Category Archives: measurement

Aether Discontinuity

Assume space-time is quantized.  This would mean that space-time is broken up into discrete bits.  It then follows that time is broken up into discrete bits.

This disagrees with basic experience: we can start counting time at any arbitrary point.  “Now” could be any time whatsoever.  Moreover, we run our physical experiments at any given point; we don’t have to wait to start our clocks.

But what if our ability to run experiments at any given point is just an illusion of our universe being broken up into such tiny bits that we just don’t notice the breaks?

Could we design an experiment to test when we can run experiments?

If time is continuous, we would never find any point at which we could not run an experiment.  If time is not continuous, though, we would likewise never find any point at which we could not run an experiment, since all experiments would use clocks that start within that lockstep quantized time.

Hence we are unable to tell the difference between quantized and continuous time such that it always appears continuous.

However, even if time is continuous in this fashion, measurement of time is not.  Since there is a lower limit to what we can distinguish between two different times, even if we are free to start measuring whenever we want, all subsequent measurements are physically dependent upon that initial fixed point.  The second measurement must be outside the uncertainty associated with the initial measurement (the clock start) and the third must be outside the second, etc.  Therefore all physically useful measurements of time (counting past zero, that is) are inherently physically quantized by their dependence upon the instantiation of measurement and limits of uncertainty.

If time is both continuous and discontinuous in this fashion, then so is all space-time.

This leads to the question of which is ontologically prior: if you hold that our reality is defined by what we can measure, then the universe is quantized and our experience pigeonholed; if you hold that our reality is defined by our phenomenal experience, then the universe is continuous and measurement is pigeonholing.

Either way it is a question of the metaphysics — not physics —  of space-time.  And without a way to distinguish between these options, no physical experiment will be able to settle the debate either, since we could always be chasing our metaphysical tails.


I’ve mulled over this issue concerning the logical limits of what can be measured by physics for years, but I never developed any conclusions.  However, there has recently been discussion of the feasibility of a tabletop search for Planck scale signals.  This nifty experiment seems deviously simple with the potential for novel results, so go check it out if you haven’t heard of it yet, for example in this discussion.  One issue that the experiment bears upon is the continuity of space-time at the Planck Scale.  My worry is that the above metaphysical distinction between counting zero and counting past zero may trip up the physicists’ search for the continuity or discontinuity at the fundamental levels of matter.

Posted in measurement, metaphysics, philosophy, physics, Relativity, science, time.

Book Review: The Genial Gene

The Genial Gene: Deconstructing Darwinian Selfishness by Joan Roughgarden

In The Genial Gene Joan Roughgarden seeks to replace the competitive understanding of evolution, known as sexual selection, with a cooperative one. The first sentence of her book reads, “This book is about whether selfishness and individuality, rather than kindness and cooperation, are basic to biological nature” (p. 1).

So what is the argument? Taking this first line, she wants to conclude something about basic biological nature. To do this, one can either define what basic biological nature is and then use that definition to derive conclusions, or else survey the natural world and find the best interpretation for whatever empirical results were found. She opts for the latter strategy.

To this end she first surveys and compiles examples of what people consider to be evidence for sexual selection and argues that this evidence has been misconstrued or simply does not support the theory of sexual selection. Then she offers a few logical arguments against sexual selection with the aim to highlight contradictions within the theory.

She then develops her alternative, called Social Selection. Social Selection is fundamentally based upon cooperation, not competition, and she proceeds to reinterpret the empirical research with respect to cooperation. Given the results of this reinterpretation, she concludes that the cooperative approach provides a more accurate picture of the empirical data than the competitive approach. Therefore social selection, not sexual selection, is fundamental to biological nature.

Can this argument be maintained?

Her argument fundamentally turns on the interpretation of the empirical research. (If her logical arguments were strong enough to undermine sexual selection on their own, she would have dedicated more space to them. At best, in my opinion, they could raise questions about sexual selection, but are not inherently damaging enough, even if they are accepted uncontested, to force a major revision to sexual selection.) She interprets the research in terms of cooperation and her opponents are those who interpret the research in terms of competition. Roughgarden claims her interpretation is the correct one.

