It is a hobby of mine to collect assumptions in the scientific method as I have a personal interest in philosophy in general, and the philosophy of science in specific. I try to keep them to a bare minimum and disprove assumptions, usually analytically. So, in this blog post, I am going to list some assumptions general to the scientific method that I do not think the method would work without, and give some commentary. I would appreciate input on the assumptions listed, as well as suggestions for further assumptions.
If there are Laws in nature, then those laws do not change with respect to time or space.
I don't think its necessary to assume that Laws do, in fact, exist, because science is a inductive process based in empiricism. So, if Laws exist, we will observe them -- they are not assumed to exist. However, because of the nature of science to build on the work of others, and because it sometimes takes time to fully understand the limits of a theory (Look at Newton)
, we assume that the Laws do not change from one time to another. They are, in this sense, eternal. I think it is better to state the assumption like this than to say that "Time Exists" or
"Space Exists" or "Laws Exist", because these are things that are either difficult to define outside of empirical definitions, or they are things that we do not know exist. If Time does not exist, then of course the laws won't change with respect to time, because a non-existent entity can't effect an existing one. It also doesn't presuppose that we will actually find order in the universe. We hope to find order, sure, but we can't say that we will find order without performing an experiment.
Our Physical World is Deterministic
This is an assumption that I've come to question as of late. I state "Physical World" because science only deals with the physical world. Further, the scientific method does not deal with any other possible physical world, but the one in which we live, because that is the only one which we can empirically verify, which is the highest form of verification in scientific inquiry. However, the term "Deterministic" is one that requires a bit of elucidation.
If by "Deterministic" all we mean is "Physical Laws can not be violated" then I am fine with the assumption of Determinism as an assumption (or, really, that's more of a definition). However, philosophically speaking, Determinism has a much wider meaning. Generally it means that every event from the beginning of time was determined before all events occurred. This can be demonstrated with a Thought Experiment: Supposing we know the physical laws of a photon, and we are present to observe the beginnings of the universe, then we can determine, through a long series of calculations, exactly where the photon is going to go.
However, I do not think we assume Determinism. I think by saying that Determinism is a major assumption in the scientific method, we're putting the cart before the horse. Rather, the evidence amassed through the scientific method suggests that our physical universe is a deterministic one. However, even within the confines of Monism (that the universe does not have any parrelel realities that act in different ways. Generally compared to Dualism, which is generally attributed to Descartes), and that Monism is our Physical Universe, things aren't necessarily deterministic in the grand sense that everything is predetermined before it happens. Rather, it is deterministic in the sense that physical laws can not be violated, and so action is limited, but only within the confines of physical laws, not completely Deterministic as it is usually defined.
There is a Truthful connection between our mind and the Universe
This is a recent one I came upon, so I haven't thought about it as much. It basically assumes that science, in general, is coming closer to the truth about things, rather than the truth about the way we think about things. There is no logical reason for assuming this, but it seems to be working so far. It's the sort of assumption one makes if they either believe in Dualism, or are not purely empirical, such as that demonstrated by David Hume. Science, dealing with Induction to understand data, and Deduction as means for formulating Hypothesis's and understanding of several Induction's, does not only deal with pure empiricism. Rather, it hops between "Types". These types are somewhat separate unto themselves and can be regarded as "Methods to Knowledge".
EDIT: Going through these posts again, I've realized that I've changed the most on this post. I fully disagree assumption 1 and 2, and I think "assumption" 3 can be well argued for, and therefore doesn't count as an assumption -- though it may have to be argued for in a "philosophic" sense, so it may still be an assumption within the domain of science if one accepts that these things are distinctly different at this point.
Monday, June 29, 2009
Wednesday, June 3, 2009
Colloids
With summer comes employment, and with employment comes less learning, and with less learning comes less blogging. In addition, my summer studies are centering around broader philosophical studies than what is topical for this blog, so expect a decrease in posting for the summer months.
However, during a pub-crawl with my friends a few weeks ago, the subject of colloids came up. I poured the beer out too fast, and it foamed over. I knew foam to be a colloid, I knew alloys to be colloids, but I had no recollection of what distinguished a colloid from a solution. Both are heterogeneous mixtures of substances with molecules dispersed fairly regularly throughout a medium. Generally, solutions are liquids that have solids dissolved in them, though they can also have a combination of liquids. Colloids don't have a specified state: In fact, the type of colloid depends upon the states of the dispersion medium (analogous to the solvent) and the thing being dispersed through that medium (analogous to the solute). So, really, in a prima facie way, it seems that colloids are just a more general terminology for solutions.
