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Keyshon The End of the Roman Empire Wasn’t That Bad

Peter Brown and Walter Scheidel are indeed real historians (Brown of "Late Antiquity" and Scheidel of the Roman Empire). Not everything they're quoted as saying is necessarily that solid, though. For example, if Scheidel is really attributing "the dawn of the university" to the fall of the Western Empire, then he's eliding about seven or eight hundred years. (Fall of Western Empire: 5th Century; dawn of universities: 12th or 13th Century.)

Keyshon The End of the Roman Empire Wasn’t That Bad

advances made during the early middle ages, because it needs to ignore those advances in order to make its claim. The simple fact that there were many advances in the fields of engineering, metallurgy, architecture, transportation, mathematics and others

I would specifically question the argument that were "significant advances" in mathematics in the area of the former Western Empire in the early medieval period. There were advances in the Islamic lands, but Western Europe was mostly stuck with Boethius's 6th Century summaries. The Arabic/Islamic advances (and the rediscovery of much of ancient Greek mathematics) did not really spread to Western Europe until the 12th Century, when you start getting translations into Latin of mathematicians like Euclid and al-Khwarizmi.

Keyshon The End of the Roman Empire Wasn’t That Bad

the church rejected it because it did not fit observations (the ultimate scientific reason).

No, the Church rejected heliocentrism because it clashed with scripture, and because Giordano Bruno had promoted it, so they associated it with heresy. Their argument was that it was OK to use heliocentric models purely as calculational devices, as long as one did not attempt to argue that it somehow reflected reality. The Church did not begin to formally accept heliocentrism until the 1750s, when they dropped the general prohibition against heliocentric books. The prohibition against Copernicus's book De Revolutionibus was only rescinded in 1835.

Keyshon The End of the Roman Empire Wasn’t That Bad

I would be skeptical about attributing too much to a newspaper report about an unpublished conference presentation, particularly as the reported increase is only 2 years (with no quoted uncertainties).

From this review article about post-Roman Britain: (https://onlinelibrary.wiley.com/doi/full/10.1111/j.1478-0542...)

"There is just no alternative to the conclusion that urban life ceased in most places by the mid‐fifth century, doomed by the virtual cessation of market activity, a climatic downturn which arguably destroyed the capacity of agriculture to deliver a reliable surplus, the collapse of state funding of officialdom and the soldiery, and the impact on trade of an era of barbarian raiding and internecine warfare."

Of course, since historically urban life expectancy has tended to be less than small-town and rural life expectancy, it's even possible that the de-urbanization of Britain did lead to a slight increase in life expectancy.

Keyshon The End of the Roman Empire Wasn’t That Bad

> the article hints at that

Unintentionally, perhaps. Really, this is an indication of the article's incoherence and sloppiness. It purports to be mostly about the aftermath of the collapse of the Western Empire in the 5th Century, and how this supposedly cleared the way for assorted awesome developments (five or six hundred years later). So the transition from Republic to Empire is irrelevant to the argument.

Keyshon The End of the Roman Empire Wasn’t That Bad

James Fallows is not a "professional historian", he's a journalist. Go ahead and argue with him; this is a very confused and silly article.

Keyshon What’s Up with LIGO?

But, as critics have pointed out correctly, the LIGO alert for this event came 40 minutes after NASA’s gamma-ray alert. For this reason, the event cannot be used as an independent confirmation of LIGO’s detection capacity.

Leaving aside the question of why there was a "delay", this is a fundamentally incoherent and meaningless critique on Hossenfelder's part. (Well, unless you want to take seriously the implication that the LIGO team could have used that 40 minutes to create a fake alert to go with the gamma-ray alert.)

As long as we have reason to believe (and we do) that the LIGO data record is valid, then when the alert was issued is irrelevant to whether it is "an independent confirmation of LIGO's detection capacity."

(The detection of neutrinos from Supernova 1987A was reported about two weeks after the optical detection of the supernova [optical detection: 24 February 1987; Hirata et al. Kamiokande paper submitted to Physical Review Letters in early March of 1987]. So I guess we should question whether neutrinos from SN 1987A were ever really detected?)

Keyshon What’s Up with LIGO?

As an indicator of the slapdash quality: she calls into question the neutron-star merger by saying, "Furthermore, the interpretation of this signal as a neutron-star merger has also been criticized."

