litchralee
@litchralee@sh.itjust.works
- Comment on Are standing seats on airliners actually going to be a thing? 4 days ago:
Setting aside whether such seats are actively hazardous to passengers for anything more than a short-haul flight – they almost certainly are – we can fairly easily rule out the possibility based solely on one of the more important airline test criteria: evacuation time.
For all commercial passenger airliners, the primary limiting factor for economy seating is how to get everyone out of the airplane in an emergency situation within the stipulated time, in ideal circumstances. In the USA, that time is 90 seconds, based on research that the inferno post-crash due to ruptured fuel tanks would only allow the plane to remain intact for about two minutes. Front that article, the largest passenger jet in the world – the Airbus A380 – could evacuate 873 people through 16 doors on two dual-aisle decks. A typical short-haul, single-aisle Boeing 737 has only six doors and carries a maximum of 230 passengers with the still-being-certified 737 MAX 10 variant.
The benefit of having more doors and more aisles must not be understated, but even then, another limiting factor is takeoff weight. Using the 737 MAX 10 as an example, the difference between its empty weight and takeoff weight is some 40,000 pounds. But 230 people already makes around 20,000 pounds, so the aircraft already cannot be fully loaded with its intended 44,000 pound fuel capacity. Packing more people into this aircraft would steal even more capacity and leaving the aircraft unable to support transcontinental USA flights.
But supposing that was overcome, and flights with so-called standing seats were only about 2 hours long or so, the problem would be with seat durability during a crash scenario. Jet airlines seats are designed to absorb energy, since excessive G-forces would kill a human, well before any fire might get to them. A seat which relies on legs for vertical support would be unable to adequately absorb downward forces from a hard touchdown, nor from forces from hitting an obstacle or being rammed from behind. These two directions are what humans are best able to cope with, and a standing seat steals these benefits away.
Thus, a seat that complies with energy absorption requirements would be at least as thick as existing seatbacks, and would probably be thicker or heavier, further reducing available payload.
The only conceivable revenue service would be one where economy class uses so-called standing seats, in order to free up room for business or first-class seats, staying within the existing seat limits for existing aircraft. However, the time to board such an aircraft would be noticeably slower than with a conventional seat aircraft, so at some point, such an airliner would need to consider whether a stopped aircraft loading passengers is better value than an aircraft which can be quickly turned around for another flight segment.
All of these factors point to a technical inability to squeeze more passengers into less space. And remember that there’s no free lunch: a “standing” passenger frees up space between rows, but requires more height at each seat. At least from my experience, one cannot stand up in a conventional seat, without hitting the ceiling. How would a typical 5 ft 9 in (175 cm) American be able to use a “standing” seat safely?
I personally discount the possibility of “standing” seats deployed on existing and proposed aircraft, so it would be at least 10-20 years before we even see such a thing for revenue passenger aircraft.
- Comment on Besides money/capitalism, why are tech companies trying to push AI text generators over search engines? 1 week ago:
Money and incentives are very powerful, but also remember that these organizations are made of humans. And humans are vain.
Amassing station and power can scarcely be divorced from the history of human civilization, and even fairly trivial things like the job title of “AI engineer” or whatever might be alluring to those aspiring for it.
To that end, it’s not inhuman to pursue “the next big thing”, however misguided that thing may be. All good lies are wrapped in a kernel of truth, and the fact is that machine learning and LLMs have been in development for decades and do have a few concrete contributions to scientific endeavors. But that’s the small kernel, and surrounding it is a soup of lies, exaggerations, and inexactitudes which somehow keep drawing more entities into the fold.
Governments, businesses, and universities seem eager to get on the bandwagon before it departs the station, but where is it heading? Probably nowhere good. But hey, it’s new and shiny, and when nothing else suggests a quick turnaround for systemic government, economic, or academic issues (usually caused by colonialism, fascism, debt, racism, or social change), then might as well hitch onto the bandwagon and pray for the best.
- Comment on [deleted] 2 weeks ago:
I’m not a pilot but have always looked to the open skies with dreams and admiration. I think we need to unpack a few assumptions.
something that’s very forbidden in the aviation world because of lightning
Weather (WX) has always been an integral part of aviation, as early as the lighter-than-air (ie hot-air balloon) days. The strength of human kind is no match to what nature can throw at us, and so instead we adapt to what nature gives us. On one hand, nature provides niceties like prevailing wind and thermals, to allow us to build runways pointing into the wind and for gliders to gain altitude. On the other hand, nature can decide that an Icelandic volcano shoots hundreds of thousands of tons of particulate matter into the air, grounding all commercial flights in European airspace.
