I've recently published an essay collection titled Essays on UFOs and Related Conjectures: Reported Evidence, Theoretical Considerations, and Potential Importance (free PDF; 2nd edition with a new chapter). It is available for free on Amazon, Smashwords, Apple Books, Barnes & Noble, and elsewhere.

Here is a brief description:

Essays on UFOs and Related Conjectures invites readers to reflect on their beliefs and intuitions concerning extraterrestrial intelligence. The essays in this collection explore the extraterrestrial UFO hypothesis, optimized futures, and possible motives for a hypothetical extraterrestrial presence around Earth. Some of the essays also delve into the potential moral implications of such a presence. Overall, this collection makes a case for taking the extraterrestrial hypothesis seriously and for further exploring the evidence, theoretical considerations, and moral implications that may relate to this hypothesis.

The essays found in this collection are the following:

What credible UFO evidence?
Can we confidently dismiss the existence of near aliens? Probabilities and implications
What might we infer about optimized futures?
From AI to distant probes
Silent cosmic rulers
Why UFOs matter
Comparing UFO origin hypotheses: Ancient Earth vs. ET and intra- vs. intergalactic

Below is a slightly abridged preface.

Preface

This essay collection explores the subject of UFOs and related conjectures. A key aim throughout most of these essays is to question strong assumptions that we might have accepted too uncritically, and which we may need to reconsider and recalibrate. In other words, the essays found here challenge some of our deep-seated intuitions, and they generally point toward a more open-minded and agnostic outlook than what we are used to.

0.1 Clarifying the scope

There are many hypotheses that one can explore with respect to the potential origin of seemingly anomalous UFOs. For example, beyond explanations that involve perceptual errors, there are various hypotheses that imply advanced technology with a human origin, such as governments or private groups. Alternatively, there are hypotheses that involve ancient origins on Earth, according to which some animal species developed advanced technology long before the first humans appeared.

The essays found here mainly focus on the extraterrestrial hypothesis (concerning the origin of at least some seemingly anomalous UFOs). The reason for this focus is not that I dismiss competing hypotheses, but simply because the extraterrestrial hypothesis seems plausible enough to be worthy of exploration in its own right.

0.2 Extraordinary claims?

When it comes to the possibility of advanced extraterrestrials visiting Earth, it is often quipped that “extraordinary claims require extraordinary evidence”. I suppose this can roughly be translated into the following: for any hypothesis to which we assign an extremely low prior probability, it takes strong evidence for us to assign it a high posterior probability (so far so good), and the hypothesis that advanced extraterrestrials are visiting Earth is a hypothesis to which we should assign an extremely low prior probability. But is this latter part really true?

Similarly, it is sometimes said that discovering the presence of advanced extraterrestrials around Earth would be a paradigm-shattering event. But is this true? In what sense would this prospect be “extraordinary” and “paradigm-shattering”? It seems to me that there are two distinct notions of both “extraordinary claims” and “paradigms” that are worth distinguishing here, namely social and epistemic ones.

Obviously, the discovery of advanced extraterrestrials around Earth would be extraordinary in the sense that it would have extraordinary social implications, and it would likewise shatter our social paradigm, which is centered on the idea that humans are the most powerful creatures around. However, this should not be confused with what we may call extraordinary epistemic claims that shatter our epistemic paradigm — that is, claims that are extremely surprising and revolutionary relative to what our best current knowledge would predict. After all, a prospect can have extraordinary social implications and shatter our social paradigm without necessarily being epistemically extraordinary or paradigm-shattering. An example might be the predictable rise of a dangerous dictator, or the creation of nuclear weapons based on known physical principles.

So, notwithstanding its profound change in our social paradigm, would the discovery of advanced extraterrestrials around Earth be epistemically extraordinary and epistemically paradigm-shattering? Well, if we step back and reflect on it, arguably not. In terms of our modern understanding of the world, such a presence is not necessarily the most likely hypothesis a priori, but it would still seem to fit quite well within our current scientific paradigm.

After all, we know that life evolved on our planet through natural processes; we know that there are innumerable planets throughout our galaxy and beyond; and we know that the universe is old enough for advanced civilizations to potentially have emerged many millions, if not billions, of years before the first humans emerged.

In light of this modern picture — which departs radically from the geocentric picture that was dominant a few centuries ago — it would hardly be that surprising if there were advanced extraterrestrials in our region of the cosmos, and if they had traveled here. (Them traveling here may be surprisingly likely conditional on them existing in our region of the cosmos, since advanced extraterrestrials could travel far in millions of years.)

In other words, from a brief glance at the big picture, our prior probability on “advanced extraterrestrials visiting Earth” should arguably not be extremely low, and hence this prospect is arguably not all that extraordinary in epistemic terms, even if it very much is in social terms. Indeed, one could argue that the conjecture lies squarely — and even quite boringly — inside the broad confines of our modern scientific paradigm, like a grey clump of “what you might predict if you put your base ingredients together”. This is presumably also why Fermi already in 1950 asked where everybody is: because that question reflected a fairly natural prediction of the known paradigm, even decades before we discovered that exoplanets are more numerous than cat videos on the internet.

Yet perhaps our outlook is still secretly stuck in the geocentric-anthropocentric picture, and perhaps our myopic social paradigm is clouding our scientific and epistemic outlooks. Perhaps we have yet to catch up with the implications of our modern worldview, and to appreciate what would be plausible and implausible in light of what we currently know about the cosmos, even if it might be socially and existentially uncomfortable.

