Comment by gav on Dry Ice Cryonics- Preliminary Thoughts · 2015-10-16T00:30:09.139Z · score: 1 (1 votes) · LW · GW

OK, here's the gossip: (again, I'm not a scientist, but I'm pretty sure nothing here is grossly misleading).

Some background: M22 is the formula used by Alcor, and VM-1 is the solution used by Cryonics Institute. Both are designed by professional cryobiologists, and M22 is patented (as well as being extensively used for cryoprotection of tissues in 'regular' labs).

There's some info here: VM1 is extremely stable against ice formation at dry ice temps of -80C. However it's more toxic, and wasn't designed for anything other than cooling down. M22 is less stable at -80C, however it's been incredibly cleverly formulated to minimize toxicity, and increase perfusion. It's also got features (such as ice blockers) which come in most handy during the rewarming process, where a lot of damage can occur for cryopreserving organs, etc.

I heard from the designer, Dr Greg Fahy, that he'd run tests holding M22 at -80`C for a week without ice formation, and he gave the impression that too much longer than that might cause trouble.

So as far as long term storage goes, I'd say LN2 is going to be necessary rather than dry ice. However in the future things like Intermediate Temperature Storage (ITS) might make that even more attractive, by preventing fracturing damage.

As a person living in Australia, if I ever died unexpectedly (without having enough time to relocate to Scottsdale), I'd likely be preserved with M22 and sent via dry ice shipping. My take on it is that I'd rather have M22 (Alcor) than VM1 (CI), since good perfusion is so critical in getting a good vitrification in the first place.

Hope this helps!

Comment by gav on Dry Ice Cryonics- Preliminary Thoughts · 2015-09-30T04:09:00.961Z · score: 1 (1 votes) · LW · GW

Yeah, sorry, I felt bad for not acknowledging that bit.

I guess that sufficiently long patient storage at dry ice temperatures would just result in a super thin (nanoscale) layer of ice forming on basically all the nucleation-inducing surfaces (which could then all potentially grow with rewarming), right?

Hmm.. that's a really good question. Off the top of my head I don't know where the actual amount of ice growth over time can be figured out. I'll keep an eye out for more info.

Trouble is, I think, that (depending on perfusion) at -80'C it's water is well below even a suppressed 'freezing point', but still well above the glass transition temp(approx -130'C). So the solution is strongly supercooled and looking for any excuse to shed energy by growing ice crystals, but still mobile enough to rearrange itself to make that happen.

My gut instinct is that it'd be a problem for ice formation on cooling, not just a future rewarming complication, but I'm not sure.

I'm going to go to the Alcor conference next week, if I have the chance I might pose that question to people there. edit: formatting.

Comment by gav on Dry Ice Cryonics- Preliminary Thoughts · 2015-09-30T00:40:31.276Z · score: 1 (1 votes) · LW · GW

Also just another thing that might be interesting:

Check out 'intermediate temperature storage', the idea of storing at a slightly warmer than liquid nitrogen temps (-130'C as opposed to -196'C) is a good idea in order to avoid any fracturing*. This is right near the glass transition temp, so no nucleation can proceed.

Tricky part is there aren't any practical scalable chemicals that have a handy phase change near -130'C, (in the same way that liquid nitrogen does at -196'C) so any system to keep patients there would have to be engineered as a custom electrically controlled device, rather than a simple vat of liquid.

Not impossible, but adds a lot of compexity. They might end up doing it in a few years by putting a dewar in a dewar, and making a robust heater that will failsafe down to LN2 if there's any problem.

*Personally I'm not concerned with fracturing, it seems like a very information-preserving change compared to everything else.

Comment by gav on Dry Ice Cryonics- Preliminary Thoughts · 2015-09-30T00:22:17.987Z · score: 3 (3 votes) · LW · GW

I'm stuck at work for a while, so this is going to be painfully short, sorry.

The bit you're missing is getting below the glass transition temperature prevents both heterogeneous and homogenous nucleation. Dry ice is still well above the glass transition temperature.

