Showing posts with label science. Show all posts
Showing posts with label science. Show all posts

Tuesday, May 3, 2011

Realism vs. Instrumentalism

A long philosophical debate, which is perhaps my most favourite topic in philosophy, is the issue of realism vs. instrumentalism of science. I find this issue fascinating not only because my career is centred around science, but also because it effectively covers many essential principles of metaphysics and epistemology.

Realism is the view that the theories of science and the entities they introduce really describe what actually exists in nature. In other words, based on scientific realism, atoms, electromagnetic waves, quantum phenomena, fundamental particles, and all other such entities really exist (as long as the scientific theory is true of course). Opposite to realism, there is anti-realism, which suggests these theories and entities do not correspond to the objective reality of entities in nature.

On the contrary, scientific instrumentalism has a very different approach to the theories and entities introduced by science. Instrumentalism sees the focus of realism as irrelevant and instead suggests that science is an instrument and it should be evaluated based on how good it can produce predictions and usable results. This is the view that I have come to support after much thinking.

Before addressing the fundamental philosophical problem with realism, I want to explain a very concrete problem with the scientific method without going to existential and metaphysical discussions. Let’s just examine the scientific method. It is explained in many shapes and forms, but without going to too much detail, the scientific method consists of identifying some problem (observation, inquiring, gathering data), forming a hypothesis, deducing the logical consequences of the hypothesis, and empirically testing those predictions which then either confirm or disprove the hypothesis after many trials and ideally numerous predictions. It is immediately obvious that science inherently depends on logic and human reasoning. The connection between a testable prediction and a theory is entirely based on reasoning alone. For example, electromagnetic waves are a conceptual entity. One cannot test the existence of an abstract entity. Instead, human reasoning is used to connect that idea to a testable prediction. Even if one accepts that there is an objective reality, it is not determined whether our reasoning connects the “right theory” to the “right prediction”. But I must admit that I am not entirely confident on this issue because it can be argued that logic itself is an empirical science. But when was the last time you empirically tested a theorem in your mathematics class (whatever that means)? This issue of the origin of logic is an interesting one which I like to pursue further, but as far as I can tell mathematics does not seem empirical to me. Thus, the whole scientific method as a means of discovering some “objective reality of nature” breaks down.

However, I find a deeper problem with the realistic point of view, and this is more of a metaphysical approach. In other to attempt to find out whether science corresponds to reality, we must clearly define what we mean when we ask whether an entities “exists”? One can define existence based on perception or based on reasoning. In other words, I can define existence such that something exists if I perceive it, or it exists if I think it. So let’s backtrack a little and see what it is we are trying to answer and thus come up with a good definition. I want to find out whether scientific entities correspond to the outer world that I experience around me. So what is the outer world? Let’s start from what I know. I know that I am some conscious agent. That is all I know. Next, I observe a world around me. Of course what I observer does not necessarily exist in the sense that I do as a conscious agent. All of this world, including other seemingly conscious agents, are all in my perception and can be anything… an illusion, a dream, a virtual reality, etc. Now, I do not have access to anything outside of my perception and so I define knowledge within my perception. So at first it seems that a good definition for existence is direct perception. However, it quickly becomes obvious that the world around me is not what I directly observe it to be. For example, 5 years ago something funny happened. The universe got fuzzy and so I started wearing glasses so I can operate better in the transformed, fuzzy universe. But my reasoning tells me that the universe did not change, but it was my eyes, my perception, that changed and that belief shapes my reality. Another example is what we call optical illusions. In the case of optical illusions, such as holograms, my reality does not come from direct observation but again from reasoning and observation together. The point is that in constructing my reality, perception and reasoning are inseparable. So ultimately I am a conscious agent and the reality around me is a reality constructed in my mind through my perception and reasoning. With this definition of reality, how does science correspond to reality? The answer is that science creates reality. When I see the effects of atoms under the microscope, my perception and reasoning create a new reality. This is exactly analogous to the examples I gave earlier. Therefore, any scientific theory becomes a new reality, and the realism/anti-realism debate becomes completely meaningless. Instead, the focus of science becomes the evaluation of different versions of reality based on their usefulness. The new realities of atoms, electromagnetism, and quantum mechanics (along with all other successful theories) are indeed more superior to their alternatives (so far at least) in the sense that they have been the most useful in making a consistent, predictable, and harvestable reality for the reasoning and perception that created them.

