Friday, December 28, 2007

The Margolus-Levitin Theorem, the Beckenstein Bound, and Computronium

Computronium is a proposed form of matter that is optimized for computation. The speed of the fastest possible computer can be calculated by the Margolus-Levitin theorem, which states that that rate is (E * 4) / h, where E is the amount of energy available to the system in joules (the maximum value is E = mc^2, where m is mass in kilograms and c is the speed of light, 3 *10^8 m/s) and h is Planck's constant, which is approximately 6.626 * 10^-34 J * s. The units of the result are operations per second. The maximum possible memory capacity of a computer is related to the Beckenstein bound, which is the maximum amount of information that a given region of space can contain. This equals one bit per 4 square Planck lengths (a Planck length is approximately 1.616 * 10^-35 meters. This means that one kilogram of computronium taking up a volume of one liter could perform 10^51 operations per second and store 10^31 bits. For comparison, the world's fastest computer can currently perform 10^15 operations per second and a typical large hard drive can store one terabyte (approximately 10^13 bits). Processing speeds and memory capacities are currently doubling about every 12 and 15 months, respectively. If these trends continue, the maximum possible storage density will be reached around the year 2080 and the fastest possible computing speed will be reached around 2200. The Margolus-Levitin theorem also implies that computation speed is inversly proportional to entropy. On a tangentially related note, there is an interesting post on the generally obstructive effect of disorder on intelligent processes at Tom McCabe's blog.

Tuesday, December 25, 2007

Happy Holidays

For over a century humanity has searched the skies for signs of other intelligent civilizations. In fact, Nikola Tesla designed an early radio for specifically this purpose. That search has found nothing but a black silence spanning 13.7 billion lights years in every direction. No other known place in this inconceivably huge expanse is there creatures that we can call friends. I hope that everyone, myself included, keeps this fact in mind as we interact with others. Life and mind seem to be vanishingly scarce resources. May we be grateful for every day that we experience them.

Wednesday, December 5, 2007

A Summary of Social Biases

Here's a non-exhaustive list of social biases and some thoughts on how they interact.

Biases related to self estimation

egocentric bias- The tendency to give ourselves more credit for positive outcomes than a neutral observer would when engaging in an activity with others.

self-serving bias- Then tendency to credit ourselves for successes and attribute failures to outside causes, or in other words, having an external locus of control. This is often combined with egocentric bias.

over-confidence bias- The tendency to over-estimate our own competence. More specifically, the Dunning-Kruger effect is when someone believes that they are making valid choices even after experiencing negative outcomes. For reasons I can't easily comprehend Dunning and Kruger won a 2000 Ig Noble for a paper they published on this topic, especially in light of the fact that winners that year included a comparative study of the tastiness of Costa Rican tad poles.

illusion of control- The tendency for individuals to believe that they can control events which are in fact beyond their control.

Group biases

Reactance- The tendency to do the opposite of what one is instructed to do by others because of the perception that they are trying to restrict one's freedom. Clever marketers have created an industry tailored to non-conformist teenagers by exploiting this bias i.e. "the rebel sell".

deformation professionnelle- the tendency to examine issues from the viewpoint of one's profession only and neglect other perspectives.

bandwagon effect- the tendency to hold beliefs simply because they are popular.

notional bias- the belief that the views of one's culture are natural law.

status quo bias- the tendency to favor certain circumstances simply because they are familiar.

system justification- defending current circumstances to the point of being detrimental to one's own interests. This can act in tandem with status quo bias and the bandwagon effect.

ingroup bias- the tendency to behave more favorably to people who are perceived to be members of one's own group.

stereotyping- the tendency to attribute traits to someone simply because they are a member of a certain group.

outgroup homogeneity bias- The belief that the members of one's own group are more varied than members of other groups. "All [insert ethnic group that the speaker is not a member of here] look alike." Stereotyping, ingroup bias, and outgroup homogeneity bias are contributing factors in racist beliefs.

Social interaction biases

halo effect- the tendency to believe that people are generally good or bad because of one observed superficial positive or negative trait. The great importance assigned to first impressions is a result of this bias.

false consensus effect- the belief that others agree with us more than they actually do.

illusion of asymetric insight- the belief that we know others better than they know us.

illusion of transparency- the tendency to over-estimate the ability of others to know us. This results in blaming mis-communications on others rather than believing that we were not clear. This is one that I definitely need to work on.

projection bias- the assumption that other's share our beliefs. This can act in tandem with the illusion of transparency and the false consensus effect.

trait ascription bias- the tendency to believe that we are more unpredictable than others.

actor-observer bias- the tendency to attribute our own actions to our situation and the actions of others to their personalities. This is a particularly nasty one in my opinion. It can cause serious distortions of our moral judgments.

It seems that a recurring theme in social interaction biases is that we tend to believe that we have a richer internal thought life than others. Keeping this error in mind can not only help us behave more rationally, but also help us to be more friendly.