fundamental physics and the supernaturalfiles.meetup.com/7518042/fundamental physics and the big...

Fundamental Physics and the Big Questions

Ian Bryce, BSc (Physics), BE(Hons) [email protected]

www.hsnsw.asn.au

Presentation as at 3 October 2015

How science has answered or recast many of the famous questions of philosophy.

mailto:[email protected]

A: Traditional Questions about the Universe

B: Questions about Life and Mind

D: New questions which arise from science

E: Questions about Philosophy itself

What questions will we address?

C: Questions about The Spiritual and Ethics

Evidence

Answers

Question

Analysis

Our basic method

What questions will we address?

• What makes the crops grow?

• Where did the universe come from?

• Is there a Purpose?

• How does the universe work?

• Where will the universe end up?

A: Questions about the Universe

Questions about Life

• Where did life come from?

• Where did humans come from?

• How does the mind work?

• Do we have Freewill?

• Is what happens in the universe predetermined?

• Is there a purpose to life?


C. About the Supernatural

• What is spirit? What is the soul?

• The Afterlife?

• Are there gods?

• How does prayer work?

• Angels and demons?

• Where do ethics come from?

• What are human rights?

• Animal rights?

C: Questions about the Spiritual and Ethics

• Quantum Mechanics

• The ultimate theory of physics?

• Dark Matter?

• Dark energy?

• The eventual fate of the universe?

• Is the universe infinite?

• Does it have an edge?

• Black Holes?

• Before the Big Bang?



• What is Philosophy? The application of pure thought to the solution of questions

• Can reason alone lead to any conclusion about the real world?

• Should it take into account the findings of science?

• What about Metaphysics?

Philosophers have debated such Big Questions for millennia.

• Many questions have been answered. • Some questions have been reformulated. • Some questions remain unanswered.

After going through the evidence, we will re-examine these mysteries.

But first, to set the scene…

When you travel…

Which method do you use?

IMMATERIAL

MATERIAL

When you communicate…

Which method do you use?

IMMATERIAL

MATERIAL

But hang on…This is showing a tension between spiritual beliefs and science.

Perhaps they can BOTH exist in harmony?

Relation between the immaterial (pseudoscience)

and the material (science)

“Science and religion are Non-overlapping

Magisteria”

– Steven J Gould

“There is a single light of science, and to brighten it anywhere is to brighten it everywhere.” - Isaac Asimov

It is called the scientific method.

• One method is far more effective than any other, in finding the truth.

• It has revealed the origins of the universe,

• of our planet,

• of life,

• and of humans.

The scientific method

Science combines two elements:

• Observation or testing (gathering evidence)

• Analysis (using known data and applying theory)

Also, philosophy helps us to place that knowledge in our intellectual framework.

A: Questions about the Universe

Where science comes from. Many researchers, many countries, hundreds of years, constant checks

The universe through time

Enlightenment through science Cosmology has revealed the beginning of the

universe

• The big bang

The first generation of stars

Formation of the Elements #1

1. Hydrogen (H) nucleus – protons – from the quark-gluon plasma, at about 3 minutes

Quark-gluon plasma cooling protons

Formation of the

elements #2

Inside stars

Heavier elements (more later)

As these nucleii cooled, they collected

electrons to form neutral atoms

29

• These atoms formed gas and dust.

• They drifted around in space, until they clumped together by gravity

Enlightenment through science • The clump grows,

and a new star forms at the center

Enlightenment through science

• The surrounding disk clumps into planets

Enlightenment through science • Leftover material clumped into: MOONS

Enlightenment through science • Leftover material clumped into: RINGS

Enlightenment through science • Leftover material clumped into: ASTEROIDS

Enlightenment through science • Leftover material clumped into: COMETS

When formed 4.5 billion years ago, the earth is molten rock

When it cools about 3.7 billion years ago, comets bring ice

For a video on comets, see https://www.youtube.com/watch?v=fGTq14qCwJk

Enlightenment through science • Conditions stabilize

Enlightenment through science • Life began, when a replicating molecule arose

• (no trace left now - possibly related to RNA )

Enlightenment through science • Fish and Reptiles evolved

Enlightenment through science • Then came Mammals

Enlightenment through science • Homonids

Enlightenment through science • And eventually Homo Sapiens - intelligent

Intelligent enough to (eventually) invent science

More on that next week…

What has science found out, at a fundamental

level?

