Saturday, December 20, 2014

Evidence: fallacies of authority

So, to recap the prior post, it is that we find evidence of things (or lack thereof, in some cases, is evidence itself) that happened before we could directly observe them, and explained why this indirect evidence is important, and testable.

Now we're going on a bit of a caveat, since it seems to be ingrained in the idea that it is evidence.

Someone said they doubt a portion of some theory, so the entirety of said stance is incorrect.

  Let's think about this for a moment, because it really hits home at some very important points in the nature of how science works.  This also illustrates a couple of common fallacies.

Since this is a series on evidence, we'll start there.  Let's go again to the first part of that sentence.  Doubt is a natural, skeptical process.  It's how science works.  But doubt isn't simply someone saying they think something could be wrong. Simply disagreeing to disagree in spite of evidence is cynicism, not skepticism.  Furthermore, saying that someone happens to have doubts about something in a theory/hypothesis doesn't make the theory/hypothesis wrong.  It merely means that, perhaps, a small portion is somehow incorrect.  This has happened a lot of times.

Let's take a simple example, Newton's theory of gravity (that's a scientific theory, so please take a moment and clarify that again).  Newton's theory works fine for most of our interactions, and it works to a degree of clarity that's pretty astounding, given the tools and abilities of people several centuries ago.  Newtonian physics didn't deal with the speed at which gravitational waves propagate, for example (waves are interesting things when you leave the macro world for the micro/quantum, but I digress - that's not the scope of this post, and I'm not the best person to discuss that anyway).  Some people had doubts as to whether they really moved at the speed of light. 

Now, to say the doubts about whether they move at the speed of light, whether they propagate instantaneously, or whether they're slower (like ocean waves, sound waves, radio waves, etc) doesn't change the fact that the rest of the theory works well.  It also doesn't invalidate Einsteinian Relativity for Einstein to question this very thing himself.  Newtonian gravity works excellently for things at short distances (say, within a few hundred million miles, like our distance from the sun, or the distance of a basketball hoop from the center of the earth, say), but starts to fall apart at larger distances.  Even Newton was (probably) well aware of this. 

With this foundation, let's look a bit closer at the second part of the argument above.  Just because we didn't know how fast gravity waves moved, doesn't mean there aren't gravity waves, and it doesn't mean they don't move.  It's exactly the same conundrum when people say that there are things we don't understand about evolution, so evolution must be incorrect.  It's simply not true, and it's an appeal to authority fallacy.

Let's pop this on it's back and reverse it.  There's two clear-cut examples, one biblical, and one more recent.  In the bible, Jesus questions whether or not his father is really sure about what to do.  Jesus questioned his own existence, essentially.  This does not, by itself, mean that the bible is wrong.  Jesus had doubts about his father's plan, so maybe his father's whole plan was wrong.  Again, this is an argument from appealing to authority, and it's a fallacy.  To put that in modern terms, tons of biblical scholars are even pretty sure Jesus didn't actually exist (they doubt the bible), and therefore since they're the learned ones of the bible, we should just accept that their whole hypothesis is wrong too, because one part of it is in doubt by someone who should know these things.  That's a bad fallacy, but no one seems to like bringing it up.

Essentially, this is exactly what the popes do ALL THE TIME.  They change stances, doubt the biblical things that shouldn't be doubted if it's the literal word of god.  But, as simple as that would make my job, it doesn't invalidate the bible just because people don't know it all to be true.  The evidence, you see, is what bears negatively on the bible.  There's literally no evidence for, and plenty of that direct and indirect evidence against, the historical account of the bible.  If that changes, and we find fossils in the wrong strata, or perhaps we find a particular element that measures a different half-life than all the same samples we've ever found before, then the science would change.  Those fossils in the wrong place would be pretty strong evidence of someone moving them.  In a million years, perhaps, another species might see tons of localized fossils that don't belong in our strata that we've moved.  And even if all this happens, it still isn't evidence (direct, indirect, induced or otherwise) for a creator, especially not a specific one. 