Insofar as she is making an inference saying her interpretation is the best conclusion, her argument fails. She readily admits that the defenders of sexual selection are able to consistently create explanatory fixes for apparent contradictions in the empirical research. Since they are able to explain the data, the fact that she is unsatisfied by their explanations (and likes her own better) is no grounds for convincing her opponents to give up their explanations. After all, they have history and authority on their side. Her coming up with better numbers, that is, having formulas that (she says) more accurately represent the research, is not a sufficient reason for discarding a theory that has held up for many years, especially one that continues to be an area of active research. So, she has not successfully argued that social selection should replace sexual selection.

However, if we consider a more modest conclusion, then Roughgarden may be able to maintain part of her argument. She makes the point that the core Darwinian theory does not include sexual selection; it is a later contribution (ppg. 3-4). This suggest that there may be theoretical room for cooperation in addition to competition. But how much room?

Now the interpretive problem that she set up cuts the other way. Instead of her trying to convince us that her cooperative interpetation of the empirical research is the correct one, we ask the competitive interpretation why it is the best one. Empirical research alone cannot support one conclusion over another: the data must first be interpreted before a conclusion can be reached. As mentioned above, sexual selection has history and authority on its side, but age and endorsements are not arguments for being the sole fundamental methodology of biological nature. Without history and authority, sexual selection proponents only have their ability to explain bioogical research, which is no more than Roughgarden has. Therefore, advocates of sexual selection have no further theoretical resources to support their claim that sexual selection is the fundamental method working in evolution.

This means that Roughgarden does succeed in part. Based on the arguments she provides she is unable to maintain that kindness and cooperation underpin evolution, but she is able to cut sexual selection down to her size. She has shown that it is possible to reinterpret biological research in terms that do not rely upon competition and that sexual selection has no special theoretical privelege. Therefore sexual selection proponents can no longer claim to be fundamental biological reality: even though Roughgarden was unable to fell their theory, they won’t be able to down her either, and so she has established theoretical room for cooperation in Darwinian theory.

Posted in biology, evolution, measurement, science. Tagged with , , , .

Rewrite of Evolution

New theory of evolution!  Hooray!

Patched a bunch of things together to make a nice story.  Fixed the little issue about fitness being circular.  Expanded natural selection to apply more generally.  Causal structure.  Epistemological foundations.  ooOoOO0Ooooooo.

And it’s good fun.  I swear.  Epistemology, history of physics, evolution… makes me happy.  You should really read it.

Download here. [pdf, 304kb]

Posted in biology, epistemology, evolution, fitness, General Relativity, measurement, philosophy, physics, Relativity, science. Tagged with , , , , , , , .

… Yeeeeaaaaaaahhhhhhh

via BackRe(Action)

Posted in fun, General Relativity, measurement, physics, Relativity, science, Special Relativity. Tagged with .

Genetic Drift and the Uncertainty Principle

I have previously argued that the history of species must be treated like a evolutionary trajectory: we can only appreciate a species in a relative sense, just as we must evaluate physical trajectories relative to our own motion.

But what happens when we try to measure the very small in physics?  We find there is a limit to the precision at which we can measure, as given by the uncertainty principle.

This suggests that there may be some similar limit when it comes  to measuring small changes in species.  The more we try to pin down exactly what a species is, the less sure we will be about its future and the more we measure the direction the species is heading, the less sure we will be about exactly what constitutes that species.

If genetic drift is just another way of saying that we cannot pin down the exact genetic make-up of a species then drift may be considered to be an instance of the uncertainty principle.

and HAPPY NEW YEAR

Posted in biology, evolution, measurement, philosophy, physics, Relativity, science.

Dismantling Fodor’s Argument

Fodor argued that the theory of evolution is not a legitimate theory of science because it is either vacuously true or wrong.  He accused Darwin of committing the intentional fallacy. (synopsis here)

Insofar as he made no logical mistakes in his reasoning, we need a different strategy to defend the theory of evolution.  In this post I will argue that his argument is an instance of gerneral underdetermination, and hence not a problem of evolution but of philosophy of science.

