Quirrelmort is vulnerable to acausal sex
Dolores1984
Karma: 809
sex is not the territory
Less Wrong is not a cult, so long as our meetups don’t include a Matrioshka brain.
I’m an aspiring human
“politics is isomorpic to politics” is obviusly false
In the new version of Newcomb’s problem, you have to choose between a box containing sex and a box containing the coherent extrapolated volition of Pinkie Pie
On another note, I think this story grossly underestimates the number of people who would have philosophical problems with uploading. As far me, I’d be harvesting their technology to build my own upload chair and FAI (which didn’t maximize ponies), to get the hell out of the earth’s pony cone as quickly as possible. But lots of people would pull out the tired ‘but it wouldn’t really be you’ complaint. I’m sure the AI could surmount it, but you ought to show it doing so.
That’s fair. In my case, I think I’ve decided that, so long as we’re all going to be bad people, and value some human life much more than others, I’d rather care a lot about a few people than a little about a lot of people, and calibrate my charitable giving accordingly. It does not seem, in particular, less morally defensible, and it’s certainly more along the lines of what humans were built to do. To that end, I adopted a shelter cat who was about to be put down. My views may change slightly, however, when I am less thoroughly and completely broke.
Read the linked article.
The diameter of the average RBC is ~7.7μ, about 1μ larger than the diameter of the average brain capillary. In order for RBCs to pass through capillaries it is necessary for them to deform (and in so doing place the maximum amount of surface area in contact with the vascular endothelium to facilitate gas exchange). RBC deformability is critically dependent upon RBC intracellular adenosine triphosphate (ATP) concentration being adequate. With periods of ischemia of ~ 7 minutes, RBCs become depleted of ATP and become rigid, making passage through brain capillaries more difficult (higher arterial pressure required) or impossible.
In-house research conducted by the author has demonstrated that the cerebral microcirculation remains profoundly compromised for 30-60 minutes following reperfusion, even when circulation is restored using cardiopulmonary bypass. Brain parencymal and endothelial cell swelling, as well as changes in the zeta potential of the red blood cells, may all be contributing to the extensive blood sludging and microvascular stasis observed after reperfusion following 10 minutes of global normothermic ischemia in the laboratory.
By ‘some time’ I mean on the order of a few hours. This is drawn from a few things, notably people who have recovered from medical death under cold conditions after multiple hours, and the relatively recent discovery that most of the numbers originally thrown around for irreversible brain damage (three to five minutes) are actually due to cell suicide when the patient is too rapidly reoxygenated, and many brain cells may remain viable for several hours. Additionally, the synapses, which are our primary point of concern in cryonics, are less volatile than the oxygen metabolism of the cell proper, which are likely to be the first thing to go.
On the other note, a synthetic oxygen carrier / oxygen-doped particles would certainly be an improvement, if it’s that effective. I wonder if it would be practical to keep a syringe on my person at all time, and wear a bracelet giving instructions for administration.
I guess the goal isn’t to achieve perfect perfusion, but simply to reduce the number of red blood cells in the brain while cooling the brain, to avoid clotting and slow ischemic damage. In the case of an emergency deployment of such a device, you’re already going to experience significant ischemia, one way or another. Though I can see how embolisms could be catastrophic. I don’t know if it would be possible to make such a device simple enough to be operated by an amateur while still being safe to use.
How to Improve Field Cryonics
This is pretty good. I would go through, though, and either reduce, make subtler, or preferably just remove all the parts that would make a LW reader go ‘Hey! I read that blog post.’
Really? Screw that. If my existence makes other people unhappy, I’m entirely fine with that. It’s not any of their business anyway. We can resolve the ethical question the old-fashioned way. They can try to kill me, and I can try to kill them right back.
I suppose that’s fair. I do think that trying to abstract away the horror of genocide is probably not conducive to a good analysis, either, but there may be an approach better suited to this that does not invoke as much baggage.
