James Madison is the Father of our Constitution, and the Robert H. Smith Center for the Constitution at Madison’s Montpelier provides educational programming for teachers, law enforcement officers, and others.
That seems appropriate. After all, not only did Madison—our country’s fourth president—help draft the Constitution, but he also served as a key delegate at the Constitutional Convention, authored the Bill of Rights, and urged ratification of the Constitution through his practical and philosophical arguments in The Federalist Papers.
But these accomplishments are, at best, downplayed at his historic home. Montpelier has no exhibits dedicated to Madison and his contributions.
Worse still, Montpelier is equipping educators to teach Marxist-based theories to elementary, middle, and high school students. And the programs doing this are, in part, funded by the state of Virginia. //
It’s sad that Montpelier has chosen to focus on a Marxist-motivated movement fueled by critical race theory, instead of on the many astounding achievements of the home’s former owner and the Father of our Constitution, James Madison.
It’s a disservice to the public, teachers, and students.
Scientists find a "mitotic stopwatch" that lets individual cells remember something. //
How does something as fundamental as a cell hold on to information across multiple divisions?
There's no one answer, and the details are really difficult to work out in many cases. But scientists have now worked out one memory system in detail. Cells are able to remember when their parent had a difficult time dividing—a problem that's often associated with DNA damage and cancer. And, if the problems are substantial enough, the two cells that result from a division will stop dividing themselves.
Supersonic flight without loud booms? NASA is working on that. //
When earlier designs flew faster than sound, individual shockwaves coming from different features like the nose, canopy, and wings merged into one powerful shockwave as they traveled to the ground. “We designed the X-59 so that those individual shockwaves don’t merge, which makes the boom quieter,” said Mike Buonanno, the X-59 air vehicle lead at Lockheed. //
“This way the vast majority of shocks generated by the X-59 are directed upward, and very few go to the ground,” Richardson explained. But perhaps the most unusual victim of eliminating shock-generating features was the canopy. The X-59 has no front-facing windows. //
And it is quiet—the sonic boom it will make should be around 75 PLdB, roughly like a car door slam from 20 feet away. //
On a New York to Paris flight, Concorde burned through roughly four times more fuel than the Boeing 747 while carrying one-fifth of the passengers.
The problem is that you can’t really do much about both fineness and lift-to-drag ratios—they're limitations imposed by pure physics. If you wanted to keep the right fineness ratio and have enough space for over 500 passengers in a supersonic airliner, you’d just need to make it absurdly long. //
Concorde used 119,600 L of fuel to carry 120 people 7200 km. That's 13.8 L/100km per passenger – almost exactly double the consumption of the Boeing 707, at best; it was worse on shorter flights. The subsonic planes that fly its routes now get 2.2 to 3.4 L/100km per passenger.
That, more than anything, is what killed it. Even if you sold every seat in a Concorde, it had six times the fuel bill per ticket of a similarly sized subsonic plane. It would have become uneconomical even if maintenance were negligible and spare parts were free, which they were not.
Can modern engine technology bring that down? Maybe. I can see 7 L/100km per passenger being potentially achievable with lots of R&D. //
RZetopan Ars Scholae Palatinae
8y
1,222
"At Mach 2.2, air friction heated up Concorde’s fuselage to 121° Celsius"
We see this error a lot, even when describing asteroids entering the atmosphere. The temperature rise is due to the rapid compression of air and not due to an alleged friction. A boundary layer forms near any surfaces parallel to the air flow (just like liquids flowing in a pipe) while the heat is generated at the leading and trailing edges where the surface is not parallel to the flow and the air must undergo a rapid change in speed. Any locations where the flow is forced to quickly change speed is where maximum heat is generated due to the rapid compression. These are the same locations where shock waves form in supersonic flows. Given the large number of errors in this article, we can assume that the author is neither familiar with fluid flows nor supersonic aircraft. Relying on mass market newspaper reports often leads to promoting totally nonsensical claims*.
*Having been subjected to newspaper reporters on multiple occasions, it is astonishing how wrong they can be, both before and after "informing" them. For a trivial example, look at what happened to Irving Finkel's report on a 4,000-year-old cuneiform translation: //
Wickwick Ars Legatus Legionis
14y
33,543
paulfdietz said:
I see your claim fairly often, and I find it very annoying. It seems to equate the heating in supersonic flow with the heating air undergoes in adiabatic compression, for example in a bicycle pump.
