The concept of time: can it be fully realised and taught?

Abstract

This article discusses the threshold concept of ‘time’ in relation to student teaching and learning within the GEES subjects. Preconception and sensory perception of the world is thought to play a key role in how students develop their ideas of ‘time’ in relation to their experiences, be it from non-academic life, classroom based learning or fieldwork. Geological time or ‘deep time’ is a clear example of the problems that students have in conceptualising time in contexts that do not relate to everyday situations. Combining complex terminology with the introduction of new concepts can further hinder the student’s proper understanding, for example, the concepts of radiometric-dating, absolute and relative time can create a mire of confusion. One possible solution is to revisit the expert’s own past learning experiences of such concepts as a means to bridging the barriers of knowledge transfer from teacher to student - the so called ‘aha!’ moments. Such insights could lead to the development of innovative teaching materials that overcome the problems. Applying properly supported analogies, either in fieldwork or the classroom, can result in effective teaching approaches. However, we should always remain vigilant that student preconceived ideas and perceptions may inhibit proper understanding and learning progression.

Introduction

What is ‘time’? Can it really be fully realised and taught? These may seem like simple or unusual questions at first glance, but are they? The teaching and learning of difficult concepts or ‘threshold concepts’ (Bradbeer, 2005; Cousin, 2006) is already of concern to academia. A threshold concept has two main characteristics which should be borne in mind:

“It is transformative, leading to a significant shift in perception or a new world view; and it is irreversible, unlikely to be forgotten and more or less impossible to unlearn.”

(Bradbeer, 2005, p. 3)

‘Time’ is an interesting ‘threshold concept’ that was open to debate at the GEES summer conference, What on Earth…? Student learning in geography, earth and environmental sciences in June 2006. This article looks at the profound concept of ‘time’ with reference to teaching in the GEES subjects, highlighting and expanding upon the thoughts given by the authors during their discussions at this event.

Where do we start in understanding ‘time’? Our perceptions of time

“Our cognitive brain is especially endowed with neuronal mechanisms that can model within their biological structures all conceivable worlds, as well as the world we directly perceive or know to exist. External expressions of an unbounded diversity of brain-created models constitute the arts and sciences and all the artefacts and enterprises of human society.”

(Trehub, 1991)

What is thought provoking about this statement from Trehub is how the subjective and objective relate to our understanding of the world; when does something imagined relate directly to reality? It is important to note here that an understanding of what we perceive time to be and what it actually is are not always synonymous. On a philosophical note, Plato considered our world as we know it, to be an imperfect copy of a conceptual world. This in essence could mean that what ‘actual reality’ is, what our preconceptions of reality are, and how we perceive our realities to be, are all entirely different things. This is a paradox in itself, of which later philosophers such as René Descartes were also aware. Descartes (1641) considered sensory perceptions inferior; our sensory perceptions can mislead us in the pursuit of ‘true’ knowledge. So, how do we start to develop our own concepts of time from that we perceive in an environmental context?

How do students cope with different views of time?

As members of GEES, it seemed appropriate to start our discussions with the subject of ‘geological time’ or ‘deep time’, as it is sometimes referred to (Trend, 2000; Zen, 2001). Yet we immediately hit upon a problem; geological time is vast, containing impossibly long periods of time, that students may have particular difficulties comprehending or imagining (Libarkin et al., 2006; Libarkin et al., 2005; Schoon, 1992; Trend, 2000).

Effective teaching of geological time could involve visual representation of growth via observations of appropriate landscapes; although such dramatic environmental changes may be difficult to teach. How do students link their own understanding of normal day-to-day time to such vast geological time frames, when ‘… most of time in the geological sense is missing’?

