SearchLites - Vol 21 No 4

Magazine Overview

Title: SearchLites
Issue: Vol. 21 No. 4
Date: Autumn 2015
Publisher: The SETI League, Inc.
Country: USA
ISSN: 1096-5599

This issue of SearchLites, the quarterly newsletter of The SETI League, Inc., explores a range of topics related to the search for extraterrestrial intelligence, mathematics, and astronomy. The cover story, "Irrational!" by Dan Duda, delves into the mysterious nature of irrational numbers, particularly Pi, and their potential connection to fundamental physics like gravity. The newsletter also features a Q&A section with "Dr. SETI," addressing reader questions about Project Argus, follow-up on past detections, and the use of spectrometers versus radiometers in radio astronomy.

Irrational!

Dan Duda's article "Irrational!" posits that the strangeness of numbers like Pi may hint at deeper mysteries in the universe, potentially related to gravity and the concept of a multiverse. He discusses how irrational numbers are essential for describing curved objects and how their infinite, non-repeating nature challenges our understanding of reality. The article touches upon the weakness of gravity compared to other fundamental forces and the ongoing search for the graviton, the hypothetical particle mediating gravity. Duda references Brian Greene's work on string theory, which suggests more than three spatial dimensions, and speculates that much of existence may lie beyond our current comprehension.

Following Up on Past Detections (Ask Dr. SETI)

A reader named "Anonymous" inquires about the strategy of Project Argus, which has shifted to intermittently scanning the whole sky, and asks if some telescopes could be dedicated to continuously monitoring known signal locations for repetition. "Dr. SETI" explains that while follow-up monitoring is vigorously pursued, Project Argus, designed as an all-sky survey with low-gain antennas, is not ideally suited for targeted follow-up. Such activities are better performed with high-gain, steerable antennas, like those of the Allen Telescope Array (ATA), which the SETI Institute is indeed using for this purpose.

Power Measurements with a Spectrometer (Ask Dr. SETI)

Another reader, "James," asks for clarification on using a SpectraCyber receiver with a Horn of Plenty antenna. He is confused about voltage output not being proportional to power and seeks a system that provides absolute power measurements, not just relative ones influenced by a baseline voltage. "Dr. SETI" explains that the Spectra Cyber is a spectrometer, not a radiometer, and thus not designed for absolute power calibration. He suggests that crude calibration can be achieved by comparing known hot and cold sources, but emphasizes that a spectrometer's measurements are inherently relative compared to a calibrated radiometer.

Event Horizon

This section lists upcoming conferences and meetings relevant to SETI research, including the International Astronautical Congress in Jerusalem and Guadalajara, the AAAS Annual Meeting in Washington D.C., and various SETI League events such as the Ham Radio QSO Party and Annual Membership Meetings. It also includes a promotion for AmazonSmile, encouraging readers to support The SETI League through their Amazon purchases.

Guest Editorials: Knowable and Unknowable

Michael A.G. Michaud's editorial explores the historical progression of scientific understanding, from the initial belief in Martian canals to the current search for exoplanets. He discusses how what was once considered unknowable can become knowable through technological advancement. The article highlights the Search for Extraterrestrial Intelligence (SETI) as an example of an endeavor that has moved from the realm of speculation to a scientific pursuit, despite a lack of confirmed detections after over 55 years. Michaud also touches upon the debate surrounding Active SETI (Messaging to Extraterrestrial Intelligence), raising concerns about the potential risks of provoking a response from unknown alien civilizations and the possibility of interstellar travel by machines.

SETI

Michaud notes that while SETI has faced challenges, the discovery of exoplanets has shifted the focus towards searching for evidence of life, which may be more common than technological intelligence. He suggests that future efforts might involve interstellar probes and that the search for extraterrestrial life could spark new thought experiments about the nature of evolution.

WHY DO WE SEARCH?

The article posits that the search for distant intelligence is an extension of normal science, driven by the hope that contact could bring new and positive factors into human affairs. It acknowledges that the search has inspired creative thought and raised philosophical questions, even without a discovery.

THE SECOND I

This section discusses how detecting habitable worlds or extraterrestrial life could boost optimism for finding ETI. It also considers the possibility that advanced civilizations might be indistinguishable from nature or that their communication methods might be beyond our current detection capabilities. The discovery of alien intelligence might not necessarily lead to communication, but rather an "existence proof."

TRANSITION

There is an implicit shift in emphasis from seeking deliberate signals of technological intelligence to searching for evidence of life, which may be more common. This shift is partly due to the disproportionate funding for planet-hunting compared to SETI.

EXPANSION

This section explores the idea of human expansion and the potential for finding habitable worlds as future homes for descendants. It discusses the ambition to travel to distant worlds and the possibility of interstellar probes. The author notes that while interstellar flight is possible, the lack of observed alien probes might be due to societal failures in agreement, perception, imagination, nerve, or politics.

WHO WILL LEAD?

The United States is expected to remain a major player in space, but a lack of consensus among elites may hinder long-term projects like interstellar exploration. China is presented as a rising power with a determination to succeed in great societal endeavors.

Recurring Themes and Editorial Stance

The recurring themes in this issue include the philosophical and scientific implications of irrational numbers, the ongoing efforts and challenges in the search for extraterrestrial intelligence, the impact of exoplanet discoveries on astrobiology and SETI, and the future of space exploration and human expansion. The editorial stance appears to be one of cautious optimism regarding SETI and space exploration, acknowledging the scientific rigor involved while also highlighting the uncertainties and potential risks, particularly concerning active SETI. There is a clear emphasis on the scientific method, data analysis, and the need for continued research and technological advancement.