Friday, September 17, 2010

A New Perspective on Reality

I recently posted some stuff about reality and the nature of mathematics and the physical world. My views have changed quite a bit and so I want to discuss the issue of reality in this post.

Before discussing things in the context of reality, one should realize that “reality” is just a construct of our minds. We are provided with inputs from the outside world through our senses and our brains construct reality in a way that satisfies all our input. For example I detect a pattern of excitement on my retinas as well as on my fingers and thus I perceive a keyboard in front of me. There is no “keyboard” on my retinas or fingertips, but I create the idea of a keyboard to make sense of my senses and be able to take action. The bottom-line is that all of reality is just an idea. This idea can get more sophisticated by introducing numbers and mathematical quantities. We have evolved to see things in terms of numbers and quantities and we have developed mathematics to describe, analyze, and predict the world around us. There is no sense in asking if these ideas exist in external reality – there is no answer to that question. All of these ideas (objects, quantities, etc.) are all ways to describe our input and make predictions. As long as these ideas make right predictions, they are considered “real” ideas.

On a separate note I also want to add that physics (or all science for that matter) is not about investigating the nature of these ideas, but rather expanding them. For example, time is a basic idea in “reality”. Physics does not try to tell us what time is. Maybe we can reduce the idea of time to a simpler and more general idea, but the problem stands because the nature of that idea is still questionable. Instead, physics develops the idea of time by measuring it and quantitatively relating it to other ideas to find things like the fact that time is relative. Thus we can only develop our ideas and make a more comprehensive, more accurate, and more predictive reality for ourselves.

Friday, August 13, 2010

The Strange Effectiveness of Mathematics

Lately I have been preoccupied with the rather philosophical question of why we are able to discover physical laws through mathematics; or put another way, why does the universe follow mathematical laws and a consistent line of reasoning. One could also go on to ask if mathematics is a human invention or an independent entity that is being discovered bit by bit by humans

Some say mathematics is a form of language invented for the purpose of formulating and describing the world around us and thus there is no sense in asking why it is so effective. I do not agree with this. Firstly, mathematics is not a language, it is a logic system. Furthermore, what is so interesting and astonishing about the power of math is not that it can describe the world around us, but that it can make predictions. Unlike the other sciences, in physics one can deduce new ideas and principles mathematically. I recommend reading “The Unreasonable Effectiveness of Mathematics in the Natural Sciences” by Eugene Wigner (http://hiperc2.buffalostate.edu/~carbonjo/documents/Wigner.pdf) and its follow-up, “The Unreasonable Effectiveness of Mathematics” by R.W. Hamming (http://nedwww.ipac.caltech.edu/level5/March02/Hamming/Hamming.html) to understand the power of mathematics.

As I was reading different ideas about and nature and relation of mathematics to science, I came across the Mathematical Universe Hypothesis proposed by Max Tegmark. Tegmark’s hypothesis states that our external physical reality is a mathematical structure. Tegmark extends his idea to say every mathematical structure has physical reality and our universe is just one mathematical structure, out of many, that has been complex enough to allow us to evolve in it (anthropic principle). The purpose of this post is not to discuss the details of Tegmark’s ideas (which can be found here:http://arxiv.org/PS_cache/arxiv/pdf/0704/0704.0646v2.pdf) but to discuss my own thoughts in regard to the questions proposed in the beginning of this post. The source and effectiveness of mathematics are no longer puzzling if, as Tegmark says, “our universe is mathematics in a well-defined sense.” After all, the universe follows mathematical logic and physicists follow this line of logic to discover how nature works. Maybe developing mathematics is ultimately a journey of discovery – a unique form of discovery which progresses through creativity in the use of the logic that comes to us from nature.

