## What is Knowledge?

Plato defined knowledge as “Justified true belief”. For a person to know something he/she has to believe it, has to be able to justify it and it has to be true. This is explained here.

The tree criteria needed for a person to know something are:

• Lack of justification: “I know that aliens exist” – there is no way that you can provide a justification for this claim. Therefore you can not know it.
• Lack of belief: “I know that the world is round but I don’t believe it.” – this is a contradictory statement. For you to know something you have to believe in it. But not every belief is knowledge!
• Lack of truth: I know that a circle has 3 corners. – You can not know things that are evidently not true.

Four possible ways to justify one’s belief are:

• Memory
• Authority
• Logics
• Empirical evidence

## What is the “4-Ears Model” of Communication?

According to Psychologist Friedmann Schulz von Thun, when a person talks to another person he/she is passing on four different messages. This communication model is called the “4 Ears Model” and is useful in understanding why people misunderstand each other.

Alice and Bob are both sitting in the car, Alice is driving. They are waiting at an intersection, the traffic light is red and then changes to green.

Bob: The traffic light is green.

Alice: Don’t be so impatient!

… and they start arguing. What went wrong? According to the psychologist Friedemann Schulz von Thun, a message that is passed from one person to another person carries four pieces of information: Continue reading »

## What are Formal Systems?

Introduced here: the MIU puzzle as an example of a formal system. A formal system is composed of axioms, to which rules of inference are applied to produce theorems to which the rules can be applied again. Confused? Try to MIU puzzle yourself – it’s fun!

The MU Puzzle is an example of a formal system. The objective of the MU Puzzle is to try to reach the string MU starting from MI, using only these four rules:

• Rule 1: xI ? xIU. If there is an I at the end of the string of letters, then you can add a U. For example if your string is MI then you can change it into MIU. You can only add a U if the last letter is an I.
• Rule 2: Mx ? Mxx. You can double any string that follows the M. So if your string is MIU then you can double the IU after the M. You will then get MIUIU. We have doubled the IU.

## What are the differences between Facts, Theories and Opinions?

The terms facts, theories and opinions are often confused. The objective of this edition is to clarify these terms. Facts are observations or measurements from an experiment, theories are the explanation of these facts, while opinions are assessments or evaluations.

The terms facts, theories and opinions are often confused. The objective of this edition is to clarify these terms. Facts are observations or measurements from an experiment, theories are the explanation of these facts, while opinions are assessments or evaluations. Opinions are often not scientifically verifiable or falsifyable.

## What is Determinism?

Determinism refers to the idea that the future is not up to chance, the future can be predicted. Determinists claim that if you had sufficient knowledge of the current situation, then you could in theory predict the behavior of a system into the future. Certain systems are indeed deterministic, many others are not.

In this edition we will have a look at the concept of determinism. In a deterministic system the initial conditions of the system determine the future behavior of the system. The behavior of both a falling apple and a rolling die depend on the initial conditions. Even the same laws of physics apply, namely classical mechanics. Both falling apple and the rolling dice are deterministic systems. But I am able to calculate the landing position of a falling apple, but I am not able to calculate the result of a die roll. Why? How are these two examples different? Why does the die seem to behave according to chance, but not a falling apple? A rolling die is chaotic and it is unpredictable, even though it is deterministic. Even if we know all the physical laws and the starting conditions of a system, it is still not possible to predict the future behavior of chaotic systems.

## What are Thought Experiments?

It is not always necessary to conduct real-life experiments to reach a valid scientific conclusion. Thought experiments may in some cases also suffice. In this edition I will illustrate you a thought experiment from physics: In a vacuum, all objects accelerate the same way and they both have the same velocity. Heavy objects will not fall faster. But how can we test this? We do not have a large vacuum chamber to test this. A thought experiment can be useful in this case.

In this edition of TOK-Talk I will explain you what a thought experiment is. Is it always necessary to conduct real-life experimets to reach a valid scientific conclusion? Listen to find out!

## Why are Simpler Explanations Usually Better?

The purpose of science is to make things simpler and not more complicated. Scientists strive to discover theories and explanations that simplify the view of our world and not complicate them. According to Wiliam of Ockham (c. 1288 – c. 1347), if there are competing explanations for a phenomenon, the simpler explanation is to be preferred. The simpler explanation is often the correct one. It can be summarized as “With all other things being equal the simpler solution is the better one.” Simpler explanations rely on fewer assumptions which can not be proven or disproven.

In this edition of TOK-Talk I would like to explore the difference between a good and a bad explanation. Why are simpler explanations usually the better ones? Listen to find out! Continue reading »

## What is the Scientific Method?

If we want to reach an objective description of our world, then we need to reduce these subjective influences. We need standardized procedures in gaining further knowledge of our world. The scientific method is such a standardized procedure in gaining further knowledge in the natural sciences.

One of the goals of science is to explain various phenomena of the natural world in an objective and unbiased manner. Different people perceive the world differently, due to different educational and cultural backgrounds. For some people a glass of water is half full, for others it is half empty, and still for others it is just a glass of water. Different people perceive and interpret reality differently. If we want to reach an objective description of our world, then we need to reduce these subjective influences. We need standardized procedures in gaining further knowledge of our world. The scientific method is such a standardized procedure in gaining further knowledge in the natural sciences.

## What is Falsification?

In this edition of TOK-TALK we will talk about Karl Poppers contributions to the philosophy of science. Sir Reimund Karl Popper is considered to be one of the most influential philosophers of the 20th century, and of course it is difficult, if not impossible to summarize his contributions in a few minutes (or a few lines). Where should you draw the line between the sciences and the pseudosciences? What characterizes scientific theories? In this edition we will have a look at the falsification principle which offers an answer to these questions.

In this edition of TOKTalk I will talk about Karl Poppers contributions to the philosophy of science. What makes a theory scientific and what is the principle of falsification? Listen to find out! Continue reading »

## What is the Observer Effect?

Every measurement changes the object that we want to measure. This is called the Observer Effect. When we stick a thermometer into a glass of water to measure its temperature, then the thermometer will change the temperature of the water as well. Similar effects can be observed when measuring voltage or current in electrical circuits. Also in the social sciences we have a similar problem: people will not behave naturally when they feel that they are observed.

In this edition of TOK-TALK we will explore if it is in principle possible to measure anything accurately. How does a measurement change the value of that what you want to measure? Listen to find out!

Here in front of me, I have a cup of hot water, and over here we have a thermometer. Let’s put the thermometer into the glass, we have to wait a bit for the temperature reading to adjust. For our listeners, it’s a digital thermometer with a metallic probe. You use similar thermometers to measure the inside temperature of a cake to check if it is finished baking. Continue reading »