ED: "But it doesn't work for gravity with linear curvature"

Relativity = gravity is represented by the curvature of spacetime. Curvature is linear, R. The formula treats curvature linearly. As things get closer and curvature spikes, the math just scales at a 1:1 rate

Quadratic gravity = Squares the curvature. Doesn't really change things much when everything is far apart, but heavily changes things when everything is close together.

Pros: prevents infinities and other problems when trying to reconcile quantum theory with relativity ("makes the theory renormalizable"). E.g. you don't want to calculate "if I add up the probabilities of all of these possible routes to some specific event, what are the odds that it happens?" -> "Infinity percent odds". That's... a problem. Renormalization is a trick for electromagnetism that prevents this by letting the infinities cancel out. But it doesn't work with linear curvature - gravitons carry energy, which creates gravity, which carries more energy... it explodes, and renormalization attempts just create new infinities. But it does work with quadratic curvature - it weakens high-energy interactions and allows for convergence.

Cons: Creates "ghosts" (particles with negative energies or negative probabilities, which create their own problems). There's various proposed solutions, but none that's really a "eureka!" moment. Generally along the lines of "they exist but are purely virtual and don't interact", "they exist but they're so massive that they decay before they can interact with the universe", "they don't exist, we're just using the math out of bounds and need a different representation of the same", "If we don't stop at R^2 but also add in R^3, R^4, ... on to infinity, then they go away". Etc.

The theory isn't new, BTW. The idea is from 1918 (just a few years after Einstein's theory of General Relativity was published), and the work that led to the "Pros" above is from 1977.

A bit more about the latter. Beyond organophosphates, the main other alternative is pyrethroids. These are highly toxic to aquatic life, and they're contact poisons to pollinators just landing on the surface (some anti-insect clothing is soaked in pyrethrin for its effect). Also, neonicotinoids are often applied as seed coatings (which are taken up and spread through the plant), which primarily just affect the plant itself. Alternatives are commonly foliar sprays. This means drift to non-target impacts as well, such as in your shelterbelts, private gardens, neighbors' homes, etc. You also have to use far higher total pesticide quantities with foliar sprays instead of systematics, which not only drift, but also wash off, etc. Neonicotinoids can impact floral visitors, with adverse sublethal impacts but e.g. large pyrethroid sprayings can cause massive immediate fatal knockdown events of whole populations of pollinators.

Regrettable substitution is a real thing. We need to factor it in better. And that applies to nanoplastics as well.

So, when we say microplastics, we really mainly mean nanoplastics - the stuff made from, say, drinking hot liquids from low-melting-point plastic containers. And yeah, they very much look like a problem. The strongest evidence is for cardiovascular disease. The 2024 NEJM study for example found that for patients with above-threshold levels of nanoplastics in cartoid artery plaque were 4,5x more likely to suffer from a heart attack. Neurologically, they cross the brain-blood barrier (and quite quickly). A 2023 study found that they cause alpha-synuclein to misfold and clump together, a halmark of Parkinsons and various kinds of dementia. broadly, they're associated with oxidative stress, neuroinflammation, protein aggregation, and neurotransmitter alterations. Oxidative stress is due to cells struggling to break down nanoplastics in them. They're also associated with immunotoxicity, inflammatory bowel disease, and reproductive dysfunction, including elevating inflammatory markers, impairing sperm quality, and modulating the tumor microenvironment. With respect to reproduction, they're also associated with epigenetic dysregulation, which can lead to heritable changes.

And here's one of the things that get me - and let me briefly switch to a different topic before looping back. All over, there's a rush to ban polycarbonate due to concerns over a degradation product (bisphenol-A), because it's (very weakly) estrogenic. But typical effective estrogenic activity from typical levels of bisphenol-A are orders of magnitude lower than that of phytoestrogens in food and supplements; bisphenol-A is just too rare to exert much impact. Phytoestrogens have way better PR than bisphenol-A, and people spend money buying products specifically to consume more of them. Some arguments against bisphenol-A focus on what type of estrogenic activity it can promote (more proliferative activity), but that falls apart given that different phytoestrogens span the whole gamut of types of activation. Earlier research arguing for an association with estrogen-linked cancer seems to have fallen apart in more recent studies. It does seem associated with PCOS, but it's hard to describe it as a causal association, because PCOS is associated with all sorts of things, including diet (which could change the exposure rate vs. non-PCOS populations) and significant hormonal changes (which could change the clearance rate of bisphenol-A vs. non-PCOS populations). In short, bisphenol-A from polycarbonate is not without concern, but the concern level seems like it should be much lower than with nanoplastics.

