Category Archive

This past Wednesday Col Maybury, host of the Australian radio show The Starlight Zone, interviewed Shawn and I about covering the far side of the Moon with mirrors as a remotely detectable technosignature.

Listen to the complete (~5 minute) interview at the Starlight Zone

This idea got far more press than either of us had anticipated, so we tried to use our air time to do some damage control and clarify the idea beyond the scope of a brief news write-up. We are currently in the process of drafting the manuscript for submission.

This work is unfunded: We came up with this idea following the Pale Blue Dot III meeting as a solution to particular problems with the SETI approach to finding intelligence; however, we are not funded to develop this idea nor do we have any intentions of proposing construction of mirrors on the Moon to any funding agency. (Our global society can’t even agree upon a consistent program to address climate change issues–I seriously doubt our ability to maintain a long-term signaling project.)

Our signal is omnidirectional: A targeted broadcast such as a radio signal or laser pulse is limited because of its directionality. Our scheme, though, covers the far side of the Moon with mirrors on pivots (with dark solar panels on the opposite side) so that the albedo of the Moon can be effectively changed from 0 to 1, resulting in a 20% change in luminosity for the Earth-Moon system. This change in luminosity will be observable from almost any direction at any time and will not require a targeted broadcast.

Our signal is broadband: Because the light reflected from the Moon’s mirrors comes from the Sun, the detected change in luminosity will span a large section of the electromagnetic spectrum (depending on the particular mirrors used). This further increases our chance of success because we make fewer assumptions about the preferred observational/communicative frequency of extraterrestrials (whereas conventional SETI presumes radio beacons or other narrow-band broadcasts).

This beacon requires current and near-future technology: The mirror/solar panel pivots can be constructed with current technology. Furthermore, we are detecting new extrasolar planets every day. In 2009, Kepler will launch in search of terrestrial planets around other stars, and in the next 10-20 years the Terrestrial Planet Finder will be able to observe these planets and take spectra of their atmospheres. In other words, within the century it will be within our technological grasp not only to build such a signal but also to detect a similar signal around a distant world.

ET’s may use a similar technique: Even if we never construct a technosignature using the Moon, it is conceivable that a technological extraterrestrial society may signal their presence using a similar method. If the Terrestrial Planet Finder were to detect an Earth-sized planet around another star blinking in the prime numbers, we would at least have a hypothesis to explain this seemingly deliberate signal.

Language is a construct, and because of this it is ultimately limited in its ability to express all ideas. Some ideas are well characterized linguistically, but this is not true of all ideas–in fact, many ideas and concepts cannot even be reasonably translated between languages! As a corollary to this, any derivative of a language system (such as logical manipulation of language symbols) is also a construct. Thus, if we limit our view of the world to only that which can be known through language (or logic, or mathematics) we risk minimizing our exposure to ideas that can only be expressed otherwise.

Fortunately, this type of worldview is almost impossible to maintain, at least for someone with even minimal exposure to the arts. In addition to music, visual art, and dance, poetry (including lyrics) provides an intermediary between the world of language and art. Poetic expression uses the same lexicon as spoken language, but the devices of metaphor and (somewhat) free reign on syntax and form create an art of language, in a sense. Powerful ideas captured in poetics have the ability to transcend the literality of words and convey an untranslatable message.

Musical and theatrical performances, then, strive to achieve this super-linguistic degree of communication (with varying degrees of success). But I think it is important to realize that a wordless song or dance can convey an idea just as real, true, and applicable as a book or speech. Ideas come from people, not from words.

David’s recent musings at The Edge of Grace got me thinking about the way we transmit and share information and experiences–as well as mystery. Language is a vehicle for communicating many ideas, ultimately language breaks down in its ability to share the experience of mystery.

This limitation of linguistic communication made me realize the importance of alternate communication modes, namely through various art forms. When I play music with others, there is a deep level of communication that is maintained through the sounds even though no words are spoken. The communication that develops over time among musical friends is without parallel in linguistics and cannot be sufficiently described in prose. Yet I am confident that any practitioner of an art form also finds expression and mystery that cannot translate into words.

And speaking of music, Cootie Brown albums are now available online! They are available directly from the Ekora webstore as well as on CD Baby.