Resilience becomes the objective, to safely operate revenue aircraft in the face of fickle natural phenomena. And this is achieved in a multi-layer approach, with resilience baked in at every step. The aircraft itself, the crew, the airports, ATC, and the regulators, they all are trained and briefed on known hazards, which is part of why commercial aviation is one of the safest modes of travel, sans maybe the elevator.
Unlike volcanic activity or windshears/microbursts, thunderstorms and lightning give plenty of warning through day-ahead WX forecasts, as well as onboard radar. These are not fool-proof – for example, radar can be shadowed by nearby precipitation, hiding enormous thunder clouds beyond. But despite how terrifying it may sound to fly through a storm, it isn’t impossible and certainly not unmanageable. But it does take preparation, and requires sufficient margins so that if anything starts to look awry, there’s an escape path.
Often times, the escape path is just to climb away.
Lightning struck the plane … which could’ve been catastrophic
There are many things which are potentially catastrophic for aircraft: loss of engines, loss of pressurization, a lithium ion battery fire in the cargo compartment, a medical emergency while overflying the mid-Atlantic.
But while a gut-reaction would be to outright avoid risk, human endeavors can make no progress like that. So instead, worst-case planning means developing procedures for when not if something bad happens.
Aircraft are designed to take lightning strikes, and although the Boeing 787 uses a lot of composite material, it too has provisions for lightning.
the report for this incident
Seeing as the incident here occurred on 17 March 2025, I wouldn’t expect the Japan Transport Safety Board (JTSB; the air safety regulator, equivalent to USA NTSB) to have published a final report. There might be a preliminary report, but this is not that.
This appears to be a collection of ADS-B data, a mention of damage to a control surface, and a Twitter post about airline compensation due to diverting from Haneda (HND) to Narita (NRT).
Were it not for the control surface damage, this incident might have fallen below the threshold for reporting, since no source suggests there were injuries and I don’t see – having not watched the video – an emergency being declared by the pilots. Diversions are not wholly uncommon, for a number of operational or WX reasons.
I’m pretty sure if a US or European pilot did this, they’d get their license revoked
I think this is wrong, based solely on the robust safety culture in both the USA and in European airspace. Safety culture means that procesures are developed to manage risk, these procedures are regularly practiced, are updated with the latest available recommendations, and non-wilful deviations from procedure (aka mistakes) will be addressed by additional training, not by punishment.
As Mentour Pilot eloquently reminds viewers of his YouTube channel, if punishment were metted out for every mistake, then it’s a disincentive to report mistakes, which makes safety worse for everyone.
No doubt, there are pilots which have operated grossly outside the bounds of acceptability, like flying an empty jet into coffin corner, or allowing a child to fly the plane. Such accidents are reported precisely because they blew through every layer of the Swiss cheese model of accident causation, and tragically took lives.
So with all that out of the way, I think we can still try to answer the titular question.
A scheduled passenger airliner tries to get passengers from airport A to airport B. A lot of prep is done in the background to make this happen, organizing the ground crew, flight crew, and backend operations at the airliner HQ. Most of the time, the flight is uneventful and arrives as expected. A few times, there might a go-around, but pilots are trained to not shy away from doing a go-around, and have the reserve fuel to do so.
With any sort of damage on approach, be it from a bird strike or lightning strike, the pilots will have to: 1) secure the plane, usually by initiating a go-around to buy valuable time and get away from the ground, and 2) assess the condition of the airplane and make a plan. In this case, the airplane diverted to a nearby airport, which was probably the backup destination airport.
As mentioned before, WX is fickle, and a storm can easily creep over the airport when the plane is within radio contact. And even if the storm was already over the arrival path, if the indications are still suitable for landing – eg low crosswind, no tailwind, no predicted windshears, no prior pilot reports of landing troubles – then the pilots will have discretion to continue their approach.
For a healthy safety culture, the airliner’s own procedures have to place the pilots as the ultimate decision-makers once a flight is underway, and so while it’s unfortunate that damage occurred unexpectedly, nothing from the minimal available information suggests this amounts to a systemic or procedural error, nor wilful malfeasance.
The fact that the airliner returned to service days later means this might simply be slightly more than mundane happenings. Though it would be prudent to keep an eye out for a future report from the safety regulator.
