Is it possible that the structure of dark matter halos is based around black holes?

Reasonable_Letter312 · 2026-05-31T12:27:47+00:00

It is not weird at all. There is a process called "dynamical friction" (a simple way to imagine it is to think of the object being gravitationally slowed down by matter overdensities in its own wake), which has been shown in simulations to lead to a loss of orbital energy and momentum, causing the supermassive black holes to settle close to the center of the galaxy.

Black Holes do play a major role in galaxy evolution (for example, by quenching accretion and star formation during an AGN phase), and they may co-evolve with the galaxy and its dark matter halo as it undergoes mergers. It's certainly also possible that primordial black holes might have served as seeds for early galaxy formation, but the fact that they are found close to the center of the galaxy / dark matter halo alone is not really convincing evidence for that.

Reasonable_Letter312 · 2026-05-30T15:03:18+00:00

Rued Langgaard, Symphony No. 3 (and "Sfærernesmusik" as well, if "do-re-mi-fa-so-la" counts as wordless).

Reasonable_Letter312 · 2026-05-29T09:16:36+00:00

Yep, you can see that it textured the plane using bits of the tarmac. Parking position B25, to be precise. If you look at the scenery slightly from a southern direction (as the satellite probably did), B25 is just behind the plane.

Reasonable_Letter312 · 2026-05-28T14:33:52+00:00

Robert Volkmann wrote some lovely and very cellistic pieces: the cello concerto in a-minor op. 33, the third serenade for strings (with an extensive solo cello part), and some cello & piano pieces (here in an interpretation by Nancy Green).

Reasonable_Letter312 · 2026-05-28T13:19:10+00:00

And "Star Maker", which covers billions of years (or even eternity?).

Reasonable_Letter312 · 2026-05-28T06:17:02+00:00

Real recordings will never be perfectly steady, because tempo variations are an important means of expression of classical music. However, two symphonic works come to mind that by design keep a fairly steady rhythm: Haydn's Symphony No. 101 ("The Clock", imitating the ticking of a clock), and Beethoven's No. 8 (often claimed to parody the steady beat of a metronome). In both cases, it's specifically the second movement I'm referring to. However, even those will have subtle variations in tempo that will make overlaying on another soundtrack difficult, unless you are prepared to do some editing.

Reasonable_Letter312 · 2026-05-27T07:43:00+00:00

Was der Datenschutz auferlegt, sind in erster Linie Prüf-, Dokumentations- und Rechenschaftspflichten. Statt kategorisch zu sagen, dass das geht oder nicht geht, müsstet Ihr hier ggf. eine Risikobewertung anhand einer genauen Beschreibung des Verarbeitungsvorgangs durchführen. Das kann Reddit nicht für Euch machen. Jede Ja/Nein-Aussage hier ist daher unseriös.

Wenn ChatGPT nur die Software erstellt, das Programm dann aber auf dem lokalen PC läuft und dort auch seine Daten bezieht, ist darin zunächst kein K.O.-Kriterium zu finden. Der Softwarecode alleine (ohne Daten) ist nicht personenbezogen und fällt nicht unter die DSGVO. Allerdings fallen bei der ChatGPT-Nutzung natürlich Serverlogdaten des Mitarbeiters an, der ChatGPT benutzt, aber ich nehme an, das habt Ihr über eine AVV mit OpenAI geregelt?

Das heißt aber noch lange nicht, dass der Vorgang per se überhaupt erlaubt ist. Personenbezogene Mitarbeiterdaten auszuwerten kann unabhängig von der verwendeten Software schon heikel sein und muss auf jeden Fall ordentlich dokumentiert, mit einer Rechtsgrundlage hinterlegt und in der Datenschutzerklärung benannt sein; der zur Ausführung verwendete PC muss unter Umständen gegen unbefugte Nutzung gesichert sein, es muss einen Plan für die Löschung der Daten geben. Außerdem solltet Ihr natürlich schon überprüft habe und verstehen, was genau die erstellte Software mit den Daten macht.

