In the May 2000 issue of Reason Magazine, award-winning science correspondent Ronald Bailey wrote an excellent article titled “Earth Day, Then and Now” to provide some historical perspective on the 30th anniversary of Earth Day. In that article, Bailey noted that around the time of the first Earth Day in the 1970, and in the years following, there was a “torrent of apocalyptic predictions” and many of those predictions were featured in his Reason article. Well, it’s now the 47th anniversary of Earth Day, and a good time to ask the question again that Bailey asked 17 years ago: How accurate were the predictions made around the time of the first Earth Day in 1970? The answer: “The prophets of doom were not simply wrong, but spectacularly wrong,” according to Bailey. Here are 18 examples of the spectacularly wrong predictions made around 1970 when the “green holy day” (aka Earth Day) started:

Scène de ballet, pour cordes, harpe et timbales, en mi majeur
Joseph Hellmesberger

In partnership with Hillsdale College, The Golden Thread Curriculum offers a rigorous, structured approach to the teaching of Western Civilization—one that restores coherence to history and equips students to understand the enduring questions, traditions, and tensions that run through the history of the West—from antiquity to the present.

THE NAZARENE
You know how he died.
Read how he lived.

Read free →
The whole first book is free. No account needed.

The life of Jesus as a novel, in four books, by EKO

Genes and archaeology are revealing how Bantu speakers spread across much of Africa. //

Scientists are extremely interested in the peoples who created this and other iron-powered societies across eastern and southern Africa. Research points to an adaptable and innovative group from western Africa as the masterminds. Known as Bantu speakers, these communities began gradually expanding across the continent’s southern half, starting from 6,000 to 4,000 years ago. In doing so, they introduced a fundamentally new, sedentary way of life—characterized by farming, raising livestock, pottery-making, and metalworking—to regions previously dominated by hunter-gatherer communities.

This migration transformed not only the region’s history and technology, but also its languages: Today, around 350 million Africans speak one of roughly 500 distinct Bantu tongues, from southern African Zulu to eastern African Swahili. And at least as many Africans—as well as many African Americans and Afro-Latinos—carry Bantu ancestry in their DNA. //

Linguists working in the 19th century started referring to the language family as Bantu, the plural of muntu, meaning “human being” in many Bantu tongues. Later linguists reasoned that the languages stemmed from an ancestral people who migrated across the continent from western Africa, which harbors the greatest diversity of Bantu languages (as would be expected for where the languages originated).

I was made aware of a small open source utility called scrutiny. It is very nice. Imperfect but a lot better than just running smart tests. It has small footprint and can help me see all disks from all systems in my home and lab in a single place.
I intend to add the how-to for anyone interested. I spent some hours over the week in getting to do what I wanted.
First, the project's home is here https://github.com/AnalogJ/scrutiny . Has 90% I'd say of the information needed. The remaining bits are the details for each type of system.
Second, this is a docker thingie that I'm not a fan of but the non-docker option is still a self-container utility in go language so it doesn't give me what I prefer like a front end and application I can configure independently. So I went with docker and using docker compose.

I used the mixed mode of hub & spoke. That is a "server" listening (the hub, using docker) and each system I want to monitor its disks are spokes, using the binary locally which sends the metrics to the hub.

ZNAS - Easiest and most beautiful NAS Management UI Ever

Why ZNAS?

Most NAS software is slow to install, slow to load, and buried under layers of configuration. ZNAS is the opposite.

• Up and running in minutes. Flash a USB stick and boot, or run one command on Debian or Ubuntu, then create your admin account in the browser.
• One binary, nothing else. No Docker, no Node, no Python runtime, no database. The whole portal, UI included, is a single file that starts in under a second.
• Storage, sharing and virtualization together. ZFS pools, SMB/NFS/iSCSI shares, VMs, containers and Compose stacks, all managed from the same place.
• Always current, never disruptive. Updates are signed, applied in one click and take effect in seconds, like a modern browser. The previous version stays as a fallback.
• Secure by design. HTTPS only, roles with fine-grained permissions, two-factor login, an audit trail of every action, and optional sudo hardening.
• Built for real homelabs. Manage several servers from one window, back VMs up to another box, watch your UPS, and get alerts wherever you want them.

