agurk

As with all design on aircraft, weight is a key part of the specification. A nacelle that could contain all possible failure modes would be too heavy to fly.

Losing a fan blade, as demonstrated in your two youtube links, is both a more likely event to occur and low enough energy to be able to contain with a reasonable structure.

However consider the situation in [0] where a turbine disk became detached from its shaft. The disk is still taking power from the exhaust gas, but rather using the energy to power the compressor or rotate the fan it is now just increasing its own kinetic energy. This continues until the incredibly strong turbine disk rotates itself apart. From the linked article:

For engineering purposes, disk fragments are assumed to have infinite energy at the moment of release; they will cut through any reasonable material and cannot be contained

You can see from photographs of the aftermath, the nacelle is missing where this happened

[0] https://admiralcloudberg.medium.com/a-matter-of-millimeters-...

There are some nuances to it. British Airways (not the original British Airways Ltd [0], who merged to form BOAC) was established to manage several existing airlines that had already been nationalised (BOAC, BEA) and two regional carriers (Cambrian Airways and Northeast Airlines).

Of course BOAC and BEA had been made my consolidations of many smaller airlines which gets messy quickly when tracing the lineage. Even Cambrian and Northeast had formed British Air Services prior to this which was 70% owned by BEA.

So it is technically true that is was started as a state owned airline, but one made from companies that were originally created as private with a mixed history of state ownership.

[0] https://en.wikipedia.org/wiki/British_Airways_Ltd

You may be thinking of a different film, as all the cast members listed on wikipedia[0] are stated to have died after 1945.

The trivia section of the German wiki page of the same film says there's a disputed rumour that the film was prolonged to help the young extras avoid conscription.

[0] https://en.wikipedia.org/wiki/Die_Feuerzangenbowle_(1944_fil...

They probably mean Lynetteholmen, which is a giant artificial peninsula to be built on reclaimed land off Copenhagen.

Curiously there's no English wiki page for it, but machine translation is good these days:

https://da.wikipedia.org/wiki/Lynetteholmen

The second route is currently being built in Munich [0], with work started in 2017. I recently watched a youtube video by The B1M about rail projects in Germany that included a long section about the currently ongoing works in Munich [1] that gives a good visual overview.

[0] https://db-engineering-consulting.com/en/projects/munichs-se...

[1] https://www.youtube.com/watch?v=bPDQdnT-RaY

On all the fuel injected engines I have owned there is a physical cable that controls the position of the throttle plate. There is an airflow mass sensor the other side of the plate to measure the amount of air and therefore how much fuel needs to be injected. So interestingly in these sort of engines you're really just controlling airflow to the engine rather than fuel/air mix like on one with a carburettor.

More modern engines have electronically controlled throttle plates, and this is definitely somewhere you could do something clever like you suggest - cutting fuel flow but also maximising airflow when there is zero throttle input.

I assume engine braking is generally considered a beneficial thing by manufacturers, but it could be fun to be able to customise the amount. Or do something like have the braking come on gently at first then harder. Maybe even try and have a linear or flat response curve vs. engine rpm.

If it takes energy to compress the air in the cylinder - doesn't it also release most of that energy when that compressed air is expanded on the subsequent stroke?

If you release the compressed air without pushing the cylinder down you would lose that energy, but you would need a extra device to do so (by lifting a valve at the right time). This option does exist for large vehicles like trucks as a compression release engine brake [0], but this isn't something you'd have on a family car.

In a petrol engine you always want the same ratio of petrol to air in the mix that is taken into a cylinder. As you want to vary the amount of fuel, and therefore power developed, you have to be able to therefore limit the amount of air that is sucked in. Otherwise the engine would always run at full power.

There is a mechanical restrictor called a throttle plate that lives inside the throttle body that restricts how much air the cylinder can pull in (and therefore how much fuel is injected to get the same fuel/air mix). This is controlled by the throttle. When you are coasting, this plate is in its most closed position. This creates significant resistance on the intake stroke, and is where the majority of energy is lost during engine braking. This is also known as a pumping loss.

