Open & Welcome Thread – November 2020

I built a thing.

UVC lamps deactivate viruses in the air, but harm skin, eyes, and DNA. So I made a short duct out of cardboard, with a 60W UVC corn bulb in a recessed compartment, and put a fan in it. 

I plan to run it whenever someone other than my wife and I visits my house.

Movable Housing for Scalable Cities

Note that Mortal Engines--that steampunk movie with the mobile, carnivorous cities--was released halfway between the original publishing of this essay and today.

Given the difficulties people have mentioned with moving high-density housing between and through cities, maybe we need small cities on SMTs ?

Interview with Aubrey de Grey, chief science officer of the SENS Research Foundation

These were some great questions. I doubt a few of the answers, however. For example:

My estimate of how far off LEV is with 50% probability started out at 25 years 15 or so years ago, and is now 17 years, so let’s use round numbers and say 20 years. Those estimates have always been explicitly "post-money", though - in other words, when I say the money would make 10 years of difference, I mean that without the money, it would be 30 years. I think $1B is enough to remove that factor of 2-3 that you mentioned in the previous question, i.e. to take it down to around 1, because it would add a digit to our budget for 20 years. That factor is already coming down, and I expect that it will continue to do so as further progress is made at the bench, which is why I average the benefit out to a factor of 1.5 (i.e. 30/20).

Aubrey de Grey admits to drinking four pints of beer a day, and I believe his total ethanol consumption is much higher (via evidence which is strong to me, but not to you). He's 57, and looks older than many in their 70s. The evidence may be ambiguous on the longevity effects of <2 drinks per day, but it's quite clear on 4 or over.

This doesn't seem like the behavior of someone who truly believes, in the sense of constraining his expected experiences, that his remaining expected lifespan is almost exactly the time to LEV. I don't know what the real timeline to LEV is, but Dr. de Grey acts like he believes it's well over 30 years.

Research on repurposing filter products for masks?

The 100% efficacy for a middle filter layer that's had a saltwater + surfactant sprayed onto it sounds really good; but I wonder how tight the filter material has to be, for that level of efficacy. I also wonder how much air resistance the salt coat adds.

A HEPA filter + carbon would be less restrictive if the carbon part were salted than if the HEPA filter itself were salted, but that might not deactivate all of the virus.

What is the impact of varying infectious dose of COVID-19?

If virus exposure mid-illness worsens your symptoms, doesn't that mean being indoors is harmful? it would be far healthier to spend as much time outdoors as possible? Perhaps on a net hammock if you have to lie down, so your face isn't lying on a cloth full of the virus you're exhaling? Surely this effect would be so large that clinical studies would have noticed by now, people recovering much faster when they're not in a hospital room, or in a room at all.

On a gears-level, it seems like illness severity would be heavily dose-dependent until the virus replication rate has outpaced the amount you could reasonably inhale.

If so, if you have a specific event that you're concerned may have exposed you, it might be worthwhile to sleep outside for a few nights, weather permitting.

How many dimensions is inference space? How many duck-sized horses do we need, to have a 2/3 chance of taking those steps? And are they being modeled as duck-sized monkeys with typewriters, or are they closer to a proper mini-Einstein, who is likely to go the correct direction?

Will grocery stores thwart social distancing, and when should I eat my food stockpile?

I live in a hot region, and have a car parked outside. I've been putting non-heat-sensitive packages in there for a day, since interior temperatures should be going above 130F / 55C, and easily killing any viruses.

March 25: Daily Coronavirus Updates

Disinfection guidelines are 70C for 30 minutes. I've read elsewhere that 27C deactivates the virus, but never seen that claim attached to logs per hour. Has anybody seen quantitative data on covid survival rates in human-survivable temperatures at various humidities?

edit: found some stuff for the last SARS: if you go to 100F / 48C *and* 95+% humidity, you will kill 2 log10 in 24 hours. If you lose humidity *or* temperature, you’re back to the baseline of 1 to 0 logs in 24h.

Do 24-hour hand sanitizers actually work?

For the object-level question, Wei Dai linked to this study showing benzalkonium chloride (and a few related chemicals) ineffective against enveloped human coronavirus (although this was one of the common cold variants).

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