September 2021 Archives

Thursday, September 30, 2021

CONTINUITY: The Rise and Fall of Teletext

Posted at 14:23 Permalink

TRACKING WITH CLOSEUPS: “In Event of Moon Disaster” Deep Fake Film Wins Emmy

The film was announced as the winner in the “Outstanding Interactive Media: Documentary” category.

Here is the full film.

The documentary “To Make a Deepfake” explains how it was made.

For more information, visit the project's Web site,

Posted at 13:28 Permalink

THE HAPPENING WORLD: Cooling High-Performance Microprocesors

In the 1960s and 1970s, supercomputers were all about cooling. High speed circuits, in particular emitter-coupled logic (ECL), which ran their transistors out of the saturation zone in the interest of fast switching, were famously power-hungry and consumed current constantly, not just when switching. Consequently, they took a lot of power and dissipated abundant heat, which had to be efficiently removed from the components. Some amazing schemes were used, such as the IBM thermal conduction module and the Cray-2, which bathed its logic circuits in circulating Fluorinert fluid cooled in an external “waterfall”.

The advent of power-stingy CMOS circuitry, which consumes almost no power except when actually switching, and the benefits of the Dennard scaling theorem as circuit geometries shrunk over the years, halted the correlation of power consumption with computing speed for decades, but around 2006 the end of the road was reached, resulting in cessation of rapid increases in clock speed and an increasing focus on multi-core and other parallel architectures. Since then, heat has returned as a major issue in high performance computing.

As the next generation of processors comes into view, the power dissipation limits of forced air and even water cooling by conduction from conventional packages are reaching their limits. This video surveys approaches to coping with this challenge, including piping water right into processor chips to cool them by direct contact with the back side of the silicon substrate,

Posted at 11:19 Permalink

CONTINUITY: Tour of the International Space Station Tranquility (Node 3) Module

The tour of the International Space Station continues with NASA's Tranquility module, also known as Node 3, launched to the station in February 2010 by space shuttle Endeavour on the STS-130 mission. Tranquility is the module to which the viewing Cupola is attached, but it is not shown in this visit recorded during orbital night when there would have been nothing to see. This tour, presented in 360° immersive video (hold down your mouse button within the image and move the pointer to pan and tilt your viewpoint), is led by European Space Agency astronaut Thomas Pesquet. The audio is in French, with English subtitles. (If the subtitles are not automatically enabled, click the “CC” box at the bottom to turn them on.)

Posted at 10:28 Permalink

Wednesday, September 29, 2021


The .22 Eargesplitten Loudenboomer cartridge was developed by P. O. Ackley for Guns & Ammo magazine. Its sole goal was to produce a muzzle velocity of at least 5000 feet per second (fps) or around 1524 metres/second, in excess of Mach 4.2. The cartridge was created by necking down a .378 Weatherby Magnum case to accept a 3 gram .224" (5.56 mm) bullet.

In ballistic testing, the round never achieved the target muzzle velocity, topping out at 4600 fps (1500 m/sec) and a muzzle energy of 3,185 joules, which is almost twice that of the 5.56×45 NATO cartridge used by the AR-15, M-4, and similar rifles, which fires a bullet of comparable size and mass.

It is not clear what would have happened to the bullet immediately after leaving the barrel. At Mach 4, heating and aerodynamic forces would have been extreme, and it's possible a lead bullet might have melted shortly after exiting the muzzle and been dispersed into a cloud of droplets. In any case, with such a light bullet and supersonic drag forces,, the projectile would rapidly lose velocity and energy. But this was intended to set a record, not be practical for anything.

Posted at 15:23 Permalink

THE HAPPENING WORLD: Double-Charm Tetraquark

Here are the research papers announcing and describing this discovery:

Posted at 13:52 Permalink

CONTINUITY: From 1959—“The Art of Gold Beating”: Making Gold Leaf

The thickness of gold leaf is around 100 nanometres, which is the wavelength of near infrared light and only around 2000 gold atoms thick. If you hold a sheet of gold leaf up to a bright light, you'll see light transmitted through it, with a shade of green-blue. I used to think this was an interference effect due to the thickness of the leaf, but it's simply a result of gold reflecting predominately red and green light, giving it its characteristic mellow glow (thanks to special relativity), with the unabsorbed blue and green wavelengths passing through the thin sheet.

Posted at 11:56 Permalink

CONTEXT: Soyuz MS-18 Repositioned to Nauka Module on International Space Station

Yesterday, 2021-09-28, the Soyuz MS-18 spacecraft was undocked from the Rassvet module on the Russian segment of the International Space Station and flown around to the other side of the station where it was docked to a port on the new Nauka module, the first time that port was used. This frees the Rassvet port for the docking of Soyuz MS-19, scheduled to launch on October 5th. Since the Nauka port had not been previously used, the repositioning allowed it to be tested before both ports were required by the arrival of the new Soyuz. Even for such a brief maneuver, the Soyuz crew prepares as if for a return to Earth, as failure to re-dock, for whatever reason, would require they de-orbit and land in Kazakhstan.

This is a time lapse of the repositioning.

And here is the complete operation as it occurred (one hour and 14 minute video).

Posted at 11:24 Permalink

Tuesday, September 28, 2021

THE HAPPENING WORLD: To Be Fair, Who Hasn't Done This?

Posted at 14:27 Permalink

CONTEXT: The Long Road to Rocket Reusability

In related news, Starship SN20 lost a number of its thermal protection tiles in the nosecone area during a vent of the header tank yesterday.

Posted at 14:00 Permalink

CONTINUITY: The Great Jerusalem Artichoke Scam

The “weed that whips OPEC”. … “… Jerusalem artichokes were the antidote to global banking, OPEC, the Trilateral Commission, the Rothschilds, the evils of Big Ag, and Ayatollah Khomeini.”

Posted at 13:03 Permalink

THE HAPPENING WORLD: Tesla Announces “Full Self-Driving” Beta 10.2—Prioritised by Customers' “Safety Rating”

Here is more about the Tesla “Safety Score” from 2021-09-25. One hopes a swarm of contingency fee lawyers are poring over Tesla's customer agreements and licenses to see if this panopticon surveillance and coercion to enable it violates the “shrink wrap license” shield Tesla has erected against liability and failure to perform under claims of “self-driving”.

Posted at 11:50 Permalink

TRACKING WITH CLOSEUPS: Gigantiops destructor—The Celebrated Jumping Ant of Amazonia

Here is more on Gigantiops destructor. How do they do it?

Posted at 11:18 Permalink

Monday, September 27, 2021

Add category: Cat Earth

Perhaps this explains what is happening to Australia.

Posted at 14:51 Permalink


Posted at 13:42 Permalink

CONTEXT: Did an Asteroid Impact Destroy the Biblical City of Sodom?

Yes, I am well aware of Betteridge's Law.

A recent paper published in Nature, “A Tunguska sized airburst destroyed Tall el-Hammam a Middle Bronze Age city in the Jordan Valley near the Dead Sea” (full text [PDF]), argues (from the abstract) “… in ~ 1650 BCE (~ 3600 years ago), a cosmic airburst destroyed Tall el-Hammam, a Middle-Bronze-Age city in the southern Jordan Valley northeast of the Dead Sea. The proposed airburst was larger than the 1908 explosion over Tunguska, Russia, where a ~ 50-m-wide bolide detonated with ~ 1000× more energy than the Hiroshima atomic bomb. … Tall el-Hammam may be the second oldest city/town destroyed by a cosmic airburst/impact, after Abu Hureyra, Syria, and possibly the earliest site with an oral tradition that was written down (Genesis).”

