It's (Meta)Physics, Stupid! Trivia Quiz

Answer: The rational investigation into the principles of knowledge

My perceptions of philosophy at the time were admittedly based around the more stereotypical philosophical quandaries - "is there a God?" "How do we know that 2+2 = 4?" etc. I saw promise in the idea of questioning concepts, but how could doubting whether 2+2 = 4 do anything but hinder the progress of science? Particularly one so mathematically based as physics! I soon came to realise, however, that questions like "How do we know 2+2 = 4?" are not necessarily meant to be taken literally, but are intended to be an introductory mechanism to get novices (like myself) into the philosophical mind-set.

It is important (scratch that, it is essential) in science to constantly question what may be considered as dogma. For 33 years after Theophilus Painter mis-counted the number of chromosomes in a cell on his glass slide, humans were believed to have 48 (rather than 46) chromosomes. By questioning what is "known" in science, we are taking necessary pit-stops which helps to prevent us becoming stuck in more stagnant circumstances.

Answer: True

Philosophy once incorporated the sciences of biology and physics, which were collectively known as natural philosophy. Indeed, the vestiges of this connection are still seen in the students who earn PhDs in molecular biology or particle physics - they are in fact becoming "doctors of philosophy".

Moreover, the word "philosophy" literally means a "love of knowledge", which can be applied to any self-respecting scientist. But aren't these just words? Clearly there was a reason why physics came to be a separate subject from philosophy.

The terms "physics" and "philosophy" have evolved with time and what they represent now are different to what they represented several hundred years ago (particularly the former). The experimental apparatus available in the modern age allows us to observe greater amounts of empirical evidence rather than trying to resolve physical concepts using our minds alone.

This reasoning, however, only proves (at best) that physics and philosophy are not the same. It does little to add to the argument that the two subjects are opposites of one another, or are incompatible.

Answer: Mathematics

It is believed that statements can be synthetic or analytic. Synthetic statements require evidence to validate them (for example, saying that it is raining outside cannot just be believed through pure logic, it requires you to look out of the window and see for yourself). In contrast, analytic statements do not require evidence in order for us to know they are true. It is this latter category of statement into which mathematics falls. Mathematics is based on sets of rules and so mathematical statements such as "2+2 = 4" do not require you to go out and get two lots of two things to prove that they make four - you can accept this statement to be true without such evidence. The concept of mathematics is therefore an important illustration of logic in philosophy, as discussed in Bertrand Russell's "Principia Mathematica". Russell was himself both a philosopher and a mathematician.

Physics is a subject clearly based around mathematics. It is difficult to think of a physical concept that cannot be reduced to mathematical equations. If we accept that logic is a central concept of philosophy, and that mathematics is key to physics, the statement that mathematics is logic means these two subjects - physics and philosophy - share a common core.

Answer: Empiricism

Empiricism was based around the concept that knowledge is derived purely from sensory experience. Such sensory experience includes feeling that a stone is in your hand, or seeing that a car is in front of you. Based on this empirical evidence both the stone and the car exist. There are clear similarities between this approach and that employed by physicists. As implied in the question, physical laws are not ones that are just thought up because they make sense. Physicists start with a hypothesis, and then perform experiments to try and disprove this hypothesis. With the data they collect from these experiments, they can then decide whether to accept or reject the hypothesis.

Clearly, empiricism is just one philosophical school. It stands in contrast to rationalism, which holds that knowledge is based on intellectual reasoning, rather than experience (just think of Descartes' "I think, therefore I am"), which was so derided by the physicist Richard Feynman. This does not thwart the link between physics and philosophy, however. The fact that such a school as empiricism exists is reason enough to overthrow the opinion of my younger self that physics and philosophy belong at opposite ends of the spectrum.

Answer: Gottfried Leibniz

Leibniz believed that the world was made up of physical and mental entities. While physical entities occupied space (an important principle in physics!), mental entities did not. However, if a physical entity was divided into its constituent parts, and then sub-divided further and further until it could not be divided anymore, it formed entities called monads. These monads were indivisible and so occupied no space. By definition, then, they are mental rather than physical. Leibniz therefore concluded that all things are mental.

It is true that Leibniz was a gifted mathematician (he independently developed calculus), but the principle of reducibility of matter pre-dated even his by several hundred years. The pre-Socratic Greek philosophers Democritus and Leucippus were the first people known to suggest that matter was composed of atoms. While it is doubtful that they conceived atoms as being the same thing as we understand them today, the arrival at such seemingly unknowable conclusions through logic alone proves Richard Feynman wrong when he stated that things could not be discovered through thought processes rather than experiment.

Answer: Idealism

Idealism is similar in some senses to empiricism, but it goes one step further by saying that things that you do not observe are non-existent. If a tree falls in a forest and no one is around, an idealist will tell you that it won't make a sound, and that it wasn't even there in the first place! Bertrand Russell directly addressed these issues with idealism by providing the example of a table.