Quickest online result I could find for the relevant graph is here:, in section III. Axis labels are "Cryoprotectant concentration" and "Temperature (*C)"

(Although there's a nicer graph Fig3, p36 in Wolker's "Cryopreservation and Freeze Drying Protocols", which just came out this month. Probably not online as of yet)

At very high cryoprotectant concentration (right hand side of the graph) you can transition from 0C to below the Tg without getting in either danger regions (heterogenous nucleation, and homogeneous nucleation). At moderately high cryoprotectant concentration you can transition vertically from 0C to below Tg and only pass through the heterogeneous nucleation danger region, avoiding the homogeneous nucleation region. You typically do this as quickly as posssible, both CI and Alcor have computer controlled systems to accomplish this. With no cryoprotection, or poor perfusion, you pass through the homogeneous nucleation region and ice formation is impossible to prevent.

A typical cryopreservation of a person would have both well and poorly perfused areas, so getting through even the 'safer' danger region of heterogenous nucleation is something you want to do as quickly as possible to prevent ice crystals forming.

/I'm not a doctor, this is just what I've gathered from looking at the research. Hope this helps :-)

Comment by gav on Wear a Helmet While Driving a Car · 2015-07-31T13:44:43.274Z · score: 11 (11 votes) · LW · GW

Hmm.. wait a tic. Helmets absorb shock if your head hits something. On the motorcycle that's pretty much anything around me. But in the car, what exactly can my head hit?

I drive a recent model vehicle, and there's at least two* airbags around the driver. I can't think of any unprotected objects that my head could strike, that a helmet would help deal with. Plus if I wear a helmet, the added mass my neck supports is going to make it more likely to suffer whiplash, surely?

Not to mention that helmets seem to be designed to stop large accelerations over very short distances (i.e. soft-ish foam a couple of cm thick) whereas airbags are designed to act gently over much longer distances (a pre-perforated membrane that absorbs the blow and deforms over, I'm guessing like 20cm?)

I'm guessing that racing drivers wear helmets because in racing conditions debris is more likely to enter the car, the driver be thrown out of the vehicle, or the car will be deformed/destroyed when struck by another race car at 200km/h. Also the balaclava has a role to mitigating fire/burn risk from fuel spills.

I'm also sign(ing) up for cryonics, and want to make darn sure the lump of tissue between my ears isn't broken, but at the moment I can't see a reason helmets in cars would be a net positive.

*Just checked the web, out of curiosity. I apparently have "Driver and front passenger Advanced Airbag System" and "Driver and front passenger seat-mounted side airbags, driver knee airbag, and front and rear side curtain airbags". So that's 4 airbags that will cover just the driver.

Comment by gav on 2014 iterated prisoner's dilemma tournament results · 2014-09-28T23:50:11.826Z · score: 4 (4 votes) · LW · GW

Dang it, days later and I'm still insanely curious to see how the results would differ if the length of the matches wasn't known by the algorithms. Either by removing the concept of limiting matches, or by ending matches far earlier(not just one or two steps) than they were 'planned' to end.

I've been pondering downloading the code, changing and running it, but my shoulder angels start slapping me at the thought of me neglecting my current projects to (even briefly) learn Haskell.

Just occurred to me that there's a way around this, I can offer a shameless bribe to someone else that already knows what they're doing and has some spare time. :-D

With that in mind, $20USD via paypal to the first person who runs the modified tournament and posts the results as a reply to this comment. If you don't want the cash, I'll donate it to MIRI/a charity of your choice, etc.

Comment by gav on 2014 iterated prisoner's dilemma tournament results · 2014-09-25T01:22:19.310Z · score: 3 (3 votes) · LW · GW

I'm kinda surprised, my naive intuition was that SimHatingTitForTat would force a cooperative win.

Does anyone know if the lack of SimHatingTitForTat getting into the finals is an artifact of the algorithms knowing the length of the rounds? (I.e. they can decide to backstab on the final turn to get an extra point).