How plausible is this? Well, we know that the Tunguska event occurred, and its interpretation as having been caused by a cosmic impactor that disintegrated in the atmosphere is consistent with analysis of smaller, more recent, and better documented impacts such as the 2013 Chelyabinsk meteor. The analysis in the Nature paper covers a wide spectrum of scientific disciplines including geology, archaeology, bioarchaeology and analysis of human skeletal remains, mineralogy and shock formation, agronomy, and small body planetary science. But in this age of widespread and deep corruption in academic and institutional science (as the replication crisis spreads from the squishy into the harder sciences), publication in a prestigious venue does not ensure the reliability of the work, and specialists in the relevant fields have been quick to respond, “Not so fast.”

For example, Mark Boslough, four of whose papers on the Tunguska event were cited as references, responded on Twitter as follows:

beginning a long thread which you can read by clicking the message above.

Scott Manley surveys the claims in the paper and other objections raised to it in this video and suggests that readers “Take these claims with a pillar of salt.”

Posted at 12:21 Permalink

CONTINUITY: Galileo Observed and Drew an Occultation of Θ Libræ in 1610

Posted at 11:53 Permalink

TRACKING WITH CLOSEUPS: The Subtle Physics of Bowling

Did you know that bowling lanes are not only oiled, that the oil is responsible for the behaviour of the ball, but that there are dozens of different ways to do it?

Posted at 11:23 Permalink

Sunday, September 26, 2021

THE HAPPENING WORLD: Tesla “Safety Score” to Spy on Customers' Driving Behaviour, Phone Home

Some Tesla owners think this is just great.

Why, it's “Almost like a credit score!” (bang in original). Indeed…just like a social credit score, to be precise. Perhaps if your score indicates “antisocial driving” your Tesla will only allow you to drive back and forth between your residential pod and socialist labour cubicle.

“They'll go into debt to buy their own shackles” — Kelvin R. Throop

Posted at 12:37 Permalink

THE HAPPENING WORLD: Atlas V Landsat 9 Launch

The Webcast of the launch is scheduled to start at 17:30 UTC on Monday, 2021-09-27.

Posted at 12:28 Permalink

CONTEXT: Cryptocurrency-Trading Hamster Outperforms the Standard&Poor's 500

Those with a grasp of history and a nose for irony will note that the hamster's name is “Mr Goxx”, who has his own Twitch page and livestream. Take that, potty-mouthed “stonks” day trader!

Posted at 11:58 Permalink

THE HAPPENING WORLD: Weekly Space Report: Starbase Claw and Tank Farm, FAA Environmental Assessment, Inspiration4 Returns, and Landsat 9 Launch

Posted at 11:24 Permalink

Saturday, September 25, 2021


Posted at 14:34 Permalink

THE HAPPENING WORLD: Scientific American: “Jedi” are “prone to (white) saviorism and toxically masculine approaches to conflict resolution”

Scientific American, founded in 1845, was once a paragon of science communication to the intelligent layman. After it was sold to the Germans in 1986, it began an intellectual decline which was initially gradual and then increasingly precipitous. By the early 1990s I had taken to calling it “Scientific Enquirer”, as its pages were increasingly filled with midwit sensationalism and advocacy for collectivist policies. I let my subscription lapse in the mid-90s and have since rarely seen a citation of anything in it I'd be inclined to read. Now, they have apparently gone fully “woke”. Just read this piece, under the rubric “Inequality: Opinion”, titled “Why the Term ‘JEDI’ Is Problematic for Describing Programs That Promote Justice, Equity, Diversity and Inclusion“, which has sufficient zingers per paragraph to help you meet your guffaw quota for the day. For example, “The space opera franchise has been critiqued for trafficking in injustices such as sexism, racism and ableism. … Star Wars arguably conflates ‘alienness’ with ‘nonwhiteness,’ often seeming to rely on racist stereotypes when depicting nonhuman species. The series regularly defaults onto ableist tropes, memorably in its portrayal of Darth Vader, which links the villain’s physical disability with machinic inhumanity and moral deviance, presenting his technology-assisted breathing as a sinister auditory marker of danger and doom. What’s more, the bodies and voices centered in Star Wars have, with few exceptions, historically been those of white men.” (Hello—Princess Leia, Chewbacca, C3PO, and R2-D2 are “white men”?)

Sic transit gloria Jedi. It seems to me that it's Scientific American that is “problematic” and “arguably” a disgrace to its distinguished history.

Posted at 12:47 Permalink

CONTEXT: Concorde Crash in July 2000—What Happened to Air France Flight 4590?

Posted at 12:05 Permalink

CONTINUITY: Repairing a Pressurised, Oil-Filled Underground Power Transmission Line

Posted at 10:53 Permalink

Friday, September 24, 2021

CONTEXT: Observing the Formation of Massive Stars with Radio Telescopes

Posted at 13:28 Permalink

TRACKING WITH CLOSEUPS: Maze Solving by Particle Diffusion

Dumbest way? Well, massively parallel search is how biology solves all kinds of problems and it seems to work very well. And, looking backward at it, it looks like teleology or design.

Posted at 12:56 Permalink

CONTEXT: Meteor Crater in Arizona—A Lunar-like Impact Crater on Earth

The impactor is estimated to have been an iron-rich asteroid around 50 metres in diameter, which released around 10 megatons TNT equivalent energy when it struck the Earth at 12.8 km/second. The energy is comparable to that of the Tunguska impact, but the latter formed no crater because it was probably a stony rubble pile which disintegrated in an airburst instead of an nickel-iron bullet that reached the surface.

When I was a kid, all of the books called this feature “Barringer Meteor Crater” after Daniel M. Barringer, who was one of the first to suggest it was an impact crater and not volcanic. Barringer later purchased the crater in hopes of mining iron from it, and the Barringer family still owns the crater today, There is a Barringer Crater, but it's on the far side of the Moon and 58 times bigger than the one on Earth.

Posted at 11:58 Permalink

THE HAPPENING WORLD: Floating Point Benchmark: Raku (Perl 6) Language Added

Raku Mascot, Camelia I have posted an update to my trigonometry-intense floating point benchmark which adds Raku to the list of languages in which the benchmark is implemented. A new release of the benchmark collection including Raku is now available for downloading.

Raku has had a gestation period which may be longer than any other programming language to ever actually be released. Following the release of version 5 of Perl, Larry Wall began the process of designing its successor, dubbed, not surprisingly, “Perl 6”. This was around the year 2000, and design documents began to appear. Perl 6 was intended to be a major overhaul of the language, in which upward compatibility with existing code would be sacrificed where necessary to clean up some of the infelicitous syntax and semantics that Perl had accreted over the years and gave it a reputation of being, while powerful, expressive, and concise, ugly to read and confusing and error-prone to write.

Over the years, it became apparent that Perl 6 was a moving target, as many of the design documents superseded aspects of those which preceded them. Further, the landscape of programming languages was changing over time, with techniques such as functional programming, asynchronous concurrent processing, optimisation for vector and parallel architectures, and strong type checking to guard against common programming errors, coming into use and expected to be present in any new language to enter the arena.