He looks at the table and so it exists (according to the idealist). If he then puts a table cloth over it, the table suddenly no longer exists. Russell argued that common sense is used to inform that this table-shaped table cloth is not floating in the air, but instead has a table under it.

The table exists. This weakness of idealism was addressed by one of its most famous followers, George Berkeley, who gave the convenient excuse that since God observes everything, all things exist even when no human is observing them.

Answer: David Hume

These ideas of David Hume were repeated by one of the greatest minds in physics in recent history, Richard Feynman. In one of Feynman's televised lectures, he sets out the basis of the scientific approach. He says that we first "guess" (the audience laughs), we then compute the implications of what this guess would have on nature if it were true, and we then compare these implications to the reality, as deduced from observation/experiment. This may seem like a re-worded version of what I discussed in the II section of question 2, but it precedes Feynman's important concluding statement about this approach - "if it disagrees with experiment, it's wrong". This statement highlights one of the most fundamental aspects of the scientific approach. The more and more evidence you acquire which supports a hypothesis means that the hypothesis is more likely to be true. For example, the hypothesis of Britons in the 17th century that "all swans are white" was supported by the fact that every swan seen by a Brit so far had been white. However, this did not prove the hypothesis that all swans were white. Thousands of white swans cannot prove this, yet it takes only a single black swan to disprove it. Indeed upon arriving in Australia, the observation of black swans caused this hypothesis to be swiftly revised.

The inability of a statement to be falsified, according to the philosopher Karl Popper, means that the statement is meaningless. If a statement is neither true by definition, nor can it be falsified/verified by observation, then it has no meaning. An example often used is that "God exists". This is not true by definition (though those who follow the ontological argument would disagree), nor can it be categorically verified or falsified by experiment/observation. The statement "God exists" is therefore meaningless according to Popper.

Answer: Immanuel Kant

Kant drew a clear distinction between the reality of things, and what we perceive to be reality. He stated that we do not directly experience events, but instead experience our interpretation of these events. Part of this theory claimed that space and time were not part of the external world, but were concepts created by the mind so as to allow it to compute the information it takes in.

The importance here is the challenge to concepts such as space and time as absolute and unchanging. Indeed, Einstein later used mathematical evidence to state that space and time are relative to the observer, as part of his General Theory of Relativity.

For example, a person moving close to the speed of light will appear, relative to a stationary observer, to be extremely short.

The major difference between Kant and Einstein is that Einstein considered space and time to be entities of the physical universe, whereas Kant viewed them as necessary creations of our minds.

Answer: Pragmatism

Science is the acquisition of knowledge in the search for answers to unanswered questions about the natural and physical world. Faced with a set of hypotheses, a scientist will analyse which one is supported by the greatest amount of evidence, and hence which will be the most useful in acting as the basis for performing further experiments to try and justify this hypothesis, or improve upon it. This is pragmatism.

The willingness to accept that one's theory is imperfect is not compulsory and, due to pride, is often rare in science. However, theories and laws, however well supported, will always be imperfect and open to new evidence which can change or even overthrow it. The falsifiability of these scientific laws would therefore be "meaningful" according to Karl Popper. A good example is the Newtonian idea that light always travelled in straight lines. Every experiment done on Earth supported this, and it was difficult to imagine any instance where light would disobey this law. However, light was found to bend when close to extremely massive bodies in space (e.g. black holes). The Newtonian theory of light travelling in straight lines was good (it was more that good - it massively advanced the study of optics), but was not perfect. The finding that light sometimes did not travel as straight lines did not lead to this theory being thrown out of the window with all of the work which was based on its assumptions, but it was merely redefined - light travels as straight lines when in a uniform gravitational field.

Answer: Duality

The authority at the time, Sir Isaac Newton, claimed that light behaved as particles called corpuscles. Due to his standing as a scientist, this belief was held by many to be true. In contrast, Christiaan Huygens thought light was composed of waves and was supported by the double-slit experiment performed by Thomas Young, which demonstrated interference - a quintessential property of waves. However, Einstein later demonstrated the photoelectric effect, which suggested that light behaved as a particle. It was eventually reconciled that light was both a particle and a wave. But how can something be two things at once? Such a dichotomy has led many to view the theory of wave/particle duality from a philosophical stand-point.

Richard Dawkins said that "we evolved to observe medium sized objects moving at medium speeds" making the extremely small (quantum physics) and the extremely large (relativity) very abstract to us. In truth, our senses are humblingly insufficient to understand all of the mysteries of the world. We have to build telescopes and other devices capable of detecting the electromagnetic radiation that our organs cannot. Our interpretation of this data is exactly that - an interpretation - rather than a direct observation, which is wholly analogous to the philosophical ideas of Immanuel Kant concerning how true to reality our observations really are. In this sense, an argument can be put forward that philosophy has a place in modern day science in order to try and rationalise these concepts, though this is disputed by many eminent physicists such as Neil deGrasse Tyson and Stephen Hawking, who declared that "philosophy is dead".

The issue of whether philosophy has a place in modern day physics is therefore disputed, but its importance in the history of physics cannot be disregarded.