SlideShare a Scribd company logo
1 of 30
Sean Carroll
California Institute of Technology
Science and philosophy have changed
our image of the world
Our everyday, common-sense way of thinking about
the world (the “manifest image”) has not caught up.
Manifest image Scientific image
Time flows from past Time is a label within
to future an eternal universe
For every event there is Parts of the
universe
a reason; for every are related by patterns:
effect there is a cause the laws of nature
Life and mind are Life and mind are
distinct from matter physical and emergent
Purpose, morality, and Purpose, morality and
meaning are objective meaning are
personal
Ontology:
the study of being,
what exists
Reality
Monism
multiple one
Idealism
nature mind
Naturalism
Property
dualism
Physicalism
extra-
physical physical
Austere
naturalism
Poetic
naturalism
eliminative expansive
Poetic Naturalism
• There is only one world, the natural world.
• We learn about it empirically, through science.
• But there are many ways of talking about the world.
• If a way of talking accurately describes (part of)
the world, the concepts it refers to are real.
Our task: understand how the fundamental-physics
way of talking about the world is compatible with
the everyday-life way of talking about it.
[Allesandro Bianchi, Reuters]
Cause and effect, motion and movers,
reasons why
Everything that happens has a cause/reason?
Aristotle: Eric Gaba.
Aristotle Spinoza Leibniz
We learn about the world by looking at it
(not just by thinking about it)
Hume Bayes
Bayesian reasoning
posterior
credence
likelihood of
evidence given theory
prior
credence
“Credence” = “degree of belief.”
1) Assign priors.
2) Calculate likelihoods.
3) Gather evidence.
4) Update credences.
Steps:
Conservation of momentum:
the world moves by itself
Ibn Sina
Ibn Sina: Adam Jones; Voyager: NASA/JPL. Wikimedia commons.
“An intellect which at a certain moment would know all forces
and all positions of all items of which nature is composed…
for such an intellect nothing would be uncertain and the future
just like the past would be present before its eyes.”
- An Essay on Probabilities, 1814
Laplace’s Demon.
Laplace: Wikimedia Commons
Conservation of information:
each moment determines
its past and future
Laws are differential equations in time.
Isaac Newton:
Erwin Schrödinger:
(Footnote: quantum indeterminism?)
Time doesn’t “flow,”
or bring the future
into existence; it’s
just a label.
Laws of nature are
patterns connecting
different moments.
time
“Cause and effect” isn’t fundamental
“The law of causality, I believe,
like much that passes
muster among philosophers,
is a relic of a bygone age,
surviving, like the monarchy,
only because it is erroneously
supposed to do no harm.”
– Bertrand Russell
Aging Memory
Cause & EffectFree Will
Major disconnect between fundamental physics
and everyday life: the arrow of time.
Nowhere to be found in the underlying, microscopic laws.
A single phenomenon underlies all
manifestations of time’s arrow: increasing entropy.
Entropy is a measure of disorderliness,
messiness, randomness.
Time
Entropy
Second Law of Thermodynamics:
entropy increases with time
(in closed systems).
Ludwig Boltzmann, 1870’s:
Entropy counts the number
of ways we can re-arrange
a system without changing
its basic appearance.
high entropy:
all mixed up
low entropy:
delicately
ordered
[Martin Röll]
possible arrangements
of atoms/molecules,
grouped by macroscopic
indistinguishability
Entropy increases
simply because there
are more ways to
be high-entropy
than low-entropy.
All makes sense,
if the entropy was
low to begin with.
low
entropy
high
entropy
The Past Hypothesis:
our universe started in a low-entropy state.
13.8 billion years ago, at the Big Bang.
1 second: hot, smooth plasma.
380,000 years: ripples in a smooth background
[Planck]
1010
years: stars and galaxies.
1015
years: black holes and rocks.
10100
years: empty space (dark energy).
1 sec 105
yr 1010
yr 1015
yr 10100
yr
Our observable universe
“Memories” and “causes” are emergent features of
an underlying time-symmetric universe that has a
macroscopic arrow of time.
Memory: feature of now
that lets us infer something
about the past.
Cause: feature of now
that lets us infer something
about the future.
Low-entropy past gives
features of the present
leverage over other times.
what we know
about the present
low-entropy
past
correct reconstruction
possible
futures
possible
pasts
Emergence:
different levels of description involve
completely different concepts/vocabularies
Macroscopic world
Microscopic fundamental physics
tables
chairs
people
planets
particles
forces
spacetime
• arrow of time
• dissipation
• cause and effect
• “reasons why”
• laws of nature
• patterns
• differential equations
• conservation of
information
1. Cosmos, Time, Memory
images of the world; causality; the arrow of time
2. The Stuff of which We Are Made
quantum theory; the laws underlying everyday life
3. Layers of Reality
effective theories; emergence; multiple vocabularies
4. Simplicity, Complexity, Thought
entropy vs. complexity; life; consciousness
5. Our Place in the Universe
ought vs. is; meaning, caring, constructing morals

