So, how old are you anyway? When asked of a person, the question really means "How long ago were you birthed?", but the question has some other interesting elements as well.
The essential 'me' might be considered to be my mind, and thats probably been around since not long after my birth, albeit in a more primitive form. But my mind is always changing. A mind is a river, changing in every instant, and yet recognizable through time.
But my mind is a part of my body; how old is that? Obviously some parts are new, the skin is renewed quite frequently for example, while others are mostly 'original equipment', the brain comes to mind, so to speak. But are those cells really new? The come directly from other cells, leading all the way back to a single cell with my genetic makeup. And even that cell, with the exception of half its instruction set, a fairly small part of its makeup, came from some other cell. So the cells making up my body have a lineage that extends all the way back, presumably, to not only some of the very first cells on Earth (and if you believe in panspermia, possibly even from Mars or another distant body), but to pre-cell formations. Somewhere in the distant past a few organic molecules came together in a configuration that happened to be self-replicating, and from that event an unbroken chain of replications hundreds of millions of years long leads to directly to me.
So how old am I? In a sense, I am new in every instant, and yet I am also hundreds of millions of years old.
Friday, July 22, 2005
Evolve or Die
It amuses me when I run across some peoples ideas about evolution. It seems that many people have some pretty grand ideas about evolution being some kind of progression toward perfection. As if nature 'wants' to cause changes that lead toward more ideal oganisims.
Nature doesn't 'want' anything. It just is. Life is just the stuff that tends to self-replicate and hasn't failed to do so. Yet. Evolution is just the (usually gradual) accumulation of errors in the replication. The errors that don't replicate as well tend to die off. Thats it, nothing grand about it.
Does it happen on other planets? Almost without a doubt. Does it always lead to the complexity we see here on Earth? Hard to say. Probably only in a narrow range of conditions. There is probably some horrendously complicated math that could accurately describe the probability of complex self-replication occuring under given conditions, but its likely beyond our current capacity to grok. Where it occurs, the vast majority of self-replication probably never progresses beyond simple cyclic chemical compounds. And there are probably places at the other end of the spectrum where changes are chaotic, and so complex replicators cannot develop. Somewhere inbetween is where we find ourselves. Just the right amount of energy and materials and time to allow for layer upon layer of anomalous copies to build up into things like ourselves.
Pretty remarkable from my prespective, I'm glad that it happens and that I have the capacity to appreciate it.
Nature doesn't 'want' anything. It just is. Life is just the stuff that tends to self-replicate and hasn't failed to do so. Yet. Evolution is just the (usually gradual) accumulation of errors in the replication. The errors that don't replicate as well tend to die off. Thats it, nothing grand about it.
Does it happen on other planets? Almost without a doubt. Does it always lead to the complexity we see here on Earth? Hard to say. Probably only in a narrow range of conditions. There is probably some horrendously complicated math that could accurately describe the probability of complex self-replication occuring under given conditions, but its likely beyond our current capacity to grok. Where it occurs, the vast majority of self-replication probably never progresses beyond simple cyclic chemical compounds. And there are probably places at the other end of the spectrum where changes are chaotic, and so complex replicators cannot develop. Somewhere inbetween is where we find ourselves. Just the right amount of energy and materials and time to allow for layer upon layer of anomalous copies to build up into things like ourselves.
Pretty remarkable from my prespective, I'm glad that it happens and that I have the capacity to appreciate it.
Monday, July 11, 2005
Mysteries of the Universe
Why do couches have a gap around the front edge? In many years I have not found any use for this gap. Well, ok, I did find one use. When I was about 14 I would come home from school, get a tray and load it up with bowls and utensils, then scarf down two or three bowls of breakfast ceral while rotting my brain in front of the after-school cartoons. Since I was not supposed to be eating all the ceral (it doesn't take long to go through the groceries when you eat 4 or 5 bowls a day), if anyone came home, I could quickly slide the tray, containing all the breakfast supplies, under the edge of the couch, where it would be safely concealed until I could finish it (or I forgot it until the next day, or worse, over the weekend).
But I'm quite sure that this is not the purpose that couch designers had in mind. At least, not in this universe. In my house, the only thing the gap under the couch serves is to suck in every cheerio, M&M, gummy bear, snack wrapper, hot-wheel, board-book, penny, and DVD case that appears in the vicinity. I believe that the gap may actually cause a slight warping of space-time within a radius of about 30 feet. In this way all the cheerios, M&Ms, gummy bears, snack wrappers, hot-wheels, board-books, pennies, and DVD cases that are left in the room gradually make their way toward the couch, no doubt gleeful in their escape from the roving Roomba or toddler, whichever is worse.