Underdetermination means that we can’t specifically identify the exact cause of scientific phenomena.  For example, given some phenomenon, say darkness during the day, there can be many possible explanations: an eclipse, an exploding volcano shooting ash into the air, the sun has gone out, the electric company has blocked the sun to make more money, it was the work of Claw Vipers, etc.  The exact cause of the darkness is underdetermined; sure we can research the problem and eliminate some of the possible explanations, but because of our limitations we will never be able to check everything.  So the cause of the darkness can be said to be underdetermined, i.e. there is just not enough determining evidence.

Fodor argues that the theory of evolution is vacuous becuase given any trait we identify as benficial to the fitness of the organism is arbitrarily selected.  Since there are too many factors to identify within an ecosystem or organism acting within that ecosystem, any hypothesis we propose about the fitness of that organism in that ecosystem will be trivially compatible with evolution.

For example assume there is an argument that having a certain trait, say longer legs, increases a zebra’s fitness.   We can recognize that this argument could be unfounded because it might not be the longer legs but something else that increases the zebra’s fitness.  It just happened that increased leg length was a harmless side affect of this truly beneficial trait.  Either way, if it is the longer legs or some other unidentified trait, evolution is always compatible with our theories, and so it is trivially vacuously true.

In short I would say that he is arguing the cause of natural selection is underdetermined.  The task is to identify whether this is a unique case of underdetermination or an instance of general underdetermination.  I will now show that this sort of underdetermination can exist in physics*:

Imagine we are doing physics and we want to know which of two metal ingots is the more massive.  We pull out our scale, place each object on one of the trays and wait for the scale to indicate which is the more massive.

Why does the scale tip in the direction of object A?  We could argue that object A has a trait, it is composed of iron, and that trait makes it more massive than some other object.  However, maybe object B is connected to a helium balloon.  Maybe there is a gravitational anomaly in the location where we are doing our experiment.  Maybe the iron is magnetized and there is another ingot with the opposite polarity under the table.  Maybe a God is tampering with our experiment with a noodly appendage.  Feel free to make up as many of these as you want.  There any number of reasons why one object could tip the scale in its favor, and being more massive is among them, though selecting this as the reason is arbitrary.

(One of the things that is wrong here is that we don’t expect General Relativity to predict which objects are more massive.  The mass of an object is the result of the history of its creation and ‘life’ up till the point we measure it.  We do expect Relativity to suggest methods for testing such claims, which it does.  Likewise Evolution should not be expected to predict which organism is fitter, but to suggest methods for testing fitness.)

If I now recast Fodor’s criticism into physical terms, in reference to the above thought experiment, this is the result: The theory of General Relativity (gravity) is vacuous because any given trait we identify as increasing the mass of an object is arbitrarily selected.  Since there are too many factors to identify within a physical system, any hypothesis we propose about mass of the object in that physical system will be trivially compatible with General Relativity.

Therefore physics suffers from the same kind of underdetermination that Fodor accused of evolution.  Anyone who persists in disbelieving evolution on these grounds should also deny General Relativity.  Of course this is excessive: since the underdetermination criticism goes to the heart of our scientific theories in general, it is a problem of philosophy of science and not a problem of biology or physics specifically.  Insofar as underdetermination remains an issue within the philosophy of science we still have to take it into consideration, but this should not be seen as a reason to think our current scientific theories are wrong.

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[EDIT:  I’ve put up a new analysis (24 March 2010) of Fodor’s argument here: Hypotheses Natura Non Fingo]

See a continuation of the argument against Fodor in What Fodor Got Wrong, and in Fodor’s Intensional Criticism of Evolution.

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* This is the argument I presented Fodor with during our brief conversation after his talk at CUNY.  He tried to block it by saying that Natural Selection is statistical, whereas General Relativity is not.  In my previous post, What Fodor Got Wrong, I argued that this position begs the question or is just wrong.

Posted in biology, evolution, fitness, General Relativity, measurement, philosophy, physics, science. Tagged with , , , , , , , .

