# Interpreting Observations

The ancients, with a few exceptions, thought the Earth was the centre of the Universe and everything rotated around it, thus giving day and night. Contrary to what many people think, this was not simply stupid; they reasoned that it could not be rotating. An obvious experiment that Aristotle performed was to throw a stone high into the air so that it reached its maximum height directly above. When it dropped, it landed directly underneath it and its path was vertical to the horizontal. Aristotle recognised that up at that height and dropped, if the Earth was rotating the angular momentum from the height should carry it eastwards, but it did not. Aristotle was a clever reasoner, but he was a poor experimenter. He also failed to consider consequences of some of his other reasoning. Thus he knew that the Earth was a sphere, and he knew the size of it and thanks to Eratosthenes this was a fairly accurate value. He had reasoned correctly why that was, which was that matter fell towards the centre. Accordingly, he should also have realised his stone should also fall slightly to the south. (He lived in Greece; if he lived here it would move slightly northwards.) When he failed to notice that he should have realized his technique was insufficiently accurate. What he failed to do was to put numbers onto his reasoning, and this is an error in reasoning we see all the time these days from politicians. As an aside, this is a difficult experiment to do. If you don’t believe me, try it. Exactly where is the point vertically below your drop point? You must not find it by dropping a stone!

He also realised that Earth could not orbit the sun, and there was plenty of evidence to show that it could not. First, there was the background. Put a stick in the ground and walk around it. What you see is the background moves and moves more the bigger the circle radius, and smaller the further away the object is. When Aristarchus proposed the heliocentric theory all he could do was make the rather unconvincing bleat that the stars in the background must be an enormous distance away. As it happens, they are. This illustrates another problem with reasoning – if you assume a statement in the reasoning chain, the value of the reasoning is only as good as the truth of the assumption. A further example was that Aristotle reasoned that if the earth was rotating or orbiting the sun, because air rises, the Universe must be full of air, and therefore we should be afflicted by persistent easterly winds. It is interesting to note that had he lived in the trade wind zone he might have come to the correct conclusion for entirely the wrong reason.

But if he did he would have a further problem because he had shown that Earth could not orbit the sun through another line of reasoning. As was “well known”, heavy things fall faster than light things, and orbiting involves an acceleration towards the centre. Therefore there should be a stream of light things hurling off into space. There isn’t, therefore Earth does not move. Further, you could see the tail of comets. They were moving, which proves the reasoning. Of course it doesn’t because the tail always goes away from the sun, and not behind the motion at least half the time. This was a simple thing to check and it was possible to carry out this checking far more easily than the other failed assumptions. Unfortunately, who bothers to check things that are “well known”? This shows a further aspect: a true proposition has everything that is relevant to it in accord with it. This is the basis of Popper’s falsification concept.

One of the hold-ups involved a rather unusual aspect. If you watch a planet, say Mars, it seems to travel across the background, then slow down, then turn around and go the other way, then eventually return to its previous path. Claudius Ptolemy explained this in terms of epicycles, but it is easily understood in term of both going around the sun provided the outer one is going slower. That is obvious because while Earth takes a year to complete an orbit, it takes Mars over two years to complete a cycle. So we had two theories that both give the correct answer, but one has two assignable constants to explain each observation, while the other relies on dynamical relationships that at the time were not understood. This shows another reasoning flaw: you should not reject a proposition simply because you are ignorant of how it could work.I went into a lot more detail of this in my ebook “Athene’s Prophecy”, where for perfectly good plot reasons a young Roman was ordered to prove Aristotle wrong. The key to settling the argument (as explained in more detail in the following novel, “Legatus Legionis”) is to prove the Earth moves. We can do this with the tides. The part closest to the external source of gravity has the water fall sideways a little towards it; the part furthest has more centrifugal force so it is trying to throw the water away. They may not have understood the mechanics of that, but they did know about the sling. Aristotle could not detect this because the tides where he lived are miniscule but in my ebook I had my Roman with the British invasion and hence had to study the tides to know when to sail. There you can get quite massive tides. If you simply assume the tide is cause by the Moon pulling the water towards it and Earth is stationary there would be only one tide per day; the fact that there are two is conclusive, even if you do not properly understand the mechanics.

# The Price of Inequality

Recently, the United States has had a glut of school shootings, and you may be wondering what that has to do with the title. I am going to suggest, quite a lot, indirectly. It also illustrates society’s inability to reason. There are continual calls for gun control, and while I agree there is a rather bizarre lack of responsibility in the ability to buy guns in the US, I do not think that is particularly relevant to what has happened. When I was a boy, I had access to a 22 calibre rifle that I used to go rabbit shooting (rabbits are a real pest in Australia and New Zealand because there are no controlling predators) and yes, I went out and shot rabbits, as did some of my friends, but nobody even thought about going out and shooting a person, let alone a bunch of school children. Why not? Because we all were looking forward to joining society, and we had ambitions. Not big ambitions, but we saw our future place. Of course it did not turn out as we envisaged, but it never does.

So, what is different now? My guess is that too many of the younger generation do not see a future they want. In the US, they see the rust belt, they see the jobs have gone to Asia. Of course the more capable ones see a future, but my betting is the shooters are the very disgruntled ones that see themselves heading to the bottom of the heap. They see nothing to live for, so their warped thinking says they should take out some others first.

