Balada d floripondios du Concierto de Otoño
Arturo Márquez

L'œuvre
Concierto de Otoño. Concerto pour trompette et orchestre

Tailscale’s download page doesn’t list if it’s available for FreeBSD. But it does work on FreeBSD (tested on Release 14). Here’s how:

Install the package:

 pkg install tailscale

Edit /etc/rc.conf to add tailscaled_enable="YES"
or

service tailscaled enable

Run service tailscaled start. If you get an error, reboot.

After reboot, run tailscale login.

Copy the url, copy paste in a browser and approve the connection. ////

XigmaNAS:

Copy /usr/local/bin/tailscale, /usr/local/bin/tailscaled and /usr/local/etc/rc.d/tailscaled to local storage from working full version of FreeBSD.

Use script to copy symlinks into /usr/local/bin and /usr/local/etc/rc.d/ after bootup.

Configuration and State Storage

The default configuration file locations for Tailscale on FreeBSD are typically /var/lib/tailscale/ for state files and /etc/default/tailscaled for configuration settings. Additionally, logs can be found in /var/log/tailscale.

The Ham Radio Prep program makes it fast, easy and fun to get your license in just a few hours of study time. Pass your exam on your first try or your money back, guaranteed!

sjl Ars Praefectus
20y
3,805
Caillebotte said:
The Manhattan project built a plutonium device and tested it in New Mexico, because it was not clear that it was going to work.
Of particular note is that the uranium device - Little Boy - was not tested before it was dropped. At all. They were completely confident it would work. It was hugely inefficient - it had 64kg of uranium, but less than one kilogram underwent fission - but it was simple enough that they didn't need to test it to know it would work.

The reason plutonium needed testing is because reactor-produced plutonium will have Pu-240 as a trace contaminant. The longer the U-238 stays in the reactor before being removed to extract the plutonium, the higher the percentage of Pu-240; and Pu-240 is poison to attempts to build a nuclear weapon. It spontaneously fissions, and that causes a gun-type weapon (like Little Boy) to trigger before the critical mass is fully assembled. Hence the need for implosion, and that in turn requires testing to verify that the implosion mechanism works properly. (But the tradeoff is that the longer the U-238 stays in the reactor, the more plutonium there is to extract - a short stay gives you higher purity, but much less material to refine.)

If they'd been able to produce pure Pu-239, as the early samples were (said samples were produced in a cyclotron rather than a reactor), the gun-type weapon would have been fine. But that would have been a very slow, hideously expensive, and grossly inefficient way to produce plutonium. Reactor-produced plutonium can be made in much higher quantities; the tradeoff of impurities is manageable once you know how to make an implosion type weapon.

Of note is that weapons for nuclear submarines are made with much higher purity Pu-239 than regular nuclear weapons: Pu-240 is more radioactive, so the higher purity Pu-239 weapons are safer for the seamen who are in relatively close contact for the duration of the deployment. For aerial weapons (ballistic missiles, bombs, and similar), a lower purity is acceptable.

Boskone said:
Bit of an OT question, but how dangerous is a uranium cube to handle (assuming one doesn't drop it on an appendage or the like)?

Relatively safe from a radiation point of view. It's primarily an alpha emitter, very little beta, not much gamma, and because it has such a long half life, the daughter products aren't significant contributors to risk. As long as you don't ingest it, you'll be fine. If you do ingest it, you have to contend with the damage from alpha radiation (can be a serious cancer risk internally, no risk if external) as well as the chemical toxicity of the material. Decent gloves are generally considered adequate for handling.

Koeth and Hiebert uncovered a box of declassified documents about German uranium in the National Archives and found about 400 other uranium cubes from a separate reactor experiment by the Gottow group. They concluded that the combined inventory would have been more than enough to achieve criticality in the B8 reactor, suggesting that Germany’s secretive, isolationist approach hampered their nuclear program, because the two groups weren’t sharing information or resources.

This latest paper builds on that earlier work but reaches a different conclusion. Koeth, Hiebert, and their co-authors analyzed two of the surviving uranium cubes, along with combing through historical records, technical reports, correspondence, and similar archival sources to learn more about the uranium, heavy water, and graphite blocks used for the B8 reactor experiment.

Among their findings: The B8 reactor would have needed between 1,292 and 1,775 uranium cubes to achieve criticality, and twice the heavy water produced by the Norsk Hydro plant in Vemork, Norway—the only source at the time—over the course of the entire war. In short, “Our calculations suggest Heisenberg significantly underestimated the materials required,” the authors wrote.

