Wandsworth Town, 20/1/2013 - Apple iPhone 4S
Grey. White. Small patches of strong colour. Snow makes shapes out of everything. And when did Wandsworth Town ever look picturesque?
Monday, 11 May 2020
Thursday, 7 May 2020
The Raven Paradox
I cannot believe that anyone is still discussing this, but Sabine Hossenfelder did recently, as did UpAndAtom in mid-2019. Both present it as a serious issue for the idea of evidence and hence the scientific method.
The paradox is due to Carl Hempel, one of the many philosophers who circled round Rudolph Carnap and the Vienna School. They loved them some logic, and this really is.
Consider the hypothesis "All ravens are black". Evidence for this would be a black raven. A counter-example would be a white raven. So far so obvious. But "All ravens are black" is logically equivalent to "All non-black things are non-ravens". The evidence for that is a white tennis shoe and a red tomato. So on the principle that two logically equivalent statements should have the same evidence base, white tennis shoes are evidence for "All ravens are black". Which of course they aren't.
Which is supposed to be a paradox.
Which it is only if we stop to admire it for too long.
It isn't a paradox. It's a sign that our idea of what counts as evidence is nuanced enough to distinguish between statements that are equivalent in the predicate calculus. Nothing says that logical equivalence trumps all other forms of equivalence or lays waste to all other distinctions. Unless you're the kind of person who hung out with the guys at Carnap's Bar and Grill.
The Raven Paradox is a useful edge case: a theory of evidence should not fall foul of it.
Notice that to a falsificationist, there is no problem here. Confirmations don't count, only falsifications. White shoes do not refute the raven hypothesis, but falsificationists do not count the number of refutations, as inductivists do count confirmations. One refutation is too many, and a hundred confirmations are too few. (Ahem.) Notice also that the only things that falsify "All non-black things are non-ravens" are also ravens of any non-black colour. So the positive and its contra-positive have the same counter-examples. Just another logical superiority of falsificationism. But I digress.
Another approach is to notice that white shoes also confirm the claim that "All ravens are green", or indeed any other colour. We might say that if a piece of evidence confirms an hypothesis H(black) and also H(green), H(purple), H(puce) and so on, it is in some sense trivial with respect to that set of hypotheses. It's not what we are really looking for, which is that every time we see a raven, it is reassuringly black. This is an attempt to capture the necessary quality of relevance that evidence must have. It is not perfect, but it's a start. I'll leave the lads at Carnap's Bar and Grill to debate the details.
Instead of trying to resolve the paradox, we should ask: how did we get here? What are we assuming that creates the paradox? Is it true? What are the other assumptions we might have in their place? Who says that "equivalent with respect to the predicate calculus" is the relevant equivalence? Why not "equivalent with respect to the legal concept of material relevance"?
Which would send the ravens flying.
The paradox is due to Carl Hempel, one of the many philosophers who circled round Rudolph Carnap and the Vienna School. They loved them some logic, and this really is.
Consider the hypothesis "All ravens are black". Evidence for this would be a black raven. A counter-example would be a white raven. So far so obvious. But "All ravens are black" is logically equivalent to "All non-black things are non-ravens". The evidence for that is a white tennis shoe and a red tomato. So on the principle that two logically equivalent statements should have the same evidence base, white tennis shoes are evidence for "All ravens are black". Which of course they aren't.
Which is supposed to be a paradox.
Which it is only if we stop to admire it for too long.
It isn't a paradox. It's a sign that our idea of what counts as evidence is nuanced enough to distinguish between statements that are equivalent in the predicate calculus. Nothing says that logical equivalence trumps all other forms of equivalence or lays waste to all other distinctions. Unless you're the kind of person who hung out with the guys at Carnap's Bar and Grill.
The Raven Paradox is a useful edge case: a theory of evidence should not fall foul of it.
Notice that to a falsificationist, there is no problem here. Confirmations don't count, only falsifications. White shoes do not refute the raven hypothesis, but falsificationists do not count the number of refutations, as inductivists do count confirmations. One refutation is too many, and a hundred confirmations are too few. (Ahem.) Notice also that the only things that falsify "All non-black things are non-ravens" are also ravens of any non-black colour. So the positive and its contra-positive have the same counter-examples. Just another logical superiority of falsificationism. But I digress.