Perl version 5, while once dominating the system administration tool application space, began to look increasingly long in the tooth, with newer entrants such as Ruby and especially Python being the tools of choice for new projects and programmers entering the job market. By 2019, it was judged that the language, while clearly descended from Perl, had evolved into something sufficiently different that a new name was called for, and Perl 6 was henceforth called “Raku”. Unlike Perl, whose operation was essentially defined by what the implementation did, Raku has a formal specification, allowing multiple implementers to build their own compilers and libraries for the language. At the moment, the most widely used and actively developed compiler is Rakudo, which is available for a variety of machines and operating systems.

I developed the Raku implementation of the floating point benchmark with Rakudo v2021.09, which implements Raku language specification v6.d, running on Xubuntu Linux version 20.04 LTS on a 64-bit Intel x86 architecture machine. I developed and benchmarked two separate versions of the program. The first was a minimal port of the existing Perl implementation of fbench. I simply fixed the code to accommodate changes in the language, but used none of the new features or program structuring tools introduced in Raku—I call this the "port" version. The second was a clean sheet Raku implementation based upon the object oriented architecture used by the C++ version and other modern language implementations such as Haskell, Scala, Erlang, Rust, and Go. This I call the "native" version, which uses Raku's object oriented features, strong typing, enumeration and constant types, and improved control structures to structure the code.

For timing comparisons, I used the C version, compiled with GCC version 9.3.0, which executed the C benchmark with a timing of 0.795 microseconds per iteration, and Perl version v5.30.0, which ran the Perl implementation at 32.1619 microseconds/iteration, or 40.46 times slower than C.

So, how does Raku stack up against these two mainstays of the systems programming world? Well, the good news is that it got identical answers to the eleven decimal places we validate. The bad news is that it is hideously, nay, appallingly slow. How slow? Well, the native version, where I used Raku the way I understand it is supposed to be used, and with the benefit of more than a day's experimenting, tweaking the code, and trying to understand what was going on, produced a timing of 163.42 microseconds per iteration, which is five times slower than Perl and two hundred and six times slower than C. And the minimal port, representative of what you get if you take an existing Perl program performing numerical calculations and migrate it to Raku by simply fixing the changes in language? It runs at a rate of 584.6 microseconds per iteration, which is eighteen times slower than Perl and seven hundred and thirty-five times slower than C.

What is going on here? First of all, I suspect that with development of a compiler and support libraries to support such an ambitious and, until recently, rapidly evolving language, priority has rightly been given to a complete and correct implementation of the language specification rather than optimisation. This is to be expected, and performance should improve over time, especially since language features in Raku such as strong typing and immutable and private variables should permit compiler optimisation better than that of Perl, whose heritage was a typeless, interpreted language.

But, for numerical programming (which, to be fair, was never Perl's strong point or a major application area), Raku's type system is distinctly odd and full of pitfalls for the incautious programmer unaware of what is going on under the hood. Raku has base numeric types of Int (arbitrary precision integers), Rat (arbitrary precision rational numbers [fractions]), Num (IEEE 754 double precision floating point), and Complex (complex numbers made up of two Nums). These, in turn, form “roles” such as Real, which encompasses the Int, Rat, and Num types. Now, this seems eminently reasonable. But now consider the following innocent statement:

  my Num $f = 0;

which declares a floating point variable and sets it to zero. What happens? Why, you get a fatal error message because you've tried to initialise a variable of type Num to an Int value, the constant zero. All right, you say, this seems a bit reminiscent of 1950s programming languages where every floating point number had to have a decimal point or an exponent, so you replace “0” with “0.0” and try again. (At least you don't have to repunch the card and hand your deck in across the counter then wait six hours to see what happens.) And the result is…blooie!—now you've tried to assign a Rat (rational number) to a Num, because everybody knows that “0.0” is just shorthand for “0/10” a rational number if anybody's ever seen one. The only way to get this statement past the compiler is to write the right hand side as “0e0” or “0.0e0”, which it deems to be a Num, or else explicitly convert the type with 0.Num or Num(0).

This may seem to be runaway pedantry which will probably get fixed in a future release, but it's actually more pernicious than you might think. Suppose you declare all of your floating point variables as Real, which encompasses all the (non-complex) numeric types. Now you can assign integers, decimal numbers, and floating point numbers with exponents to them without error. But if you assign a value like, say, 5895.944 (the wavelength, in angstroms, of the “D” spectral line used in evaluating optical designs) to your variable, it takes on a type of Rat, and calculations with it will be performed in library-implemented rational arithmetic, which is much slower than hardware floating point. And when you have a mixed-type expression involving a Num, it has to promote the value from rational to floating point, another slow operation. Note that this will happen if you so much as use a decimal constant in an expression involving floating point values. If you fail to tack an exponent onto it, everything slows down like molasses in mid-winter. Before I figured this out and explicitly typed all of the constants in my program, the “native” version ran more than three times slower than the results I report here.

A suitably smart compiler should be able to analyse the code and do much of this conversion at compile time, but the existence of polymorphic types such as Real may render this impossible in some cases. In any case, a programming language which requires such extreme fussiness to avoid painful and non-obvious speed penalties will have a steep hill to climb in competition with others that impose no such burden on their users.

The relative performance of the various language implementations (with C taken as 1) is as follows. All language implementations of the benchmark listed below produced identical results to the last (11th) decimal place. In the table below, I show Perl as 23.6 times slower than C, not the 40.46 times I measured as a part of these tests. I suspect this is due to the value in the table being measured on a 32 bit machine where the advantage of C-generated machine code is less than the 64 bit machine on which I ran this test.