But I'm quite sure that this is not the purpose that couch designers had in mind. At least, not in this universe. In my house, the only thing the gap under the couch serves is to suck in every cheerio, M&M, gummy bear, snack wrapper, hot-wheel, board-book, penny, and DVD case that appears in the vicinity. I believe that the gap may actually cause a slight warping of space-time within a radius of about 30 feet. In this way all the cheerios, M&Ms, gummy bears, snack wrappers, hot-wheels, board-books, pennies, and DVD cases that are left in the room gradually make their way toward the couch, no doubt gleeful in their escape from the roving Roomba or toddler, whichever is worse.
Thursday, July 07, 2005
The Mind
When I speak of the mind I refer to the upper level of our consciousness, where we spend most of our awareness. There are lower level functions of our brains involved in perception of the world and synthesis of those perceptions into a mental representation that operate at a level below that of the mind, although both upper and lower level functions operate biologically in similar ways (both are functions of the chemical and electrical (and possibly other) behaviors of neurons). In a normal brain the mind is not aware of these functions, only their effect, which is a consistant, stable and well integrated representation of the world.
The entirety of what we precieve around us, as detected by our senses and reconstructed by the faculties of our brains, is a model of the real world, constructed and contained entirely within our minds. We normally operate within this model as if it were in fact the real world, but it is not. It is a highly filtered and processed view, with many assumptions so deeply ingrained that we no longer notice them. Some of the assumptions are things we learned as infants (i.e., the apparently Newtonian movement of a thrown object), others may be related to the way our brains develop physically (i.e., what kinds of stimuli produce a pleasure response).
We are probably born with most of the mental faculty required to build a mental model of the world around us, but I think that the details of that model are defined only after we gain some control of our senses and, as very small children, begin exploring the world and discovering relationships between objects and events. The innate abilities of our brains assemble our observations and experiences into a model with predictive powers. The accuracy of this model is limited in much the same way our senses are limited. We have difficulty conceiving of infrared or x-rays as 'colors' of light, because we cannot preceive them as such. We find the predictions of Einstein's theory of General Relativity under extreme conditions (the warping of space-time around massive objects for instance) counter-intuitive because our senses are only accurate enough to allow us to intuit a model with Newtonian physics.
It is important to realize that any reasoning we do is from the perspective of our mental model. An 'objective' or omniscent viewpoint, while a useful tool, is not truely objective. It is a model that we use to make predictions about what a hypothetical objective observer would believe. It should be obvious that the model of an objective observer is not really an objective observer, and will not make predictions that are completely consistant with an actual objective observer. Perception is inaccurate, therefore all models of things perceived are to some extent inaccurate, and so predictions made with them are inaccurate. To act otherwise is to deny our basic nature. Any proposition made on behalf of the objective observer must be credible when restated in the context of our own personal viewpoint, for the two are simply different facades upon the same knowledge.
The entirety of what we precieve around us, as detected by our senses and reconstructed by the faculties of our brains, is a model of the real world, constructed and contained entirely within our minds. We normally operate within this model as if it were in fact the real world, but it is not. It is a highly filtered and processed view, with many assumptions so deeply ingrained that we no longer notice them. Some of the assumptions are things we learned as infants (i.e., the apparently Newtonian movement of a thrown object), others may be related to the way our brains develop physically (i.e., what kinds of stimuli produce a pleasure response).
We are probably born with most of the mental faculty required to build a mental model of the world around us, but I think that the details of that model are defined only after we gain some control of our senses and, as very small children, begin exploring the world and discovering relationships between objects and events. The innate abilities of our brains assemble our observations and experiences into a model with predictive powers. The accuracy of this model is limited in much the same way our senses are limited. We have difficulty conceiving of infrared or x-rays as 'colors' of light, because we cannot preceive them as such. We find the predictions of Einstein's theory of General Relativity under extreme conditions (the warping of space-time around massive objects for instance) counter-intuitive because our senses are only accurate enough to allow us to intuit a model with Newtonian physics.
It is important to realize that any reasoning we do is from the perspective of our mental model. An 'objective' or omniscent viewpoint, while a useful tool, is not truely objective. It is a model that we use to make predictions about what a hypothetical objective observer would believe. It should be obvious that the model of an objective observer is not really an objective observer, and will not make predictions that are completely consistant with an actual objective observer. Perception is inaccurate, therefore all models of things perceived are to some extent inaccurate, and so predictions made with them are inaccurate. To act otherwise is to deny our basic nature. Any proposition made on behalf of the objective observer must be credible when restated in the context of our own personal viewpoint, for the two are simply different facades upon the same knowledge.
Wednesday, July 06, 2005
Justified True Belief
In the early 20th century many philosophers believed that knowledge was 'justified true belief':
A person S can consider a proposition P to be knowledge if, and only if:
Smith has a justified true belief that few observers would consider to be knowledge, although it does satisfy the conditions above. A number of modifications of the JTB scheme have been proposed, and yet none have really solved the problem. It remains one of the most important questions of modern philosophy.