But heating at a shock is not an adiabatic (entropy conserving) process. Shocks are irreversible. Entropy increases across a shock as fast molecules slam into slow ones in a region a few mean free paths wide. Compression does occur at a shock, but the heating is higher than is required by the increase in density. Indeed, there is a finite upper limit to the density ratio of a gas going through a shock, regardless of Mach number.
At sufficiently high speed, and particularly for the atmospheric entry case you describe there, almost all the heating is due to dissipation. In that respect it's much more similar to friction (a dissipative process) than it is to adiabatic compression.
You're conflating isentropic (reversible) and adiabatic. Adiabatic is the correct term in this case. In the limit of mild shocks (or low-angle oblique shocks), a shock wave of pressure ratio -> approaches an isentropic process.
Almost all shocks are adiabatic. That just means there's no heat transfer during the process. Which is the case. My compressible flow book has a single chapter discussing non-adiabatic shocks at the end of the book. These are when water condenses out of air, e.g. There's no external heat transfer, but the gas phase loses energy to the liquid phase so it's a non-adiabatic process for the gas.
But that dissipation isn't friction. It's compression heating when the compression is done too fast.
Edit: Let's put some numbers on this. Let's consider a Mach 2.2 normal shock (at the tip of the nose) at 15 km. That's 12 kPa and, -56.5C (216.7K), and 195 mg/m^3 density.
My compressible flow tables put the pressure ratio at 5.48 and the temperature ratio at 1.8569 (for gamma = 1.4 or air). That means the density change is 2.95 (Pressure ratio over temp ratio). So we've got a final density of 575 mg/m^3 at 402.3K (129 C). Isentropic compression to achieve a density ratio of 2.95 would be a pressure ratio of 4.54 (again, gamma = 1.4). And the temperature ratio for an isentropic compression of pressure ratio 4.54 is 1.54. So the isentropic temperature rise (so no dissipation) would result in a temperature of 334K or 61 C. So the isentropic compression heating would be 117 deg. C while the adiabatic heating would be 185.6 deg. C. So, in fact, pure reversible heating would do more than half of the heating that is experienced through a normal shock wave at Mach 2.2.
Purdue University mathematics professor Clarence Waldo was only at the Indiana Statehouse to lobby for the school during budget talks in February of 1897. That’s when he happened to witness House Bill 246 – to legally change the value of the number pi to 3.2 – pass its third and final reading in the General Assembly’s lower house. //
Waldo resolved to make sure the Senate didn’t make the same embarrassing mistake, privately coaching several senators on how to speak against the bill. At the same time, newspapers outside the state were picking up the story, correctly making fun of Indiana legislators for being so easily hoodwinked.
Sen. Orrin Hubbel of Elkhart County took the lead in trying to kill the bill when it reached the floor of the Senate, calling it “utter folly” and stating he and his colleagues “might as well try to legislate water to run up hill as to establish mathematical truth by law,” according to a report in the Indianapolis Journal.
Thankfully, the bill died before coming to a vote, but that was due more to Waldo’s lobbying and the negative publicity than any principled opposition based on basic mathematical knowledge.
Malicious code planted in xz Utils has been circulating for more than a month. //
GolbatsEverywhere
This might have been the worst Linux backdoor in history except that it was caught so soon. An SSH authentication backdoor is surely worse than the Debian weak keys incident and also worse than Heartbleed, the two most notorious Linux security incidents that I can think of. Probably this would have been abused to hack most if not all of the Fortune 500, except Mr. Freund decided to investigate some small performance issue that anybody else would have dismissed as unimportant. We are spared only due to sheer dumb luck. This guy has probably just averted at least billions of dollars worth of damages. Cannot emphasize enough how grateful we should be to him right now. //
dwrd Ars Tribunus Militum
6y
2,020
Subscriptor++
Big oof, after reading the commit messages, I'm going to have to assume they owed some bad people a lot of money, or they had an involuntary sleepover at an undisclosed location with several ill-tempered fellows from the state secret police agency. //
This could have made it into a lot more places had they not been doing benchmarking at just the right time.
Milliseconds. About 500 milliseconds. That's what started him down the rabbit hole. He was bothered by a half-second hiccup in an ssh connection refusal. //
crepuscularbrolly Ars Scholae Palatinae
17y
802
Subscriptor++
Andres Freund's post on OpenWall indicates the backdoor is only injected if:
targeting only x86-64 linux
Building with gcc and the gnu linker
Running as part of a debian or RPM package build
But, better safe than sorry.
