From Quarks to the Cosmos - Christopher Newport University

advertisement

From Quarks to the Cosmos

Dr. Edward J. Brash

Christopher Newport University

Overview

What is the goal of science?

What methodologies do we use in science?

 How has our approach to science changed over the centuries?

How did we get to where we are today, in terms of how we view the universe?

Differing Points of View

St. Mark’s, Venice

Photo-realism vs. Impressionism [Whistler]

Differing Points of View

Main Path through the Garden at Giverny

Photo-realism vs. Impressionism [Monet]

Impression of Reality

 “I do what I can to convey what I feel before nature to pin down my sensations.” – Claude Monet (1912)

 “More than any other man, Whistler has helped purge art of the vice of subject and belief that the mission of the artist is to copy nature.” – George Moore

Perception of Reality

Theories

Physical Models

Data

Appearance of Reality

Reality

-Mirrors

-Distortions

-Emotions

-Beliefs

-Mythologies

What is physics?

 Φύσις

Ancient Greek – “physis” … meaning nature

 Webster:

Natural scenery

The external world in its entirety

The inherent character or basic constitution of a person or thing

The general analysis of nature, in order to understand how the universe behaves.

Natural vs. Supernatural

 “Natural things are things we can see, touch, understand and frequently manipulate. Nature, by definition, is the material world and its phenomena. Supernatural things encompass all things outside the natural world. Since supernatural things evidently have spiritual characteristics, it is not likely we can learn much about spiritual truth by studying and evaluating natural activity.”

– Pastor James Norman (Northside Baptist Church, Eden,

NC)

The Modern Scientific Method

Very little explicit information exists regarding early scientific methodologies

Edwin Smith papyrus (1600 BCE)

Ebers papyrus (1550 BCE)

 Empiricism – experience and evidence, rather than innate ideas and traditions

Theories must be tested against observations of the natural world (experiments).

 Aristotle, Francis Bacon, John Locke

Universal Truths

Aristotle (not a true empiricist) believed that one could infer universal truths using

INDUCTIVE reasoning.

Inductive reasoning is, by nature, probabalistic … given the premises, the conclusion is probable.

Example 1:

1. 90% of humans are right-handed.

 2. Joe is a human.

 3. Therefore, there is a 90% chance that Joe is right-handed.

 Example 2:

1. 100% of life forms that we know of depend on liquid water to exist.

 2. Therefore, if we discover a new life form, it will almost certainly depend on liquid water to exist.

 The branch of mathematics known as statistics allows us to make statements regarding the probability of any attribute of the entire population based on the details of the that attribute for a sample of the population.

Issues with Inductive

Reasoning

 Biases

 The Availability Heuristic:

Humans rely on information that is easily accessible

Example: 1948 Presidential Election – Truman vs. Dewey

 The Confirmation Bias:

Humans are more likely to look for explanations which confirm existing theories, rather than those which refute them.

 The Predictable World Bias:

Humans seek ORDER to explain their beliefs and experiences

Superstition: the inability to accept that coincidences are merely coincidences

Example: Gambling

– seeing patterns in outcomes

Deductive Reasoning

The process of reasoning from one or more general statements about what is known to reach a logically CERTAIN conclusion.

Example:

If John is sick, he will miss school.

 If John misses school, he will miss his classwork

Therefore, if John is sick, he will miss his classwork.

If the premises are true, then the conclusion is certain.

Aristotle used combinations of both inductive and deductive reasoning to attempt to understand the world in terms of UNIVERSAL TRUTHS.

The problem that still existed, however, was a lack of connection with

THEORIES.

Development of Scientific

Method

During the middle ages, science was advanced most notably in the Muslim world

 Scientists were often artisans, as well

 Expert instrument makers – allowed better experiments, with better data

Used experiment and calculations to distinguish between competing theories

Alhazen (Book of Optics – 1021)

 Developed the intromission theory of vision … we see by observing light rays emitted from/by objects, rather than from our eyes

Occam’s Razor

The Law of Succinctness

Among competing theories, the one with the fewest assumptions should be selected

 Example 1: Intromission Theory of Vision

 Alhazen states: “The extramission of [visual] rays is superfluous and useless.”