Map of physics

Fundamental Physics

Standard Model of Particle Physics

Quantum Mechanics

General relativity

Elementary Particles

Quarks

Gluons, photons

Electrons etc

The four forces

Gravity

Electromagnetism

Weak interaction

Strong interaction

Compound particles

Proton

Neutron

Mesons etc

Atoms

Nucleus + electrons + QM

Molecules

Assemblies of atoms Matter

Complex assemblies of atoms and molecules

Other sciences

A map of physics © Ian Bryce 2014

Evolution of

the universe

These four forces account for everything we see happening in the universe (at the most fundamental level)

THERE ARE APPARENTLY NO GAPS

What about Quantum Mechanics?

Is there a bridge joining classical mechanics to quantum mechanics?

A: Classical Mechanics

Lagrangian

Eg orbiting body

L = T – V = ½ m v2 - GMm/r

Put L in a classical formula, solve,

gives classical motion of planet or electron

B: Quantum Mechanics

Same Lagrangian

Eg orbiting body

L = T – V = ½ m v2 - ɛQq/r

Put L in Schrodinger’s Equation, solve,

Gives quantum solution of atom

Quantum Mechanics Quantum

solution of a hydrogen

atom

Top left – ground state

Others – excited states

Excited states and light emission

Different atoms give different wavelengths (colors)

Light Sources demonstration

• Sun (black body 6000K)

• Candle, filament (black body 3000K)

• Salt in a candle – sodium (electron transition)

• LED (single color)

• LED (white)

• Laser (stimulated emission, single wavelength)

• Compact Flourescent (many discrete wavelengths)

These light sources cannot be explained in terms of classical physics. Quantum mechanics is required.

LED’s and TV’s

Quantum Molecules

Quantum Molecule - hydrogen

Quantum molecule - Electron Cloud Impossible to draw!

Stick models (easier to draw).

Caffeine!

Stick model. DNA.

Watson and

Crick

Quantum Molecule – DNA

Quantum Solids

Science has a good understanding of the universe,

and the matter in it. At least in the here and now.

How complete is science’s knowledge

of how the world works?

Narrative: Your car won’t start…

Your reactions illustrate that THERE ARE NO GAPS

IN HOW THE WORLD WORKS* *At least in the here and now

We have had a tour of science…

Now we can revisit some Big Questions…

Traditional Questions about the Universe

What makes the crops grow?

• Nutrients from the atmosphere

• Nutrients from the soil

• Water

• Sunlight

• Propagation by seeds, cuttings etc

ANSWERED BY SCIENCE


Where did the universe come from?

• Traced all the way back to the big bang at least 10-32 seconds)

• Its origin is still unknown (some theories later).

Largely answered.


How does the universe work?

• Mapped out by science

• New questions arise

LARGELY ANSWERED BY SCIENCE.


The ultimate fate of the universe?

• Laws of physics projected into the future

• An advanced topic

LARGELY ANSWERED BY SCIENCE.

End Part 1 – The Universe (Part 2 next week –Life and the Mind) Advanced topics available….





Where we are now


Where did the elements of life come from?

Or what is your body made from?

1. Hydrogen (H) nucleus – protons – from the quark-gluon plasma.

At Big Bang + 3 minutes

Quark-gluon plasma cooling protons

2. C, N, O nucleii

inside all stars.

200 M years to present.

3. Na, Mg, P, Cl, K, S in the first large stars, blown off in solar wind. 200 M years

4. Al, Si, Fe in a supernova (exploding star). 300 M years

Here is where they all came from

As these nucleii cooled, they collected

electrons to form neutral atoms

82

• These atoms formed gas and dust.

• They drifted around in space, until they clumped together by gravity

Enlightenment through science • The clump grows,

and a new star forms at the center


• The surrounding disk clumps into planets


• These elements were being modified by radioactive processes.

• They remained on earth until taken up by life.

Enlightenment through science • Meanwhile, on the new Earth, things stabilize

Enlightenment through science • Life began, when a replicating molecule arose

• (no trace left now - possibly related to RNA )

Enlightenment through science • Fish and Reptiles evolved

Enlightenment through science • Then came Mammals

Enlightenment through science • Homonids

Enlightenment through science • And eventually Homo Sapiens - intelligent

Intelligent enough to (eventually) invent science

Where does the mind fit in? A traditional view

Immaterial

realm

Material realm

94

Minds, souls, spirits

Planets, trees, humans

The car won’t start story… Your reactions illustrate that

THERE ARE NO GAPS IN HOW THE WORLD WORKS*

*At least in the here and now

Therefore:

Immaterial

realm.