More Related Content

What's hot

General Relativity and Cosmology
General Relativity and CosmologyGeneral Relativity and Cosmology
General Relativity and CosmologyPratik Tarafdar
 
Setting Time Aright
Setting Time ArightSetting Time Aright
Setting Time ArightSean Carroll
 
Relativity theory project
Relativity theory project Relativity theory project
Relativity theory project Seergio Garcia
 
Chapter 17 Lecture
Chapter 17 LectureChapter 17 Lecture
Chapter 17 Lecturedlsupport
 
Einstein theory of time travel
Einstein theory of time travelEinstein theory of time travel
Einstein theory of time travelKumar
 
Is time travel possible?
Is time travel possible?Is time travel possible?
Is time travel possible?Salgi15
 
BLACK HOLE-THE OTHER DIMENSION
BLACK HOLE-THE OTHER DIMENSIONBLACK HOLE-THE OTHER DIMENSION
BLACK HOLE-THE OTHER DIMENSIONArkadeep Dey
 
The multi universe theory
The multi universe theoryThe multi universe theory
The multi universe theorystudent
 
The big bang theory
The big bang theoryThe big bang theory
The big bang theoryEsther020
 
Time travel
Time travelTime travel
Time travelhplap
 
Quantum entanglement
Quantum entanglementQuantum entanglement
Quantum entanglementAKM666
 
Dark matter & dark energy
Dark matter & dark energyDark matter & dark energy
Dark matter & dark energysurat murthy
 
D5 further cosmology
D5 further cosmologyD5 further cosmology
D5 further cosmologyPaula Mills
 
Quantum Field Theory and the Limits of Knowledge
Quantum Field Theory and the Limits of KnowledgeQuantum Field Theory and the Limits of Knowledge
Quantum Field Theory and the Limits of KnowledgeSean Carroll
 

What's hot (20)

General Relativity and Cosmology
General Relativity and CosmologyGeneral Relativity and Cosmology
General Relativity and Cosmology
 
Setting Time Aright
Setting Time ArightSetting Time Aright
Setting Time Aright
 
Relativity theory project
Relativity theory project Relativity theory project
Relativity theory project
 
Chapter 17 Lecture
Chapter 17 LectureChapter 17 Lecture
Chapter 17 Lecture
 
Einstein theory of time travel
Einstein theory of time travelEinstein theory of time travel
Einstein theory of time travel
 
Time travel
Time travelTime travel
Time travel
 
Time Travel
Time Travel Time Travel
Time Travel
 
Is time travel possible?
Is time travel possible?Is time travel possible?
Is time travel possible?
 
BLACK HOLE-THE OTHER DIMENSION
BLACK HOLE-THE OTHER DIMENSIONBLACK HOLE-THE OTHER DIMENSION
BLACK HOLE-THE OTHER DIMENSION
 
The multi universe theory
The multi universe theoryThe multi universe theory
The multi universe theory
 
Cosmology,bigbang and dark energy
Cosmology,bigbang and dark energyCosmology,bigbang and dark energy
Cosmology,bigbang and dark energy
 
Wormholes and Hyperspace
Wormholes and HyperspaceWormholes and Hyperspace
Wormholes and Hyperspace
 
The big bang theory
The big bang theoryThe big bang theory
The big bang theory
 
Time travel
Time travelTime travel
Time travel
 
Parallel universes
Parallel universesParallel universes
Parallel universes
 
Quantum entanglement
Quantum entanglementQuantum entanglement
Quantum entanglement
 
