AS Science in Society 1.11 Teacher Notes

AS Science In Society 1.11 Teacher Notes

Page 1 ©The Nuffield Foundation, 2008

Copies may be made for UK in schools and colleges

AS Science In Society 1.11 Teacher Notes

How Science Works
Developing and testing scientific explanations and Relations between science and society
The activity is about the status of scientific knowledge relative to that of authority knowledge. An important point is that while there are individual scientists who see their knowledge as absolute, science is continuously exposed to new data that can show its ideas to be incorrect. Thus science can only ever provide provisional knowledge and not certain knowledge, and can only be judged by its continuing survival in the face of a flow of new data. Science says nothing about absolute knowledge, but leaves that to other kinds of human activity. The primacy of observation in science has, in the past, resulted in conflict with other kinds of activity.

Introduction

This considers the difference between scientific and non-scientific ideas, in the context of the origins of life. The ideas include the hypothesis that life did not originate on Earth. As such it highlights the significance of any future discovery of life elsewhere, and hence the profound cultural importance of ‘SETI’ projects. It is, of course, an area of sensitivity, and the activity does not set out to do anything other than to explore the distinction between scientific ideas and ideas provided by written authority. Any preference of one over the other is a matter for the student, in the light of exploration and with the benefit of thoughtful discussion.

A key part of the distinction is that science does not offer certain truth, despite the apparent confidence of some individual scientists. The provisionality is a weakness that is a strength – science can be checked, and is ever-exposed to falsification, by observation.

Resources

Students need the means to find out more about ideas of primeval soup, panspermia, and creationism.

The activity

Students work in groups three to explore each of the three ideas – primeval soup, panspermia and creationism. They then combine their findings.

Points that might be raised in discussion

Ideas 1 and 2 are both scientific hypotheses, in that they can be checked, and potentially proved to be wrong, by observations. Idea 3 cannot be proved to be wrong by observations, and is not a scientific hypothesis.

Ideas 1 and 2 are provisional – further observations could, potentially, prove them to be wrong. Such scientific ideas, however, are sometimes agreed by debate to be the best possible interpretation of observations, and then they might be called established theories. Idea 1 is probably the preferred theory amongst many scientists, but it is not established to the extent that theories of, say, the existence of atoms are. Idea 3 usually claims absolute truth – it is a matter of ‘faith’ that is either fully accepted or not accepted at all.

Many scientists will debate with passion about their preferred ideas, but if science works as it should (and it sometimes take time to do so) only those idea that are not falsified by observations will, ultimately, survive. Thus science is always exposed, by scientists, to new observations. Holders of faith,

in most cases, do not suppose that their fundamental beliefs can be shown to be false. Some religious organisations have been particularly intolerant of challenges.

Science yields predictive powers – the ability to forecast the behaviours of materials, for example. As such it is certainly very useful. It does not claim to provide absolute truth, but merely the best possible interpretation of observations. These interpretations often have profound cultural as well as practical significance (as in the case of the Copernican revolution, for example).

Science deals with the observable, and faith does not. They are not fundamentally in opposition, although scientific interpretations have sometimes required religious authorities to change their views.

October 2008

Page 1 ©The Nuffield Foundation, 2008

Copies may be made for UK in schools and colleges

AS Science In Society 1.11 Student sheets

Introduction

How did life begin on Earth? It’s a big question.

There are some ideas that can be tested by observation. These are scientific hypotheses.

An idea that can’t be tested by observation is not necessarily wrong. There is no way of checking directly to see if it is wrong or if it is right. The only way to judge it is by its ‘authority’ – the authority of the written word or of established human organisations.

Here are three ideas:

IDEA 1: Primeval soup – some complexities are better than others

Complex carbon-based chemicals existed on the young Earth, billions of years ago. Influences such as sunlight and lightning produced some increasingly complicated chemicals. There was no shortage of time, and many kinds of complex molecules formed, though most of them did not last very long. Some of the chemicals – very few to start with - were able to make copies of themselves, so that when the original molecules were destroyed by their environment the copies still existed, and these could make more copies. Complexity increased – groups of molecules that could work together were particularly advantaged. Some molecules could capture energy from sunlight, for example, while others could form sacks to hold the collaborating molecules together. Complex collections of molecules became cells, like the cells of bacteria, algae and humans that we can see today.

IDEA 2: Panspermia – we are all aliens

This is a similar hypothesis to ‘primeval soup’, with the big difference that it makes the suggestion that the early stages of development of complexity did not take place on Earth. It suggests that the molecules or collections of molecules that provide the basis for life exist across the Universe. In suitable places, such as the Earth, these can develop into more complex forms over very long periods of time. Complexity that makes survival more likely is, well, more likely to survive. It’s a process of natural selection.

IDEA 3: Creationism – human life was created in its present form for a purpose that lies outside nature

The previous ideas do not provide a reason WHY complexity should increase and life should begin, but they provide suggestions of HOW it could have happened. Some people believe strongly that there must be a reason why – that life, especially human life, exists for a purpose. This purpose, they believe, lies outside observable nature, or is ‘supernatural’. They believe that the purpose was and is provided by a God or gods who care about the lives of individual people. Creationists go further, and where the writing (or text or scripture) specifies a particular timescale for the history of the Earth and of life that is at odds with timescales developed from observations, they dismiss the analysis of the observations.

The activity

In a group of three, each choose one of the ideas. Find out more about your allocated idea. Find out:

what its origins are
whether it makes predictions that can be checked by observations
whether those who accept the idea believe that it provides certain truth
whether it accepts or dismisses challenge to its suggestions or claims

Decide:

whether the idea is scientific a scientific hypothesis or a non-scientific idea
whether the idea claims to have ‘provisional’ or uncertain truth
whether the idea claims to have absolute or certain truth
if extraterrestrial life were found, what that might that tell us about the three ideas

Present your information and conclusions to the rest of the group.

You could repeat this by choosing three people from the class to make presentations to the whole class.

Discuss:

People with faith believe that human life has a supernatural purpose. Science does not address questions of purpose but only questions of processes. It does not provide certain or absolute truth but is always open to question. Does that mean that:

science – trying to understand the world through observation – is a waste of time?
that science and faith are incompatible opposites?

Copies may be made for UK in schools and colleges