Example 2: Planetary Motion

 It is possible to describe the other planets in our solar system as revolving around the earth, but that explanation is unnecessarily complex compared to the contemporary consensus that all planets revolve around the sun.

Understanding Our

Universe in the 16

th

Century

Aristotle and Ptolemy

Aristotlean model - geocentric, with surrounding spherical shells

Claudius Ptolemy - patriarch of technical astronomy, codified in the Almagest (2nd C. A.D.)

 excentric circles with epicycles

 In Arabic, يطسجملا باتكلا ,al-kitabu-lmijisti, i.e. "The Great Book"

In Greek, Η Μεγάλη Σύνταξις,

"The Great Treatise"

Central Problems in 16th C.

Astronomy

The tables, which were used to predict eclipses, conjunctions, etc. were not sufficiently accurate.

Portugese and Spanish expeditions to the Far East and

America sailed out of sight of land for weeks on end astronomical navigation was crucial.

The calendar - equinoxes (on the 21st at the Council of

Nicea - 325 A.D.) had slipped to the 11th. Easter is determined in reference to the equinox, and most other holidays are referenced w.r.t. Easter.

Nicolaus Copernicus (1473 -

1543)

 Undergraduate work at U. of

Cracow (mathematics and optics)

 Followed by a decade in Italy

(canon law, then medicine)

 Returned to Poland, spent the rest of his life there, as a lawyer, physician, and church administrator (uncle)

 All of his observations were made with the naked eye!

Publish or Perish?

 Copernicus was reluctant to publish, not because of fear of the church, but because he did not feel that it was “ready”.

 Over 30 years of revisions (noted in original manuscript located in Prague mid. 19th C.)

Because it was published (widely) so late in his life, he never knew the stir that it had caused!

De Revolutionibus:

Foreward and Introduction

The foreward was written by Andrew Osiander much of the myth of Copernicus ’ fear of church reprisal comes from this!

 “For it is the job of the astronomer to use painstaking and skilled observation in gathering together the history of the celestial movements, and then - since he cannot by any line of reasoning reach the true causes of these movements - to think up or construct whatever causes or hypotheses he pleases such that, by the assumption of these causes, those same movements can be calculated from the principles of geometry for the past and for the future too.

De Revolutionibus:

Foreward and Introduction

 In the preface and dedication to Pope Paul III, Copernicus refers to the oral tradition of the Pythagoreans:

 “They seem to me to have done that not, as some judge, out of a jealous unwillingness to communicate their doctrines but in order that things of very great beauty which have been investigated by the loving care of great men should not be scorned by those who find it a bother to expend any great energy on letters - except on the money-making variety - or who are provoked by the exhortations and examples of others to the liberal study of philosophy but on account of their natural stupidity hold the position among philosophers that drones hold among bees.”

De Revolutionibus:

Book I

 “And we perceive the five wandering stars sometimes even to retrograde and to come to stop between these two movements.”

 Ptolemaic System: Epicycles

 Copernicus: “Therefore, if some movement should belong to the Earth it will appear, in the parts of the universe which are outside, as the same movement but in the opposite direction, as though the things outside were passing over.”

 Copernicus: “For the fact that the wandering stars are seen to be sometimes nearer the

Earth and at other times farther away necessarily argues that the centre of the Earth is not the centre of their circles.”

De Revolutionibus:

Book I

 “For if the annual revolution were changed from being solar to being terrestrial, and immobility were granted to the sun … it will be seen that the stoppings, retrogressions, and progressions of the wandering stars are not their own, but are a movement of the Earth.”

