Do Not Put Your Site Behind Cloudflare if You Don't Need To

At the time of writing 12:43 UTC on Tue 18 Nov, Cloudflare has taken many sites down. I'm trying to browse the web, but about half of the sites show an error:

Most of these sites are not even that big. I expect maybe a few thousand visitors per month.

This demonstrates again a simple fact: if you put your site behind a centralized service, then this service is a single point of failure. Even large established companies make mistakes and can go down.

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Generating an SSH key for a webserver

Assuming you have the SSH password for a webserver called say case and email email@example.com, you can generate a key as follows:

ssh-keygen -t rsa -b 4096 -C "email@example.com" -f ~/.ssh/case

Next, add the server, which has say username user at location case.example.com, to your ~/.ssh/config:

Host case
    HostName case.example.com
    User user
    IdentityFile ~/.ssh/case

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Ondernemer op Reddit over subsidies

De enige vorm van “subsidie” die ik als ondernemer concreet ervaar, zijn de belastingen die ik betaal. Het lijkt – en ik zeg nadrukkelijk lijkt – alsof je reactie komt vanuit een positie waarin men niet hoeft te dragen wat ondernemers dagelijks moeten dragen. Zonder een gezond bedrijfsleven bestaat er geen economische ruimte voor sociale voorzieningen of luxe waar we als samenleving allemaal van profiteren.

Ik zeg niet dat vermogenden nóg rijker moeten worden, maar ik kan je verzekeren dat het tegenwoordig voor veel ondernemers, zelfs met een goedlopend bedrijf, buitengewoon moeilijk is om financieel overeind te blijven. Kosten stijgen, marges dalen en de risico’s liggen volledig bij de ondernemer. Dat perspectief verdient minstens net zoveel erkenning in deze discussie.

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Some Thoughts on High Frequency Currents and Oxidative Stress

As I wrote before, there is much research that shows that electromagnetic radiation causes oxidative stress. This means that electromagnetic radiation can knock an electron out of a molecule, which is called ionizing radiation. Some people say that electromagnetic radiation from radio frequencies is non-ionizing, but this contradicts the fact that many studies have shown that radio frequencies also produce oxidative stress. The higher the frequency, the more ionizing (read: damaging) the radiation is.

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Cell and DNA Damage and Repair from Different Kinds of Radiation

A very interesting fact from the book Light: The Medicine of the Future (1990) by Jacob Liberman is that far-ultraviolet radiation (UV-C), 100-280 nm, causes DNA damage and shortens cells' life spans, according to a study by Dr. Smith-Sonneborn.

However, she found that near-ultraviolet radiation (UV-A), 320-400 nm, repaired cells and reverses aging. Even more, it repairs DNA while damaged DNA is known to cause cancer. This suggests that sunlight can repair cells and reverse aging since sunlight that reaches the earth is mostly above 270 nm, according to Wikipedia:

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Solar Cell Spectral Sensitivity

I just came across the book Solar Secrets (2014) by Peter Lindemann. It observes that most solar panels are optimized to perform on bright sunny days whereas they barely perform on cloudy days. This while there are panels that capture light of lower wavelengths and are therefore much less affected by clouds.

The author shows this in the following figure from page 17:

Here it can be seen that Amorphous Silicon (a-Si) solar panels produce energy from the 500 to 700 nm wave length range while Crystalline Silicon (c-Si) mostly produce energy from the 700 to 1100 nm wave length range. a-Si panels even perform well behind glass since the visible light is between 380 to 750 nm.

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AI Crawler Mitigation via a Few Lines of Caddy

To mitigate AI crawlers, simply require a bit of Javascript:

domain.com {
    # Match all requests without a "verified" cookie"
    @unverified not header Cookie *verified*

    # Serve them a JS page that sets the cookie
    handle @unverified {
        header Content-Type text/html
        respond <
            document.cookie = 'verified=1; Path=/;';
            window.location.reload();
            
        EOF 418
    }

    # Handle all other requests normally
    reverse_proxy localhost:3001
}

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Timeless quote from Martin Luther on the Basilica of St. Peter

Christians are to be taught that the pope would and should wish to give of his own money, even though he had to sell the basilica of St. Peter,

From his 95 theses (1517).

On Pearl Powder

I've seen freshwater pearl powder being presented as healthy primarily due to it being a natural source of various minerals. Although the sales talk sounded convincing, it's probably good to verify the claims.

Pearl powder is part of traditional Chinese medicine and was mentioned in the Hai Yao Ben Cao. First of, freshwater pearl powder contains primarily calcium carbonate (CaCO₃) and magnesium carbonate, and some proteins, glycoproteins, and polysaccharides (Loh et al., 2021; Latire et al., 2017). Pearls according to a test with a spectrometer also contains 0.2% natrium, 0.04% manganese, 0.03% strontium, and even smaller amounts of barium, magnesium, and lead (Karampelas et al., 2019). These elements are normally present in drinking water or food and either not harmful or even an essential nutrient. Compared to the lead pipes that many old houses still have, these levels of lead should not be a problem (and some also claim that lead is not as unhealthy as the WHO is presenting).

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On the Health Effects of Electromagnetic Radiation

We've all seen or heard people who claim that electromagnetic radiation has negative health effects. I decided to look into the scientific literature to see whether the claims are true and if yes what health effects one could expect. The search is a preliminary one so it will not be particularly structured.

As a start, Wikipedia makes an interesting claim on the non-ionizing radiation page. The article writes that:

Non-ionizing (or non-ionising) radiation refers to any type of electromagnetic radiation that does not carry enough energy per quantum (photon energy) to ionize atoms or molecules—that is, to completely remove an electron from an atom or molecule.

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