Some people use plastic cutting-trays / knives / forks /spoons / cups / jugs, which also are some things to avoid.
I would also avoid all nonstick pans and utensils, as they're lined with PFAS which is worse than plastic, and slowly it will break off into the food. Beware the industry shills on this forum, as they will have you ignore the fact that ingesting PFAS is well known to result in higher blood levels of PFAS.
Fully agree with you, however eating small bits of PFAS from pans seems to be pretty non toxic.
Even in the recent Veritasium video about it they said that unless the chemical was heated to above ~300 degress C if will pass through the human digestive system without causing any harm.
Didnt know that we reached that level of degredation already! :-D
Another example comes to my mind: In lot of European conutries, at "cheese corner/bar" in the supermarket, every time a piece of cheese is cut, they are removing the foil, cutting the cheese, and then re-packing it in new foil after that - and this for every chees bar in every supermarket: How much kilometers does just one branch waste per year?
Yes I just mean the more expensive tea on the shelf. On cheaper SKUs they're trying to cut cost so they use normal tea bags. The plastic sachets were a trend for a couple years but hopefully most brands have switched away.
That study is interesting because they used SEM to image the plastic afterward, and you can see how the plastic surface has literally been torn up on a microscopic level simply by touching hot water.
Plastic has a low-energy surface, which means it doesn't take much energy to tear it apart. Even Brownian motion is enough, which is pretty wild.
> Or is there really a difference in the quality/taste of the expensive ones?
If we are still talking about tea, then of course there are huge differences. And the best tea is not packaged in individual tea bags (also it's not sold in supermarkets unless it's a country with a very high tea culture).
So at the low end you would have tea that is grown with lots of chemicals, plucked by machines or by badly paid workers, industrially processed in high quantities, sold as bulk on international markets. While on the highest end you would have artisanal small-batch tea with no chemicals involved, possibly grown in some special way like the tea bushes shaded from the sun or hundred years old tea trees in forested areas, processed by hand so the leaves are not broken etc... And all of this is reflected in the taste.
And to add - tea is graded at source, and buyers purchase based on grade. So a low quality tea bag will have tea that is objectively worse than a high quality one, while the best tea is never near a bag.
Saying HEPA filters remove "99%" of microplastic is pretty misleading.
Most of the mass in airborne particles is in the larger sizes of visible dust. However these particles will "fall out" before they reach the air purifier.
The best advice isn't "use only HEPA" or (an odd one, from this article) "use filters with multiple stages," it's to have an air purifier where the Clean Air Delivery Rate (CADR) is matched to room size. For filtering large dust you need a lot of air flow, aim for 6-8 Air Changes per Hour (ACH).
Also the CADR on the box is always on the highest fan speed, which is always way too loud for constant use in an occupied room. So ideally you want to size the air purifiers assuming a fan speed generating 45 decibels or less. HouseFresh is an excellent review site that publishes these numbers.
Most people dramatically undersize their air purifiers, or run them on a very low fan setting, and then they throw up their hands and say that air purifiers don't work.
You don't really want to use HEPA either, you want to maximize airflow.
PC fans with low MERV type filter do great since the smaller the particle (I think this effect kicks in below 5 microns) the better it is at filtering it so if it can pass 10 times more air than a hepa filter it's as effective as one while being able to filter more air faster and keeping the particles airbone.
The only downside is that small range of particles where lower merv filters aren't good enough to filter so upwards of 70% of the particles pass through
Agreed. MERV 11-14 can be far more effective than HEPA.
If you need to filter "one and done" (like pumping air into a hospital operating room), that's where you need HEPA. Most home air purifiers mix the clean air back into the same room, so MERV is closer to the ideal sweet spot.
It's also important to buy reputable brands of MERV filter, ideally ones which have a large number of folds (surface area) like the 3M 1900 MPR. In recent testing about half of filter brands scored well below their claimed MERV rating:
That sounds worth knowing; however when I looked MERV up, it seems that it's a rating system, not a type of filter. Could you be more specific abot the kind of filter you mean?
HEPA is typically just one type of filter with True HEPA as an offspring, MERV is a range which allows you to filter exactly what you need at the highest airflow. It really depends on what kind of pollution you have at your home.
If you just have a lot of dust then you want highest airflow possible (around MERV 9-10) if you want to filter things that cause allergies you need to go as high as MERV 14 since MERV 9-10 effectiveness is super low in that specific range.