Language Relative
C 1 GCC 3.2.3 -O3, Linux
JavaScript 0.372
Mozilla Firefox 55.0.2, Linux
Safari 11.0, MacOS X
Brave 0.18.36, Linux
Google Chrome 61.0.3163.91, Linux
Chromium 60.0.3112.113, Linux
Node.js v6.11.3, Linux
Chapel 0.528
Chapel 1.16.0, -fast, Linux
Parallel, 64 threads
Visual Basic .NET 0.866 All optimisations, Windows XP
C++ 0.939
G++ 5.4.0, -O3, Linux, double
long double (80 bit)
__float128 (128 bit)
MPFR (128 bit)
MPFR (512 bit)
Modula-2 0.941 GNU Modula-2 gm2-1.6.4 -O3, Linux
FORTRAN 1.008 GNU Fortran (g77) 3.2.3 -O3, Linux
Pascal 1.027
Free Pascal 2.2.0 -O3, Linux
GNU Pascal 2.1 (GCC 2.95.2) -O3, Linux
Swift 1.054 Swift 3.0.1, -O, Linux
Rust 1.077 Rust 0.13.0, --release, Linux
Java 1.121 Sun JDK 1.5.0_04-b05, Linux
Visual Basic 6 1.132 All optimisations, Windows XP
Haskell 1.223 GHC 7.4.1-O2 -funbox-strict-fields, Linux
Scala 1.263 Scala 2.12.3, OpenJDK 9, Linux
FreeBASIC 1.306 FreeBASIC 1.05.0, Linux
Ada 1.401 GNAT/GCC 3.4.4 -O3, Linux
Go 1.481 Go version go1.1.1 linux/amd64, Linux
Julia 1.501 Julia version 0.6.1 64-bit -O2 --check-bounds=no, Linux
Simula 2.099 GNU Cim 5.1, GCC 4.8.1 -O2, Linux
Lua 2.515
LuaJIT 2.0.3, Linux
Lua 5.2.3, Linux
Python 2.633
PyPy 2.2.1 (Python 2.7.3), Linux
Python 2.7.6, Linux
Erlang 3.663
Erlang/OTP 17, emulator 6.0, HiPE [native, {hipe, [o3]}]
Byte code (BEAM), Linux
ALGOL 60 3.951 MARST 2.7, GCC 4.8.1 -O3, Linux
PHP 5.033 PHP (cli) 7.0.22, Linux
PL/I 5.667 Iron Spring PL/I 0.9.9b beta, Linux
Lisp 7.41
GNU Common Lisp 2.6.7, Compiled, Linux
GNU Common Lisp 2.6.7, Interpreted
Smalltalk 7.59 GNU Smalltalk 2.3.5, Linux
Ruby 7.832 Ruby 2.4.2p198, Linux
Forth 9.92 Gforth 0.7.0, Linux
Prolog 11.72
SWI-Prolog 7.6.0-rc2, Linux
GNU Prolog 1.4.4, Linux, (limited iterations)
COBOL 12.5
Micro Focus Visual COBOL 2010, Windows 7
Fixed decimal instead of computational-2
Algol 68 15.2 Algol 68 Genie 2.4.1 -O3, Linux
Perl 23.6 Perl v5.8.0, Linux
BASICA/GW-BASIC 53.42 Bas 2.4, Linux
QBasic 148.3 MS-DOS QBasic 1.1, Windows XP Console
Raku 205.6
Rakudo v2021.09/v6.d, Linux, object-oriented rewrite
Minimal port of Perl version
Mathematica 391.6 Mathematica, Raspberry Pi 3, Raspbian

Download floating point benchmark collection

Posted at 11:36 Permalink

CONTINUITY: Boeing Starliner OFT-2 “Hangar Queen”—NASA Says “Will Likely Not Launch Until Next Year”

Boeing officials said last month that nitrogen tetroxide, an oxidizer consumed by Starliner maneuvering thrusters in combination with hydrazine fuel, leaked through Teflon seals in the valves. That is normal, Boeing officials said, but the nitrogen tetroxide reacted with water vapor that somehow made its way into the service module, creating nitric acid that corroded the valves and caused them to stick.

Twenty-four regulate the flow of oxidizer to the Starliner spacecraft’s thrusters used for in-space maneuvers. Boeing initially detected problems with 13 of the 24 oxidizer valves.

Officials will decide in a few weeks whether to repair the valves in the service module, or use a new service module for the OFT-2 mission. If Boeing goes with a new service module, the current service module might be repaired and used on a future mission, [NASA Space Operations Mission Directorate associate administrator Kathy] Lueders said.

Boeing officials said last month it was too early to know whether the valves might need to be redesigned, or whether ground teams could take more steps to ensure moisture does not get into the valves.

Reaction control thrusters using hydrazine and nitrogen tetroxide propellants are a technology that has been in use for more than six decades. The Boeing Starliner has been under development for more than one decade, and was originally planned to be operational in 2015. In 2014, still under development and not having flown, Starliner won a US$4.2 billion NASA contract to complete and certify the capsule and conduct one crewed flight by 2017. At the same time, SpaceX was awarded US$2.6 billion to do the same with their Crew Dragon spacecraft. To date Crew Dragon has completed four crewed space flights.

Posted at 10:42 Permalink

Thursday, September 23, 2021

CONTINUITY: Tour of the International Space Station Destiny Module

Continuing the tour of the International Space Station (ISS) conducted by European Space Agency astronaut Thomas Pesquet, we next come to the Destiny, or U.S. Laboratory, module, launched to the ISS as the first major U.S. science payload in February, 2001. It contains the operating station for the original robotic arm and is the core of the U.S./international segment of the station. The audio is in French, with English subtitles, which you may have to click on the icon at the bottom to enable.

Posted at 13:50 Permalink

TRACKING WITH CLOSEUPS: International Space Station Transits the Moon in Daylight

Posted at 13:04 Permalink

CONTEXT: Origin of NASA's Vehicle Assembly Building (VAB)

No, your memory isn't playing tricks on you. The big box was originally called the “Vertical Assembly Building”, as opposed to the adjacent Operations and Checkout Building where Apollo spacecraft were integrated and checked out before being mated vertically to the Saturn V booster. It was renamed “Vehicle Assembly Building” on 1965-02-03, anticipating its future use with other launchers.

Posted at 11:31 Permalink

CONTINUITY: HP 9825 Repair Part 12—Onward with the Keyboard, Display, and Printer Board

After replacement of all of its blown-out display chips, further diagnosis of the Keyboard/Display/Printer (KDP) module raises the disturbing possibility that its custom IC controller chip, which now might as well be made of a secret alloy of delirium and pandemonium, was destroyed by the power supply malfunction. Is it dead, or just compromised by further failures in the “glue” logic interfacing it to the rest of the board?

Posted at 10:41 Permalink

THE HAPPENING WORLD: Progress on the n-Queens Problem

These results set bounds on the number of mutually non-attacking queens on a n×n board, but do not provide an exact solution. Here are the two recent papers detailing the work.

Posted at 09:07 Permalink

Wednesday, September 22, 2021

TRACKING WITH CLOSEUPS: Graveyard of Empires—The 1842 British Retreat from Kabul

Posted at 14:44 Permalink

CONTINUITY: Dishwashers Again! Prewash Cycle and Why Detergent Tablets Are Expensive and Suboptimal

Posted at 13:00 Permalink

CONTEXT: Extreme Ultraviolet Lithography for Semiconductor Manufacturing, Parts 2 and 3 of 3

Concluding the series on the optical train of an extreme ultraviolet (EUV) system for exposing semiconductor wafers which began with Part 1, Part 2 discusses the properties of state of the art production lithography machines.

Part 3 explores how components of the optical train are manufactured to such demanding precision.

Posted at 12:41 Permalink

CONTEXT: Osaka's Sinking Airport

The sea isn't rising—the (artificial) island is sinking.

Posted at 11:15 Permalink

Tuesday, September 21, 2021

TRACKING WITH CLOSEUPS: The 6σ Neutrino Anomaly Nobody's Talking About: LSND and MiniBooNE

Here is more about sterile neutrinos and the MoniBooNE detector.

Posted at 13:32 Permalink

THE HAPPENING WORLD: UNUM 3.4: Updated to Unicode 14.0.0—Pregnant Men, Rejoice!

Version 3.4 of UNUM is now available for downloading. Version 3.4 incorporates the Unicode 14.0.0 standard, released on September 14th, 2021. Starting with this release, UNUM will identify itself with both its own version number and the Unicode version it incorporates, hence “3.4-14.0.0”. The update to Unicode adds support for five new language scripts, additional characters for several scripts, and 37 new emoji. There are a total of 144,697 characters in 14.0.0, of which 838 are new since 13.0.0. (UNUM also supports an additional 65 ASCII control characters, which are not assigned graphic code points in the Unicode database.)

