edit: https://news.ycombinator.com/item?id=38373137
root cause: https://hn.algolia.com/?q=cloudflare+archive
Not to nitpick too much, but while wood is "technically" a composite material made up of fiber embedded in lignin, I don't think it's very useful to include it under the broad category of composite materials. Engineered woods like plywood and cross-laminated timber definitely are, but it's more useful to classify regular wood as an organic raw material rather than a composite.
The first composite material humans had any experience with was probably silcrete. It's naturally occurring but ancient humans figured out how to strengthen it by heat treating it in a fire (80-160 kYa). The first time humans intentionally made a composite material is adobe/mudbrick (11 kYa), wattle and daub (6 kYa), plywood in Mesopotamia (5.4 kYa), cob (4 kYa), and finally Romans developed something resembling concrete (I dont remember kYa).
Wood was the chief enabler of trees. Trees have to be big, strong, lightweight, and bendable. Homogeneous materials won't work for that application. You need a composite. So evolution invented one.
Even more amazing: Trees 3D print themselves out of carbon dioxide.
Why wouldn't titanium work for that application? (Assume that somehow the plant can move nutrients and fluids around some other way.) Or even steel, as long as it's not solid? Obviously, nature can't produce hollow steel tubes, but lots of metals satisfy your requirement list here.
Carbon dioxide and low-entropy energy in the form of solar light.
Why would defining it as a raw material be "more useful"? Why is defining it as a composite "less useful"?
About 2 kYa, give or take a couple of centuries.
And it was actual concrete, rather than something resembling concrete. In fact, better than the concrete we were making a hundred years ago, and better than most of our concrete fifty years ago.
Roman aqueducts and bridges are still standing 2000 years later. Not sure I'd put money on the same being true of our stuff.
> Modern composites, starting with Bakelite
AFAIK Bakelite is a resin, not a composite.
No mention of fiberglass, which had been used for many decades before carbon fiber went into widespread use.
> composites—which are amalgamations of a variety of fibers, embedded in a variety of plastics
Steel reinforced concrete is a composite and doesn’t fit this definition.
> Because molded Bakelite incorporated fillers to give it strength, it tended to be made in concealing dark colors.[9]
E: not just elastane but performance fabrics from athleisure in general, good moisture/odour/temperature control, easy to maintain etc. Some people like break in into their cotton/denim classics, but performance fabrics tend to not need break in in at all.
There are a lot of "specialty applications" I think, where plant based material is not ideal. Otherwise I agree.
Are we talking far-tech where plants and other biome actors are engineered to produce materials in a particular shape and manner?
For carbon fiber, a quick google reveals that polyacrylonitrile is the most widely used resin. According to google it is not readily biodegradable: https://www.igtpan.com/Ingles/reciclagem_poliacrilonitrila.a....
Compared to, say, what they climbed Everest with originally, yeah, our gear today is lighter, cheaper, more effective, but also more environmentally impactful and much less degradable.
It's all just byproducts of the oil industry. We're a lot more comfortable now, but it didn't come free.
That's what Rush (who perished in the Titan submersible) also thought....
Still, you have a good point: in engineering (and especially safety-critical projects), you can't just throw some composite material in there willy-nilly and expect it to work out great. OceanGate was a great example of some really stupid and reckless engineering.
The BMW i3 had a carbon fiber frame and was still reasonably priced back in 2013, yet no other normal cars seem to have went this way.
Something the article completely sidesteps when talking about metals versus composites :-)
Cost versus steel may well have been a factor as well.
Like yes, for a bunch of structures you can neatly automate it (see most rocket production), but the shapes of (current) cars don't easily offer themselves to similar options. Automation is possible but would probably be finicky and require a lot of space and energy (for the heating).
but someone else please jump in if you know better/more.
Next-to-fucking-impossible-to-recycle composites.
Other than that, good moisture and odor control, comfort/mobility of stretch too much of life upgrade. Also fairly wrinkle/iron free. I'd take convenience over durability anytime.
I will say synthetics haven't been able to replace bed sheets on most of criterias above.
I don't know if it's elastane but I've definitely seen QoL improvements in clothing compared to 35 years ago (back when I was a teenagers).
Underwear are soooo soft. And they fit perfectly. Same for t-shirts. Same for socks.
I don't know what makes some clothes so comfy (and requiring no ironing either btw) but there's "something" that makes lots of clothes simply better nowadays.
And they last too: I'm the kind of person who hates shopping (which drives my wife mad) so when I find something I like, I'll buy three or five of them (which drives my wife even madder). I've got some pieces I have since years and years (that one is nearly divorce reason ;) Sometimes I find a five years old picture and think: "Oh I already had that thing back then!?".
Yeah, many clothes are just simply better now.
