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cjensen

6,062 karma · joined September 29, 2011

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cjensen··on Multiple Sclerosis Causality
It's weird to me that they say 35 of the 801 MS cases were negative then positive before getting MS. The control group had 107 of 1566 were negative, but they don't bother to tell us how many of them ended up positive.

I assume enlisting is a high-risk place to get EBV, and without info on the control I don't see how you can draw conclusions. But I'm basing this on the summary rather than the actual article: does the article have the info?

cjensen··on Multiple Sclerosis Causality
EBV causes more severe symptoms the older you are. So everyone here who remembers getting it and it being terrible? That's because you got it as an adult. If you get it as a kid, it can be asymptomatic.

I got it at 36 and had a fever that leveled me for 3 weeks. Between "wait 1 week before bothering your doctor" and multiple rounds of tests, they didn't even diagnose it as EBV until the 3rd week.

cjensen··on PCI-Sig Releases 256GBps PCIe 6.0 X16 Spec
PCIe Gen5 is now available in the latest Intel desktop processors. There are very few lanes, so it can really only run a single GPU, but that's covers a lot of the potential market.
cjensen··on Folly: An open-source C++ library developed and used at Facebook
Their Synchronized<> is a thing we also came up with to use in our code. It's so helpful it should be part of the Standard Library.
cjensen··on The Bay Area has become a large declining tech company
SF has always been a far worse place to live and work unless you are young and like nightlife and restaurants and lots of socializing outside of the office. Yes, SF has gotten worse because too many petty crimes have been de-criminalized which has lead to the rational decision of bad actors to commit many petty crimes.

Outside of SF, life goes on as it always has. The major crime issues are (a) catalytic converter theft which costs the victim thousands and (b) car window breaks to grab any visible bags because too many techs leave their laptops in a visible bag.

Housing prices have always been rising, traffic is always getting worse. It's annoying, but not new. Companies have always been leaving and new places are always touted as the new "Silicon XYZ." The Silicon Glen. The Silicon Prairie. Silicon Forest.

I'm old. All this has happened before. All this will happen again.

cjensen··on Log4j RCE Found
It's in the 1.18.1 release candidate 3 which is scheduled to be fully released tomorrow.
cjensen··on In 2019 40% of San Francisco traffic fatalities are from left turns
It's odd to me that such a significant source of fatalities is being addressed in a very unambitious way. Left turns are clearly difficult maneuvers in many parts of SF. Why not turn them into protected left turns?

This "just blame the drivers" attitude is really odd. Their response is to tell drivers that they need to take more care and then enforce the care with an obstacle course. Why not do something harder that would be more effective? Protected lefts. Separating walk signals from green lights. Tickets to penalize poor driving. Tickets to penalize anyone walking out of turn. Tickets for anything that makes the left turn more complicated so drivers can focus on the job.

cjensen··on Scientists find a way to ‘catapult’ rockets into space like ‘slingshots’
Yep, the "wrong" velocity is what you suggest: the horizontal velocity is missing. Keep in mind the horizontal velocity is the critical detail that distinguishes "orbits" from "crash landings."

There is no conversion to linear momentum. The projectile is rotating once per turn of the centrifuge. Nothing they do eliminates that angular momentum. That's why in the linked video the projectile is, on close examination, rotating wildly. It's also why the projectile's nose exits the apparatus at a very different location than the tail.

cjensen··on Scientists find a way to ‘catapult’ rockets into space like ‘slingshots’
The tumbling in this video is a good demonstration of the angular momentum problem. The projectile has a carp ton of angular momentum after release, and there's no system in place to fix that. Maybe you could cancel it using the atmo and aerodynamics except that would probably melt the fins.

And angular momentum is just one of the challenges that appear to be unsolvable. When you hit orbital height, your velocity is in the wrong direction. How do you add enough horizontal velocity? How do you construct a rocket engine that can survive the forces involved in initial launch? How do you prevent the bearings from melting? How do you construct a launch chamber which survives the explosive compression when the projectile penetrates the vacuum barrier into the atmo?

And all with a Theranos-level of founder knowledge.

cjensen··on Solar-driven water splitting at 13.8% solar-to-hydrogen efficiency
A think you may have missed the part where I wrote "connection to the grid."

My point is create an energy storage station, all you need is water and grid power. No pipelines needed. This hypothetical power storage site would generate hydrogen during the daytime from surplus grid solar, then burn the hydrogen at night delivering the power back to the grid.

To be clear, I'm not necessarily talking about a solution for homeowners. An energy storage facility could cheerfully be as large Diablo Canyon Power Station. It just depends on the efficiencies of everything from the water-splitting process, storage solution, grid losses, and grid capacity.

cjensen··on Solar-driven water splitting at 13.8% solar-to-hydrogen efficiency
$1 trillion of pipelines? Why?

This is about splitting water using electricity. You can create and use the fuel at the same site. Just need a water pipe and a connection to the grid. Splitting off hydrogen at a separate site is just wastefull.

cjensen··on HandBrake – An open source video transcoder
Yes, and under the hood Handbrake is using the FFmpeg libraries. Handbrake's value is providing simple presets that "just work" for converting video for various uses. Want to convert video for playback on an iPhone? Handbrake has you covered.
cjensen··on A hash function using only add, sub, ror, and xor
Ok but why not use a PRNG for a hash function using the value as the seed? It will scramble the bits nicely.
cjensen··on Wikivoyage has disappeared from DuckDuckGo
As a former moderator at both sites who frequently explained this policy to contributors, no I didn't ask the maintainers, who once sued a moderator over the schism, any questions.
cjensen··on Wikivoyage has disappeared from DuckDuckGo
Yes. The footer of every page on Wikitravel makes that clear.
cjensen··on Wikivoyage has disappeared from DuckDuckGo
For authority: I hold copyright which I've never assigned to a "few" pages.

