Professor Al-Khalili
BBC (2011)
http://topdocumentaryfilms.com/everything-and-nothing/
EXCERPTS:
PART.1 - EVERYTHING
"Our sun is just one of a multitude of stars.
It's surrounded by over 200 billion of them in our own Milky Way Galaxy alone.
Our sun is just a speck in the vast beach of stars.
But the Milky Way Galaxy is in itself just one of 100 billion galaxies scatted throughout the cosmos."
"What's the totality of everything there is?
Crab Nubula were seen in the sky in 1572.
".. it shines five billion times more brightly than our own sun.
In 1572, a supernova like this would have become visible on planet Earth.
.. And to anyone who saw it, it must have been an extremely shocking and mysterious sight.
This new light in the night sky shone more brightly than Venus and even became visible during the day."
"Digges shows it, unlike Copernicus, Diggs shows it as being infinite.
This is a sphere, he says, of the stars fixed infinitely up.
Digges raised the question. If Universe is infinite and static then why the night sky is not as bright as day (Olbers' paradox).
Answer lies under the 'static', universe is not static.
WILLIAM HERSCHEL, metallic telescopes, discovery of Uranus
FIEDRICH BESSEL worked out to measure the accurate distances in outer space.
"The diameter of the Earth's orbit is 300 million kilometers.
HENRIETTA LEAVITT, true size of the universe.
"The idea that our Milky Way might contain everything that existed was about to crumble."
"The scale of the universe is really only understood amazingly recenlty.
In the 1920s, it was absolutely plausible that the universe consists of one galaxy,
and some of the best astonomers in the world, in the us for example,
seriously held that view, and had good evidence that it was true.
And they were wrong."
"The evidence to finally settle the great debate would be found
thanks to the powerful new Hooker telescope being build at the Mount Wilson Observatory
just outside Los Angeles.
Using this incredible piece of technology, and Henrietta leavitt's ingenious method
for calculating distance,
a young astronomer would make a discovery that would change our view of the universe
and for ever immortalise his name.
The astronomer was called Edwin Hubble."
Andromeda, our galactic neighbor, 2.5 million light years away.
"contains over a trillion stars."
Euclid's Geometry.
Carl Friedrich Gauss.
"Specifically, Gauss began to see that in curved spaces,
other types of geometry could exist, with different rules to Euclid's.
For exampe, on the surface of a sphere, the angles of a triangle can add up to more than 180 degrees." (90+90+90 = 270)
"Einstein would reveal that we live not in the flat world of Euclid,
but in the strange curved worlds of Gauss and Riemann."
"In the space of a few short years,
Einstein went from wrestling with some of the most difficult and abstract mathematical ideas to dinner dates with Charlie Chaplin.
And it was all thanks to the pinnacle of his life's work -
the General Theory of Relativity.
In the General Theory of Relativity Einstein took the mathematics of Gauss and Riemann
and used it to paint a revolutionary picture of the physical world."
"They revealed that it was the presence of mass that caused space to curve and distort.The reason we have gravity on Earth is because the Earth is actually bending the space around it."
"Gauss, Riemann and Einstein, had between them come up with a description of how the SPACE and TIME we exist in can be warped.
They showed that space and time are not the FIXED, unchanging stage on which the actions of the universe are played out.
They are actually part of the performance."
Einstein refused to believe that the universe is expanding, its dynamic and changing.
"In fact, he was so convinced that it was static, that he was prepared to modify his original equations by adding an extra turn , called the cosmological constant that would stabilise the universe.
But Einstein was trying to fix something that wasn't broken.
Armed with the Hooker telescope,
Hubble would reveal the truth that Einstein had refused to believe.
After discovering that our galaxy was just one of many,
Hubble began to study the ways in which these other galaxies were moving."