That and having breakfast. It's the same almost everyday - unflavored whey + frozen fruits protein shake.
Brain cycles saved by not having to think.
The rolling resistance coefficent of a car tire is about 0.01 and the force grows linearly with mass. Drag is v^2 and the coefficients are more like 0.2 - 0.3 of the frontal area on most EVs.
Weight savings don't offer that much range savings so there isn't much incentive to pull weight out of a design, especially when carbon fibre tub construction is so much more expensive.
BMW made a bet batteries would remain very scarce and expensive, a bet they lost pretty throughly.
And yes, we'll have to wait a while. Though probably not 2000 years - we only have to wait until our concrete starts failing, which might be a lot sooner than that.
In some ways it seems more like a military operation than a sport (in terms of the logistical complexities).
I guess then it's a question of land use (converting ecosystems into rangeland) vs pollution (from fossil fuels and plastics).
https://www.vox.com/future-perfect/24008053/wool-marketing-e...
Would you happen to know where the data for this table comes from? https://platform.vox.com/wp-content/uploads/sites/2/chorus/u...
Vox cites a LCA database but not a particular study or metastudy. I tried to look for it but couldn't find the exact one.
It seems to me like the kind of thing where the numbers could be drastically different depending on where you draw the boundaries (for plastics, does oil extraction and refining count?) and the sorts of impacts you consider (not just CO2E but as you mentioned, biodiversity, water, waste stream, etc.).
I'm inclined to believe the overall point of that post (sheep make a lot of methane, as any ruminant). But I'm not sure that banning wool outright would have the desirable outcome. I don't think cotton can replace wool in many situations, especially in wet outdoor environments. Would replacing it with (new) synthetics, which is the most common substitute, really be a net positive across all the impacts?
I appreciate the information, regardless!
Clothes made of ‘bamboo fiber’ are made of rayon, for example.
Cotton is also normally mercerized [https://en.m.wikipedia.org/wiki/Mercerisation], or treated like Denim, etc.
It’s all made of cellulose at the end of the day.
Edit: I don’t think cotton is the best replacement. I’m no expert, but I think hemp, flax, and tencel are the “best” replacements in terms of sustainability.
Reducing the oxidized metals requires much more energy than reducing non-metals like carbon, nitrogen and sulfur (which is what the living beings do to make their structural materials), and preventing the reduced metals to spontaneously become oxidized again is very difficult.
This is why no living beings have succeeded to use metallic materials before the humans, and the latter have succeeded to do this only after mastering the fire, which is the other thing that the non-human living beings have not succeeded to do.
There exists a second class of stellar systems, where there is more carbon than oxygen, so almost all oxygen remains bound in carbon oxides, while most other elements are present as carbides, instead of oxides, like in the Solar System. These are much more rare than the stellar systems of the Solar System type and in such stellar systems the chemical composition of the planets would be extremely different from the planets of the Solar System. Because there is no detailed information about such a stellar system (due to their distance), there is very little knowledge about whether there would be conditions in such a system for the appearance of life and how could that evolve. If there is any chance for primitive life forms to use metals in their structures, that would happen only in such stellar systems.
The pre-solar grains are microscopic crystals, i.e. particles of dust, which have come to the Solar System as already solid grains of dust, from other stellar systems, typically having been propelled by stellar explosions, e.g. those of supernovae.
Such pre-solar grains have been incorporated in the many small bodies that have been condensed from gases along with the bigger asteroids and planets at the formation of the Solar System.
Some of those small bodies have fallen on Earth as meteorites (the so-called "chondrites"). When such meteorites have been analyzed carefully, pre-solar grains have been recovered. They can usually be easily distinguished from the local objects, by having very different isotopic compositions.
Among the pre-solar grains, there are many that have come from stellar systems of the second kind, with more carbon than oxygen. Such grains, instead of being silicates, i.e. the most frequent minerals in the stellar systems of the Solar type, have chemical compositions that are unusual for the minerals of the planets of the Solar System, like diamond, graphite, silicon carbide or nitride, titanium carbide or nitride, metal grains of either platinum-group metals or iron-group metals, other carbides, nitrides, sulfides, silicides or titanides.
For now, this is the only direct evidence of the second class of stellar systems, beyond the spectroscopic observations of various stars, which provide estimations for the relative abundance of carbon and oxygen in those stellar systems.
While we have some idea about what kind of minerals might be the most abundant in such stellar systems at the time of their initial condensation from gases, I am not aware of any attempt to simulate the possible internal structure for big planets in such stellar systems, in order to determine whether in such planets there could exist some analogs of the volcanism and hydrothermal vents that can provide the energy flux necessary for the appearance of life in the planets of the terrestrial type.