But if you follow the link in that statement, it leads to a previous post of hers (from November 16, 2018), which concludes:

"Basically, I feel reassured in my conclusion that you can safely ignore the Italian paper [which questions the NS-merger]."

It's more than a little odd to imply that there has been potentially meaningful criticism of GW170817 by referring to a post in which she herself concluded that there hasn't.

Keyshon Entropic Gravity

MOND famously (notoriously?) cannot explain the observed motions of galaxies within groups and clusters (the oldest known evidence for dark matter). Even if you assume MOND is true, the galaxies are moving too fast, so you need an extra source of, well, dark matter.

Keyshon Entropic Gravity

I apologize for the snark, but, really, you are both on the internet...

http://letmegooglethat.com/?q=data+for+galaxy+rotation+curve...

(The fourth link, for example -- http://astroweb.cwru.edu/SPARC/ -- has both observed rotation-curve data and computations of expected rotation curves.)

Keyshon Entropic Gravity

It generally works a bit better if you say something like, "Hmm... it seems like this approach would be wrong, for this reason that just occurred to me. Am I missing something? Or: How do people in the field actually do it, so as to avoid this error?"

If, on the other hand, you assume they must all be stupider than you are and say things like "That is exactly one of the mistakes I suspect keeps being made", then you're basically saying, "I'll bet none of the hundreds or thousands of people working in this field for decades have ever thought of this one point that just occurred to me!" The latter is, shall we say, rather unlikely.

(In point of fact, Newton's shell theorem generalizes to the case of axisymmetric, flattened spheroids with homeoidal density distributions, a result that was derived by Laplace and others in the 18th and 19th Centuries. Which means that disks do behave somewhat like spheres.)

To get a sense of what's really involved, you could look at something like Brandt's 1960 paper, and then some of the papers that cite it (including some of the classic early papers by Vera Rubin and collaborators), to get an idea of how much more sophisticated than an simple Keplerian rotation curve:

https://ui.adsabs.harvard.edu/abs/1960ApJ...131..293B/abstra...

Keyshon Entropic Gravity

"My other issue is that in discussions of rotation curves, I keep seeing reference to Kepler, which simply shouldn't apply. Where can I see the math behind the "expected" curve"

"Keplerian" in this context is an approximate term. It refers to the fact that most of a galaxy's visible mass is centrally concentrated, and so as you get further and further away, with virtually all of the mass inside whatever distance you're at, the rotation curve should converge on a true Keplerian one, because the difference between the effect of the true mass distribution and one where all the galaxy's (visible) mass is concentrated in a point at the center gets smaller and smaller.

Actual published fits to galaxy rotation curves always use the measured visible-mass distribution for a given galaxy to compute the non-dark-matter curve. No one working in this field is confused about this.

Keyshon Entropic Gravity

For modeling individual galaxies, that's more or less correct. (Of course, the same applied to things like MOND: "hey, if Newtonian acceleration is tweaked with this interpolation function and that free parameter, it will explain the observation".)

In a large-scale, statistical sense, the answer is: initial quantum fluctuations (as seen in the Cosmic Background Radiation) + gravitational collapse and fragmentation in an expanding universe. Simulations done under these assumptions have done an increasingly good job of describing the general distribution of dark matter, and the typical statistical distribution within galaxies.

This is why it's good to do independent fits of dark matter distributions to galaxies: it provides something you test the simulations against. After all, if the individual-galaxy fits say dark matter generally has distribution X, but the simulation say that gravitational collapse and mixing should almost always produce something different, then you know you've got a problem.

"If it interacts with visible matter gravitationally then why doesn't it take on the same distribution?" Because visible matter interacts with itself via radiation and hydrodynamics (e.g., gas pressure). So it gets pushed around in ways the dark matter can't. These forces can be much stronger than gravity in some circumstances (gravity, after all, is the weakest fundamental force), so the gas atoms, ions, electrons, etc. experience forces the dark-matter particles do not.

Keyshon Why didn't the Romans contribute much to mathematics?

No, Baghdad was located in the heart of the former Persian (Sassanian) Empire, a mere 35 km from the site of the Sassanian capital (Ctesiphon). Although the whole area gradually became Arabized, at the time it was still significantly Persian.