One of the challenging ideas about this school of thought is the relationship of mathematical equations and their interpretations. I find one good example of this to be the equations of quantum mechanics. Our mathematical model of quantum mechanics seems to accurately describe what happens at the quantum level, and their implications have been consistently proven. Yet, there are many interpretations of quantum mechanics that attempt to give some physical meaning to the mathematics of the theory. If the universe is a purely mathematical construct, then there should not be different candidates of reality arising from a single mathematical theory. If this is true, then surely there is more than mathematics to the reality and truth that physicists attempt to understand. However, I do not believe this to be the case. The important point important point is that each scientific interpretation assumes a different and distinguishable mathematical structure. For example, in quantum mechanics the Many Worlds interpretation introduces a unique mathematical system in which the collapse of the wave function is associated with splitting the universe into mutually unobservable, alternate histories—distinct universes within a greater multiverse.Obviously this is a completely distinct mathematical landscape than the Copenhagen interpretation for instance. Therefore, the existence of many interpretations for the same set of mathematical laws is not because mathematics does not completely define reality, but the fact that we do not have the complete mathematical landscape of reality. In fact, conceptual and non-mathematical ideas are just shortcuts for us to examine possible mathematical structures, which will be proven right or wrong through experimentation or further mathematical reasoning as other laws get discovered. All in all, conceptual interpretations are a starting point to get to the ultimate mathematical reality, not the other way around.

Monday, May 10, 2010

Computing a Theory of Everything

Stephen Wolfram has initiated an interesting approach in studying the physical universe. He tries to create our physical universe out of the much more diverse computation universe, the vast abstract universe of computation and mathematics.

Wolfram has created Mathematica and Wolfram|Alpha, two very powerful mathematical/computational tools. He is also the author of "A New Kind of Science" (which is available online). Wolfram has established a new kind of science (as he calls it) which examines the complexity of systems from very simple computational rules.

In his talk at TED, he outlines this idea and how it relates to our physical world, in the sense that our seemingly complex universe could be the product of simple rules which could be simulated in computers. Wolfram has done much research on this issue and has actually created universes that come very close to ours.

I personally believe that this approach is very valuable and successful. Our understanding of nature lies in understanding complexity in systems consisting of different parameters. Not only will this approach make contributions to theoretical physics (hopefully), but it will also allow us to understand much more complex systems such as those in biological organisms. Something as complex as the brain can only be studied from this approach.
As a matter of fact, a very interesting field named Computational Neuroscience is being established. Many mathematicians, programmers, neuroscientists, and physicists will come together to study the brain from a computational point of view. I personally cannot wait to see what will come out of this in the upcoming years.

Sunday, May 9, 2010

Some Interesting Quotes

Here is a list of some interesting quotes that I have encountered here and there. I tried to put them in order from my most favourite to least, but it's not that easy. Here is what I came up with:

"It is not complicated; there is just a lot of it."
Richard P. Feynman

"Life is a sexually transmitted disease."
R. D. Laing

"Physics is like sex. Sure, it may give some practical results, but that's not why we do it."
Richard P. Feynman

"Genius is one percent inspiration, ninety nine percent perspiration."
Thomas A. Edison

"In science one tries to tell people, in such a way as to be understood by everyone, something that no one ever knew before. But in poetry, it's the exact opposite."
Paul Dirac (1902 - 1984)

"We must not forget that when radium was discovered no one knew that it would prove useful in hospitals. The work was one of pure science. And this is a proof that scientific work must not be considered from the point of view of the direct usefulness of it. It must be done for itself, for the beauty of science, and then there is always the chance that a scientific discovery may become like the radium a benefit for humanity."
Marie Curie (1867 - 1934), Lecture at Vassar College, May 14, 1921

"It is our choices that show what we truly are, far more than our abilities."
J.K.Rowling