## Posts tagged ‘subjectivity’

November 11, 2011

## Ecological flatness of the earth (part 1)

Pretty much everyone (including me) thinks that the world is round, but very rarely is it obvious that this is the case: In our every day lives the world is for all intents and purposes flat. It strikes me as a little absurd that thinking that world is flat is taken to be so incredibly ignorant, when there is so little direct sensory evidence for it. If you haven’t gone to the sea and observed ships crossing the horizon, or performed some experiment to demonstrate it, thinking the world is round is really only taking other peoples word for it. The roundness of the earth is almost completely detached from what we experience and the fact that most of us have this knowledge is a real tribute to our ability for abstract thought.

The intangibility of the roundness of the earth is an excellent example for my ongoing campaign to make people aware of just how far our understanding of the world is from our direct experience of it. Considering the world at the level of our physical interactions with it seems to be ignored by our post-enlightenment mindset – I think it needs setting straight. And the best way of doing this is to represent familiar but abstract concepts in ways that relate to our basic interactions with the world (ecologically, to borrow J. J. Gibson‘s term)

This is my first demonstration of how unnatural thinking the world is round is: I will calculate how big a circle I need to walk in to decide with confidence that the world is round. We all have an intuitive grasp of how far it is to walk somewhere, so the question is: how affected should this understanding be by the curvature of the earth. This is based on the principle that circles are “smaller” on a sphere than they are on a flat surface, reflecting the formal definition of curvature (almost) exactly.

June 4, 2011

## The Projected Mind

This is a post about the “Projected Mind Fallacy”, as named by Edwin Jaynes. Roughly, the projected mind fallacy is the mistaking of uncertainty about the world for a property of the world itself. In other words, thinking that God plays dice. Unfortunately though, it’s not as simple as this and I feel that it’s interpretation deserves some discussion. It is not obvious exactly what should count ‘the world itself’/the non dice playing God/reality, the rest of this post is about how I think this question should be answered (and some other stuff).

Mind projection fallacies can often be spotted by their absurdity: If I had a bag of snooker balls it would be ridiculous to think that the balls exist in some kind of mixture of colours until I pick them out an look at them. Surely the balls are objectively some colour whether or not I decide to look at them. It is (if one accepts the mind projection fallacy) fallacious to say that that the balls that have an indeterminant colour, when in fact, it is just me who doesn’t know which one I will pick out. It is often stated as the confusion of ontology with epistemology, but these words don’t really help anyone understand it.

April 18, 2011

## Entropy is Disorder

Well, it’s not exactly, but I thought I’d be argumentative. Here is the problem with entropy and disorder as I see it, possibly somewhat different to Nathaniel.

There are two things that are commonly called entropy, one of which is a specific case of the other. These two types of entropy are physical/thermodynamic entropy and statistical entropy. Thermodynamic entropy is a statistical entropy applied specifically to physical microstates. As physicists generally agree on their definition of the microstates, thermodynamic entropy is well defined physical quantity. Statistical entropy on the other hand can be applied to anything that we can define a probability measure for.

April 17, 2011

## A scientist modelling a scientist modelling science

The is a follow up from Nathaniel’s post. One of the ways that the probabilities of probabilities can be used is in asking what experiments would be best for a scientist to do. We can do this because scientists would like to have a logically consistent system that describes the world but make measurements which are not completely certain – the interpretation of probability as uncertain logic is justified.

Lets make a probabilist model of scientific inquiry. To do this, the first component we need is a model of “what science knows”, or equally, “what the literature says”. For the purposes here, I will only consider what science knows about one statement: “The literature says X is true”. I’ll write this as $p(X|L)$ and its negation as $p(\bar{X}|L) = 1 - p(X|L)$. This is a really minimal example.