When is absence of evidence = evidence of absence?

You often hear the old mantra "absence of evidence is not evidence of absence," but I think that this is an oversimplification. The truth is, sometimes it is, and sometimes it isn't. It depends on the experiment, and also how well you understand the implication of the results.

There are times when you can make an excellent case that something is absent because there is no evidence of it. If you are is small, well-lit room, you probably don't need to look under many things to convince any reasonable person that there is no tiger there. In general, you need two things:

1. You need a solid argument for what sort of evidence you would expect if what you are looking for is there, and how that would be different from the null hypothesis (not there). 
2. A set of data that tends to falsify the hypothesis, thus advancing the null hypothesis.

We're not talking about "proof" here. I would just as soon we not talk about proof much at all, unless the topic is logic or mathematics. Rather, simply raising or lowering the odds of the null hypothesis, i.e. that the claim in question is not true.

The Skeptical UFO Investigator, Part 1.

This post is a companion to the talk I gave at Balticon 47, and is for people who would rather not watch the video, or would like more more details not in the video.

I've been investigating UFOs for over a year now, and plan to continue. Rather than explain exactly why this is, I am going to try and show you, one bit at a time. Much of the interest is driven by the human element, but perhaps not all of it.

As I have explained before, I don't know whether the Earth has ever been visited by non human intelligences from elsewhere, and I think it's highly unlikely that anyone else does either. I am skeptical we would know it when such an encounter was happening, though right in front of us. Our perceptions of such events would be fragmentary and distorted, and we would likely interpret them as magic, or supernatural.

Encounters of that very sort have been recorded all through human history, and continue to this day. Puzzling, often frightening, and frequently life changing events take place every day. Many of these, it turns out, are due to known bugs in the human perceptual and conceptual machinery, and others are merely hoaxes. UFO investigation has a more than 60 year history, and the truth continues to elude. I want to know why this is.

Let's go and have a look, I say, and let's see for ourselves what is going on.  Woody Allen once famously said that 80 percent of life is just showing up.  Let's show up where the saucers are seen and look for whatever patterns are there.

Homework from Professor Shostak

Seth Shostak may be right about UFOs,or he could be wildly wrong, but it is difficult to ignore his critiques of the the notion that UFOs are spacecraft from other planets. The SETI astronomer and podcast host recently appeared on Martin Willis' Podcast UFO to explain his views, which are also laid out in Chapter 4 of his book, Confessions of an Alien Hunter.

The so-called Extraterrestrial Hypothesis

Dr. Susan Blackmore is a little weird and more that a little smart.  She received the first ever British PhD in parapsychology, and believed in Tarot reading, out of body experiences, and psychic powers.  She was sure she could prove the existence of psychic abilities to even the most die-hard skeptics by amassing methodologically bulletproof evidence from a wide variety of experiments in clairvoyance and precognition, i.e. psi.   At the time, the whole field of parapsychology felt they were on the verge of breaking through to mainstream acceptance.

After a grueling series of consistently negative results, Blackmore began to be troubled by the definition of psi.  Psi was defined as whatever is causing psi experimental results to deviate from pure chance.  That is what psi isn't, but what is it?  Strengthening the methodologies made the signal drop down into the noise.  After repeated failures and not being able to define what to really test for, Blackmore soured on the very concept of psi and turned her research focus on to other things.

When it comes to UFOs, there is a shopworn old meme lying around frequently known as the Extraterrestrial Hypothesis (ETH for short).  It still attracts both derision and True Belief.  The ETH can be summed up simply as: some fraction (usually quoted at around 10%) of UFO reports are the result of something intelligently controlled that is not from Earth.

Do you see the problem?  It's analogous to the negative definition of psi.  By asserting that some UFOs - the otherwise hard to explain ones - are craft from outer space, we are really just stating what they are not - they are not ours.  But what ARE they?  A good hypothesis tells us where to look, and what information we can use to test the hypothesis.  The so-called ETH does not do that.  It's not a hypothesis!

Since aliens are very likely queerer than we can imagine, an alien spacecraft could be anything, and we would very likely not be able to perceive or describe it completely or accurately.  I won't address here the problem of the sparse, uneven quality of UFO data, or the thorny question of what phenomena to include, but even if we had terrifically good data, we still have no bonafide hypothesis to test it against.  "Not from here" doesn't fit the bill, and at this point, we don't know where to turn.  What happens in practice is that each of us invents our own private mental model of a single human-like alien race and wonder why UFOs don't behave that way.

Is there hope for the old ETH?  Not as such, but I believe it will have better successors. I do hope for really high quality hypotheses about the nature and behavior of alien intelligent life that we can really use.  The study of alien life, especially intelligent life, is pre-paradigmatic right now and starved of hard data.  We're going to need lots more information, and not much of it will be about UFOs (although I hope I am wrong).  The new emerging science of astrobiology will probably tell us much more about the constraints on development of intelligent species than any of our deeply flawed perceptions and memories of things we are unlikely to understand at all.

Nearly all hypotheses we develop about alien intelligences are likely to be wrong. Wrong, but the work of proving them wrong will lead us places we can't see at all right now.


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UFO Busters

I have a low opinion of the new National Geographic show "Chasing UFOs."  Although I find the cast fairly likeable, the production is just laughably corny and the cases tend to be silly, content free, or have been long put to rest.  However, what's not to like about seeing Jaime Maussan's marmoset hoax roundly debunked?  That buffoon can not be put down hard enough.

The problem with any UFO show is that the better the job you do, the more the entertainment value is likely to be low.  Most cases evaporate immediately, most of the rest lack sufficient evidence for serious investigation, and the few that remain come along only very rarely and there is nothing to "chase." Instead of modeling their show after the laughably hokey ghost hunting shows, Nat Geo should look instead at the very successful Mythbusters as a model.  Mythbusters has been hugely successful by showing people building things, solving problems, facing frustration,applying science, and wrecking things thoroughly.   Most of the myths are busted, but some are judged plausible, or even confirmed.  See how that could be a UFO show?  You're welcome, NatGeo.

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