Intriguing black hole research

A paper came out in January talking about that old black hole chestnut - the breakdown of physics inside of them, and the cosmic censorship idea that we'd never know about it anyway.

Here's an explanation of the paper from some physics site I'm unfamiliar with, and I'll extract the first couple of paragraphs:

Is the future predictable? If we know the initial state of a system exactly, then do the laws of physics determine its state arbitrarily far into the future? In Newtonian mechanics, the answer is yes. Similarly in electromagnetism: if one knows the initial state of the electric and magnetic fields exactly, then Maxwell’s equations determine their state at any later time. In quantum mechanics, if the initial wave function is known exactly, then Schrödinger’s equation can be used to predict the wave function at any later time. However, new research by Vitor Cardoso from the University of Lisbon, Portugal, and colleagues [1] suggests that this predictability of the laws of physics can fail in general relativity. The researchers find that it might be possible for a star that undergoes gravitational collapse to form a black hole containing a region in which physics cannot be predicted from the initial state of the star.

General relativity asserts that spacetime is dynamical, with its dynamics dictated by Einstein’s equation. Just as the initial state of a particle is specified by its position and velocity, an initial state for spacetime is specified by the geometry of space at some instant of time, as well as by its rate of change. Given such initial data, a fundamental theorem in general relativity [2] states that there is a so-called maximal Cauchy development. This is the largest spacetime that is uniquely determined by the initial data. But is it all of spacetime? In other words, could the maximal Cauchy development be a subset of a larger spacetime? By definition of the maximal Cauchy development, this larger spacetime could not be predicted from the initial data. This scenario would represent a failure of determinism: one would not be able to use the initial data to predict the state of spacetime arbitrarily far into the future.

 Another article trying to explain it (and I suspect, not as accurately) is here.

One thought that is not mentioned in either paper - could this potentially tie in, in any way, with the idea that our universe is actually inside of a black hole?    If so, could it be a way in which our universe is not deterministic?   Just a thought....

Olde time surgery

Everyone gets a laugh out of historical tales of ridiculous self surgery, don't they?   From a review of a book that sounds like gory fun:

Arnold van de Laar, the Dutch surgeon, opens this fascinating history of surgery with the tale of a 17th-century blacksmith who had been so sorely disappointed with the botched operations performed by the scalpel-wielders of his day that he took matters into his own hands and cut a 4oz stone from his own bladder while his wife was at the shops.

Today, with decent hygiene, bladder stones are rare, but then they were rife. From a simple urine infection, they would grow like pearls inside oysters, pressing on the sensors that prompt urination while impeding the act. Hippocrates, the father of medicine, would have counselled any doctor against attempting to remove one, as the operation was more likely to kill the patient than the stone itself. But the pain drove sufferers to seek the relief offered by professional "cutters", even though the procedure had a 40pc mortality rate.

It was only after two cutters had failed to remove 30-year-old Jan de Doot's stone that he decided to do it himself. He made a surgical knife in his own forge, then instructed his apprentice to hold his scrotum out of the way as he made three, deep horizontal slits in his own perineum, and extracted a stone larger than a chicken's egg. De Doot succeeded where the experts had failed, and became famous for his extreme DIY.

Um, I assume there was a mirror involved too?  Might have to buy the book to find out...

Update:   Oh - Wikipedia has an entry on the self-surgeon, who is obviously better know than I kenw.   The story first appeared in a book in 1672!    I still don't understand how this surgery was done, though.  And the assistant scrotum holder in the original is apparently his brother, although it might be that his brother was also an apprentice, I suppose...

Oh, please

I also can't stop reading breathless, ecstatic commentary on how Black Panther is going to change everything.  Latest example, in Slate:  What Black Panther could mean for the Afrofuturism Movement. 

Apparently, watching fantasy physics about fantasy materials is going to encourage black kids to get into STEM.    OK, I might have to concede Star Trek might have had an influence on making science education cool, but Marvel level fantasy physics having the same effect?    Can't see it.