Diesels always intake the same amount of air, so they can compress it enough to autoignite the fuel. They vary the amount of fuel injected to the same volume of air. This means no throttle body or plate, so unless an extra exhaust restrictor has been added there is minimal engine braking on a diesel engine.

[0] https://en.wikipedia.org/wiki/Compression_release_engine_bra...

Curiously I have the opposite problem with Too Good To Go - they never give me notifications of available things I might be interested in, even though I've set that I want them.

This is on Android though, so perhaps an ecosystem difference?

More people are alive today than have ever lived.

Assuming you meant died instead of lived to avoid a potentially nonsensical reading, this is not true.

It seems this factoid[0] has been around since the 1970s, and at least in 2007 it was estimated to be 6% of people who'd ever lived being currently alive [1]

[0] In the original sense of factoid - being fact-like, but not a fact (i.e. not true). C.f. android, like a man

[1] https://www.scientificamerican.com/article/fact-or-fiction-l...

You are absolutely correct about autorotation and helicopters not falling out of the sky. There is one nuance that the rotor blades still need to be able to rotate for this, and a failed gearbox can prevent that. Anecdotally that feels like the most common cause when I read about another crash in the North Sea.

Not all boots are made the same though. I had some bad luck with a pair of veldtschoen welted boots from the English firm Crockett and Jones in a custom leather. The commando sole split twice at the toe, which they repaired, but after less than five years of wear the lining at the heel had worn through.

I took them in to be rebuilt, but after inspection they said the stiffener had come loose, and nothing could be done. Here have your expensive and now broken boots back.

I'd assumed when I got them I'd be wearing them for decades, and at least a few rebuilds. Maybe there was something wrong with that specific pair, but I did have a goodyear welted sole randomly detach from a pair of six month old city shoes from the same firm. And yes I had been looking after my shoes (frequent cleaning and polishing, always using shoe trees, skipping days between wears, etc).

When I had a pair of Church's fall apart I put that down to them no-longer being a quality brand, but now I don't think you can guarantee a long life just as the shoe was expensive and from a reputable brand. I have many shoes that have lasted better (and now since covid I don't wear polished shoes daily), but that does sometimes feel like luck of the draw.

Some SLBMs (Submarine Launched Ballistic Missiles) use star sighting to correct their trajectory mid-flight. ICBMs launched from silos know exactly where they're starting from, whereas a submarine is both moving, at different depths and has some error to knowing exactly where it is. Missiles use inertial guidance, so knowing your starting your point is crucial.

How accurate a missile needs to be is a whole other dimension though. If the value of a missile is as retaliation to destroy a city (countervalue) then it can be a large warhead and "miss" by quite a margin but needs some form of credible survivability of an enemy first strike. If the missile is to be used to destroy enemy military installations (counterforce) then it needs to be a lot more accurate but usually the implication is as a first strike so less survivability is required.

When you have nuclear weapons that you can drop from manned aircraft, ICBMs from silos and SLBMs controlled by different military branches there is going to be a lot of politics over what the missile is for, which will determine its required accuracy, which will be a factor on if it needs star sighting.

An engine failing on an aircraft, especially a light aircraft, is not a guaranteed crash landing. It is a serious situation, however aircraft usually glide well. This means you have opportunities to find somewhere that is adequate for landing. Many aircraft with engine failures have landed safely on airstrips. Interestingly this is also the case with helicopters due to their ability to autorotate.

When you go around a tight corner and are thrown to one side, what term would you use for the tram's change in motion then?

Deceleration is a useful but non-technical term, like vegetable. A tomato is a fruit which is a tightly defined concept, but it is in this loose category of things called vegetables. It's still useful to be able to call it a vegetable.

From a physics perspective all changes in motion (direction and magnitude) are acceleration, and it's correct to say the designers had to consider acceleration in most (all?) directions when designing the tram. This is including gravity's, as they tend to give you seats to sit on, rather than velcro panels and straps like on space ships.