And here I come to inequality. What can a young person aspire to, if they are of the pessimistic style nature? In many places, house costs have risen hopelessly so as to price out such ownership from the below average income earner, and worse, more and more people are becoming below average. That is because all the wealth has rocketed into the hands of a few. They see the elderly coming to the point where they cannot retire because they cannot afford to. It is all very well to say that the elderly like working. Some do, but many have started a decline in their health and can’t. Too many people spend most of their income balancing a debt problem. Now you may say, that is their fault, and to some extent it is, but what sort of society are we if there is no way out for the tolerably useful?

An added problem is that as the general income declines, and governments seem determined to lower taxes on the rich, who, by and large, pay surprisingly little anyway, then we see a decline in social welfare, like healthcare, pensions, and an increase in education costs. And what is bizarre, and shows that in a democracy you cannot go wrong by assuming the general population is mathematically illiterate, we find the poor voting for a tax cut that will save them the odd few dollars a week only to find their costs for social services have risen astronomically. And a further odd thing about this is that governments tell their people that they are making progress by privatising such social requirements. “The private sector does things more efficiently,” the economists say, without bothering to check whether the private sector is actually doing it for any but the rich. If you don’t believe me, check the US drug prices, and compare them with many other countries with a state-run single buyer system. Of course the private sector is more efficient but that is at making money, its only real objective.

So, what we see are a few who are making money in truly gross amounts by taking from the many. By and large they are not adding anything to society. Since when did credit default swaps increase the general well-being? And this is what the young see. Something needs to be done, but they feel helpless. Except for the unfortunate monster with a gun.

# What Does Evidence Prove?

I often hear people say they want evidence-based decision-making, but they then behave in a totally different way. My view is evidence is all observed facts relating to the issue at hand. Only too many people think evidence is that which supports their hypothesis, and that which does not is irrelevant. Thus collecting evidence requires dispassionate thoroughness, while determining what such evidence means requires clear logic. However, not everyone is capable of being truly dispassionate once they have reached a conclusion; they do not like revisiting previous decisions.

Consider the hypothetical statement, John murdered Joe. Joe’s apartment door was open, whereupon another apartment dweller found the body, which had a bullet through his head. Forensics tell you he died of the bullet wound at about 1 am. Joe is dead, which meets the first criterion, and there is no gun left behind. So, was he murdered?

Superficially, suicide can be eliminated, but in principle someone else could have removed the gun, so there are actually two hypotheses consistent with that evidence. The police could test the victim’s hands for gunpowder residue, but suppose they jump to a conclusion and don’t bother? Some innocent could go to jail.

So, what about John? People state that earlier John had a heated argument with Joe in his apartment. John has no alibi; he states he was in bed asleep at the time. They find John’s DNA in the apartment, but apart from Joe’s, nobody else’s. After a lot of questioning, the police find someone who saw a man walking away from the apartment block “early in the morning”. The person looked like John and was wearing a hoodie. John owns a hoodie.

So, what do we have? Strictly speaking, nothing against John. John does not deny the heated argument, and it also explains why his DNA is in the apartment. That no other DNA is there is not necessarily indicative that nobody else was there, but merely that nobody else left enough to be found. Just because you argue does not mean you will murder the other person, and anyone that lives alone is likely to be in bed asleep at 1 am. As for the “identification”, all we have is a man of about John’s height was wearing a hoodie. Such evidence can be consistent with a statement, but it can only prove the statement if it falsifies every other possibility.

Now, a real case. A young couple were at a New Year party near a marina and also present (and relevant to this) were our accused, who was drunk and behaving badly by trying to chat up any female, and a “scruffy man”, who was never identified and was alleged by the police to be the accused. The “evidence” in support of this was somehow they got a scruffy photo of the accused and one person picked this photo out of a photo lineup. He was later to say that the photo indicated the degree of scruffiness but it was not intended as a full identification, and as it happened, this photo did not look particularly like the accused. The two young people were ferried out to a boat at the invitation of scruffy man. The man who ferried them out described the boat as a forty-foot ketch. The couple were never seen again.

The police arrested the accused, and claimed they had been taken to his boat, a twenty-six foot sloop. The accused had been repainting his boat, and the police claimed he was covering up evidence. The accused claimed it was normal maintenance. The witnesses claimed that the water taxi ferrying the victims out left on a given course and gave a time for how long it took to get there. That would put it a minimum of ninety meters away from the sloop. The police maintained there was no ketch, but independently some claimed to have seen it, and their location of it was roughly where this water taxi went. In evidence there was no ketch, the police produced a montage of the whole area, and there was no ketch. The problem then was the various photos were all taken at different times, and all of them well before the party. The police argued the two were locked away in a cabin of the sloop, and there were scratch marks where they had fought to get out. Evidence was that the scratch marks had been there before. Finally, after some time, forensics found two hairs belonging to one of the victims on a blanket taken from the sloop. What do you make of that?

If someone were making deep scratches trying to get out (a futile gesture but that is beside the point) there would be a lot of other DNA there. Ha, the police said, the accused cleaned that up. But if he was good enough to clean up all the DNA from everywhere else, why not get rid of the bedding, because it was almost certain that something would be left behind? In my opinion, the key evidence was where these victims were taken. If you know anything about boats, you know the difference between a sloop and a ketch (one and two masts is one major difference) and the ferryman was a master mariner. Further, if the people who saw the water taxi go out and come back have it going to a different place than the sloop, coupled with the ketch, the police have the wrong boat.