How does the US use water? (construction-physics.com)
220 points by juliangamble 1d ago 168 comments
Show HN: OS X Mavericks Forever (mavericksforever.com)
383 points by Wowfunhappy 4d ago 173 comments
US to review all 55M visas to check if holders broke rules
45 vinni2 35 8/22/2025, 2:20:27 PM bbc.com ↗
You know why we don't give everyone a full body MRI every year? Too many false positives, too many benign findings that result in unnecessary action, too expensive.
This is the same. It's going to have errors, it's going to find benign things, and it's going to be expensive. It's going to hurt people who fundamentally did nothing wrong.
If it's expensive and hurting innocent people, it sure looks like cruelty is the point.
I've heard many horror stories of bank/brokerage accounts being frozen despite all deposits being legitimate, not to mention not being able to transfer large amounts or not even being allowed to open an account.
Meanwhile crooks somehow manage to have bank accounts in all the big banks without issues.
Point is, the false positive concern is only a concern if you use the old model with the new corpus. Don't do that! That's dumb!
The net effect of MRIing everyone on public health would likely be enormously positive as long as you don't do that.
With the MRI, you don't get back simple dichotomous things, but you get back potential indications. That can be scary - talk about calibration all you want, but if patients see things and start thinking about the big C word there are likely to be a lot of unnecessary biopsies.
The bottom line is that it's possible to imagine a benefit, but it is not reasonable to pretend it's as simple as "just re-calibrate your interpretation of the results!". There's a reason that a lot of thought goes into when to do screening.
This just isn't true. In practice any such screening model can ALWAYS improve with more data—basically because the statistical power goes up and up—up to an asymptote set by noise in the physical process itself.
> That can be scary
Handling that is the job of professionals, is now and will continue to be.
It is extremely reasonable to imagine a benefit! What is doubtful is imagining there wouldn't be one!
I find the line of reasoning in this whole anti-MRI-everyone argument to be bewildering. I think it is basically an emotional argument, which has set in as "established truth" by repetition; people will trot it out by instinct whenever they encounter any situation that suggests it. It reflects lessons collectively learned from the history of medicine, its over-estimation of its own abilities and its overfitting to data, and its ever-increasing sensitivity to liability.
But it is not inherently true—it is really a statement about poor statistical and policy practices in the field, which could be rectified with concerted effort, with a potential for great public upside.
Not that any of this matters at the current price point. But, on a brief investigation, the amortized cost of a single MRI scan is ~$500-800—perhaps 1/5 what I would have guessed!
At least we're still at the stage where they're bothering to find pretext. There is still hope.
Coastal Oregon and coastal Washington can come too.
I have spent more than two and a half years filing forms and preparing paperwork for the U.S. government. I handled everything myself, without any “special” help or legal advice. I simply downloaded the forms from USCIS, filled them out using the required information, and submitted them.
What I can tell you is this: there is a massive market in the United States built on gray-area schemes, semi-legal shortcuts, and so-called expert advice. For example, there are companies charging $30,000 to submit a form that costs only $745 to file. Many “helpers” sell visa “upgrades.” The idea is that you arrive on a tourist visa and then follow a specific sequence of steps to convert it into a green card - something packaged and sold as a premium service for an extraordinary price.
This is a very large and lucrative slice of the pie that most people know little about. Both the U.S. visa process and tax filing system are riddled with gray practices and questionable “solutions.” Too often, the end result is that people are told to outright lie about their visa status or their taxes because they were instructed to do so.
From what I have observed, I would not call these practices outright foolish. Overblown at times? Yes, perhaps. But unnecessary? Not really.
55M is also just a crazy amount of visas for a country with 350M citizens. Especially given that I'd guess that a large amount of people travel to the US on a visa waive program.
PS: This rather useless comment is actually an expression of frustration. We are a population of more than 8 billion. Why are such concepts being tolerated?
Who here would be happy if you invited a guest into your house and they ignored your customs like no shoes in the house or clean up after yourself.
Why should countries be different.
I'm sure you're confident about the ability of your citizens to hold up the nation without any help. I'm not going to argue. I admire all societies and cultures for their unique abilities and achievements. But you would be worried if you knew how much these 'guests' contributed to your nation's greatness across time and across every strata of your society. They built everything from your earliest railroads to your biggest rockets. They man your remotest farms to the top echelons of your administration. You'd be underestimating their importance to your welfare at your own peril.
But forget the guests. I'm worried about you people too. Nations treat the visas they issue and even asylum requests with great respect. The guests are given almost all the protections as citizens - only the right to influence the governance is denied. But that situation has changed rapidly recently. Not only are the legal guests being abused, the treatment is gradually being extended to legal citizens, with the attempts to cancel birthright and naturalized citizenship. Two measures are extremely concerning - many of the deported immigrants had no criminal records anywhere. And citizens like the 4 year old cancer patient were deported by putting their immigrant parents in an impossible situation. At this rate, how long till they start applying it to citizens like you? Never forget what someone said about 'home growns'. Clearly, your conduct is not what defines your standing. Are you sure you're on the right side in this regime's eyes?
I could taunt you for your confidence, which I wouldn't hold in the same situation. But I don't enjoy anyone's pain or misery. That pain and misery won't be as bad as what others had to suffer due to the cruelty of some of your leaders - like shell-shocked orphans wandering aimlessly in the streets or mothers wailing inconsolably over the graves of their toddler children. But pain is still pain. And I'm worried. Just prepare for whatever is coming and hunker down. No one's future is guaranteed, including mine. So, good luck for now. I hope to continue this conversation on the other side.
Flagging is there for stuff that's off-topic or generating low-quality discussion in the views of the people clicking the flag link. Sometimes the admins will step in to unflag the article if it looks like neither of these apply, and/or if it would be helpful to have a containment topic for discussion of a particularly popular contentious topic.
Tautology isn't a useful reply to this question. At best it's a distraction, and at worst deflection. That people clicked the flagged link is already apparent by virtue of the post having been marked as flagged. That doesn't engage with why it was flagged.
0. the link was clicked by users of the site. The admins claim not to have any influence; I'm sure they do (if they want), but they seem to often enough rescue discussions from the flagged set that we can assume the readership exercises significant influence and there's no shadowy cabal generally trying to suppress wrongthink, as some seem to suppose. (Of course, perhaps there are a lot of people in the readership that are, and maybe they collude, but that is true for everything, and a far less interesting point)
1. if you want to know why the article was flagged, you will have to individually ask the people that flagged it. Sure, if you post the question here, it stands a non-zero chance of attracting the odd comment from these people, but it's quite obviously an inefficient way of finding out. What better ways are there? Well... none, really. But that means the answer is essentially unknowable, and the question barely worth asking.
So with the question barely worth asking - why ask it? It's just a sure-fire way to attract low-quality speculation, that will almost certainly blame it on: well, take your pick! - in some unproductive fashion, probably engendering some ongoing predictable discussion about the current bugbears of cranks of whatever stripe end up joining in.
(Or, suppose the question is posed by somebody unsure how the flag mechanism works: I think my reply actually does cover this case well enough.)