- Comment on if pure water is not conductive why would condensation be an issue for electronics? 2 weeks ago:
Wireless water, coming right up: www.youtube.com/watch?v=j_QfX0SYCE8
In all seriousness, not all participate sticks to water vapor, if said particulate is non-polar – the lipid envelope of one SARS-CoV2 comes to mind. It would be more effective to clean the air using a furnace filter taped to a box fan, and it’s only up from there: electrostatic filters or actual air cleaners with a filter.
That said, some console humidifiers push air through essentially a large sponge, and that can already be effective at trapping larger particulate, although not effective for tiny virus-sized particles.
- Comment on if pure water is not conductive why would condensation be an issue for electronics? 2 weeks ago:
If water vapor was the only thing airborne, then this would be mostly plausible. But the reality in any typical environment is for small particles of dust, soot, microplastics, COCs, etc to be in the air, in addition to the usual suspects of oxygen, nitrogen, carbon dioxide, etc. Some of those will increase the conductance of water, when condensed upon a cool surface. Think of water vapor as a lint filter that floats around the room until it lands on something.
But even in a hermetically sealed environment with only the typical atmospheric mix of oxygen and nitrogen and other trace elemental gases, and then water vapor, there’s still a problem. Air has a conductivity – measures in Siemens, the inverted unit of Ohms which is resistance – of 3-8 x 10^15, meaning it will not conduct much at all. But compared to condensation upon a PCB in this sealed environment, DI water has a conductance of 5.5 x 10^6. That is 100,000,000x times more conductive, although it’s still a tiny amount.
The reality is that all circuits and electronics leak small currents here and there, even through the air or through their PCB substrates. But the sum total of these leakage and creepage currents will be negligible in all but high-voltage cifcuits. Though that’s only under the rated environmental conditions.
When air is fully saturated at 100% humidity, some of those currents become noticeable. And for high-voltage switchgear, it can become an issue very quickly. But iutright water on most circuit would be disastrous due to arcing or shorting, or both.
- Comment on How would legal procedure change if every citizen eligible for jury duty was aware of jury nullification? 3 weeks ago:
Supposing that any change did materialize, it is a bedrock principle of legal procedure to not change substantially just because the outcomes have noticeable changed. That is to say, if there was anything like a sudden drop in conviction rates, it would be improper for the judges, appellate justices, and defense and prosecuting attorneys to do anything different than what they would have done prior. That’s kinda the point of having a procedure: to follow it and see what happens.
The source for such changes would have to be brought legislatively, since – at least in the USA/California – that’s how changes to the law and civil/criminal procedure are made. Sure, entities like the Judicial Council of California would be making recommendations, but it’s on the Legislature to evaluate the problem and implement any necessary changes.
- Comment on [deleted] 4 weeks ago:
TIL
- Comment on [deleted] 4 weeks ago:
The remarkable thing is that modern chip-and-pin cards do support that sort of “offline” transaction, although fortunately without the carbon copy paper. Specifically, a non-networked credit card terminal can present a transaction to the chip, the chip will cryptographically sign this transaction in a unique way, and the terminal will store it for later submittal to the credit card company, when an online connection is possible.
For a typical “online” transaction when there are no connectivity issues, the third step would send the transaction immediately to the credit card company, so they can have the option of declining the charge. The cryptography is otherwise the same, and it’s why offline transactions are possible.
Some vendors like SNCF (the national rail operator) in France use offline transactions for their ticket vending machines at rural stations, where there’s no guarantee of being within mobile phone service. The card issuer also usually programs some safeguards to prevent abuse, such as X number of offline max and then an online transaction is mandatory, or a limit on the value of purchases (eg $50 max for offline). After all, there cannot be a check against one’s credit limit when offline.
In the USA, it is exceedingly rare for credit cards to be issued as chip-and-pin, and while offline transactions can be performed with chip-and-signature cards, it’s rarely enabled since most/all terminals in the USA have been online since the introduction of electronic credit card processing.
Contactless chip cards might have changed the calculus though, since there is no PIN at all for these transactions. So perhaps issuers might allow a few offline transactions when contactless.
- Comment on [deleted] 4 weeks ago:
For buses in particular, bear in mind that liquid fuels typically require pumping, which usually uses electricity. So gasoline or diesel pumps might not be available, even if the underground storage tank has fuel. Here in California, a lot of public buses are fueled with Compressed Natural Gas (CNG) which in theory could have already been compressed at the depot, but this would only last so long, since it takes energy to run the compressor, assuming the natural gas pipeline is unaffected.
