Humanity and Science in Perspective

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Humanity and Science in Perspective
CC105
Prof. Jackson
Today’s Music
“The Universe Song”
Monty Python
Today’s Lecture
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The story of everything
Math in Nature
The cosmic size-scale
The cosmic time-scale
Science and truth
Humans
The future
What is Science?
“Science is the marriage of skepticism
and wonder.”
Carl Sagan
The Story of Everything
• In the beginning…Big Bang, and there was
light.
• Primordial soup spawns particles, and
eventually hydrogen and helium.
• Stars form from the hydrogen/helium gas.
• Stars make heavy elements and explode.
• More stars form, enriched with heavy
elements.
• The Sun forms
• The Earth forms as a byproduct
• Chemistry on earth spawns life
• Humans evolve from ancient ancestors.
“It is Nature herself, and not the
mathematician, who brings
mathematics into natural
philosophy.”
Kant
Math in Nature
• Does math form the fundamental basis
for everything?
• Math revealed in nature
– LAWS
– FORMS
Symmetry
In mathematics, “symmetry’’ refers to
an operation that leaves an object
unchanged.
Reflect through
a mirror
Rotate by 90o
Crystals
Ice: hexagonal symmetry
Ice
Edward
Weston
What about life?
• Many creatures have mathematical
shapes
• Many creatures exhibit symmetries
– Bilateral
– Rotational
Mathematical Forms in Life
Equiangular Spiral
 / 0
R  R 0e
The Chambered Nautilus
Edward Weston
Nautilus Shell
A perfect
logarithmic
spiral!
More Equiangular Spirals
More spirals
Bilateral Symmetry
Bilaterally Symmetric Life
Bilaterally Symmetric Life
Edward Weston
Bilaterally Symmetric Life
Edward
Weston
Bilaterally Symmetric Life
Edward
Weston
Rotational Symmetry
Rotationally Symmetric Life
Rotationally Symmetric Life
Rotationally Symmetric Life
Rotationally Symmetric Life
Rotationally Symmetric Life
Mushroom Gills
Mushrooms
Gill
spacing
never too
large
Fractals in nature
• Fractals are objects that look the same
regardless of the magnification.
• “Scale-invariant”
Fractals
River
drainage
More fractals
More fractals
More fractals
More fractals
Fractal Life
Fractal Life
Fractal Life
Fractal Life
Fractal Life
Fractal Life
Examples of fractals in nature
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Trees
Lungs
Viscous fingers (fluid flow)
Rain clouds
Electrical discharges
Shorelines
Amplitude
Fractals in music:
Music is pink noise
Frequency
White noise
Af
Pink noise
Af-1
Brown noise
Af-2
Mathematics is relevant
It is everywhere, and part of
everything, both inanimate and
animate.
The Cosmic Perspective
• Where do humans fit in?
• Size
• Time
The Cosmic Size Scale
Movie: Powers of Ten
The Cosmic Time Scale
• The Universe began about 14 billion
years ago.
• The solar system formed about 5 billion
years ago.
• Life appeared 3 billion years ago.
• Homo sapiens appeared 100,000 years
ago.
The Cosmic Time Line
Universe begins
Solar system forms
15 billion yr
Earth forms
5 billion yr
10 billion yr
Life begins
4 billion yr
3 billion yr
today
5 billion yr
Trilobites
2 billion yr
1 billion yr
today
The Cosmic Time Line
Universe begins
15 billion yr
Trilobites
500 million yr
Solar system forms
10 billion yr
Fishes
Amphibians
300 million yr
5 billion yr
Reptiles
today
Mammals Hominids
100 million yr
If Eternity Were A Year:
Compress 14 billion years into one
Sun forms: Late August
Earth forms: September 1
Life begins: Late September
Land animals: December 20
Dinosaurs: December 29
Hominids: 10:00 pm, December 31
Homo sapiens: 11:53 pm December 31
“It is more important to have beauty in
one’s equations than to have them fit
experiments.”
Paul Dirac
Science and beauty
• Why does aesthetics play such an
important role in science?
• Perhaps our notions of “beauty” reflect
a concordance with the underlying
mathematical structure of Nature.
• Is beauty truth? Or is truth beautiful?
The Faith behind Science
• The Universe is built on a foundation of
order.
• The Universe is explicable.
• The Universe is mathematical.
• Nature operates with a few simple laws.
• These laws have the same rules
everywhere.
Science and truth
Science is only as good as its predictions!
Important to distinguish between the
ideas and the predictions.
Science provides a quantitative
description of Nature.
Can only describe reality within the limits
of the human mind.
Science may never arrive at truth.
And yet…
Some ideas work so well they seem
indistinguishable from truth:
– Atoms
– Gravity
Why does it work?
• Empiricism: go to Nature for answers
• Reject bad theories.
“The great tragedy of Nature is the
murder of beautiful theories by ugly
fact.”
Mark Twain
Questions science cannot (yet) answer
• Is there existence after death?
• What is reality?
• Why is there something rather than
nothing?
• What defines good and evil?
Science and religion and philosophy
Science seems to be encroaching on
themes formerly addressed by
philosophy and religion
• Creation
• The nature of reality
• The origin of humans
• Our place in the Cosmos
• The mind
Where Do Humans fit it?
The Copernican Principle
Humans do not occupy any special
place in the Universe.
We inhabit
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An ordinary planet
Orbiting an ordinary star
In the backwaters of the Milky Way
An ordinary galaxy
In an ordinary group of galaxies
In an ordinary super-cluster of galaxies
Are we insignificant?
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Individually, perhaps
BUT… will humans colonize the stars?
Will we exploit the Galaxy’s resources?
The role of the observer in quantum
mechanics
• Does human thought collapse the wave
function?
• We are part of the strange loop of
Nature.
The Future
• We face a catastrophe (war, plague,
starvation).
• We learn to live in harmony with our
planet.
• We move into space and colonize the
Galaxy.
Are humans alone?
• Nothing particularly special about Earth
• Life may well exist on other planets
• If their civilization got a head start, they
may well have already colonized the
Milky Way
• If so, where are they?
• We are looking!
Why are you here?
• Science is a key part of society.
• Stimulates technology.
• Provides the crucial knowledge for
social and ethical decisions.
• Humans are a curious species, and
science provides answers.
Scientific Social Issues
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Extermination of species
Organ transplants
Cloning
Nuclear power and weapons
Overpopulation
Use of outer space
Global warming
Ozone depletion
Where do you find science?
Just open your eyes,
and look around.
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