I’ve seen a look in dogs’ eyes, a quickly vanishing look of amazed contempt, and I am convinced that dogs think humans are nuts.
- John Steinbeck
- John Steinbeck
Wednesday, February 15, 2017
Tuesday, February 14, 2017
Quote of the Day
The question of whether a computer can think is no more interesting than the question of whether a submarine can swim.
- Edsger W. Dijkstra
- Edsger W. Dijkstra
Monday, February 13, 2017
How Life (and Death) Spring From Disorder
There’s a thermodynamic cost to storing information about the past that has no predictive value for the future, Still and colleagues show. To be maximally efficient, a system has to be selective. If it indiscriminately remembers everything that happened, it incurs a large energy cost. On the other hand, if it doesn’t bother storing any information about its environment at all, it will be constantly struggling to cope with the unexpected. “A thermodynamically optimal machine must balance memory against prediction by minimizing its nostalgia — the useless information about the past,’’ said a co-author, David Sivak, now at Simon Fraser University in Burnaby, British Columbia. In short, it must become good at harvesting meaningful information — that which is likely to be useful for future survival.
You’d expect natural selection to favor organisms that use energy efficiently. But even individual biomolecular devices like the pumps and motors in our cells should, in some important way, learn from the past to anticipate the future. To acquire their remarkable efficiency, Still said, these devices must “implicitly construct concise representations of the world they have encountered so far, enabling them to anticipate what’s to come.”
[---]
Entropy maximization has long been thought to be a trait of nonequilibrium systems. But the system in this model obeys a rule that lets it maximize entropy over a fixed time window that stretches into the future. In other words, it has foresight. In effect, the model looks at all the paths the particles could take and compels them to adopt the path that produces the greatest entropy. Crudely speaking, this tends to be the path that keeps open the largest number of options for how the particles might move subsequently.
You might say that the system of particles experiences a kind of urge to preserve freedom of future action, and that this urge guides its behavior at any moment. The researchers who developed the model — Alexander Wissner-Gross at Harvard University and Cameron Freer, a mathematician at the Massachusetts Institute of Technology — call this a “causal entropic force.” In computer simulations of configurations of disk-shaped particles moving around in particular settings, this force creates outcomes that are eerily suggestive of intelligence.
In one case, a large disk was able to “use” a small disk to extract a second small disk from a narrow tube — a process that looked like tool use. Freeing the disk increased the entropy of the system. In another example, two disks in separate compartments synchronized their behavior to pull a larger disk down so that they could interact with it, giving the appearance of social cooperation.
Of course, these simple interacting agents get the benefit of a glimpse into the future. Life, as a general rule, does not. So how relevant is this for biology? That’s not clear, although Wissner-Gross said that he is now working to establish “a practical, biologically plausible, mechanism for causal entropic forces.” In the meantime, he thinks that the approach could have practical spinoffs, offering a shortcut to artificial intelligence. “I predict that a faster way to achieve it will be to discover such behavior first and then work backward from the physical principles and constraints, rather than working forward from particular calculation or prediction techniques,” he said. In other words, first find a system that does what you want it to do and then figure out how it does it.
Aging, too, has conventionally been seen as a trait dictated by evolution. Organisms have a lifespan that creates opportunities to reproduce, the story goes, without inhibiting the survival prospects of offspring by the parents sticking around too long and competing for resources. That seems surely to be part of the story, but Hildegard Meyer-Ortmanns, a physicist at Jacobs University in Bremen, Germany, thinks that ultimately aging is a physical process, not a biological one, governed by the thermodynamics of information.
- More Here
You’d expect natural selection to favor organisms that use energy efficiently. But even individual biomolecular devices like the pumps and motors in our cells should, in some important way, learn from the past to anticipate the future. To acquire their remarkable efficiency, Still said, these devices must “implicitly construct concise representations of the world they have encountered so far, enabling them to anticipate what’s to come.”
[---]
Entropy maximization has long been thought to be a trait of nonequilibrium systems. But the system in this model obeys a rule that lets it maximize entropy over a fixed time window that stretches into the future. In other words, it has foresight. In effect, the model looks at all the paths the particles could take and compels them to adopt the path that produces the greatest entropy. Crudely speaking, this tends to be the path that keeps open the largest number of options for how the particles might move subsequently.
You might say that the system of particles experiences a kind of urge to preserve freedom of future action, and that this urge guides its behavior at any moment. The researchers who developed the model — Alexander Wissner-Gross at Harvard University and Cameron Freer, a mathematician at the Massachusetts Institute of Technology — call this a “causal entropic force.” In computer simulations of configurations of disk-shaped particles moving around in particular settings, this force creates outcomes that are eerily suggestive of intelligence.
In one case, a large disk was able to “use” a small disk to extract a second small disk from a narrow tube — a process that looked like tool use. Freeing the disk increased the entropy of the system. In another example, two disks in separate compartments synchronized their behavior to pull a larger disk down so that they could interact with it, giving the appearance of social cooperation.
