TaK – Natural Sciences But Bob … in a quantum world - how can we be sure? Oh Alice… you’re...

TaK – Natural Sciences

But Bob … in a quantum world - how can we be sure?

Oh Alice… you’re the

one for me!

TaK – Natural Sciences

What are the Natural Sciences?

What differentiates them from other Areas of

Knowledge?

TaK – Natural Sciences

What methodologies are used in the natural sciences?

TaK – Natural Sciences

The Black BoxA structure for which your

description constitutes the only available truth

In groups: What can we know about the internal structure of the box?

TaK – Natural Sciences

The Black BoxWhat we know can be different

from what actually is

TaK – Natural Sciences

All national education systems take the view that it is

important to study science.

Why?

Joseph Wright – An Experiment on a Bird in the Air Pump 1768

TaK – Natural Sciences

Eratosthenes

TaK – Natural Sciences

1473 - 1543Nicolaus Copernicus

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Ptolemy 90 – c.168 AD Copernicus

TaK – Natural Sciences

Galileo Galilei 1564-1642

“…perhaps more than any other single person, was Responsible for the birth of modern science”

Stephen Hawking

TaK – Natural Sciences

Key to the discoveries and developments of science have been:• Proper standards of measurement• Paper & printing• A common language

of scholarship• Developments

in instrumentation

TaK – Natural Sciences

With telescopes and microscopes, enquirers (scientists) have made rapid progress in putting questions to nature, and in formulating answers

TaK – Natural Sciences

“Science is built with facts just as a house is built with bricks,

but a collection of facts cannot be called science any

more than a pile of bricks can be called a house”

Henri Poincare

TaK – Natural Sciences

“We found that the theory did not fit the facts – and we were delighted, because this is how

science advances”O.R. Frisch

TaK – Natural Sciences

The facts are coming! The facts are coming!

TaK – Natural Sciences

Can we talk about ‘scientific truths*’

or should we talk about ‘scientific beliefs*’?

*a verified or indisputable fact, proposition, principle

*confidence in the truth or existence of something not immediately susceptible to rigorous proof

TaK – Natural Sciences

“The progress of science is strewn, like an ancient desert trail,

with the bleached skeletons of discarded theories which once seemed

to possess eternal life” Arthur Koestler

TaK – Natural Sciences

Can you think of examples of things that were believedto be true by 19th century

scientists, but which we now know to be false?

TaK – Natural Sciences

Who is a Scientist?

TaK – Natural Sciences

Who is a Scientist?

By temperament …some scientists are collectorssome are classifierssome are compulsive tidierssome are detectivessome are explorerssome are artistssome are poet-scientistssome are philosopher scientists… and more

TaK – Natural Sciences

Who is a Scientist?In the broadest sense, we all can be…

‘Science’ – from the Latin ‘scientia’, meaning Knowledge

‘Science’ – an enterprise that builds and organises knowledge in the form of testable explanations and

predictions about the natural world

TaK – Natural Sciences

“Science is a way of thinking more than it is a body of knowledge”

Carl Sagan

TaK – Natural Sciences

Searching for, and finding, ‘Patterns’:

All bodies fall to earthAll plants…All metals…All liquids…All ecosystems…All chromosomes…

TaK – Natural Sciences

The scientific method

Put in order: 1. Test with experiments2. Ask questions3. Think! Try again4. Draw conclusion5. Report results6. Background research7. Observation8. Construct hypothesis9. Analyze results

TaK – Natural Sciences

Observation Ask question Background research

Construct hypothesisTest with experimentAnalyze results

Draw conclusion

Hypothesis is True

Hypothesis is False or partially True

Report results

Think! Try again

TaK – Natural Sciences

….. from Results you may be able to develop a Law* which can then lead to a Theory*.

*A scientific Law is a distillation of the results of repeated observation. It does not offer an explanation of phenomena.

*A Theory explains a wide range of phenomena on the basis of a small number of key ideas. A model of reality.

