In the Beginning, there was ... Philosophy.

The question of whether humans enjoy free will (or not) has occupied people for centuries. Science has not yet found a definitive answer but we are all familiar with the phenomenon. When we want something (a mental event), we get up to get it (a physical event). When something happens to us (a physical event), we react with, say, sadness or joy (a mental event). How is this possible? How can physical events influence mental states? And how can mental states lead to physical events? In this Episode I introduce to rival accounts: determinism (which claims that we are not free agents) versus libertarianism (which holds that our mind are free to choose between options). I discuss the pros and cons of each position and conclude that I am more convinced by the libertarian argument, i.e. the belief in the freedom of the will unless proven otherwise.

In previous Episodes, I have made many references to the laws of nature. Laws of nature are the regularities in the natural world, which exist independently of our knowledge of them. But in the textbooks of science you find many equations which encode the natural regularities. These equations are the laws of science. The laws of science are only approximately true because the employment of mathematics involves the use of abstractions and idealizations.The laws of science are subject to modifications, but the laws of nature just are. I limit myself to two philosophical attempts to explain what the natural laws tell us about the natural world: the regularity view and the structural view.

In this Episode, I discuss some systematic ways in which discoveries are made in science. This follows on from Episode 13 (A, B) which introduced thought and real experiments. In this Episode I look at methods - systematic ways - to go about scientific discoveries. There are three methods: two different forms of induction and deduction. Induction works either by inferring from some to all cases (from 'some ravens are black' to 'all ravens are black') or by the method of elimination. To illustrate the latter method I compare the work of a scientist who tries to solve problems, to the work of a detective who tries to solve a crime. The detective tries to eliminate potential suspects to identify the real culprit. The scientist tries to eliminate possible solutions to find the real solution to a scientific problem. In between the two methods stands deductivism: according to this method a scientist makes a hypothesis - a bold conjecture - and then submits it to rigorous tests.

Part B of this Episode concentrates on imaginary and real experiments in the modern era. I introduce Foucaults' famous pendulum experiment (1859), which gave a visual demonstration that the Earth turns on its own axis. I propose that thought experiments answer 'what-if' questions about the natural world. They are models of possible worlds. The episode finishes with a discussion of the famous double-slit experiment on the atomic level. It started out as a mere thought experiment before becoming an iconic a real experiment. It demonstrates the weird behaviour of quantum particles, i.e. the wave-particle duality.

Episode 13 (A, B) is devoted to the topic of experiments in science: thought experiments and real experiments. They are as important as grand scientific theories. Part A focuses on thought and real experiments from antiquity to the 17th century. I explain the function of such experiments and discuss some famous examples. How do you 'prove' that the universe if infinite (Archytas of Tarentum, ca 430-345 BC), that the Earth rotates (Aristotle and Galileo) and how do you measure its circumference (Erastothenes, 240 BC), when you cannot make direct measurements? Listen to Part A to find out!