Saturday, May 31, 2008

The Search for Life in the Universe

Just some small thoughts on the unlikeliness of finding an extra-terrestrial civilization that is not deliberately trying to contact unknown civilizations.

If a civilization is not trying to contact others, we would have to detect their actions. Over interplanetary distances, the only thing we can detect is electromagnetic radiation (light, radio waves ...). If we could take detailed photos of a planet surface, we might see cities or other evidence of civilization. We might also detect their attempts to communicate with each other (think radio, TV, cell phones...). In both cases the frequencies we would look for are those that are not absorbed by the planet atmosphere. In all cases, detection involves the recognition of patterns in the signal that indicate intelligence. Planets are next to suns. Suns transmit huge amounts of energy that mask planetary signals. Without traveling close to the solar system, we will probably never get detailed enough information to isolate sources from a particular region of a planet. That is, we won't be able to resolve images that would show us cities.

There is a chance that something like a radio signal might be regular enough and powerful enough to be distinguished from the background, but this is likely to occur only briefly in a civilization's history. Our own experience indicates that communication feeds on itself. The tendency is to try to increase the amount of information transmitted. Over time, all bandwidth that can be used will be used and that every given bandwidth will be saturated. In our case, we have compressed signals, which reduces the direct intelligibility. We have used both time and frequency multiplexing which smears signals together. Finally, we have reduced the power for any given communication to a minimum both to increase the number of devices that can communicate and to reduce interference.

The end result is that our civilization's internal conversations, and likely any other technologically advancing civilization, will be essentially undetectable. There is an infinitesimal increase in heat at frequencies transparent to the atmosphere, but no possibility of detecting intelligible transmissions.

If a civilization inhabits multiple planets or stars, we might detect traces of those signals, but this too is extremely unlikely. Such signals have a known destination and are likely to be highly directed. That makes eavesdropping difficult. Even if we received the signal, we probably could not recognize it as such because, again, available bandwidth will probably be saturated and the signals, in effect, disguised by compression and multiplexing.

That leaves only communications from civilizations that are deliberately trying to contact unknown civilizations.

Sunday, May 18, 2008

Ugly US Money

I think United States money is the ugliest in the world. You can check out money from other countries at Compare this sample from Papua New Guinea with the new five dollar bill from the US. Honestly, can you think of anything more idiotic looking that those yellow 05s pasted randomly. Oh wait, there is the huge purple numeral five. I am sure these "features" serve a purpose. I am also sure the purpose could be served in an artistic fashion.

When the treasury department announced a redesign of US bills I had great hopes. The US public was extremely resistant to change and it was the threat/actuality of massive counterfeiting that forced redesign. Before that, it seemed that George Washington had produced the designs after 40 days on Mount Sinai.

My hopes have been dashed. As it turns out, the new designs were solely concerned with protecting the currency. Check the Bureau of Engraving and Printing at There is no indication that the engraving bureau thinks AT ALL about the appearance of the money. It is obvious that artists had little influence and no control. In other countries they realize that protection mechanisms can be implemented to create bills that are both beautiful and functional.

I highly doubt that this post will ever be seen by anyone in the Bureau of Engraving and Printing but, just in case, here is a concrete suggestion.

Currency should be designed by artists. A single artist should control the design of a single bill. It may be best if the same artist designs a whole series. The controlling artist should be aware of security and usability constraints. Security and usability people should be able to veto a design, but they should never be able to pick up a pen and modify a design.

If there are artists involved in the design of US currency, they are either not very good, or they have no real control of the design. For a case study on how currency should be designed see the lecture by Oootije Oxenaar at

At the Engraving Bureau, clearly the wrong people are doing graphic design. Even Antarctica,, gets better looking money than the United States.

Saturday, May 17, 2008

What to Learn in College

My cousin Tommy has been involved with education for a very long time and recently wrote a book collecting some of his speeches to students. Many of them deal with liberal arts education.

I too think an undergraduate education should not be vocational. When my children went off to college, I spent some time thinking about what I wished them to learn in their first higher education adventure. I came up with three broad areas.

First is something that teaches them how to think logically. I mean that literally. It is important to be able to form a syllogism. I want them to understand that "if [x] then [y]" also means "if not [y] then not [x]". It is important for everyone to be able to form a chain of inferences that either prove or disprove a proposition. This is rigorously taught in mathematics, philosophy, and perhaps even physics classes.

