Searching for Extraterrestrial Intelligence in Space and Time

Voyager 1 - Image credit: NASA/JPL-Caltech

It's estimated that there are about 30 billion trillion stars in the Universe. Recent scientific discoveries suggest that many of those stars may have planets. Indeed, current evidence suggests that there may be billions of planets similar to our Earth in their ability to support life. Is it therefore likely that we, the human inhabitants of Earth, will someday discover or make contact with extraterrestrial intelligence (ETI)? Perhaps. But in considering that question, we have to take into account the magnitude of both time and space.

Scientists currently believe the age of our Universe to be about 13.8 billions years old. Our Sun is thought to be about 5 billion years old. There's evidence that simple-celled life first appeared on earth about 3.6 billion years ago. Fossil remains suggest that homo habilis emerged about 2.5 million years ago, and homo sapiens has been around perhaps 200,000 years -- though estimates vary, as do theories about when modern human behavior emerged.

To give you an idea of how short human existence has been, if we consider the age of the Universe to be one year that began on January 1, then our sun would have appeared around August 20 and our earth around September 3.  Life in the form of simple cells would have been present near the end of September, and animals in the middle of December. Mammals would have come around December 26 and primates around December 30. The first hominids would have shown up around noon on December 31, and the first members of the genus homo would have arrived around 10:30pm. Homo sapiens would have appeared anatomically sometime sometime during the last 10 minutes of the year, begun to exhibit modern behavior perhaps in the last 2-3 minutes, and invented writing sometime during the last 15 seconds. Within this metaphorical cosmic year, the time of homo sapiens will that of one dance if we survive and thrive for another 50,000 years, and that of a thunderstorm if we last another 500,000.

Biological processes tend to be self-limiting. On earth, species have come and gone. If this is our fate and the fate of all intelligent life in the Universe, the chances of encounter depend greatly on how long it takes intelligent life to develop and how long it can survive. Let us suppose there are 100 trillion planets that will, at some point in their existence, have intelligent life capable of reaching out. If that were to happen at random for the period of one dance during my metaphorical cosmic year, we would have several hundred thousand potential partners. If the time of reaching out is more like the metaphorical thunderstorm, the number of potential partners increases to over half a billion. This may seem like good odds, but we also must take into account the vastness of space.

Consider the distance between galaxies. The Andromeda galaxy, a near neighbor of our own Milky Way, is about 163,000 light years away. If an observer within Andromeda were to have a telescope powerful enough to see the surface of the earth in detail, looking today they would be seeing the earth as it was ~163,000 years ago. Thus, they might see hominids (including Neanderthals) making tools of bone and stone, living in shelters, wearing clothing and controlling fire. That observer might conclude that there was intelligent life on earth, and might also decide to attempt communication in hope that by the time the signal arrived, the intended recipients would have the technology to detect it. In 163,000 years or so from today, that signal would arrive.

Given the time-distance involved, unless we learn how to communicate faster than the speed of light, it seems unlikely that we'll be exchanging signals any time soon with intelligent life outside our own galaxy. However, within our own Milky Way, which spans at least 100,000 light years in its longest direction, the Kepler space telescope has found over 1700 planets that are within 3,000 light years from earth. That's just since 2009, and our ability to find planets has recently gotten better. We now have reason to believe that there are many planets out there orbiting stars whose distance in light years is comparable to the 5,000 or so years since the earliest known evidence of writing.

Now, as a hypothetical exercise, let's suppose that the ~600 million stars within that distance have an average of one planet each that's in the habitable zone, and that complex life develops on 10% of those. If intelligent life is but a dance occurring randomly within the cosmic year, we would have 100 or so potential partners. If it's a thunderstorm, that number expands to over 3,000. If, on the other hand, it takes about the same amount of time for intelligent life to emerge on each planet, our chances of detecting it would be much greater. In addition, there's the chance of finding evidence of an intelligent civilization that once was and is no more.

Even so, what these back-of-the-envelope calculations suggest to me is that the search for ETI is an act of optimism, grounded in the hope that intelligence confers the ability to plant a continuing harvest for posterity rather depleting the soil or sowing the seeds of its own destruction.