This is an incremental update to Unicode. There are no structural changes in how characters are defined in the databases, and other than the presence of the new characters, the operation of UNUM is unchanged.

UNUM also contains a database of HTML named character references (the sequences like “<” you use in HTML source code when you need to represent a character which has a syntactic meaning in HTML or which can't be directly included in a file with the character encoding you're using to write it). There have been no changes to this standard since UNUM 2.2 was released in September 2017, so UNUM 3.4 will behave identically when querying these references except, of course, that numerical references to the new Unicode characters will be interpreted correctly.

You can download UNUM from the UNUM Documentation and Download Page. Source code is maintained on and may be downloaded from UNUM's GitHub repository,

Once you've installed UNUM 3.4, be sure to try:

    $ unum 0x1FAC3
      Octal  Decimal      Hex        HTML     Character   Unicode
    0375303   129731  0x1FAC3   🫃    "🫃"         PREGNANT MAN

pregnant-man-emoji-emojipedia-emoji-14-september-2021.png Yes, with version 14.0.0, the Unicode Consortium has joined the ranks of (or, perhaps, reconfirmed its membership in) the woke biology denialist mob, with the goal “to make the emoji keyboard more consistent and gender inclusive”. The “pregnant man character” probably didn't display in the line above as few platforms currently support it. Now that it has become enshrined in the Unicode standard, look (or look out) for it in an operating system update some time in the balance of 2021 or 2022.

Posted at 12:33 Permalink

CONTEXT: Hot Rocks: A Low-Tech Solution for Utility-Scale Energy Storage?

Posted at 11:29 Permalink

CONTINUITY: SpaceX: All Launches from Florida in Four Minutes and Twenty Seconds

We're not yet at “A Rocket a Day”, but we're getting there! That paper was written almost exactly 28 years ago, and envisioned a mass-produced two-stage rocket developed outside NASA with standardised payload interfaces. I did not, however, foresee first stage reusability, and expected LOX/hydrogen to be used to appease innumerate environmentalists. To convert dollar figures in that 1993 paper to today's kleptocurrency, multiply by 1.8.

Posted at 10:59 Permalink

Monday, September 20, 2021

THE HAPPENING WORLD: Fourmilab Pumpkin Head for Second Life Released

Fourmilab Pumpkin Head for Second Life

You've come to expect nothing but the most serious, professional software from Fourmilab, so I'm proud to announce the release of Fourmilab Pumpkin Head for Second Life, a jack-o'lantern (pumpkin carved with a face, lit from within) which may be worn as a head with both mesh and classic avatars, or used as a static decoration for Halloween and other occasions. It includes a script that allows you to configure its behaviour via chat commands, and provides features such as brightening the glow of the light when you're typing in chat.

The product is free, full (copy, modify, and transfer) permissions, including the ability to view and modify its script, able to be customised by commands in a notecard, and includes a development kit including textures, documents, and development log. Complete source code is maintained on and may be downloaded from GitHub.

Don't let Halloween sneak up on you. Sneak up on Halloween in the metaverse and say “Boo!” with Fourmilab Pumpkin Head.

Other Fourmilab products for Second Life

Posted at 14:15 Permalink

CONTEXT: Major Languages of the World

Although more than 7,300 languages are spoken by people in the world today, just 23 languages are the mother tongue of 4.1 billion people, around half the global population. Chinese is the largest language group, with more than a billion native speakers, but English is spoken in the most countries and is, by far, the most widely studied language by non-native learners.

Posted at 12:50 Permalink

CONTINUITY: Tour of the International Space Station Columbus Module

Our tour of the International Space Station continues with the European Space Agency's Columbus module, launched to the station in February 2008 by space shuttle Atlantis on the STS-122 mission. This tour, presented in 360° immersive video (hold down your mouse button within the image and move the pointer to pan and tilt your viewpoint), is led by European Space Agency astronaut Thomas Pesquet. The audio is in French, with English subtitles. (For some screwball reason, the code to automatically turn on the subtitles on YouTube may not work with this video. Click the “CC” box at the bottom to enable them.)

Posted at 11:43 Permalink

TRACKING WITH CLOSEUPS: Making Matter from Light—Demonstrating the Breit-Wheeler Process

The Breit-Wheeler process is one of the most fundamental manifestations of quantum mechanics and a direct demonstration of Einstein's mass-energy equivalence (E=mc2), but is extraordinarily difficult to demonstrate due to the large energy required and low probability of interaction. In the process, two energetic photons interact and are replaced by a particle and its antiparticle, an electron and positron in the simplest case. In a paper published in July 2021 in Physical Review Letters, “Measurement of e+e Momentum and Angular Distributions from Linearly Polarized Photon Collisions” (full text at ArXiv [PDF]) researchers at the STAR Collaboration reported observing the process in collisions of gold nuclei at the Relativistic Heavy Ion Collider.

Posted at 10:47 Permalink

Sunday, September 19, 2021

TRACKING WITH CLOSEUPS: Making Water Drops Spin with Hydrophobic Material

Posted at 13:01 Permalink

THE HAPPENING WORLD: Has the XENON1T Experiment Detected Dark Energy?

A SCANALYZER post on 2021-09-10 discussed the XENON1T experiment and its detection of the decay of Xenon-124 with a half life of 1.8×1022 years, the rarest physical phenomenon ever directly observed. Now, a paper in Physical Review D (full text [PDF]) examines whether the excess electron recoils observed by XENON1T could be due to “chameleon-screened dark energy” quanta produced in the Sun.

Wouldn't it be ironic if a massive detector built to observe dark matter particles ended up detecting dark energy?

Posted at 12:26 Permalink

CONTEXT: Cellular Automata Laboratory, the Music Video

Just like Peter Schickele's P. D. Q. Bach concerts, I couldn't resist slipping a little something of my own in. Cellular Automata Laboratory is a little-known and, in my opinion, underappreciated cornerstone of Fourmilab. In 1988 and 1989 Rudy Rucker and I developed the original Cellular Automata Laboratory for MS-DOS, using every dirty trick in the armamentarium of the whacked-out 80x86 assembly language programmer to wring acceptable performance out of the machines available to us and our audience, which amounted to IBM PC/AT and clones running an 80286 processor at 6 MHz. At one point, I hooked an oscilloscope up to an extension card to verify the inner loop of my evaluator and screen update code was driving the memory as hard as it could be driven, without waiting for the processor.

In 2017, impressed with the spectacular progress in browser-based applications implemented in JavaScript and the power of the canvas graphics facility, I decided to explore whether Cellular Automata Laboratory might be resurrected as a Web application. Well, it worked, and in June 2017 it went live—try it for yourself! (Here is a more detailed history of Cellular Automata Laboratory and the complete development log of the Web edition.)

One of the innovations in the Web version was “shows”—the ability to script self-running demonstrations, and this was used to create a series of YouTube videos illustrating various cellular automata rules implemented in it. These were, however, all silent movies. Now, Jason Higley has set the Cellular Automata Laboratory demonstrations to freely redistributable music, which dramatically improves the flow and watchability of the video. Enjoy!

