Why should passengers not delay donning emergency oxygen masks after they deploy from the overhead compartments?

A

As soon as the oxygen masks fall down, the flight crew will know, and they will make it an immediate priority to get the aircraft down to an altitude where the masks are not needed anymore because the outside pressure is high enough to breathe by. This takes less than the time the oxygen generators last for.

(Usually descending will take much less time than the masks are good for -- the critical design factor for the oxygen mask duration is that if you happen to be over tall mountains when the pressure drops you may need to fly for a bit of time to reach terrain low enough to dispense with the masks. There are a few places, such as over the Tibetan plateau, where airline flights simply don't go because it's too far from sufficiently low terrain for the masks to last).

There is no realistic chance of the oxygen generators running dry while you still need them. If you delay putting your mask on, all you buy is a danger of fainting or otherwise being unable to don it (from low pressure, not depletion of oxygen in the air) before you decide to put it on -- and then you may end up in a low-oxygen state for long enough to risk permanent harm.

There's a reason why the safety briefing always instructs you to put your own mask on before helping others -- because the time it takes to help someone else may well be enough to incapacitate yourself. //

In a typical decompression, there will be a gradual loss of pressure. However, by the time the masks drop, the pressure has already dropped a fair amount. There is no set time that it takes for pressure to drop. It could be very gradual, or it could be explosive decompression that happens extremely quickly. As a passenger, aside from the obvious explosive decompression, you will not be able to tell how fast the pressure is dropping. And because of how hypoxia works, you many not even be able to tell that you are not getting enough oxygen. So you have no way to tell how long you can safely wait before putting on your mask. Without enough oxygen, you eventually die.

So by not putting on the mask, you are risking death. What is the benefit of waiting to put on your mask?

Airlines operating under FAA regulations are required to carry certain amounts of oxygen, depending on the flight. FAR 121.333 covers the requirements for oxygen supply during an emergency descent.

For airliners certified to FL250 and below, they must carry 30 minutes of oxygen for 10 percent of passengers, but only if they can safely descend to 14,000 feet in 4 minutes.

If they cannot safely descend, or if the airplane is certified above FL250 (as most airliners are), there must be at least 10 minutes of oxygen for all passengers, and enough for 10 percent of passengers for the duration of flight with cabin altitude between 10,000 and 14,000 feet. //

At high altitude, the time for useful consciousness is measured in seconds. Pilots are trained to take on the mask immediately when the alarm goes off.

The problem of your approach lies in two uncertainties:

Uncertainty of cabin pressure. Unless you happen to have carried a altimeter with you, of course.
Uncertainty of the oxygen level in your blood. Prolonged hypoxia may cause permanent brain damage.
For your reference, the time of useful consciousness at FL350 is 30 seconds only. If it was a rapid decompression, then the fog which formed instantaneously may have obscured your vision for a good 10 seconds. Granted, at FL150 you'd have 30 minutes. But you wouldn't know. And most passengers simply wouldn't have known the aircraft's attitude the moment it happens. It is simply too risky (for both pilots and passengers) to wait while oxygen supply is available. //

it's important to understand that 100% oxygen at 11 km is possible because pressure is still 22 kPa, greater than the physiological minimum of 16 kPa. If it was below 16 kPa (e.g. at 13 km), even if this 100% O2 supply was in excess for our body needs, it wouldn't be transferred to our blood without increasing its partial pressure to 16 kPa, either by providing more oxygen, or adding another gas to the same quantity of oxygen. Hence at 13 km a pressurized mask would be necessary.
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mins Commented Dec 27, 2016 at 2:23

@mins, yes, above certain altitude even 100% O₂ won't help, but adding other gasses won't change anything, because what matter is that partial pressure of oxygen is at least ~14 kPa (You need 11.6 kPa more O₂ than CO₂ to displace the later from the hemoglobin, plus a bit more for the process to be sufficiently efficient. Exhaled air has around 14.5% of oxygen and that is still plenty for mouth-to-mouth resuscitation.). Total pressure only matters to prevent excessive drying above the Armstrong limit, that pressure is 6.8 kPa (18–19 km; then you need full pressure suit).
– Jan Hudec Commented Dec 27, 2016 at 11:10

ZFS is the last word in the filesystem period. Many administrators are confused about using it – because ZFS is more than a filesystem. It introduces many new concepts. This blog’s mission is to bring ZFS to more homes/companies and show that we don’t need any other filesystem.