"Hubble knew that, as a light source approaches us, the light wave would become COMPRESSED and appear BLUE ./\/\/\/\/\/\/
If an object was receding, the light waves become STRETCHED OUT and appear RED. / \ / \ / \ / \ /
What he saw was astounding. All distant galaxies were being red shifted.
They were all moving away from us.
Not only that, BUT FURTHER AWAY A GALAXY WAS, THE FASTER IT WAS MOVING AWAY.
"Hubble's observations and Einstein's general theory of relativity were in agreement.
BUT, and this is the crucial point here, IT'S NOT THAT THE GALAXIES ARE FLYING AWAY FROM EACH OTHER THROUGH SPACE.
BUT RATHER THAT THE FABRIC OF SPACE ITSELF, IN BETWEEN THE GALAXIES, IS EXPANDING.
So the universe in its entirety is getting bigger.
This is what Hubble and Einstein's work revealed."
"Our entire universe is 13.7 billion years old."
"Ok, so here it is, here's where i hope this all makes sense.
The further away a star is, the longer it would take for its light to reach the Earth.
So, if the universe has been around forever, then all the light that's out there will have had time to reach us, and the night sky would be ablaze with starlight.
But it's not.
And here's why.
Imagine when the universe was much younger and smaller than it is today.
A beam of light on the other side of the universe begins a journey towards our vantage point.
But, as space expands, the distance the light has to cross keeps getting bigger and bigger.
Fast forward to today, and this light still hasn't reached us.
So, no matter how hard we look into the sky,
we simply won't be able to see it.
We can only see the stars whose light has had time to reach us
in the 13.7 billion years since the Big Bang.
This region is known as the observable universe.
And there are not enough stars here to light up the night sky.
So, we only ever see the stars and galaxies whose light has had a chance to reach us,
and that's why it gets dark at night."
"It took 200 years of theorizing, of thinking, it took the development of general relativity,
before we could understand why the sky at night is dark."
"If the expansion of the universe continues to accelerate (as it does)
then our visible universe will begin to empty.
Let me explain. Imagine that I'm in a distant galaxy that you can see from Earth.
As the space between us stretches there will come a time in the future when it is expanding so rapidly that light can't outrun it, and the galaxy will disappear from view.
What this means
is that , far into the future, some 100 billion years from now,
if intelligent life forms still exist in our galaxy,
they'll look out into space and see only the stars in our own Milky Way.
All the other galaxies will have disappeared.
And they will be alone in a vast, dark, empty expanse."
________________________________
PART.2 - NOTHING
"This film tells the story of how we've begun to understand what is known as the void,
or the vacuum, emptiness or simply nothing.
"Today, we believe the 'void' contains nature's deepest secrets.
It might even explain why we exist at all.
And that's because, to the best of our knowledge,
the entire universe appeared nearly 14 billion years ago
OUT OF NOTHING."
"For over 1000 years,
our understanding of empty space was defined by one man -
the Greek philosopher Aristotle.
.. He came to believe that nature would forever fight against the creation of true nothingness.
As he put it, nature abhors a vacuum."
"The man who would finally do what Aristotle thought impossible
was an Italian Jesuit called Evangelista Torricelli.
ATMOSPHEREIC PRESSURE
"We live at the bottom of an ocean of air." Torrecelli
"Pressure of the air fell as you went higher." experimented by Blaise Pascall
"Pascal's experiments would lead to the realization that the Earth is cocooned in an atmosphere that rapidly thins out the higher you go...
eventually becoming the cold, silent expanse of space.
Torricelli and Pascal had begun to unravel a profound truth -
NOTHING IS EVERYWHERE.
"NATURE DOESN'T ABHOR A VACUUM.
A VACUUM IS NATURE'S DEFAULT STATE.
"What exactly were the properties of nothingness?
"The vacuum wasn't empty at all.
The fact that they could see insdie it
meant that there still had to be something left in there.
Just as air carries sound waves,
they believed there had to be a medium carrying the light waves.