Third-party-Tools to check your configuration
The SBC6120 Model 2 is a conventional single board computer with the typical complement of EPROM, RAM, a RS232 serial port, an IDE disk interface, and an optional non-volatile RAM disk memory card. What makes it unique is that the CPU is the Harris HD-6120 PDP-8 on a chip. The 6120 is the second generation of single chip PDP-8 compatible microprocessors and was used in Digital's DECmate-I, II, III and III+ "personal" computers.
The SBC6120 can run all standard DEC paper tape software, such as FOCAL-69, with no changes. Simply use the ROM firmware on the SBC6120 to download FOCAL69.BIN from a PC connected to the console port (or use a real ASR-33 and read the real FOCAL-69 paper tape, if you’re so inclined!), start at 2008, and you’re running.
OS/278, OS/78 and, yes - OS/8 V3D or V3S - can all be booted on the SBC6120 using either RAM disk or IDE disk as mass storage devices. Since the console interface in the SBC6120 is KL8E compatible and does not use a HD-6121, there is no particular need to use OS/278 and real OS/8 V3D runs perfectly well.
The SBC6120 measures just 4.2 inches by 6.2 inches, or roughly the same size and shape as a standard 3½" disk drive. A four layer PC board with internal power planes was needed to fit all the parts in this space. A complete SBC6120 requires just 175mA at 5V to operate, and this requirement can easily be cut in half by omitting the LED POST code display. Imagine - you can have an entire PDP-8, running OS/8 from a RAM disk, that’s the size of a paperback book and runs on less than half a watt!
Celebrating the world's first minicomputer, and
the machine that taught me assembly language.
The 12-bit PDP-8 contained a single 12-bit accumulator (AC),
a 1-bit "Link" (L), and a 12-bit program counter (PC):
Original photo credit: Gerhard Kreuzer
Later models (the /e, /f, /m & /a) added a 12-bit multiplier quotient (MQ) register.
The term “minicomputer” was not coined to mean miniature, it
was originally meant to mean minimal, which is a term that,
more than anything else, accurately describes the PDP-8.
Whereas today's machines group their binary digits (bits) into sets of four in a system called “hexadecimal”, the PDP-8, like most computers of its era, used “octal” notation, grouping its bits into sets of three. This meant that the PDP-8's 12-bit words were written as four octal digits ranging from 0 through 7.
The first 3 bits of the machine's 12-bit word (its first octal digit) is the operation code (OpCode). This equipped the machine with just eight basic instructions:
CHECK DNS PROPAGATION
Whether you have recently changed your DNS records, switched web host, or started a new website - checking whether the DNS records are propagated globally is essential.
Check DNS, Urls + Redirects, Certificates and Content of your Website
Use this server to make DNS queries against an Unbound instance and get logs. The Unbound instance is configured very similarly to Let's Encrypt's production servers, and is started fresh for each query so there are no caching effects.
They're free, they're easy, they're open source, and they generate funny names. //
One is LocalSend, a cross-platform app with an open source client and protocol that I install wherever I can. The other lower-friction tool that's especially handy for guests and rarely used devices is SnapDrop, a website or web app you open on both devices and then send files through, entirely on your local network. It, too, has its code out there for anybody to view.
Neither of these apps is new, which is good. They've been around long enough to garner good reviews and trust from their users. Beyond sharing files between two humans, I've also leaned on them when setting up headless systems or other quirky devices. //
roo82
roo82 Ars Tribunus Militum
23y
2,137
Subscriptor++
I've been using PairDrop https://pairdrop.net/ instead of SnapDrop. It's a fork of SnapDrop with more features, and can also be self-hosted. That being said, I didn't know about LocalSend before this article, and might just switch to it instead.
The call, as I guess Mom suspected, was because her father died.
One of his possessions we inherited was a beautiful silver .38 revolver. Firearms of many kinds were all over rural Ohio in those days. Autumn was a dangerous time to be a deer or pheasant there or a little kid playing frontiersman in the bushes.
Dad’s childhood came on a dairy farm in rural western Canada in the years before electricity. “You need to know about guns,” Dad had said. So, we took a thick board out back and leaned it against a tree.
Dad pulled out this shiny pistol. “Here,” he said. “It’s not loaded.”
