motd - 10/##/2026
-----------------

10/25/2026    App to remove AI from MacOS:

              https://github.com/omlahore/RemoveMacAI

              @12:58

10/25/2026    Manual fix for compromised eMudhra intermediate CAs on MacOS:

              https://support.apple.com/en-us/149555

              To remove root CA certificates from /etc/ssl/cert.pem:

              1. Back up the file. If a backup already exists, this command
                 keeps it:

                 [ -e /etc/ssl/cert.pem.orig ] || sudo cp -p /etc/ssl/cert.pem /etc/ssl/cert.pem.orig

              2. Remove emSign ECC Root CA - G3. This command makes a copy of
                 the file without emSign ECC Root CA - G3, checks that the copy
                 isn't empty, and replaces the original. It shows nothing when
                 it succeeds:

                 t=$(mktemp) && awk -v s='=== /C=IN/OU=emSign PKI/O=eMudhra Technologies Limited/CN=emSign ECC Root CA - G3' '/^(===|###) /{skip=0} $0==s{skip=1} !skip' /etc/ssl/cert.pem > "$t" && [ -s "$t" ] && sudo install -m 0644 -o root -g wheel "$t" /etc/ssl/cert.pem; rm -f "$t"

              3. [] Remov[e] emSign ECC Root CA - G3 doesn't block the six
                 certificates that Sectigo cross-signed, because these tools
                 can still verify them through AAA Certificate Services. To
                 stop these tools from accepting those six certificates through
                 the file until you install Apple's software update, you can
                 also remove AAA Certificate Services. This command works the
                 same way as the one in step 2:

                 t=$(mktemp) && awk -v s='=== /C=GB/ST=Greater Manchester/L=Salford/O=Comodo CA Limited/CN=AAA Certificate Services' '/^(===|###) /{skip=0} $0==s{skip=1} !skip' /etc/ssl/cert.pem > "$t" && [ -s "$t" ] && sudo install -m 0644 -o root -g wheel "$t" /etc/ssl/cert.pem; rm -f "$t"

              4. Check the result. This command lists either root CA
                 certificate if it's still in the file. If you removed both, it
                 shows nothing. If the command shows an error, restore the
                 backup from step 1.

                 openssl crl2pkcs7 -nocrl -certfile /etc/ssl/cert.pem | openssl pkcs7 -print_certs -noout | grep -E 'emSign ECC Root CA - G3|AAA Certificate Services'.

              @12:52

10/21/2026    White dwarfs may come in a variety of colors:

              https://www.thebrighterside.news/post/a-white-dwarfs-unusual-atmosphere-gives-it-a-ghostly-green-glow/
              https://arxiv.org/abs/2610.18966

              "If metals such as carbon, calcium, or sodium are present in
              the[] ultra-dense atmospheres [of a white dwarf], extreme
              broadening of atomic and molecular opacities can produce optical
              spectra that diverge significantly from blackbodies. We
              investigated how the combination of temperature and chemical
              composition can affect the perceived colours (chromaticity) of
              white dwarfs. While we found that most white dwarfs are similar
              in colour to blackbodies, we also demonstrate examples of known
              stars that would appear yellow, green, cyan, pink, or purple if
              viewed close enough for their stellar discs to be resolved."

              @21:17

10/21/2026    Classical Music Explained:

              https://www.youtube.com/@ClassicsExplained/videos

              @21:11

10/21/2026    My Computer for Nautilus:

              https://github.com/yannmasoch/nautilus-my-computer

              @21:08

10/15/2026    Fermium-255 has non-spherical nucleus:

              https://www.thebrighterside.news/post/lasers-reveal-a-rugby-ball-shaped-nucleus-inside-fermium-255/

              "High-resolution laser measurements show that the heavy nucleus
              is strongly elongated and carries magnetic properties that differ
              sharply from older estimates.

              The isotope contains 100 protons and 155 neutrons. Researchers
              determined that its nucleus has a stable prolate shape, meaning
              it resembles a rugby ball rather than a sphere."

              @22:50

10/15/2026    Experimental cold resistant alloys:

              https://www.nature.com/articles/s41586-026-11065-7

              "Our findings demonstrate that NbTi-based alloys can retain
              exceptional damage tolerance, with no measurable [ductile to
              brittle transition temperature] observed down to 20K. These
              properties are derived from a global mechanistic sequence that is
              unusual for bcc alloys in tension[.] ... Whereas most metallic
              alloys (particularly those with the [face centered cubic]
              structure) generate high toughness from a global sequence that
              begins with dislocation glide and progresses to twinning and a
              phase transformation that delocalizes dislocation-induced
              damage[], the global sequence in the current alloys begins with
              twinning (mediated by screw dislocation core transformation)
              coupled to a phase transformation that nucleates dislocations to
              dissipate stress concentrations produced by the former two
              mechanisms."

              @22:27

Older
-----

01/##/2026    https://srirangav.github.io/motd/2026/01/motd.txt
              https://srirangav.github.io/motd/2026/01/index.html

##/##/2025    https://srirangav.github.io/motd/2025/motd.txt
              https://srirangav.github.io/motd/2025/index.html

##/##/2024    https://srirangav.github.io/motd/2024/motd.txt
              https://srirangav.github.io/motd/2024/index.html

##/##/2023    https://srirangav.github.io/motd/2023/motd.txt
              https://srirangav.github.io/motd/2023/index.html

##/##/2022    https://srirangav.github.io/motd/2022/motd.txt
              https://srirangav.github.io/motd/2022/index.html

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