The ZedFS gathers information and tutorials about ZFS. If you are curious about ZFS, this website will become your home.

Ok, but why ZedFS?

There is an endless discussion if we should pronounce ZFS as ZeeFS or ZedFS. The debate is so hot that even Michael W Lucas and Allan Jude (the authors of the FreeBSD Mastery: Advanced ZFS) disagreed on how we should pronounce ZFS. Because of that, there is a Canadian version of the “ZedFS FreeBSD Mastery.” (The story of the book). If you are from the ZeeFS camp, then ‘ed’ in the blog’s name is from EDucation.

In traditional file systems we use df(1) to determine free space on partitions. We can also use du(1) to count the size of the files in the directory. But it’s different on ZFS and this is the most confusing thing EVER. I always forget which tool reports what disk space usage! Every time somebody asks me, I need to google it. For this reason I decided to document it here – for myself – because if I can’t remember it at least I will not need to google it, as it will be on my blog, but maybe you will also benefit from this blog post if you have the same problem or you are starting your journey with ZFS.

The zfs list command provides an extensible mechanism for viewing and querying dataset information. Both basic and complex queries are explained in this section.

For one of my datasets zfs list and df show significantly different used numbers: //

Okay, zfs list -o space reveals that it’s (a) snapshot(s):

zfs list -t snapshot myPool/myDataset

For the life of me, I really don't understand why it is in our interests to fund research at foreign universities using federal funds. Research funding is a zero-sum affair. Doling out $386 million to Australian universities means that money will not be available for funding opportunities for American scientists or world-class scientists living in other countries who want to come to America. We should've learned the folly of pushing our research dollars into foreign universities where we can't control what goes on with our Wuhan Institute of Virology tragedy.

Pete Hegseth @PeteHegseth
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Since “Judge” Reyes is now a top military planner, she/they can report to Fort Benning at 0600 to instruct our Army Rangers on how to execute High Value Target Raids…after that, Commander Reyes can dispatch to Fort Bragg to train our Green Berets on counterinsurgency warfare.

The Washington Times @WashTimes
U.S. District Judge Ana C. Reyes orders Pentagon to allow transgender troops, calls Trump ban ‘unabashedly demeaning’

https://trib.al/FxJRjiz
Image
3:29 PM · Mar 22, 2025 //

In my view, the bottom line is that no one has an inherent right to serve in the Armed Forces. When the person suffers from a diagnosable mental illness and requires daily infusions of hormones and other drugs as well as surgery at government expense to live their best fantasy life, they shouldn't be allowed near weapons, ammunition, or explosives. From what we've seen of the impact of transgender "women" on women's athletic teams, you'd have to be a moron not to think they would have a much more deleterious effect while living in close quarters in barracks or deployed.

It is easy for Reyes to make the decisions she's made so far because she has never served in the military and will never have to live with the consequences of her actions.

For many of us, memories of our childhood have become a bit hazy, if not vanishing entirely. But nobody really remembers much before the age of 4, because nearly all humans experience what's termed "infantile amnesia," in which memories that might have formed before that age seemingly vanish as we move through adolescence. And it's not just us; the phenomenon appears to occur in a number of our fellow mammals.