Obviously, electric buses and trolleybuses need electricity. So at this point, perhaps the only bus that would be totally immune is an omnibus, that 19th century people-mover that was drawn by horses. But consider the “emissions” from a horse though…
In all seriousness, the contingency plans for a transit agency will vary depending on where you are in the world. For American transit agencies, most don’t even offer service on Sunday or holidays (very strange in the land of hyper religiousness; no bus to church??) and any labor strikes usually result in every service being closed, sometimes including essential ADA operations.
- Comment on In the United States; is it illegal to use a single serve wrapped slice of Kraft cheese as a postcard? 4 weeks ago:
At the very minimum, this type of mail would incur the $0.46 non-machinable surcharge because it’s smaller than one of the minimum USPS dimensions for postcards, namely that one size has to be 5 inches (127 mm exact). You may also have issues with it being too floppy for basic handling by the postal carrier, especially if it was previously left in a warm mailbox.
But perhaps a more practical issue may arise first: will stamps even adhere to the wrapping of a Kraft Cheese single? If you cannot affix postage, that’s the most immediate impediment.
- Comment on If I snapped you back in time 650 years right this very second, how would you use your current knowledge to succeed? 4 weeks ago:
no rubber for seals
Modern synthetic rubber would indeed be unavailable, but I vaguely recall reading something to the effect that early steam engines used leather seals or something like that.
But yeah, there’s a lot of missing prerequisites for machinery. Even simple rotary power – like from a windmill or waterwheel – would suffer from being incapable of long distance transmission
- Comment on 4 weeks ago:
should
when it comes to legality
This needs clarification. Are you asking about the legal status of Character AI’s chatbot, and how its output would be treated w.r.t. to intellectual property rights? Or about the ethical or moral questions raised by machine-generated content, and whether society or law should adapt to answer those questions?
The former is an objective inquiry, which can be answered based on the current laws for a given jurisdiction. The latter is an open-ended, subjective question for which there is no settled consensus, let alone a firm answer one way or another.
I decline to answer the latter, but I think there’s only one answer for the objective law question. IANAL, but existing fanfiction does not imbue its author with rights over characters from another author, at least in the USA. But fanfiction authors do retain copyright over their own contributions.
So if an author writes about the 1920s Mickey Mouse character (now in public domain) but set in a gay space communist utopia, the plot of that novel would be the author’s intellectual property. But not the character itself, which remains public domain. However, character development that happens would be the author’s property, insofar as such traits didn’t exist before.
What aspects of this situation do you envision would require different treatment just because it’s the output from a chatbot? Barring specific language in a Terms of Use agreement that transfers ownership to the parent company of Character AI chatbot, machines – and gorillas – are not eligible to own intellectual property. The author would be the human being which set into motion the conditions for the machine to produce a particular output.
In conventional writing, an author does not relinquish ownership to Xerox Corporation just because the final manuscript was printed using a Xerox-made printer. But just because an author uses a machine to help produce a work, that will not excuse plagiarism or intellectual property violations, which will accrue against the human being commiting that act.
(I express no opinion on whether intellectual property is still a net positive for society, or not)
- Comment on What's the point in getting married? 4 weeks ago:
There’s at least !bestoflemmy@lemmy.world
- Comment on How do man made hiking trails keep the grass from overgrowing? 4 weeks ago:
I should clarify that my original comment – foot traffic keeps paths in decent shape – was in answer to the OP’s titular question, about why vegetation doesn’t grow atop the intended walking/hiking trail. But you’re right that traffic will cause other impacts, even if plantlife isn’t getting in the way.
I’m in 100% agreement that for trail upkeep, people have to be mindful how they step. The advisories here in California focus on not eroding the edges of the trail, such as by walking around muddy areas, which would only make the restoration work harder and damage more of the adjacent environment. We have a lot of “stay on trail” signs. We advise people to either be prepared to go right through the mud – only worsens an existing hole – or don’t walk that trail at all.
- Comment on How do man made hiking trails keep the grass from overgrowing? 5 weeks ago:
Obligatory reference to desire paths: !desire_paths@sh.itjust.works
- Comment on [deleted] 5 weeks ago:
My understanding is that the de minimis tariff treatment for import shipments is different than the duty-free personal exemptions that apply for “accompanied baggage” when re-entering the USA.
Assuming this CBP page is accurate, the $800 exemption is one of three possible exemptions that can still apply. The $1600 exemption only applies when returning with stuff from Guam, American Samoa, or USVI, and the $800 can only be claimed every 30 day. The last resort is the $200 exemption, which is always available, and ostensibly is there to allow Americans living near Canada or Mexico to not have to deal with border taxation just because they had to buy lunch or gasoline during day trips.