It is useful to say to your friend in the pub that you got thrown out of your seat due to the tram's heavy deceleration, rather than give a precise vector.

Trolling is a fishing technique [0] of slowly dragging a lure or baited hook from a moving boat, and is likely the meaning that online trolling takes it from rather than a creature from Scandinavian folklore [1].

There's definitely a metaphor to be made for trolling for data, that GP could have been intentionally making. I've certainly seen that idiom used before, although it could have been an eggcorn [2] for trawling.

[0] https://en.wikipedia.org/wiki/Trolling_(fishing)

[1] https://en.wikipedia.org/wiki/Troll_(slang)#Origin_and_etymo...

[2] https://en.wikipedia.org/wiki/Eggcorn

Boots (a large UK pharmacy chain) sells it, but it's "behind the counter" so you have to ask for it. They will also only sell you one pack of 12 per visit

It's the same for codeine-mixed products. Recently I got denied a simultaneous purchase of pseudoephedrine and ibuprofen/codeine - I was I was only allowed one.

I'm not sure if it's policy, law or I just looked suspicious.

Two 'weird' places I have visited this year that required an IDP were Japan and Taiwan.

Before the Ballmer/Zune use of the term I remember my father talking about data being squirted to A2A missiles (he was military) prior to launch, so perhaps that is one of the niches.

Interestingly helicopters don't fall out of the sky when they lose power. Air moving over the rotorblades causes lift, as they are after all wings. During normal flight the blades are turned by the engine generating lift in the expected way. If you are already above the ground and start descending, the airflow over the blades as you descend will cause them to rotate and generate lift. This is known as autorotation[0], and allows control over the unpowered descending craft.

It is a normal procedure to be able to safely land this way when power has been lost, and in some ways is safer than a gliding fixed wing aircraft as you don't need a runway to land on.

Of course catastrophic failure is possible in a helicopter where the rotorblades can't turn, and then autorotation won't work. But then if a wing falls off a fixed-wing aircraft, they generally can't be controlled (interesting exceptions do exist like with the Israeli F15[1]).

[0] https://en.wikipedia.org/wiki/Autorotation

[1] https://en.wikipedia.org/wiki/1983_Negev_mid-air_collision

With a roundabout, you only have to look in one direction

When being taught how to ride a motorcycle, one of the lessons is a series of extra checks that you're not taught when learning to drive a car. These are known as lifesaver checks.

Entering a roundabout is a left turn in Ireland (right turn in right hand drive countries) so you would check over your left shoulder to make sure nothing was on your left. This is performed after doing a normal right and ahead check for traffic already on the roundabout.

I have never caught anything with a roundabout lifesaver (I have in other situations) but I can see how it's useful on roundabouts with multiple entry lanes, or if something like a bicycle had appeared on your right.

I'm somewhat confused with the analysis of his predictions of the price of PV panels.

Is it saying Smil said (is that meant to be countered with?) PV would cost 0.05 USD/W in 2020? Or was that meant to be Al Gore claiming that price? It seems it can't be his predicted reduction as he said 25% less, so did he want to say that is would be 3.38 USD/W in 2020 (75% of the 2009 price)?

And the current cost - 0.2W/USD is 5 USD a Watt - are the units reversed there? A quick google shows a variety of prices, with nothing being 20 cents a Watt [0] - $0.5-1.50 for the less efficient thin film types quoted here. All seem quite a bit cheaper than $4.5 a watt though.

[0] https://www.forbes.com/home-improvement/solar/cost-of-solar-...

One detail here is that 1981 dollars aren't 2023 dollars, so to compare they need to be adjusted.

Using [0] $3.5 bn in 1981 would have been worth $11.7 bn in 2023.

Another comment [1] noted (but unfortunately didn't cite) that two years later the damage was assessed at $36 bn, or $110 bn in 2023 dollars.

[0] https://www.usinflationcalculator.com/

[1] https://news.ycombinator.com/item?id=41295116

Normal glasses are recyclable

Is this the case in reality? Everywhere I've lived drinking glasses were not accepted as part of domestic glass recycling due to their composition [0]

Perhaps there is a commercial recycling route for pubs though? A quick google didn't turn anything up.

