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Aluminum foil (2021)

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Re: Aluminum foil (2021)

#111

Post by buildsjets »

proee wrote: post #2

Im interested in using honeycomb aluminum panels for some projects but curious why its so freaking expensive?

Mostly because it is made in a multistep batch process that requires a few hours in an autoclave to cure the epoxy that bonds the skins to the core. And if you want to make anything but a flat panel you will need a very expensive bond jig tool.

But if you REALLY want spend money like it’s going out of style, try all-welded titanium honeycomb. These guys made a lot of parts for the XB-70 bomber, and the afterburners for Concorde.

https://www.astechep.com/honeycomb

Re: Aluminum foil (2021)

#113

Post by jacobgold »

burnte wrote: post #107
jacobgold wrote: post #56

Earlier quoted context omitted.

You shouldn't use aluminum foil with tomato/lemon/vinegar/brined foods or as "grilling packets" (direct fire/high heat) because of leaching risk. There's no concern with using aluminum in most cases (with dry/non-acidic foods) but leaching is a real problem with acidic/salty/wet/high eat.

There's no risk to leeching, there's no data proving any link at all between Aluminum and Alzheimer's. I was a huge advocate for staying away from Aluminum cooking stuff for a long time and my mother even wound up with Alzheimer's. Simply put, I was wrong, there's no link.

> "There's no risk to leeching, there's no data proving any link at all between Aluminum and Alzheimer's."

EFSA (European Food Safety Authority) says acidic or salty foods can increase aluminum leaching from pans and foil into food: https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/j.efsa....

This review found mixed evidence and a positive meta-analysis signal for aluminum exposure and Alzheimer's: https://www.sciencedirect.com/science/article/pii/S014765132...

It's not that hard to avoid this leaching concern, seems smart to make a basic effort to do so.

Re: Aluminum foil (2021)

#114

Post by Ey7NFZ3P0nzAe »

delichon wrote: post #7

I appreciated the paean to aluminum foil in Project Hail Mary where (spoilers) the hero uses it as bowling pins and to reproduce astrophage to eventually save two worlds. It's right up there in the pantheon of useful things with duct tape.

> A paean or pean is a song or lyric poem expressing triumph or thanksgiving

From https://en.wikipedia.org/wiki/Paean

Re: Aluminum foil (2021)

#115

Post by vessenes »

wgd wrote: post #9
vessenes wrote: post #5

I was enjoying the ADHD hyper focus writing, kind of following along, then: > If we figure that the foil can meaningfully change direction every 20 μm, then we might think of an aluminum-foil machine as being made of “moving parts” on the order of 1000 μm² (50 μm × 20 μm), 1000 “parts” per square millimeter of foil; a roll of kitchen aluminum foil is enough to fabricate some 4 billion “parts”. A bootstrapping compile…

I've read a lot of his other writings so that context might be informing my reading here but it sounds like he's pretty straightforwardly discussing the potential of aluminum foil as a uniform-feedstock-slash-construction-material for a hypothetical self-reproducing microfabricator.

Sure, sure. I feel as if there are a lot of steps between a roll of foil and that micro fabricator, though. Like, how are the aluminum fabricator pieces replicably specified to the fabricator? Or is it more like he could imagine silicon controlling stepper motors moving the aluminum fabricator pieces around?

Perhaps I'm missing some commonly known self replicable micro fabricator design; if so, please <<--- send links.

Re: Aluminum foil (2021)

#116

Post by vessenes »

kragen wrote: post #67
vessenes wrote: post #5

I was enjoying the ADHD hyper focus writing, kind of following along, then: > If we figure that the foil can meaningfully change direction every 20 μm, then we might think of an aluminum-foil machine as being made of “moving parts” on the order of 1000 μm² (50 μm × 20 μm), 1000 “parts” per square millimeter of foil; a roll of kitchen aluminum foil is enough to fabricate some 4 billion “parts”. A bootstrapping compile…

I do not currently have a sketch of a matter compiler, just a rough estimate that most of its parts count would probably be RAM, and that it probably needs several kilobytes of RAM.

Hi there! Thanks for the original post, and this sentence which exists in the same liminal space as the original post.

Tell me more about the matter compiler as you imagine it?

Re: Aluminum foil (2021)

#117

Post by Nifty3929 »

jacobgold wrote: post #113
burnte wrote: post #107

Earlier quoted context omitted.

There's no risk to leeching, there's no data proving any link at all between Aluminum and Alzheimer's. I was a huge advocate for staying away from Aluminum cooking stuff for a long time and my mother even wound up with Alzheimer's. Simply put, I was wrong, there's no link.

> " There's no risk to leeching, there's no data proving any link at all between Aluminum and Alzheimer's. " EFSA (European Food Safety Authority) says acidic or salty foods can increase aluminum leaching from pans and foil into food: https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/j.efsa.... This review found mixed evidence and a positive meta-analysis signal for aluminum exposure and Alzheimer's: https://www.s…

"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. Are they also against chlorine?

Clearly they decided to conduct a study to show just how scary aluminum is, and I have no doubt the succeeded.

Re: Aluminum foil (2021)

#118

Post by wyrdcurt »

ceejayoz wrote: post #36
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.

I've only seen people concerned with it in antiperspirants, where it's a salt. (And to be clear, I think it's BS.) As with NaCl, it's at least possible that the salt and the pure-ish variant aren't quite the same thing.

Probably not complete BS. This is anecdotal, but years of experience has taught me that aluminum-containing antiperspirants cause contact dermatitis for me after extended use.

I was also diagnosed with a nickel allergy by a dermatologist when I was a child. Metal allergies are real.

I wouldn't go so far as to say aluminum is toxic for everyone, but it's certainly something I avoid putting on my skin.

Re: Aluminum foil (2021)

#119

Post by kragen »

vessenes wrote: post #116
kragen wrote: post #67

Earlier quoted context omitted.

I do not currently have a sketch of a matter compiler, just a rough estimate that most of its parts count would probably be RAM, and that it probably needs several kilobytes of RAM.

Hi there! Thanks for the original post, and this sentence which exists in the same liminal space as the original post. Tell me more about the matter compiler as you imagine it?

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 DNA to make a plant grow into the shape of even a chair, much less a bicycle, a lathe, or a computer.

- 3-D printers such as RepRap: they generally can only produce very limited machines without further assembly, with only very limited palettes of materials, falling far short of being able to print a whole printer without human intervention.

- ordinary compilers such as GCC: though they have already had a significant economic impact, they require a feedstock of magnetic disks or erased Flash from which to manufacture their output program, which still leaves their users vulnerable to TSMC and Western Digital. Worse, the output program depends on a CPU to run, leaving the users vulnerable to Intel and Qualcomm.

Re: Aluminum foil (2021)

#120

Post by kragen »

onraglanroad wrote: post #104
mishellaneous wrote: post #89

Earlier quoted context omitted.

i guess in that case the question would be if one should be as worried about the biological effects of PFAS as much as these two other forever chemicals you cite

I think it's a little late to be worrying about Nitrogen in the atmosphere. If it's any consolation I believe it's mostly harmless.

Also true of teflon, aluminum oxide, and Earth as a whole. Perfluorooctanoic acid, by contrast, is not mostly harmless.
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