I'm very happy to send greetings to Stuart Kingsley, my old friend Barney Oliver, and all those attending the Conference on the Optical Search for ET. At the saiae time, I'd like to tell you about an uncomfortable analogy that has just popped into my mind. ... Imagine a group of serious thinkers on a remote Pacific island who've never had any contact with the rest of the human race. Their technology is Late Neolithic, but they are philosophically inclined, and they're debating the question is there anyone else out there over the horizon? Unfortunately they can't go and look: a barrier reef right round the island discourages boat-building...

NASA began in 1989 a project to search for microwave radio evidence of technological civilizations in space. The project, designated HRMS for High Resolution Microwave Survey, is designed to search the 1 to 10 GHz microwave window for narrow band signals that could be positively identified as being transmitted by a civilization of extraterrestrial origin. The project will use existing ground-based radio observatories throughout the world for the task. Two complementary strategies will be applied in the conduct of the search: the Targeted Search and the Sky Survey. The Targeted Search will observe about 800 Sol-like stars using the largest and most sensitive antennas available while the Sky Survey will scan the entire celestial sphere by continuously moving the smaller, more flexible antennas of the NASA Deep Space Network. This paper will discuss the overall requirements and concepts of project HRMS, focusing on the Targeted Search.

The NASA High Resolution Microwave Survey consists of two complementary elements: a Sky Survey of the entire sky to a moderate level of sensitivity; and a Targeted Search of nearby stars, one at a time, to a much deeper level of sensitivity. In this paper we present a strategy for target selection and observing. The strategy has two goals: to improve the chances of successful detection of signals from technical civilizations that inhabit planets around solar- type stars, and to minimize the chances of missing signals from unexpected sites. For the main Targeted Search survey of approximately 1000 nearby solar-type stars, we argue that the selection criteria should be heavily biased by what we know about the origin and evolution of life here on earth. We propose that observations of stars with stellar companions orbiting near the habitable zone should be de-emphasized, because such companions would prevent the formation of habitable planets. We also propose that observations of stars younger than about three billion years should be de-emphasized in favor of older stars, because our own technical civilization took longer than three billion years to evolve here on earth.

I outline the three basic reasons for believing that we are alone in the Galaxy, and possibly alone in the visible universe. I argue that the experimental evidence for our uniqueness as intelligent beings is sufficiently great to make SETI a waste of time and money.

A decisive and lethal response to a naive radical skepticism concerning the prospects for the existence of Extraterrestrial Intelligence is derivable from core areas of Modern Analytic Philosophy. The naive skeptical view is fundamentally flawed in the way it oversimplifies certain complex issues, failing as it does, to recognize a special class of conceptual problems for what they really are and mistakenly treating them instead as empirical issues. Specifically, this skepticism is based upon an untenable oversimplifying mode of the 'mind-brain' relation. Moreover, independent logical considerations concerning the mind-brain relation provide evidential grounds for why we should in fact expect a priori that an Alien Intelligence will face constraints upon, and immense difficulties in, making its existence known by non- electromagnetic means.

There is a widespread and perhaps uncritically accepted assumption on the part of SETI researchers and popularizers that we could tell what an ETI might be trying to tell us. We raise difficulties for this assumption. If the assumption is abandoned, a lot follows. We might even be able to argue, in a novel way, that SETI will be utterly futile.

There is little doubt that confirmation of the existence of extraterrestrial intelligent life will be obtained from electromagnetic waves generated by our counterparts. The best frequency regions in which to expect such signals depends upon the free-space loss, the background noise, the spectral purity obtainable, and the power required as a function of frequency. This paper will discuss the rationale that led to the selection of the microwave window for the NASA SETI Program.

This paper strongly suggests that the microwave rationale behind modern-day SETI lore is suspect, and that our search for electromagnetic signals from extraterrestrial technical civilizations may be doomed to failure because we are 'tuned to the wrong frequencies'. The old idea that lasers would be better for interstellar communications is revisited. That optical transmissions might be superior for CETI/SETI has generally been discounted by the community. Indeed, there is very little in the literature about the optical approach, as its efficacy was more or less dismissed by SETI researchers some twenty years ago. The main reason that the laser approach to SETI has been given a bad 'press' is the assumption that ETIs lack the skills to target narrow optical beams into selected stars. This assumption of ineptitude is shown to be erroneous, and calls into question some aspects of the rationale for Microwave SETI. The detectability of both continuous wave and pulsed visible/infrared laser signals is described in some detail.