Time and the Limits of Science

Measurement takes time; measurement is a process.  So the measurement of time immediately yields this theoretical issue:

Since measurement takes time, our ability to break time into ever smaller pieces will always be proportional to the method of measurement used.  The faster our measurement device that measures time, the more divisible time will be.  Insofar as there are limits to how fast a measurement process can occur (relativistic or other), there will be limits on the lengths of time we can measure. From this perspective, time is discontinuous: there will be a point at which we can no longer split time into smaller pieces.

From a different perspective, time must be continuous: we can start our measurement of time whenever.  Since there are no restrictions on when our measurement may begin, each and every instant must be just as good as every other instant, hence time is continuous.

So which is it: Is time continuous or discontinuous?

Or is the question badly formed? The discontinuity argument is based upon the ideas of measurement and relativity.  The latter argument, for continuity, is based upon what might be considered a fact of modal reality.  Perhaps the two arguments are not talking about the same thing.

I can’t give an end-all be-all answer to the questions of time, but here is my opinion:   Time is continuous, but when we start to do scientific activities, time can and will only be able to be measured discretely.  Therefore the two arguments are not using one word to describe two different phenomena.

The question then becomes how doing science limits what we can observe.

This might sound like an extremely unlikely situation, but consider the case of organized sports.  When playing a sport or game you are bound, restricted, to following certain rules.  However, by following these rules, you and the other players can demonstrate skills and abilities that you otherwise would not have been able to observe:  Lots of people may be in shape, but only a small fraction of those people are professional athletes.  Those athlete demonstrate their superior physical and mental prowess by performing on the game field by being restricted by the official rules.

Getting back to science, does it now seem so unlikely that we restrict ourselves in certain ways in order to accomplish other tasks?  For time to be scientifically useful, we need to have some sort process that has a fixed point from which to start counting from, and a unit to count.  Then we can compare an unknown process to this known process, and we have done so with much success.

This comparison could not have occurred without the introduction of an arbitrary fixed point and unit of measurement: by restricting our concept of time to these particular processes we enable ourselves to perform scientific research.  Research is not possible if we use the unrestricted modal notion: no comparison can be made because there is no inter-modal process to compare a worldly (intra-modal) phenomenon to.  But with the use of fixed points, units and processes, we also become subject to relativistic limitations.  It seems like a very small price to pay considering the success of science.

To sum up: time is subject to modal considerations, which gives it special properties such as being continuous.  Once we start to do science, though, we restrict ourselves to the non-modal aspects of time, which allows us to use it as a tool in scientific research.  This also makes time appear to have different properties, but upon closer study, these properties are artifacts of the measurement process and not time itself.

Posted in measurement, ontology, philosophy, physics, Relativity, science, time. Tagged with , , , .

something about time

There is something about time that I can’t seem to stop thinking about.

We measure time by agreeing upon an event and then counting from that point onward.  Today is October 17, 2008 AD.  It is this AD that keeps my attention.  It has been 2008 years, ten months and seventeen days since the birth of Jesus of Nazareth: AD stands for Anno Domini, or year of our lord.  Those not wanting to be explicitly Christian use CE, which stands for Common Era, which is just a nice way of saying the same thing without recognizing Jesus as the lord.  Wikipedia dates the use of this term to 525 AD, though this is how everyone has been measuring time forever. AD began to be used in 525, but before that people just used other events (like natural disasters, battles worn or lost, etc.) as starting points to count the date from.

The only result is that time is not universal but relative to whenever people agree to start counting from.  This is nothing new, but maybe like The Ring, if I pass it along, then it won’t bother me any more.  If you become similarly afflicted, I apologize, but you know what to do.

Posted in measurement, Relativity, science, time. Tagged with , , , .

Where Does Probability Come From? (and randomness to boot)

I just returned from a cruise to Alaska. It is a wonderful, beautiful place. I zip-lined in a rain forest canopy, hiked above a glacier, kayaked coastal Canada and was pulled by sled-dogs. Anywho, as on many cruises, there was a casino, which is an excellent excuse for me to discuss probability.

What is probability and where does it come from? Definitions are easy enough to find. Google returns:

a measure of how likely it is that some event will occur; a number expressing the ratio of favorable cases to the whole number of cases possible …

So it’s a measure of likelihood. What’s likelihood? Google returns:

The probability of a specified outcome.