De Revolutionibus:

Repercussions

The latter half of the 16th C. saw the development of the telescope (Belgian/Dutch origin; refined by

Galileo, inter alia)

 1572 - SUPERNOVA!!!! (to be followed by a second in our galaxy in 1604) - a challenge to the premise of the fixed stars being “perfect and unchanging”

 Credited to Danish astronomer Tycho Brahe (1546-1601)

Lost part of his nose in a duel

Kidnapped by his aunt/uncle

Built a great observatory on Hven

Studied at Wittenberg

Brilliant experimentalist!

Invented “double blind” studies …

De Revolutionibus:

Repercussions

Tycho went on to create a

“hybrid” model of the motions of the planets - it was geocentric, but the other planets revolved around the sun.

Equivalent mathematically to Copernican model

(coordinate transformation)

Not accepted by either community

De Revolutionibus:

Repercussions

In 1576, a new edition of the famous Leonard Digges work, Prognostication euerlasting was being prepared, and Thomas Digges seized the opportunity to add a supplement to his father’s work:

 An English translation of Book I of De revolutionibus , and a diagram of the heliocentric system; it is entitled:

 A Perfit Description of the Caelestiall Orbes (according to the most aunciente doctrine of the

Pythagoreans, latelye reuiued by Copernicus and by Geometricall Demonstrations approued

 This is the first publication of the Copernican model in English!

 The translation is done phrase by phrase in Elizabethan style, rather than word by word.

 Several interpretations by Digges are worked into it: varying distance of the stars, as opposed to being fixed to one finite outer wall.

 Digges was the first modern astronomer of note to portray an infinite, heliocentric universe.

 Added a paragraph of his own, giving his opinion on the position of the earth, and in particular commenting on the “reasons philosophicall alleged for the earthes stabilitye”.

De Revolutionibus: xkcd.com

Repercussions

 Johannes Kepler (1561-1630) - German astronomer

 First important work on the relative distances of the planets from the sun - noticed by Tycho Brahe, who hired him as a “post-doc”, and set him about figuring out the problems with the orbit of Mars

 Published De Stella Nova in 1606, in which he discusses the 1604 Supernova

(Kepler’s Star)

 In 1609, he publishes a treatise in which he postulates that the orbits are

ELLIPSES, and that the orbit of the planet “sweeps out equal areas in equal times”

… these are Kepler’s Laws, and in addition to solving the Mars problem, they introduce DYNAMICS into the motion of the heavens.

 In 1615, Kepler’s mother was accused of witchcraft - he defended her at trial and won in 1620.

 Kepler was a devout Protestant, and refused to convert to Catholicism during the

Counter Reformation - this cost him his position on several occasions.

De Revolutionibus:

Repercussions

Tycho’s dying wish in 1601 was to have a new and accurate set of astronomical tables published for King Rudolf II, who had appointed him as Court Astronomer and Mathematician in Prague.

This task was entrusted to Kepler, who finally completed the tables in

1624, due in large part to issues surrounding access to Tycho’s jealously guarded data. After a long series of legal battles with Tycho’s heirs, the tables were finally published in 1627.

The accuracy of the tables was stunning and unprecedented - the predictions typically had a margin of error of 10 seconds or arc (10 arcsec = 0.028 degrees, compared with about 5 degree accuracy in previous tables).

Wait a minute …

Peter Usher, Penn State University – A

New Reading of Shakespeare’s Hamlet

Usher posits that Hamlet is an allegory for the contest between the cosmological models of contemporaries

Thomas Digges (1546 –1595) of England and Tycho

Brahe (1546-1601) of Denmark.

Shakespeare, Hamlet , & Stars…

Physics & English faculty members from

Southwest Texas State University believe the bright star described in Act I, scene i of Hamlet was the supernova of 1572, which

Shakespeare surely saw as a boy as it burned for 16 months before fading from sight.

Olson, Doescher, & Olson published their research in the November 1998 issue of Sky and Telescope magazine.

