU CAN ACTUALLY
ADDRESS THE QUESTION, IS IT A
VARYING ALPHA, IS IT A VARYING
C, OR WHATEVER IT IS.
SO THINK A BIT ABOUT IT.
WHERE DO THE CONSTANTS OF
NATURE COME FROM?
SO TYPICALLY THEY'RE VERY
CLOSELY RELATED WITH OUR
UNDERSTANDING OF WHAT ARE THE
UNITS OF MEASUREMENT.
THE CONSTANTS OF NATURE ARE
THINGS THAT DON'T CHANGE.
THE UNITS OF MEASUREMENT
SHOULDN'T CHANGE.
I DON'T WANT TO MEASURE THINGS
WITH A METRE STICK THAT KEEPS
CHANGING BACK AND FORTH, OKAY?
SO THE UNITS OF NATURE AND THE
CONSTANTS OF NATURE ARE VERY
CLOSELY RELATED.
AND FOR EXAMPLE, THIS IS AGAIN
FOR THE PHYSICS STUDENT IN THE
AUDIENCE, NEWTON'S LAW IS THE
STATEMENT THAT THE FORCE OF
GRAVITY DECREASES WITH THIS
COMBINATION, AND THEREFORE YOU
GET THIS PROPORTIONALITY
CONSTANT THAT'S NEWTON'S
CONSTANT.
WELL, GALILEO, BEFORE NEWTON,
THOUGHT ACTUALLY THE
ACCELERATION OF GRAVITY WAS A
CONSTANT.
SO THIS IS WHAT YOU USE
WHENEVER YOU LAUNCH A ROCKET
INTO SPACE, GRAVITY BECOMES
WEAKER AND WEAKER.
IN HEIGHT, GALILEO THOUGHT IT
WAS THE SAME.
YOU KEPT GOING UP AND THE
ACCELERATION OF GRAVITY WAS THE
SAME.
NOW THIS CONFUSES A LOT OF
PHYSICS STUDENTS, WHICH IS WHY
I LIKE TO DO THIS.

[Audience laughter]

Joao continues CONSIDER NOW THAT I DECIDE TO
DO THE MEASUREMENTS WITH A
PENDULUM CLOCK.
SO THE PENDULUM CLOCK IS SOMETHING...
I GO TO THE MOON, AND INSTEAD
OF TAKING, YOU KNOW, AN
ELECTRONIC CLOCK, I TAKE A
PENDULUM CLOCK.
IT'S A BIT
STUPID, I KNOW, BUT YOU JUST
TAKE A GRANDFATHER CLOCK TO THE
MOON, AND THAT'S WHAT YOU USE
TO MEASURE TIME ON THE MOON.
IT'S A BIT SURREAL, A BIT
RIDICULOUS, BUT IF YOU THINK A
BIT ABOUT THIS, IF THIS IS YOUR
UNIT OF TIME, THIS IS A VALID LAW.
IE, NEWTON'S LAW IS ACTUALLY
WRONG, AND GALILEO'S LAW IS
RIGHT, IF I INSIST ON GOING
AROUND THE UNIVERSE WITH A
PENDULUM CLOCK INSTEAD OF A
NORMAL ELECTRONIC CLOCK.
NOW ELECTRONIC CLOCKS ACTUALLY
TICK WITH ALPHA.
ALPHA IS THE THING WHICH
DETERMINES HOW YOUR WATCH TICKS.
AND BASICALLY, IF YOU HAVE A
VARYING ALPHA, EFFECTIVELY WHAT
YOU ARE DOING IS TAKING A
PENDULUM CLOCK AROUND THE
UNIVERSE.
IT'S EQUALLY STUPID, REALLY.
SO YOU KNOW, BASICALLY BY
ADDRESSING THESE ISSUES OF HOW
SHOULD WE DEFINE UNITS, IT'S
NOT METAPHYSICS, BUT BY
ADDRESSING THIS ISSUE, YOU WILL
ACTUALLY ANSWER WHETHER YOU
SHOULD HAVE A VARYING E OR A
VARYING C IF YOU HAVE A VARYING
ALPHA.
SO I REALLY HOPE THERE'S NOT
TOO MANY PHYSICS STUDENTS HERE,
BECAUSE YOU'RE GOING TO BE
REALLY CONFUSED.
THIS IS A PERFECT WAY TO
DESTROY -- AND IT DOES A LOT OF
TAUTOLOGIES IN PHYSICS
TEXTBOOKS, I DON'T KNOW IF
YOU'VE NOTICED THIS.
YOU DEFINE ONE THING, THE OTHER
THING IS DEFINED BY THE OTHER,
IT'S LIKE A LOOP.
AND YOU KNOW, THIS IS ONE
EXAMPLE OF WHERE YOU COULD PUT
THE FINGER IN IT.
SO BEFORE I FINISH, I'M GOING
TO WRAP THIS UP EXACTLY.
THESE ARE THE THREE THINGS I
WANTED TO TELL YOU.

