The first course of the specialization ANALYZING COMPLEXITY will teach you what unifying patterns lie at the core of all complex problems. It advances your knowledge of your own field by teaching you to look at it in new ways. ANALYZING COMPLEXITY is constructed in the following way: Week I. "What is Complexity?" - What is at the core of all complex problems Week II. "Complex Physical Systems" - What complex problems all have in common in the inanimate world Week III. "Complex Adaptive Systems" - What complex problems all have in common in nature Week IV. "Complex Cultural Systems" - What complex problems all have in common in human society Week V. "Complexity, Fragility, and Breakdown" - Why complex problems arise Week VI. "Complexity in the Anthropocene" - What complex problems face us today
Cosmic Complexity
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Del curso dictado por Macquarie University
Analysing Complexity
33 calificaciones
De la lección
Complex Physical Systems
In this module, we'll look at how complexity operates in the inanimate universe, the corresponding links between physics, chemistry, and geology and how they reflect the ground rules of all forms of complexity.
Conoce a los instructores
David BakerAssociate Lecturer
Big History Institute
David ChristianProfessor
Big History Institute
Shawn RossAssociate Professor
Big History Institute
The big question for this segment is, how complex was the universe
just after the Big Bang and what forms of complexity were there?
[MUSIC]
Our knowledge of the very early universe is uncertain,
hidden behind the wall of flame beyond which we cannot see.
It becomes increasingly difficult to see the early universe
before 380,000 years after the Big Bang.
Though with the beginning of our investigation into gravitational waves, we
may someday see beyond that wall of flame to the earliest moments of the cosmos.
But all the cosmological data so
far collected paints a fairly reliable picture.
A hot and dense universe expanding, growing cooler, and less dense over time.
This had a profound effect on complexity.
For frame of reference, computer modelling and
mathematical calculations have shown that in the first fraction of a second of
the universe's existence, that the bubble of the cosmos was about a trillion
times a trillion times a trillion more dense than water.
It was also about ten to the power of 21 Kelvin,
that's a one with 21 zeroes, whereas water boils at just 373 Kelvin.
That's quite a thick and piping hot bowl of primordial soup.
Even the surface of a star is not nearly that hot,
clocking in at a few thousand Kelvin.
Within that soup, what sort of chunks of complexity do we find?
In the first few seconds, almost none.
The most basic tiny particles just emerging.
There are about 200 elementary particles known to science.
Of these, the collection of quarks, the ingredients for the protons and
neutrons of atoms were not able to come together in that intense fireball to
form more complex structures or systems.
Without the ability of building blocks to come together,
you can't really have structures through which energy can flow.
Without flow of energy you don't really have any complexity.
After the first few minutes, quarks formed protons and neutrons.
And in turn protons and neutrons began to form the nuclei of atoms.
This is because of the expansion of the universe,
which made the first real complexity possible.
Over the next few centuries, the universe cooled to a temperature and
densely comparable to most stars today.
Nevertheless, because matter and radiation were intimately coupled,
the early universe remained a uniform highly structural blob.
Not a lot of energy flow.
Not a lot of structure.
Not a lot of complexity.
The reason why the early universe was so hot is because of pressure.
Throw all the ingredients of the cosmos into a concentrated heap and
heat is generated.
The same goes to a much lesser degree for the massive clumps of hydrogen and helium
gas that form a star, or the molten core of a sufficiently large planet like Earth.
But then, let us back up, why did any complexity emerge in the universe at all?
Why wasn't the universe born stillborn, uniform, dead, at equilibrium,
without any future for complexity in the cosmos?
Well, at approximately 10 to the power of -35 seconds, at the quantum scale,
there were tiny particles popping in and out of existence, just as there
are the same virtual particles bubbling in the room you are sitting in right now.
Usually, these virtual particles are too small to have any impact on the universe
at larger scales.
But during the earliest phases of cosmic inflation,
the universe started from small enough a size, much smaller than an atom or
even a quark, that these quantum variations were able to have an impact,
and these variations suddenly were writ large when the universe
became the size of a grapefruit in the fraction of a blink of an eye.
The writing these fluctuations left on the cosmic wall,
still visible in the picture of cosmic background radiation created
minute variations in the distribution of matter and energy in the universe.
Those tiny footprints at the quantum scale are responsible for
all the increasing complexity that followed in the next 13.8 billion years.
We owe our entire story to them.
In time, those tiny variations were to clump together hydrogen and
helium in stars, which in turn produced chemical elements, planets, and us.
All that came from a tiny blip that happened in a sliver of a second
at the beginning of space and time.
Over the next three minutes, the universe cooled to the point that quarks
formed into protons and neutrons, which in turn formed the nuclei of hydrogen and
helium that make up the vast bulk of atomic matter in the universe.
This laid the groundwork for most of the heavier elements that form in the bellies
of stars and the firestorms of supernova.
Then, after another 380,000 years, the universe expanded further and
cooled to a balmy 3,000 Kelvin.
At these temperatures radiation was able to travel more freely,
racing out in a blinding flash, leaving matter to grow more dominant and
capture electrons, becoming fully fledged atoms.
Even then we are talking simplest of all elements, hydrogen and
helium, making up the overwhelming majority of matter in the early universe.
In terms of building blocks, they are pretty simple.
A hydrogen atom is made up of one proton and one electron.
Helium is slightly more complex, in a grouping of two protons, two neutrons,
and two electrons.
But compare that to iron, the heaviest element forged in the belly of a star,
which is 26 protons, 13 neutrons and 26 electrons.
When stars go nova, they produce elements like gold, 79 protons, 118 neutrons,
79 electrons, and uranium, 92 protons, 146 neutrons and 92 electrons.
But these would need to wait for
the explosive firestorms of supernova in order to form.
All told, the early universe was not a very complex place.
Not at least until gravity capitalized on minute inequalities in the distribution of
hydrogen and helium atoms, sucking them into deeper and
deeper concentrations, until the heat and pressure built up so much that the first
stars flared into life and the universe got a little warmer once again.
Even then, these first stars were not very complex structures.
The density of energy flows in your average star is many hundreds or even
thousands of times lower than the density of energy flows in a living organism.
They are also structurally simple, great lumps of pressurized hydrogen and
helium with trace amounts of other elements.
They were, however, the first complex systems in the universe that was rapidly
cooling to only a few degrees above absolute zero, and
a universe that is 99.99999% space.
But this was the universe's first attempt to claw a little further away from
total uniformity and simplicity.
Stars were the first structures through which
energy could flow in a complex system, and as a result,
produced the atomic structures that yielded organic chemicals, life, and us.
The rest, as they say, is history.
[MUSIC]
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