- Comment on Why do some drivers turn off the signal sound so quickly? 1 month ago:
Is this question about drivers that turn off their indicators while still mid-turn? Or about drivers that turn or change lanes in very little time at all?
IMO, the correct time to use indicators is precisely when in preparation for a turning or lane-change manoeuvre, during such manoeuvre, and that’s it. Once the manoeuvre is done, the indicators should be extinguished to avoid ambiguity, unless a follow-up manoeuvre is planned.
I see no logical reason to enforce a prescribed minimum for indicator time, and it’s why I see minimum-three-blink on some modern cars as an anti-feature. After all, there’s no minimum (nor maximum) time to prepare and make a turning manoeuvre.
To use a USA example, the driving style of Los Angeles Intercity freeways is – for betre or worse – going to necessitate fairly quick lane changes, because of the tighter spacing between cars. In hard figures, a lane change might be prepped and done in 3 seconds. Some might say that all these drivers are violating good driving behaviors for following each other so closely, but it’s sadly a practical necessity when no amount of “just one more lane” can solve the systemic issues with regional road transportation there; it’s why LA is doubling down on public transit building.
Compare this with changing lanes on a rural Interstate freeway to pass a semi-truck, where a lane change can be more sedate because there might not be any other traffic in sight except for the two vehicles involved. Smooth driving on a road-trip might have this manoeuvre prepped and completed over 10-15 seconds, as the car might also be accelerating while also changing lanes.
In both circumstances, the indicators should remain blinking while mid-manoeuvre. Anything short of that is “too quick” in my book.
But if your question is how far in advance should drivers begin indicating before the manoeuvre, that’s a joint matter of regional convention and of law. And the former usually is the strongest influence.
- Comment on What efforts would it take to strip the name Americans from the folks inhabiting the US? 1 month ago:
But outside it’s a very different story especially in places where the language isn’t English.
What is the demonym for something that can be found or belongs to “The Americas”, comprising both North and South America (and potentially Central if you go by the Three Americas way of splitting the continent)?
This is a fair question, and I suspect there simply is no generally accepted demonym in English. One could be introduced, but contrast that fairly simple exercise with the replacement of the broadly-recognized demonym for USA residents: “American”. Quickly, it becomes apparent that replacement is far harder than introducing a new demonym, even if the demonym itself isn’t very logical within the English language.
English is the same language that calls people from Deutschland as “German”, and then American English specifically might also call them “Dutch”, as in, the Pennsylvania Dutch, whom immigrated from Germany. Consistency is not strong in the English language, even over only a few hundred years.
- Comment on What efforts would it take to strip the name Americans from the folks inhabiting the US? 1 month ago:
I’ve not known any USA residents that call the continent as “America”. Instead, the continent – which in this case basically just means USA + Canada – would be “North America”. And if they meant the whole post-1490s “New World”, it would be “The Americas” for both North and South America together.
- Comment on How can you oppose tariffs, while supporting a hardline against China on Taiwan? 1 month ago:
Thank you for you kind words!
- Comment on How can you oppose tariffs, while supporting a hardline against China on Taiwan? 1 month ago:
I had an inkling that was the case. But I figured that, for my own benefit, I’d elucidate my position a bit more. If it falls on deaf bot ears, then that’s just how it is. There’s not much else I was going to say anyway.
- Comment on How can you oppose tariffs, while supporting a hardline against China on Taiwan? 1 month ago:
I agree that requiring certain industries to be based domestically is the best route
This isn’t what I said at all. What I meant was, for service businesses (eg car dealerships, warehouses, restaurants) and heavy industry (eg oil refineries, plastics and chemicals, composites like wind turbine blades or aircraft fuselages) which practically must remain within the country, support those endeavors by making it easier or cheaper to operate, so that an internal economy for those products develops locally. Trying to force stronger internal ties would inevitably lead to resources and incentives spent where they’re not most needed.
If you don’t tariff everyone, how does that bring manufacturing back? They’ll just move to the next cheapest country, and then you’re playing whack-a-mole.
I’m not sure if you saw my Mexico example or not, but manufacturing that moves from China to Mexico would still further a USA policy of reduced economic dependency on China. It doesn’t matter so much that it’s not “Made in USA” so much that it’s not “Made in China”, if that’s the desired economic policy.
And that doesn’t even include the knock-on effects that anchoring the Mexican economy would create: economic migration – when people move from a place of poorer economic condition to a richer economic place – would naturally abate if the Mexican economy grew. Economic opportunity also displaces gang warfare and drug distribution, in part.