The simplest explanation for this would be that the systems that form long-term memories are simply immature and don't start working effectively until children hit the age of 4. But a recent animal experiment suggests that the situation in mice is more complex: the memories are there, they're just not normally accessible, although they can be re-activated. Now, a study that put human infants in an MRI tube suggests that memory activity starts by the age of 1, suggesting that the results in mice may apply to us.

Recovering from measles does not protect against cancer or any other disease besides measles. In fact, a measles infection has the ability to wipe out immune responses built up against other infections—a phenomenon called immune amnesia, driven by the destruction of memory T- and B-cells. This leaves people who recover from the measles virus more vulnerable to all other germs.

This is not the only severe risk of measles. In addition to neurological and respiratory complications from measles infections, which can demonstrably turn deadly, measles can cause subacute sclerosing panencephalitis (SSPE), a fatal neurological condition that can flare seven to 10 years after a measles infection. //

Before the development of measles vaccines, the virus infected 3 to 4 million people each year, sending an estimated 48,000 to the hospital. About 1,000 developed brain swelling and 400 to 500 died.

Two doses of MMR vaccine are 97 percent effective against measles, and the protection is considered lifelong.

Now an 11th-grader, Gallagher was back on the track for a Portland Interscholastic League meet at the athlete's home track, where Gallagher was spotted blowing out the competition, especially in the 400M, where the athlete finished more than seven seconds better than the rest of the field. //

There's a great way to end this. It will be painful and unfair for a time, but no less unfair than what's happening now. Every girls' team that faces a team with a male member should walk off the field. Every girl on a team that has a male member should walk away. Refuse to play the game. Refuse to dignify this by participating. Refuse. Enough is enough. This may well be the only way this hideously unfair practice is ended for good.

The main difference between Tailscale and WireGuard is that WireGuard is a self-hosted VPN server, while Tailscale adds user authentication and device management to the WireGuard VPN Protocol. Tailscale also relies on cloud servers for authentication and connection, while WireGuard is fully self-hosted and only relies on your private server.

Before looking at Tailscale vs. WireGuard more in-depth below, I want to explain exactly what they both are and how they function.

What is Tailscale?
Tailscale is a VPN service that utilizes the WireGuard Protocol. Tailscale allows you to easily create a VPN tunnel with absolutely no port forwarding. For users who have a CGNAT or simply do not feel comfortable port forwarding, Tailscale is one of the easiest ways to configure a VPN tunnel.

It’s also important to know that while Tailscale utilizes the WireGuard Protocol, it does not function the same way that WireGuard does. While they utilize the exact same point-to-point encryption, using Tailscale requires the Tailscale network to be accessible.

Tailscale is a zero-configuration VPN solution that uses WireGuard, an open-source VPN protocol. It focuses on providing an easy-to-use and configure management interface for the WireGuard protocol.

Tailscale is different than WireGuard in many ways, but it’s a better comparison to ZeroTier than WireGuard due to the way that it’s set up and configured, as well as its functionality. //

ZeroTier is a software-defined networking application that allows devices to be connected over a global network with minimal setup and configuration. It’s designed to function similarly to a local area network (LAN) environment, making it seem like all devices are connected to the same network even if they are physically located in different parts of the world.

Ryan Maue
@RyanMaue
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Greenpeace hit with $667 million judgement.

"...massive financial blow to the group that environmentalists say could chill future climate advocacy" Show more
5:56 PM · Mar 19, 2025. //

However, “Midwestern Burning Man” was no peaceful protest but a transition state to the domestic-terror style ‘advocacy’ eco-extremists are now targeting Tesla with.

This judgement is being celebrated by “normies” and, hopefully it will actually chill the destruction of private property and violence-based intimidation tactics that have been adopted by Marxists/socialists power-mongers parading as “climate advocates”. //

Hodge | March 20, 2025 at 9:28 am
Greenpeace protestors at the pipeline were totally and solely concerned about protecting the environment – NOT.