1. Flash it to a USB stick, boot your NAS from it, and open the address shown on the screen. That's it.

2. Prefer a regular install? One command on Debian 13+ or Ubuntu 26.04+ sets up ZFS, a service account, the portal and its systemd service.

FreeCORE continues TrueNAS® CORE 13.3 as an independently maintained operating system for NAS appliances, with in-place upgrades to FreeCORE 15.0 and 15.1.

An independently maintained operating system for NAS appliances, on FreeBSD® 15 with OpenZFS.

My squadron ops officer had a peculiar view of this inspection, however. As one of the Seagull (have to throw rocks at them to make them fly) brothers I mentioned earlier in the book, he flew very little and absolutely would not fly in command with ASEV evaluators. His mantra said this was a reservist inspection and they should carry the load, not the technicians. //

A few weeks after that I dropped by Base Personnel to review the OER to see what kind, and level, of endorsements I had received. In reading the front of the form, however, I saw the statement citing my flying in command for ASEV had been removed.

A tough call
The next time I was in the squadron I stepped into the ops officer’s office and brought this to his attention. “I can’t find the sentence about me flying in command with ASEV,” I said.

He frowned and nodded his head to imply he had had to make a difficult decision and said: “I know, Jay, it was a tough call but I had to remove that sentence. It would have made all the other ARTS [especially him] look bad.”

Stunned, I couldn’t even speak, and didn’t.

I turned, walked down the hall to another office, and called Larry Mercker at Westover.

“Larry,” I said, “I’m ready to move, is that position still open?”

It was, and off I would go to Westover for the next five years as ADO.”

Romance pour alto et orchestre op.85
Max Bruch

L'œuvre
Romance pour alto et orchestre, en fa majeur (Op. 85)

Tempo di Mazurka
Alexander Müller

L'œuvre
Tempo di Mazurka, pour piano

System mails generated by your Plesk server, such as bounce notices from MAILER-DAEMON@hostname.example.com, cron output from root@hostname.example.com, or Plesk notifications, often land in the spam folder, even though normal user mailboxes (e.g. info@example.com) deliver fine.

This happens because your server’s hostname is a subdomain of your main domain, and your main domain’s DMARC policy is silently inherited by every subdomain that does not publish its own. Without dedicated authentication for the hostname, self-generated system mail fails DMARC alignment and is quarantined by your own authentication stack.

This article walks through the root cause, the one-DNS-record fix that solves the visible symptom for most admins, and the full authentication setup for getting non-bounce system mail to genuinely pass DMARC.

The quick fix: override subdomain inheritance

Add a dedicated DMARC record for your server hostname with p=none:

_dmarc.hostname.example.com.  IN  TXT  "v=DMARC1; p=none; rua=mailto:dmarc-reports@example.com"

This overrides apex inheritance for the hostname subdomain only. Your main domain DMARC policy stays strict, your user mailboxes stay protected, but system mail from the hostname stops being quarantined.

This single record solves the symptom for most admins. No Plesk changes are required. No server configuration is required. //

If you also want cron output and Plesk notifications (not just bounces) to genuinely pass DMARC, continue to the complete fix below. If you just want your system mail out of spam, you can stop here.

Open the panel.ini editor using the command:

 plesk conf panel.ini

Using the Plesk Panel Interface:

1. Install the Panel.ini Editor from the Extensions menu in Plesk.
2. Open Panel.ini Editor at Extensions > My Extensions.
3. In Panel.ini Editor, switch to the Editor tab. If the editor is empty, do the following...
4. Edit the content and click Save

Plesk administrator can specify a custom email address to be used as a mail relay. The email address will be used as the sender address for all Plesk email notifications enabled in the Tools & Settings > Notifications menu.

To adjust the settings, perform the following:

1. Log into Plesk
2. Edit the Plesk panel.ini file by adding the lines below there:

   [notification]
   senderAddress=<custom email address>

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 is /var/db/tailscale/ for state files and 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.

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