Empty?

Material realm

Must include

everything,

material and

spiritual

“Spiritual” phenomena

are either:

• a layer of complexity

in the Material realm,

• Or do not exist!

96

If the universe is only material… How do we explain the Mind?

Layers of complexity:

What can science tell us?

Watch Prickles and goo Attached, or www.youtube.com/watch?v=XXi_ldNRNtM

At the fundamental level – things are pretty well sewn up – there are apparently no gaps… • At least since inflation • With some possible exceptions such as black holes • Some unidentified matter • Deeper levels of explanation might exist.

At higher levels of complexity – much is known, and much is unknown: • Eg the procrsses of life • The brain • Consciousness • An opera Lets look at some of these!

What has science told us about the brain?

Physics has shown that the brain

obeys

the Law of Conservation of

Mass

If you buy a lamb’s brain from the butcher…

What has science told us about the brain?

Physics has shown that the brain obeys

the Laws of Motion

What has science told us about the Brain?

Solving difficult mental problems burns calories!

Physics has shown that the brain obeys

the Law of Conservation of Energy.


Science has shown that the brain has

capabilities in proportion to its

size!

X-ray of Homer Simpson


The electrochemistry

is largely understood… at a fundamental

level


• THUS the brain obeys ALL the laws of physics

• Its operation is based on the four forces of nature.

What has science told us about the Mind?

The mind is what the brain does.

Your computer runs Applications

- Word, Excel, Google, printer, Skype etc.

Your brain runs your Mind

- your body, movement,

reads newspapers etc.


• Can a Mind exist, separately from a Brain?

• The fossil record…

• The record of fossil skulls shows that nature invested a lot in providing brains

• All sentient creatures possess a brain. • No sign at all of a mind without a brain. • ALL MINDS REQUIRE BRAINS!

• What happens if your brain is starved of oxygen?

• Of energy (ATP)? • You faint!

• ALL MINDS DEPEND TOTALLY

ON A PHYSICAL LIFE SUPPORT SYSTEM

• What happens if your brain is infused with alcohol?

• - Your Honour, I might have been over the 0.05% limit, but my mind is separate and was not affected.

• ALL MINDS ARE AT THE MERCY OF CHEMICALS!

Sentience - the capacity for Pleasure & Pain

(brain function)

– variation throughout a normal life

Sentience

age

birth

Conception

death

Nervous system forms © 2007 Ian Bryce

111

1

0

Sentience – the topic of a talk on Wed 14 Oct

2015, see Meetup - Open Forum Sydney

Sentience

age

birth

Conception

death

Nervous system forms © 2007 Ian Bryce

112

1

0

How does the mind interface with the world?

Inputs: senses Outputs: Motor functions

Optic nerves cross at the chiasm

How does the mind interface with the world?

The inputs and outputs can be reproduced by science


To communicate by other means • Intuition • Telepathy • Psychic abilities • Telekenesis • Prayer • Connection to an immaterial realm would require a new force in physics.


Thought

Science

Conscience

Prayer

Meditation

Admiration

Fear

Happiness

Hypnosis

Dreams

These are mental processes!

What are mental processes?

They are all internal brain functions!

They are layers of complexity – emergent properties

– of physical matter

What is known about the mind?

Fundamental level

• Prickly

• Well established

• Highly confident

Higher level of complexity

• Gooey

• A little is known

• Much to find out

• Emergent properties


Where did life come from?

• Natural physical processes

• The mechanism is NOT known

THIS MYSTERY SURVIVES!


Where did humans come from?

• Evolution from more primitive species

• Random mutations

• Natural selection

• Survival of the fittest

ANSWERED BY SCIENCE


How does the mind work?

(a) At a fundamental level:

Electrochemical processes

Obeys ALL the laws of physics, chemistry etc

ANSWERED BY SCIENCE


How does the mind work?

(b) At a higher level of complexity:

• Much is known…

• And much is not yet understood

• Research is constantly revealing more detail

• The mind emerges as higher levels of complexity.

IN PROGRESS





Where we are now


Prayer Many people believe they can communicate with an external being, separately from our normal senses…

Prayer

• Science theory shows that such communication would require a new effect in physics. • The Car wont start example illustrates that there

are no such gaps in physics. • Science experiment shows that prayer is

ineffective (untercessory prayer, historical data, and modern tests)

• So prayer is only internal to your brain

Conscience or Prayer

Imagined god

Desire for guidance

Prayer… a conversation between two brain functions?