The authors also cited prior work noting key differences in American and German graphite production. The former used petroleum coke. While some of this supply reached Germany, the British naval blockade in January 1940 deprived the Germans of that vital resource. The German nuclear physicists had to use metallurgical coke from the Ruhr, which had twice as many impurities as American coke. (The US scientists had similar issues until they located an unusually low-boron coke in Pennsylvania.) Thus, “no natural uranium, graphite-moderated pile could have gone critical” with the materials available to the German scientists at the time. //

libelle Ars Centurion
6y
229

Spacer_Dan said:
Heisenberg significantly underestimated the materials required on purpose.

That's what he claimed after the war. It's entirely unclear if that was true.

rochefort Ars Praefectus
20y
5,361
Subscriptor
Albino_Boo said:
Its nothing to do with whst Hesinberg wanted to do, it what they could do with the resources given. The V1 and V2 project consumed more resources than Manhattan did. The German economy couldn't resource both to the degree needed and one with degenerate Jewish science wasn't chosen by the people that murdered 6 million Jews. Odd that. Hesinberg was not entirely reliable about what said he did versus what everyone else remembers
https://www.aps.org/archives/publications/apsnews/200208/viewpoint-seitz.cfm
That essay is oddly sympathetic to Heisenberg. Among other things, it says

[Fermi]...had by nature or acquisition developed appropriate "street smarts" that enabled him to understand exactly what was at stake. Heisenberg possessed neither the experience nor the gifts of insight that Fermi did.

What Fermi had most of all was a Jewish wife. //

eyesoars Ars Praefectus
15y
5,254
ProfessorScience said:
When you can look up all of the relevant data for neutron capture cross sections, fission cross sections, fission product yields, and whatnot in a book, no. When you have to learn all that from scratch, a fission reactor is an essential research tool.

When the Germans measured the neutron capture cross-section of carbon, the carbon they had had small amounts of boron, a potent neutron absorber, in it. The U.S. physicist who measured it was a notorious stickler, and made a significant effort to get very pure carbon. The difference between the measured values was about a factor two, leading the Nazis to conclude that heavy water was the only reasonable way towards a reactor, thus their interest in heavy water.

As for why suspend the cubes... I would presume that the contraption could be lowered into the moderator (water) until the reaction went critical, and the reaction rate could presumably be adjusted by raising and lowering the "chandelier" to a suitable depth in the D2O.

Stirling is a private PDF editor that runs anywhere and automates everything.

A pharmaceutical manufacturer in Puerto Rico needed a dependable, lower-cost alternative to an unstable public grid. ComAp partner Martin Energy Group designed and delivered a turnkey microgrid that combines LNG-fuelled combined heat and power (CHP), battery energy storage systems (BESS), and diesel backup generation, all coordinated by ComAp controllers. The aim was to keep the site's critical processes running without interruption, whatever the state of the grid. Martin Energy Group owns and operates the system and supplies the facility with power under a power purchase agreement (PPA).

Low costs and offline security mean magnetic tape still has a job. //

The project will run from fiscal years 2026 through 2028 to fund manufacturing expansion and additional personnel, primarily to produce the latest-generation “FUJIFILM LTO Ultrium10” tape.

"The health of our entire legal system—both state and federal—depends on having a competent and independent state judiciary... How we choose our state judges, and how we decide whether to keep them in office or not, is of critical importance."
—the Honorable Sandra Day O'Connor
Retired Associate Justice, Supreme Court of the United States

Judges up for Retention

The next judicial retention election for state appellate judges will take place in November ....

Short bio for each judge with links to Opinions authored by each judge.

Quick Share is Android's equivalent of AirDrop, meaning it's a native service for transferring files between two compatible devices. Quick Share was developed by Samsung and was initially available exclusively on Samsung smartphones. Google also had a similar feature called Nearby Share, which allowed file sharing between two compatible devices.

At the beginning of 2024, Google collaborated with Samsung to merge Quick Share and Nearby Share into a single cross-Android solution, naming it Quick Share. //

The app is available in the Microsoft Store, but unfortunately, the Microsoft Store version only works with Samsung Galaxy devices. //

If you have a smartphone from another brand, you'll need to download Google's Quick Share app. https://www.android.com/intl/en_in/better-together/quick-share-app/ //

A Google
Nah, it's too complicated. I'd rather use third party open source file transfer apps such as LocalSend. It's very fast, reliable, doesn't have compatibility issues (available for the 5 major platforms : windows, macos, linux, android, ios), and lightweight. No need to setup, just plug and play. Although, you can set up the options if you need.