And most of the article just reads like fantasy to me.

Hard to avoid watching the car wreck

That's how I feel about reading about the Right wing reaction to the latest mass shooting in America - it pretty much nauseates me as offensive both to reason and emotion, but can't stop looking.   

The latest:   as Jason Wilson writes in the Guardian, they're attacking the very idea that teenagers who survive a school shooting should be paid any attention.   Because, you know, teenagers.   Even Ben Shapiro, barely out of braces himself, is taking that approach.  

The line between emotional and rational decision making is, as it happens, in the matter of gun control, one where the emotional does deserve extra weight.   Because you can rationalise away legislative responses to almost any tragedy if you want to, and gun rights nutters are highly motivated to do so.  The easiest way - routinely deployed - make the perfect  the enemy of the good.    It's a rational argument in its own way - you need emotional clout to say "stop deploying what you think is a 'rational' response to repeated death and mayhem, when there are sensible things that could be done."  

Second point:  Trump's response is only to call again for banning bumpstocks - not even implicated in the latest killing.    At this rate, he'll contemplate increasing the age for buying AR-15s after another 6 mass shootings by teenagers.

Third point:  a lot of discussion happening about how the attitudes of under 35's towards gun control is not as "liberal" as you would expect.    Vox has a good article about it, but one thing I reckon would be important about this - the way polling is conducted on this issue is, I suspect, particularly open to uncertainty, given the speed with which recent shootings drop out of the public mind, and the very vagueness with some of the terminology such as "gun control".    Hence it is an issue where politicians are entitled to take a lead and not just try to work out a response based on imprecise readings of what steps a majority would approve.   But of course, politicians on the Right are the least likely to want to make any effort at all.  

American gun paranoia at work

I had heard of this before - the guns rights organisations in the US are paranoid about the idea of the government having an easy to search, computer based system for tracing ownership of guns used in crimes.  The result - a mountain of paper and microfiche records that are searched through (surprisingly, sometimes still successfully.)

This great national embarrassment - borne of simple paranoia that if the government knows who has a gun, they'll come and take it off you - is explained in detail, with photos, here at GQ (of all magazines.)  

Call for assistance

Can someone with time and better photo editing skills than me please convert this using Barnaby Joyce and Malcolm Turnbull's faces?:

I guess it has to be Barnaby on the left.   Julie Bishop is in the background...

OK, well my pathetic, hurried abilities have to go on display again:

King t'Urnbull confronts Killmarriager

 

Just not getting this...

I don't want to go on too much about the chronic over-rating of Black Panther, but I did forget to mention in my review that I didn't even find it visually very interesting.  Hence comments like this one, to be found on Wired, leave me gobsmacked:

Visually, no other Marvel movie has ever come close to Black Panther—the lush Wakandan landscapes, the vibrantly colored costumes, even the wearable tech was beautiful. And that moment where the Royal Talon Fighter dips below the veil and we get an aerial look over the Golden City? Jawdropping.

Um, convincing looking fantasy cities, either functioning or dystopian, are a dime a dozen in movies these days, Marvel made or not.   In fact, I was distinctly underwhelmed by the first appearance of the Wakanda city - it had African touches, but seriously, it was nothing groundbreakingly impressive, which the lead character had led us to expect.  

And as for the interior of the vibranium mine where the (underwhelming) climatic fight between the two main characters took place - it was one of those examples of complete CGI background gone too far, and looking unconvincing for it.    A bit like the climatic setting of the last Guardians of the Galaxy movie, now that I think of it.  Completely fake backgrounds have a way of making me too aware that the fighting is happening in front of green screen, and as such, there is no tension that they might fall off that (obviously unreal) high platform, for example.  

Angry woman

I don't usually bother watching QandA on ABC anymore, but it happened to be on in the background last night, and I noticed when an angry aboriginal woman started going on in a shouty way about sovereignty not being conceded, the government should shut up and list to aboriginal voices, stop failing them dismally, and spend more money on them, etc.