A new slide reads "Three reasons for a varying speed of light.
Cosmology is begging for it.
Maybe a necessary ingredient for grand unification.
It may be true!"

Joao continues AND BASICALLY LET ME GO BACK TO
THE PHILOSOPHY, THE
PHILOSOPHICAL ISSUE.
COULD THE LAWS OF PHYSICS
CHANGE IN TIME?
WELL THIS IS A VERY BIG
QUESTION.
THIS IS SOMETHING I CAN BE HERE
THREE HOURS TALKING ABOUT IT.
I CAN BE HERE 48 HOURS IF YOU
WANT.
BUT LET ME JUST GIVE YOU LIKE
A-- BASICALLY THE SHORT ANSWER
IS, IT'S EXTREMELY DIFFICULT TO
PRECLUDE THE EXISTENCE OF A
SUPER LAW TELLING YOU HOW THE
LAWS YOU OBSERVE ARE CHANGING.
SO IF THE LAWS OF PHYSICS HAVE
TO CHANGE, THERE CANNOT BE SUCH
A SUPER LAW THAT DOES NOT
CHANGE ABOVE THEM.

A new slide reads "Can physical laws change in time due to varying constants?
It's possible, but you need a varying C and even then need to go to quite extreme measures.
It's viable experimentally, if done carefully."