Not strictly. It’s still explicitly genocide with Venusians and Neptunians—it’s just easier to ignore that fact in the abstract. Connecting it to an actual genocide causes people to reference their existing thinking on the subject. Whether or not that existing thinking is applicable is open for debate, but the tactic’s not invalid out of hand.
One millisecond fixation time might be an excessive requirement, but in order to perform an emulation accurate enough to preserve the self, you will probably need much more detail than the network topology and some statistics. Synapses have fine surface features that may well be relevant, and neurons may have relevant internal state stored as DNA methylation patterns, concentrations of various chemical, maybe even protein folding states. Some of these features are probably difficult to preserve and possibly difficult to scan.
The surface details we can read with SEM, and we can observe chemical/protein concentrations through immunostaining and sub-wavelength optical microscopy (SEM and SWOM hybrid is my bet for the technology we wind up using). I don’t think there’s strong evidence for DNA methylation or protein state being used for long-term data storage. If evidence arises, we’ll re-evaluate then. But modern neuron models don’t account for those, and, again, function realistically, so they’re not critical for the computation. The details we’re reading likely wouldn’t have to be simulated outright—they would just alter the shape of the probability distribution your simulation is sampling from. A lot of the fine stuff is so noisy, it isn’t practical to store data in it. The stuff we know is involved we can definitely preserve. As a general rule, if the data is lost within minutes of death, it’s probably also lost during the average workday.
Actually they vitrified 475 micrometre slices of the hippocampus of rat brains. It’s no mystery that small samples can be vitrified without using toxic concentrations of cryoprotectants.
I honestly don’t think cryoprotectant damage is anywhere near the big problem here. I’m sure it does cellular damage, but it seems to leave cell morphology essentially intact, and isn’t reactive enough to really screw up most of the things we know we have to care about, in terms of cell state. Ischemia is a bigger problem, and one of my points of skepticism about non-standby cryonics. Four plus hours at room temperature simply seems too long. That said, as our understanding of cell death improves, we’re starting to notice that most brain death seems to be failure of the cells’ oxygen metabolisms, not failure of synaptic linkings. I’d like to see studies done on exactly how long it takes relevant neural details to begin to break down at room temperature. That said, flatlining cases suggest that there’s some reason to hope for the time being. I’d like to see the science done, in any case.
PZ Meyers has unreasonably high standards for ‘relevant details.’ Demanding one millisecond total fixation time (with every atom being in precisely the same position as it was during life) is totally ridiculous. If you want to study intraneuron cell biology, sure, you need that, but for brain emulation, all you care about is the connection-ism of the network, and the long term statistical biases of particular neurons’ synaptic connections (plus glial traits, naturally), which is (probably) visible from features many orders of magnitude more durable than the kinds of data he’s talking about. Also, his comments about accelerating the speed of the network are kind of bizarrely ignorant, given how smart a guy he clearly is.
The only way the issues he mentions are problematic is if high-detail inter-neuron computing turns out to be necessary AND long-term state dependent, which the evidence suggests against (the blue brain project has produced realistic synchronized firing activity in a simulated neocortical column using relatively simple neuron models).
As far as a reference goes, there’s this study, in which they took a rat’s brain, vitrified it, and examined it at fine detail, demonstrating “good to excellent” preservation of gross cellular anatomy.
It probably gets pattern matched to ‘state-ist hysteria being used to crush industry.’
Or, in some cases, we consider it to be definitely human—just not a person.
Vitrification seems to work pretty well, in terms of preserving relevant details. Observing some of those features is going to require an as-yet-not-fully-understood immunostaining process, but that’s under neuroscience. As far as the scanners go, the resolution is already adequate or near-adequate for most SEM technologies. It’s just a question of adding more beams and developing more automated methods, so the scanning can be more parallel.
If he can unilaterally declare a worst argument, then so can I. I declare the Worst Argument In The World to be Guilt By Association: “If we can apply a word to something, we must judge it the same as we judge more prototypical instances of that word.”
This part happens way too fast.
This thing talks truth.