Conscience or Prayer

Immediate needs

Ingrained moral rules

Conscience …

a conversation between two brain functions?

The Mind and Past Lives SCIENCE HAS SHOWN: The MIND is a function of the brain. The brain develops in the a fetus and in the a child Memories are created from experiences as a child and as an adult There is no mechanism for installing the memories from a different brain.

PAST LIVES ARE OUT!

The Mind and Afterlives SCIENCE HAS SHOWN: The MIND is a function of the brain. It is entirely dependent on physical support systems. When the body dies, the mind stops.

AFTERLIVES ARE OUT!

Questions about Ethics

Is what happens in the universe predetermined (ie fatalism)?

• Everything that happens is influenced by prior events

• There is also chance involved through quantum mechanics*

• Therefore NOT determined

• “God does play dice…”

• ANSWERED!

* most likely. One theory (De Broglie–Bohm) contains QM with underlying truths, which make the universe fixed since the big bang.

Questions about the Ethics

Do we have freewill? No “Yes or No” answer.

Recast the question: We experience a feeling of freewill. What is its mechanism?

• The mind operates at a fundamental level by the four known forces

• This includes decision making

• Our choices are influenced by our genes – genetic packages from our parents

• And memes – behaviour packages from society

• And chance

Freewill is the feeling we have, while our brain performs the operation of choosing

RECAST AND ANSWERED

Questions about Ethics Freewill is the feeling we have, while our brain performs the operation of choosing

A Big Question about life:

Where do morals come

from?

“Philosophers have been

debating it for 3000 years…”

134

1. Where do morals come from?

(a) In the tribal culture

Gods

Prophets Holy books

The People

135

Material

realm

Spiritual realm

136


(b) But a Problem has been revealed

by travel and communication

137

God #1

God #2

God #3

God #99

God #4

God #5

Where do morals come from?

(c) Enlightenment 1650+ Inspired by the new scientific findings

Spiritual realm

Empty?

Material realm

Everything

What possible

origin of morals

can we fit into

this?

138


(d) Post-Enlightenment thinkers

reject the supernatural

look to nature

use introspection

Duty for duty’s sake - Kant

Its good to do good – Holyoake?

We hold these truths to be self-evident - Declaration of Independence

- illustrates the failure of introspection…

139



Spiritual realm

Material realm

People believe its good

It IS good

Moral decisions

140



Like a self-

licking ice

cream!

141


(e) Modern science

Add interactions with others

One generation Next generation

Genes Packages of DNA passed from parents

Memes Packages of behaviour passed from parents and community

How

characteristics

(physical and

social) are

propagated

through time

Others in tribe

142

Material realm


(e) Modern science (evolution and

neuroscience) says:




How

characteristics

(physical and

social) are

propagated

through time

This behaviour can be described as “built-in”, instinct, or intuition

143

Material realm


Modern science has answered that.

Briefly: Evolution! Which means:

Variation plus survival of the fittest

© C. Darwin ~1850

• Applies to physical

characteristics and also

behaviour

• For humans and other

animals

144



A: Instinctive morality – from evolution

• Brain functions

• Genes (selfish and altruistic)

• Memes

• Developed by groups of animals and humans

• Have survival value

• Evolving

• No gods or holy books


Instinctive Morality - Continued

• No absolute systems of morals

• Can’t say “I’m right and you’re wrong”

• Some people and groups have morals we would regard as poor

• Examples?

• William on Struggle Street (SBS) – a very simple morality – “You got it, I take it.”

ANSWERED

A new source of morality

Humans now* have a

very active prefrontal

cortex * Homo Sapiens 200,000 years

• Allows detailed

reasoning

• Has provided

scientific knowledge

• Allows enhanced

moral decisions 147

An example of a morality

invented by humans

“Welfare of sentient beings”

Four words*

Rationale: Most common threads in moral

systems include the “golden rule” and concern

for others Why? Because they are aware, or conscious, and capable of experiencing pleasure and pain Their welfare is important to us. *This is the topic of a separate talk.

148


(e) Modern science:

Now add a new source of behaviour




How

characteristics

(physical and

social) are

propagated

through time

Scientific knowledge and analysis

Others in tribe

149

Questions about Ethics (continued)


B: Reason

• Brain functions

• Neocortex

• We are free to make up our own morals

• But we must live with the consequences!

ANSWERED


What are human rights?