Perhaps we should start by teaching students that there are indeed ongoing scientific debates around the concepts of time. Not all it would seem is ‘cut and dried’, so to speak. It was agreed that analogies would play an important part in overcoming difficult concepts. Incorporating tools like time-lapse (displaying images of changing landscapes rapidly using video) or perhaps a clock could be used as powerful metaphors to the ‘passage of time’. It was very much open to debate whether we should ensure that ‘time’ is a specific focus in the classroom (explicit) rather than it being subliminally learnt. Clearly we need to understand which aspects need to be taught in an explicit fashion and which can be omitted without detriment to the students’ overall concept of time; a topic that requires further discussion elsewhere. It was suggested that such facilities like the ‘immersive vision theatre’ project; currently being developed at University of Plymouth by the Experiential Learning Centre for Excellence in Teaching and Learning (CETL) would be a great place to demonstrate ‘time’. This facility would allow creation of immersive visual and audio experiences that may not be possible elsewhere, even in the field. All or some of these techniques could indeed be incorporated into the teaching of ‘time’ within the context of our own subject disciplines.

Absolute and relative time

“… experiments show that synchronous events can appear to an observer to occur at different times. Neural processing time delays are offered as an explanation of these temporal illusions, but equating perceived time with processing time leads to some thorny philosophical problems.”

(Johnston and Nishida 2001, p. R427)

To add to the confusion, the students have to consider the terms ‘absolute time’ and ‘relative time’. In geological terms, absolute time is determined by such means as radiometric dating - a scientifically proven method of dating objects by the radioactive decay of certain elements contained within their lattice, the rate of decay being constant over time. Interestingly, Pather (2005) found that students’ beliefs of the nature of radioactive decay differed from the scientifically accepted beliefs in their discipline. So it would appear that not only do students need to grasp deep time, but also the concepts of radioactive decay.

The term ‘relative time’ is used to describe the logical chronological positioning of these rocks in relation to each other over geological history, bringing with it the concept of uniformitarianism in the geological sense - the same processes that have shaped the past also shape the present. Research has shown that people’s

“… grasp of relative time is more secure than their grasp of absolute time, and instruments which address absolute time generate less conclusive evidence than do those requiring simple sequencing.”

(Trend, 2000, p. 539)

Absolute and relative times are all too easy for the experts to talk about, as they have already overcome such threshold concepts. For the student there are numerous questions they may wish to ask to enable them to understand the bigger picture. For example, how do scientists actually determine the age of the earth? Why is radioactive decay used in determining the age of rocks? Is radioactive dating really that accurate?

Deep time is all about long time frames, but what happens when changes are rapid?

“Some processes are over too quickly, others take too long for us to be able to perceive them. There is a window of time within which events must occur in order for the relations between them to be perceptible. But even so, this does not mean that there is a standard ‘unit of perception’ of time which is itself somehow represented in each perception. This is because perception can only ever discern temporal structure as the structure of a particular process perceived.”

(Hoerl, 1998, p. 160)

Interestingly, Sue Heard and Malcolm Holes’ (2006) presentation at the GEES conference described volcanic activity as big change in a short time, in direct contrast to other much slower geological activities. Geology is not all to do with large time frames.

The ‘aha!’ moments

“How did I get the concept of 4 billion years?”

Learning how the scientists came to understand these concepts is perhaps the first step. How and when our own concepts and perceptions of time changed as we grew from child to adult is one such approach to overcoming ‘time’ as a threshold concept. The point in our lives at which we said to ourselves: ‘aha! I know what it all means now’. Perhaps then it is possible to transfer this knowledge to others.

But have we actually ever reached a point of truly understanding what time is?

“… perceptual processes guide the construction of abstract concepts even when this direct link may not be so obvious. By adopting a perceptual perspective, we certainly do not mean to deny the use of abstract rules. On the contrary, our position is that abstract conceptual knowledge is indeed central to human cognition, but that it depends on perceptual representations and processes, both in its development and in its active use.”

(Goldstone and Barsalou, 1998, p. 232)

Measurements to promote the understanding of ‘time’

“Units are at the heart of science and thus of field and lab experiments, from river discharge to slope failure.”