> Most people dramatically under-size their air purifiers, or run them on a very low fan setting, and then they throw up their hands and just say that air purifiers don't work.
I believe something is better than nothing here. One of the biggest complaints against air filters is noise so maybe a good compromise would be to run them at full speed and full noise for a certain amount of time or something when nobody is in the room?
A false sense of security can be worse than nothing, because it prevents you from seeking out actually effective options.
I too would like such a "shy" air purifier, but manufacturers always seem to go the other way: when occupancy is detected they increase the fan speed.
Best option IMO is just to get an air purifier with a good CADR-to-decibel ratio and then (again) size it correctly. A surprisingly good option is something called the Airfanta 3 Pro, which is basically like those wildfire filter boxes except it uses PC fans.
The way to get air purifiers to really work well is to install them at the air intake, i.e. in the windows, or where the central air intake is, so all incoming air passes through them. I use indoor air purifiers too, but not as a substitute for ones at the intake. Note that tires and diesel fumes are prominent neighborhood sources of harmful particulates.
It is not expensive to run intake fans in the spring and fall seasons when active heating or cooling are not required.
That helps for pollution that comes from outside (traffic, pollen, wood smoke), but most of the microplastics are generated by moving/wearing synthetic textiles inside the home.
Positive pressure systems are great, love 'em, but there's a quantitative mismatch in this case. Above ~1 ACH your HVAC costs will go through the roof (even with heat/humidity recovery), but for effective filtration you need 6-8 ACH to catch the larger dust before your lungs do.
The therm "microplactics" includes particles up to 5mm. And I think the bulk of the material is probably made of these larger particles. But I guess you're less likely to inhale something that large. So while air filters will remove most of the plastic you might inhale, you will still have to clean up most of the mass of microplastics in your house.
That's a good point. The AI slop video is inaccurate, but entertaining.
For comparison, here's the real deal - transformer winding at Virginia Transformer in the US.[1]
That video provides a good sense of why these things take so long to make.
All those wooden parts. All that slowly and carefully hand wound heavy wire. As they point out, if that wire can move at all, as the magnetic fields pushes and pulls on it, the vibration will, over time, wear out the transformer. It's a very fussy job to get the position and tension right, with wire firmly supported against movement in all directions. That's the difference between a lifetime of a few years and many decades.
It's a boring video.
Here's the whole manufacturing process at ETD in the Czech Republic.[2]
This shows roughly the same sequence of steps as the fake video, but it's real.
Big industrial bay with lots of transformers and overhead cranes. Sheets of lamination steel.
Winding. The moving and shipping of the big transformer.
All that is in both the real video and the AI slop.
This is the real video from the manufacturer, and it assumes that if you're watching, you know what you're looking at. There's little narration.
It's a confusing video.
Here's a small open frame transformer.[3] If you've done much electrical or electronics work, you've seen one, and may have replaced or installed one. When you see the big ones being built, the process makes sense. Same concept, with a laminated core, windings, insulation, and lead wires. The big ones have the same key parts, just much bigger. But if you don't know a transformer from a transistor, the manufacturer videos are just wallpaper.
And there's the problem. The AI slop version will give the average viewer a general idea of the process. The accurate videos from manufacturers require more background knowledge to comprehend.
The target audience is different. The manufacturers don't make those videos for the general public.
As far as I can tell, the video itself is 100% fake. A bad fake. I particularly love the part where the worker levitates a large coil of steel with his hands. The narration sounds OK, so just turn off your monitor.
With today's very high orbital launch costs, it's trivially true that the desert is cheaper.
With very low orbital launch costs, it's trivially true that space would become cheaper. Solar panels have no atmosphere/night/seasons and are always pointed at the Sun, no cover glass for hail, no 24h battery either. Radiators are 1/10th the area of PV which is very doable.
The question is, where exactly is the tipping point between those two extremes, and will Starship reach that? Opinions on this naturally bifurcate depending on one's feelings about Elon Musk.
I wouldn't be too worried because SpaceX engineers put a great deal of effort into reflection mitigation, including developing a space-rated mirror able to have an RF signal fire transparently through it.[1] The strategy is to bounce all the sunlight away from Earth, which makes satellites darker than even (hypothetically) covering a satellite in Vantablack.
I don’t want to be foolishly dismissive, but I just don’t see how launch costs could be small enough to compensate for the huge overhead of putting things into space and maintaining things in space as opposed to literally any other place on earth.