It seems to me, following the Australia Day marches, that there is something of a revival of aboriginal "sovereignty talk" amongst aboriginal activists.   Has this come via some influential adviser, or something?    Because, after Mabo, I thought all mainstream activists had given up on this type of talk.   But it seems to be back with a vengeance.

And I can't see how it is going to help.

Last night's activist, Shareena Clanton, an actor who I have not heard of before, at one point made the point that it was aborigines themselves who were making the change to improve themselves, and then listed a bunch of relatives who were educating themselves and getting good jobs.   

Well, good.   But sort of undercuts the "it's outrageous that you're not spending enough money on my people" line a bit, doesn't it?

Aboriginal advocacy is becoming more strident, but I suspect it could do with a bit more plain speaking about the practical difficulties of dealing effectively with (in particular) disadvantage for remote communities with little economic tie to society....

Don't mention the war - still

Victor Venema, a Dutch climate scientist with a blog who works in Germany, has a short post up noting that Germans are treated by other nationalities as if they personally started World War 2.  And many Germans feel guilt about it, no matter how many decades after the war they were born.

I didn't really appreciate that this was still such an issue, but apparently it is...

Dark side hidden

Interesting story at Hot Air, about the couple who Florida shooter Nikolas Cruz was living with after his adoptive mother died.

Sounds like they were good to him and tried to be very responsible about his guns.

A few lessons from this can perhaps be drawn:

*  Better background checks may have had no effect
*  An FBI field officer may well have been satisfied that he wasn't a real threat despite saying stupid things on social media.
*  What may have had an effect - his not being able to own assault rifles at all, especially at his age and given his mental issues which people close to him did not realise were so deep.

Trendy drug taking

So, someone at Vox writes about his ayahuasca taking retreat at Costa Rica.

It sounds like a rather expensive, New Age-y sort of place, with 4 nights of drug taking, with lots of crying (and puking) and apparent insight which nonetheless seems to have worn off after a few weeks back in normal land.

I remain unconvinced that the benefits some people feel from the experience are worth it.   While open to the idea that people with certain specific psychological issues might benefit from controlled usage of certain psychedelics, my overall impression is the experiences usually give an emotional insight that is later seen as a false dawn.   

The Right Wing hand wave machine

Wow.  PJ Media has an article "When Will We Have the Guts to Link to Link Fatherlessness to School Shootings?" 

Geez, Cruz's adoptive father died of a heart attack a few years ago.   His adoptive mother died in November.    The evidence is she tried to get police to help control her son - if so, she was presumably well intentioned.   (I have seen some idiot on twitter say that it always comes down to bad parenting.)

So seems a tad pointless to be raising that as an issue now, unless the proposal is that loners with no father in the house can't have guns.  Yeah, sure, how likely is that the real intention of the article?    And anyway, what about the mother who has guns in the house - which shooting was it where the guy used his Mom's (legal) guns?  There are so many it's hard to keep count.

This and that

*   Given certain articles appearing in the Right wing media, it would appear a vague hope that the Florida shootings may actually result in some legislative changes for gun control.   I bet it will not extend to banning the sale of military looking semi-automatics, though.   The fantasy that the gun nuts of American need to be ready to save the country from invasion, or the next Democrat President, is too strong.

*  Yes, the Left wing does take too much time taking offence, and this article at The Atlantic gives a good example.  So does Mary Beard, who is a perpetual target of alt.righters, but also found herself on the receiving end of some Lefty attack.   She can't win.    Social media, especially Twitter, with its required compression of thoughts leaving little room for nuance, is so often to blame.   The Professor should probably stay off it.