Until such time as we have such evidence, and can test it, and make predictions with it, the doubt Dawkins has about tiny parts of the theory of Evolution do not make the theory invalid.  It simply means someone doubts part of it (and probably with at least a bit of evidence), nothing more.  Evidence is required for the next step, which is changing the theory.  If we found solid evidence of a creator, then our theory would have to include it, regardless of who doubts it. 

The key takeaway here is that doubt by one party is not evidence for another.  Cherry-picking that doubt as evidence is actually quite another fallacy, and is intellectually disingenuous at best.  It may be a formal unwarranted assumption, but I think it's more correctly a fallacy of absence of evidence.  It is most definitely, however, a confirmation bias.  Just because someone doubts a portion of something doesn't mean you can then say that's justifiably a way to show it incorrect in absence of evidence that you don't have.  You need evidence to demonstrate your point just as much as the other needs evidence to have doubt in his.  This seems convoluted, but that's what happens with fallacious thinking.

Evidence and corollaries.

So, bearing in mind the things we discussed in the last post, let's move forward a bit.  The story of Noah is a great one, but I think I've made my case reasonably.  Also, lots of other people have handled this one anyway, so lets work on something rather more productive.

Let's start with the various complaints that theists tend to levy against atheists.  And since we're talking evidence, we'll take it from a straightforward evidence standpoint.  This will be mostly slanted toward Christianity since it happens to be the religion I'm most familiar with.  Though, I'm actually at home for this post, so I can do rather more research if need be.  These are just going to be logical points, however, so it shouldn't require much.

Also, I think I'm going to do a series of these in a row, one post for each sort of thing I happen to run into.  STAY TUNED!

First fallacy: You weren't there, so you can't know what happened.

 Let's break this down.  Absolutely correct, first sentence portion. I wasn't there, you were not there, no one alive today was there.  

Second sentence portion, you disappoint me.  It's like you didn't even read the former blog post.  It's similarly as though you've never witnessed the after-effects of something.  Fires are simple, and we'll stick with them.

Let's run a thought experiment here.  Imagine you've come upon a pile of ashes in the woods.  You know there's approximately one way to make ashes, by burning things.  The ashes are in a neat pile that looks rather like it was the remainder of something that happened in this particular spot.  The pattern of the ashes is such that the coloration is variegated.  These are all pretty clearly signs of something.  It's entirely possible someone carried some ashes, that were produced in the absence of fire, to this very location.  It's possible also that someone artfully and masterfully made the whites and blacks of the ashes look like sticks of wood had burned.  It is much more likely, however, that a fire was here and someone left the remainder of it thus.  The evidence supports both conclusions, but the explanation that requires the least extraordinary thing to be true tends to be true. 

Let's go one more round here.  I'm wearing a shirt.  This is pretty clear evidence that I (or at least someone) put the shirt on at some point.  It is also evidence that perhaps the shirt simply wove its fabric together around my torso, but that takes rather more explanation.  Also, a machine that makes shirts on the torso every morning would be pretty neat.

It is through logic this way we can sort out the likeliest of scenarios.  This also has a corollary: it is this way we can also sort out the least likely of scenarios.

But back to the argument, now that we've our basic ideas laid forth.  You're absolutely correct, we weren't there when the fire burned.  It's entirely possible the ashes popped into existence.  The evidence is much stronger that there was simply a fire here.  Just saying I wasn't there isn't evidence that there was no fire, in exactly the same way me saying you weren't there isn't evidence that there was a fire.  Man, that sentence was hard to think about - logical fallacies are hard to weave.

So let's say you take the opinion that there was no fire.  That's absolutely wonderful skepticism.  Now, you need only provide evidence.  Remember, evidence has to be testable.  So I show you a stick.  I light it on fire.  It burns and produces ashes strikingly similar to the ashes in the pile.  We'll keep this one simple and halt there for our methods.  Logically, I now ask you to produce evidence.  You take a stick, and can do nothing to it that produces ashes, least of all bearing any resemblance to the pile before us (in this simplistic argument, fire makes ashes of this nature - lightning strikes produce much different patterns of ashes, say, which are inconsistent with this pile in front of us). 

To say that I simply wasn't there, that's fine.  You weren't either.