I think the burden of proof is on the people who want to tell us that this is economical to show the numbers
Starship becomes “fully and rapidly reusable”, needing little to no refurbishment between launches. Then the lower bound of launch costs is just the expendables (methane, oxygen, nitrogen) which could cost as little as $1M per launch.
SpaceX uses custom silicon (produced by “TeraFab”) that can run at higher temperatures then the radiative cooling requirements goes down significantly and a 100 kW satellite might weight around 1 ton.
Starship should be able to launch at least 100T payload. Assuming they could fit that many, that puts the launch cost per 100 kW at $10,000, which is a rounding error compared to the cost of the chips alone, even if it’s off by a factor of 10.
Obviously a lot needs to go right for this to happen, but it’s not impossible.
Before the cost of flying very heavy shit and dealing with all the problems of operating that shit in space goes to zero, the cost of doing it terrestrially will go to zero. The idea that shooting any amount of payload into space could some how be more economical than just not doing that is completely bonkers and laughable.
It's like people completely forgot that there was 15+ years of connectivity infrastructure build out on earth before Musk did his shittier space version, not the other way around.
Transport doesn't "go to zero." Terrestrial transportation is already fully reusable, so it doesn't have the same cost headroom for improvement vs orbital launch.
Thanks, I really needed this post. I'm saving this for when people inevitably try to re-write history by saying "we didn't need Elon, because did anyone really doubted space-based AI would be the winner?? It was obvious all along because blah blah... <insert 20/20 hindsight>"
I would imagine there are a few different possible options (preferably a settable parameter):
* Intersection. Conceptually the simplest, the chamfers would just be joined by the solid addition of all three fillet surfaces, creating three new sharp corner edges that meet at a single vertex.
* Rolling sphere. Imagine an idealized spherical "thumb" smoothing out caulk. The middle would be joined by a new spherical concave surface, tangent to all three fillets. Also generalizable to convex fillet intersections, smoothing out sharp corners.
* NURBS, with adjustable parameters or even control points, eg when you want a little more "meat" in a corners for strength of a part.
* Flat corners, for chamfers (what do do when N>3 corners meet?)
* What else?
Ideally you might be able set the corner type separately for inside vs outside corners, or on a per-vertex or (in the most granular case) per-incoming-edge basis? Is that crazy?
How do saddle corners[0] behave? Does it just "work out" and (by some miracle) uniquely resolve for all permutations and corner types?
That’s not even the complex part. Most of what you describe is a user interface issue, not a geometric kernel issue.
The hard part of 3 corners fillets is the tolerances. Each of those fillet operations has its own compounding float errors and when they meet, the intersection is so messy that they often do not intersect at all. This breaks almost every downstream algorithm because they depend on point classification to determine whether an arbitrary point is inside the manifold, outside, or sitting on an edge or vertex.
And that description of the problem is just scratching the surface. Three corner filets create a singularity in UV space at the common vertex so even when you find a solution to the tolerance problem you still have to deal with the math breaking down and a combinatorial explosion of special cases, almost each of which has to be experimentally derived.
when i did openscad, i just did a minowski hull with a 4sided bipyramid (aka rotated cube) to get chamfers for my cubes.
bonus: minowski hull with a round pyramid adds chamfers in the vertical and fillets in the horizontal, which is what i want for 3d printing most of the time. additionally it closes small overhangs, and it makes fonts smoother (i.e. fonts don't extrude in a 90degree angle, and get 45degree instead, and print better on vertical faces)
disclaimer: I havent used openscad for about a year and my memory may be fuzzy
edit: i am not saying minowsky hull would directly solve your problem, but maybe the algorithm gives you inspiration to solve your numerical issues
OpenSCAD is mesh based so it's not even in the same universe as a proper brep geometric kernel. Everything is easier when you give up on the math entirely, but that’s not good enough for real world manufacturing and simulation.
All of the major commercial geometric kernels have been working on these problems for thirty years and I’m sorry, but your five minutes experience with a glorified tessellator isn’t going to make progress on long standing computational geometry problems.
>that’s not good enough for real world manufacturing and simulation
Dumb question: why not?? It's working for that guy and his 3D printer apparently, which is "real world" (though one could certainly argue it's not proper "manufacturing").