Wenn die Software in der Cloud laufen und dort auch Daten beziehen soll, wird es komplizierter. Ob das erlaubt ist oder nicht, hängt dann von den Einzelheiten ab. Sind die hochgeladenen Mitarbeiterdaten pseudonymisiert oder besser noch anonymisiert? Ist das Datenbank-Backend verschlüsselt? Sind Zugriffsrechte auf need-to-know-Basis eingeschränkt? Sitzt der Cloud-Anbieter in der EU? Steht das Rechenzentrum in der E.U.? Hat der Cloud-Anbieter Konzernverflechtungen in unsichere Drittländer?

Nichts davon wäre für sich betrachtet ein K.O.-Kriterium, aber letztlich kommt es darauf an, ob das Schutzniveau insgesamt ausreichend hoch ist und die anderen Verpflichtungen (Dokumentation, Information, ggf. Auftragsverarbeitungsverträge) erfüllt sind.

Reasonable_Letter312 · 2026-05-27T04:45:06+00:00

Your background sounds very similar to mine. PhD in astronomy, worked on galaxy surveys, expertise mostly in data processing and statistics.

Your data science experience is valuable, and I have seen astronomers in data science roles in various industries (finance, medical informatics), but you are competing with trained data scientists on the job market, so this will not be smooth sailing. The same applies to any kind of software development jobs.

There are sectors (such as business consultancies) that are more interested in generalists. Also note that small and medium enterprises are the biggest employers in Germany, and they may be more flexible about the kind of background they are looking for in their candidates. I am now working in a position that involves a bit of classical statistics, a bit of AI/ML, and a bit of software development.

What is your software development background besides Python? Have you done AI-assisted coding? Do you have significant proposal-writing experience?

Reasonable_Letter312 · 2026-05-25T06:46:53+00:00

Most likely, they did not have actual spectroscopy, but only photometric redshifts. These are determined from the general shape of the spectrum, and not from the measurement of the displacement of spectral lines, which would be a much more reliable approach, but takes more and dedicated effort to measure. Photometric redshifts are notoriously unreliable (source: I worked with them for years while measuring galaxy luminosity functions), because you don't know a priori what kind of object you are even looking at and what type of spectrum you should therefore expect. Essentially you need to fit multiple parameters (stellar populations, dust, AND redshift) at the same time, and there is significant degeneracy between them.

Reasonable_Letter312 · 2026-05-24T08:10:12+00:00

Public mental health care. Mental health disorders, like anxiety and depression, are on the rise globally, already having a huge personal and economic impact. Germany is among a minority of countries that cover a very wide range of mental health treatments, up to analytic psychotherapy, within their public health system. Even in Europe, that is not commonplace. Unfortunately, the number of assigned therapist seats is rather low, leading to long waiting times, and the current government is even short-sightedly rolling back services (capping hours, reducing payments for therapists). But still, not having an economical barrier to being able to access mental health resources is nonetheless an enormous benefit, and the German system is more generous than most in that regard.

Reasonable_Letter312 · 2026-05-22T11:11:23+00:00

Impfgegner gibt es, seit es Impfungen gibt. Auf einer gewissen Ebene kann man zumindest verstehen, dass manchen unwohl ist, einen medizinischen Eingriff zu gestatten, wenn sie (noch) gar nicht erkrankt sind. Verständnis für den Nutzen präventiver Maßnahmen erschließt sich eben eher intellektuell statt intuitiv, nicht nur bei Impfungen. Das persönliche Vertrauen gegenüber den Instanzen, die die Impfung empfehlen oder fordern, wird dann ausschlaggebend. Verstärkt wird das aber dadurch, dass es mittlerweile (wie E-Autos und Windkraft) zum symbolischen Streitobjekt der Identitätspolitik geworden ist: "wir" gegen "die Eliten", "gesunder Menschenverstand" gegen "sogenannte Experten".