• Arise through human NEEDS

• Physical needs include food, water, clothing, shelter, safety

• Psychological needs include freedom from oppression, forming relationships, setting goals

• If we respect other peoples feelings, we will recognise these rights

• ANSWERED!


What about animal rights?

• Animals also have needs

• Physical needs include food, water, shelter, safety

• Psychological needs include freedom from oppression, forming relationships, (less than humans)

• Animals generally have less sentience (capacity for pleasure and pain)

• So animals should have rights to suit their needs

• ANSWERED!

These slides may be downloaded from

http://www.meetup.com/Secular-Party-NSW/files/

Or email me [email protected]

New questions which arise

from science

Advanced Topics





Where we are now


• Elliptical vs circular and hyperbolic orbits

• The ultimate structure of reality?

• Evolution of the universe since the big bang?

• Dark Matter?

• New Horizons Mission to Pluto

• Does it have an edge and is it infinite?

• Is the universe curved?

• The eventual fate of the universe?

• The source of the big bang?

• Higher levels of brain function?

Some of these are answered in Advanced Topics

Some are addressed in other presentations.

New questions which arise from science (advanced topics)

How is science addressing these questions?

What are the best answers? We will now examine some

examples.

Elliptical vs circular

and hyperbolic orbits

Solve Newton’s equation of motion for a central gravitational force:

Conic Sections

The ultimate structure of reality? • Might there be a new force in physics?

• The search for the Higgs Boson – LHC – largest machine ever built

• Found a new particle, implying a new force field

• Does not interact with matter, under current conditions

• So cannot account for freewill, psychic phenomena etc.

Evolution of the universe since the

big bang?

The tools being used: • Telescopes (optical radio, IR) • Particle accelerators • Theory • Simulations

Dark matter?

• There is too much gravity in galaxies, therefore dark matter

• Gravitational lensing can map it • The hunt is on to identify it!

How is the solar system being explored?

New Horizons mission to Pluto

New Horizons

space probe to

Pluto

New Horizons space probe to Pluto

Note RTG on New Horizons. Why?

Does the universe have an edge?

Could there conceivably be a boundary where stars and galaxies stop?

Does the universe have an edge?

• This is simple. Astronomy has clearly established the Cosmological Principle:

• The universe is Homogeneous – same rules apply everywhere, and matter is uniform (on large scales)

• The universe is Isotropic – behaves the same in all directions

• If there was an edge, the laws and matter would be different there.

• The edge hypothesis is REJECTED.

Is the universe curved?

In Euclidean geometry (like a sheet of paper), parallel lines remain the same distance apart. But there are other possibilities. In our 3D universe, general relativity specifies the curvature of space:

General Relativity: Space is curved by

the presence of matter and energy…

On larger scales, with many objects, the curvature averages out…

Finally, as matter becomes uniform (a fluid), the curvature must

become uniform too. The causes of curvature (sources) are: • The total density (visible matter,

dark matter, and energy) • Possible dark energy (or cosmological

constant) • Any expansion rate (Hubble Constant)

Curvature?

This is the first Friedman equation. It gives the curvature constant k for an evolving universe (at each moment), in terms of the state of the universe.

Curvature?

The inputs are the physical parameters at a given moment in time: • The average density of matter (including galaxies and

the gaps between them) (both visible and dark matter)= 5 protons per cubic metre

• The Hubble constant (recession velocity per distance away, approx 1 / 14 billion years)

• Gravitational constant (accurately known) • The cosmological constant (dark energy or a basic

property of spacetime). • There are 3 possibilities for the curvature:


R = infinity: critical, Euclidean geometry, universe has no edge, infinite number of galaxies.

R < 0: open, hyperbolic space, universe has no edge. Parallel lines double their spacing in distance π/2 |R|. Infinite number of galaxies.

R > 0: circumference of a circle is smaller than Euclidean. Finite number of galaxies, but still no edge. Parallel lines meet at a distance π/2 R. If you travel in any direction, in principle you will return home! After travelling a distance 2 π R.


A. Direct measurement of the curvature

• Number of galaxies near and far • Size of galaxies near and far. These measures are only approximate, due to the reducing brightness and increasing age of distant objects. These suggest any curvature is small (<0.3) within the observable universe. i.e. |R| > 40 billion light years. You need not fear parallel lines meeting on your exam paper!

Cosmic Microwave Background (CMB) • Spectrum = black body. • Strength = 2.7K. • Ripples magnitude = 10-5 of average. • Ripples spectrum = ~ 1 degree.