Of course, these simple interacting agents get the benefit of a glimpse into the future. Life, as a general rule, does not. So how relevant is this for biology? That’s not clear, although Wissner-Gross said that he is now working to establish “a practical, biologically plausible, mechanism for causal entropic forces.” In the meantime, he thinks that the approach could have practical spinoffs, offering a shortcut to artificial intelligence. “I predict that a faster way to achieve it will be to discover such behavior first and then work backward from the physical principles and constraints, rather than working forward from particular calculation or prediction techniques,” he said. In other words, first find a system that does what you want it to do and then figure out how it does it.
Aging, too, has conventionally been seen as a trait dictated by evolution. Organisms have a lifespan that creates opportunities to reproduce, the story goes, without inhibiting the survival prospects of offspring by the parents sticking around too long and competing for resources. That seems surely to be part of the story, but Hildegard Meyer-Ortmanns, a physicist at Jacobs University in Bremen, Germany, thinks that ultimately aging is a physical process, not a biological one, governed by the thermodynamics of information.
- More Here
Quote of the Day
Some people are content in the midst of deprivation and danger, while others are miserable despite having all the luck in the world. This is not to say that external circumstances do not matter. But it is your mind, rather than circumstances themselves, that determines the quality of your life. Your mind is the basis of everything you experience and of every contribution you make to the lives of others. Given this fact, it makes sense to train it.
- Sam Harris, Waking Up: A Guide to Spirituality Without Religion
- Sam Harris, Waking Up: A Guide to Spirituality Without Religion
Sunday, February 12, 2017
What Makes A Predictive Model Interpretable?
First off, we should ask what exactly we want interpretability for. For some it is a trust issue - but here I prefer to go with solid evaluation. Our evolved brain can easily be tricked into ‘understanding’ a model which in fact is completely wrong. For others it is a matter of transparency - my sense is that for that it might be more useful to simple poke the model as a black box by varying the inputs to get a sense of the sensitivity. Say I ask the model what it would have predicted if I was 10 years older than I actually am. This is not exactly consistent with proper IID sampling theories, but in my opinion a fair test.
On the final holy grail of using a model to understand a domain or even the causal relationships between different variables: many approaches have been developed but most of them involve much more stringent rules on the data generation, variability and observability of all relevant information than is usually possible. What is interesting about the work in the field of observational methods (i.e. TMLE and other double robust estimators) for estimating causal impact: we really do not care much about the interpretability of a model. The causal interpretation is derived from the model predictions, not its structure. In fact, the robustness guarantees arise from at least one of the models to be consistent and unbiased - in other words, less interpretable ...
- Claudia Perlich
On the final holy grail of using a model to understand a domain or even the causal relationships between different variables: many approaches have been developed but most of them involve much more stringent rules on the data generation, variability and observability of all relevant information than is usually possible. What is interesting about the work in the field of observational methods (i.e. TMLE and other double robust estimators) for estimating causal impact: we really do not care much about the interpretability of a model. The causal interpretation is derived from the model predictions, not its structure. In fact, the robustness guarantees arise from at least one of the models to be consistent and unbiased - in other words, less interpretable ...
- Claudia Perlich
Quote of the Day
Most people believe the mind to be a mirror, more or less accurately reflecting the world outside them, not realizing on the contrary that the mind is itself the principal element of creation.
- Rabindranath Tagore
- Rabindranath Tagore
Saturday, February 11, 2017
Wisdom Of The Week
Another striking feature of the campaign against cats is how little attention is given to the benefits they confer on human beings. For most of the time in which they have cohabited with people, cats lived outdoors. It is only relatively recently that they began to live in human households in large numbers. What is it that has allowed them to make this evolutionary step? Ailurophobes will say it is the anthropomorphism of cat lovers, who treat their feline housemates as surrogate human beings. But for many cat lovers, I suspect the opposite is true. What they cherish is not how cats resemble us, but their differences from us. Living with cats opens a window into a world beyond our own and teaches us something important about what it means to be human.
One of the most attractive features of cats is that contentment is their default state. Unlike human beings – particularly of the modern variety – they do not spend their days in laborious pursuit of a fantasy of happiness. They are comfortable with themselves and their lives, and remain in that condition for as long as they are not threatened. When they are not eating or sleeping, they pass the time exploring and playing, never asking for reasons to live. Life itself is enough for them.
[---]
Whereas human beings search for happiness in an ever-increasing plethora of religions and therapies, cats enjoy contentment as their birthright. Why this is so is worth exploring. Cats show no sign of regretting the past or fretting about the future. They live, absorbed in the present moment. It will be said that this is because they cannot envision the past or future. Perhaps so, though their habit of demanding their breakfast at the accustomed hour shows they do have a sense of the passage of time. But cats, unlike people, are not haunted by an anxious sense that time is slipping away. Not thinking of their lives as stories in which they are moving towards some better state, they meet each day as it comes. They do not waste their lives dreading the time when their lives must end. Not fearing death, they enjoy a kind of immortality. All animals have these qualities but they seem particularly pronounced in cats. Of all the animals that have lived closely with human beings, cats must surely be the least influenced by them.