Joao continues AND THE ONLY WAY I KNOW OF TO
DO THIS IS EXACTLY BY HAVING A
VARYING C.
BECAUSE THE SPEED OF LIGHT IS
SO INGRAINED SO EMBEDDED INTO
THE WAYS OF FORMULATING THE
LAWS OF PHYSICS, THAT IF YOU
HAVE A VARYING C, AND IF YOU DO
IT BRUTALLY, THEN ESSENTIALLY
YOU HAVE VARIABILITY TO
PHYSICS, TO THE PHYSICAL LAWS
IMMEDIATELY, AND THIS CAN BE
DONE IN A WAY THAT'S VIABLE
EXPERIMENTALLY, IF DONE
CAREFULLY.
SO IT'S A CRAZY PERSPECTIVE.
YOU'RE BASICALLY SAYING THE
UNIVERSE MIGHT COME OUT OF THE
NOTHING WITHOUT LAWS, AND THEN
INVENTED THE LAWS, AND THINGS
JUST CRYSTALLISED INTO A
STABLE... C IS NOT VARYING
MUCH, LAWS ARE NOT CHANGING
MUCH, A STABLE SCENARIO, BUT
BASICALLY THE REASON WHY THAT
HAPPENS MAY BE A CIRCUMSTANTIAL
REASON RATHER THAN A
FUNDAMENTAL REASON.
AND I THINK I SHOULD LEAVE THIS
HERE.
LET ME JUST CONCLUDE, AS I
SAID, IF I START GOING ON THIS,
IT WILL BE THREE HOURS.
SO MAYBE, LET ME JUST CONCLUDE
BY STATING THAT THE VARYING C
THEORIES HAVE QUITE A STRANGE
THING, GIVEN THAT IN 1905,
EINSTEIN PROPOSED THE THEORY OF
RELATIVITY.
IT'S CURIOUS THAT ACTUALLY THE
FIRST VARYING CONSTANT THEORY I
KNOW OF WAS PROPOSED BY KELVIN,
EXPERIMENTALLY IN 1874, AND WAS
THE VARYING SPEED OF LIGHT.
SO THIS KIND OF OPENNESS OF
MIND WAS SOMETHING WHICH WAS
POSSIBLE BEFORE 1905, THEN
EINSTEIN CAME UP WITH HIS
THEORY, AND LOOK AT THIS
AMAZING STATEMENT.
THIS IS AN INCREDIBLY STUPID
THING TO SAY IF YOU THINK A BIT
ABOUT THIS.
THIS IS NOT SOMETHING WHICH IS
ACTUALLY DOING RELATIVITY ANY
FAVOUR.
YOU'RE SAYING THAT THE
CONSTANCY OF C IS ACTUALLY A
DEFINITION, IT'S SOMETHING
PHYSICAL.
OF COURSE THAT'S NOT TRUE.
IN FACT, WHAT HAS HAPPENED IS
THAT THE PHYSICAL REASONS, THE
EXPERIMENTAL REASONS THAT LED
TO RELATIVITY THEORY, BY 1930
HAD BEEN FORGOTTEN.
AND PEOPLE HAD BECOME
COMPLETELY EMBROILED IN THE
MATHEMATICS OF RELATIVITY
WITHOUT REALISING THAT ACTUALLY
THINGS COULD HAVE BEEN
DIFFERENT.
AND THE QUOTE I LIKE VERY MUCH
FROM EINSTEIN, WHICH COMES FROM
AROUND THE SAME TIME...

A new slide reads "Since mathematicians invaded relativity I don't understand myself anymore."

[Audience laughter]

Joao continues I THINK THIS IS THE SITUATION
WE'RE IN AT THE MOMENT.
I THINK A LOT OF THE PHYSICS
WHICH IS BEHIND RELATIVITY HAS
BEEN FORGOTTEN.
AND NOW IT'S EVERYTHING IS JUST
SO MUCH FORMALISM, SO MUCH
MATHEMATICS, THAT PEOPLE FORGET
THAT THINGS COULD HAVE BEEN
DIFFERENT, AND MAYBE THERE'S
GOOD PHYSICAL REASONS FOR THEM
TO STILL BE DIFFERENT.
RELATIVITY WAS REALLY DUE TO
EXPERIMENT, NOT TO MATHEMATICS,
NOT TO SELF-CONSISTENCY, AS
EDDINGTON CLAIMED, AND IF
SOMETHING IS DUE TO EXPERIMENT,
I LIKE THIS QUOTE AS WELL, AND
I'LL FINISH WITH IT...

A new quote reads "What is due to experiment may always be rectified by experiment."

Joao continues THANK YOU.

[Applause]

The clip ends. Back in the studio, Andrew Moodie appears with a caption reading his name.

