Stories, Conjectures, Evidence and Proof

OK, we need to clear a few things up here.  People throw around words like "evidence" or "proof" a mite too loosely for my liking.  In an earlier post, I talked about evidence for the "hypothesis" (yes, scare quotes) that some UFO sightings are alien spacecraft, and why it's not so straightforward to say that.  And yet, almost everyday we hear claims of proof or evidence both for and against.  Let's talk a bit about what that means.

 

Short Version

 Evidence isn't just evidence - it is evidence for or against something.  Before that, it's just data, or worse, stories.  In order for data to serve as evidence we need to be able to fullfill three conditions:

1. We need a decent idea of what that something is and how we expect it to behave, i.e. a Hypothesis.
2. We need at least an approximate idea of how the data we have or propose to gather could be produced if the hypothesis was true (and, if it false).
3. We need to bend over backwards to honestly ask and answer the question: what if I'm wrong?  You can be wrong about the hypothesis, or you can be wrong about the evidence, and data can be just noisy or biased.

When you have all these things in place, and the odds that the data we have if your hypothesis is true are greater than the odds of the same data if the hypothesis is false, then you can claim that there is evidence for your hypothesis.  Not proof - proof means that your hypothesis is logically unavoidable, which is a much stronger (and almost certainly wrong) claim.

This leads us to problem we get with stories as evidence.  Also, with such conjectures as ghosts, alien spaceships, or cryptids  - we can't fulfill the first two conditions listed above, so are lost in claiming that some data we have is evidence for that.

What's not wrong with the ETH

Gort is not pleased with us

OK, I just got through slamming the ETH to the deck, and I have it in a sleeper hold, waiting for it to go limp.  Why would I defend it?

Recall that my main problem with the Extraterrestrial Hypothesis (ETH) is the "Hypothesis" part.  It's not so much the answers it offers, but that it fails to ask useful questions that we can answer with real data.  However, I feel that I must also address some the attacks the ETH has unjustly suffered, as well as some of the false distinctions it is included in.

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.


This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.