Also, whilst we are on this topic, one important tangent.  Saying that evidence is faulty, or that there isn't evidence (while ignoring actual evidence or simply not knowing of it, and then denying it when it's presented), but not producing counter-evidence to support the (in)validity of the evidence you are rebutting, is not evidence.  Just disagreeing isn't evidence.  Creating a testable observation is.

It is these testable observations for which all of science operates.  Evidence is not just direct and indirect, though you could simply call inductive logic (and evidence) either one, depending on it.  For example, we also 'see' directly the evidence of fires that didn't happen by things that haven't burned down.  The tree in my back yard that's still standing is evidence that someone hasn't burnt it down (or cut it down or any number of other things that leave various signs as to what happened), in exactly the same way as ashes are evidence of a fire.

Putting this in evolutionary perspective, for example, we can test strata, see what lives in them, and equally importantly what doesn't, and both are evidence.  The evidence of absence is not the absence of evidence (don't run that backward all the time though, you're bound to get false causality fallacies sometimes) as Colin Powell once tried to say, but ended up with a horrible fallacy all his own...

See you all on the next one!

Friday, December 19, 2014

On the nature of evidence: the requisition of science

Evidence is a wonderful thing.  It shows us what is real and what sorts of things to be true in our universe.  This is why it is important to understand the role it plays in our lives, as well as the sort of rigors that are required to ensure science remains as objective as possible.

Note: this article isn't discussing the difference between evidence and proof. I am going to treat the terms as completely commensurate for this post to avoid semantic posturing and pedantry.

Some people have a hard time understanding what evidence is.  Evidence comes in two forms, and both are based on observation. 

The first type is direct evidence.

Some evidence we can view, touch, taste, feel.  Direct evidence for a fire is watching it burn.  Direct evidence for waves and tides is watching them on the coast at the ocean, for example. 

The second type is indirect evidence.

Some evidence is observable after the fact, or in the absence of things we can do right now.  Ashes are a good indicator that something was, at one time, on fire.  The sides of cliffs eroding in particular ways, or accumulating things to only a certain level, are good evidence of waves and tides, respectively.
Understanding this is key to understanding science, and to scientific understanding of nature.

This is where it is important to understand things that are not evidence.  A science textbook is not itself evidence for science.  It is a textbook that explains testable things that have happened in the past ( note: in a meta sense, any book is evidence for science because you can do things to the books, like set them on fire or weigh them to measure gravity or test their ability to withstand ionizing radiation...).  The fact that a science text exists (and there are write a number if science and math texts in the world) doesn't make it evidence for the things contained within.  The fact that we can test the ideas contained within, however, does.

This same rule applies to any text. The bible is not, as Ken Ham implies (for example), evidence for the Genesis creation story.  (Again, in a meta sense, we can and are testing the ideas there too - Sodom was probably pretty tame compared to Las Vegas, but it still thrives.  China is considerably less Christian than the ancient Midianites, but still it stands).

This tends to trip up people a bit, who think that creation and evolution have the same credibility.   Lots of religious people want to say, for example, that the fossil record is faulty or too incomplete to make an informed decision.  Let's take a look at this stance from the evidence.

To save time, we are going to break this argument down to a couple simple concepts in the greater thing.  First, it is important to note that fossils are all intermediaries. Every species is intermediary.  DNA supports this also (evidence isn't evidence without other evidence to verify, mind).  If we only had fossil evidence, then the idea that every species is unique would also hold water.  We have not only fossil evidence, but also DNA evidence, and similarly we only find given species within various strata of rock that have consistent radioactive timers encasing similar creatures.  One single fossil too far back would be enough to make us see that the other view could require more evaluation.  As yet, it hasn't been found.

So, you ask, where is the testable part of this?  Well, that is the important thing, and the burden of proof is mine. Here we go.

You, me, or anyone can go and start digging up (within reason: please don't go breaking laws, and be safe) the ground and see what fossils we can find.  We can get a Geiger counter any test the radioactive content of the rocks.  We can borrow a mass spectrometer and determine what elements are in it for the decay and it's half life.  We can do the maths on our own to determine our method are good.  We can view other, carefully recorded things, which are verified by more than one observer. 