My essay I wrote for the Pale Blue Dot III workshop was published in the August issue of the journal Astrobiology. The paper discusses the conflict that often occurs between the belief in intelligent design or creationism with the theory of evolution, particularly because the underlying story for describing both of these perspectives is sometimes similar.

View a PDF of the complete article.

For some reason, my friend Seth Schwartzhoff Boyd and I came up with this in middle school.

The perfect response to the question: Are you hungry?

Oh, I’m Chad. Why don’t you Russia on over to visit U.S. sometime. We’ll go in the Palestine, sit on the Afghanistan, and have Turkey dipped in Greece served on our best China, followed by a big Bolivia of Chile and Tunisia on the Sandwich Islands; but make sure you wash your Honduras before you eat or you’ll have Germanies all over them.

Why is it that many (most?) people prefer to categorize themselves whenever possible? Categories are a useful construct for discussion, but given the emphasis our culture places on individuality, it is interesting how often people apply a broad category in their own description. These may be ideologies (republican, democrat, libertarian, anarchist), philosophies (nihilist, materialist, Hindu, Christian), or qualities (race, gender, nationality)–nearly everyone (at least in our culture) puts themselves in such categories.

There is a language benefit in referring to a population by a category, but often an individual will cling to the identity of a category. Is it really useful to have a binary construct of politics (republican or democrat only), gender (masculine or feminine only), or religion (theist or athiest only)? When such binaries are constructed, most of us tend to fall somewhere on a spectrum between the two (sometimes arbitrary) opposites; yet we find a need to identify with a single side than to exist along the spectrum.

Perhaps categories create and enhance a sense of community, but they might also act to impede creativity.

Sometimes it’s nice to remove yourself from all (or most) forms of communication entirely and simply focus on being. We often do this by retreating into the wilderness, but can also be as simple as pulling the plug.

And speaking of inaccessible wilderness, I’m looking forward to Locust Grove in just three weeks!

Below, I have categorized several (but not all) forms of communication based on four properties:

Simultaneity (boolean) - Does the mode of communication require simultaneous participation by all parties?

Location Dependent (boolean) - Does the method of communication require being in a specific location?

Logging (boolean) - Does the method of communication typically include archival features?

Preparation (time) - How much time can reasonably be spent crafting, revising, and modifying a response?

Face to Face communication shares the same benefits and limitations as a Land Line on this chart (aside from logging), since I did not include physical distance as a factor. Snail Mail and Email both have the benefit of thoughtfulness; that is, you can spend time composing a letter or email, with the opportunity to analyze your writing and rework ideas. Instant messaging provides this benefit as well, although the active participation of both parties in Instant Messaging places a modest upper limit on composition time. The mobile phone, by definition, is the most portable of these communication modes–although there are an increasing number of portable email and Instant Messaging devices (often embedded with phones).

Any mode of communication with a true value of simultaneity will be interrupted if a similar form of communication is attempted at the same time. For example, Face to Face conversation is interrupted when a participant elects to answer their Mobile Phone. If, on the other hand, the participant received an email (or a voice message), they can ignore it until the Face to Face communication is complete.

In general, I like my available communication modes to change with my physical location, so unless I’m travelling I use my Mobile Phone as if it were a Land Line. But many people disagree, preferring communicative homogeny independent of location.

Why is xor not part of everyday speech? It would make certain situations much less ambiguous:

A) Would you like cream or sugar?
B) Would you like soup or salad?

In case A, it is generally acceptable to take cream, sugar, or both cream and sugar. In case B, though, the chose is exclusionary between soup and salad. But with xor in the lexicon, we can remove the degeneracy:

A’) Would you like cream or sugar? (inclusive or)
B’) Would you like soup xor salad? (exclusive or)

See how much easier this would be?

There are various causes and beliefs that people try to sway others to accept. Often this can take the form of a simple conversation between friends: a political discussion, a religious debate, a socio-economic comparison, or a countless number of other issues. Often the goal of such an endeavor is to change a person’s mind–not a simple feat, but something that does occasionally happen.