A Small Neighborhood in Fornax

My last post was about an image I created using FITS data I got from SkyView. Here's an image from NASA showing a larger view of the same region in space. This is a small area in the celestial sphere, spanning only one minute of arc. It's located in the constellation Fornax, which occupies an area of 398 square degrees. The name Fornax comes from the French astronomer Nicolas Louis de Lacaille, who first formed this constellation and called it Fornax Chimiae ("chemical furnace").

The constellation Fornax can be seen from the southern sky, but the stars and galaxies shown in the image above cannot be seen with the naked eye. They are in what's known as a "dark field," a region where there is not much background radiation. By surveying such regions with the Hubble Space Telescope, astronomers are able to detect and study faint galaxies in the early universe to learn more about how galaxies evolve.

FITS Liberator Image from 03h32m29.3s, -27d44m10.0s (J2000)

This is an image I created today using the FITS Liberator with data obtained from SkyView. What you're seeing is an area of deep space that was surveyed by the Hubble Space Telescope Advanced Camera for Surveys (HST ACS). I got the FITS data by giving SkyView the coordinates 03h32m29.3s, -27d44m10.0s (J2000 co-ordinate system) and specifying regions .02 degrees in size.

To get a color image, I downloaded three sets of FITS data, each covering the same area of space, but with different filters for wavelength. Using the FITS Liberator, I converted each data set into a TIFF image. I then loaded the TIFF images in to Adobe Photoshop to make a stack of three layers and gave a different color (i.e. red, green, blue) to each layer. After making some curves adjustments, I got the image you see above.

Making this image involved a series of subjective judgements, first in managing the dynamic ranges of images with the FITS Liberator, and then in tweaking curves in Photoshop. So the image you see should be considered an artistic rendering of astronomical data rather than a "snapshot" of outer space. I did, however, try to keep the colors basically "natural" by assigning blue to the shortest frequency filter, red to the highest frequency, and green to the one in the middle.

When looking at my image, you may be wondering if there's a way to describe the part of space it shows other than by the coordinates I've provided. I was wondering that too, at first!  I've never taken a class in astronomy, and I understand less than half of what I read on the subject. However, I'm fascinated by astrophotography. So my approach to learning about astronomy has been to find interesting images and then try to understand what they show. If you're an astronomy buff, you may know what my image shows. Otherwise, you're going to have to wait for me to post more information.

The Asymmetric Internet

As the Internet was opened to commercial use in the 1990s, access became available to people outside of academic and research organizations. Various companies -- large and small, local and national -- began to offer dial-up access to the Internet for people who wanted to exchange information by such methods as email, newsgroups, file sharing and online chat. This information sharing typically involved a mix of "upstream" and "downstream" data transfer between users and ISPs. For example, when user A sent user B an email message, information went upstream to A's ISP (X), across the Internet to B's ISP (Y), and then downstream to B. When user B sent an email reply, information was sent in the opposite direction.

The dial-up connections that people used to share information across the Internet in this way were symmetric, in that they were able to transmit data between the user and their ISP both upstream and downstream with equal facility. The same was true for the higher-speed telecom connections between IPSs. In the early days of the Internet, these symmetric connections were intended to facilitate long-distance collaborations in which the various participants all had information and ideas to share.

As the Internet grew and evolved, people began to feel constrained by the data transfer speeds of dial-up connections. As DSL and cable connections became available, they were rapidly adopted by those seeking greater bandwidth. These new technologies were deployed, in most cases, to provide higher data rates downstream than upstream, making them different from the telecom connections that had previously been used for Internet connections.

Today we have an Internet over which a small number of "content providers" send large amounts of data downstream to end users. Is this a natural evolution to which technology has adapted, or has the technology itself produced this result?

I understand that certain kinds of content are easier to consume than to produce, leading to a natural asymmetry in the proportion of writers to readers, performers to audience, etc. However, the skills and talents required to produce good content are, I believe, distributed around the globe. Furthermore, the kind of data that can be carried by the Internet can be used for many purposes. So my questions are these: If we had an Internet that gave us all a high-speed connection both upstream and downstream, would the way we use the Internet change? Would the Internet be used for two-way communication and collaboration more than it is today? Would more good writing, good photography, good music, good video, good ideas be available to us? Would innovators be stimulated to create new technologies and new applications?