Roy
A nice idea in theory but like so many similar products, buggy in the real world. I lost the connection between my phone and my PC multiple times. 5 bars reception on my phone, sitting right next to my wifi router which is sitting next to my hardwired PC. So bandwidth availability is not the issue. I have used the FOSS tool KDE Connect with some success, and will try LocalSend next.

Running out of phone storage is bad enough, and paying for a cloud subscription to fix it is an expensive habit. Now, your Windows PC will soon offer a much simpler alternative. Google is building an automatic backup feature into Quick Share that copies your photos and videos on Android phones straight to a computer. There’s no subscription or storage plan attached. //

The ability to back up Android photos to a Windows PC automatically is included in Google Play Services version 26.43. The rollout is happening in a phased manner, so it could take some time to reach eligible devices. It is also recommended to update the Quick Share app to the latest version on a Windows PC.

Despite the fuel efficiency of twin-jets, the 747-8F is actually a superior e-commerce machine when it comes to raw volume and layout. //

The 777F wins out on fuel efficiency for delivering lightweight packages, but it still carries a smaller payload every single time. According to UPS, a full 747-8 holds roughly 30,000 packages, a count that shows how many separate shipments one flight can contain. After cubing out the upper hold, the 747-8F can still pack the lower hold with smaller and heavier cargo,

In a world where twinjets are the dominant force, Atlas Air is a rare oasis of four-engine aircraft, with the US-based cargo and charter specialist still flying both the Boeing 747-400 and the 747-8F. These double-decker widebodies are recognizable enough in their own right, but three of them have just got a bit more distinctive after the application of mustaches on their nose cones to raise charity awareness. //

The initiative in question is Movember, which sees men around the world grow mustaches in November in order to raise money and awareness for causes such as cancer and mental health. Atlas Air has now taken this a step further by adding mustache designs to three of its own aircraft, which will act as flying billboards for the cause. //

a 747-400F registered as N453PA and a 747-8F registered as N851GT. //

The Boeing 747 series has all but disappeared from passenger flights in the 2020s, but it remains more of a key player in the charter and cargo fields that Atlas Air specializes in. According to Planespotters.net, some 65 of its 86 aircraft (75.58%) are from the Boeing 747 family, and it has historically flown another 48 jets from this series. Its crop of 65 'jumbo jets' is split between 48 747-400s and 17 747-8s. //

Atlas Air's 48 Boeing 747-400s are 26.6 years old on average, and five of them are configured for passenger charter operations, while the rest carry freight. Meanwhile, all 17 of its Boeing 747-8s, which are 11.3 years old on average, are freighters. As it happens, Atlas Air has a special place in history when it comes to the Boeing 747: it received the final production example of the type back in January 2023.

We have gone through the seven sins and watched each one grow from a private weakness into a public system. But the cures are as old as the sins, and our ancestors knew them all.

A civilization is made of what it rewards and punishes. Reward the sins, and they become systems. Reward the cures, and they become a civilization.

Where your distribution has released a fixed kernel, install it. The table above lists the packages and advisories for Debian, Oracle Linux, SUSE and Amazon Linux.

If you build your own kernel, the fix is in Linux 5.10.272, 5.15.223, 6.1.190, 6.6.159, 6.12.113, 6.18.56, 7.2.10 and 7.3. The kernel's CVE team recommends updating to the latest stable kernel. It says the kernel community does not support cherry-picking individual fixes.

Brandon Thomas built PhotoCraft, a free Photoshop rival, in about 24 hours. I asked him, rival developers, and a lawyer whether AI clones are legal, reliable, or ethical. ////

Business As Usual, With Alterations

exampleadultsite.com
is only a demonstration site.

If you were using OpenDNS Parental Controls or Web Filtering for business, this demo and real adult sites would be blocked.

InternetBadGuys.com is only a demonstration site.

If you were using OpenDNS,
real phishing sites would be blocked.

OpenDNS makes your Internet work better

Safer: helps prevent identity theft & blocks phishing sites.

Faster: speeds up your existing Internet connection.

Smarter: corrects spelling mistakes on the fly.

Get started in 2 minutes

It's free and there's no software to install. Get started.

When you finish configuring Umbrella, we recommend that you check your Umbrella policies. You can evaluate a policy by pointing your browser to one of our test destinations.

examplemalwaredomain.com is only a demonstration site.

If you were using OpenDNS Enterprise,
real malware sites would be blocked.