As we puzzle out the best observing strategies to pick up a bio- or technosignature, we're also asking in what ways our own world could be observed by another civilization. If such exist, they would have a number of tools at their disposal by which to infer our existence and probe what we do. Extrapolation is dicey, but we naturally begin with what we understand today, as Brian McConnell does in this, the third of a three-part series on SETI issues. A communications systems engineer, Brian has worked with Alex Tolley to describe a low-cost, high-efficiency spacecraft in their book A Design for a Reusable Water-based Spacecraft Known as the Spacecoach (Springer, 2015). His latest book is The Alien Communication Handbook -- So We Received A Signal, Now What? recently published by Springer Nature. Is our existence so obvious to the properly advanced observer? That doubtless depends on the state of their technology, about which we know nothing, but if the galaxy includes billion-year old...

If you were crafting a transmission to another civilization -- and we recently discussed Alexander Zaitsev's multiple messages of this kind -- how would you put it together? I'm not speaking of what you might want to tell ETI about humanity, but rather how you could make the message decipherable. In the second of three essays on SETI subjects, Brian McConnell now looks at enclosing computer algorithms within the message, and the implications for comprehension. What kind of information could algorithms contain vs. static messages? Could a transmission contain programs sufficiently complex as to create a form of consciousness if activated by the receiver's technnologies? Brian is a communication systems engineer and expert in translation technology. His book The Alien Communication Handbook (Springer, 2021) is now available via Amazon, Springer and other booksellers. by Brian S McConnell In most depictions of SETI detection scenarios, the alien transmission is a static message, like...

If we ever do receive a targeted message from another star – as opposed to picking up, say, leakage radiation – will we be able to decipher it? We can’t know in advance, but it's a reasonable assumption that any civilization wanting to communicate will have strategies in place to ease the process. In today's essay, Brian McConnell begins a discussion on SETI and interstellar messaging that will continue in coming weeks. The limits of our understanding are emphasized by the problem of qualia; in other words, how do different species express inner experience? But we begin with studies of other Earth species before moving on to data types and possible observables. A communication systems engineer and expert in translation technology, Brian is the author of The Alien Communication Handbook -- So We Received A Signal, Now What?, recently published by Springer Nature under their Astronomer’s Bookshelf imprint, and available through Amazon, Springer and other booksellers. by Brian McConnell...

I always knew where I stood with Alexander Zaitsev. In the period 2008-2011, he was a frequent visitor on Centauri Dreams, drawn initially by an article I wrote about SETI, and in particular whether it would be wise to go beyond listening for ETI and send out directed broadcasts to interesting nearby stars. At that time, I was straddling the middle on METI -- Messaging to Extraterrestrial Intelligence -- but Dr. Zaitsev found plenty of discussion here on both sides, and he joined in forcefully. Image: Alexander Leonidovich Zaitsev, METI advocate and radio astronomer, whose messages to the cosmos include the 1999 and 2003 'Cosmic Calls' from Evpatoria. Credit: Seth Shostak. The Russian astronomer, who died last week, knew where he stood, and he knew where you should stand as well. As my own views on intentional broadcasts moved toward caution in future posts, he and I would have the occasional email exchange. He was always courteous but sometimes exasperated. When I was in his good...