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What is science?
- Professor Paul Davies: Science is a process. Science is about providing reliable descriptions of the world that enable us to make new discoveries.
- Key elements of scientific method: scepticism, critical enquiry, subjecting hypotheses to rigorous tests, the importance of advancing explanations that are open to falsification.
Science is not: a list of facts, body of knowledge, technology, a religion, a belief system.
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Intelligent design
- Claims that the nature of the universe (including evolution) is best explained as a directed process rather than resting on properties of matter and natural processes (eg. natural selection)
- An offshoot of 'creation science'
- Banned from being taught in schools
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Does it matter what science is?
- Many products are promoted with claims that 'scientists have shown' that the product works or is better.
- Some of these claims are misleading or false and involve little more than the assumption that a scientist is someone who wears a lab coat.
- Other claims are difficult for a non-specialist to see through.
things that are not science should not be promoted as science.
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What do scientists do?
- Scientists aim to explain particular aspects of the observable world.
- An accurate explanation enhances understanding of how our world works and allows us to produce different technology.
- Arguably, it is an adaptive behaviour, evolutionary speaking.
- Scientists aim to:
- Achieve some understanding of the real world
- Make accurate, objective observations of the real world
- Construct or test the theories that are the best current explanations of these observations (and therefore get closer to the truth- or to 'reality')
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Define fact, hypothesis, model, theory, law
- Fact: Something that is observed. Facts are not deduced from understanding or mechanisms.
- Hypothesis: A working assumption or provisional idea whose merit is to be evaluated. This is more than just a guess! Experiments and observations are designed to test hypotheses. According to some philosophers, scientists try to find evidence that will show that a hypothesis is false.
- Model: A framework based on observation and experimentation that needs to be tested further. Models may be mathematical in nature, or a flow chart or concept map.
- Theory: A model or conceptual framework that explains all existing observations and predicts new ones. A series of related hypotheses and experiments are likely to be involved in formulating a theory. It is NOT speculation, conjecture or “just a theory”. Importantly, theories must be testable.
- Law: A theory that is far-reaching and fundamental. It provides the ‘Big’ explanations, such as gravity, but can still be built on, expanded and improved.
- Theory as defined by Stephen Hawking:For a theory to be good, it must both:Accurately describe a large class of observations on the basis of a model that contains only few arbitrary elements.
- Make definite predictions about the results of future observations.
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What is the scientific method?
5 step model
- Scientific method provides an account of how scientific enquiry is carried out.
- Scientific enquiry is not just trial-and-error, it has the potential to diverge from known paths of thinking and provide counter intuitive answers.
Five-step Model: an iterative process, where each turn of the cycle leads to better and better explanations. Self correcting, always improving.
 - 1. Select an interesting phenomenon to study.
- 2. Propose a hypothesis
- 3. Experiment & observe
- 4. Construct theory/model to explain results
- 5. Make predictions from model & test
- 1. Compare to original observations
- 2. Refine hypothesis and go again!!
Theories that are repeatedly supported become "Laws"
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Prof. Peter Doherty's model of scientific method
- Hypothesis- experiment- publish- discuss
- Deficiency is that does not have a feedback loop, where the discussion leads to further hypotheses.
- Doherty highlights important aspects of the scientific process:
- 1. Science must be repeatable
- 2. The results are not legitimate until the work is published and discussed.
- Experiment is not finished until it is published.
- Highlights that publication, peer review and discussion is not an add-on, it is a fundamental part of scientific process.
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All good science should have the following elements
- Must include testable questions or hypothesis that have a yes-or-no answer
- It should be verifiable. Means you can find out the answer to the question; collect data and see for yourself. Also known as empiricism.
- The work has be objective, and not biased or with any preconceived ideas.
- The results must be repeatable; each time you do the same test under the same conditions, you get the same answer.
- It should provide logical explanations using all available knowledge and those explanations in turn must be testable.
- The results and arguments should be examined critically, using scepticism.
- Has to include a mechanism whereby the results can be disseminated, discussed and evaluated.
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Two views on the scientific process
- Karl Popper: philosopher argued that the correct way to implement science was the hypothesis-deduction method (that is, starting at step 2 in the scientific method cycle)
- He thought scientists should:
- 1. start with a hypothesis
- 2. Work out what to expect by deduction
- 3. Perform tests
- 4. Compare the results with the expected outcome.
- Thomas Kuhn: observed what scientists actually did rather than philosophise about how science should work.
- He found that most scientists started with some data and then make a hypothesis using inductive reasoning (start at step 3 in the scientific method cycle and then go back to step 2).
- Inductive reasoning: making observations and creating a hypothesis/theory based on that.
- In practice, a bit of both happends
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