“On February 22, 2017, the protest site was cleared. Although many left voluntarily, ten people were arrested. On February 23, National Guard and law enforcement officers evicted the remaining protesters. Thirty-three people were arrested. After the protest site was abandoned, sanitation crews cleared garbage from the protest; this included abandoned cars and human waste. Also abandoned were 12 dogs. North Dakota Department of Emergency Services estimated that about 21 million pounds of garbage was removed; the cost of cleaning up the protest site was about $1 million. ”

Napoleon is master of Europe. Only the British fleet stands before him. Oceans are now battlefields. And a moderate box office success from 2003 has become an unlikely streaming favorite, a poster child for the kind of movies Hollywood doesn’t make anymore, and a beacon of positive masculinity.

That would be Master and Commander: The Far Side of the World, director Peter Weir’s adaptation of the historical seafaring novels by writer Patrick O’Brian. Set inside the hermetically sealed world of the HMS Surprise, an early 19th-century British Royal Navy frigate, the movie stars Russell Crowe—fresh off Gladiator and A Beautiful Mind—as Jack Aubrey, the bold, daring, and conspicuously ponytailed captain. Paul Bettany plays Dr. Stephen Maturin, the ship’s surgeon, an erudite naturalist, and Captain Aubrey’s BFF.

If you kidnapped a hundred of Hollywood’s top minds and forced them to work around the clock, they could not engineer a more exquisite Dad Movie. Though Master and Commander is ostensibly about the Surprise sailing to intercept a French enemy warship, the battle scenes, exhilarating as they may be, are few and far in between. The bulk of the film—and the heart of its charm—is instead a meticulous rendering of daily life at sea: the monotony of hard labor, the palpable threat of scurvy, the dirty-faced sailors who sleep in close quarters and grin through yellowed teeth. (You know it smells crazy in there.) Even better? All the screen time devoted to close conversations between Aubrey and Maturin, and their two-dude violin and cello jam sessions. You come away with a sense of satisfaction at their accomplishments and camaraderie, and just a bit of longing over a bygone way of life.

But that low-key intimacy was confounding to audiences expecting the next Gladiator, and the film’s enduring popularity was not obvious when it was first released. Gladiator and A Beautiful Mind each won Best Picture, and Crowe nabbed a Best Actor Oscar for the former. Though Master and Commander was nominated for 10 Academy Awards, Lord of the Rings: Return of the King swept the show. Master and Commander ended up as the 33rd highest-grossing movie of 2003, three spots behind Legally Blonde 2: Red White & Blonde.

Twenty years after it was released in theaters, Master and Commander has found a new life on the internet, simultaneously the subject of memes and sincerely beloved by a certain type of guy (gender neutral). So why does the movie, which is streaming on HBO Max, suddenly have such a grip on the public imagination? One might initially think that it’s a matter of ironic distance—after all, this is a movie about the stodgy British navy, where every single character is a man. “The hot new bachelor party activity is napoleonic era naval gunnery exercises. The boys hooting and hollering as they drink grog firing three broadsides in two minutes,” reads one tweet. Another imagines a scenario in which several more Master and Commander films are announced to the world, Marvel and DC style.

It’s also just fun to argue about online. Even Russell Crowe got into the mix, responding to someone who called the film boring. But while posting about Master and Commander is popular with an irony-adjacent crowd, the love for it is all sincere. Many of the film’s most vocal fans are in their thirties. If they originally saw it in their tween or teen years, their relationship with the movie only deepened as they grew older. //

Any nostalgia stirred up by Master and Commander is also nostalgia for a different era of Hollywood. This sort of richly detailed, big-budget historical epic rarely gets a chance in today’s movie landscape. And even if the action isn’t the point, the battles absolutely kick ass, using practical effects that would probably be weightless CGI these days. (They bought a ship in Rhode Island and sailed it through the Panama Canal and a hurricane to a six-acre filming tank in Mexico!)