TaK – Natural Sciences

The scientific method

Problems with Observation:• Relevance• Selectivity• Expectations• Expert seeing• Observer effect

TaK – Natural Sciences

The scientific method

Problems with testing Hypotheses:

• Confirmation bias• Background assumptions

TaK – Natural Sciences

The scientific method

Problems with testing Hypotheses:

What makes a hypothesis a good hypothesis?

TaK – Natural Sciences

“We’ve discovered a massive dust and gas cloud which is either the beginning of a new star, or just an awful lot of dust and gas.”

TaK – Natural Sciences

TaK – Natural Sciences

Problems with Induction:• Reasoning from the observed,

to the unobserved• How many observations

should be made before we jump to a generalisation?

TaK – Natural Sciences

According to Karl Popper, science should be based

on the method of conjecture and

refutations, and scientists should try to falsify

hypotheses rather than verify them

TaK – Natural Sciences

Truth tests:• Correspondence

Statements scientists make must correspond to what can be observed in the world

• CoherenceObservations and measurements should be consistent with each other and the explanations they give about phenomena should also be consistent with each other

• PragmaticWe accept certain assumptions without empirical proof – because they happen to work. For example, we assume that nature is regular and understandable; we assume that the laws of physics are applicable all across the physical universe.

TaK – Natural Sciences

or

New explanations replace old through falsifying?

New explanationscoexist with old?

Which? Why?

Scientific Progress….

TaK – Natural Sciences

Knowledge

Time

Smoo

th p

rogr

ess

TaK – Natural Sciences

Knowledge

Time Time

Knowledge

Time

Knowledge

Time

Other models of progress:

Knowledge

TaK – Natural Sciences

Paradigm* ShiftThomas Kuhn:

A scientific revolution happens when scientists become unhappy with the prevailing paradigm. If their ideas triumph, the new paradigm will replace the old….

* Thought pattern shared by a community

TaK – Natural Sciences

Time

Normal Science

Revolution

Normal Science

Revolution

Knowledge

Natural Sciences

PerceptionHow far do

expectations influence

observations?

LanguageWhat role do

metaphors play in science?

EthicsAre scientists

morally responsible for how their

discoveries are used?

ArtsWhat role does imagination play in the sciences?

HistoryShould scientists know about the history of their

subjects?

Human SciencesHow do the

human sciences differ from the

natural sciences?

EmotionWhat does

biology tell us about emotion?

ReligionHow similar is faith in science to religious

faith?

TaK – Natural Sciences

TaK – Natural Sciences

ToK Prescribed Titles 2010

“What separates science from all other human activities is its belief in the provisional nature of all conclusions” (Michael Shermer, www.edge.org).

Critically evaluate this way of distinguishing the sciences from other areas of knowledge.

• Keywords?• Knowledge Issues?

TaK – Natural Sciences

Some Key Points:• The success of the natural sciences has led some people to see

them as the most important form of knowledge• The traditional picture of the scientific method has science

consisting of five key steps: observation, hypothesis, experiment, law, theory

• Since scientific laws are based on a limited number of observations, we can never be sure they are true

• According to Karl Popper, science should be based on the method of conjecture and refutations, and scientists should try to falsify hypotheses rather than verify them

• (However, a hypothesis can no more be conclusively falsified than it can be conclusively verified)

• Although scientific beliefs change over time, it could be argued that each new theory is closer to the truth than the previous one

TaK – Natural Sciences

KnowledgeCreator(s)

Works ofKnowledge

(math proof,research paper,

novel etc)

KnowledgeCommunity(peers, critics,general public)

Within context of the natural worldNatural world influences what is studied, and how it is studied

and the creation of knowledge has an effect on the natural world

Within social contextSocieties influence how knowledge is created and judged

and knowledge affects societies and cultures

TaK – Natural Sciences

“You are completely free to carry out whatever research you want, so long as you come to these conclusions”