Dark matter & dark energy
Dark matter & dark energyDark matter & dark energy
Dark matter & dark energy
 
Time travel
Time travel Time travel
Time travel
 
D5 further cosmology
D5 further cosmologyD5 further cosmology
D5 further cosmology
 
Quantum Field Theory and the Limits of Knowledge
Quantum Field Theory and the Limits of KnowledgeQuantum Field Theory and the Limits of Knowledge
Quantum Field Theory and the Limits of Knowledge
 

Similar to Gifford Lecture One: Cosmos, Time, Memory

Purpose and the Universe
Purpose and the UniversePurpose and the Universe
Purpose and the UniverseSean Carroll
 
Jack sarfattisavile041915v3
Jack sarfattisavile041915v3Jack sarfattisavile041915v3
Jack sarfattisavile041915v3Elsa von Licy
 
Active information in quantum physics, biology and beyond. Argumenta lecture
Active information in quantum physics, biology and beyond. Argumenta lectureActive information in quantum physics, biology and beyond. Argumenta lecture
Active information in quantum physics, biology and beyond. Argumenta lectureGenes and Society Argumenta Project
 
Examples Of Disagree
Examples Of DisagreeExamples Of Disagree
Examples Of DisagreeMelissa Dudas
 
DxF2009, Utrecht: "All the time in the world"
DxF2009, Utrecht: "All the time in the world"DxF2009, Utrecht: "All the time in the world"
DxF2009, Utrecht: "All the time in the world"Matt Jones
 
Financial Engineering and Its Discontents by Emanuel Derman at QuantCon 2016
Financial Engineering and Its Discontents by Emanuel Derman at QuantCon 2016Financial Engineering and Its Discontents by Emanuel Derman at QuantCon 2016
Financial Engineering and Its Discontents by Emanuel Derman at QuantCon 2016Quantopian
 
MULTIVERSE - Rabbil - 'Alamin
MULTIVERSE -  Rabbil - 'Alamin MULTIVERSE -  Rabbil - 'Alamin
MULTIVERSE - Rabbil - 'Alamin Asgar Fakhrudin
 
Teleological Argument
Teleological ArgumentTeleological Argument
Teleological Argumentmrhartley
 
Teleological argument
Teleological argumentTeleological argument
Teleological argumentmrhartley
 
The Quantum Mind: Panpsychism, Physics, and Consciousness
The Quantum Mind: Panpsychism, Physics, and ConsciousnessThe Quantum Mind: Panpsychism, Physics, and Consciousness
The Quantum Mind: Panpsychism, Physics, and ConsciousnessJed Stamas
 
Durée Réelle : microphysical indetermination : creative emergence
Durée Réelle : microphysical indetermination : creative emergenceDurée Réelle : microphysical indetermination : creative emergence
Durée Réelle : microphysical indetermination : creative emergenceDavid Kreps
 
Conference Etpa Timisoara English Version
Conference Etpa Timisoara  English VersionConference Etpa Timisoara  English Version
Conference Etpa Timisoara English Versionguest688b9a8
 
Short Essay On Money CanT Buy Happiness. Online assignment writing service.
Short Essay On Money CanT Buy Happiness. Online assignment writing service.Short Essay On Money CanT Buy Happiness. Online assignment writing service.
Short Essay On Money CanT Buy Happiness. Online assignment writing service.Heidi Wilson
 
From Reductionism to Emergence: Transcending Death During COVID-19
From Reductionism to Emergence: Transcending Death During COVID-19From Reductionism to Emergence: Transcending Death During COVID-19
From Reductionism to Emergence: Transcending Death During COVID-19Paul H. Carr
 
From the Beginning of Space and Time: Modern Science and the Mystic Universe
From the Beginning of Space and Time: Modern Science and the Mystic UniverseFrom the Beginning of Space and Time: Modern Science and the Mystic Universe
From the Beginning of Space and Time: Modern Science and the Mystic UniverseManjunath.R -
 