Why bring this up? Because polycarbonate is a low-nanoplastic-emitting material. It is a quite resilient, heat tolerant plastic, and thus - being much further from its glass transition temperature - is not particularly prone to shedding nanoplastics. By contrast, its replacements - polyethylene, polypropylene, polyethylene terephthate, etc - are highly associated with nanoplastic release, particularly with hot liquids. So by banning polycarbonate, we increase our exposure to nanoplastics, which are much better associated with actual harms. And unlike bisphenol-A, which is rapidly eliminated from the body, nanoplastics persist. You can't get rid of them. If some big harm is discovered with bisphenol-A that suddenly makes the risk picture seem much bigger than with nanoplastics, we can then just stop using it, and any further harm is gone. But we can't do that with nanoplastics.

People seriously need to think more about substitution risks when banning products. The EU in particular is bad about not considering it. Like, banning neonicotinoids and causing their replacement by organophosphates, etc isn't exactly some giant win. Whether it's a benefit to pollinators at all is very much up in the air, while it's almost certain that the substitution is more harmful for mammals such as ourselves (neonicotinoids have very low mammalian toxicity, unlike e.g. organophosphates, which are closely related to nerve agents).

I hate all of this sales pressure BS - that the instant anyone hears your name you have to try to "convert" them to sales - and I literally run a webstore.

It's all so deeply anti-consumer, and I want no part in it.

Chinese vehicles, both EV and ICE, are selling like crazy in every market where they can legally be sold. I've spent some time in Latin America recently and have ridden in several of the various models, and the reality is that they are all quite nice. The Uber drivers driving them invariably think that they got excellent value for their money.

In the United States we don't have access to these inexpensive brands. We can either buy expensive ICE vehicles, or even more expensive EVs where you pay a premium to not burn fossil fuels. In that situation it makes sense to want a vehicle that competes favorably with an ICE vehicle. After all, you can get a perfectly good ICE or hybrid vehicle for less than it would cost to buy a less capable EV.

The equation shifts dramatically when the Chinese vehicle you are looking at (whether it is ICE or EV) is 1/3 to 1/2 the price of a comparable vehicle. If I could get a Chinese EV for $13K I, personally, would be willing to put up with some of its shortcomings. As an example, I like the idea of the American made and designed Slate truck. However, it isn't available until next year at the earliest, and it is likely to cost $30K, very close to what a base model Ford Maverik, Nissan Frontera, or even a Toyota Tacoma currently cost. At that price it doesn't really make sense to purchase the far less capable electric vehicle.

However, if the Slate only cost $15K then it becomes far more interesting. That's the sort of price difference that Chinese brands are currently offering. I could learn to live with a range of 150 miles (that's supposedly the Slate's range, Chinese vehicles typically offer more than that), if it costs half as much as the competition. China is making vehicles that are more than competitive with what we currently have access to in the United States, and the prices are very low. The only thing keeping China from making huge inroads in the U.S. auto market is politics.

Sure there are some people that will never buy a Chinese vehicle, and there are other people that will never buy an EV. That's fine. I remember when the same arguments were made against Japanese (and later Korean) vehicles. If the politicians really thought that no one would be interested in these cars then they wouldn't need to protect us from them with tariffs.

The housing market is definitely another place where things have become ridiculously expensive. Fixing that issue is more difficult. Everyone is in favor of low cost housing, until they are building it in their neighborhood.

On the bright side, there is a ready source of inexpensive vehicles already for sale. The only problem is that, in the U.S. at least, our politicians won't let us buy them.

In the case of both cars and houses the solution is to remove existing barriers to supply. Right now it is impossible to build inexpensive housing in many parts of the country, and so we end up with expensive housing instead. It is likewise impossible to buy the inexpensive vehicles that I believe that consumers actually want.