I think we can see why religious books don't meet this criteria, but in the interest of being thorough, let's analyse the antecedent.  Let's say god really did create each kind of 'animal and plant' in existence.  Let's even skip some of the simpler aspects and jump to Noah.  Noah supposedly saved one of each gender of each type of thing.  Let's even forget about the species of bacteria and flies we can make in labs in a matter of a lifetime, or the different breeds of dog that didn't exist 200 years ago and will likely be species in another 200 or so.  Now let's analyze this through the bible.

One of each kind of animal is A LOT of animals.  It is considerably fewer if we only count the animals Noah would have known about, living essentially in a desert.  But alas, we have indirect evidence that Noah has literally a viable copy of at least every single animal that exist today, plus the ones we know have gone extinct even in our lifetime.  It is important to note that Noah only saved land animals, and that a dove basically found a tree god popped into existence on a fertile plot of land good popped into existence at the 'end' of the worldwide flood. 

Anyway.  My name isn't Randall Munroe, but I am gonna take a shot at a what-if.
What if Noah really did take one of each animalHow big would the ark have to be?  What other interesting things does this tell us?

The first thing is calculating how many animals exist today.  Since I am writing this from my phone, I'm going to use Munroe's style of estimation and leave the math as an exercise to the reader (see if my evidence adds up with your evidence!  Hahaha!  Math jokes!) or the professionals.

Let's look first at the zoos of the world.  Most zoos don't even have 1% of all species (kinds?) in the world, let alone even a representative for each kind of animal (species, genus, family, phylum, who knows.  Kinds are a nice device, eh?).  So we need a boat that can handle, let's say, every current species bigger than a gnat.  And it had to fit all in a boat 500 cubits or so long, among other dimensions.

There are at least two species of elephant.  There are at least ten species of big cat.  There are thousands of marsupials (kangaroos to kookaburra and things in between).  There are likely at least as many species of lizard and mammal and insect and arachnid and crustacean ( not all crustaceans live in the water, and many would die if the world were inundated for over a month.). So let's pretend there's only ten major families of animal.  Let's define them too, since this is science and all.

Mammals, arachnids, crustaceans, marsupials, avians (which, admittedly, fall into most of the others), lizards, reptiles, insects, and some others that are primarily not land dwellers.  Let's say, just to simplify, there's at least a thousand things in each.  So we need room for at least five thousand unique pairs of animals, plus a family of humans, enough rations for a family of at least 20 people (remember, the bible probably omitted lots of women that Noah and his brood would have had) to live for an indefinite period in a time before preserving food was really a thing at all, let alone other various things we take for granted.  It isn't clear if God simply made every animal immune to hunger, thirst, and lots of other things, or if Noah had to prepare food and stuff for them (he did prepare and plan for months of animal bedding, at the very least), or if the number of species simply dwindled as the carnivores are the herbivores. Let's pretend god magically made every animal on earth tame for very brief period of time, and that every species survived because of that magic manna god used later in some desert.

So we have, let's say, ten thousand pairs of animals on a boat.  500 cubits is definitely not more than about 700 feet.  Let's assume this is a square boat, and let's be generous in Noah's arm length.  Let's say this thing is a cube, rather, three football fields long and the football fields wide.  Let's say it is, quite unrealistically, ten floors.  Noah probably didn't think to make the floors varying height to most efficiently accommodate carrying heights per floor (I don't recall and my phone isn't getting internet here, but I think for some reason it was only three floors or so, and Noah had access to all of them). 

So how many animals can we fit on 90 football fields?  226 per field is approximately what we need, that's 112 of each gender, for just 10,000 animals total.  I think it would be hard to fit the thousand representative mammal species in that area, let alone a pair of every species of mammal.  People don't realize, there are lots of animals in the world.  Primates alone would not fit one of each on a single field.  That's us, chimps, bonobos, baboons, gorillas, true monkeys, orangutans, lemurs, et cetera.  Not let's include dogs, wolves, cats, lions, cheetas, hyenas, gazelle, water buffalo, caribou, elk, gnu...

So, it seems the direct evidence of a very large number of species is indirect evidence against the Noah's Ark hypothesis.
And that, my friends, is why evidence is important.

Part two to follow, perhaps?  INDUBITABLY!