The Reasoning

How do we prove that the universe evolved?

The Scientific Process: METHOD

“Science” comes from the Latin word ‘scientia’, meaning knowledge


How we do science

What is Science?

Science is a process that enables us to gain knowledge about the World and the universe that we live in. We can then use this knowledge for practical purposes to improve our lives. Science gives us a means to describe the World and provide explanations of how and why it works like it does. We gain an understanding through what we see in observations and experiments. We can also explore the World of things we cannot see directly; things from the past such as dinosaurs and unobservable things such as atoms and the centre of the Earth.

Science is generally divided into two groups of activity:

  • • Natural sciences such as Astronomy. Physics, Chemistry, Biology and Geology. These study the natural World based on observations, by looking at it and testing it, and then develop theories based on what we have observed. The natural sciences rely on being able to repeat the experiments and get the same results. These subjects are easily identified as science.
  • • Social sciences such as Psychology, Sociology, Anthropology and Economics. These are the study of human behaviours and social interactions and are also based on observations and testing. Human behaviour is unpredictable and varies between people and even for the same person on a different day. So getting repeatable observations is not as easy as with the natural sciences. In addition, doing experiments with humans has many ethical considerations and so experiments may have very small numbers of people involved, and in very limited circumstances, and this can limit the conclusions that can be reached. This means that some observations may be objective and scientific, and some may be subjective and not scientific; it is necessary to be clear which work is scientific and which is not. This can be hard for scientists as well as the public to understand and can lead to misleading conclusions, especially if all the results are not published.

Then there are the activities that are not science although defining these is trickier than it may at first seem. Things that may seem scientific but are not were called ‘pseudoscience’ by the Austrian-British philosopher Karl Popper (1902-1994); he said the}' are beliefs with no evidence and are therefore not justified and are not a science. Popper classified astrology, psychoanalysis and Marxism as pseudoscience. Popper characterised pseudoscience as general, vague theories that could explain all things and made no specific falsifiable predictions. In contrast, he characterised science as providing specific, novel, risky predictions and required scientists to be willing to reject a theory if the predictions were not observed. Determining what is a science and what is not is called the ‘demarcation problem’. This is not a simple problem and continues to be an active area of philosophical debate today.

So what makes a science different than a non-scientific subject? A science is a way to find out knowledge. This in itself isn’t helpful unless we define knowledge. A generally accepted definition by philosophers is that knowledge is something that is true that we believe in - knowledge is justified belief. Scientific knowledge is justified because it comes from evidence. To help us define what is not a science we can define what is not knowledge. Something is not knowledge if:

  • 1. We believe it but it isn’t true - then it is not a science. For example, I believe my friend is Italian when in fact they are Greek.
  • 2. It is true but we don’t believe it - then we don’t know it. For example, If I don’t believe the Earth is a sphere.
  • 3. It is true and we believe it but we can’t know that it’s true. Predicting something that happens randomly is not knowledge, for example, if I believe my friend will win the lottery and then they do, this is not knowledge because I could not have known that they were going to win on that day. This is a subtler way of identifying a pseudoscience.

So knowledge is something we believe and is true, and science is a way of gaining this knowledge by finding out about the World from evidence we have gained using observations. A simpler way of saying this is that science is evidence-based knowledge. From the evidence we gain we can reach conclusions which gives us knowledge of what is true rather than belief or opinion. What science gives us is a method to gain knowledge that is justified by the evidence.

The Basic Scientific Process

Scientists arrive at beliefs by a process of reasoning


  • 1. Gather evidence through observations and experiments
  • 2. Make conclusions based on the evidence
  • 3. Develop a theory to explain the evidence
  • 4. Make predictions based on the theory
  • 5. Gather more evidence to prove the predictions
  • 6. Re-evaluate the conclusions and theory

Methodology is at the heart of science. How science is done is important and the methods that we use today have been developed over centuries. The basic scientific process was developed during the Scientific Revolution in the 16th and 17th centuries through the work of Copernicus, Galileo, Kepler and Newton. These scientists naturally developed and used the scientific process but it was written down and pulled together into a methodology by the English philosopher Francis Bacon (1561 1626) in his book 1Novum Organum (translated as ‘New tool’) in 1620 and today it is still considered to be the core of the scientific process.