I reached for the gun. With no warning, the thing went off with a huge bang and blasted a large hole in the board. I may have yelled an unpleasant word. Dad was just standing there, all calm and fatherly.
“You said the gun wasn’t loaded!” I screamed.
“Everyone says the gun’s not loaded,” Dad replied.
That’s another thing my father said.
Dad was a quiet, friendly sort, almost shy in public. Sometimes, I’d be next to him when he’d mutter some observation that just broke me up. He was funnier than Jack Benny. //
Dad had occasional advice. “When you have something to do, do it now. Then, you’ll have time for fun stuff later.” I probably should have thought about that the past few days when I could have been writing this.
I realized later his parenting style was very Socratic. One Sunday, no matter how many times I yanked the cord, the stupid lawnmower defied my efforts to start it. Dad happened to walk by, “I’m sure you checked the gas tank.”
I hadn’t, of course. It was bone dry. So, he passed on that lesson in privacy without confronting me with my own stupidity.
Dad had a phrase, “Minus to a plus.” It was okay to make a mistake, as long as you learned something, anything, from it every time so you’d never make the same error again.
“Think of how far ahead of everyone else you’ll be when you grow up and avoid all these early mistakes.”
But it’s not brain surgery. Every woman’s cycle is different to some degree, which is why it’s up to each of us to attune to the signals of our bodies. When women experience fertility-related symptoms, we do research and hypothesize what might be the issue. We change certain variables from cycle to cycle, observe the changes, and test the most effective ones repeatedly. Then we draw conclusions based on all the best evidence and testing. It’s science by definition. When it comes to my menstrual cycle, yes, I’m becoming the best expert.
The feminist left hates it. They’re all “pro-choice” until women choose to tell about their adverse experiences with birth control and detoxify their bodies of hormone disruptors. Invoking The Handmaid’s Tale is always in vogue, but Democrats’ ugly little secret is that birth control isn’t just the best way to control reproduction; it’s the best way to control women. The longer women remain single and childless, the longer they tend to be dependents of the state and therefore Democrat voters. The fewer times they go on maternity leave, the more soulless hours they can clock for their corporate bosses.
But look around. Are efforts to make women more like men making us happier? The “explosion” of females flushing their birth control offers a resounding no. Women bought the feminist lie for a while, but it only bankrupted them. It turns out that having your health concerns dismissed is not “empowering.” Masking symptoms isn’t “liberating.”
Despite the media’s hand-wringing about “effectiveness,” women — and men —have way better birth control options available, such as cycle syncing and natural family planning. So you’ve been told you have to ingest synthetic hormones every day… but did you know you’re only fertile about one week out of every month? Now, knowledge like that is empowering.
Clive Robinson • March 28, 2024 6:04 AM
@ OldGuy, ALL,
Re : Chain of history
How we get from your,
“Then boss forgot his password, didn’t want to pay to get it unlocked, and turned me loose on it. Turned out their security consisted of XOR’ing every byte written to disk with the same hardcoded 8-bit value.”To,
https://www.cnet.com/news/privacy/judge-orders-halt-to-defcon-speech-on-subway-card-hacking/
And how history is being rewritten by AI agents etc.
Your comment brings back a memory from nearly a quarter of a century ago. With ElcomSoft’s Dmitry Sklyarov being arrested and as it later turned out illegally detained and coerced by the FBI on behalf of Adobe Systems and their P155 P00r security in their e-book reader that used what sounds like exactly the same encryption system,
“Dmitry Sklyarov the 27 year old Russian programmer at the center of this case was released from U. S. custody and allowed to return to his home in Russia on December 13 2001”https://www.eff.org/cases/us-v-elcomsoft-sklyarov
Interestingly, searching around shows that slowly bit by bit write ups on,
1, What Dmitry had presented at Defcon-9 about the truly bad state of e-book software.
2, The fact he was arrested on behest of Adobe for embarrassing them publicly about the very poor security in their e-book system
3, The fact it was even Adobe Systems or their product
4, The unlawful behaviour of US authorities
5, The names of FBI and DoJ people involved
6, The fact Dmitry was a PhD researcher.
7, A jury found both Dmitry and Elcomsoft entirely innocent on all charges brought against them.