Introduce one tool:


B. Indirect evidence for curvature (induction). • The CMB can be compared with the current

distribution of galaxies – suggests approximately flat. • Theories of the evolution of the cosmos, can correct

for the differences in age of bodies. • The Friedman equations – link curvature to matter

density and expansion. • Inflation theory – prefers a flat universe. Results - unclear to date.

What is the ultimate fate of the universe?

The main tools: • a simulation of the universe • combined with detailed observations of

redshifts.

The ultimate Fate of the universe?

• Friedmann equations – derived from general relativity assuming uniform matter distribution:

These yield the time evolution and geometry of the universe, given the three types of density, at any given reference epoch (usually the present). The second equation introduces pressure (like a gas). http://en.wikipedia.org/wiki/Friedmann_equations


The variables #1 are (for reference): a is the scale factor – the distance from Perseus cluster to Hydra cluster (for example), measured at a given time, compared to what it is NOW. Growing steadily. å is its rate of change, hence the expansion rate, at a given time. k is the curvature (unitless). c is the speed of light (constant).


The variables #2 are (for reference): ä is the acceleration (+ or -) in the expansion rate, and is the output of equation 2 (the dependent variable). G is the gravitational constant (really constant) ρ is the average density of matter and energy ~ 5 protons per cubic metre, whose gravity slows the acceleration ä p is the pressure of matter and radiation Λ is the Cosmological Constant, or Dark Energy density

What role does Dark

Energy play? It wins in the end, pushing the universe

apart, as gravity

weakens.


• Some of the variables can be observed directly. • Others are adjusted so that when the simulation

is run, the predictions best match real observations.

• The result is a universe which is not only expanding, but accelerating!

• Confident but not certain. Brian Schmidt, 2011 Nobel Prize in Physics


• Thus the universe will never collapse, but will go on expanding forever.

• Eventually the stars will exhaust their fuel, and everything will cool down – a heat death.

• Galaxy clusters will retain their size, but their separation will increase until others become invisible. If future astronomers exist then…

• They will think there are 54 galaxies in the universe (the current Local Group).

Or that is one scenario.


Map of the universe seen from the Milky Way in the year 1,000,000,000,000,000 (simplified)

A timeline of our ultimate fate

-13.8 B y: big bang

-4.6 B y: sun, planets

-3.3 B y: bombardment stopped

-3.1 B y: life started

-0.0002: our species

0: now

1 B y: sun gets too hot, we move?

4 B y: Milky Way collides with Andromeda

100 B y: other galaxy clusters recede, most stars get cold

100 Trillion years: other galaxy clusters have gone

196

Before the Big Bang

Before the Big Bang

A survey of hypotheses And the scant evidence.

Before the Big Bang

Inflationary Multiverse Prof Max Tegmark, MIT Inflation is continuously spawning universes. Prof Anthony Aguirre, UCal Bubbles form, spawn U’s with different properties, different laws, different forces, different no. dimensions, different physics classes.

At bottom right – inflation

continuously spawning new

universes!

Before the Big Bang

Bump from next universe Prof Laura Mersini-Houghton - U N. Carolina String theory and QM. Wave Function of the universe is travelling over the landscape of quantum fluctuations. Some energy got trapped in a well. Inflated to become our universe. Other energy got trapped on other wells, became other universes. Different sizes, different properties? This hypothesis predicts, that where two universes were being spawned nearby, the gravitational pull disturbed the uniform matter, causing dark spots 10 degrees wide in CMB. Observed – next slide.

Before the Big Bang

Cosmic Microwave Background. Spectrum = black body. Strength = 2.7K. Ripples magnitude = 10-5 of average. Ripples spectrum = ~ 1 degree.

Before the Big Bang

Infinite patchwork multiverse Prof Max Tegmark, MIT • Our (visible) universe 10^80 particles, so there are

a finite no of arrangements. • But if infinite universes, then must be others the

same as ours! • An identical You must be in another. • And also variations of you, dressed differently,

married differently… • Laws the same, different history classes.

Before the Big Bang

Hilbert Space or Forking paths. Prof Seth Lloyd, MIT. Always laughing. • If I toss a coin, the universe splits into two copies. • They never recombine. • There have been ~10^120 decisions so far in this

universe. So there must be ~2^10^120 possible universes.

This hypothesis does not seem to make any testable predictions.