(Frankly, I doubt we know where Al-Khwarizmi was educated. We know he was originally from what's now Uzbekistan, and that he ended up in Baghdad, but not much more than that.)

Keyshon Why didn't the Romans contribute much to mathematics?

As someone else pointed out, this does nothing to explain why Roman-era mathematics seems to have stagnated, compared to the Classical and Hellenistic Greek mathematics that preceded it. Greek mathematicians didn't have access to Indian/Arabic numbers either. (And it mistakes "using numbers" for "mathematics" -- much of Greek mathematics was focused on geometry.)

Keyshon Why didn't the Romans contribute much to mathematics?

The Emperors were stripped of power back in the 12th Century, after the Genpei War and the formation of the Kamakura Shogunate. They remained stripped of power for almost the next seven hundred years; the power struggles were about who would get to be Shogun.

(The logic of the Meiji "Restoration" was essentially "Let's get rid of the archaic Shogunate system that has dominated Japan in one way or another for the last seven hundred years, and pretend we're handing power back to the Emperor where it really belongs.")

Keyshon Why didn't the Romans contribute much to mathematics?

There's an excellent book on the subject called The Fall of Rome and the End of Civilization, by Bryan Ward-Perkins. It includes a detailed overview of the archeological evidence, which shows a very clear and dramatic decline in the economy and living standards -- and some areas of technology -- between circa 350 and 600 in the Western Empire. (And the recovery afterwards took centuries.) The Eastern Empire, interestingly, doesn't show any signs of a similar decline until the 7th Century.

For example, peasant households in Italy at the height of the empire had a wide variety of well-made pottery, some of it originating from production centers hundreds of miles away, along with tiled roofs; after the collapse, the variety and quality of pottery was greatly reduced, and tiled roofs disappear. (Tiled roofs provide better protection against rain, are less flammable, and require less maintenance and rebuilding than wooden shingles or thatch; but they also require large kilns, lots of clay and fuel, and a good transportation network.)

And ice cores from Greenland show extensive metalworking going on in Western Europe (in the form of copper and lead pollution carried through the air) during the Roman Empire; after the collapse of the Western Empire, the pollution levels don't return to Roman-era values until the 16th Century.

Keyshon Notre-Dame came closer to collapsing than people knew

From the article: "First it gave a shorthand description of a zone — the cathedral complex was divided into four — that read “Attic Nave Sacristy.”"

So the entire zone is called "Attic Nave Sacristy", and from that all you know is that there's apparently a fire somewhere in that zone -- could be on the floor of the nave, could be in the cathedral attic, could be somewhere in the sacristy building (even in the attic of the sacristy).

The irony is that you've made a version of the same mistake that either the security employee or the cathedral guard made -- assuming a specific location within that zone. Yours ("the nave attic") happens to be correct; one or both of them assumed it was "the attic of the sacristy building".

Keyshon Notre-Dame came closer to collapsing than people knew

It really meant something more like "the part of the cathedral complex containing the cathedral's nave, the cathedral's attic, and the sacristy building".

The real problem was that both the main cathedral and the sacristy (a separate building adjacent to the cathedral) had attics; either the security employee got confused and told the cathedral guard to check the sacristy's attic, or the guard got confused and decided to do that.

Keyshon Galaxy Simulations Offer a New Solution to the Fermi Paradox

You don't want a supernova going off too close. We have been lucky to avoid that. Our odds were greatly improved by the fact that we spend most of our time out of the galactic plane, away from other stars that could be about to go boom. This is an unusual orbit.

Not really. The amplitude of the Sun's vertical motion is about 100 parsecs (~ 300 light years), but since the main ("thin") stellar disk has a vertical exponential scale height of about 300 parsecs, the local density of stars at the top/bottom of the Sun's orbit is only about 30% less than when the Sun is crossing through the midplane. (And this isn't at all an unusual orbit.)

What makes a real difference is being relatively far out in the disk from the galactic center: if we were ten times closer to the center, the local density would be almost 100 times higher, and you might indeed have to start worrying about nearby supernovae.

Keyshon Hubble takes gigantic image of the Triangulum Galaxy

The first image [-7] is basically the same as the classic WFPC2 image jzl was referring to -- i.e., using the same mapping of emission-line filters to R, G, and B -- just using a newer camera.