Another approach is to notice that white shoes also confirm the claim that "All ravens are green", or indeed any other colour. We might say that if a piece of evidence confirms an hypothesis H(black) and also H(green), H(purple), H(puce) and so on, it is in some sense trivial with respect to that set of hypotheses. It's not what we are really looking for, which is that every time we see a raven, it is reassuringly black. This is an attempt to capture the necessary quality of relevance that evidence must have. It is not perfect, but it's a start. I'll leave the lads at Carnap's Bar and Grill to debate the details.
Instead of trying to resolve the paradox, we should ask: how did we get here? What are we assuming that creates the paradox? Is it true? What are the other assumptions we might have in their place? Who says that "equivalent with respect to the predicate calculus" is the relevant equivalence? Why not "equivalent with respect to the legal concept of material relevance"?
Which would send the ravens flying.
Monday, 4 May 2020
Photographs I'm Printing (4)
River Seine, Paris 27/9/2011 - Canon PowerShot A590 IS
Because the rippling water, the shades of the stone walls, the autumn trees, young folk hanging out, and a warm summer evening. There was a heatwave that week.
Thursday, 30 April 2020
It's time for a while that I thought about things in which I do participate
There is one thing I have begun to realise.
How much of my comments and thoughts are about events in which I do not participate.
For some reason, commenting on things happening elsewhere to other people did not feel strange before. Everyone talks about the news.
Then The Quarantine happened. Governments did things that they have never done before, not even in wars, and some of them assumed powers that no-one should be allowed to keep. For a day. What is happening in America now is unbearable to watch. A once-great nation is breaking up before our eyes.
What is happening in the rest of the world is also incomprehensible, if you try to understand it as the rational reaction of governments to a virus. Understand it as the desperate reaction of exhausted politicians to one more pseudo-crisis being exploited by special interest groups, and hyped up by a media driven by sensation and producing anti-government propaganda, and it makes perfect sense. Now they have to back out of it while maintaining the pretence that it really was serious, without panicking a noisy chunk of the population who believe the hype and without alienating all the voters. That's quite an act.
And here I am, participating in the whole farce and I don't want to comment or think about it. Of course I have, because understanding what happened to cause the Quarantine is the single biggest test of an analyst's abilities. Now I have done it(*), while carrying on with the day job, standing in lines to collect my prescriptions, and trying to run a life, and now I'm done with it.
But right now, I have nowhere to go, and even if I did, I'm a little short on motivation.
We can fix that. There are at least another six weeks before my gym is allowed to open, and large companies will continue to be asked to keep their staff at home for at least another five months. So I have plenty of time to experiment with how I live and work at home.
Which is what I am going to think about now. It's time for a while that I thought about things in which I do participate.
(*) When Boris announced the Quarantine, all the academics and public health advisors said to themselves:
Experts. Huh. Look what happened the last time we listened to the experts! We got locked in to our homes for four months for no reason at all. **** the experts.
How much of my comments and thoughts are about events in which I do not participate.
For some reason, commenting on things happening elsewhere to other people did not feel strange before. Everyone talks about the news.
Then The Quarantine happened. Governments did things that they have never done before, not even in wars, and some of them assumed powers that no-one should be allowed to keep. For a day. What is happening in America now is unbearable to watch. A once-great nation is breaking up before our eyes.
What is happening in the rest of the world is also incomprehensible, if you try to understand it as the rational reaction of governments to a virus. Understand it as the desperate reaction of exhausted politicians to one more pseudo-crisis being exploited by special interest groups, and hyped up by a media driven by sensation and producing anti-government propaganda, and it makes perfect sense. Now they have to back out of it while maintaining the pretence that it really was serious, without panicking a noisy chunk of the population who believe the hype and without alienating all the voters. That's quite an act.
And here I am, participating in the whole farce and I don't want to comment or think about it. Of course I have, because understanding what happened to cause the Quarantine is the single biggest test of an analyst's abilities. Now I have done it(*), while carrying on with the day job, standing in lines to collect my prescriptions, and trying to run a life, and now I'm done with it.
But right now, I have nowhere to go, and even if I did, I'm a little short on motivation.
We can fix that. There are at least another six weeks before my gym is allowed to open, and large companies will continue to be asked to keep their staff at home for at least another five months. So I have plenty of time to experiment with how I live and work at home.
Which is what I am going to think about now. It's time for a while that I thought about things in which I do participate.