Physics and Indian Spiritual Tradition - Giulio Prisco.pdf
Physics and Indian Spiritual Tradition - Giulio Prisco.pdfPhysics and Indian Spiritual Tradition - Giulio Prisco.pdf
Physics and Indian Spiritual Tradition - Giulio Prisco.pdfGiulio Prisco
 
Return of God Hypothesis
Return of God HypothesisReturn of God Hypothesis
Return of God HypothesisAlan Haller
 

Similar to Gifford Lecture One: Cosmos, Time, Memory (20)

Purpose and the Universe
Purpose and the UniversePurpose and the Universe
Purpose and the Universe
 
Jack sarfattisavile041915v3
Jack sarfattisavile041915v3Jack sarfattisavile041915v3
Jack sarfattisavile041915v3
 
How the Universe Works.pptx
How the Universe Works.pptxHow the Universe Works.pptx
How the Universe Works.pptx
 
Active information in quantum physics, biology and beyond. Argumenta lecture
Active information in quantum physics, biology and beyond. Argumenta lectureActive information in quantum physics, biology and beyond. Argumenta lecture
Active information in quantum physics, biology and beyond. Argumenta lecture
 
Examples Of Disagree
Examples Of DisagreeExamples Of Disagree
Examples Of Disagree
 
DxF2009, Utrecht: "All the time in the world"
DxF2009, Utrecht: "All the time in the world"DxF2009, Utrecht: "All the time in the world"
DxF2009, Utrecht: "All the time in the world"
 
Anthropic cosmological principles
Anthropic cosmological principlesAnthropic cosmological principles
Anthropic cosmological principles
 
Newton
NewtonNewton
Newton
 
Financial Engineering and Its Discontents by Emanuel Derman at QuantCon 2016
Financial Engineering and Its Discontents by Emanuel Derman at QuantCon 2016Financial Engineering and Its Discontents by Emanuel Derman at QuantCon 2016
Financial Engineering and Its Discontents by Emanuel Derman at QuantCon 2016
 
MULTIVERSE - Rabbil - 'Alamin
MULTIVERSE -  Rabbil - 'Alamin MULTIVERSE -  Rabbil - 'Alamin
MULTIVERSE - Rabbil - 'Alamin
 
Teleological Argument
Teleological ArgumentTeleological Argument
Teleological Argument
 
Teleological argument
Teleological argumentTeleological argument
Teleological argument
 
The Quantum Mind: Panpsychism, Physics, and Consciousness
The Quantum Mind: Panpsychism, Physics, and ConsciousnessThe Quantum Mind: Panpsychism, Physics, and Consciousness
The Quantum Mind: Panpsychism, Physics, and Consciousness
 
Durée Réelle : microphysical indetermination : creative emergence
Durée Réelle : microphysical indetermination : creative emergenceDurée Réelle : microphysical indetermination : creative emergence
Durée Réelle : microphysical indetermination : creative emergence
 
Conference Etpa Timisoara English Version
Conference Etpa Timisoara  English VersionConference Etpa Timisoara  English Version
Conference Etpa Timisoara English Version
 
Short Essay On Money CanT Buy Happiness. Online assignment writing service.
Short Essay On Money CanT Buy Happiness. Online assignment writing service.Short Essay On Money CanT Buy Happiness. Online assignment writing service.
Short Essay On Money CanT Buy Happiness. Online assignment writing service.
 
From Reductionism to Emergence: Transcending Death During COVID-19
From Reductionism to Emergence: Transcending Death During COVID-19From Reductionism to Emergence: Transcending Death During COVID-19
From Reductionism to Emergence: Transcending Death During COVID-19
 
From the Beginning of Space and Time: Modern Science and the Mystic Universe
From the Beginning of Space and Time: Modern Science and the Mystic UniverseFrom the Beginning of Space and Time: Modern Science and the Mystic Universe
From the Beginning of Space and Time: Modern Science and the Mystic Universe
 
Physics and Indian Spiritual Tradition - Giulio Prisco.pdf
Physics and Indian Spiritual Tradition - Giulio Prisco.pdfPhysics and Indian Spiritual Tradition - Giulio Prisco.pdf
Physics and Indian Spiritual Tradition - Giulio Prisco.pdf
 
Return of God Hypothesis
Return of God HypothesisReturn of God Hypothesis
Return of God Hypothesis
 