Keyshon Hubble takes gigantic image of the Triangulum Galaxy

You absolutely are seeing individual stars in the Triangulum Galaxy (M33) in the zoomable image. The brighter "blobs" are a combination of foreground stars (i.e., stars in our own galaxy) and star clusters in M33, but the fainter points are almost all stars in M33 (a few may faint foreground stars or background galaxies and quasars).

This is no more mysterious than the fact that you can see individual (nearby, bright) stars with your naked eye when you go outside at night. The angular resolving power of your eyes (or of small telescopes) compared to the angular diameters of even nearby stars is terrible; nonetheless, you can still see them.

The key thing to understand is that objects which are too small to resolve will be blurred by the telescope/lens/eye (plus atmospheric turbulence if you're not in space) into a point spread function [https://en.wikipedia.org/wiki/Point_spread_function]. The light from each star is thus spread out over multiple pixels in a pattern which is basically the same for all the stars, varying only in total brightness and thus detectability; for really bright stars, the light in this pattern can be traced out over a significant fraction of the entire image. This includes features like the diffraction spikes; we don't see these for stars in M33 only because they're too faint to register.

Keyshon Who Were the Mamluks?

China was extremely expansionist. It's just that over time they successfully assimilated (or suppressed) most of the regions they conquered, to the point where they and most other people think of them as naturally part of China (ignore what the Tibetans, Uighirs, and Mongols say, they're just disloyal).

That's a bit like saying, "The US never grew much beyond its current borders, so it wasn't expansionist."

Keyshon Earliest images of the moon were better than people realised

In fact, there’s an comment to the effect that the actual start time is about a million and a half seconds after the moon landing — which means the original time system is Unix-based...

Keyshon Probing Planets in Extragalactic Galaxies Using Quasar Microlensing

To be honest, I think "planets in other galaxies" would be better (since "extragalactic galaxies" sounds a bit like "galaxies outside of galaxies").

Keyshon Tea if by sea, cha if by land: Why the world only has two words for tea

There's a more comprehensive version of this story at linguist Dan Jurafsky's web site (it can also be found in the book by Jurafsky mentioned by aniket_ray): http://languageoffood.blogspot.com/2014/08/tea-if-by-sea.htm...

Keyshon The science that’s never been cited

That’s only true in some areas (e.g. some biological fields). In other areas (e.g astronomy or much of physics), it’s decreasing order of contribution. In mathematics, the author list is usually alphabetical.

Keyshon What a debate about p-values shows about science

Your examples weren't so much contrived as incoherent, to the point where I begin to suspect you don't really understand NHST.

"if I try to decide that native Hawaiians are US citizens, and the null hypothesis is that they are, but since only ~0.2% of total US population is native Hawaiian, NHST would conclude that native Hawaiians aren't US citizens."

So what is the observation in this case, and what would the corresponding prediction from the null hypothesis be? The observation that "0.2% of the US population is native Hawaiian" has no relation to your claimed null hypothesis at all.

The rest of your objection seems like one of those confused arguments trying to rule out basic reductio ad absurdam ("but if X really isn't true, then your arguments about seeing or not seeing the consequences of X have no basis!").

(And the central limit theorem has nothing to do with null hypothesis testing: you can do NHST with completely non-Gaussian statistics.)

Keyshon Astronomers have found the stars responsible for an explosion recorded in 1437

Their conclusion in the OP was AIUI that _many_ stars produce novae serially. So we should surely be able to match series of novae (along a stars trajectory).

The time between classical nova outbursts is estimated to be on the order of 10,000 years, so the previous outburst of this particular nova was probably long before the development of writing.

In addition, it likely takes only a couple of thousand years for the expanding shell of gas to fade from visibility, so it's probably not possible to find the traces of previous outbursts along the trajectory (although that would be cool).

Keyshon Astronomers have found the stars responsible for an explosion recorded in 1437

Binary systems that produce classical novae (like this one) don't "die". Moreover, the star that they identified is a confirmed binary system with an evolved late-type star and a white dwarf, which is precisely the kind of system that you need to produce a classical nova. (Part of the paper is data demonstrating this, including the orbital period -- about half a day -- of the system). In addition, it has produced minor ("dwarf nova") outbursts several times in the last century, which is what you'd predict for a system in the "hibernation" period between classical nova outbursts.

So it's not just the spatial match-up -- there's a lot of additional supporting evidence that this binary system is in fact the one what done the deed.