Awesome. So ‘probability as likelihood’ is non-explanatory. What about this ‘ratio of favorable cases to the whole number of cases possible’? I’m pretty wary about the word favorable. Let’s modify this definition to read:

a number expressing the ratio of certain cases to the whole number of cases possible.

Nor do I like ‘a number expressing…’ This refers to a particular probability, not probability at large, so let’s go back to using ‘measure’:

a measure of certain cases to the whole number of cases possible.

We need to be a bit more explicit about what we are measuring:

a measure of the frequency of certain cases to the whole number of cases possible.

OK. I think this isn’t that bad. When we flip a fair coin the probability is the frequency of landing on heads compared to the total cases possible, heads + tails, so 1 out of 2. Pretty good.

But notice the addition of the word fair. Where did it come from, what’s it doing there? Something is said to be fair if that thing shows no favoritism to any person or process. In terms of things that act randomly, this means that the thing acts in a consistently random way. Being consistently random means it is always random, not sometimes random and other times not random. This means that fairness has to do with the distribution of the instances of the cases we are studying. What governs this distribution?

In the case of of a coin, the shape of the coin and the conditions under which it is measured make all the difference in the distribution of heads and tails. The two sides, heads and tails, must be distinguishable, but the coin must be flipped in a way such that no one can know which side will land facing up. The shape of the coin, even with uniform mass distribution, cannot preclude this previous condition. Therefore the source of probability is the interdependence of physical conditions (shape and motion of the coin) and an epistemic notion (independence of knowledge of which side will land up). When the physical conditions and our knowledge of the conditions are dependent upon each other then the situation becomes probabilistic because the conditions preclude our knowing the exact outcome of the situation.

It is now time to recall that people cheat at gambling all the time. A trio of people in March 2004 used a computer and lasers to successfully predict the decaying orbit of a ball spinning on a roulette wheel (and walked out with £1.3 million). This indicates that after a certain point it is possible to predict the outcome of a coin flipping or a roulette ball spinning, so the dependence mentioned above is eventually broken. However this is only possible once the coin is flipping or the roulette ball is rolling, not before the person releases the roulette ball or flips the coin.

With the suggestion that it is the person that determines the outcome we can expand the physical-epistemic dependence to an physical-epistemic-performative one. If I know that I, nor anyone else, can predict the outcome until after I perform a task, then the knowledge of the outcome is dependent upon how I perform that task.

This makes sense because magicians and scam artists train themselves to be able to perform tasks like shuffling and dealing cards in ways that most of us think is random but are not. The rest of us believe that there is a dependence between the physical setup and the outcome that precludes knowing the results, but this is merely an illusion that is exploited.

What about instances in which special training or equipment is unavailable; can we guarantee everyone’s ability to measure the thing in question to be equal? We can: light. Anyone who can see at all sees light that is indistinguishable from the light everyone else sees: it has no haecceity.

This lack of distinguishability, lack of haecceity (thisness), is not merely a property of the photon but a physical characteristic of humans. We have no biology that can distinguish one photon from another of equivalent wavelength. To distinguish something we have to use a smaller feature of the thing to tell it apart from its compatriots. Since we cannot see anything smaller, this is impossible. Nor is there a technology that we could use to augment our abilities: for us to have a technology that would see something smaller than a photon would require us to know that the technology interacted at a deeper level with reality than photons do. But we cannot know that because we are physically limited to using the photon as our minimal measurement device. The act of sight is foundational: we cannot see anything smaller than a photon nor can anything smaller exist in our world.

The way we perceive photons will always be inherently distributed because of this too. We cannot uniquely identify a single photon, and hence we can’t come back and measure the properties of a photon we have previously studied. Therefore the best we will be able to accomplish when studying photons is to measure a group of photons and use a distribution of their properties, making photons inherently probabilistic. Since the act of seeing light is a biological feature of humans, we all have equal epistemological footing in this instance. This means that the epistemic dependence mentioned above can be ignored because it adds nothing to the current discussion. Therefore we can eliminate the epistemic notion from our above dependence, reducing it to a physical-performative interdependence.

