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maxnoe

1,394 karma · joined February 28, 2017

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maxnoe··on Patrick Stewart has died
https://youtu.be/zMI702nCcPo?is=KHG_wzT32QzSC8xA
maxnoe··on eMudhra ignored Mozilla Root investigation deadline; blames social media
Many US institutions seem to have used eMudhra as a cert provider, including Cornell, and the U of Michigan, Maryland and Chicago.

Check InCommon Certificate Service.

maxnoe··on Nobel Prize in Physics 2026: Francis Halzen
> And probably most pertinent to this discussion, Pauli predicted Neutrinos before they were detected.

Because of the experimental result of missing energy in the beta radiation spectrum.

Bone of these were "pure thought experiments" as you describe. Many were side effects, new predictions of theories to address other experimental results, but none of them happened in isolation.

You simply don't make predictions about the real world in "pure thought experiments".

maxnoe··on Nobel Prize in Physics 2026: Francis Halzen
Particle physics processes in the sources we suspect accelerate particles in a way that results in a power law distribution of energies. So you can get extremely high energy particles, but the higher the energy the rarer.

And sources have a maximum energy they can accelerate particles to.

https://en.wikipedia.org/wiki/Fermi_acceleration

maxnoe··on Nobel Prize in Physics 2026: Francis Halzen
No they weren't.

All of it was driven by a flood of experimental results that were not compatible with classical physics.

See "Ultra Violet Catastrophe" in black body radiation, photo effect.

Planck famously performed curve fitting on the black body spectrum and only afterwards found the theoretical foundation for the function that fit the data.

https://en.wikipedia.org/wiki/Ultraviolet_catastrophe

maxnoe··on Nobel Prize in Physics 2026: Francis Halzen
We know this because

- In the beginning, for the first couple of events, only because they have way higher energies than anything in the solar system could produce - By now, with enough data collected, their origin correlates very well with the milky way - we are close to identifying several far away galaxies as well

This is the significance. Contrary to some statements published today, IceCube was not primarily built to study Neutrinos, it was built to study the universe using Neutrinos.

That's why we care where they are coming from, we want to learn about the astrophysical objects that produce them.

maxnoe··on On caring for user data: NeoVim caused Vim undo files to be deleted
> The application must be able to restore or regenerate the data

That's a break of the contract then, right? The application was not able to regenerate or restore.

Cache is the wrong place for a persistent undo file.

maxnoe··on Cherenkov Radiation
Cherenkov radiation is UV to visible blue light, it travels at the speed of light in the medium, which is lower than the speed of light in vacuum.

Only the charged particle that induces the emission travels faster than the local speed of light.

maxnoe··on Cherenkov Radiation
Astronauts have reported having difficulty sleeping due to cosmic-ray-induced Cherenkov flashes in their eye bulbs.
maxnoe··on Cherenkov Radiation
Very shortly summarized, only if the particle is faster than the local speed of light, you get constructive interference between many atoms that were polarized by the moving particle.

For a slower than light particle, you also get emission, but it is completely random and thus does not give the well defined emission in a cone of Cherenkov radiation.

For a faster than light particle, the spherical suddenly line up to form a cone:

https://en.wikipedia.org/wiki/Cherenkov_radiation#/media/Fil...

maxnoe··on Cherenkov Radiation
Neutrinos are neutral particles, they do not carry an electromagnetic charge. They thus do not cause any Cherenkov light themselves.

What Neutrino detector measure is the Cherenkov light emitted by secondary particles that are created when a Neutrino interacts with the matter inside the detector.

E.g. a muon Neutrino reacts with a water molecule producing a muon, which is a charged particle and thus emits Cherenkov light.

maxnoe··on Cherenkov Radiation
The article has a section about what it can be used for, but only mentions the uses of the IAEA.

Of course I am biased because I work in the field, but the by far most wide reaching application of Cherenkov radiation is in the detection of high energy particles, particularly in astrophysics.

- Imaging Atmospheric Cherenkov telescopes detect the Cherenkov radiation emmited in the atmosphere when a high energy cosmic ray or gamma ray creates an air shower

- Water Cherenkov Detectors detect Cherenkov light when the secondary particles of these air showers reach water tanks on the ground

- Neutrino telescopes like kamiokande, Icecube and km3net detect Cherenkov radiation in water or ice produced by secondary particles produced by the rare interactions of Neutrinos in their detector volumes

Modern, high energy astrophysics is all about detecting different kinds of Cherenkov radiation and then reconstructing the original particle properties.

maxnoe··on CERN Transitioning to Debian After Being a Longtime RHEL Institution
For industrial computers and other embedded systems.