Posted at 11:29 Permalink

CONTINUITY: Weekly Space Report: Starship and Starbase Developments, Inspiration4, Starlink Laser Satellite Links

Separately, Elon Musk appears to have confirmed that Starlink will be used to provide global coverage for satellites in Earth orbit using Ka band microwave or laser links to Starlink satellites. This could be a game changer for those operating low Earth orbit constellations, who now must rely on occasional passes over ground stations or costly geosynchronous relays.

Posted at 10:46 Permalink

Saturday, September 18, 2021

THE HAPPENING WORLD: U.S. Federal Aviation Administration Draft Programmatic Environmental Assessment for SpaceX Starship Super Heavy Project

Here is the main page, “SpaceX Starship Super Heavy Project at the Boca Chica Launch Site”, which has links to the full documents, all of which are PDF. The main text is (deep breath), “Draft Programmatic Environmental Assessment for SpaceX Starship/Super Heavy Program at the SpaceX Boca Chica Launch Site in Cameron County, Texas” [PDF], which is 143 pages long. There are seven separate appendices which provide additional technical details, including a 109 page “Endangered Species Act Section 7 Consultation” [PDF] in which you will learn of the potential consequences of humanity's escaping the Earth's gravity well on the Northern Aplomado Falcon, the Gulf Coast Jaguarundi, and Kemp's Ridley Sea Turtle.

Public comments are solicited and should be submitted by October 18th, 2020, and there will be two “virtual public hearings” (whatever that is) on October 6th and 7th with a presentation and opportunity for public oral comments.

It remains to be seen whether Elon Musk is heard muttering to himself, “…emigrated to the wrong country.”

Posted at 14:37 Permalink

THE HAPPENING WORLD: SpaceX: Inspiration4 Reentry and Splashdown

Splashdown off the coast of Florida is scheduled for 23:06 UTC on Saturday, 2021-09-18. Coverage of the return to Earth will presumably start some time before that.

In other monuments of space exploration, Inspiration4 mission commander Jared Isaacman placed the first Las Vegas sports bet from space on 2021-09-16.

Posted at 12:00 Permalink

CONTEXT: Extreme Ultraviolet Lithography for Semiconductor Manufacturing, Part 1 of 3

The latest generation of integrated circuits have device geometries far smaller than the wavelength of visible light. The shortest wavelength the human eye can perceive is around 380 nanometres, while feature sizes in production chips are as small as 7 nanometres, with the next generation expected to be 5 nanometres. To expose the circuitry on a silicon wafer requires illumination on the scale of the feature size, so visible light has become hopeless. Extreme ultraviolet (EUV), which occupies a band of the electromagnetic spectrum just below soft X-rays, provides a way to reach such geometries, with a wavelength of 13.5 nanometres used in semiconductor manufacturing today. But it isn't easy: almost all materials absorb EUV, so lenses cannot be used to focus it and all processing must be done in a vacuum. The best mirrors, which are themselves hideously difficult to manufacture nanoscale structures, reflect only around 70% of incident light, and EUV and the means used to generate it rapidly degrade materials. The process of taming EUV and applying it to mass manufacturing has taken over twenty years by a global collaboration of researchers, technologists, and industry. This video series traces the story of its development.

Posted at 11:15 Permalink

CONTINUITY: Apollo Spacecraft S Band Communication System, Part 1

The Apollo Unified S Band Communication System multiplexed voice, telemetry, computer data up- and down-links, ranging, and television onto a microwave channel sent to the ground by an 11.6 watt transmitter through the service module's high gain antenna. In this episode, original ground test transponder and amplifier units are opened and examined and the architecture of the communication system explained.

Posted at 10:55 Permalink

Friday, September 17, 2021

THE HAPPENING WORLD: SpaceX: Inspiration4 Live Update from the Crew in Space

The event is scheduled to start at 20:55 UTC on Saturday, 2021-09-17.

Posted at 18:48 Permalink

CONTEXT: Sir Clive Sinclair, 1940–2021, R.I.P.

Among the many amazing innovations of this prolific inventor, who dedicated most of his work to bringing high technology to everybody at a price they could afford, was the breakthrough 1974 Sinclair Scientific calculator, the first single chip scientific calculator, which offered, in addition to the four arithmetic operators, sine, cosine, tangent, arcsine, arccos, arctan, log, and exponentiation. Through cleverness and hackery which rose to epic levels of heroism, this was squeezed into a read-only memory which held just three hundred and twenty instructions. How did they do it? See Ken Shirriff's brilliant reverse engineering of the Sinclair Scientific design and programming. The calculator was sold in the U.S. in kit form for just US$99.95 and assembled for US$139.95, a fraction of the price of scientific calculators from Hewlett-Packard and Texas Instruments.

Clive Sinclair went on to design the ZX80 home computer, introduced in 1980 as a £79.95 kit or £99.95 assembled, which was an immediate hit. It, and its successors, were the introduction to computing for a generation of British and European programmers, and its successors were marketed in the U.S. by Timex Sinclair.

In his later years, Sinclair said that he did not use the Internet, as having “technical or mechanical things around me” distracted from the process of invention.

Posted at 13:45 Permalink

THE HAPPENING WORLD: Non-Fungible Tokens as Luxury Goods in the Metaverse

This is a long article, but well worth your time and attention. Although somewhere between 95% and 100% of the current mania for non-fungible tokens (NFTs) (NFT market value tripled in 2020 to more than US$250 million and exceeded US$2 billion in the first quarter of 2021) is almost certainly scams and a bubble fueled by unprecedented creation of central bank funny money, there may actually be the kernel of something real there which merits investigation.

Luxury goods have been a part of human civilisation almost since its inception, and in their modern incarnation, brands, are worth billions and fiercely defended by their owners. Simply affixing a brand name to something as generic as a t-shirt can multiply its market value by a large factor, with customers willing to pay a premium to identify themselves with the prestige of the brand and demonstrate their willingness and ability to waste money to display their own prestige. As human interaction moves increasingly from in-person contact with a small number of people in a locality to virtual venues on a global scale, is it not reasonable to expect this phenomenon to persist in the new medium and perhaps become even more prevalent as the size of the audience increases? Consider how much some value the Twitter “blue check mark” (which has no value and means nothing other than the approbation of the collectivist slavers who run that place), fear its revocation for bad-think, and hold their tongue rather than imperil it.

The article concludes:

Flexing is integral to the human experience. We don’t question the value of physical meatspace items used to project social standing. We understand and value fashion, paintings, jewelry etc. We all don costumes at work that illustrate which professional community we belong to. What is an investment banker without his Hermes tie or her pair of red-soled Louboutins? The costume is part of the self-worth.

Just because robots take all of our meatspace jobs doesn’t mean that humans stop being humans in the metaverse. Social signaling will take new forms powered by blockchain enabled NFT “worthless” objects. Those who recognise the similarities and are early to the creation of a new market for digital Flex goods will reap astronomical returns. Those content to pooh pooh this new worthless form of social signal can continue to walk down a street, into a shop, and purchase a $500 white t-shirt from some well-marketed fashion house. Choose your Flex Good appropriately.

Scalable Flexing is a tech person’s dream. The ability to appear wealthy and cool is not limited to physical proximity, but the entire addressable market of your avatar.

In the news, the Inspration4 private space mission is “carrying” an NFT into Earth orbit. At this writing, 13,520 have been sold.

