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Aluminum foil (2021)

dernocua.github.io

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Re: Aluminum foil (2021)

#141

Post by kragen »

vessenes wrote: post #127
kragen wrote: post #119

Earlier quoted context omitted.

You're welcome! It's a pretty broad term, with a lot of possibilities, but generally I mean a machine which, given a design for a machine in the form of digital data, can build a working machine of that design without further human interaction. Some imperfect approximations of the idea already exist: - living things such as bacteria, humans, and plants: DNA is digital, true, but it's an unsolved problem to design the…

I like the idea of the lowest technology hurdle required to build one such device. Any ideas? Seems like we must be there in terms of inventability now. A good project to work on!

Yeah, I do have some ideas: https://dernocua.github.io/topics/digital-fabrication.html https://dernocua.github.io/topics/self-replication.html https://dercuano.github.io/topics/self-replication.html https://derctuo.github.io/topics/self-replication.html https://dercuano.github.io/topics/digital-fabrication.html etc.

Re: Aluminum foil (2021)

#142

Post by Alpha3031 »

rldjbpin wrote: post #126
badc0ffee wrote: post #29

It's non-toxic and food safe, and yet a significant number of people on the internet still act like it's poison that will give you Alzheimer's. I wonder how many of those people touch their lips to the lid of an aluminum beverage can. Or how they might bake a lasagna at home.

how funny things work - from Napoleon serving his special guests on aluminium utensils [1] to everyone taking it for granted, even treating it as if it is toxic! cost and availability somehow has a negative correlation to how we treat something. [1] https://en.wikipedia.org/wiki/History_of_aluminium#Early_ind...

Romans used lead utensils, I don't think that was due to cost.

Re: Aluminum foil (2021)

#143

Post by rldjbpin »

Alpha3031 wrote: post #142
rldjbpin wrote: post #126

Earlier quoted context omitted.

how funny things work - from Napoleon serving his special guests on aluminium utensils [1] to everyone taking it for granted, even treating it as if it is toxic! cost and availability somehow has a negative correlation to how we treat something. [1] https://en.wikipedia.org/wiki/History_of_aluminium#Early_ind...

Romans used lead utensils, I don't think that was due to cost.

we used to believe lead could be turned into gold, and used it in fuel to paint not too long ago.

hindsight 20/20, maybe i will be proven ignorant about aluminium in the future.

Re: Aluminum foil (2021)

#144

Post by vessenes »

kragen wrote: post #141
vessenes wrote: post #127

Earlier quoted context omitted.

I like the idea of the lowest technology hurdle required to build one such device. Any ideas? Seems like we must be there in terms of inventability now. A good project to work on!

Yeah, I do have some ideas: https://dernocua.github.io/topics/digital-fabrication.html https://dernocua.github.io/topics/self-replication.html https://dercuano.github.io/topics/self-replication.html https://derctuo.github.io/topics/self-replication.html https://dercuano.github.io/topics/digital-fabrication.html etc.

Thanks. I have now read all of that, and think I have a rough idea of what’s interesting you. What are you working on right now?

Re: Aluminum foil (2021)

#145

Post by IAmBroom »

AnIrishDuck wrote: post #92
HPsquared wrote: post #76

Earlier quoted context omitted.

Aluminium is usually "good enough" relative to copper on both types of conductivity, and it soundly beats copper in terms of conductivity per unit weight (which is the metric of interest in many applications) and presumably in terms of material cost too. Copper is better if you want minimum physical size, though. (EDIT: Copper does have some durability advantages though which is another reason it's often favoured)

It is indeed the conductor of choice at utility scale. It was even briefly used in place of copper wire in construction [1], though that usage was halted when safety issues emerged (differential expansion when mated with legacy copper pulled apart joints and created major fire hazards) 1. https://en.wikipedia.org/wiki/Aluminum_building_wiring

I thought the problem was primarily galvanic activity between copper and aluminum, not thermal growth. A bit of searching says this is so in environments with any wetting or very high humidity. The increased resistivity of aluminum's oxide layer is also part of it.

Basically: they just don't play well together.

Re: Aluminum foil (2021)

#146

Post by jacobgold »

burnte wrote: post #140
Nifty3929 wrote: post #117

Earlier quoted context omitted.

"Aluminum (Al) is a widespread environmental contaminant " - they lost me right there in the very first sentence. Already using charged, non-neutral language ("contaminant"), giving away their pre-existing bias and forcing me to disregard the rest of their opinion on the matter. Aluminum is no more "environmental contaminant" than any other extremely common basic element in the Earth's crust, like silicon or iron. Ar…

Yeah, it's the third most abundant element on the planet. If that's a contaminant, then so is iron and oxygen and nitrogen. Did you know Dihydrogen Monoxide is found in 100% of cancers?

This is a paper on ecotoxicology and environmental safety, so describing aluminum as an "environmental contaminant" makes sense in this context.

> "Did you know Dihydrogen Monoxide is found in 100% of cancers?"

Did you know humans intentionally consume water because they need it to survive, and do not intentionally consume aluminum?

Re: Aluminum foil (2021)

#147

Post by kragen »

vessenes wrote: post #144
kragen wrote: post #141

Earlier quoted context omitted.

Yeah, I do have some ideas: https://dernocua.github.io/topics/digital-fabrication.html https://dernocua.github.io/topics/self-replication.html https://dercuano.github.io/topics/self-replication.html https://derctuo.github.io/topics/self-replication.html https://dercuano.github.io/topics/digital-fabrication.html etc.

Thanks. I have now read all of that, and think I have a rough idea of what’s interesting you. What are you working on right now?

Your response comment saying "I have now read all of that" was posted 11 hours after I linked you to a bit over 120,000 words of notes on the topic you were asking about (according to 150 * [...document.body.innerText.matchAll(/(\d+)\s+minutes/g)].map(m => Number(m[1])).reduce((a, b) => a + b, 0) on a non-overlapping subset of the topic pages).

Some of that material is a little difficult. How did you manage to read it all so fast? I'd like to hear what you found most interesting.

As for what I'm working on right now, probably seeing the sunrise tomorrow, but see also https://news.ycombinator.com/item?id=48807996

Re: Aluminum foil (2021)

#148

Post by AnIrishDuck »

IAmBroom wrote: post #145
AnIrishDuck wrote: post #92

Earlier quoted context omitted.

It is indeed the conductor of choice at utility scale. It was even briefly used in place of copper wire in construction [1], though that usage was halted when safety issues emerged (differential expansion when mated with legacy copper pulled apart joints and created major fire hazards) 1. https://en.wikipedia.org/wiki/Aluminum_building_wiring

I thought the problem was primarily galvanic activity between copper and aluminum, not thermal growth. A bit of searching says this is so in environments with any wetting or very high humidity. The increased resistivity of aluminum's oxide layer is also part of it. Basically: they just don't play well together.

Yeah that checks out too. I'm basically regurgitating what I was told when working the electronics aisles at a hardware store.

After reading the wiki page more thoroughly, there were just a bunch of different issues. Goes to show what happens when you make a seemingly benign but fundamental change in a system full of parts designed for something different.

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