(Whalley, 2006)

When we teach the concept of time, we tend to focus down on ‘sub-concepts’, pulling out things that normally get lost - essentially filling in the gaps. This idea of ‘filling in the gaps’ was highlighted in Julie Libarkin’s (2006) presentation, where she described how student opinions could somewhat differ from the reality; it was found that they combined actual knowledge with life experiences, which they remoulded to fit how they thought geological process happened.

Measurements, however, hold these concepts together and allow for a greater development of the imagination. Although ‘measurement’ may be an aid to our understanding of time, it should be borne in mind that there are times that our own perceptions or judgment can be clouded by external factors, particularity where approximations are concerned:

“People at an outdoor cafe were approached and asked to judge the distance to a soda can placed on the table within their reach. In one condition, the can had been given to the participants - it belonged to them - whereas in the other condition, the can belonged to the experimenter. Participants perceived the can to be closer when it belonged to the experimenter - and had invaded their personal space - than when it was their own soda.

(Proffitt, 2006: 134)

As demonstrated by Proffitt’s research, external influences can have a marked effect on our perceptions, and perhaps sometimes at the expense of the intended learning outcome for any given experience. Which begs the question:Are you comfortable in your space? This thought-provoking idea was answered in a piece of research examining students in a fieldwork environment: where it was found that students reacted differently depending on the format of the experience (Orion et al., 1997). It was also suggested

“… that the extent to which the outdoor event is integrated with the indoor learning strongly influenced the perception of the learning environment during the outdoor experience”

(Orion et al., 1997, p. 168).

Indeed, there are many different learning environments that can be utilised to aid in knowledge transfer, but can learning be better facilitated when in the field? The authors’ consensus was that the field is in fact a good place to learn, providing a plethora of opportunities in which to demonstrate the passage of time; real tangible experiences do help to bring together subjective concepts. Research carried out by Dodick and Orion (2002) is certainly in agreement with this view, as they found that:

“Fieldwork both improved the subjects’ ability in understanding the 3-D factors influencing temporal organization, as well as providing them with experience in learning about the types of evidence that are critical in reconstructing a transformational sequence.”

(Dodick and Orion, 2002, p. 708)

At the GEES conference, Brian Whalley (2006) described getting students to pace out ‘length’ to understand its unit - a clear demonstration of how visual and experiential approaches could be used effectively to introduce the concepts of measurement. The measurement of distance over time could be the next simple step to bring all these theories together. It was agreed that a repetition of such measurements can aid student understanding of more complex concepts as they progress in their studies.

Pat James (2006) also eloquently demonstrated the geological history of the earth by means of several rolls of toilet paper stretched among the delegates; each individual sheet representing a vast time frame. He finally concluded that the fibrous dust produced from a broken sheet represented the timeframe for which humanity has existed on the earth. A very simple, highly graphical and memorable example of using every-day items to teach complex concepts — certainly this is an image of a threshold concept that could not easily be forgotten.

Students from Queens University, Belfast, pacing out length

Is there enough time to teach time? The concluding remarks

Students’ concepts and perceptions of the threshold concept ‘time’ have been discussed, highlighting the difficulties in teaching discipline-related concepts, such as geological time (deep time). From our discussions, it would seem appropriate to recommend, or at least consider, the following when embarking on the ‘teaching of time’ in any chosen discipline:

• Establish an understanding of the student ideas of time and ensure that it relates correctly to the discipline.

• Consider your own ideas of time and how you obtained them (What are expert ideas of time?) and ascertain the best approach to applying these concepts.

• Consider whether to make teaching of time explicit or subliminal - ‘Making Time for Time’ in the curriculum.

• Include techniques that embody representations of measurement by means of: visualisation; role play; real-time events; simulation; using space to represent time - Experiential/Active Learning.

• Ensure repetition of key activities (particularly in regard to units of measurement) to ensure that students have fully grasped the initial concept before moving on to the next.

• Recognise the potential confusion of associations in the teaching of time, e.g. relative and absolute time — has the student grasped a proper understanding of these two concepts of time?

• Consider that people’s perceptions of an experience can be quite different from each others’, depending on the learning environment in which they find themselves.