And whatever it was, it was proving very difficult to get rid of.
"And if that this substance existed in our vacuums on Earth,
it meant that it also existed out there.
It appeared once again that NOTHINGNESS COULD NOT EXIST IN NATURE.
Everything in the universe appeared to be sitting within an INVISIBLE MEDIUM,
what scientists called the lunineferous aether.
ALBERT MICHELSON, the scientist who conducted it, (experiment to measure speed of light)
would go on to become America's first Nobel Prize winner.
"How could light always be traveling at the same speed?
Well, the answer is simple. The aether doesn't exist."
"So the message from the failure of Michelson and Morley's experiments is this -
THERE IS NOT AIETHER.
May be the vacuum is really empty.
If only it were that simple.
Everything from the light bulb to the television
were only made possible because they could contain withing them
small volumes of vacuum.
The filament inside a light bulb can glow for long periods
because it is contained within a vacuum.
Expose it to air and it would simply burn out in seconds.
Because vacuum technology was getting so much cheaper, and more efficient,
scientists all over the world could use it as a tool for research.
In empty space, nature's tiniest constituents could now be studied
without interfernce from the contaminant-filled air of the outside world.
THIS REVOLUTIONISED PHYSICS.
Because of the 'vacuum':
X-rays were discovered in 1895.
The following year, the electron was identified for the first time.
And n 1909, Ernest Rutherford would use vacuums to help reveal the strange structure of the atom.
These discoveries were all feeding into a radically new picture
It was a theory that would come to be known as quantum mechanics.
Heisenberg's Uncertainty Principle.
"The world of quantum physics, the microscopic world,is a world of uncertainty.
.. nature itself is based on uncertainty."
"More i know about where something is,
the less i know about it is moving."
in a quantum world.
I cannot at the same time know both these quantities exactly.
VACUUM IS ALIVE.
"The vacuum, contrary to what one normayll expects from the vacuum, is alive,
It's alive with what physicists call Quantum Fluctuations.
IN THE VACUUM, LITTLE PACKETS OF ENERGY APPEAR AND DISAPPEAR VERY VERY QUICKLY.
This is perfectly allowed by the laws of physics.
It's all allowed but it has an name, its called Heisenberg's Uncertainty Principle.
which tells us that you can BORROW ENERGY FROM NOTHING, so long as you pay it back quickly enough."
PAUL DIRAC, BRITAIN Theorist physicist
Dirac's Equation. Anti-Matter
"By 1928, physics was struggling with a big problem.
The tow most important theories that described how the universe worked,
didn't agree with eachother.
On the one hand, you had Einstein's special theory of relativity
encapsulated in the famous equation E=mc2.
It was a beautiful, simple and elegant theory that describes the behavior of thing close to the speed of light.
On the other hand, you had Planck's discovery of the Quantum
and the revolution that followed describing the bizarre rules of the very very small.
...
It would be Dirac who would achieve this. (marriage of both theories)
"In fact, Dirac once said that the equation was smarter than he was
because it actually gave more stuff out than he put into it."
"If the vacuum were truly empty, this 'peak' wouldn't exist, we'd just get a flat line.
What this is telling us is that however hard we try to remove everything we can from space, we can never get it truly empty.
Everywhere in the universe, space is filled with this vacuum that has deep, mysterious energy."
"The theory of quantum mechanics is the most accurate and powerful description of the natural world that we have."
"Today, our best theories about the cosmos tell us that at the beginning of time,
the universe sprang from the vacuum.
Creating not only vast amounts of matter, but also the strange stuff that was predicted by Paul Dirac - Anti-Matter.
But the universe we see today is made of matter, nearly all of the anti-matter seems to have vanished."
"So, we are simply the debris of huge annihilation of matter and antimatter at the beginning of time. The leftovers of unimaginable explosion."
"What we once thought of as the void
now seems to hold within it, the deepest mysteries of the entire universe."
_______________________________
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