The obvious problem with any variation on JTB is the 'T' part. Any evaluation of 'Truth' must be made from the point of few of an omniscent observer. This makes the scheme completely useless for me, as I am clearly not omniscent, and therefore I cannot evaluate the conditions. I could ask someone else who might know, but the problem remains, I have know way of knowing if they are mistaken (or willfully misleading me), or if my preception of their answer is correct.
Likewise, the 'J' part is difficult. Without the 'T', justification isn't absolute, its just 'probable'. So what we call 'knowledge' is reduced to things that I have some good reasons to believe. Clearly the reasons have to themselves have some good supporting reasons.
Circular, or more precisely, interwoven supporting reasons are the only way to avoid an infinite regression of reasons. Since such a network of supporting facts could be internally consistant and yet still be wrong, it is important to compare the system to observed reality. Those places where large areas of the system have no directly observable counterpart in reality should be questioned. Thats not to say one shouldn't make some guesses as to how things might link together, but such conjecture should be considered fiction until it can be supported via experimentation or direct observation.
In practice this is probably what most people actually do. The differences come about in what people consider valid support. For example, someone of faith might consider a particular feeling they experience when praying over a question to be valid, repeatable (more or less) empirical data that supports the idea that prayer is a valid method of gaining knowledge, and there there is an entity that delivers the answers. Someone like myself would consider that to be (exceedingly) weak evidence. It would be just as valid to conjecture that it is a method of making a random decison and feeling good about it.
The mind is, at this point in our science of the mind, too opaque to make strong statements about why we might feel one way or another when meditating/praying on a given question. This does not mean that the technique is not useful. Indeed, having a simple way to gain confidence and happiness without actually doing anything but sitting quietly for a while is a great thing.
A person S can consider a proposition P to be knowledge if, and only if:
- S believes that P is true
- P is true
- S is evidentially justified in believing that P is true
Smith enters a room and seems to see Jones. He immediately forms the justified belief that "Jones is in the room". In fact, Smith did not see Jones, but rather, a lifelike replica. However, as it happens, Jones is in the room, though Smith has not seen him yet.
Smith has a justified true belief that few observers would consider to be knowledge, although it does satisfy the conditions above. A number of modifications of the JTB scheme have been proposed, and yet none have really solved the problem. It remains one of the most important questions of modern philosophy.
The obvious problem with any variation on JTB is the 'T' part. Any evaluation of 'Truth' must be made from the point of few of an omniscent observer. This makes the scheme completely useless for me, as I am clearly not omniscent, and therefore I cannot evaluate the conditions. I could ask someone else who might know, but the problem remains, I have know way of knowing if they are mistaken (or willfully misleading me), or if my preception of their answer is correct.
Likewise, the 'J' part is difficult. Without the 'T', justification isn't absolute, its just 'probable'. So what we call 'knowledge' is reduced to things that I have some good reasons to believe. Clearly the reasons have to themselves have some good supporting reasons.
Circular, or more precisely, interwoven supporting reasons are the only way to avoid an infinite regression of reasons. Since such a network of supporting facts could be internally consistant and yet still be wrong, it is important to compare the system to observed reality. Those places where large areas of the system have no directly observable counterpart in reality should be questioned. Thats not to say one shouldn't make some guesses as to how things might link together, but such conjecture should be considered fiction until it can be supported via experimentation or direct observation.
In practice this is probably what most people actually do. The differences come about in what people consider valid support. For example, someone of faith might consider a particular feeling they experience when praying over a question to be valid, repeatable (more or less) empirical data that supports the idea that prayer is a valid method of gaining knowledge, and there there is an entity that delivers the answers. Someone like myself would consider that to be (exceedingly) weak evidence. It would be just as valid to conjecture that it is a method of making a random decison and feeling good about it.
The mind is, at this point in our science of the mind, too opaque to make strong statements about why we might feel one way or another when meditating/praying on a given question. This does not mean that the technique is not useful. Indeed, having a simple way to gain confidence and happiness without actually doing anything but sitting quietly for a while is a great thing.
Tuesday, July 05, 2005
Well, Duh?
In yet another stunning reversal, experts are now thinking that perhaps sun exposure isn't such a bad thing after all.
Ya think?
You'd figure that after 50,000 years in the sun the human body would have adapted to make sun exposure more useful than damaging.
Next maybe they'll figure out that people who get sunburned at the mere thought of venturing out into the 'real world' without an environmental suit are perhaps not getting the right nutrition.
For all our skill with technology, we sure have a darth of deep knowledge about how living things work.
Ya think?
You'd figure that after 50,000 years in the sun the human body would have adapted to make sun exposure more useful than damaging.
Next maybe they'll figure out that people who get sunburned at the mere thought of venturing out into the 'real world' without an environmental suit are perhaps not getting the right nutrition.
For all our skill with technology, we sure have a darth of deep knowledge about how living things work.
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