(*) When Boris announced the Quarantine, all the academics and public health advisors said to themselves:
****, he's actually going to do it. He wasn't supposed to do it. Quarantining healthy people is so dumb even the WHO knows it's dumb. He was supposed not to do it, so that if things went bad, we could all say we advised him to do it, but he wouldn't listen, and look what happened, and how superior are we? Just like we always do. Of course he shouldn't have listened to us.That's what happened. The experts overlooked how hyped-up the media were, and how tired the politicians were after Brexit, and years of appeasing the unappeasable activists. The disaster that has come on our country will not, however, make the media or the experts or the activists one whit more responsible. Repeat after me...
Experts. Huh. Look what happened the last time we listened to the experts! We got locked in to our homes for four months for no reason at all. **** the experts.
Monday, 27 April 2020
Photographs I'm Printing (3)
Chester Canal Basin - 14/6/2010 Sony Eriksson camera phone
What caught me was the smoothness of the water, that bright sunlight in the middle left edge, and the bright reflection at the front of the barge. It just said print me.
Thursday, 23 April 2020
How We Will Exit From Lockdown
I’ve stopped having to do with the news. I’ve stopped reading the speculations and the pontifications of grey public health bureaucrats getting their moment in the limelight, and who know as little about the economy as they do about fuel injection. I am fed up with the media behaving like a propaganda machine for a virus, the NHS and their own hysteria.
The pundits are assuming that the Unwind will be sensible and intended to get us back to earning and spending. It will be nothing of the sort.
The #UnwindFarce will be an exercise in face-saving public-health theatrics. None of it will make sense, and it will be incoherent. It will be there to pretend to maintain the falsehoods that got us here in the first place: that SARS-Cov-2 is a deadly virus that could have swamped the NHS and killed the entire population, and that closing cafes and theatres, forbidding public protests and fining people for sitting in parks was a proportionate response. Everyone will know it is nonsense, everyone will pretend it isn’t.
So we will be living with irritating idiocies for at least the rest of the year, and hearing the voices of public health people threatening another lockdown for the 2020/21 flu season. Because morale.
What the Coronachampions won’t give up is Social Distancing. But the rules will be mind-bogglingly silly. Shops will have limits on the number of people who can be inside, but not lifts in office blocks. Small companies and call centres will be able to return to their premises, but large companies will have to wait until autumn. Children will be able to go to school, but their parents will have to stand six feet apart outside the school gates. Doctors won’t see anyone in their surgeries, and visitors to A&E will have to wear masks and gloves. Six-foot separation at sports stadiums; theatres and cinemas must provide an empty seat to one’s left, right, front and behind; hairdressers and barbers will have to wear gloves and masks. You can have a massage, but she will have to wear gloves. However, buses, tubes and trains will be full, because who is going to enforce it and how? Cafes and restaurants will have to have six feet between tables, but not between two people dining at the same table. Pubs and bars can have so many people per square metre (half a person).
You get the idea. Silly. Obstructive. Intruding. Mask-wearing virtue-signalling twerps walking around and scowling at people who get near them on public transport, or asking in loud voices if you will social distance and not sit next to them on the bus. Randomly-enforced and inconsistent fines, and in place for months and months, until we all start ignoring it.
The Government will spend billions propping up businesses that cannot survive under its ridiculous rules, because everyone will know it’s the Government’s fault. But that won’t make the initial decision wrong. We will be inconvenienced and threatened with more #VirusKidnapping for at least another two years.
And everyone who doesn’t Politically Distance themselves from the whole #UnwindFarce by about July will lose their seat at the next election. Just like Brexit.
The pundits are assuming that the Unwind will be sensible and intended to get us back to earning and spending. It will be nothing of the sort.
The #UnwindFarce will be an exercise in face-saving public-health theatrics. None of it will make sense, and it will be incoherent. It will be there to pretend to maintain the falsehoods that got us here in the first place: that SARS-Cov-2 is a deadly virus that could have swamped the NHS and killed the entire population, and that closing cafes and theatres, forbidding public protests and fining people for sitting in parks was a proportionate response. Everyone will know it is nonsense, everyone will pretend it isn’t.
So we will be living with irritating idiocies for at least the rest of the year, and hearing the voices of public health people threatening another lockdown for the 2020/21 flu season. Because morale.
