Try This @home!

In the field of cryptography there is a code-breaking technique - probably never actually implemented but still of theoretical interest - known as the "Chinese Radio" method. It postulates a government such as, say, the Chinese, that has the power to insert a certain cryptographic chip in every radio produced in the country. All these chips are designed to attempt a brute-force attack on a cryptographic key. Each chip may cover a unique portion of the space of all possible keys. Or they may simply randomly try keys, which is less efficient but easier to implement. Eventually one of them will find the correct key. When this happens, a signal is transmitted back to the government.

This is of course a kind of parallel computing technology and perhaps the Chinese Radio technique was the inspiration for SETI@home, a SETI data analysis system that uses Internet-connected computers to search for that elusive monochromatic signal.

SETI@home provides any interested person with a free screensaver that employs their otherwise-idle computer resources to analyze downloaded "work units" of data from SETI receivers at the Arecibo Radio Observatory. The analysis looks for spectra containing unusual amounts of energy in a single computed increment of spectrum. If found, this would meet the definition of a monochromatic signal, and the information about the candidate signal is automatically sent to the SETI@home team. Since there are many earthbound sources of such signals that contaminate SETI data, the candidates are analyzed in order to weed out such unwanted findings. A few signal candidates have made it through this analysis, but they have not reappeared in follow-up searches.

While the screensaver is running, the computer user is entertained by a display of spectra plotted one above the other on the screen, each shifted slightly to the side, presenting what resembles an aerial view of a mountain range. Although the user may enjoy watching for signals, the actual detection would be performed automatically.

The program appears to be very well organized and we can understand the appeal that attracted a quarter million users as of August 2000.

SETI@home and the SETI program itself have succeeded in tapping the yearning that lies deep in our society - yearning to connect with something larger. SETI has succeeded in gaining the support of individuals and foundations of all sizes to help it carry on its search.

But is this search actually likely to succeed? We think, ironically, that it is not, and we so stated in the symposium paper that inaugurated Open SETI in 1994. At that time, in language still present in this essay, we showed that SETI will never be satisfied, and will always want more and more sensitive receivers and more searching, without end.64

Yet our society already is inundated - saturated - with evidence of extraterrestrial intelligence.

SETI@home Now Searching for Pulsed Signals

In SETI@home's May 2000 Newsletter, Dan Werthimer announced the development of a pulse-searching algorithm that was later released in SETI@home Version 3.0. Werthimer provided the following rationale and description of the new search:
'Much like a light house sends out regular optical flashes, another civilization might send out regular radio pulses. If we converted these radio waves into sound waves, you might hear "click, click, click...".'
...not unlike a pulsar, as a matter of fact.

Pulsar signals when reproduced by radio astronomy receivers actually do make a "click, click, click..." sound or, when they are fast, a buzz or raspy musical note. In general, that is the way pulsed signals designed for efficiency as beacons would sound. But the SETI@home pulsed-signal algorithm, having been tacked onto a receiving system designed for monochromatic signals, would be rather insensitive to that type of pulse. The SETI@home design is optimized for pulses on the order of one second in length.

If galactic societies followed the logic outlined by Cullers, Linscott, and Oliver--SETI scientists who were describing the canonical principles of orthodox SETI--SETI@home receivers and post processing systems would be pulse receivers first and monochromatic signal receivers as a distant second. (See Choosing the Target Signal Type.)

My point is not that the SETI scientists were necessarily correct in their proposition, it is that they do not even follow their own logic. I would think that SETI, calling itself a scientific program, would at least take care to be internally self-consistent.

For those readers who have seen the Open SETI page on pulsars, I am not arguing here that SETI@home or other SETI programs should be searching for pulsars. These we have already found, in great number. They reveal strong signs of intelligent control. SETI ought to be occupying itself with a systematic examination of pulsar signals.

Who can Conduct Pulsar SETI Research?

If SETI@home is appealing to the individual who wants to become a part of the great search, pulsar research should be moreso, and more appealing to scientific institutions as well, for many reasons including these:

  1. This would not be a "needle in a haystack" search; it would be an analysis of data already suggestive of ETI origin.
  2. Although special data collection may eventually be employed, no data collection program need be undertaken at first and for some time to come. Ample data have already been collected.
  3. The cost of this activity is very low. The only investment needed at this time is in the intellectual resources required to search for signficant patterns.
  4. Much groundwork has already been performed by the researcher Paul LaViolette. Thus the next step is simply to check the validity of his findings.