My current daily driver is a 1996 Honda Civic (the base model with a 5 speed manual transmission, no AC, and manual windows). I say this to say that I really like the idea of the Slate. What I want is a basic electric vehicle without frills, and without extra technology that does nothing but break and drive up the price. The problem with the Slate is that it is not yet available, nor is it likely to be available in any numbers for a couple of years. What's more, there are already more capable Chinese vehicles selling in large quantities throughout the world that are available at a lower price. These vehicles come from companies that have already set up manufacturing and distribution channels, and they are selling vehicles in some of the most challenging markets in the world.

I've done a bit of traveling in Latin America in recent years and the reality is that there are several Chinese brands that are already powerhouses when it comes to actually selling, delivering, and maintaining vehicles. They make very competitive vehicles, and, at least in Latin America you can get these vehicles serviced and repaired ridiculously inexpensively. Uber drivers were quick to point out that their BYD (and other brand) Chinese vehicles weren't Toyotas, but they have invariably stressed that they would buy them again.

If it wasn't for the U.S. tariffs the Slate wouldn't even be a contender, and it isn't likely to be a contender when it is finally available. The only real advantage that it has is that it is comparatively affordable when compared to the other ridiculously overpriced EVs that you can currently purchase in the United States.

It is also worth noting that the projected base price of the Slate keeps going up. The first time I heard about it they were saying that it would cost around $12K with tax incentives. That would have put it under $20K without incentives. These days they say that it should cost less than $30K, but that puts it within spitting distance of the base model Ford Maverik, Nissan Frontier, or Toyota Tacoma, which, quite frankly, are far more capable vehicles, from companies with actual track records.

The reason that Chinese EVs are interesting is that they are essentially 1/3 to 1/2 the price of existing ICE truck models with compelling features and decent build quality. In the parts of the world where politics aren't getting in the way these Chinese vehicles are absolutely dominating. That's what I want.

I have spent some time recently in Latin America, including several countries where Chinese imports are absolutely dominating. The local Uber drivers like their Chinese vehicles. They are quick to point out that they don't measure up to Toyota, but that, for the money, they have been an excellent value. They invariably would buy the vehicle again. Every time I get into a Chinese vehicle I ask the driver what he thinks about it, and the results have been overwhelmingly positive.

I haven't driven any of these vehicles, but as a passenger the various Chinese vehicles look pretty well made. For the price I am definitely interested.

The reality is that the entire U.S. auto industry has been chasing the luxury, and large vehicle segment of the market, and I am not interested in those types of vehicles. I want a vehicle that replaces my current daily driver, a 1996 Honda Civic. I don't want someone else's clapped out SUV. I want an inexpensive basic small electric vehicle. The Nissan Leaf is closest to what I am looking for, but in countries where Chinese imports are allowed to flourish the Leaf isn't even a contender. It is simply outclassed by the Chinese offerings.

Firstly, I see you have this notion that martian rocks must all be igneous.

You're not talking about rock, you're talking about regolith.

Depending on where the regolith is sourced

Regolith is not "sourced", it's blown across the whole planet. It's not simply "whatever the underlying strata is made out of".

But, since we are playing 'name the ignorance' in this exchange, your attestation stat perchlorate is 0.5% liberatable oxygen says 'Say i'm ignorant of basic chemistry without saying i'm ignorant of basic chemistry, and am bad at reading too.' The 0.5% statistic comes from the publication at bottom, and is the proportion of the regolith that is perchlorates.

I am the one who mentioned that regolith is 0.5% perchlorates, not that "perchlorates are 0.5% oxygen". *facepalm*

"Saying we'll get oxygen from the 0,5-1% of a poison in martian regolith, rather than bulk ice or CO2, is..."

For God's sake, learn to fucking read.

Washing the regolith to remove the perchlorate is a requirement for *any* other use of that regolith

Which is why you shouldn't be celebrating its existence. It is a problematic contaminant, not a resource.

As you have rightly pointed out, the water ice on mars is more 'frozen mud'. Cleaning the melt is going to be a necessary first step to using it *regardless*. That means either vacuum distillation, thermal distillation, or reverse osmosis filtration. Again, NOT OPTIONAL. This is necessary equipment that you need to bring, regardless.