So I broke out my gen-chem book, and found out I was mistaken -- the difference between colloids and solutions is the size of the molecules, or groups of molecules. In both, a molecule or ion is solvated, or completely surrounded by the solution. But in a colloid, the groups of molecules are much larger, between 1 * 10^3 pm to 1 * 10^6 pm (picometers). For comparison, the bond length of a Helium to Helium molecule is 300 picometers. Another common example of a colloid is found in soap -- when soap molecules interact with grease, they embed into the grease while keeping a single part of the soap molecule on the outside of the grease. The part embedded in the grease is attracted to oily things, and the part on the outside of the grease is attracted to water -- so running water will then push the grease along. This is a colloid composed of a clump of molecules attracted to each other, but dispersed in another medium, and much larger than a molecule in a solution. Another good day-to-day example of colloids can be seen if you go for a walk at the park. If you've seen light streaming through the branches, this is because the light is reflecting off of dust in the air. In fact, this is a common way to distinguish between colloids and solutions, and is known as the Tyndall effect (this picture demonstrates a colloid of a solid in a liquid). The molecules in a solution are so small that they don't interfere with the visible light spectrum, but the molecules or groups of molecules in a colloid are large enough to do so.
So this brought me to another question regarding chemical philosophy: While we can observe the Tyndall effect to distinguish between colloids and solutions, do the sizes of the molecules matter very much aside from the fact that they interact with visible light? I've done kinetics experiments revolving around a solutions ability to absorb light. So, even though we can't observe the interaction with our eyes, the molecules do still interact with light, don't they? Is the terminology of solutions a bit too simplistic? After all, there is a point in solutions where you have to ask, what is the solvent and what is the solute? What if you have more than two liquids and a solid? Proteins can grow to reach sizes like this, and yet they are only one molecule solvated by water. Does that make our DNA colloidal, and what point does this distinction elucidate? After all, we could also just say that solutions with really big particles in them interact with the visible light spectrum and be done with it. But then we'd be expanding the terms of solution to include things that are clearly not mixed in the same way that salt water is mixed, such as mayonnaises, or beer foam. But they are also slightly different from a solid block of, say, iron. But just because there seems to be this odd in between zone where we're uncertain about how to classify and understand given solutions, it seems rather ad-hoc to just make up a term and rationalize a distinction. So, what's the point of colloids, and what terms should we use in distinguishing between types of solutions, if indeed we ought to revise them at all? I'm going with the ambiguous and open-ended ending.
However, during a pub-crawl with my friends a few weeks ago, the subject of colloids came up. I poured the beer out too fast, and it foamed over. I knew foam to be a colloid, I knew alloys to be colloids, but I had no recollection of what distinguished a colloid from a solution. Both are heterogeneous mixtures of substances with molecules dispersed fairly regularly throughout a medium. Generally, solutions are liquids that have solids dissolved in them, though they can also have a combination of liquids. Colloids don't have a specified state: In fact, the type of colloid depends upon the states of the dispersion medium (analogous to the solvent) and the thing being dispersed through that medium (analogous to the solute). So, really, in a prima facie way, it seems that colloids are just a more general terminology for solutions.
So I broke out my gen-chem book, and found out I was mistaken -- the difference between colloids and solutions is the size of the molecules, or groups of molecules. In both, a molecule or ion is solvated, or completely surrounded by the solution. But in a colloid, the groups of molecules are much larger, between 1 * 10^3 pm to 1 * 10^6 pm (picometers). For comparison, the bond length of a Helium to Helium molecule is 300 picometers. Another common example of a colloid is found in soap -- when soap molecules interact with grease, they embed into the grease while keeping a single part of the soap molecule on the outside of the grease. The part embedded in the grease is attracted to oily things, and the part on the outside of the grease is attracted to water -- so running water will then push the grease along. This is a colloid composed of a clump of molecules attracted to each other, but dispersed in another medium, and much larger than a molecule in a solution. Another good day-to-day example of colloids can be seen if you go for a walk at the park. If you've seen light streaming through the branches, this is because the light is reflecting off of dust in the air. In fact, this is a common way to distinguish between colloids and solutions, and is known as the Tyndall effect (this picture demonstrates a colloid of a solid in a liquid). The molecules in a solution are so small that they don't interfere with the visible light spectrum, but the molecules or groups of molecules in a colloid are large enough to do so.
So this brought me to another question regarding chemical philosophy: While we can observe the Tyndall effect to distinguish between colloids and solutions, do the sizes of the molecules matter very much aside from the fact that they interact with visible light? I've done kinetics experiments revolving around a solutions ability to absorb light. So, even though we can't observe the interaction with our eyes, the molecules do still interact with light, don't they? Is the terminology of solutions a bit too simplistic? After all, there is a point in solutions where you have to ask, what is the solvent and what is the solute? What if you have more than two liquids and a solid? Proteins can grow to reach sizes like this, and yet they are only one molecule solvated by water. Does that make our DNA colloidal, and what point does this distinction elucidate? After all, we could also just say that solutions with really big particles in them interact with the visible light spectrum and be done with it. But then we'd be expanding the terms of solution to include things that are clearly not mixed in the same way that salt water is mixed, such as mayonnaises, or beer foam. But they are also slightly different from a solid block of, say, iron. But just because there seems to be this odd in between zone where we're uncertain about how to classify and understand given solutions, it seems rather ad-hoc to just make up a term and rationalize a distinction. So, what's the point of colloids, and what terms should we use in distinguishing between types of solutions, if indeed we ought to revise them at all? I'm going with the ambiguous and open-ended ending.
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