The alternative is to apply huge subsidies for manufactures to ignore Mexico and set up shop in the USA, but then the cost of land, labor, and capital is substantially higher, and the products less affordable because they must be higher priced to pay for those means of production. Why do all this when Mexico or Canada are right next door?
- Comment on How can you oppose tariffs, while supporting a hardline against China on Taiwan? 1 month ago:
If you don’t support tariffs to bring back manufacturing jobs domestically, how do you think we could make it through a war with our manufacturing partners?
I express no position here about China nor Taiwan, but the false dichotomy presented is between: 1) enforce trade barriers indiscriminately against every country, territory, and uninhabitable island in the world without regard for allies nor enemies, or 2) diversify economic dependency away from one particular country.
The former is rooted in lunacy and harkens back to the mercantilism era, where every country sought to bring more gold back home and export more. The latter is pragmatic and diplomatic, creating new allies (economically and probably militarily) and is compatible with modern global economic notions like comparative advantage, where some countries are simply better at producing a given product, so that other countries can focus on their own specialization.
As a specific example, see Mexico, which under NAFTA and USMCA stood to be America’s new and rising manufacturing comrade. Mexico has the necessary geographical connectivity to the mainland USA, its own diverse economy, relatively cheap labor, timezones and culture that make for easier business dealings than cross-Pacific, and overall was very receptive to the idea of taking a share of the pie from China.
Long-term thinking would be to commit to this strategic position, this changing the domestic focus to: 1) replace China with North America suppliers for certain manufactured goods, 2) continue to foster industries which are “offshore-proof”, such as small businesses that simply have to exist locally or industries that remain super-expensive or hazrdous to ship (eg lithium ion batteries).
It is sheer arrogance to believe that the economic tide for industries of yore (eg plastic goods, combustion motor vehicles, call centers) can be substantially turned around in even a decade, when that transition away from domestic manufacturing took decades to occur.
- Comment on [deleted] 1 month ago:
300 kph is 186 mph, which is well beyond the posted speed limit of any jurisdiction I can think of. For reference, here in California, a conviction for driving over 160 kph (100 mph) is punishable as a felony, meaning at least one year in state prison. The highest speed limit in California is 113 kph (75 mph).
In metric units, a triple digit speed (eg 100 kph) is the domain of motorways (aka freeways or expressways). And even arrow-straight motorways have a maximum posted speed limit of some 140 kph. In Germany, the motorway can sometimes have no limit, but the recommended speed – the yellow speed limits in the USA – for German autobahns is 130 kph, with some speedy cars occasionally doing 200 kph, I’ve heard.
For further reference, the fastest speed achieved during an F1 motor race is 372 kph. Also, Japanese bullet trains heading west from Tokyo on the Tokaido Shinkansen route run at 285 kph.
300 kph on a public road is grossly irresponsible, since even with no one around, the road is not designed for that speed. Compare race tracks with freeways, and it becomes clear that surface quality, drainage, sight lines, clear space, and other requirements for 200+ kph just aren’t present on public roads, with the notable exception of very special public roads like the Nürburgring.
- Comment on Why do some say they own or have bought something that they technically haven't (e.g. domain names, expensive things, etc.)? 1 month ago:
FYI, some domains can genuinely be acquired for an indefinite period, as the delegation has no expiration period. So long as the domain is kept in good standing (eg two working authoritative nameservers) and doesn’t violate the parent domains’ policies, it will persist. Granted, few people go through this rather-old process to get such domains but they do exist. See my earlier comment.
- Comment on Other than a faulty charging port, is there any reason to use a wireless phone charger over wired? 1 month ago:
I’m also old, but I understand people do watch portrait videos. Sometimes a lot of them, in a single sitting. There’s a popular social media app which exclusively has short-form portrait videos.
- Comment on Other than a faulty charging port, is there any reason to use a wireless phone charger over wired? 1 month ago:
Some charging pads also prop up the phone at an angle, making it easy to read the screen while also not having to hold the phone up. Most phones have their charging port on the bottom, so a phone stand couldn’t be used while charging with a cord.
- Comment on Should I withdraw/stop putting into my 401k? 1 month ago:
This 100%. The other comments addressed the “should I withdraw?” aspect of OP’s question, but this comment deals with “should I stop contributing?”. The answer to the latter is: no.
The mantra in investing has always been “buy low, sell high”. If the stock market is down, continuing your 401k contributions is doing the “buy low” part.
- Comment on how do they decide where to put bus stops? 2 months ago:
I can understand the pessimism in some of the answers given so far, especially with regards to the poor state of American public transit. But ending a discussion with “they guess” is unsatisfactory to me, and doesn’t get to the meat of the question, which I understand to be: what processes might be used to identify candidate bus stop locations.