Comment by gav on The Great Filter is early, or AI is hard · 2014-09-04T04:20:45.433Z · score: 4 (4 votes) · LW · GW

Tongue in cheek thought that just popped into my head: There is no great filter, and we are actually seeing intelligence everywhere because it turns out dark matter is just a really advanced form of computronium.

Comment by gav on What steep learning curve do you wish you'd climbed sooner? · 2014-09-04T02:29:11.668Z · score: 5 (5 votes) · LW · GW

I have to +1 'Writing essays'.

Too easily overlooked in a technical environment, but it really pays off. Both to assist in consolidating your own ideas, and also in communicating them to others.

Comment by gav on What steep learning curve do you wish you'd climbed sooner? · 2014-09-04T01:57:12.009Z · score: 9 (9 votes) · LW · GW

Linux/Unix & their associated command line stuff. The number of times it's come in handy to be able to SSH into a machine that's way over there and do stuff is immense. Sadly I waited till Uni to learn, and I wonder where I'd be now if I'd internalised these concepts by the age of 15.

Need to log something you've just done? Redirect the output into a file. Boom. No longer do you have to find the bit of software that does everything, you just need programs that do simple stuff you can repurpose*.

Reading FOLDOC a bit to get the history was handy too. Thinking of computers as CPUs attached to teletypewriters, with all that fancy graphics stuff as optional explains a lot of how current software ended up the way it is.

*Totally not advocating mainstream computing for every user end up like this, btw. (Linux still makes me cry on a regular basis) Just that being able to drop to a command line and chain together commands or write scripts is so powerful that it's a game changer.

Comment by gav on Change Contexts to Improve Arguments · 2014-07-09T00:28:10.352Z · score: 1 (1 votes) · LW · GW

I like the writeup and the idea very much. I can think of times when I've used something similar in the past, but the bit about recruiting people to do get milk didn't occur to me at the time.

I'm kinda torn, I see it as a very useful technique to defuse a situation and get people reminded about why they talk to each other in the first place. And of course the actual consequences of having a blazing row, which isn't as apparent when we're separated by keyboards. On the other hand as already pointed out a bunch of other social conventions then come into play. ('Home turf', shyness, social dominance, etc.)

At the very least, it's an important option to have in our toolkit.

Comment by gav on Consider giving an explanation for your deletion this time around. "Harry Yudkowsky and the Methods of Postrationality: Chapter One: Em Dashes Colons and Ellipses, Littérateurs Go Wild" · 2014-07-09T00:10:33.357Z · score: 14 (11 votes) · LW · GW

"There seems to be no good reason for banning the post" Drunken (by author admission) fanfic isn't what people come to LW to read. Multi-layered sarcastic incomprehensible stories that have no discernable point other than mockery aren't helpful.

Sure, there are plenty of sequences that use dialogs, but they are used 1) to make a comprehensible point, and 2) have to show their working and explain the conclusion and why it's applicable. is the place for stuff like the original post.

/For ref, I'm not a mod, just a pleb.

Comment by gav on Harry Yudkowsky and the Methods of Postrationality: Chapter One: Em Dashes Colons and Ellipses, Littérateurs Go Wild · 2014-07-08T22:45:28.108Z · score: 5 (9 votes) · LW · GW

This doesn't really seem useful here. I didn't come to LW isn't to read drunk fanfic (or fanfic-fic), and I doubt most people do either.

If you think I'm being unfair, note that HPMOR isn't posted here, just referenced to it. If you actually want to work on writing as you've claimed, rather than trolling, maybe is the better place.

Comment by gav on Rationality Quotes June 2014 · 2014-07-01T05:37:06.245Z · score: 4 (6 votes) · LW · GW

Three Bayesians walk into a bar. The third one ducks

Comment by gav on Open thread, 3-8 June 2014 · 2014-06-08T01:38:02.019Z · score: 2 (2 votes) · LW · GW

If you're lucky enough to be in a country with preferential voting, there's usually a handful of 3rd parties with various policies (with published preferences so you know where the vote will 'actually' end up). So you'll at least have the opportunity to cast a few bits of information, rather than a single bit.

