*Between Understanding and Trust: the Public, Science and Technology*, Amsterdam: Harwood Academic Publishers.

4.3 Phenotypic changes that appeared without being selected

As well as these behavioural changes, many of the selected foxes had unusual white markings (Figures 13c and d). The first colour change that the Russian investigators noted in their foxes was a white â€˜starâ€™ on the forehead similar to that of other domesticated mammals (Author(s):

To account for its brightness and activity, the Sun must contain a power source. However, the nature of that power source was a great puzzle in the nineteenth and early twentieth centuries. Fossil records and ideas about evolution were beginning to provide firm evidence that the Earth must be at least hundreds of millions of years old, rather than thousands of years as was previously thought, and the Sun must be at least as old as the Earth. The only fuels known at the time were coal, wood, o

Coevolution also underpins the relationship between many tree squirrels and the trees that house them. The creation of food caches as a â€˜winter-larderâ€™ is mutually beneficial, partly because squirrels are sufficiently profligate in their habits to ensure that many stores are overlooked. Stealing by neighbours is so common that such over-provision may be essential â€“ it's not through forgetfulness or lack of skill; grey squirrels appear able to detect nuts buried as deep as 30 cm below th

You are about to meet some very large numbers, expressed in scientific notation, and some new units. The new units are those that are used to measure the amount of solar energy received by a part of the Earth's surface. Since plants are dependent on light for photosynthesis, the amount of plant material that ca

In Activity 1, below, you are asked to make notes from a TV sequence and then select some of the information from your notes and combine it

Insects are generally very small animals. Many kinds are hard work to collect and not very nutritious because a high proportion of their mass is a protective and indigestible outer layer, called cuticle. Insectivorous mammals need to eat large numbers of insects to fulfil their energy requirements.

Insect eaters have diverse ways of catching and dealing with their prey; teeth play a crucial role. Indeed, teeth are of such enormous significance to mammalian diets in general (and are so r

Sixty-five million years ago, animal and plant life were very different from nowadays, but there were rat-sized placental mammals living successfully on the ground. They were insect eaters, i.e. insectivores, feeding on the vast numbers of insects and other invertebrates living in soil, leaf litter and low-lying vegetation. Insectivore means â€˜insect eaterâ€™, and in this unit we will explore the world of insect-eating mammals, classified together on the basis of a reasonably close evolution

As we have said, the photons in the 3 K background have been practically free from interaction with anything since about 4Â Ã—Â 10^{5} years after the instant of the big bang. The present *angular distribution* of the microwave radiation â€“ the way in which it is spread across the sky â€“ is therefore almost the same as it was then. The spectrum we find today depends on the temperatures at that time â€“ for the intensity of the radiation in a particular region of the early Unive

5.2 The origin of the 3 K radiation

In speaking of the radiation as having a cosmic origin, what do we have in mind? Essentially this:

In the violent conditions of the early evolution of the Universe, a stage was reached where the matter consisted of a plasma of electrons, protons, neutrons, and some light nuclei such as helium. There were no atoms as such for the simple reason that atoms would have been too fragile to withstand the violence of the collisions that were taking place at the temperature that then existed. As

Having interpreted the redshift as indicating a recessional speed proportional to distance, one may extrapolate into the future to predict how the positions of the galaxies will evolve with time. One can also run the sequence backwards, so to speak, to discuss what their positions were in the past. Clearly, at former times the galaxies were closer to each other.

But not only that. Because of the proportional relationship between speed and distance (Equation 6), at a certain time in the

In this section, we bring together two important features of galaxies â€“ their redshifts and their distances.

This crucial development owes its origins to Edwin Hubble. His pioneering work in 1923 first led to the confirmation that certain of the fuzzy patches in the sky, loosely called â€˜nebulaeâ€™, were in fact galaxies like our own.

5.1.4 Getting agreement with the no-monopole law

Substituting Equation 7.23 into the no-monopole law gives immediate agreement because

The no-monopole law is analogous to Gauss's law in empty space, and it leads to a similar conclusion: the magnetic wave must be transverse. This has already been established using Farada

5.1.2 Getting agreement with Gauss's law

Substituting the assumed form of the electric field (Equation 7.20) into the empty-space version of Gauss's law (Equation 7.16) gives

The first two partial derivatives are equal to zero because *f* does not depend on *x* or *y*. So we obtain

3.6.5 Using the gradient of a semi-logarithmic graph to calculate doubling time or half-life

Knowing the equation allows you to perform several useful calculations without needing to make a graph, and we'll look at one such example in a moment.

First, let's return to the gradient of the exponential increase graph in Author(s):

1.3 Marking decimals on a scale

Figure 2 shows a picture of a ruler. The major units are marked in centimetres (1 to 11 cm), whilst the intervals between the centimetres have each been split into ten equal, smaller units. These minor units are therefore *tenths* of a centimetre, commonly known as â€˜millimetresâ€™. (There are 10 millimetres in 1 centimetre

Simple rules for dealing with orders of magnitude and decimal points in decimal numbers: values ten times bigger than the order of magnitude you are looking at go to the left, ten times smaller go to the right, and less than 1 to the right of the decimal point.

*Note:* in many European countries, a comma is used instead of a decimal point. For instance in France and Germany two and a half (in other words 2.5) can be written as 2,5. This is important to bear in mind, for example, if

Suppose you have less than one of any particular unit: how would you represent that using the decimal system?

Well, we've already seen that decimal numbers rely on a positional system, in which values get smaller by factors of ten as you read from left to right. If we continue doing this, then the number to the right of a single unit represents tenths of that unit. A **decimal point** is then used to mark the boundary between the whole units and tenths of that unit.

For instanc

1.1 Introducing the decimal system of numbers

Many different systems for writing numbers have been developed over the history of humankind.

The easiest way of counting small numbers is to use your fingers, and for this reason many numerical systems, such as the decimal system, are based around the number ten. But what happens when you run out of fingers to count on?

Numbering systems get round this problem by using a system of *scale* in which many small units are represented by a single larger unit, and many of these la

By the end of this unit you should be able to:

understand the decimal system of numbering (hundreds, tens, units);

explain the best way to write down decimal numbers and associated units of measurement in the healthcare workplace, in a manner that avoids confusion;

understand the concepts of discrete and continuous variables and the best types of graphs used to represent these data;

analyse, construct and extract information from grap