One method used in changing minds is evangelism. The classic example of evangelism is the big-tent-revival characterizing certain religious movements, but evangelism is used in many secular arenas as well (political campaign rallies, for example). A problem with evangelism, however, is that it gives the false impression that it is easy to change minds. Using religious evangelism as an example, consider the “call to salvation” that occurs at the end of a powerful sermon. Many people many step forward to embrace a new religious ideology, to change their former style of life. This is often cited as an example of rapid conversion; namely, the people only need to hear a message with an open mind in order to accept it.

Evangelism would be incredibly powerful if this were true, but a person’s life journey plays a much larger role in determining their acceptance of an idea. The drug addict who turns to Jesus is not making an immediate rejection of their former lifestyle in favor of a new faith. Rather, their experiences up to this point have led to an undesirable result, and the evangelical message reached them at a proper moment. AFter all, addicts can certainly be aware of their addiction (or at least the consequences), even if they take no action to change the situation. And, of course, not all converts had a large obstacle to overcome: some of these new converts have simply been on a personal philosophical journey that led to acceptance of the evangelist’s message.

Leaving the religious example, the concern over global climate change is another issue that requires a change in worldview. Evangelism to raise concern over our culture’s impact on the climate system is useful, but it is useful in the sense that it reaches out to people who are at the point where they are ready to accept this paradigm shift. These people are not making a 180-degree shift in worldview, but their journey in life has led them to the point where this message makes sense.

How are minds effectively changed, then? Evangelism should not be completely abandoned, but perhaps the one-on-one coffee shop conversations are more effective–not only because the message can be tailored to the individual, but also because these conversations contain an important personal element that is lost when addressing a crowd.

I just received a $5 bill with a red “Track this bill at www.wheresgeorge.com” stamp on it. There have been a few other times I have encountered such a bill, but this time my curiosity was stronger (and I was already sitting in front of an open web browser), so I surfed over to the site and entered my bill’s serial number. I was a little disappointed to see that there was only one other entry for this bill, from Wattsburg, VA. So my bill has travelled “134 Miles in 1 Yr, 104 Days, 19 Hrs, 16 Mins at an average of 0.29 Miles per day” according to Where’s George.

I registered for a free account, so I’ll get to see where this bill eventually travels; and I may enter a few more bills sometime. But I did find it interesting to look at the bills with the most activity. Here’s the most frequently recorded bill in the database, a 1999 series $1 bill:

You may think that lecturers/preachers just like the sound of their own voice (which may very well be true), but you may not realize that they are also efficiency experts. When a single person is the only one talking to a group, everyone is fully participating by listening. Since people are not interacting in this lecture-style, it has a complexity of O(1).

Conversations between two people are also efficient. As one person is talking, the other person is listening and formulating a response. When the second person begins talking, the roles reverse and the original speaker now becomes the listener. At any given time there is exactly one talker and one listener (at least in polite conversation), also a complexity of O(1).

The efficiency breaks down with a large group. Consider a conversation taking place between N people. As one person talks, (N-1) people are listening and formulating responses. Because only one person may speak at a time, when the second person begins speaking, there are now (N-2) + (N-1) responses being formulated. After N people have spoken, there will be 0 + 1 + 2 + … + (N-1) = N*(N-1)/2 responses formulated. Thus, while lectures and one-on-one conversations are highly efficient, group communication is highly complex with O(N²).

I think this explains a lot.

One thing I have learned this semester is the importance in recognizing the time and place for value judgements. Now, this is not a PC attempt to make everyone happy and not offend. But in a scientific context, it is important when communicating intentions and results to keep objectives seperate from interpretation and application. As a simple example, consider the difference between “the weather will improve” and “the rain will clear up”. For picnicers, less rain may be good, but it is not necessarily an improvement for the parched fields of a farmer. Non-trivially, it is crucial in the climate change discussion to make distinctions between the “anthropogenic contribution” and other phrases that might attempt to place blame or absolve responsibility. Humans have had a measurable impact on the climate system, here with regards to the carbon cycle. However, adding a value judgement muddles the science and only serves to keep the discussion away from the actual facts.

This applies beyond climate change discussion, and is important in all aspects of science. And, of course, it goes far beyond science. It makes me wonder what the world would be like if leaders and policy makers choose their words carefully between the objective and the subjective. We might have amazing results! Either that, or else we might just have vacant leadership positions.