He says NOW, MAGUEIJO
IS NOT THE FIRST TO PROPOSE THE
VARYING SPEED OF LIGHT THEORY.
JOHN MOFFATT,
A CANADIAN, A SELF TAUGHT
PROFESSOR EMERITUS IN PHYSICS
AT THE UNIVERSITY OF TORONTO,
SUBMITTED A PAPER IN THE EARLY
'90s TO PHYSICAL REVIEW, A VERY
PRESTIGIOUS PHYSICS MAGAZINE...
AND IT WAS REJECTED.
MR. MOFFATT, YOU, OF COURSE,
WERE THE FIRST APOSTLE TO
CHALLENGE THE SUPREMACY OF THE
CONSTANCY OF LIGHT AND IT'S NO
SURPRISE TO ME THAT MOFFATT AND
MAGUEIJO AND OTHERS ARE CALLED
THE PUNK ROCKERS OF PHYSICS.
THEY DON'T SEEM TO CARE ABOUT
ELEGANT SCIENTIFIC EQUATIONS OR
UNIFIED FIELD THEORY.
AND HONESTLY, IT MAKES SENSE TO
ME THAT THE UNIVERSE DOESN'T
FIT INTO A NICE TIDY CLEAN
EQUATION THAT YOU CAN PUT ON A
CHALK BOARD.
THE CRITICS OF MAGUEIJO,
HOWEVER, HAVE A MAJOR HUGE
VALID POINT.
THE VARYING SPEED OF LIGHT
THEORY BREAKS ONE OF THE
FUNDAMENTAL LAWS OF PHYSICS,
THE CONSERVATION OF ENERGY.
YOU LOSE THAT, THEN A LOT OF
SCIENCE THAT HAS DONE AN
EXCELLENT JOB OF EXPLAINING A
LOT OF PHENOMENA GOES RIGHT OUT
THE WINDOW.
WHAT MAGUEIJO NEEDS IS
EVIDENCE, AND THAT'S WHAT JOHN
WEBB, AN ASTRONOMER AT THE
UNIVERSITY OF NEW SOUTH WALES
MAY HAVE GIVEN HIM.
WEBB'S OBSERVATIONS OF A
QUASAR, WHICH IS A KIND OF A
SUPER BRIGHT GALAXY, SHOWS THAT
LIGHT COULD HAVE HAD A
DIFFERENT SPEED IN THE EARLY
UNIVERSE.
IF HE'S RIGHT, THEN WE LIVE IN
A UNIVERSE WHERE ENERGY AND
MATTER CAN WINK IN AND OUT OF
EXISTENCE, WHERE RELATIVITY IS
DEAD, AND WHERE WE WILL BE
HEARING A LOT MORE FROM JOAO
MAGUEIJO.
NOW, IF YOU'LL EXCUSE ME, I
HAVE TO EXPLAIN TO MY DAUGHTER
WHAT A STAR IS.
WISH ME LUCK.
BUT NO LUCK IS REQUIRED TO BE
INFORMED ABOUT WHAT IS COMING
UP ON OUR PROGRAM.

The caption changes to "bigideas@tvo.org"

Andrew says IF YOU'D LIKE
WEEKLY UPDATES, SEND US AN E-
MAIL AT...
NOW, HERE ARE A FEW EXCERPTS OF
WHAT WILL BE ON
BIG IDEAS
IN THE WEEKS TO COME.

Now a clip plays with the caption "Coming up, Steven Levitt."
In the clip, Steven Levitt addresses an unseen audience.
He's in his early forties, clean-shaven, with short gray hair.

He says MOST ECONOMISTS HAVE TAKEN THE
APPROACH WHICH IS, WELL, I
CAN'T ANSWER VERY WELL THE
QUESTIONS I REALLY CARE ABOUT,
LIKE, YOU KNOW, HOW DO YOU KEEP
GOVERNMENT--
HOW MUCH CORRUPTION IS GOING ON
IN GOVERNMENTS, OR HOW DO YOU
CATCH TERRORISTS, OR SOMETHING
LIKE THAT.
AND SO THEY SAY, WELL LET'S
MOVE ON TO SOME QUESTIONS THAT
WE CAN ANSWER BETTER.
SO I KIND OF TOOK A DIFFERENT
APPROACH WHICH IS TO SAY WELL
I CAN'T REALLY ANSWER THE
QUESTIONS I CARE ABOUT WITH
RESPECT TO CHEATING, SO WHY
DON'T I ANSWER A BUNCH OF
QUESTIONS I DON'T CARE ABOUT,
TO AT LEAST SEE IF I CAN ANSWER
THOSE, AND MAKE SOME HEADWAY,
WHICH IS NOT YOU KNOW, WHICH I
CAN UNDERSTAND WHY OTHER PEOPLE
DON'T DO IT, BUT I'M A VERY
SELF-CENTRED ECONOMIST, MAYBE
THERE'S NO OTHER KIND.