In every society throughout history key decisions have been based on economics. Constrained by the technology of their day, each society always have more demands on its wealth than it can readily dispense. There are always competing recipients of the same limited funds (i.e., new post office building or another C-17 transport). This paper shows why the laser is a far more economic choice than RF or microwaves for transmission over many light years. This is based on antenna gain considerations, 'habitable regions' near a star, and knowledge of the star types that can sustain intelligent life.

SETI at infrared wavelengths is discussed, and relative advantages or disadvantages of searches at various wavelengths, including microwave SETI, are analyzed. The mid-infrared appears to be one of the most favorable regions for a SETI.

Present research supporting the Search for Extraterrestrial Intelligence (SETI) and Communications with Extraterrestrial Intelligence (CETI) is almost entirely focused upon microwave wavelength and technologies. This paper demonstrates compelling reasons why the search should be broadened to optical wavelengths. Previous calculations of laser transmission efficiency are shown to be incorrect because an essentially lossless laser transmission system is feasible and star noise can be rendered inconsequential. New perceptions regarding the feasibility of laser technologies, together with reassessments of signal-to-noise considerations, indicate both the feasibility and desirability of optical interstellar transmissions, particularly at infrared and visible wavelengths.

A review of the SETI activities in the southern hemisphere over the past three decades is made. A description of the META II program, that is carried out from the Instituto Argentino de Radioastronomia (IAR), and that is continuously scanning the southern skies is described. META (Megachannel Extraterrestrial Assay) is an 8.4 million channels spectrum analyzer with a spectral resolution of 0.05 Hz, working at the 1,420 MHz hydrogen line at the Oak Ridge Harvard radio-observatory and at IAR. A description of the first optical SETI observing program from the southern hemisphere is made. For this purpose a high temporal resolution device called MANIA (Multichannel Analyzer of Nanosecond Intensity Alterations) will be used at the 2.15 m telescope of CASLEO (Complejo AStronomico El LEOncito) in the San Juan province in Argentina.

Electromagnetic SETI searches since 1960 have used a variety of search strategies. They have sampled 22 octaves in frequency with widely different sensitivities and sky coverages. Searches used a variety of detection bandwidths and data processing techniques, and consequently, the signals to which they were best matched differed greatly. Since the methods of extraterrestrial signaling are unknown, one cannot be certain of the relative merit of SETI searches. However, under plausible assumptions about the distribution of signal parameters, it is possible to evaluate all prior and proposed searches. The approach presented here assesses search merit under assumptions of either uniform or logarithmic distribution of signaling parameters such as pulse length. Under both assumptions, NASA's radio search is the most powerful to date. This is due to its high sensitivity, obtained at the cost of large computational load, and extensive frequency and sky coverage for many signal types.

Very low duty cycle short pulse high peak power laser modulation enables sending of signals great distances with low average power and high efficiency. Significant information can be sent by each pulse in digital pulse position modulation when M is very large. Direct detection can be utilized, enabling use of photon buckets, because the signal energy in a short pulse can overcome the generated noise by the star's spectrum. Exact optical frequency knowledge is not required because of the high background discrimination of the short pulse approach, although Fraunhaufer lines offer possible choices. Pictorial data is feasible and readily reconstructed using this modulation approach. The ability to use photon buckets enables the construction of large area collectors at low cost.

In the companion review paper on so-called Professional Optical SETI, it was suggested that ETIs are more likely to use lasers to contact emerging technical civilizations, and that such optical ETI signals will have very high EIRPs. This paper further proposes, that it is a sensible activity for amateur optical astronomers to construct their own Optical SETI observatories. Details are given of the equipment required and the approximate costs. The author describes the Optical SETI Observatory which is presently under construction in Columbus, Ohio. A coordinated Amateur Optical SETI (AMOSETI) activity could make a useful contribution to SETI research by conducting a low-sensitivity Targeted Search in the visible and near-infrared spectrum. This could be done in parallel with the present NASA Targeted Search that is part of the High Resolution Microwave Survey (HRMS). Signal processing techniques and data-handling procedures developed for this AMOSETI research activity, would set the stage for NASA's eventual extension of HRMS into the optical regime.

Progress in the NASA-funded optical communications program at the Jet Propulsion Laboratory (JPL) is described. This description includes a system-level breadboard for an optical communications flight package, the planning for the Earth-reception facilities, and the results of a recent optical communications experiment to deep space with the Galileo spacecraft.