Before the Big Bang

Many Worlds interpretation of Quantum Mechanics Eg electron in double slit experiment. The electron seems to pass through both slits, so it can superimpose at the screen…

Before the Big Bang

The world splits. In A, the electron goes through slit 1. In B, it passes through slit 2. When measurement occurs, worlds A and B recombine, providing the required superposition. Nothing testable here – just an interpretation of conventional quantum mechanics.

Before the Big Bang

Chain of universes. Universes give rise to similar progeny. • When a black hole forms in our universe, the density and

temperature go to infinity. This is called a singularity. • The laws of physics break down, and must change into

different laws…

Before the Big Bang

…Chain of universes. This could conceivably spawn a new big bang, with its separate spacetime. Prof Robert Mann, Perimeter Institute Has a variation on this idea, where black holes in 4 dimensional universes generate a 3 D event horizon,, which became our universe.

So be careful when pulling the bath plug! Who knows where you might end up?

Before the Big Bang

Lava lamp hypothesis as a universe generator My own concept - Ian Bryce

Before the Big Bang

Lava lamp hypothesis as a universe generator #1 My reasoning goes like this: • Something (call it the motherverse) caused the Big

Bang and hence spawned our universe. • Our universe (with its known spacetime and state

laws) is not observed to spawn new universes*. Therefore, the motherverse must have (or have had) different laws of physics. Call them Federal laws.

*Possible exception: when a black hole collapses.

Before the Big Bang

Lava lamp hypothesis as a universe generator #2 • If we try to retrace our timeline, we come to a

stop* at the BB. Our space and time is not connected to anything else.

• Therefore, the motherverse had a different type of time.

• The anthropic principle suggests that there are many universes, with different physical constants.

• Therefore we need a universe generator which continuously spawns daughter universes, with differences. Possibly chaotic.

*Time becomes imaginary, according to some.

Before the Big Bang

Lava lamp hypothesis as a universe generator #3 • Ockhams Razor suggests that a

motherverse with simple properties is more likely than one with complex properties.

• I have a device which seems to demonstrate many of these properties.

• Lava lamp!

Before the Big Bang

Lava lamp hypothesis as a universe generator How does it fit the desired universe generator? #1 • Continuously spawns bubbles of wax - new

universes. • The bubbles are varying diameters, which

would cause different surface tension. • This would vary the apparent constants of

physics in the different bubbles • If they were universes, this variation might

allow life in at least some.

Before the Big Bang

Lava lamp hypothesis as a universe generator How does it fit the desired universe generator? #2 • Retracing the timeline of a ball of lava, leads to a time

when it was melting – different laws – and then was solid – time stops.

• Retracing the timeline of our universe, leads to the inflation period when the laws were different, and then time stops.

• The static solid wax (motherverse) has very simple laws, compared to the liquid bubbles where lots can happen - emergent properties

• This idea could direct the search for a hypothetical precursor to the Big Bang.

Testing before the Big Bang

How can a hypothesis about before the big bang be tested? We can’t see back past the BB directly. • But any hypothesised motherverse must have given rise to

our universe, with the laws and constants we have now.

• Its predictions can be tested against surviving evidence: • The cosmic microwave background temperature • The spectrum and distribution of ripples in the CMB • The distribution of matter • Possibly gravity waves from the very early universe.

So hypotheses can be tested (to some extent) by induction!

Possible gravity waves from an extreme current event (binary pulsar).

Possible gravity waves from an extreme early event (quantum fluctuations in inflation).

Summary: We have seen many ideas of what happened

before the Big Bang. I have put forward some ideas of my

own.

Higher levels of brain function?

Being investigated by:

• Optogenetics – make neurons fire when illuminated

• Fine imaging – trace the individual neurons

• Functional imaging – while a live brain in thinking

Higher levels of brain function?

The location of most functions has been identified

The Material vs the Spiritual

Are religion and science compatible beliefs? Some statistics I have found.

The Material vs the Spiritual #1 Worldwide, there is a clear decrease in belief with level of education.

Of course, in many countries, even scientists would not dare to report their disbelief. So the real case must be even stronger…

The Material vs the Spiritual #2 In the USA, where there is greater freedom of speech,

the reported non-belief increases very dramatically with education in science.

The Material vs the Spiritual #3 Over the last century, belief in a god has almost

vanished among the top scientists.

The Material vs the Spiritual continued

• So science and religion are clearly not compatible.

• The more one learns about the real world, the less one can believe in a god.