Bacon’s scientific method revolves around two key concepts:

  • 1. Observations: that are recorded without prejudice
  • 2. Induction: making conclusions from the observations

Why was this so radical? It seems normal to us today but at that time it was thought that science was about recovering the knowledge of the Ancients particularly from the teachings of Aristotle. The Aristotelian way of gaining knowledge was by using logic and intuition, evidence and experiment was not important. This way of studying continued for over 1,500 years (through the medieval dark ages). The mindset changed due to the successes of Copernicus,

Galileo, Newton and Kepler. It took time for the new process of science to be recognised as a powerful way of gaining knowledge and to become established.

Although we think that new scientific ideas should be accepted by the strength of the evidence, in reality, like anything new, it needs to be marketed in order to get other scientists to agree and to get funding. History has shown that the scientists themselves need supporters; cheer-leaders that support what they are doing and the way they are doing it. This is especially so when a new theory or method is being proposed because scientists have to be persuaded to reject the established way of thinking and this is not easy. The need for marketing and cheer-leaders is as true today as it was 400 years ago.

This was the role of Francis Bacon, he was a cheer-leader for a new way of doing science. Bacon was part of the court of Queen Elizabeth 1 and was Lord Chancellor for two years so he had the ear of the rich and powerful and was well placed to influence the accepted view of scientific reasoning. Surprisingly, Bacon was not a supporter of the scientific ideas that were being proposed by Copernicus and Galileo (he did not believe in the heliocentric universe) but he was looking for a different way of thinking than the Aristotelian approach. Unlike his contemporaries, he believed that the Ancients didn't know everything and that there were new things to know. What made Bacon a true visionary was that he also believed that new knowledge should be used for practical purposes. He is reputed to have said “knowledge is power”.

Although Bacon was part of the elite, his views on science were egalitarian. In his book he proposed that science should not be done by just a few people but by many people working together as scientists to understand the World. Today, this is how science is done. It is only through the research of numerous different types of people from around the World, working in teams, covering many different disciplines, and sharing what they learn, that we have the knowledge we have today being used to create the technological society we live in. Bacon argued for co-operation and methodology in science rather than individualism and intuition. It is these values that has made science an important and powerful tool and enabled huge changes in society.

The evidence-based methodology of science proposed by Bacon has been a powerful driver in gaining new knowledge and developing new practical applications that have changed society. This has led to some believing that this is the only way to do science. British philosopher Bertrand Russell (1872 1970) supported the belief that science is the only way to attain knowledge, a view that is called naturalism. Some take it to the next level of complete worship of the scientific process, called scientism. The opposing view believes that science is not the only way of understanding the World, that the arts, humanities and philosophy produce knowledge too. Whatever you believe, there is no doubt that the scientific process has influenced human society beyond what anyone could have imagined 400 years ago.

How Do We Collect Evidence?

Evidence is the foundation of scientific endeavour. Through the production and analysis of evidence, that is objective and repeatable, science becomes a powerful tool to understand the World. Evidence comes from observations of nature: looking at rocks, plants, animals, humans and stars. Evidence also comes from carrying out experiments which allows us to get evidence for the unobservable things such as radioactivity, electricity and forces. Evidence about the unobservable has to be particularly convincing for sceptics to believe it. To be convincing we have to have a clear method that is accepted by other scientists as a process that will lead to objective data. So how we collect evidence is important. Being impartial and accurate when collecting evidence is essential for good science.

How do we choose what evidence we collect? Firstly, we do what we can do at that time. This may sound obvious but it is important to recognise that we are limited by what technology is available, what ideas we have and what it is possible to do. We may be able to make predictions and think of experiments but if the right conditions, technology and ideas are not available then we cannot do the experiment so we have to wait until we can. An example of this are gravitational waves that were predicted by Albert Einstein in 1915 when he developed his general theory of relativity. It was 100 years later, in 2016, that technology had improved enough for the first gravitational waves to be detected. Sometimes we may never get the evidence we want so we have to explore alternative ways that may give us clues in a more indirect way. For example, we are unlikely to ever be able to get direct evidence that will tell us what the Big Bang was but we can develop theories that give us other clues that we may be able to test to give us indirect evidence.