And while it does often look like stops are placed by throwing darts at a map, there’s at least some order and method to it. So that’s what I’ll try to describe, at least from the perspective of a random citizen in California that has attended open houses for my town’s recently-revamped bus network.
In a lot of ways, planning bus networks are akin to engineering problems, in that there’s almost never a “clean slate” to start with. It’s not like Cities Skylines where the town/city is built out by a single person, and even master planned developments can’t predict what human traffic patterns will be in two or three decades. Instead, planning is done with regards to: what infrastructure already exists, where people already go, and what needs aren’t presently being met by transit.
Those are the big-picture factors, so we’ll start with existing infrastructure. Infra is expensive and hard to retrofit. We’re talking about the vehicle fleet, dedicated bus lanes, bus bulbs or curb extensions, overhead wires for trolleybuses, bus shelters, full-on BRT stops, and even the sidewalk leading up to a bus stop. If all these things need to be built out for a bus network, then that gets expensive. Instead, municipalities with some modicum of foresight will attach provisos to adjacent developments so that these things can be built at the same time in anticipation, or at least reserve the land or right-of-way for future construction. For this reason, many suburbs in the western USA will have a bulb-out for a bus to stop, even if there are no buses yet.
A bus network will try to utilize these pieces of infrastructure when they make sense. Sometimes they don’t make total sense, but the alternative of building it right-sized would be an outlandish expense. For example, many towns have a central bus depot in the middle of downtown. But if suburban sprawl means that the “center of population” has moved to somewhere else, then perhaps a second bus depot elsewhere is warranted to make bus-to-bus connections. But two depots cost more to operate than one, and that money could be used to run more frequent buses instead, if they already have those vehicles and drivers. Tradeoffs, tradeoffs.
Also to consider are that buses tend to run on existing streets and roads. That alone will constraint which way the bus routes can operate, especially if there are one-way streets involved. In this case, circular loops can make sense, although patrons would need to know that they’ll arrive at one stop and depart at another. Sometimes bus-only routes and bridges are built, ideally crossing orthogonal to the street grid to gain an edge over automobile traffic. In the worst case, buses get caught up in the same traffic as all the other automobiles, which sadly is the norm in America.
I can only briefly speak of the inter-stop spacing, but it’s broadly a function of the service frequency desired, end-to-end speed, and how distributed the riders are. A commuter bus from a suburb into the core city might have lots of stops in the suburb and in the city, but zero stops in between, since the goal is to pick people up around the suburb and take them somewhere into town. For a local bus in town, the goal is to be faster than walking, so with 15 minute frequencies, stops have to be no closer than 400-800 meters or so, or else people will just walk. But then a service which is purely meant to connect between two bus depots would prefer a few more stops in between that make sense, like a mall, but maybe not if it can travel exclusively on a freeway or in a dedicated bus lanes. So many things to consider.
As for existing human traffic patterns, the new innovation in the past decade or so has been to look at anonymized phone location data. Now, I’m glossing over the privacy concern of using people’s coarse location data, but the large mobile carriers in the USA have always had this info, and this is a scenario where surveying people about which places they commute or travel to is imprecise, so using data collected in the background is fairly reliable. What this should hopefully show is where the “traffic centers” are (eg malls, regional parks, major employers, transit stations), how people are currently getting there (identifying travel mode based on speed, route, and time of day), and the intensity of such travel in relationship to everyone else (eg morning/evening rush hour, game days).
I mentioned surveys earlier, which while imprecise for all the places that people go to, it’s quite helpful for identifying the existing hurdles that current riders face. This is the third factor, identifying unmet needs. As in, difficulties with paying the fare, transfers that are too tight, or confusing bus depot layouts. But asking existing riders will not yield a recipe for growing ridership with new riders, people who won’t even consider riding the existing service, if one exists at all. Then there’s the matter of planning for ridership in the future, as a form of induced demand: a housing development that already sits on an active bus line is more likely to create habitual riders from day 1.
As an aside, here in California, transit operators are obliged to undergo regular analysis of how the service can be improved, using a procedure called Unmet Transit Needs. The reason for this procedure is that some state funds are earmarked for transit only, while others are marked for transit first and if no unmet needs exist, then those funds can be applied to general transport needs, often funding road maintenance.