And this just to get water, the most basic of offworld resources. And all of that equipment (especially the mining hardware itself) requires maintenance and spare parts, which impose more dependencies. And the TRL for use on Mars is low regardless.

You've gone from talking up the ease of operating on Mars to talking it down, yet your self-righteousness hasn't shifted at all in the process.

RO filtration is the least energy intensive of these.

Except, it isn't. 0,5-1% perchlorates. RO typically removes 90-95% of perchlorates. So you're down to ~500ppm. Human safety levels** are in the low parts per billion. You're five orders of magnitude off. Yes, you can purify water that far - and the more perchlorates, the easier - but you're talking an over millionfold reduction. It is not at all trivial. You're talking first RO to get it down to levels where it won't hinder bacterial growth, then bioreactor bacterial remediation, then filtration, then RO, then ion exchange. This is not some little, simple system.

** Plants can tolerate much more perchlorates than humans, but they also bioaccumulate perchlorates of exposed to them, so you have to reduce the water to low ppb levels.

The end products are clean water and perchlorate contaminated mud, and clean mud, with contaminated water.

Viola! *eyeroll*

And your "plan" for dealing with waste perchlorate doesn't just magically produce pure O2 and NaCl in the real world. First off, molten sodium perchlorate, which is what it becomes before it decomposes, is an extremely corrosive oxidizer. Exactly what are you planning to make the furnace out of, platinum? Secondly, you never get perfect decomposition. Apart from residual perchlorates, you have residual sodium chlorate, which is also corrosive, and is a literal herbicide. And your gas stream will contain contaminant chloride and chlorine dioxide, which, news flash, you don't want to breathe.

There is no way on Earth anyone would ever prefer this to just conducting electrolysis on the water that you've already purified.

1. Fertilizer is made from methane, so that's also stuck there. This is a HUGE problem for countries like India.
2. Poor countries are already switching to 4 day work weeks to save fuel.
3. Iran is letting ships whose balances are settled in Yuan leave. That means the power of the petro-dollar is under serious threat.
4. Countries that can no longer get Iranian oil are now buying non-Iranian oil, which drives the price of ALL oil up. There's speculation that it will hit $200/barrel. That's more than 3x what it was over the last few years. That will affect the price of literally everything. All transportation costs go up, so costs for all goods go up.

At some point, the price will get high enough that some countries won't be able to buy it at all, they'll give up. At that point, some interesting things might happen, since the demand drop-off vs. the price drop off will cause a wobble in the price. People will start looking elsewhere for energy.

Solar and small-battery vehicles (e-bikes, e-scooters) might start taking off even more. You might not be able to buy petrol for your car, but your e-bike charges quickly and can still tow a few hundred pounds worth of stuff. Maybe BEVs adoption will become even MORE popular, since it's one less way you have to directly pay for petrol.

But this war is all con. 100%. Like, Trump didn't even fill up the oil reserves before going to war. China's been buying oil for MONTHS at low rates now, so they're actually the least impacted here, despite the fact that they get a lot of oil from Iran. That means they have zero impetus (not that they had much previously) to do anything about this. This is purely punishment for the USA. Those are expensive weapons being wasted on Iranian targets (in some cases, planes that are actually just paint on the ground). It might be possible for the USA to open up the strait again, but the second they leave, Iran can just close it off again. This might be the most forever of the forever wars, or it might just be an outright defeat for the USA.

This whole thing is such a mess on so many different axes. I didn't even get into how Israel is driving a lot of this, and it's all because Netanyahu is a corrupt warmonger. He's firing in all directions, and he's relying on the USA to protect him.

It wasn't just to maintain value for their corporate properties, it's because they love seeing people in the office, doing their bidding. They'd be able to save so much on capital expenditure if everyone worked from home, but they keep people in the office because they looooooove to see who they're oppressing.

Yeah, there was just fuel rationing and it FUNDAMENTALLY changed the car industry for decades? Big cars went out of style and Japanese econoboxes became a thing because people wanted to spend less on gas?

I get it, you were a KID in the 70s, so you didn't really understand what was going on and what the challenges were. But you could go and read about them now if you want--you're probably north of 50, I think you're ready to learn the truth.

It's worth noting that Nikola wasn't his first scam, either.

YOO-HOO