Experiments are not simply gathering data but involve designing tests for our theories. Francis Bacon said that we need “to torture nature for her secrets”, by which he meant that we need to do experiments in order to see what the limits of nature are. We choose from experience what to vary in experiments and we also simplify the experiments to make them understandable and reproducible. We do this by using ideal systems such as in a vacuum or using a sphere to simplify the shape. Experiments are important for a variety of reasons:

  • • Experiments test theories in ways that wouldn’t happen otherwise, they ask ‘what if?’
  • • Experiments need to be repeatable so that others can check the results and confirm the theory.
  • • Experiments need to measure things to standard agreed definitions in order to limit the subjective affects of bias and perceptions of the observer on the results.

It is common in experiments to require using random samples to reduce any subjectivity that scientists may bring to the test. 'Randomised control trials’ (RCT) are used regularly in biomedical science. A control sample is one where the treatment is not performed. The outcome of the control group is then compared to the group that had the treatment to see if they had significantly better outcomes. An RCT is one where the allocation of people into the control group or the treatment group is chosen randomly and in some cases may not be known by the scientists performing the experiment (this is then called a blind experiment). Randomising the test helps to eliminate factors that are not being tested, for example, age, diet and exercise.

When there are two ideas to explain the same evidence Bacon proposed that an experiment be designed that results in a different outcome for the two ideas. This experiment will then show which idea is supported. This is called a ‘perjorative instance’. However in designing the experiment we already have preconceived ideas so it could be argued that this experiment is influenced by our prejudices, something we do not want for good science. Bacon argued that this experiment should only be designed after the initial investigation has been done so that the subjectivity is acceptable.

A more recent way of collecting evidence is by using a computer. We put into a computer the rules of physics, chemistry, biology and then try out different models and see which one fits the observations. We can model the evolution of the universe by programming the laws of physics into a computer and letting it calculate the way matter evolves to create stars and galaxies. By comparing the picture of galaxies that the computer produces, to what we observe when we look at galaxies, we can see which model fits the best.

Today, there is so much knowledge in science that one person cannot know it all. It takes many years to become an expert in one particular discipline so it is necessary that, for an individual, evidence also comes from what we learn from others: from books, publications, lectures, discussions and the internet. This is not new evidence (although it is new to the individual) but it can lead to new theories and conclusions. Whether we trust this as knowledge depends on the source and how reliable we think that source is. One way of ensuring that the source is giving us ‘justified knowledge’ is to check that published research is of a scientific standard. This is done by requiring research to be reviewed by other scientists in a process called ‘peer review’. The purpose of peer review is to check that:

  • • the work has used scientific methods,
  • • the evidence gained is without prejudice,
  • • the conclusions reached are justified by the evidence.

Peer review is considered an essential part of the scientific process today.

More recently there are developments that question whether we need evidence to make an idea scientific. Traditionally, it has been assumed that science is working towards understanding the reality of how the World works.

Now, it is being debated whether we can ever really know what reality is or whether we need to know reality if our non-reality theories are able to make very accurate predictions. Two theories that are driving this debate are quantum theory and string theory. Quantum theory tells us how the microscopic world of fundamental particles behaves. The theory fits the evidence very well, makes predictions to high degrees of accuracy and we use it to build complex products such as computers. Although the theory works well we cannot explain why it works. We do not know what is happening in reality but we accept it as a theory. String theory is a mathematical theory that aims to explain how the quantum world and the large-scale world fit together. There is no evidence for the theory but it is very elegant and it can be argued that if it is consistent within itself then maybe that should be sufficient to say that it is a good theory. The problem with this argument is that if we reject evidence as the basis of science then we risk rejecting the very method that has given science it’s power. I like to think that we can know what reality is and I am motivated by finding out how the real World works.

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