Now Richard Harris, in his fifties, bearded, with white hair, says
SOMETIMES WHEN PEOPLE TALK
ABOUT CITIES, WHAT THEY MEAN
ARE BIG PLACES, MORE THAN A--
WITH A POPULATION OF MORE THAN
100,000 OR A MILLION, OR 10
MILLION, AND THAT'S NOT WHAT I
MEAN TODAY.
THERE'S NOTHING MAGICAL ABOUT
ANY PARTICULAR NUMBER.
HAMILTON, FOR EXAMPLE, MY
ADOPTED HOME TOWN, DIDN'T
BECOME A DIFFERENT KIND OF A
PLACE WHEN ITS POPULATION
REACHED 100,000 OR 500,000 AS
IT IS NOW.
OF COURSE THE FOLKS FROM
TORONTO WOULD SAY, MORE'S THE
PITY, BUT US FOLKS IN HAMILTON,
WE HAVE THICK SKINS AND WE
IGNORE THOSE KINDS OF CHEAP
SHOTS.
THERE IS NO MAGICAL NUMBER, RIGHT?
WE'RE TALKING ABOUT A CONTINUUM.
SHANGHAI TODAY, WITH ITS
POPULATION OF WHATEVER IT IS,
BUT IT'S CERTAINLY MORE THAN 10
MILLION, AND GROWING RAPIDLY,
IS OBVIOUSLY VERY, VERY
DIFFERENT FROM A PLACE LIKE
BASSETERRE, WHICH IS A CITY I
HAVE BEEN LOOKING AT.
IN THE 1930s, VERY DIFFERENT
YES, BUT THERE ARE CERTAIN
QUALITIES THAT IT SHARES.
THEY'RE ON A CONTINUUM, AND
THAT WHY, WHEN I TALK ABOUT
CITIES TODAY ANYWAY, I'M
TALKING ABOUT CITIES OF ALL
SIZES.
WELL, IT SEEMS TO ME, AND THIS
IS REALLY, I SUPPOSE, THE MAP
OF THE REST OF WHAT I WANT TO
SAY TODAY.
IT SEEMS TO ME THAT THERE'S
REALLY THREE WAYS OF LOOKING AT
CITIES.
NOW I HAVE LABELLED THESE, THE
DUMB, THE PASSIVE AND THE ACTIVE.
AND JUST TO CLEAR UP ANY
CONFUSION, AND MAKE SURE I
DON'T OFFEND ANYONE, THESE
ADJECTIVES REFER TO, OR ARE
MEANT TO REFER TO THE
CHARACTERISTICS OF THE CITIES
AS SEEN BY EACH OF THESE THREE
POINTS OF VIEW.
THEY ARE NOT MEANT TO REFER TO
THE CHARACTERISTICS OF THE
PEOPLE WHO ADOPTED THESE POINTS
OF VIEW.

Back in the studio, Andrew says FOR BIG IDEAS,
I'M ANDREW
MOODIE.
SEE YOU NEXT TIME.

[Theme music plays]

The end credits roll.

bigideas@tvo.org

416-484-2746

Big Ideas. Producer, Wodek Szemberg.

Producers, Lara Hindle, Mike Miner, Gregg Thurlbeck.

Logos: Unifor, Canadian Media Guild.

A production of TVOntario. Copyright 2006, The Ontario Educational Communications Authority.

Watch: Joao Magueijo on The Changed Laws of Physics