Recently uploaded

Dubai Calls Girl Lisa O525547819 Lexi Call Girls In Dubai
Dubai Calls Girl Lisa O525547819 Lexi Call Girls In DubaiDubai Calls Girl Lisa O525547819 Lexi Call Girls In Dubai
Dubai Calls Girl Lisa O525547819 Lexi Call Girls In Dubaikojalkojal131
 
Call Girls in Majnu Ka Tilla Delhi 🔝9711014705🔝 Genuine
Call Girls in Majnu Ka Tilla Delhi 🔝9711014705🔝 GenuineCall Girls in Majnu Ka Tilla Delhi 🔝9711014705🔝 Genuine
Call Girls in Majnu Ka Tilla Delhi 🔝9711014705🔝 Genuinethapagita
 
Fertilization: Sperm and the egg—collectively called the gametes—fuse togethe...
Fertilization: Sperm and the egg—collectively called the gametes—fuse togethe...Fertilization: Sperm and the egg—collectively called the gametes—fuse togethe...
Fertilization: Sperm and the egg—collectively called the gametes—fuse togethe...D. B. S. College Kanpur
 
Citronella presentation SlideShare mani upadhyay
Citronella presentation SlideShare mani upadhyayCitronella presentation SlideShare mani upadhyay
Citronella presentation SlideShare mani upadhyayupadhyaymani499
 
REVISTA DE BIOLOGIA E CIÊNCIAS DA TERRA ISSN 1519-5228 - Artigo_Bioterra_V24_...
REVISTA DE BIOLOGIA E CIÊNCIAS DA TERRA ISSN 1519-5228 - Artigo_Bioterra_V24_...REVISTA DE BIOLOGIA E CIÊNCIAS DA TERRA ISSN 1519-5228 - Artigo_Bioterra_V24_...
REVISTA DE BIOLOGIA E CIÊNCIAS DA TERRA ISSN 1519-5228 - Artigo_Bioterra_V24_...Universidade Federal de Sergipe - UFS
 
《Queensland毕业文凭-昆士兰大学毕业证成绩单》
《Queensland毕业文凭-昆士兰大学毕业证成绩单》《Queensland毕业文凭-昆士兰大学毕业证成绩单》
《Queensland毕业文凭-昆士兰大学毕业证成绩单》rnrncn29
 
办理麦克马斯特大学毕业证成绩单|购买加拿大文凭证书
办理麦克马斯特大学毕业证成绩单|购买加拿大文凭证书办理麦克马斯特大学毕业证成绩单|购买加拿大文凭证书
办理麦克马斯特大学毕业证成绩单|购买加拿大文凭证书zdzoqco
 
Pests of castor_Binomics_Identification_Dr.UPR.pdf
Pests of castor_Binomics_Identification_Dr.UPR.pdfPests of castor_Binomics_Identification_Dr.UPR.pdf
Pests of castor_Binomics_Identification_Dr.UPR.pdfPirithiRaju
 
Pests of Bengal gram_Identification_Dr.UPR.pdf
Pests of Bengal gram_Identification_Dr.UPR.pdfPests of Bengal gram_Identification_Dr.UPR.pdf
Pests of Bengal gram_Identification_Dr.UPR.pdfPirithiRaju
 
PROJECTILE MOTION-Horizontal and Vertical
PROJECTILE MOTION-Horizontal and VerticalPROJECTILE MOTION-Horizontal and Vertical
PROJECTILE MOTION-Horizontal and VerticalMAESTRELLAMesa2
 
Manassas R - Parkside Middle School 🌎🏫
Manassas R - Parkside Middle School 🌎🏫Manassas R - Parkside Middle School 🌎🏫
Manassas R - Parkside Middle School 🌎🏫qfactory1
 
Servosystem Theory / Cybernetic Theory by Petrovic
Servosystem Theory / Cybernetic Theory by PetrovicServosystem Theory / Cybernetic Theory by Petrovic
Servosystem Theory / Cybernetic Theory by PetrovicAditi Jain
 
trihybrid cross , test cross chi squares
trihybrid cross , test cross chi squarestrihybrid cross , test cross chi squares
trihybrid cross , test cross chi squaresusmanzain586
 