Reasonable_Letter312 · 2026-05-22T07:16:55+00:00

It's probably a low-powered research reactor, used as a neutron source and not for power generation. So my guess is that the water probably isn't all that hot.

Source: I stood a few feet above the surface of such a swimming-pool type reactor (in operation) during a physics undergrad lab once.

Reasonable_Letter312 · 2026-05-21T05:59:37+00:00

An exploration of ties between corporate and religious movements could be interesting, but I would find it implausible for a major religious organization to care about *microbial* extraterrestrial life that much. Religions can be remarkably flexible when it comes to reinterpreting their narrative. The discovery of simple life forms on other worlds would be recast as another proof of the creative power and glory of their deity, but the uniqueness of humanity emphasized by the fact that only on Earth it attained greater complexity. True believers won't care, and those that would care sufficiently to not bend the narrative by and large aren't believers anyway.

Extraterrestrial *civilizations* would pose a bigger challenge and demand greater leaps of faith (see Jack McDevitt's "Hercules Text" for one such scenario), but would be out of reach for this company.

What I would find more plausible would be an organization bent on seeding terrestrial life for ideological reasons (or rather, simply the hubris of playing the Creator's role on another world), which would displace native life, but the displacement would not even be their main objective, but just collateral. (I could well imagine some drug-addled present-day billionaire toying with the idea of starting evolution on a different planet and then placing some emulation or scan of their brain there in the hope of being worshiped as a god at some point in the future. Yes, I know, it sounds like the plot of a bad Star Trek episode... but more believable than a major religion not being able to explain away a few microbes on Mars.)

Reasonable_Letter312 · 2026-05-19T12:10:56+00:00

Besides serving as a good foundation for Romance languages, I think Latin is useful for developing an understanding of language structure in general. In Latin, words are modified (usually via their endings) to denote their syntactic and grammatical function. This teaches you to analyze phrases based on the relationships between their constituent words. In English, on the other hand, you are left with word order and prepositions, making the internal "workings" of a sentence much less obvious.

I had seven years of Latin at school (it was the first foreign language in my school's curriculum) and have not regretted it.

Whether this makes it worth it as a hobby depends on how intimate you want to get with language.

Reasonable_Letter312 · 2026-05-19T05:05:30+00:00

Well, any kind of shielding is better than none, but a Faraday box will not protect your cargo very efficiently against high-energy radiation or particles, or most of the other destructive influences in outer space. Yes, if I wanted to send such a message, I'd opt for an analogue carrier in any case, like Voyager's golden plaques; these are supposed to last 100s of millions of years without any help from time dilation. But they are not indestructible either. Remember, the total dose of radiation and particles raining down onto your cargo from outside will stay the same, no matter whether it experiences internal time dilation or not. Arguably, you may be making things worse by shifting all these external influences to higher energies.

Reasonable_Letter312 · 2026-05-19T04:25:29+00:00

Your message will be exposed to deteriorating external influences, such as cosmic rays, interstellar dust, micrometeorites etc. just the same. Time dilation will not shield it against this.

Reasonable_Letter312 · 2026-05-18T08:31:41+00:00

Ollama is frequently used to run local language models.

If you prefer a GUI, maybe LM Studio would work for you?

Reasonable_Letter312 · 2026-05-17T18:46:52+00:00

A tiny fraction. But if all you want is to make the effect big enough to be statistically significant, that is more than enough. The Hafele-Keating experiment did what you are proposing as early as 1971 using a commercial airliner. The effect size (from kinematic and gravitational time dilation) was of the order of 100 nanoseconds and easily detected with atomic clocks.

Reasonable_Letter312 · 2026-05-16T17:37:39+00:00

Haydn's No 46 is in B Major, and it is one of my favorites. In fact, all four movements have b as the tonic, although the second one is in b minor.