*  In one of the very, very few critical readings of the politics of Black Panther, someone writing in the Boston Review has a problem with how the conflict in the movie is resolved:  BIG SPOILER BELOW, if you intend seeing it:

By now viewers have two radical imaginings in front of them: an immensely rich and flourishing advanced African nation that is sealed off from white colonialism and supremacy; and a few black Wakandans with a vision of global black solidarity who are determined to use Wakanda’s privilege to emancipate all black people.

These imaginings could be made to reconcile, but the movie’s director and writer (with Joe Cole), Ryan Coogler, makes viewers choose. Killmonger makes his way to Wakanda and challenges T’Challa’s claim to the throne through traditional rites of combat. Killmonger decisively defeats T’Challa and moves to ship weapons globally to start the revolution. In the course of Killmonger’s swift rise to power, however, Coogler muddies his motivation. Killmonger is the revolutionary willing to take what he wants by any means necessary, but he lacks any coherent political philosophy. Rather than the enlightened radical, he comes across as the black thug from Oakland hell bent on killing for killing’s sake—indeed, his body is marked with a scar for every kill he has made. The abundant evidence of his efficacy does not establish Killmonger as a hero or villain so much as a receptacle for tropes of inner-city gangsterism.

In the end, all comes down to a contest between T’Challa and Killmonger that can only be read one way: in a world marked by racism, a man of African nobility must fight his own blood relative whose goal is the global liberation of blacks. In a fight that takes a shocking turn, T’Challa lands a fatal blow to Killmonger, lodging a spear in his chest. As the movie uplifts the African noble at the expense of the black American man, every crass principle of modern black respectability politics is upheld.

In 2018, a world home to both the Movement for Black Lives and a president who identifies white supremacists as fine people, we are given a movie about black empowerment where the only redeemed blacks are African nobles. They safeguard virtue and goodness against the threat not of white Americans or Europeans, but a black American man, the most dangerous person in the world.

Actually, I think he has a point.   Surely the better way to resolve this would be to have Killmonger either repent, or kill himself either deliberately or accidentally  (as an example of radical violence, no matter how well intentioned, consuming itself.)  

Maybe when all the hype has died down, this type of re-assessment of the dubious lessons of the film will become more widely accepted.  At the moment, it is all swept away by some strange, very peculiarly American, I reckon, excitement about an all black movie.

*  The Catholic Church's slow moving crisis of revised understanding of its authority and conscience (its been going on since the 1960's) is getting very close to the top when an American Cardinal is making statements as reported here.

A couple of questions about the FBI (and the appalling Republicans)

With the news this morning that the FBI got a very specific tip off about concern over the guy who went and shot up the Florida school (and the information did not get passed down to their Florida office), I am curious about two things:

*  Just how many tip offs are received each year in a nation so brimming with private fire arms? 

*  What can the FBI do anyway, unless the guy under scrutiny turns out to have an illegal fire arm or to be so nutty he can be forced into immediate psychiatric treatment?

I see that at least partial answers are at this article at PBS:

FBI assessments are routinely opened after agents receive a tip, which could be sparked by something as simple as noticing odd activity in a neighbor’s garage or a classmate’s comments. Agents routinely face a challenge of sifting through which of the tens of thousands of tips received every year — and more than 10,000 assessments that are opened — could yield a viable threat.

And as to what they can do - as I expected, often it will turn out to be "nothing":

FBI guidelines meant to balance national security with civil liberties protections impose restrictions on the steps agents may take during the assessment phase.

Agents, for instance, may analyze information from government databases and open-source internet searches, and can conduct interviews during an assessment. But they cannot turn to more intrusive techniques, such as requesting a wiretap or internet communications, without higher levels of approval and a more solid basis to suspect a crime.

“It’s a tricky situation because sometimes you get information regarding individuals and they may be just showing off, blustering,” said Herbert Cousins Jr., a retired FBI special agent in charge.

A vague, uncorroborated threat alone may not be enough to proceed to the next level of investigation, according to Jeffrey Ringel, a former FBI agent and Joint Terrorism Task force supervisor who now works for the Soufan Group, a private security firm.