Peter Usher, Penn State University – A

New Reading of Shakespeare’s Hamlet

Hamlet, the hero, represents the Diggesian model, which expands Copernicus ’s heliocentric model to an infinite universe - the English ambassador arriving at the end with Fortinbras shows the synchronicity of the

Copernican and Diggesian heliocentric models

Rosencrantz & Guildenstern represent Tycho Brahe ’s hybrid model which attempts to conflate the heliocentric

& geocentric models – they are killed in England…You connect the dots!

Peter Usher, Penn State University – A

New Reading of Shakespeare’s Hamlet

Usher’s key points:

King Claudius is named for Claudius Ptolemy, who had a geocentric model – killing him represents killing his model

Fortinbras arriving in triumph from Poland at the end represents Copernicus & his heliocentric model winning in the end

Scenes/Lines Most Relevant to

Heliocentric Analysis

(Claudius’s speech from Act II, scene ii)

For let the world take note,

You are the most immediate to our throne ;

And with no less nobility of love

Than that which dearest father bears his son ,

Do I impart toward you. For your intent

In going back to school in Wittenberg,

It is most retrograde to our desire:

And we beseech you, bend you to remain

Here, in the cheer and comfort of our eye,

Our chiefest courtier, cousin, and our son .

Scenes/Lines Most Relevant to

Heliocentric Analysis

Act II, scene ii

HAMLET O God, I could be bounded in a nut shell and count myself a king of infinite space , were it not that I have bad dreams.

* * *

HAMLET I'll have grounds

More relative than this: the play's the thing

Wherein I'll catch the conscience of the king.

Scenes/Lines Most Relevant to

Heliocentric Analysis

Act II, scene ii

LORD POLONIUS:

Reads

To the celestial and my soul ’s idol, the most beautified Ophelia, ‘– That’s an ill phrase, a vile phrase: but you shall hear. Thus:

Reads

‘In her excellent white bosom, these, & c.’

QUEEN GERTRUDE:

Came this from Hamlet to her?

LORD POLONIUS:

Good madam, stay awhile; I will be faithful.

Reads

Doubt that the stars are fire; Doubt that the sun doth move ; Doubt truth to be a liar; But never doubt I love.

Online Shakespeare Concordance

(University of Sidney, Australia)

Frequency of key words in text of Hamlet:

Heaven(s)/heavenly - 55

Night(s)/to-night – 50

Day(s)/to-day – 31

Nature(s)/nature’s/natured – 31

Earth(ly) – 25

Son(s) - 21

Frequency of key words in text of Hamlet

(cont.):

England – 20

Still – 19

Stand(ing) – 16

Fire/fiery – 15

Star(s) – 10

Frequency of key words in text of Hamlet

(cont.):

Move(s)/moved/moving – 9

Month(s) – 8

Sun - 8

Tables/table - 8

Year/years – 8

Stop(s)/stopping – 7

Moon(s) - 6

Frequency of key words in text of Hamlet

(cont.):

Natural/unnatural – 5/4

Opposition/opposed/opposing - 5

Eternal/eternity/eterne – 4

Infinite - 4

Motion - 4

Wittenberg/university – 3/1

Dig/dug - 3

Order – 3

What is the conclusion?

The nature of nature, and the physics of our universe, was THE topic of the day in the 16 th and 17 th centuries

There was an unbreakable connection between science, art, literature, philosophy (both natural and supernatural!)

I would it were the same today, in many senses! 

Overview

What is the goal of science?

What methodologies do we use in science?

 How has our approach to science changed over the centuries?

How did we get to where we are today, in terms of how we view the universe?

References

The Galileo Project http://galileo.rice.edu/

Kitty Ferguson, Tycho & Kepler

 Dava Sobel, Galileo’s Daughter

 A. Rupert Hall, From Galileo to Newton

 Peter Usher, Hamlet and the Infinite Universe

Peter Usher, Harriot, Digges, and the Ghost in Hamlet

Download