Since it is a historical/ evolutionary accident that the photon is the smallest object we can perceive, the photon really is not fundamental to this discussion. Therefore, the interdependence of the physical properties of the smallest things we can perceive and our inherent inability to tell them apart is a source of probability in nature.

This is a source of natural randomness as well: once we know the probability of some property that we cannot measure directly, the lack of haecceity means that we will not be able to predict when we will measure an individual with said property. Therefore the order in which we measure the property will inherently be random. [Assume the contradiction: the order in which we measure the property is not random, but follows some pattern. Then there exists some underlying structure that governs the appearance of the property. However, since we are already at the limit of what can be measured, no such thing can exist. Hence the order in which we measure the property is random.]

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If I were Wittgenstein I might have said:

Consider a situation in which someone asks, “How much light could you see?” Perhaps a detective is asking a hostage about where he was held. But then the answer is, “I didn’t look.” —— And this would make no sense.

hmmmm…. I did really mean to get back to gambling.

Posted in biology, epistemology, evolution, fitness, independence friendly logic, logic, measurement, mind, philosophy, physics, Relativity, science, Special Relativity, technology. Tagged with , , , , .

Relativity as Informational Interdependence

Ever have the experience of sitting in traffic and believe that you are moving in reverse, only to realize a second later that you were fooled by the vehicle next to you moving forward? You were sitting still, but because you saw something moving away, you mistakenly thought you started to move in the opposite direction.

Two different senses may be at work here: your sight and your balance. Lets assume that your balance did not play any role in this little experiment (you would have been moving too slowly to feel a jolt). Your sight told you that you were moving in a certain direction (backwards) because of something you saw, say a bus pulling forward. Then you saw something other than the bus, say the ground, and you realized that your initial appraisal of the situation was incorrect.

At the point when you look away from the bus, you believe that you are moving backwards. Then when you see the ground, you believe that you are not moving backwards. You reconcile these two contradictory beliefs by deciding that it was not you who were moving backwards but the bus that was moving forwards.

What this illustrates is that objects require something other than themselves to be considered in motion. Without the ability to reference a ‘stationary’ system (the ground), it is impossible to make a determination who is moving and who is staying still.

Now imagine this situation was taking place in a very gray place. The only things visible are yourself and the bus on a gray background. Then you notice that the bus is getting smaller. There is nothing for you to use as a reference (no stars, no ground, no nothing) to decide if it is you who is moving away from the bus or if it is the bus moving away from you, or both*. The only thing you have is the information that you and the bus are moving away from each other.

I refer to the statement that you and the bus are moving away from each other as information and not a belief because it is much more certain than what I called beliefs above, namely that you were in a certain kind of motion, which quickly turned out to be questionable.

The information that you and the bus are moving away from each other is not your everyday sort of information. It would be inaccurate to reduce this statement to a conjunction (you and the bus are moving), which is incorrect, or a disjunction (you or the bus is moving) because you are only moving with regard to the bus. By claiming that either you or the bus is moving, it makes it seem that the motion of one has nothing to do with the other. The motion of you and the bus need to be mutually dependent upon each other, and a mutual interdependence is not reducible.

If we return to the everyday, we can say that you have the information that you and the bus are moving away from each other and you and the bit of ground you are on are not moving away from each other. Since the bit of ground we initially selected was arbitrary (we could have chosen anything, like another bus) it is subject to the same issues as the bus; we merely take the ground to be stationary for most purposes, but this is a pragmatic concern. Hence all determinations of motion (or non-motion) are instances of informational interdependence.

The result that relativity is part of a larger class of mutually interdependent structures is non-trivial. Minimally this formalism will allow us to specify exactly when the use of relativity is warranted, but more importantly it will allow us to identify and provide insight into other situations of informational interdependence. Cases of mutual interdependence are relatively rare as far instances of logic go (they can’t even be described in first order logic) and having such a well studied example gives us a head start on this phenomenon.

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* or if the bus is shrinking, or you are growing, or all of the above, but lets assume no Alice in Wonderland scenarios.

Posted in independence friendly logic, logic, measurement, philosophy, physics, Relativity, science. Tagged with , , , .