Posted at 12:11 Permalink

CONTEXT: Sputnik 1—Satellite, Scare, and Space Race

Posted at 11:35 Permalink

CONTINUITY: KIC 8462852 (Boyajian's Star) Continues to Mystify

I'm not saying it's aliens…but what the heck is going on? The continued and possibly periodic dimming episodes and secular decline in brightness of of KIC 8462852, an otherwise unremarkable F-type main-sequence star located around 1470 light years from the Sun in the constellation of Cygnus, continues to bat away every proposed natural theory of origin. Might we be watching stellar lifting in progress?

Posted at 11:08 Permalink

Thursday, September 16, 2021

THE HAPPENING WORLD: A Bolt from the Blunderers

Posted at 15:55 Permalink

THE HAPPENING WORLD: U.S. Federal Reserve Flexible Consumer Price Index Remains in Record Territory

U.S. Federal Reserve flexible consumer price index, August 2021

Ever since December 1967, the U.S. Federal Reserve Bank of Atlanta has published a monthly report called the “Sticky-Price Consumer Price Index (CPI)”. The complete time series may be consulted at the St. Louis Federal Reserve's FRED site as data set COREFLEXCPIM159SFRBATL. This index is composed of a weighted basket of goods whose prices have, historically, changed relatively rapidly, and excludes the core items of food and energy. It has, over time, given a snapshot of “sticker price” inflation as perceived by the general populace.

Over its history, the index has mostly meandered in a random walk between 0 and 5 percent annual price change, with two large spikes in the vicinity of 10% in early 1975 and 1980–1981. That's before the index for April 2021 (reported around the middle of the following month, as always), which jumped in one month from 2.5% annualised in March to 8.2% for April. In May, it hit an all-time high since its inception in 1967 of 12%, then in June rocketed to another record of 16.7% and rose slightly to 16.76% in July. The August figures have just been published, and show a decline to 14.7%, which is still around 50% higher than at any time in the half century preceding 2021.

Now, monetary inflation doesn't act all at once or uniformly across an economy. It usually first causes rapid price appreciation in volatile financial markets which tends to feed on itself as a bubble mentality develops (check!), then some time later begins to show up in flexible prices such as tracked by the present index. Only later do “sticky” prices begin to budge, and finally the circle closes as workers demand pay increases to cope with the rising cost of living, which feeds back into cost of goods and accelerates price increases. All of this is generally accompanied by phenomena such as “labour shortages”, “supply chain disruptions”, “a tight housing market”, and other distractions cited by the perpetrators to shift blame from the actual cause, which is profligate money printing uncoupled from the supply of goods in the market.

In any case, here we have another of what what I call a “Year of the Jackpot” chart, showing something happening which has never before occurred during the lifetimes of a majority of living humans. It is not unreasonable to infer that such indicators might portend consequences which are equally outliers to conventional wisdom expectations.

Posted at 13:44 Permalink

TRACKING WITH CLOSEUPS: SpaceX Inspiration4 Launch Replay

This is a complete replay of the Inspiration4 orbital flight preparations and launch, four hours and forty minutes in length, covering the flight through orbital insertion and separation from the booster's second stage. If you want to start at the launch, skip forward to the 4:16:26 point, one minute before liftoff.

Here is Scott Manley's preview of the mission.

Posted at 13:07 Permalink

CONTEXT: The Strange Orbit of “Earth's Second Moon”

The asteroid 3753 Cruithne is in an Earth-crossing orbit (thus classified as an “Aten asteroid”) with an orbital period identical to that of Earth. Its elliptical orbit takes it as far as 1.51 astronomical units (AU) (the mean distance between the Earth and Sun) from the Sun and as close as 0.5145 AU. This means that its position traces out a closed path around the Earth and, in the Earth's reference frame, appears to orbit Earth in a D-shaped “kidney bean” orbit, although it is not gravitationally bound to the Earth and thus not a true satellite. Although subject to perturbations by other planets over the very long term, this orbit is believed to be stable for millions of years into the future.

Posted at 11:26 Permalink

TRACKING WITH CLOSEUPS: Impact Observed on Jupiter

The impact occurred during a transit of Jupiter's moon Io (visible to the left of Jupiter in the photo above, along with its shadow on Jupiter's clouds), a photogenic event which a number of amateur astronomers were imaging at the time.

Posted at 11:06 Permalink

Wednesday, September 15, 2021

TRACKING WITH CLOSEUPS: What Can You Get for £0.12 in Today’s Britain?

Posted at 12:17 Permalink

CONTINUITY: The UAC TurboTrain—America's Failed Attempt at High-Speed Rail

I do not use “America” as a sloppy synonym for the United States: the trains were manufactured and used both in Canada and the U.S. Here is more on the UAC TurboTrain.

Posted at 11:36 Permalink

CONTEXT: Stop Digging—You're Headed for the Indian Ocean!

Posted at 11:10 Permalink

THE HAPPENING WORLD: SpaceX Inspiration4 Launch

The Inspiration4 launch, the first completely privately funded and crewed orbital space mission, is scheduled for 2021-09-16 at 00:02 UTC, which is in the evening hours of Wednesday the 15th of September in Western Hemisphere time zones. As this is not a rendezvous with the space station, there is a five hour launch window should delays occur. At this writing, weather is predicted to be 80% favourable at the start the launch window. Launch opportunities are available on subsequent days in case the launch is scrubbed on the first attempt. Expected mission duration is around three days, with splashdown off the Florida coast.

Everyday Astronaut has complete details of the planned mission in the Inspiration4 Prelaunch Preview.

This will be the first crewed orbital launch not bound for the International Space Station since Space Shuttle STS-125 in May 2009, which performed the final repair mission to the Hubble Space Telescope. The Crew Dragon spacecraft, C207-2, was previously flown on the NASA Crew-1 mission in November 2020, and Falcon 9 booster B1062 is making its third flight. The Crew Dragon has been modified by removing the docking adaptor, replacing it with a bubble cupola which will provide panoramic views of the Earth and sky.

Here is a pre-flight question and answer session with the crew the day before launch.

Posted at 10:34 Permalink

Tuesday, September 14, 2021

CONTINUITY: Nike-Hercules—When U.S. Cities were Ringed with Nuclear-Tipped Missiles

When I was a kid, my parents took me on a week-end tour of a local Nike-Ajax site, probably in 1958 or 1959. They showed you everything, except inside the circular berm where they did hazardous propellant maintenance operations. (Nike-Ajax used toxic hypergolic liquid propellants in its second stage.) Afterward, the site was converted to the nuclear-tipped Nike-Hercules, and no tours were offered.

At the peak, there were 265 Nike-Ajax sites in the U.S. The longer range Nike-Hercules covered a larger area, and was deployed in only 130 locations, with the excess Nike-Ajax sites decommissioned.

Posted at 12:49 Permalink

CONTINUITY: Tour of the International Space Station Kibō Module

This tour, presented in 360° immersive video (hold down your mouse button within the image and move the pointer to pan and tilt your viewpoint), is conducted by European Space Agency astronaut Thomas Pesquet. The audio is in French, with English subtitles. The Kibō (きぼう) or Japanese Experiment Module (JEM) was launched to the International Space Station by three space shuttle missions in 2008 and 2009, and is the largest single module of the space station. It includes a pressurised laboratory section and an external pallet with an airlock for moving payloads back and forth to the laboratory, with a robot arm to manipulate them. There is also an “attic”, which provides much-needed storage space on the crowded station.