Why do we have an asymmetric Internet? Is what we get based on what we want, or is what we seem to want based on what we get?

From Citizen to Consumer

The chart above, which I produced using the Google Ngram Viewer, shows how use of the term "citizen" has declined, while use of the term "consumer" has increased.

In the context of discussions about public policy, I prefer being referred to as a "citizen" rather than a "consumer." To me, the word "citizen" connotes an agent who acts and makes decisions within a matrix of rights, responsibilities and ethical values that's greater in scope than the economic decision matrix implied by the word "consumer." This is not to claim that people make consumer choices based on economic calculus alone, but rather to suggest that deviations from this calculus tend to be seen as just that -- deviations -- when the agents making choices are thought of as "consumers" rather than as "citizens."

However, the nuanced meaning of words and the cloud of associations they evoke change over time. In her book A Consumer's Republic: The Politics of Mass Consumption in Postwar America, Lizbeth Cohen discusses how the identification of American citizens as "consumers" shifted during the 20th century from a grounding in ideas of civic responsibility and democratic values to an insular emphasis on personal benefit. Such shifts in meaning can not only reflect change but also create it, as words have the ability to shape perceptions. (Cohen also has written a short article summarizing the main points of her book.)

In their book Citizens or Consumers? What the Media Tell Us about Political Participation, Justin Lewis, Sanna Inthorn and Karin Walh-Jorgenson describe the results of their research based on empirical data from 5,658 news stories that were published in Britain and in the United States. Stuart Allen, series editor, describes the book as follows:

"This book enters squarely into the current controversy about the declining number of people engaged in the conventional political process. Based on the first comprehensive study of the way citizens are represented in the news, it provides powerful evidence that while the news media may not be responsible for this decline, they are doing little to help remedy it. Although many people do have clear ideas about politics and matters of public policy, the authors argue, the news media are much more likely to present citizens as passive, incoherent or or disengaged. Their research into news reporting suggests that the idea of the citizen has been more or less eclipsed by the figure of the consumer. So while we hear a great deal about the 'consumer confidence' on which economies depend, we hear very little about the 'citizen confidence' on which democracies depend."

Perhaps it's time to reverse the trend and bring the word "citizen" back into our daily discourse.

Orion Nebula

Photo Credit:  Jim de Lillo and the ESA/ESO/NASA FITS Liberator

Jim de Lillo created this stunning image of the Orion Nebula from three 120-second exposures he took using the Lightbucks Remote Telescope Network LB-0004 in Pingelly, Australia.

The Pink Planet

Artist's conception of GJ 504b
Image Credit: NASA's Goddard Space Flight Center/S. Wiessinger

Planets are hard to "see" because they orbit around stars that are much bigger and brighter. For this reason, most of the planets we know of outside our own solar system have been detected and studied using measurements and mathematics.

In recent years, though, it's become increasingly possible to detect certain kinds of planets from the direct observations of scientific telescopes, which can use filters to capture infrared radiation and turn it into visible images.

The planet GJ 504b, dubbed the "pink planet" was recently imaged in this way using infrared observations from the Subaru Telescope on Mauna Kea in Hawaii. Most of the planets observed so far by direct imaging have been large and relatively far away from the sun they orbit. The pink planet fits that description, but it currently holds the record for being the least massive planet observed in this way. Even so, it's a large planet like Jupiter.  It's that similarity to Jupiter together with its distance from its sun that makes GJ 504b interesting to astronomers.

If planets like Jupiter form within the gas disc of a young star, as many astronomers have believed, then you'd expect to find such planets no farther away from their sun that the planet Neptune is from our sun -- a distance of 30 AU (astronomical units). Contrary to this prediction, GJ 504b is estimated to be 43.5 AU from its sun. That's difficult to explain with any of the current theories about how planets are formed.

What's easier to explain is why GJ 504b is pink. It's part of a relatively new solar system that was formed only ~160 million years ago, making it 30 times younger than our earth, so the planet is still cooling down. It's lost some of its heat, making it cooler than other planets that have been directly imaged, but it's still hot enough to have a magenta glow.