Computing AFAIK is very much still based on RHEL-based distros, Alma Linux specifically.

https://linux.web.cern.ch/

maxnoe··on Future euro banknote design proposals
Because he composed the anthem?
maxnoe··on New Framework Desktop Option with AMD Ryzen AI Max+ Pro 495 and 192GB Memory
Who blatantly ripped that off from Karl Marx...
maxnoe··on 'Complex numbers are not needed for quantum mechanics'
> The square root of -1 doesn't correspond to any quantity you could count or measure directly (you can't have negative one apple, for instance)

That must be the worst explanation of complex numbers I ever read. It's not even remotely connected.

maxnoe··on No leap second will be introduced at the end of December 2026
Unix time does not count elapsed seconds in real time since 1970-01-01T00:00:00, this is a common misconception.

Unix time assumes a fixed number of seconds per day. 86400. If a leap second is inserted, either end of June or end of December, the day is 86401 seconds long.

There are different implementations for how your Unix time will behave 24 hours before to 24 hours after the leap second. A timestamp might just repeat during the leap second or the system changes the length of a second in a time range around the leap second introduction to make up the difference. This is called smearing.

A simple example is the elapsed time between these two timestamps:

    2016-12-31 23:59:50
    2017-01-01 00:00:10
Unix time differs by 20 seconds (assuming the system/library doesn't use smearing). But actually elapsed time is 21 seconds, since

    2016-12-31 23:59:60
was the last added leap second. This timestamp cannot be represented by Unix time (again assuming no smearing, with smearing you could).
maxnoe··on No leap second will be introduced at the end of December 2026
No, the current rules are being relaxed because with the current ones, a negative leap second _might_ happen in the near future.

It did not happen yet. No negative leap second that should have been inserted was skipped.

See this chart here:

https://en.wikipedia.org/wiki/DUT1#/media/File:Leapsecond.ut...

You can see the the positive leap seconds as jumps upward once the graph reaches around -0.5 s.

We were never close to reaching +0.5 seconds with a positive trend and we are still relatively far away from that.

maxnoe··on Incident with Pull Requests, Issues, Git Operations and API Requests
GitHub Incident again/
maxnoe··on Can You Find the Comet?
Imaging Atmospheric Cherenkov Telescopes, we detect optical light emitted by high energy particle Cascades in the atmosphere to observe cosmic gamma radiation.

The particles need the atmosphere to interact, Cherenkov light is only emitted in an optical medium and because it's optical light we measure we are affected by satellites. Not as strongly as optical telescopes though, because the air showers last for only tens of nanoseconds.

maxnoe··on Zed 1.0
One would be support for ligatures
maxnoe··on Can You Find the Comet?
Our telescopes actually need the (or at least an) atmosphere to function.

There are some classes of observatories, which you cannot build in space but which are still affected by satellites to some degree.

maxnoe··on Flickr: The first and last great photo platform
> This is where I usually insert that 3,000 year old Gandalf meme.

Elrond?

maxnoe··on Tip: Web requests should not be measured in Hz [Hertz]
Copying my comment from the other recent thread:

The authority on the definition of SI units is very clear:

> The hertz shall only be used for periodic phenomena and the becquerel shall only be used for stochastic processes in activity referred to a radionuclide

Usually, no radionuclides are involved in web requests.

https://www.bipm.org/documents/d/guest/si-brochure-9-en-pdf

maxnoe··on Vera C. Rubin Observatory has Discovered 11,000 New Asteroids
Keep in mind that our current instruments are not really sensitive to most exoplanets that would be interesting for a sci-fi setting.

Current instruments are mostly good at finding large planets around small stars, we are basically blind to earth-like planets around sun-like stars.

See e.g. https://www.nobelprize.org/prizes/physics/2019/queloz/lectur...

maxnoe··on SI Units for Request Rate (2024)
Please don't.

The authority on the definition of SI units is very clear:

> The hertz shall only be used for periodic phenomena and the becquerel shall only be used for stochastic processes in activity referred to a radionuclide

Neither is usually the case for requests.

https://www.bipm.org/documents/d/guest/si-brochure-9-en-pdf

maxnoe··on SI Units for Request Rate (2024)
Yes, the year has pi * 1e7 seconds

1e5 / 3.14e7 ≈ 3e-3, milli, not micro

maxnoe··on Am I German or Autistic?
Or as Stephen Fry put it: "Nature, Nurture and Nietzsche", very fitting here.
maxnoe··on OnlyOffice kills Nextcloud partnership for forking its project without approval
There is a section in the GitHub Readme of Eurooffice with a justification of the fork:

https://github.com/Euro-Office#euro-office-liberates-the-onl...

maxnoe··on Microsoft's "fix" for Windows 11
"Most companies still do not publish Linux builds for creative software"

There, fixed it for you.

It's not like Linux is the blocker here.

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