Pests of Blackgram, greengram, cowpea_Dr.UPR.pdf
Pests of Blackgram, greengram, cowpea_Dr.UPR.pdfPests of Blackgram, greengram, cowpea_Dr.UPR.pdf
Pests of Blackgram, greengram, cowpea_Dr.UPR.pdfPirithiRaju
 
well logging & petrophysical analysis.pptx
well logging & petrophysical analysis.pptxwell logging & petrophysical analysis.pptx
well logging & petrophysical analysis.pptxzaydmeerab121
 
REVISTA DE BIOLOGIA E CIÊNCIAS DA TERRA ISSN 1519-5228 - Artigo_Bioterra_V24_...
REVISTA DE BIOLOGIA E CIÊNCIAS DA TERRA ISSN 1519-5228 - Artigo_Bioterra_V24_...REVISTA DE BIOLOGIA E CIÊNCIAS DA TERRA ISSN 1519-5228 - Artigo_Bioterra_V24_...
REVISTA DE BIOLOGIA E CIÊNCIAS DA TERRA ISSN 1519-5228 - Artigo_Bioterra_V24_...Universidade Federal de Sergipe - UFS
 
final waves properties grade 7 - third quarter
final waves properties grade 7 - third quarterfinal waves properties grade 7 - third quarter
final waves properties grade 7 - third quarterHanHyoKim
 
Thermodynamics ,types of system,formulae ,gibbs free energy .pptx
Thermodynamics ,types of system,formulae ,gibbs free energy .pptxThermodynamics ,types of system,formulae ,gibbs free energy .pptx
Thermodynamics ,types of system,formulae ,gibbs free energy .pptxuniversity
 

Recently uploaded (20)

Dubai Calls Girl Lisa O525547819 Lexi Call Girls In Dubai
Dubai Calls Girl Lisa O525547819 Lexi Call Girls In DubaiDubai Calls Girl Lisa O525547819 Lexi Call Girls In Dubai
Dubai Calls Girl Lisa O525547819 Lexi Call Girls In Dubai
 
Call Girls in Majnu Ka Tilla Delhi 🔝9711014705🔝 Genuine
Call Girls in Majnu Ka Tilla Delhi 🔝9711014705🔝 GenuineCall Girls in Majnu Ka Tilla Delhi 🔝9711014705🔝 Genuine
Call Girls in Majnu Ka Tilla Delhi 🔝9711014705🔝 Genuine
 
Fertilization: Sperm and the egg—collectively called the gametes—fuse togethe...
Fertilization: Sperm and the egg—collectively called the gametes—fuse togethe...Fertilization: Sperm and the egg—collectively called the gametes—fuse togethe...
Fertilization: Sperm and the egg—collectively called the gametes—fuse togethe...
 
Citronella presentation SlideShare mani upadhyay
Citronella presentation SlideShare mani upadhyayCitronella presentation SlideShare mani upadhyay
Citronella presentation SlideShare mani upadhyay
 
REVISTA DE BIOLOGIA E CIÊNCIAS DA TERRA ISSN 1519-5228 - Artigo_Bioterra_V24_...
REVISTA DE BIOLOGIA E CIÊNCIAS DA TERRA ISSN 1519-5228 - Artigo_Bioterra_V24_...REVISTA DE BIOLOGIA E CIÊNCIAS DA TERRA ISSN 1519-5228 - Artigo_Bioterra_V24_...
REVISTA DE BIOLOGIA E CIÊNCIAS DA TERRA ISSN 1519-5228 - Artigo_Bioterra_V24_...
 
