"The timescales for technological advance are but an instant compared to the timescales of the Darwinian natural selection that led to humanity's emergence -- and (more relevantly) they are less than a millionth of the vast expanses of cosmic time lying ahead." -- Martin Rees, On the Future: Prospects for Humanity (2018). by Henry Cordova This bulletin is meant to alert mobile units operating in or near Sector 2921 of a potential danger, namely intelligently directed, deliberately hostile, activity that has been detected there. The reports from the area have been incomplete and contradictory, fragmentary and garbled. This notice is not meant to fully describe this danger, its origins or possible countermeasures, but to alert units transiting near the area to exercise caution and to report on any unusual activity encountered. As more information is developed, a response to this threat will be devised. It is speculated that the nature of this hazard may be due to unusual manifestations...

It seems a good time to re-examine the venerable Kardashev scale marking how technological civilizations develop. After all, I drop Nikolai Kardashev's name into articles on a regular basis, and we routinely discuss whether a SETI detection might be of a particular Kardashev type. The Russian astronomer first proposed the scale in 1964 at the storied Byurakan conference on radio astronomy, and it has been discussed and extended as a way of gauging the energy use of technological cultures ever since. The Jet Propulsion Laboratory's Jonathan Jiang, working with an international team of collaborators, spurs this article through a new paper that analyzes when our culture could reach Kardashev Type I, so let's remind ourselves of just what Type I means. Kardashev wanted to consider how a civilization consumes energy, and defined Type I as being at the planetary level, with a power consumption of 1016 watts. This approximates a civilization using all the energy available from its home...

Early exoplanet detections always startled my friends outside the astronomical community. Anxious for a planet something like the Earth, they found themselves looking at a 'hot Jupiter' like 51 Pegasi b, which at the time seemed like little more than a weird curiosity. A Jupiter-like planet hugging a star? More hot Jupiters followed, which led to the need to explain how exoplanet detection worked with radial velocity methods, and why big planets close to their star should turn up early in the hunt. Earlier, there were the pulsar planets, as found by Aleksander Wolszczan and Dale Frail around the pulsar PSR B1 257+12 in the constellation Virgo. These were interestingly small, but obviously accumulating a sleet of radiation from their primary. Detected a year later, PSR B1620-26 b was found to orbit a white dwarf/pulsar binary system. But these odd detections some 30 years ago actually made the case for the age of exoplanet discovery that was about to open, a truly golden era of deep...

Just a quick note for today as I finish up tomorrow's long post. But I did want you to be aware of this new title, Extraterrestrial Intelligence: Academic and Societal Implications, which has connections with recent topics and will again tomorrow, when we discuss a new paper from Jason Wright and SETI colleagues on technosignatures. As with the recent biography of John von Neumann, I haven't had the chance to read this yet, but it's certainly going on the list. The book is out of Cambridge Scholars Publishing. Here's the publisher's description: What are the implications for human society, and for our institutions of higher learning, of the discovery of a sophisticated extraterrestrial intelligence (ETI) operating on and around Earth? This book explores this timely question from a multidisciplinary perspective. It considers scientific, philosophical, theological, and interdisciplinary ways of thinking about the question, and it represents all viewpoints on how likely it is that an...

We can’t know whether there is a probe from another civilization – a von Neumann probe of the sort we discussed in the previous post – in our own Solar System unless we look for it. Even then, though, we have no guarantee that such a probe can be found. The Solar System is a vast place, and even if we home in on the more obvious targets, such as the Moon, and near-Earth objects in stable orbits, a well hidden artifact a billion or so years old, likely designed not to draw attention to itself, is a tricky catch. As with any discussion of extraterrestrial civilizations, we’re left to ponder the possibilities and the likelihoods, acknowledging how little we know about whether life itself is widely found. One question opens up another. Abiogenesis may be spectacularly rare, or it may be commonplace. What we eventually find in the ice moons of the outer system should offer us some clues, but widespread life doesn’t itself translate into intelligent, tool-making life. But for today, let’s...