0.3 Brief overview of the content: Invitations to reflect

This essay collection is, among other things, an invitation to reflect on the prior probability that we assign to the possibility of advanced extraterrestrials around Earth. That is, it is an invitation to reflect on the probability we assign to this prospect before looking at any purported UFO evidence. I explore various well-known arguments in favor of a low prior probability, while also presenting arguments that seem to favor a fairly high prior. Overall, it seems to me that the balance of arguments suggests that the prior probability should not be particularly low. But either way, my primary aim in exploring these arguments is to invite deeper reflection on our priors, as opposed to mainly relying on unexamined intuitions.

Beyond reflections on priors, some of the essays also explore relevant Bayesian likelihoods. (A Bayesian likelihood is the probability of observing some specific evidence conditional on a given hypothesis being true.) In particular, the likelihoods explored here concern what we should expect to observe conditional on an advanced extraterrestrial presence around Earth. Here, too, I explore arguments that may question some of our deep-seated intuitions and assumptions. Indeed, this might be where we harbor the strongest and least examined intuitions — not in our priors, but rather in our expectations about what we should observe if there were advanced extraterrestrials in our backyard. I will say more about this in the second essay of this collection.

In addition to these theoretical considerations, I will present a list of UFO reports and incidents. I do not seek to analyze these reports; I merely present them here because I think they are worth taking a closer look at, and because many of them can otherwise be quite difficult to find. These reports are found in the first essay of this collection, and they provide some initial motivation for the theoretical explorations that follow. Such reports may likewise give us reason to reflect on and reconsider our long-held intuitions.

Finally, some of the essays seek to invite reflection on the moral implications of the extraterrestrial hypothesis: if there are advanced extraterrestrials around Earth, how, if at all, should our moral perspectives and priorities change? My exploration of these questions is highly preliminary, and it mostly seeks to advance the questions themselves.

0.4 Why I have written these essays

It might be helpful to provide some background as to why I have written these essays. The overriding focus of my work is to reduce extreme suffering, and a key focus area in this regard is to reduce risks of astronomical suffering, or s-risks — risks of severe suffering occurring on a scale far greater than anything that has taken place on Earth (see e.g. Tomasik, 2011; Althaus & Gloor, 2016; Baumann, 2017; 2022; Vinding, 2020, ch. 14).

While the potential existence and future of extraterrestrial intelligence may seem rather exotic relative to most of our concerns, it is in fact a rather natural issue to explore in the context of reducing s-risks, as well as when considering the future of suffering more broadly (see e.g. Tomasik, 2011; Knutsson, 2021, sec. 4; Vinding & Baumann, 2021; Cook, 2022; Buhler, 2023).

Indeed, even relatively modest changes in our probabilities and models regarding the future of extraterrestrial intelligence may have significant implications in terms of how we can best allocate resources for reducing suffering. For example, as I will argue, increasing our estimated probability of advanced extraterrestrials around Earth would plausibly imply a greater focus on preventing suffering in the relatively near future and less on preventing suffering in the long-term future. Our beliefs about these questions have real-world implications, and hence it makes sense to explore evidence and considerations that may help sharpen these beliefs.

A related reason I have written these essays is simply that the topic seems extremely neglected. This is especially true from my perspective of exploring the potential implications for reducing suffering, yet it also seems true at a more general level. In particular, something that seems broadly neglected is to explore the strong assumptions that tend to underlie people’s views on these topics, and not least to look at the subject of UFOs from a serious theoretical perspective (cf. Hanson, 2021).

That is, some common attitudes and approaches toward UFOs are to either (1) completely dismiss the topic, (2) to immediately endorse a given hypothesis, or (3) to believe that the chief priority with respect to UFOs is to simply collect more data while holding back from theorizing. Yet while data is essential for understanding a given phenomenon, so is theory — and serious theorizing is notably absent from each of the three approaches outlined above.

By “theory”, I don’t here mean some singular overarching theory, but rather the diversity of theoretical considerations that are relevant to our overall views and assessments of a given topic. It has to do with the kinds of probabilistic predictions and inferences we might make based on our current best models and guesses about the world.

In my view, theory — in this broad and cautious sense — is plausibly what is most neglected when it comes to the subject of UFOs and the extraterrestrial hypothesis. Likewise, it seems to me that many core beliefs about this subject have their basis in implicit assumptions that are theoretical in nature (e.g. assumptions about whether there is any plausible theory that is compatible with barely visible advanced extraterrestrials around Earth). Thus, engaging with theory and theorizing seems critical for evaluating and refining those assumptions.

This view of the neglect and importance of theory also partly explains why most of the essays found here primarily consist of theoretical considerations.

0.5 Final prefacing notes

There is hardly a great way to say the following, but I feel it is nevertheless worth saying: when writing about UFOs and related conjectures, it is extremely easy to be misunderstood. For example, it is easy for one’s claims to be misinterpreted as being much stronger than they are, even when one writes qualifications and caveats ad nauseam. I think this is worth saying so as to highlight a certain inclination that seems common when approaching texts on this issue, namely the inclination to jump to strong conclusions and interpretations about what is being claimed. (Of course, this inclination may be present when we read about most issues, but my impression is that it is especially strong when it comes to this issue.)

Perhaps some helpful heuristics for avoiding this pitfall include being deliberately slow in forming interpretations, being cautious about drawing strong interpretations, and paying attention to caveats and qualifications. Yes, making these remarks at the outset is inelegant, but my experience suggests that it may be helpful.

It is my hope that the essays found here can help stir further reflection on questions about UFOs, extraterrestrial intelligence, and how we can best reduce future suffering given our current state of uncertainty.