《Queensland毕业文凭-昆士兰大学毕业证成绩单》
《Queensland毕业文凭-昆士兰大学毕业证成绩单》《Queensland毕业文凭-昆士兰大学毕业证成绩单》
《Queensland毕业文凭-昆士兰大学毕业证成绩单》
 
办理麦克马斯特大学毕业证成绩单|购买加拿大文凭证书
办理麦克马斯特大学毕业证成绩单|购买加拿大文凭证书办理麦克马斯特大学毕业证成绩单|购买加拿大文凭证书
办理麦克马斯特大学毕业证成绩单|购买加拿大文凭证书
 
Pests of castor_Binomics_Identification_Dr.UPR.pdf
Pests of castor_Binomics_Identification_Dr.UPR.pdfPests of castor_Binomics_Identification_Dr.UPR.pdf
Pests of castor_Binomics_Identification_Dr.UPR.pdf
 
PLASMODIUM. PPTX
PLASMODIUM. PPTXPLASMODIUM. PPTX
PLASMODIUM. PPTX
 
Pests of Bengal gram_Identification_Dr.UPR.pdf
Pests of Bengal gram_Identification_Dr.UPR.pdfPests of Bengal gram_Identification_Dr.UPR.pdf
Pests of Bengal gram_Identification_Dr.UPR.pdf
 
PROJECTILE MOTION-Horizontal and Vertical
PROJECTILE MOTION-Horizontal and VerticalPROJECTILE MOTION-Horizontal and Vertical
PROJECTILE MOTION-Horizontal and Vertical
 
Manassas R - Parkside Middle School 🌎🏫
Manassas R - Parkside Middle School 🌎🏫Manassas R - Parkside Middle School 🌎🏫
Manassas R - Parkside Middle School 🌎🏫
 
Servosystem Theory / Cybernetic Theory by Petrovic
Servosystem Theory / Cybernetic Theory by PetrovicServosystem Theory / Cybernetic Theory by Petrovic
Servosystem Theory / Cybernetic Theory by Petrovic
 
trihybrid cross , test cross chi squares
trihybrid cross , test cross chi squarestrihybrid cross , test cross chi squares
trihybrid cross , test cross chi squares
 
Pests of Blackgram, greengram, cowpea_Dr.UPR.pdf
Pests of Blackgram, greengram, cowpea_Dr.UPR.pdfPests of Blackgram, greengram, cowpea_Dr.UPR.pdf
Pests of Blackgram, greengram, cowpea_Dr.UPR.pdf
 
well logging & petrophysical analysis.pptx
well logging & petrophysical analysis.pptxwell logging & petrophysical analysis.pptx
well logging & petrophysical analysis.pptx
 
REVISTA DE BIOLOGIA E CIÊNCIAS DA TERRA ISSN 1519-5228 - Artigo_Bioterra_V24_...
REVISTA DE BIOLOGIA E CIÊNCIAS DA TERRA ISSN 1519-5228 - Artigo_Bioterra_V24_...REVISTA DE BIOLOGIA E CIÊNCIAS DA TERRA ISSN 1519-5228 - Artigo_Bioterra_V24_...
REVISTA DE BIOLOGIA E CIÊNCIAS DA TERRA ISSN 1519-5228 - Artigo_Bioterra_V24_...
 
Interferons.pptx.
Interferons.pptx.Interferons.pptx.
Interferons.pptx.
 
final waves properties grade 7 - third quarter
final waves properties grade 7 - third quarterfinal waves properties grade 7 - third quarter
final waves properties grade 7 - third quarter
 
Thermodynamics ,types of system,formulae ,gibbs free energy .pptx
Thermodynamics ,types of system,formulae ,gibbs free energy .pptxThermodynamics ,types of system,formulae ,gibbs free energy .pptx
Thermodynamics ,types of system,formulae ,gibbs free energy .pptx
 