[0] https://www.friendsofglass.com/ecology/what-glass-can-you-re...

I don't have an opinion on the health effects of sweeteners, but as I noted in a longer comment on this page, multiple sweeteners are commonly used together and aspartame is far from universal in the mix.

Virtually all artificially sweetened soft drinks in the Uk are sweetened with aspartame

A quick look at a few soft drinks I could think of, and their UK sweeteners:

  Fanta: Aspartame, Acesulfame 
  Coke Zero: Aspartame, Acesulfame-K, Enzymatically Produced Steviol Glycosides
  Pepsi: Acesulfame K, Sucralose
  Irn Bru: Aspartame, Acesulfame K
  Tizer: Acesulfame K, Sucralose
  Old Jamaica Ginger Beer: Sucralose
  Lipton Iced Tea: Steviol Glycosides from Stevia
  Ribena: acesulfame K, Sucralose

I'm not aware of a B-52 being crashed in a barrel roll, but this did make me think of the 1994 Fairchild crash[0] that was caused by a pilot who was known as dangerous due to excessive self confidence. In this case he banked too tightly at low level causing a stall into the ground. The whole crash was caught on camera[1], which is indelibly burnt into my memory.

[0] https://en.wikipedia.org/wiki/1994_Fairchild_Air_Force_Base_...

[1] https://theaviationgeekclub.com/the-story-of-bud-holland-the...

There is a very well written version of this from many years ago on the Daily WTF:

https://thedailywtf.com/articles/special-delivery

It is written well enough that I could just about convince myself this actually happened!

8 reached EOL in the last year or two

Java 8 is still under Extended Support until 2030 (and indefinite sustaining support). Java 11 left Premier Support September 2023.

"Java SE 8 has gone through the End of Public Updates process for legacy releases. Oracle will continue to provide free public updates and auto updates of Java SE 8 indefinitely for Personal, Development and other Users via java.com".

https://www.oracle.com/java/technologies/java-se-support-roa...

I went around Oregon in 2008 and it seemed every beer bar (like brewery taps and specifically beer themed, not just a regular bar) had a single beer engine, usually with some local real ale on it.

I've seen a few in NYC, usually Williamsburgy areas. Beer festivals might have a cask or two as well.

Otherwise I've very rarely seen it in the US.

I have an English uncle who grew up around the time lager became the go to beer in England. He drinks a variety of beers these days including ales and lagers, but when he was young only drank lager.

Many years ago I asked him why he switched to drinking larger when he was younger, and his answer boiled down to consistentcy/quality.

Ale in England is pumped by hand into a pint glass, with a quaintly named beer engine, from a cask (not keg). The casks are open, so each unit of beer extracted is replaced in the cask with air. This means many opportunities for infection and oxidation of the beer so it goes off very quickly, and the lines between the cask and the engine need frequent cleaning.

This is expensive and time consuming, so bad pubs often push it as long as they can before doing it, or often just let it go bad. I've been to one pub where I tried every ale and they were all off.

Back when my uncle was drinking in the 60s and 70s he found this very common, so ordering a pint of ale often meant you might get a bad beer.

Lager is in a keg which is CO2 pressurised, so any larger removed is replaced with CO2 this helps keep it drinkable for much longer. The CO2 overpressure is what forces it out of the keg, so it's served from a tap not an engine.

Ale isn't pressurised with CO2 as it has low carbonation, so using pressure to force it out would also carbonate it further and change the product. So that can't be used to extend its life. You can get a soft spile to put in the literal hole in the top of a cask, that keeps flies out, but still air flows in. There are devices called cask breathers that would replace the beer removed with a blanket of atmospheric pressure CO2 so no further carbonation, but much improved life of the beer. CAMRA in the UK fought hard against these as they claim ale needs some O2 to mature (maybe breathing like a wine). I think they fought too hard, harming ale sellers and drinkers. I don't know what their contemporary opinion on them are.