Many assessments are closed within days or weeks when the FBI concludes there’s no criminal or national security threat, or basis for continued scrutiny. The system is meant to ensure that a person who has not broken the law does not remain under perpetual scrutiny on a mere hunch —- and that the FBI can reserve its scarce resources for true threats.

Had he had pledged his allegiance to the Islamic state, for example, investigators might have had enough evidence to proceed with a more intrusive probe.

Tips like the one that came in about the Florida gunman are among countless complaints that come into the FBI daily with varying degrees of specificity.

“How many of these do you expect the FBI to handle before it becomes the Federal Bureau of Complaints,” said Hosko. “They could spend their entire workforce tracking down internet exchanges that never going to go anywhere.”

And, as the article earlier says, some recent high profile killers were looked at by the FBI, who decided nothing could be done:

In the last two years, a man who massacred 49 people at an Orlando nightclub, another who set off bombs in the streets of New York City and a third who gunned down travelers at a Florida airport, had each been looked at by federal agents but later determined not to warrant continued law enforcement scrutiny.

Of course, we all know that Trump and Republicans will make big claims about how this Florida killing was the FBI's fault, because it helps in their self serving PR war with the bureau,  and because it provides yet another way to claim mass shootings are about poor enforcement of current laws, despite the fact that so many of them are done with legally purchases assault weapons, or mental health, even going back to decrying liberals for 'de-institutionalisation', as if it would be easy to lock away every loser with a gun collection on mental health grounds.

Amongst other stuff I thought worth reading after the Florida shootings, I liked this piece by James Fallows pointing the finger at the very specific role of Mitch McConnell, old turtle head, on preventing a reasonable set of gun law reforms proposed by Obama after Sandy Hook.

And speaking of Obama, just have a read of this Fact Check piece on the claim that Obama "flip flopped" on gun control.  The short answer is that he didn't, and when you read the quotes from Obama, it's hard not to impressed that he was so consistent and reasonable on the whole issue.   There used to be a moral adult in the office.

And another responsibility avoiding line the Right is now taking - saying that Democrats used to control congress and why didn't they pass control then?   Two points I thought are pertinent:

*   just how much of a good argument is it to say "the other side were too cowardly to risk votes to bring in gun control."   It's pretty much arguing "if they were cowards, we can be cowards too."

*  there have more and more school shootings since then anyway.    The reason for action becomes more apparent, and it's a cop out handwave to say "well they didn't do anything so we won't either."

Update:  look at the information in this tweet going around:

Save me, hat..

So, Barnaby's just given a "get stuffed, Malcolm, I'm not going" press conference, wearing his biggest, cleanest hat by the looks!   Does he think the hat will save him in the bush?

Looking at twitter, his support numbers, already low, are just plummeting downwards....

Update:  someone else thought the big hat deserved ridicule, and created this very quickly

About that Black Cat movie..

Just in case people think I've become something of a Marvel fanboy because I saw Black Panther so soon on its release - my son had a free ticket he had to use by yesterday, OK?

And as for the movie - it's one of those cases where the critical reception is more interesting (for how wildly it varies from my perception) than the movie itself.

Look, it's not offensively terrible (no Marvel movie is):  it's just pretty bad.

Even my 17 year son immediately rated it as clichéd;  I don't think he disagreed when I pointed out it was like The Lion King as done by Marvel but without the charm or emotion.

None of the acting is bad, but nor is it worthy of some of the ridiculous over-praise it is receiving, particularly in American reviews.   It has some humour, but not much;  it is too long,  fairly dull in large part, and I even started feeling the head piece of the costume is a bit silly.

But my main criticism - I think the action scenes, particularly at the climax of the film, are terribly directed and over-edited.   They were to me completely unengaging and tensionless, and I would never trust any critic who calls the climax of the movie "thrilling".   (The only other major large scale action set piece - and there are only two in the entire movie - in Busan, Korea, was a little better, but even then the editing gave no sense of continuity in the car chase, and the whole sequence came across as a James Bond piece poorly done by Marvel.)