Obligatory Ken the Voting Dingo comic about how it's not possible to waste your vote: "I'll look into this 'hugs'"

Comment by gav on Examples of Rationality Techniques adopted by the Masses · 2014-06-07T14:49:18.556Z · score: 1 (1 votes) · LW · GW

Perhaps Nigerian scammers? Nowadays everyone knows that Nigerian scammers are likely going to take you for a ride, and what tactics they use. And how much it hurts to get stung by one.

You could use the idea of benevolent Nigerian Princes as the 'known false' idea that everyone can agree on, and segue into the features of it that ring alarm bells (high payoff for sending personal info, undeserved wealth triggering our 'greed' buttons, etc) and the idea that being primed on rationality helps you to not fall for whatever the next version of Nigerian scamming turns out to be.

Comment by gav on Open Thread, May 26 - June 1, 2014 · 2014-05-27T11:53:34.880Z · score: 3 (3 votes) · LW · GW

"desire to impose one's morality on alien intelligences." Actually it wasn't quite universal. The Baby Eaters (for all their obvious flaws) only tried to change other people's minds by debate and discussion. I was a bit disappointed that humanity didn't try and take the alien poetic argument and respond to it. As pointed out, it likely wouldn't have been fruitful given the Baby Eaters neurology is largely built on recycled baby-eating circuitry, but still.

Although of course it could be argued that the reason why we didn't see the Baby Eaters actually impose their morality was they were the least technologically sophisticated of all 3 species.

Comment by gav on [LINK] Sentient Robots Not Possible According To Math Proof · 2014-05-15T04:41:59.510Z · score: 16 (16 votes) · LW · GW

From the paper: "In particular, memory functions must be vastly non-lossy, otherwise retrieving them repeatedly would cause them to gradually decay. " I wonder if they've ever met a human being? That's pretty much how we work. Memories don't so much decay as get influenced slightly every time we remember them. That's one reason why they get witnesses to crimes to write stuff down straight away, rather than waiting till a trial, etc.

Sigh. To go from 'brains are pretty good at storing information' to 'therefore brains must never leak lose data in an information theoretic sense' is so misleading that it makes me wonder if it's deliberate.

They seem to be doing this to build up the argument that a non-lossy consciousness isn't computable. (And therefore, humans are special. ) The irony is that they're trying to make human consciousness special by making it more stereotypically robot-like, by implying it can't lose information.

Comment by gav on Meetup : Sydney Meetup - April · 2014-04-23T01:47:27.320Z · score: 0 (0 votes) · LW · GW

Last meetup there seemed to be a bit of interest in locks and locksport. I'll bring along some simple locks and tools and run a short introduction after the main discussion for anyone that's interested.

Cheers, Gav

Comment by gav on Meetup : Sydney Social Meetup - April (Bridge walk) · 2014-04-10T02:37:44.026Z · score: 0 (0 votes) · LW · GW

Whoops, I should have put a question mark in my comment. I'm pretty sure it's a 5:30pm start, but I'm not the one deciding it.

Comment by gav on Meetup : Sydney Social Meetup - April (Bridge walk) · 2014-04-08T22:45:59.558Z · score: 0 (0 votes) · LW · GW


Just want to confirm it's a 5:30pm start. The text says 5:30, but the 'Where/When' says 6:30.

Cheers, Gavin

Comment by gav on Meetup : Sydney Meetup - March · 2014-03-28T00:36:39.783Z · score: 0 (0 votes) · LW · GW

Very nice meetup. I found the calibration exercises by Tim very useful, thanks for running them.

Ian's phenomena of the 'bouncing LED' display interested me enough that I built a bit of hardware to test whether my hunch of why it occurs was correct. I'll bring it in next time to show :-)

Comment by gav on Meetup : Sydney Meetup: February · 2014-02-26T22:12:30.859Z · score: 1 (1 votes) · LW · GW

Just wanted to say good meetup and I had a great time. Looking forward to the next one!