This process is, IMO, horrifically abused to funnel more money towards road maintenance, because the bar for what constitutes an Unmet Transit Need includes a proviso that if the need is too financially burdensome to meet, they can just not do it. Thats about as wishy-washy as it gets, and that’s before we consider the other provisio that requires an unmet need to also satisfy an expectation of a certain minimum ridership… which is near impossible to predict in advance for a new bus route or service. As a result, transit operators – under pressure to spend less – can basically select whichever outside consultant will give them the “this unmet transit need is unreasonable” stamp of disapproval that they want. /rant
But I digress. A sensible bus route moves lots of people from places they’re already at to places they want to go, ideally directly or maybe through a connection. The service needs to be reliable even if the road isn’t, quick when it can be, and priced correctly to keep the lights on but maybe reduced to spur new ridership. To then build out a network of interlinking bus routes is even harder, as the network effect means people have more choices on where to go, but this adds pressure on wayfinding and fare structures. And even more involved is interconnecting a bus network to a tram/tram/LRT system or an adjacent town’s bus network.
When they’re doing their job properly, bus routing is not at all trivial, and that’s before citizens are writing in with their complaints and conservatives keep trying to cut funding.
- Comment on Why don’t wireless connections (WiFi, Bluetooth, etc.) use anything between 2.4Ghz and 5Ghz? 2 months ago:
have bandwidth that is some % of carrier frequency,
In my limited ham radio experience, I’ve not seen any antennas nor amplifiers which specify their bandwidth as a percentage of “carrier frequency”, and I think that term wouldn’t make any sense for antennas and (analog) amplifiers, since the carrier is a property of the modulation; an antenna doesn’t care about modulation, which is why “HDTV antennas” circa 2000s in the USA were merely a marketing term.
The only antennas and amplifiers I’ve seen have given their bandwidth as fixed ranges, often accompanied with a plot of the varying gain/output across that range.
going up in frequency makes bandwidth bigger
Yes, but also no. If a 200 kHz FM commercial radio station’s signal were shifted from its customary 88-108 MHz band up to the Terahertz range of the electromagnetic spectrum (where infrared and visible light are), the bandwidth would still remain 200 kHz. Indeed, this shifting is actually done, albeit for cable television, where those signals are modulated onto fibre optic cables.
What is definitely true is that way up in the electromagnetic spectrum, there is simply more Hertz to utilize. If we include all radio/microwave bands, that would be the approximate frequencies from 30 kHz to 300 GHz. So basically 300 GHz of bandwidth. But for C band fibre optic cable, their usable band is from 1530-1565 nm, which would translate to 191-195 THz, with 4 THz of bandwidth. That’s over eight times larger!
For less industrial use-cases, we can look to 60 GHz technology, which is used for so-called “Wireless HDMI” devices, because the 7 GHz bandwidth of the 60 GHz band enables huge data rates.
To actually compare the modulation of different technologies irrespective of their radio band, we often look to special efficiency, which is how much data (bits/sec) can be sent over a given bandwidth (in Hz). Higher bits/sec/Hz means more efficient use of the radio waves, up to the Shannon-Hartley theoretical limits.
getting higher % of bandwidth requires more sophisticated, more expensive, heavier designs
Again, yes but also no. If a receiver need only receive a narrow band, then the most straightforward design is to shift the operating frequency down to something more manageable. This is the basis of superheterodyne FM radio receivers, from the era when a few MHz were considered to be very fast waves.
We can and do have examples of this design for higher microwave frequency operation, such as shifting broadcast satellite signals down to normal television bands, suitable for reusing conventional TV coax, which can only carry signals in the 1-2 GHz band at best.
The real challenge is when a massive chunk of bandwidth is of interest, then careful analog design is required. Well, maybe only for precision work. Software defined radio (SDR) is one realm that needs the analog firehose, since “tuning” into a specific band or transmission is done later in software. A cheap RTL-SDR can view a 2.4 MHz slice of bandwidth, which is suitable for plenty of things except broadcast TV, which needs 5-6 MHz.
LoRa is much slower, caused by narrowed bandwidth but also because it’s more noise-resistant
I feel like this states the cause-and-effect in the wrong order. The designers of LoRa knew they wanted a narrow-band, low-symbol rate air interface, in order to be long range, and thus were prepared to trade away a faster throughput to achieve that objective. I won’t say that slowness is a “feature” of LoRa, but given the same objectives and the limitations that this universe imposes, no one has produced a competitor with blisteringly fast data rate. So slowness is simply expected under these circumstances.
In the final edit of my original comment, I added this:
Radio engineering, like all other disciplines of engineering, centers upon balancing competing requirements and limitations in elegant ways. Radio range is the product of intensely optimizing all factors for the desired objective.