Second, is something that teaches how vast and complex the world is. Because of this size and complexity, it is difficult to make simple statements truthfully explain real events. Even the simplest situations tend to be more complex than we initially expect. On the african savannah, elephants and other grazing animals eat acacia. To protect the trees, fences were put up. That harmed the trees. The trees live symbiotically with ants. The trees provide nectar, the ants discourage grazing. Without the grazing, the trees produced less nectar. With less nectar, different ants moved in. The new species of ant didn't protect the trees against beetles. We can learn about complexity from biology and history classes (among others).

Third is something that teaches about beauty. In my own life the study of aesthetics has been personally important and meaningful, so I feel this is an important area of knowledge. Art, music, dance, literature ... all provide roads to understanding of beauty. I have a personal preference for the non-verbal arts.

To these three, I think I would now add a fourth. I think the study of human motivation and behavior is becoming increasingly important. I also think that this study has to be based on the other three pillars. To understand human behavior you must be able to think clearly, understand complexity, and show compassion. I cannot verbalize, but I think that art is one path to compassion.

Saturday, May 3, 2008

Averages and Actuals - Groups and Individuals

Periodically news comes out that [group X] scores lower than [group Y] on the [test of Z]. The groups and tests differ depending on who is doing the testing and where it is done. In a way it is like ethnic jokes. The group that scores higher is usually a dominant group at the time and place where the study is done. The group that scores lower is generally of some concern to the dominant group. Sometimes the work stems from real societal concern. For example: [women] score lower than [men] in [math tests]. If you are interested in math education, or sex linked traits this is a legitimate concern.

I see references to these studies in the news. Usually if follows a common news pattern:

• It is inflammatory. Everyone in the group that scores lower is bound to be insulted. The reporter can create an objective report filled with outrage on all sides "You are calling all of us stupid!" and "You are misrepresenting the work!".
• The headline and the perhaps the lead paragraph are terrible simplifications of the work and are easy to misinterpret.
• Further study and clarification show flaws in the original work or provide evidence that something unexpected is at work. These clarifications do not get the same attention as the initial headlines.
• The news is irrelevant to anyone but specialists in the field.

This particular news pattern is also present in most national crime stories (missing child, grisly murder...) and lawsuits (man sues for a gazilion dollars upon death of tropical fish).

The part that interests me today is the irrelevance of the information. To see this, let me invent a story and pretend it is true. "Women score significantly lower than men in spatial reasoning tests. Scores on spatial reasoning tests are among the best indicators of success in engineering graphics." Let me also posit that I am a manager in an engineering graphics firm that is looking for new employees. How does this information help me?

Almost any test taken by a large population shows a wide variance in skill. In most cases the results form what is called a normal distribution, the familiar bell shaped curve. This expresses the fact that there is an average level of skill and that most people's scores cluster to some degree around that average. The ends of the bell curve show that there are a some people who do extremely well (or extremely poorly) on the test.

When we hear that [group X] scores lower than [group Y] on the [test of Z], what that really means is that when we compare the curves for the two groups, the average score is lower in one group than the other. Even with a perfect test, depending on how many people take the test and who they are, we can expect some differences. Statisticians have been studying this for a few centuries and they have developed measures for how likely it is that the the differences between the averages of the test scores is just an accident of who happened to take the test or whether there may be some real underlying phenomena. Usually news that [group X] scores lower than [group Y] on the [test of Z] involves differences larger than we would expect by chance, but sometimes not by much. In our case, let's assume that women, on average, score WAY below men and that chance is extremely unlikely to be the cause of the difference.

As the hiring manager, I do not hire an average man or an average woman. I hire a specific man or a specific woman. When I am interviewing a particular person, I may be faced with a man who scores much lower than the women's average or I may be faced with a woman who scores much higher than the men's average. Here is another way to put it. Women, on average, may score lower than men. But given any particular man, regardless of how well he scores on the test, I can almost certainly find a particular woman who scores even higher.

It is hard to imagine someone more concerned with the results of testing than our hiring manager, but it turns out that our study of the difference between men and women is completely irrelevant. What matters is the particular man or woman across the desk.