What the Coronachampions won’t give up is Social Distancing. But the rules will be mind-bogglingly silly. Shops will have limits on the number of people who can be inside, but not lifts in office blocks. Small companies and call centres will be able to return to their premises, but large companies will have to wait until autumn. Children will be able to go to school, but their parents will have to stand six feet apart outside the school gates. Doctors won’t see anyone in their surgeries, and visitors to A&E will have to wear masks and gloves. Six-foot separation at sports stadiums; theatres and cinemas must provide an empty seat to one’s left, right, front and behind; hairdressers and barbers will have to wear gloves and masks. You can have a massage, but she will have to wear gloves. However, buses, tubes and trains will be full, because who is going to enforce it and how? Cafes and restaurants will have to have six feet between tables, but not between two people dining at the same table. Pubs and bars can have so many people per square metre (half a person).
You get the idea. Silly. Obstructive. Intruding. Mask-wearing virtue-signalling twerps walking around and scowling at people who get near them on public transport, or asking in loud voices if you will social distance and not sit next to them on the bus. Randomly-enforced and inconsistent fines, and in place for months and months, until we all start ignoring it.
The Government will spend billions propping up businesses that cannot survive under its ridiculous rules, because everyone will know it’s the Government’s fault. But that won’t make the initial decision wrong. We will be inconvenienced and threatened with more #VirusKidnapping for at least another two years.
And everyone who doesn’t Politically Distance themselves from the whole #UnwindFarce by about July will lose their seat at the next election. Just like Brexit.
Monday, 20 April 2020
How I'm Reacting To Being A #CoronaHostage
I’m not missing the commute. I’m not missing my hectic morning schedule that gets me out of the house fed, shaved and dressed in forty minutes. I’m not missing paying £11.40 a day to travel into London. Nor am I missing paying £3 for snacks or coffee. I’m not missing the Central and Piccadilly lines to my gym. I’m not missing the short evenings at home, where I’m just de-stressing so I can get to bed at 21:30 or earlier. I am not missing the office, about which I have complained enough. I am not missing the 8,000 - 11,000 steps a day. It’s too many when combined with everything else. I am not missing the traffic. I am not missing the crowds of people.
I know some people miss the buzz, but for a long time I’ve just found London crowded and all the people a bit pointless, and I don’t miss that.
It’s been a long time since I went to the cinema. I’ve stopped going to restaurants because the food quality has gone down and the prices have gone up.
I am missing the workouts at the gym. I am really missing convenience shopping - especially for Boots-y things. I miss going to Foyles and Fopp.
My gas and electric bills have gone up from working from home.
Most of all, I like that if anything goes wrong, it’s not my fault, it’s Dominic Raab’s. If I have to stop paying my council tax because I need the money for food, I can tell them to get the money from good ol’ Dominic.
But then, I have a house and a garden and the weather is fine. What it’s like for couples in small flats in Hoxton I have no idea. I’m still employed and my employer has enough money to pay my salary for a couple of months yet.
I am doing some basic bar-bell and body-weight exercises at home. I’ve just taken delivery of a proper gym mat with lots of foam in it. I’m eating better than I do when I’m at work. I wake up about the same time, but I don’t have to rush when I do. I’ve been keeping up with the MUBI’s, which is pleasant. I’ve stopped with the media, which has turned out to be even more pleasant.
So far, to be honest, so good. But then I’m an a-social grumpy old man, and I don’t feel the loss of the kind of socialising I used to do when I was thirty. And it’s been sunny and warm. What’s not to like?
I know some people miss the buzz, but for a long time I’ve just found London crowded and all the people a bit pointless, and I don’t miss that.
It’s been a long time since I went to the cinema. I’ve stopped going to restaurants because the food quality has gone down and the prices have gone up.
I am missing the workouts at the gym. I am really missing convenience shopping - especially for Boots-y things. I miss going to Foyles and Fopp.
My gas and electric bills have gone up from working from home.
Most of all, I like that if anything goes wrong, it’s not my fault, it’s Dominic Raab’s. If I have to stop paying my council tax because I need the money for food, I can tell them to get the money from good ol’ Dominic.
But then, I have a house and a garden and the weather is fine. What it’s like for couples in small flats in Hoxton I have no idea. I’m still employed and my employer has enough money to pay my salary for a couple of months yet.
I am doing some basic bar-bell and body-weight exercises at home. I’ve just taken delivery of a proper gym mat with lots of foam in it. I’m eating better than I do when I’m at work. I wake up about the same time, but I don’t have to rush when I do. I’ve been keeping up with the MUBI’s, which is pleasant. I’ve stopped with the media, which has turned out to be even more pleasant.
So far, to be honest, so good. But then I’m an a-social grumpy old man, and I don’t feel the loss of the kind of socialising I used to do when I was thirty. And it’s been sunny and warm. What’s not to like?
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