Nando Vila, the head of studio at Exile Content Studio, told me, “I think why a lot of guys are liking it now is because Aubrey is so charming and swashbuckling and swaggery. You believe that all those sailors are into Lucky Jack and they'll follow him to the far side of the world. You don't see that kind of brawny, ‘We're just going to go to the far side of the world. Who's with me?’—that’s not a movie that gets made anymore.”

Tom Rothman, the current chairman of Sony’s Motion Picture Group, was the chairman and CEO at Fox when Master and Commander was released. The film was his personal project: a longtime fan of the books, he had been attempting the project for 15 years. “I had to become the chairman of a major motion picture studio before I could get it made,” he told me.

“Why the books, I believe, endure is because they combine the epic and the intimate. They have epic action and daring in them,” Rothman said. “And I'm like any guy. I love that shit. ‘Oh man, they're going to take that ship’ and all that stuff. That's great. Right? But they're also very intimate and personal. They combine the epic and the intimate, and that's what great historical movies do.”

And though Master and Commander may be a film set in 1805 and made in 2003, its themes are eternal.

“It's about how men (and boys) behaved in that time and circumstance,” director Peter Weir told me in an email. “How they understood concepts like 'duty' and 'courage'. Perhaps that has some relevance today. Times change, and with them fashions, but some things remain imperishable. This film touches on those imperishables.”

Every year, nearly 1 million new citizens are welcomed into the United States through naturalization ceremonies, all of whom must pass the American citizenship exam by answering 6 out of 10 questions correctly.

While 90% of legal immigrants pass the exam, only 36% of Americans can pass it!

an easy way to sew buttons on shirts

As the Department of Government Efficiency (DOGE) looks to slash waste and correct inefficiencies, one DOGE adviser revealed it's "hard to really grasp the scale" of problems facing the IRS.

"A huge part of our government is collecting taxes. We cannot perform the basic functions of tax collection without paying a toll to all these contractors. We really have to figure out how to get out of this hole. We're in a really deep hole right now," DOGE representative Sam Corcos said on "The Ingraham Angle" Thursday.

Department of Government Efficiency @DOGE
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There is a pattern across all agencies where IT “modernization” contracts do not pay for outcomes/performance; instead, they pay for time. Therefore, the incentive is for contractors to “never finish,” resulting in incredible waste.

As an example, IRS modernization started in 1990 to be delivered in 1996. Today, the work is not complete and the contractors say it’s still 5 years away. 29 years behind schedule and ~$15b over budget. Everyone loses, except the government contractors.

This must change. This week, the IRS froze ~$1.5B in modernization contracts, none of which have any effect on tax filings. All of those contracts will then either be cancelled or the contract terms will be changed to pay-for-performance.
9:25 AM · Mar 21, 2025 //

When the media omit the facts that matter most, it’s clear that they are more interested in undermining the Trump administration in the court of public opinion than in informing the public about the very real threats America faces.

The Supreme Court has become a paper tiger, failing to hold defiant lower courts accountable when they make rogue decisions. //

Lower court federal judges across the country are standing athwart the American people’s will to allow the Trump administration to cut government programs and deport violent gang members from the country. But these unelected judges have a long-running pattern of clinging to their status quo, even in defiance of the Supreme Court, because the high court refuses to rein them in.

The Supreme Court has the responsibility to make sure its subsidiary courts follow its directives — often by taking more cases, and making their precedent unambiguous. Arrogant, active, and open defiance on some of the most important issues, however, has been the norm from these lower courts for years, and a majority on the high court has persistently refused to stop them. //

The Court’s majority again refused to take a case wrongly decided by lower courts, when the Biden administration attempted to fine a Medicare-funded work-around for Dobbs, forcing hospitals in Idaho, which had outlawed almost all abortions, to perform them anyway.