“When I play with my cat,” Montaigne wrote, “how do I know she is not playing with me?” With creatures that can be understood only partly by us, one can only speculate about their inner life. Yet it is tempting to suppose that the secret of feline contentment is that cats have no need to defer to a picture of themselves as they imagine they should be. Certainly they have a sense of dignity: they avoid people who treat them disrespectfully, for instance. Yet cats do not struggle to remake themselves according to any ideal self-image. Not inwardly divided, they are happy to be themselves.
Again, it will be said that this is because they have no moral sense. There are many cases of heroic devotion in which cats have risked pain and death to protect their kittens. But it is true that they cannot be taught moral emotions in the way dogs have been taught to feel shame. Cats are certainly not virtue signallers. Nor – except when it concerns their offspring – are they at all inclined to self-sacrifice. But given that cats, consequently, do not kill other cats or anything else in order to become martyrs to some absurd belief system, that may be no bad thing. There are no feline suicide-warriors.
The moralising philosopher who believed he had persuaded his cat to adopt a meat-free diet only showed how silly philosophers can be. Rather than seek to teach his cat, he would have been wiser to learn from it, as Montaigne did. Living in accord with their nature, cats do not need moral instruction. Dissatisfaction with our natural condition, on the other hand, seems to be natural for human beings. The human animal never ceases to strive for some higher form of life. Cats make no such effort. Without any process of laborious cogitation, these lucid, playful and supremely adaptable creatures already know how to live.
- John Gray, What Cats Can Teach Us About How To Live
One of the most attractive features of cats is that contentment is their default state. Unlike human beings – particularly of the modern variety – they do not spend their days in laborious pursuit of a fantasy of happiness. They are comfortable with themselves and their lives, and remain in that condition for as long as they are not threatened. When they are not eating or sleeping, they pass the time exploring and playing, never asking for reasons to live. Life itself is enough for them.
[---]
Whereas human beings search for happiness in an ever-increasing plethora of religions and therapies, cats enjoy contentment as their birthright. Why this is so is worth exploring. Cats show no sign of regretting the past or fretting about the future. They live, absorbed in the present moment. It will be said that this is because they cannot envision the past or future. Perhaps so, though their habit of demanding their breakfast at the accustomed hour shows they do have a sense of the passage of time. But cats, unlike people, are not haunted by an anxious sense that time is slipping away. Not thinking of their lives as stories in which they are moving towards some better state, they meet each day as it comes. They do not waste their lives dreading the time when their lives must end. Not fearing death, they enjoy a kind of immortality. All animals have these qualities but they seem particularly pronounced in cats. Of all the animals that have lived closely with human beings, cats must surely be the least influenced by them.
“When I play with my cat,” Montaigne wrote, “how do I know she is not playing with me?” With creatures that can be understood only partly by us, one can only speculate about their inner life. Yet it is tempting to suppose that the secret of feline contentment is that cats have no need to defer to a picture of themselves as they imagine they should be. Certainly they have a sense of dignity: they avoid people who treat them disrespectfully, for instance. Yet cats do not struggle to remake themselves according to any ideal self-image. Not inwardly divided, they are happy to be themselves.
Again, it will be said that this is because they have no moral sense. There are many cases of heroic devotion in which cats have risked pain and death to protect their kittens. But it is true that they cannot be taught moral emotions in the way dogs have been taught to feel shame. Cats are certainly not virtue signallers. Nor – except when it concerns their offspring – are they at all inclined to self-sacrifice. But given that cats, consequently, do not kill other cats or anything else in order to become martyrs to some absurd belief system, that may be no bad thing. There are no feline suicide-warriors.
The moralising philosopher who believed he had persuaded his cat to adopt a meat-free diet only showed how silly philosophers can be. Rather than seek to teach his cat, he would have been wiser to learn from it, as Montaigne did. Living in accord with their nature, cats do not need moral instruction. Dissatisfaction with our natural condition, on the other hand, seems to be natural for human beings. The human animal never ceases to strive for some higher form of life. Cats make no such effort. Without any process of laborious cogitation, these lucid, playful and supremely adaptable creatures already know how to live.
- John Gray, What Cats Can Teach Us About How To Live
Quote of the Day
Stand up to hypocrisy. If you don't, the hypocrites will teach. Stand up to ignorance, because if you don't, the ignorant will run free to spread ignorance like a disease. Stand up for truth. If you don't, then there is no truth to your existence. If you don't stand up for all that is right, then understand that you are part of the reason why there is so much wrong in the world.
- Suzy Kassem, Rise Up and Salute the Sun: The Writings of Suzy Kassem
- Suzy Kassem, Rise Up and Salute the Sun: The Writings of Suzy Kassem
Friday, February 10, 2017
Quote of the Day
After they had accustomed themselves at Rome to the spectacles of the slaughter of animals, they proceeded to those of the slaughter of men, to the gladiators.
- Michel de Montaigne
- Michel de Montaigne
Thursday, February 9, 2017
Quote of the Day
Do not spoil what you have by desiring what you have not; remember that what you now have was once among the things you only hoped for.
- Epicurus
- Epicurus
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