Is getting “deleted from history” or made difficult to find, via the likes of DuckDuckGo and Microsoft AI based Search engines…
The case was quite famous at the time as it showed the FBI was not just “over reaching” but actively trying to crush legitimate academic research. With even the usually non political and non feather ruffling “Nature” making comment,
https://www.nature.com/articles/35086729
And how speaking “truth unto power” can have consequences,
‘https://www.linux.com/news/sklyarovs-defcon-presentation-online-supporters-reputation-bonfire/
Much of which is what got repeated by the Massachusetts Government against the three students and the RfID “Charlie Card”.
Clive Robinson • March 28, 2024 6:41 AM
@ OldGuy, ALL,
I forgot to add the all important,
https://en.citizendium.org/wiki/Snake_oil_(cryptography)
Which tells you,
‘One company advertised “the only software in the universe that makes your information virtually 100% burglarproof!”; their actual encryption, according to Sklyarov, was “XOR-ing each byte with every byte of the string “encrypted”, which is the same as XOR with constant byte”. Another used Rot 13 encryption, another used the same fixed key for all documents, and another stored everything needed to calculate the key in the document header.
‘You can see why your comment triggered my memory ancient memory 😉
This isn’t just any old dead white guy who is bleeding out at the center of this piece, however. This is Cato the Younger or, as his contemporaries knew him, Marcus Porcius Cato Uticensis, a Stoic, scion of the late Roman Republic, a famously incorruptible statesman, and an advocate for liberty (or at least what passed for it in those days.) He set a standard for statesmanship that is no longer seen; I can think of no one practicing politics today who is fit to stand in Cato’s shadow. //
houdini1984
7 hours ago
We need a Cato. We need a Cicero as well, an orator and philosopher who can lend eloquent words to the cause of saving our republic, but Cicero’s is a story for another day. From where will come our incorruptible Stoic? From where will come the statesman who will confront those who will drag our republic to ruin and tell them, “No, no further; this ends now”?
I’m concerned by the apparent fact that men like him no longer exist.
Sigh. No one is coming to save you. Hell, Cato couldn't even save Rome. By the time he was at his peak, the rot had already grown too deep and the people had largely given up on the idea of liberty. Eventually, that happens to all "free" societies. And why? Well, part of it has to do with the very idea that we need a Cato to save us.
That's one of the main weaknesses of the American experiment in self-rule. Too many people are looking for a superman to save them, rather than rallying behind the mortal men who are already in the field. DeSantis is a great advocate for liberty and sound government. So is Rand Paul. Ted Cruz. My own governor here in Iowa, whose response to Covid involved little more than confirming that she trusted us to make the best decisions about our health.
Unfortunately, that superman myth has overtaken our national psyche -- at least on the Republican side of the political aisle. That's the whole appeal of Trump. It's not that anyone believes that he understands the constitution, the idea of God-given rights, or the true burden that government places on liberty and individualism. Instead, it's that he's made himself larger than life, through decades of forcing himself into the spotlight and building a reputation as a winner. It's myth, but myth is an easy sell to the average person.
Forget Cato. We need tens of millions of normal Americans to commit to saying no to the ongoing Marxist revolution. We need a counter-revolution that restores our national identity. We need to get aggressive in our opposition to the would-be authoritarians and their statist agenda. Because that is the only thing that can possibly reverse our slide toward tyranny.
Now satellite overheads have been revealed by Business Insider which appear to show mock-ups in the Inner Mongolian desert of some of the important government districts in Taipei - Taiwan's capital city - along with what appear to be models of specific government buildings. It's hard to imagine any reason for this other than military training with an eye toward an eventual assault on these districts.
How could America shift so babies were more welcomed, less dreaded?
Tim Carney, author of the new book “Family Unfriendly: How Our Culture Made Raising Kids Much Harder Than It Needs to Be,” has a few ideas. He’d like to see corporations offer parents their child’s birthday off every year. He wants parents to not work so hard at parenting—and to never, ever, sign up their kids for a travel sports team. He’d like to see local governments prioritize sidewalks and denser housing, which would make neighborhoods safer for kids.
But he also wants us to think about why we have a falling birth rate—and what it says about us. After World War II, America had a baby boom, while Germany experienced a baby bust. Now, we’re struggling with our own baby bust, even as we are hammered by relentless discussions of America’s failures, the threat of climate change, and more. “The spirit of the age now is what I call civilizational sadness,” says Carney. “And the sadness is a belief that we’re just not good or that humans were a mistake.” //
"Kids make us be better people. They make us aspire to be better people, both our kids and other people's kids around us," says author Tim Carney.