It's just a bunch of automated drones flying in formation. Trying to calculate their orbits ahead of time in any kind of detail would be a fool's errand, instead we'd just use solar light pressure to steer them as needed (they would be very thin, there's no point to making them thick).
With really thin sails (0.78 g/m^2) they don't even need to orbit, as they can use light pressure to compensate for gravity (what Robert Forward termed a 'statite'). The light they reflect hits other sails on the other side, but this isn't a problem if they are distributed uniformly.
Nobody is making use of this service yet. However, if they were, why would it be ghastly for them to voluntarily trade a small number of days worth of terminal decline for a substantially better quality preservation and thus correspondingly higher chance of revival in the future? To me it sounds like an obvious utilitarian tradeoff, like any reasonable person who was well informed about the situation and averse to dying might choose to make.
I'm not sure why people seem so convinced that MNT is a hard requirement here. To be sure there are some components that require fine micrometer to nanometer level precision, but existing mechanical and/or chemical approaches do work, otherwise we wouldn't have things like computer chips
You can draw fibers, use cantilevers, exploit the wavelength properties of laser light, electromagnetically control the path of ionized materials in a vacuum, use piezoelectric actuators that convert current to angstrom level movements, and so on. Not to mention the many approaches to coating a surface with a very thin layer: vacuum deposition, spin coating, electroplating, etc.
> Aldehydes covalently bond and crosslink the proteins and irreversibly kill all of the fixed cells.
That is the textbook answer, however these bonds are only "irreversible" as a matter of biochemistry. You can actually break any chemical bond by increasing the temperature enough. The problem for our purposes is that this means destroying the structure.
> There is zero hope that this provides a solution to cryopreservation except in the slice it up and look at it under the microscope sense.
The trick to reversing the bond without damaging the structure would be in delivering high enough amounts of energy with high enough precision to have only the intended effects. This may or may not be physically possible. However, to rule out the possibility completely, we would need to consider a wide variety of physical interactions that are well outside the range of biology and wet-solvent chemistry, in addition to the full spectra of potential biomimetic and biological approaches.
Good luck. When you make an imine with an aldehyde the principal mechanism of irreversability is that a stray reductant (available in spades in biochemical settings) takes the imine down to a primary amine. (This is not found in most textbooks, you just have to know that). Now, a primary amine is a relatively stable covalent bond, and getting selective deamination is going to be especially difficult since there's plenty of amines around. Not the least of which is the other side of the lysine that the aldehyde attached to in the first place.
> The bag with the remains of the watches gets carefully pocketed and some of the money goes towards ordering a round of drinks for everybody.
I might have misunderstood this bit (in which case, oops). I see way too many people making the assumption that cryonics is somehow primarily profit motivated. Taking money out of the cryonics trust to "buy drinks" would potentially cost the lives of patients, as the organization must remain stable in addition to the revival being achievable to begin with. The incentive is towards long term savings.
> So, how about my watch, asks one of the people that handed over his watch and his money. "Oh, that's the hard part, I haven't really studied that yet, come back in a few 100 years and I might have your watch again. But I'm getting better at smashing watches, that's for sure."
This analogy doesn't make much sense to me. Cryonics is about trying to prevent something that will inevitably be smashed from being smashed as badly. Saying cryonics is about smashing things is like saying seat belts are about cars crashing into each other.
His criticism bad (as ever), since he assumes all information needed for nervous system function is the same as all information needed to replicate a given nervous system. Most of the information needed for function in any system is generic across similar systems. We are only interested in the information that is specific to the individual.
This technique is useful for general neuroscience purposes, yes. My point was just that it isn't what is critical to preserve for the sake of cryonics.
It's interesting that the comments by cell biologist Len Ornstein in that thread completely omit any mention of high osmolality vitrification, which is what is practiced in cryonics. I get the impression he is not aware of Fahy's approach at all. It probably is not used in his specialty.
HOV is using extremely high concentrations of solutes to reduce the freezing point (a colligative property). That is the only way to vitrify something big like the brain. At least, until some super material is invented that lets us pull out lots of heat really fast. The trouble is that it is toxic to cells to be exposed for very long. With rabbit kidneys and small slices of brain tissue, the exposure time at warm temperatures can be very brief. So with current cryonics we can only make a morphological argument for information theoretic preservation.
With better materials that enable faster cooling, prevent the toxicity mechanisms of the cryoprotectant, and/or block ice formation non-colligatively (certain polymers do this), it is theoretically possible that we could get to a point where the cells are still viable. In that event, it would be like placing the brain in an "off state". You wouldn't be able to resume it again without a body to implant it in, but that's more likely to be on the 200-year radar than nanorepair, so the chances would be improved quite a bit. Also, I suspect more people would sign up for a process that does not involve "killing" their brain cells.
I should also mention that the wood frog is really more a counterexample of vitrification. It forms ice (which they are adapted to tolerate, unlike us), but the interior or the cells remains a slightly more concentrated liquid. It is nowhere near the concentrations used in cryonics, which are high enough to prevent freezing entirely (50-80%). A wood frog cannot survive any temperature below around -5 C.
With really thin sails (0.78 g/m^2) they don't even need to orbit, as they can use light pressure to compensate for gravity (what Robert Forward termed a 'statite'). The light they reflect hits other sails on the other side, but this isn't a problem if they are distributed uniformly.