So, as to the reasons it is getting many rave reviews:   honestly, it's hard to see how it isn't being reviewed under undue influence of its alleged black empowerment (even, black Africa as saviour of the world) theme.   Not that there's anything wrong with black empowerment - God knows I have sympathy for how the community is faring under Trump - but really,  it seemed dubious to me that there should be black pride taken in imagining a modern African technological fantasy land where leadership is still decided by the equivalent of duelling to the death.

I suspect you have to live in America (and be of liberal persuasion, as most reviewers obviously are)  to share in great enthusiasm for the film.   Again, NTTAW with being a liberal reviewer:  readers would know I generally dislike those directors highly praised by Right wing websites.    But here critical judgement has been led astray, I think.   Interestingly, when I check the long list of reviews on Rottentomatoes, two of the mere handful of negative reviews are Australian.    There should be more of that....

Update:  I see the movie is getting some pushback in user reviews at IMDB - but how many of those are genuine and not part of a stupid alt.right organised push, I don't know.  

Take a hint

Turnbull's press conference sounded like an enormous hint to Barnaby to resign.

How humiliating for all concerned that Barnaby is trying to ride it out.

Will he take the hint, or do we have to wait for another story of his private behaviour to come out as confirmed? 

Stupid comments on shootings

Just to get his off my chest:

One of the stupidest things some people say after American school shootings is that the problem is no armed guards/metal detectors at the school.   Um, at the risk of stating the obvious:  schools have long boundaries and (usually) several entrances:  while you can insist that all students funnel into the school at one entry point, just how much money would it cost to turn every single American school into a hard to penetrate high security compound?   Get real:  schools and educational places are always going to be easy places for armed killers to gain access to.   They are also big - just how many armed guards do these people think it would take to stop a dozen dead in one room in a hail of bullets?

And don't get me started on teachers should all be armed too...yes, poor old Mrs Smith who was about to retire should have realised when she became an elementary teacher that by 2018 it would become a job in which paramilitary training was essential.

Oh - and what a disgusting idiot is Jim Hoft (Gateway Pundit), with his immediate rush after every mass shooting to try to pin the killer as an Islamist/Democrat/Left winger, usually relying on material that quickly turns out to be deliberate misinformation or mistaken identity.  He makes me sick. 

Update:  during lunch, I saw some guy on PBS from the local area talking about the plans the school had made to be prepared for such an event.   He said it was very detailed and as well prepared as a school could be.

Also, it may well be that Jim Hoft has his stupid "we must know who this guy would support politically" post 100% wrong in this case.  He's an utter creep.

Rabbit history (and a bit about rats, too)

Ed Yong writes about the great confusion over how rabbits became domesticated.   Apparently, there have been a few science-y urban myths floating around about this for some time (not that I had heard of them before.)  But I also learnt some things about how rabbits have been used:

Archaeological evidence tells us that people in Spain and France were eating rabbits as early as the Epipaleolithic period, between 20,000 and 10,500 years ago. During the Middle Ages, they became a high-status food and people started carrying them across Europe. But it’s hard to pinpoint exactly when this happened because of, as Irving-Pease and Larson note, “the intrusion of rabbits into archaeological stratigraphies.” Translation: It’s hard to know if a rabbit bone came from an ancient rabbit, or a recent one that went digging...

....Rabbits are among the most recently tamed animals, and yet neither history nor archaeology nor genetics can accurately pinpoint when they were domesticated. “There is solid genetic evidence that domestic rabbits are closely related to wild rabbits from France, from which they were mostly derived,” says Miguel Carneiro from CIBIO, who recently did his own genetic study of rabbits. “But the timing, initial motivation, and the underlying process remain poorly understood.”