“Shortly before Idaho’s law took effect, President Biden instructed members of his administration to find ways to limit Dobbs’s reach,” Alito wrote in a dissent for Moyle v. United States. “Apparently, the Court has simply lost the will to decide the easy but emotional and highly politicized question that the case presents. That is regrettable.”

It’s not just abortion, it’s Second Amendment rights as well. Lower courts repeatedly waged war against DC v. Heller, the Supreme Court precedent that struck down a law that banned handgun ownership in Washington, D.C., and clarified that the Second Amendment does not just protect a right to self defense for militia purposes.

In a 2018 case that would have allowed the Court to enforce its own precedent, the Court ran away, and had done so for years, Thomas wrote in yet another dissent slamming lower courts for defying the high court.

“Our continued refusal to hear Second Amendment cases only enables this kind of defiance. We have not heard argument in a Second Amendment case for nearly eight years … If this case involved one of the Court’s more favored rights, I sincerely doubt we would have denied certiorari,” Thomas said before listing other rights that the Court would have taken cases on. “The Court would take these cases because abortion, speech, and the Fourth Amendment are three of its favored rights. The right to keep and bear arms is apparently this Court’s constitutional orphan. And the lower courts seem to have gotten the message.” //

The Court used to enforce its precedent, like when lower courts attempted to defy Brown v. Board of Education and its mandate to racially integrate schools. It used to do it because it has always been part of the job — precedential decisions are not ‘one-and-done’ adventures. They will need clarification, parameters set, or clarity for lower courts to tell them the high court meant what it said.

At least one federal judge, James C. Ho of the Fifth Circuit Court of Appeals, has publicly diagnosed at least part of the problem with the court refusing to take cases: A debilitating lack of fortitude among a vast array of federal judges.

In a 2023 speech at the Heritage Foundation, Ho said many federal judges are afraid to make tough decisions, or take tough cases, because they are afraid of public backlash for making the right decision:

If you plan to be faithful to the Constitution in every case, no matter how unpopular that may be, gold stars are not in the cards for you. But that’s the job. Judges don’t swear an oath to uphold the Constitution part of the time: We swear an oath to uphold the Constitution all of the time.

If you’re an originalist only when elites won’t be upset with you—if you’re an originalist only when it’s easy — that’s not principled judging. That’s fair-weather originalism. We’re not binding ourselves to the text if we only follow it when people like the result.

“When you look at the résumé of a typical federal judge, you often see a bunch of fancy credentials,” Ho added to the argument in a 2024 piece for the National Review. “People who have devoted their whole lives to collecting gold stars tend to be motivated by one overarching objective: getting more gold stars. If that’s what drives you, then the threat of public scolding can be a powerful motivator.”

The “booing of the crowd,” Ho said, “is not going away anytime soon,” and if judges cannot handle it, they should probably find other work.

At what point does judicial review turn into judicial rule?

This problem isn’t just about these issues or executive power — it’s about the broader politicization of the judiciary. When a judge blocks a policy because he personally opposes it, rather than because it violates the Constitution, he is no longer functioning as a neutral arbiter. //

Even the Supreme Court has recognized the dangers of this judicial overreach. In Trump v. Hawaii (2018), Chief Justice John Roberts warned lower courts that they do not have the authority to micromanage national security decisions made by the executive. Yet lower courts continue to ignore that warning, issuing nationwide injunctions based on political discomfort rather than constitutional law.

The media will cast Trump’s decision to ignore Boasberg’s ruling as reckless, lawless, or authoritarian. But what’s truly reckless is allowing the judiciary to continue seizing power it does not have. There is precedent for presidents pushing back against judicial overreach. Abraham Lincoln ignored a Supreme Court ruling in 1861 when Chief Justice Roger Taney attempted to block his suspension of habeas corpus during the Civil War. Andrew Jackson famously refused to comply with a Supreme Court decision in Worcester v. Georgia, arguing that the executive branch — not the judiciary — was responsible for enforcement. Both of those decisions were controversial. Both were necessary.