Gifford Lecture One: Cosmos, Time, Memory

  • 2. Science and philosophy have changed our image of the world Our everyday, common-sense way of thinking about the world (the “manifest image”) has not caught up.
  • 3. Manifest image Scientific image Time flows from past Time is a label within to future an eternal universe For every event there is Parts of the universe a reason; for every are related by patterns: effect there is a cause the laws of nature Life and mind are Life and mind are distinct from matter physical and emergent Purpose, morality, and Purpose, morality and meaning are objective meaning are personal
  • 4. Ontology: the study of being, what exists Reality Monism multiple one Idealism nature mind Naturalism Property dualism Physicalism extra- physical physical Austere naturalism Poetic naturalism eliminative expansive
  • 5. Poetic Naturalism • There is only one world, the natural world. • We learn about it empirically, through science. • But there are many ways of talking about the world. • If a way of talking accurately describes (part of) the world, the concepts it refers to are real. Our task: understand how the fundamental-physics way of talking about the world is compatible with the everyday-life way of talking about it.
  • 6. [Allesandro Bianchi, Reuters] Cause and effect, motion and movers, reasons why
  • 7. Everything that happens has a cause/reason? Aristotle: Eric Gaba. Aristotle Spinoza Leibniz
  • 8. We learn about the world by looking at it (not just by thinking about it) Hume Bayes
  • 9. Bayesian reasoning posterior credence likelihood of evidence given theory prior credence “Credence” = “degree of belief.” 1) Assign priors. 2) Calculate likelihoods. 3) Gather evidence. 4) Update credences. Steps:
  • 10. Conservation of momentum: the world moves by itself Ibn Sina Ibn Sina: Adam Jones; Voyager: NASA/JPL. Wikimedia commons.
  • 11. “An intellect which at a certain moment would know all forces and all positions of all items of which nature is composed… for such an intellect nothing would be uncertain and the future just like the past would be present before its eyes.” - An Essay on Probabilities, 1814 Laplace’s Demon. Laplace: Wikimedia Commons Conservation of information: each moment determines its past and future
  • 12. Laws are differential equations in time. Isaac Newton: Erwin Schrödinger: (Footnote: quantum indeterminism?)
  • 13. Time doesn’t “flow,” or bring the future into existence; it’s just a label. Laws of nature are patterns connecting different moments. time
  • 14. “Cause and effect” isn’t fundamental “The law of causality, I believe, like much that passes muster among philosophers, is a relic of a bygone age, surviving, like the monarchy, only because it is erroneously supposed to do no harm.” – Bertrand Russell
  • 15. Aging Memory Cause & EffectFree Will Major disconnect between fundamental physics and everyday life: the arrow of time. Nowhere to be found in the underlying, microscopic laws.
  • 16. A single phenomenon underlies all manifestations of time’s arrow: increasing entropy. Entropy is a measure of disorderliness, messiness, randomness.
  • 17. Time Entropy Second Law of Thermodynamics: entropy increases with time (in closed systems).
  • 18. Ludwig Boltzmann, 1870’s: Entropy counts the number of ways we can re-arrange a system without changing its basic appearance. high entropy: all mixed up low entropy: delicately ordered [Martin Röll]
  • 19. possible arrangements of atoms/molecules, grouped by macroscopic indistinguishability Entropy increases simply because there are more ways to be high-entropy than low-entropy. All makes sense, if the entropy was low to begin with. low entropy high entropy
  • 20. The Past Hypothesis: our universe started in a low-entropy state. 13.8 billion years ago, at the Big Bang.
  • 21. 1 second: hot, smooth plasma.
  • 22. 380,000 years: ripples in a smooth background [Planck]
  • 25. 10100 years: empty space (dark energy).
  • 26. 1 sec 105 yr 1010 yr 1015 yr 10100 yr Our observable universe
  • 27. “Memories” and “causes” are emergent features of an underlying time-symmetric universe that has a macroscopic arrow of time. Memory: feature of now that lets us infer something about the past. Cause: feature of now that lets us infer something about the future.
  • 28. Low-entropy past gives features of the present leverage over other times. what we know about the present low-entropy past correct reconstruction possible futures possible pasts
  • 29. Emergence: different levels of description involve completely different concepts/vocabularies Macroscopic world Microscopic fundamental physics tables chairs people planets particles forces spacetime • arrow of time • dissipation • cause and effect • “reasons why” • laws of nature • patterns • differential equations • conservation of information
  • 30. 1. Cosmos, Time, Memory images of the world; causality; the arrow of time 2. The Stuff of which We Are Made quantum theory; the laws underlying everyday life 3. Layers of Reality effective theories; emergence; multiple vocabularies 4. Simplicity, Complexity, Thought entropy vs. complexity; life; consciousness 5. Our Place in the Universe ought vs. is; meaning, caring, constructing morals

Editor's Notes

  1. William James, Alfred North Whitehead, Hannah Arendt, Neils Bohr
  2. Final cause: the sake for which something happens or is done. Principle of Sufficient Reason: “Nothing is without a ground or reason why it is.”
  3. What do we do for the multiverse? Exactly this.