Larson thinks that’s because people tend to wrongly picture domestication as a singular event. “Everything’s the same, and everything’s the same, and something changes like a bolt from the blue, and now everything’s different,” says Larson. “A lot of our narrative structures hinge on that. But if you’re looking for a moment of domestication, you’ll never find it. It’ll recede from your fingertips.”

Domestication is a continuum, not a moment. Humans hunted rabbits, tens of thousands of years ago. They transported the wild animals around the Mediterranean. The Romans kept them as livestock in structures called leporaria. Medieval Britons kept them in “pillow mounds”—raised lumps of soil that acted as earthen hutches. Later, they used actual hutches. Eventually, we bred them as pets. None of these activities represents the moment when rabbits hopped over the domestication threshold. But collectively, they show how wild bunnies turned into tame ones.

Yong says domestication of animals is hardly ever deliberate, anyway:

The problem is that there’s no solid evidence that humans domesticated anything deliberately (with the possible exception of tame foxes that were bred for scientific purposes). There’s no unequivocal case where humans grabbed a wild animal with the express intent of domesticating it. Instead, for example, it’s likely that scavenging wolves were attracted to human hunts or refuse piles, eventually developing a more tolerant attitude that led to their transformation into dogs. Similarly, mice were attracted to our grain stores, and cats were attracted to the mice. “There is no why to domestication,” says Larson. “That implies a directedness that appears not to exist.”

 I wonder, however, if Yong is overlooking the matter of Jack Black, rat catcher to the Queen, who is credited with taming wild rats into pet fancy rats.   Maybe Yong doesn't consider that pet rats are truly domesticated, but there is perhaps a debate to be had about that.  From a book "Domesticated:  Evolution in a Man-Made World":

Depressing American story of the day

The New York Times depresses us all by explaining that meth is making a big comeback in many parts of the US, after dropping out of the limelight for a few years due to the deaths caused by opioids.   On the upside, there are fewer meth labs;  on the big downside, there's heaps more meth around:

The scourge of crystal meth, with its exploding labs and ruinous effect on teeth and skin, has been all but forgotten amid national concern over the opioid crisis. But 12 years after Congress took aggressive action to curtail it, meth has returned with a vengeance. Here in Oregon, meth-related deaths vastly outnumber those from heroin. At the United States border, agents are seizing 10 to 20 times the amounts they did a decade ago. Methamphetamine, experts say, has never been purer, cheaper or more lethal.

Oregon took a hard line against meth in 2006, when it began requiring a doctor’s prescription to buy the nasal decongestant used to make it. “It was like someone turned off a switch,” said J.R. Ujifusa, a senior prosecutor in Multnomah County, which includes Portland.

“But where there is a void,” he added, “someone fills it.”

The decades-long effort to fight methamphetamine is a tale with two takeaways. One: The number of domestic meth labs has declined precipitously, and along with it the number of children harmed and police officers sickened by exposure to dangerous chemicals. But also, two: There is more meth on the streets today, more people are using it, and more of them are dying.

As for the libertarian "all illicit drugs should be legalised" line, it's hard to see what difference that would make when the drug is dirt cheap:

When the ingredients became difficult to come by in the United States, Mexican drug cartels stepped in. Now fighting meth often means seizing large quantities of ready-made product in highway stops.The cartels have inundated the market with so much pure, low-cost meth that dealers have more of it than they know what to do with. Under pressure from traffickers to unload large quantities, law enforcement officials say, dealers are even offering meth to customers on credit.

Nearly 100 percent pure and about $5 a hit, the new meth is all the more difficult for users to resist. “We’re seeing a lot of longtime addicts who used crack cocaine switch to meth,” said Branden Combs, a Portland officer assigned to the street crimes unit. “You ask them about it, and they’ll say: ‘Hey, it’s half the price, and it’s good quality.’”

Nationally, nearly 6,000 people died from stimulant use — mostly meth — in 2015, a 255 percent increase from 2005, according to the Centers for Disease Control and Prevention.