Wikitravel is using my content under the CC-bySA license. The license they are using my content under does not permit them to forbid someone from copying the content.

cjensen··on Wikivoyage has disappeared from DuckDuckGo
Wikitravel does not have any copyrights to anything, so I would hope not. It's all contributor-created content licensed under CC-by-SA which is free to copy under certain terms.

More importantly, Wikitravel is basically a dead man walking, and Wikivoyage is a living project.

cjensen··on Jack Dorsey says ‘hyperinflation’ will happen soon in the U.S. and the world
"There will be inflation" is indeed a reasonable prediction. But that is definitely not the definition of hyperinflation[1].

[1] https://en.wikipedia.org/wiki/Hyperinflation

cjensen··on [dead]
Not the flagger but... this is pure conspiracy theory. Even in bubbles like 2008, there are some economists who see bad things coming. This has zero support among serious economists.

If the argument was "inflation is coming," you'd have support. But "hyperinflation" is a specific term with catastrophic implications that is just unsupported by serious people.

cjensen··on Software Freedom Conservancy files GPL lawsuit against Vizio
There is no "first sale" for a non-transferrable software license -- even when you get it as a part of a physical good. You are confusing licensing with copyright, which is a different thing entirely.

When the second sale occurs, the seller must still obey the terms of the software license, which means the seller must give the end-user a full license which includes the ability to demand the source.

If it were otherwise, the GPL would be meaningless. Instead of the many BusyBox lawsuits, the companies could have "sold" their boxes, "bought" them back, then had no GPL obligations.

Lastly, without the GPL you have no software license and have no right to run the software.

cjensen··on FreeBSD switches the default root shell from csh to sh
Christiansen is correct that it is a terrible programming language.

It's a great shell for user input.

cjensen··on Leaded fuel reduced IQ of children born before 1990
Post hoc ergo propter hoc
cjensen··on Software Freedom Conservancy files GPL lawsuit against Vizio
Yes absolutely. You would be redistributing the software with the TV. That said, I can't imagine anyone would actually file a lawsuit in a situation like this.

More worrying is whether Costco and Walmart could be sued under this theory. Vizio sells very few TVs directly.

cjensen··on By 2500 earth could be alien to humans
That's an incorrect understanding of rainforests, and has me scratching my head at the article.

It rains because of Hadley cells. Hadley cells don't disappear with global warming, so it will still rain a lot in the tropics. Why on Earth would it be "barren?" A few degrees of temperature doesn't matter to plants: as long as there is sunlight and tons of water, they should be fine.

Now if Hadley cells widen or shift northward, that could be a problem for the US. But no matter what happens, Hadley cells still have to rise near the equator.

cjensen··on Apple Maps' Acceleration (2020)
Neither Apple nor Google check to ensure that roads actually exist. Both have imported USGS maps that include non-public roads which are gated shut to the public.

Example: 37.475,-121.753

Both Google Maps and Apple Maps will cheerfully give you directions to this location which is less than 15 miles from their respective headquarters. You can't get there.

cjensen··on The Home Depot Teams Up with Walmart to Expand Same-Day and Next-Day Delivery
Walmart will literally do the same thing. I order cereal from them because it's cheaper, and they have free delivery. But they split the order into two shipments -- one from the store, one from the warehouse. Walmart is not yet good at this type of logistics.
cjensen··on Tesla’s headquarters will move to Austin
When CEOs move, they often move their headquarters closer to where they live. Somehow Tesla managed to survive all the problems of California until shortly after Musk moved to Texas. Folks talking about the advantages and disadvantages of California vs Texas may be overthinking this.
cjensen··on Anyone Seen Tether’s Billions?
One dollar of Evergrande's debt -- that is, a promise to pay one dollar -- is not worth anywhere near a dollar. So besides the sketchiness of having lots of Chinese company paper on their "asset" books, there's the whole question of how they are valuing said paper.

In other words, when they say they have $1 dollar of assets for every $1 of issuance, is the asset an Evergrande promise to pay $1? Or is it an amount of stuff they can liquidate easily to obtain $1?

It's the former, of course. And the "auditors" they used checked and said "yep, they have the right amount of promises to pay from distressed Chinese companies that, if those companies actually pay, it will be enough money."

cjensen··on FCC plans to rein in “gateway” carriers that bring foreign robocalls to US
Sure, I don't but... my spouse helps take care of her parents. They aren't fluent in English, so my spouse handles all the calls and callbacks. That means she gets calls from unknown callers frequently that she must answer.

It's a big issue for people who actually need to answer calls from novel callers.

cjensen··on First Human Case of Rabies in Illinois Since 1954
A rabid bat might not be showing any symptoms, so you have to assume all bats might have rabies. That's why health authorities tend to say "just looking at a bat, you can't tell if it has rabies."

That said, daytime flying, obvious sickness, and aggression/biting are all symptoms of likely rabies in bats.

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