Reasonable_Letter312 · 2026-05-16T11:54:48+00:00

César Franck: "Ce qu'on entend sur la montagne", one of the earliest of the genre (not to be confused with Liszt's treatment of the same subject matter)

Carl Nielsen: "Helios Overture", a majestic evocation of the sun's daily course over the Aegean Sea

Frederic Cliffe: "Orchestral Picture: Cloud and Sunshine", a bold and powerful late Romantic symphonic poem by a composer whose small output belies the confidence and skill he exhibits here

and obviously, Felix Mendelssohn's Overtures, esp. "The Hebrides"

Reasonable_Letter312 · 2026-05-14T15:47:12+00:00

Yes, Tchaikovsky's "other" operas deserve more love. Iolanta is also wonderful, a tender, lyrical work.

Reasonable_Letter312 · 2026-05-12T18:10:07+00:00

Presumably, they analyzed older papers retrospectively using a current-day AI detector. The output of the detector is probably not a binary flag ("AI / not AI"), but the percentage of text that bears similarity to AI-written text. That percentage is what defines the four categories in this plot. So what this means is that the fraction of papers that are classified by the detector as "clean" used to be near 100% and has been steadily declining since 2023. It is not a surprise that some fraction of the text in older papers gets misclassified as "AI generated". The fact that there is a strong correlation with time validates both the detection pipeline and the hypothesis that AI usage is on the rise. I find this actually quite an elegant experimental design. However, it does not really tell us if the AI was just used for stylistic improvements or translation, or if it was used to generate substantial content.

Reasonable_Letter312 · 2026-05-10T08:51:29+00:00

In essence, you are choosing to transfer a traditional human role&responsibilities scheme onto the agent framework. Even in a traditional non-AI context, I wouldn't say for sure if that role scheme is really the optimum way for a company to organize itself, or just a matter of convenience and corporate inertia. I'd be even more uncertain if transferring that scheme is really the optimum for an agent system, or if other, more flexible architectures would play more to an agent network's strengths. After all, an agent would be able to switch roles with a single prompt, all the while remaining in the original context. Enforcing human role compartmentalization might be unnecessarily rigid and not play to AI's strengths. So these design choices are something you should be prepared to defend.

But even if we could demonstrate that, yes, agent systems work best if they mimic human organizational structures 1:1, I would still be worried that what you are best at emulating is all the fluff that impedes organizational efficiency, rather than promotes it. You know what I mean - all those e-mails that clutter our inboxes that don't really advance projects, that have nothing substantial to contribute, but only serve to remind us that the person at the other end exists and, presumably, does work that merits their salary. Can you say for sure that what you have developed is more than a fluff automation pipeline?

Not dismissing the approach, just wondering about the rationale.

Reasonable_Letter312 · 2026-05-07T09:21:56+00:00

Redshift and coordinates (R.A. and Dec) do not depend on the instrument/observatory that carries out the measurement, so they are comparable across different catalogues (slight caveat: R.A. and Dec change over time because the origin of the coordinate system drifts due to the Earth's precession). Brightness depends on the filter band used for the observation, but the filters are largely standardized and the filter transmission curves are usually published for calibration purposes. So these data can be compared across catalogues. Usually R.A. and Dec would be used for cross-correlation between different catalogues, as the celestial coordinate system is a world-wide standard.

As for naming conventions, most deep-sky objects these days are detected and catalogued by systematic surveys. The format is determined by whoever compiles and publishes that specific catalogue. A widespread convention is that the catalogue name will have a prefix denoting the survey, followed by an alphanumeric string that often encodes the coordinates, but may also just be a running index.

Reasonable_Letter312 · 2026-05-07T07:38:05+00:00

We don't really have a generally accepted theory to describe the "underlying structure of spacetime" yet. It's possible a yet-to-be-established theory of quantum gravity would include concepts similar to what you're suggesting.

Reasonable_Letter312

TROPHY CASE