For instance, many living beings, from bacteria to vertebrates make and use magnetite crystals, for sensing the magnetic field of the Earth.
Magnetite contains iron ions and pure iron is a metal. Nevertheless, magnetite is not a metal, but a ionic crystal, i.e. an insulator. Your blood contains iron and your bones contain calcium, but none of that iron or calcium is in metal form, all are oxidized ions.
There are no living beings that have metallic components. There are a few bacteria that are able to reduce to metallic form the metals that are the easiest to reduce, i.e. gold and silver. However those bacteria do not use in any way the metallic gold or silver that is precipitated outside their bodies by their activity. The reducing of gold and silver is just a defense mechanism for those bacteria, because the ions of gold or silver kill bacteria, and their precipitation when they are reduced removes them from the environment.
As I have said almost all metallic elements present close to the surface of the Earth or of any other planet of this type are oxidized, i.e. they are positive ions that are bound in various ionic substances, like oxides or sulfides, and they can be found inside the bodies of the living beings in the same state as outside (unlike carbon, nitrogen and sulfur, which are oxidized outside, but reduced inside the bodies of the living beings).
Only a few metallic elements are found also as native metals, i.e. copper, silver, gold, mercury and the platinum-group metals. Even for these metallic elements, most of them are far more abundant in oxidized forms (like sulfides or arsenides) than in metallic forms. Only gold is more abundant in metallic form than in oxidized forms, like tellurides (and that is due in good part to the fact that tellurium is also a very rare element, otherwise more gold would be found combined than in metallic form; the gold ions are extremely large, so that they cannot combine well with ions smaller than the telluride ion, like the sulfide ion that combines well with the smaller silver ions).
Currently there is an opportunity for an industrious plastic-eating microbe to hitch a ride in every gut on the planet, deciding the winners and losers of the plastiferous period. All that means, though, is that there's a chance such a creature could appear and take advantage, not that it will happen. (Yes I know plastic-eaters have been discovered, but I'm not aware of any having an effect on the fitness of other creatures.)
It overlaps a whole lot with the concept of a dyson trees, but the core problem is that it needs to be able to use the metal in the first place - earth is a metal planet, in the sense that ~10% of the planet is iron, and yet our trees are not steel.
I also can't help but wonder, could trees even use iron if it was plentiful in the upper crust? You need a lot of energy to separate iron oxide into elemental iron. Betting against what evolution can make is usually a bad idea, but that would be a neat trick.
There are a few such facts about the history and the diversity of the world in which we live that deserve to be known by more people.
It's an artful balance that is so rare—especially online—that I think some of us just savor it when we do find it. I actually went through your older comments (sorry) just to keep reading what you had to say...
At most there have been a few novels or movies that have attempted to describe less familiar landscapes, such as those that could be encountered on the satellites of Jupiter or Saturn.
There have been a few SF stories about planets made of some exotic materials, like diamond or some metals or some superheavy elements, but those were complete fantastic stories without any scientific base and the planets described there could not exist anywhere in the known universe.
I am not aware of any novel or movie that has tried to show a completely alien planet, of the kind that could not exist in the Solar System, but which could really exist in other stellar systems. A planet from a stellar system with a high C/O ratio might have rocks made of abrasive carborundum (i.e. silicon carbide), an atmosphere composed of methane, carbon monoxide and carbon dioxide and an ocean containing a mixture of hydrocarbons, like some kind of petroleum.
If there would be life forms there, they could have very significant differences from the life forms that can appear in the stellar systems of the Solar type.
Here on Earth, an essential chemical property for life is the distinction between hydrophobic and hydrophilic substances, i.e. the fact that water and oil do not mix, which enables the existence of the cells of all living beings, which are made of hydrophobic membranes that partition a hydrophilic solvent. Perhaps on a planet with reversed abundances, where hydrocarbons are very abundant and water is scarce, one could have reversed cell structures, with a hydrophobic solvent partitioned by hydrophilic membranes, though it is not clear if such structures can be made stable. In such a place, most metals would be present in easy to reduce compounds, so living beings with metallic skeletons might exist. (Though at least for now, the appearance of life in such stellar systems seems less likely. In the terrestrial kind of planets, the energy flux for the appearance of life has been provided mainly by the free dihydrogen generated by the oxidation of Fe(II) ions to Fe(III) ions by water, in volcanoes and in hydrothermal vents. It is not known whether some equivalent energy source can exist in a place with little water, but abundant hydrocarbons.)
An SF novel or movie with such a subject, about the exploration of a completely unfamiliar world, could be interesting, but this kind of SF novels were written only up to around a half of century ago. Most modern SF novels or movies no longer try to analyze the consequences of intriguing scientific hypotheses, but they choose the lazier way of just transposing traditional fantastic stories into a pseudo-scientific framework.