In theory pi has infinite places, sure . In real-world practice (vs math-lympics) you never need more than 100 digits, and indeed you rarely ever actually need more than 5.
Why doesn't it work to "just" throw more bit-width and more polygons at it? Who out there actually needs more than that (vs who just thinks they do)?
The answer boils down to “floating point math” and “discontinuities”.
> indeed you rarely ever actually need more than 5.
That’s not how math works. With every operation the precision falls, and with floats the errors accumulate. What was five digits quickly becomes 3 digits and now you’ve got three surfaces that are supposed to, but don’t technically intersect because their compounding errors don’t overlap even though the equations that describe them are analytically exact. Modern geometric kernels have 3 to 7 tolerance expansion steps that basically brute force this issue when push comes to shove.
Once you have these discontinuities, a lot of critical math like finite element modeling completely breaks down. The math fundamentally depends on continuous functions. Like I mentioned above, three corner filets create a singularity in parametric space by default, so even the core algorithms that kernels depend on to evaluate surfaces break on a regular basis on basic every-day operations (like a box with smoothed edges - aka almost every enclosure in existence)
> Who out there actually needs more than that (vs who just thinks they do)?
I can’t stress this enough: almost everyone. CAD isn’t one of those fields where you can half ass it. Even the simplest operations are bound to create pathological and degenerate cases that have to be handled, otherwise you have a pile of useless garbage instead of a 3d model.
Slicers deal with meshes, like video game renderers, not boundary representations like CAD kernels. There is effectively zero overlap. Even just tessellation, the step that converts brep to mesh, is significantly harder than anything 3d printing software has to do.
By the same standard, Chrome itself is "a tool to download files from Google's servers." Chrome doesn't only download from Google's servers, but the same thing applies to yt-dlp.
I'm equally not "surprised" by their bad behavior, but that shouldn't stop us from condemning Google for unethically misleading people and engaging in browser monopoly abuse.
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EDIT: holding up (hilariously) RIAA lawyers as ethical role models only proves my point, thanks.
Actually that is what they want you to believe. Behind the scenes, secretly Chrome is mostly "a tool to upload files to Google's servers" but because it does not require any actions from the user to do that, many people miss that part.
I am sure that RIAA lawyers would rofl at this yt-dlp labelling being an example of Google "... unethically misleading people and (committing) browser monopoly abuse". I want to live in that fantasy world with you though.
Come to our fantasy Linux land anytime you want. We circumvent all of the strange things both RIAA, MPAA, Google and many other companies do to attempt to lock information into a box with only one hole they allow you to look through.
Our fantasy land gets better every time your reality gets worse.
> Chrome itself is "a tool to download files from Google's servers."
...legitimately. While Google (I will reinforce: Google, not everyone) sees downloading of the videos and other content from the YouTube by third-party services as illegitimate because of YouTube's ToS. After all, they're making money from the YouTube Premium and "Download" option provided by it, so things like that are kinda expected to happen.
And no, I don't agree that it's right. While I can understand the position of Google, the method they (allegedly) used here... Well... I don't even know what to say. That's plainly wrong, in my opinion. After all, "download" is defined as "To transfer (data or a program) from a central computer or website to a peripheral computer or device." by The American Heritage Dictionary of the English Language (5th Edition), so when you just watch videos, you download them already, don't you? What about watching them in browser, somewhere in embed on some website? Does that constitute a legitimate client (I guess so, because most of embeds still use YouTube Player after all)? That just makes me laugh : )
Or just stochastic impacts with debris too small to track. Objects >1 cm are fatal to satellites, but ground radar can only track objects 10 cm or larger.
The two scenarios are pretty easy to distinguish. If the explosion occurred near the poles (above 75° latitude), it's most likely a random debris strike.
Sure enough, despite the fact that only 2.1% of Starlink satellites[0] are in orbits that go above 75° N/S, Starlink-34343 was one of those satellites.[1]
Plastics are chemical "sponges" that will soak up pollutants over time from the environment (brominated fire retardants, bisphenols, PBCs, pesticides, phthalates, heavy metals, etc) and deliver them in a concentrated dose into the body.
If anyone wants to actually use this, here are some uBlock Origin filters for the ISP-specific elements you probably don't need (remove the carets "^" for uBO Lite, it removes elements directly from the HTML to prevent flickering):
For instance the same thing happens with plastic tea bags in hot water: https://www.sciencedirect.com/science/article/pii/S004565352...
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