Is there a way for readers of this essay to become involved in a SETI project that has REAL and PALPABLE prospects for epoch-making success? Before attempting an answer to that I would like to stop here and list the types of people I think are reading this. They might be categorized as follows:

  1. Individuals who have no training or background in astronomy, or even in any of the sciences that demand an orderly approach to numerical data, but who have an interest in the topics discussed throughout this essay, and who may be using the SETI@home screensaver. For these individuals I have to say that my own preliminary survey of the field of pulsar research indicates that pulsar data resources are not sufficiently accessible to be of much use. I would suggest that such individuals recognize that other possibilities for research or simply reading are very rich and that they pursue their choice of many excellent lines of study.
  2. Amateur astronomers, amateur radio operators, radio communication engineers, cryptographers, and others who have studied the radio sciences or have some background in a hard science, engineering, or mathematical discipline. In fact, there is a community of "amateur radio astronomers" devoted to the use of home-built systems designed to acquire and study signals from pulsars and other celestial objects. (Visit the Radio-Sky Publishing site for information, resources, and discussions supporting amateur radio astronomy projects.) These individuals might find it rewarding to access publicly-available pulsar data recordings. As stated, they might begin their work by verifying some of the findings of Paul LaViolette (2000), and by extending what has now been discovered about the patterns in the individual pulses, grammatical switching rules, global behavior, etc. To assist interested experimenters, I will momentarily present some links to possible data resources.
  3. Professional astronomers, radio astronomers, astrophysicists, especially with university affiliations. These individuals would appear to have greater possibilities for developing research programs with possible grant support, etc. However, most of them would probably agree there is little chance of finding funding for pulsar SETI research, at least from the foundations that normally fund radio astronomy. And spending time on grant proposals for this research would not make them very popular in their departments. That is the situation we face: perfectly good instrumentation cannot be put to this use. But of course I would encourage them to try, and to be sure to publish their findings!
  4. Long-standing members of the SETI community. For these individuals, this Open SETI website is a postcard.

Beginning your Personal Pulsar Research Program

If you would like to conduct your own studies of pulsar signals your first step should be to familiarize yourself with the literature on pulsars--or at least that subset of the pulsar literature that would be of most interest in connection with the "pulsars as ET beacons" idea. The Talk of the Galaxy provides a valuable bibliography and list of references.

Naturally you are going to need some data. While experimenters will immediately think of building a small radiotelescope and receiver, this would probably not be a fruitful approach. You are going to need individual pulse sequences and therefore will not be able to perform signal averaging. Capturing sufficient energy from single pulses requires the signal gathering capability of one of the great radiotelescopes. Therefore you should consider obtaining and using data already recorded, published, and available.

Begin by building a catalog or database containing the gross characteristics of the set of observed pulsars. From a study of this database you may then determine which pulsars merit closer examination.

A suitable catalog of 706 pulsars is available as a tar file (a UNIX archive format) from the Princeton ftp site After downloading, the file can be expanded on a UNIX or other system. The package contains source for FORTRAN routines that provide access to detailed pulsar information as well as summaries. Alternatively, it would not be difficult to generate shell scripts to format data reports, to input the catalog into any of a variety of databases, or to employ utilities of your choice available at little or no cost for UNIX or other systems.

The European Pulsar Network (EPN) Data Archive provides time-averaged pulse profile data from thirty-six (at the time of writing) research papers.

Use such catalogs as you find or can build to search for global distributions of characteristics that might be surprising in terms of the conventional neutron star lighthouse pulsar models. Perform statistical tests or whatever is needed to uncover and highlight any anomalies.

You then may wish to focus on the specific pulsars that are associated with or that make up those anomalies. This is where you will need the individual sequences. When I learn more about where these can be found I will publish that information on this page.

Here are some additional resources:


Caltech Computational Astronomy

US Naval Research Laboratory

Princeton Pulsar Group: Publication Archives


Princeton Pulsar Group: Pulsar Catalog

Princeton Pulsar Map Applet

Call for Founding Members of the Open SETI Pulsar Research Group

Paul LaViolette has generously made available 27 MB of high-resolution pulse recordings from the Vela pulsar. The signals included in this set of data presumably exhibit some of the anomalous features that were described in his book The Talk of the Galaxy, and on the Pulsars page, this website. The presence of anomalous pulse features needs to be confirmed and, once confirmed, be studied more deeply and creatively in a search for intentionally-created patterns and meaning among the anomalies.

A proposed rigorous multi-disciplinary research program is outlined in Invitation to a Collaborative Study. If you feel you have skills that would be useful in this effort, you are welcome to contact me directly with an introduction and informal proposal.

Open SETI Pulsars More Challenges to the Old Paradigm