• Reliable information usually comes from experts, and those who know about the universe, know there aren’t any gods.

Questions about philosophy itself





Where we are now


Questions about philosophy itself: Logic and reasoning

Logic and reasoning

Two types: 1.Deductive 2.Inductive

1. Deductive Reasoning

Classical philosophy: Plato said: • All men are mortal (a general premise) • Socrates is a man (a specific premise) • Therefore Socrates is mortal (the conclusion)

Premise 2

Premise 1

conclusion reasoning

Premises Or axioms Or propositions Or assumptions Or Postulates


Classical philosophy: Plato said: • All men are mortal (a general premise) • Socrates is a man (a specific premise) • Therefore Socrates is mortal (the conclusion)

Premise 2

Premise 1


This case is valid. What can go wrong?

Premise 2

Premise 1



Classical philosophy: • All dogs have 4 legs • Socrates is a dog • Therefore Socrates has 4 legs

Premise 2

Premise 1


Deductive logic is used to justify religions


How does deductive logic relate to the real world?

It is only as strong as the assumptions.

Premise 2

Premise 1


1. Deductive Reasoning If there are no aardvarks in the premises,

There can be no aardvarks on the conclusions.

Premise 2

Premise 1


1. Deductive Reasoning Likewise, if there are no gods in the assumptions,

there can be no gods in the conclusions.

Premise 2

Premise 1


No gods have ever been observed in the real world.

And they cannot just pop out of the reasoning.

This does away with the classical philosophers’ arguments for the existence of god: • Ontological Argument • First Cause • Argument from design

Deductive logic provides many tools for science

• Number theory • Algebra • Geometry • Set theory • Groups theory • Statistics

Deduction always starts from axioms. The question remains: are these axioms true in the real world? For general rules, this can never be “proved”… so science must turn to ...

2. Inductive logic

2. Inductive logic Classical examples:

All swans we have seen are white. Therefore all swans are white. Not true.

All ravens we have seen are black. Therefore all ravens are black. Probably true.

Induction in science

observations

Creative step

Make predictions (specific)

test

Form hypothesis (general)

Discard or

revise

fail

survives

pass

Make more predictions

test

Hypothetical deduction

Falsifiability

A good theory must be testable, ie make predictions which can fail. It must actually be tested. It must pass. Every time it survives a test, it gets stronger.

Karl Popper 1934: My proposal is based upon an asymmetry between verifiability and falsifiability; an asymmetry which results from the logical form of universal statements. For these are never derivable from singular statements, but can be contradicted by singular statements.

Bayesian Inference

H = hypothesis

E = evidence

Provides a theoretical basis for Popper’s falsifiability criterion.

Example from science Galileo dropping balls

from the Leaning Tower of Pisa

Try to form a hypothesis: 1. Deduction Everything I dropped has fallen to the earth (specific cases) Therefore, form the hypothesis: every object that is released, falls downward (a general rule). Not valid. But a god start.



2. Induction Form the hypothesis: every object that is released, falls downward (a general rule). Predict: Stones will fall Test: Confirmed. Predict: Apples will fall. Test: Confirmed. Predict: Cannon balls will fall. Test: Confirmed. GETS STRONGER EVERY TIME



2. Induction Until… Drop a helium balloon Falls upwards! FALSIFIED. Modify the hypothesis: All heavier-than-air objects fall downwards when released. PASSES ALL TESTS. Making it a stronger hypothesis. (or does it pass all tests?)

Example from the courtroom • INDUCTION • She went into the room • You went into the room • You came out carrying a

bloody knife • Therefore, beyond a

reasonable doubt, you are guilty

• CIRCUMSTANTIAL EVIDENCE.

• DEDUCTION • The witness saw you

stick a knife into the victim

• Therefore you are certainly guilty

• Valid – in a specific case only.

Summary on reasoning

• DEDUCTION

• Premises, reasoning, conclusion

• Appears to offer certainty

• Does not make predictions (general rules) about the real world

• Only as good as the premises.

• INDUCTION

• Hypothesis, predict, test

• Each time tested it gets stronger

• Can tell us about the real world

• Never offers certainty

• Offers confidence – more valuable.

Finis!

To continue the quest

• Australian Skeptics www,skeptics.com.au

• Humanist Society of NSW www.hsnsw.asn.au

• WEA lectures

• Sydney Uni Centre for Continuing Education

• Read New Scientist, Scientific American

• Lectures by scientists eg Sydney Science Forum

• [email protected]

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