Posted at 12:04 Permalink

CONTINUITY: Vacuum Tube Computer Part 17: Arithmetic/Logic Unit

Finally, all of the previously design, built, and tested pieces of the computer begin to come together at its heart: the unit which performs the arithmetic or logic operation designated by an instruction. This is simpler than you might imagine, as it consists mostly of selecting a result among multiple logic inputs that compute the results of the various functions, all of which have been previously constructed.

Posted at 11:32 Permalink

CONTINUITY: On the Road with Tesla “Full Self Driving” Beta 10

Here is another report, driving in San Francisco and deliberately putting the car into difficult situations.

Two things amaze me about this deployment of “full self driving” on the litigious streets of Safetyland. First, that paying customers are so forgiving of a product which, after ten releases, still does not remotely do what it is claimed to—drive autonomously without a vigilant human driver ready to take over an in instant when it “disengages” or is about to turn into oncoming traffic. Second, that Tesla, a public company with PricewaterhouseCoopers as its auditors, is not required to qualify its financial statements with risk factors due to liability from mass deployment of a flawed product with such potential risk to life, limb, and third-party property damage, and that its directors seem fine with the situation. (Here are the declared risk factors from Tesla's most recent Form 10-K filing with the U.S. Securities and Exchange Commission.)

Posted at 11:00 Permalink

TRACKING WITH CLOSEUPS: SpaceX Starlink Group 2-1 Mission

I have cued the video to start one minute before launch: scroll back if you wish to watch from earlier in the countdown. This was the tenth successful launch and landing for Falcon 9 first stage booster B1049, the oldest booster currently in service, having made its first flight on 2018-09-10. This booster joins B1051, which achieved the milestone of ten flights on 2021-05-09, meeting the original design goal of ten flights per booster. Elon Musk has said that SpaceX will continue to inspect and re-fly boosters, building experience in long-term re-use. I suspect that “fleet leaders” with the greatest number of flights will be reserved for in-house Starlink missions, where a loss due to unanticipated aging issues would not impact an external customer.

Posted at 10:32 Permalink

Monday, September 13, 2021

THE HAPPENING WORLD: SpaceX Starlink Group 2-1 Launch

Launch is scheduled for 03:55 UTC on 2021-09-14 (note that this is in the evening of the 13th in Western Hemisphere time zones) from Vandenberg Space Force Base in California. These Starlink satellites are equipped with laser inter-satellite links, which reduces the need for ground stations in remote areas. If successful, this will be the 100th consecutive Falcon 9 mission, the 125th Falcon 9 launch, and the 70th re-flight of a first stage booster. Both the first stage and both of the fairing halves have previously flown.

Posted at 19:55 Permalink

THE HAPPENING WORLD: Astrophysical Journal Publishes “If Loud Aliens Explain Human Earliness, Quiet Aliens Are Also Rare”

Read the full paper on ArXiV.

Posted at 14:09 Permalink

TRACKING WITH CLOSEUPS: From Egg to Monarch Butterfly

Here is the pupation process in real time,

And this is emergence of the mature butterfly from the pupa.

At the end of this process, the wings are soft and will take a couple of hours to harden before taking flight.

Posted at 12:58 Permalink

CONTINUITY: “SX-70” by Charles and Ray Eames

In 1972, instant photography reached an apogee with the Polaroid SX-70, a camera which was simultaneously foldable, single-lens reflex, automatic exposure, and instant, with the pictures developing outside the camera in broad daylight and requiring no messy coating or throw-away parts. Film was sold in cartridges of ten pictures, each of which included a disposable battery that powered the electronics and motorised machinery of the camera. Focus was manual on the original model; later models added ultrasonic sonar automatic focusing.

This film was produced for Polaroid by the Eames Office and shown at the shareholders' meeting when the camera was introduced and later used by the sales organisation.

Posted at 11:53 Permalink

TRACKING WITH CLOSEUPS: What Really Happened to the Arecibo Telescope?

Posted at 10:35 Permalink

Sunday, September 12, 2021

CONTEXT: Revealed! “Algorithmic Abstraction and the Racial Neoliberal Rhetorics of 23andMe”

Here is the article, “Algorithmic Abstraction and the Racial Neoliberal Rhetorics of 23andMe”, published in the journal Rhetoric Review, vol. 40, no. 3, September 2021. The link, of course, only gives the abstract, which is as follows.

Western mathematics functions as a technology of violence when it enlists computational algorithms to underwrite racial neoliberalism. Theorizing algorithmic abstraction as a racial neoliberal technique, this article dramatizes the concept’s methodological affordances through a case study of 23andMe, which deploys algorithmic abstraction to affectively secure and sell Whiteness.

If you want to read the full text (and why wouldn't you, since who knows more about algorithmic abstraction and genetic sequencing and analysis than three English professors?), it'll cost you US$45 to download a PDF, or (bargain!), just US$159 for the whole journal issue.

Actually, I wonder if the postmodern title of the article is how you say, “I'll bet these DNA testing outfits eventually end up ratting out their customers' genomes to the Man” in Woke.

Posted at 13:27 Permalink

CONTINUITY: Jet-Powered Parasitic Fighter: McDonnell XF-85 Goblin

Here is more about the XF-85 Goblin. The task of re-attaching to a trapeze lowered by a bomber in the turbulent environment of its slipstream proved too demanding for even the very best test pilots. By the time the difficulty became apparent, progress in in-flight refuelling had rendered the concept of parasitic aircraft carried by larger planes obsolete.

Posted at 12:41 Permalink

TRACKING WITH CLOSEUPS: IBM Patent Application for “Telum” Mainframe CPU Cache

The unusual “cache virtual memory” architecture of the next generation “Telum” processors for IBM's Z-Series mainframes was discussed here on 2021-09-03. IBM have filed a U.S. patent application, US 2021/0026783 A1 [PDF], on 2021-01-28 which describes the “black magic” behind how it maintains consistency and low latency with multiple levels of processors sharing cache and “borrowing” storage from one another.

Are my eyes deceiving me, or is the text in Figures 7, 11, and 12 actually Comic Sans?

Posted at 11:48 Permalink

THE HAPPENING WORLD: Weekly Space Report: Starship Thermal Protection, Super Heavy Booster Thrust, and Inspiration4 Launch

Posted at 11:06 Permalink

Saturday, September 11, 2021

CONTINUITY: Railroad Car Ferry

Posted at 13:39 Permalink

TRACKING WITH CLOSEUPS: Narrowing the Search for Planet Nine


The existence of a giant planet beyond Neptune — referred to as Planet Nine (P9) — has been inferred from the clustering of longitude of perihelion and pole position of distant eccentric Kuiper belt objects (KBOs). After updating calculations of observational biases, we find that the clustering remains significant at the 99.6% confidence level. We thus use these observations to determine orbital elements of P9. A suite of numerical simulations shows that the orbital distribution of the distant KBOs is strongly influenced by the mass and orbital elements of P9 and thus can be used to infer these parameters. Combining the biases with these numerical simulations, we calculate likelihood values for discrete set of P9 parameters, which we then use as input into a Gaussian Process emulator that allows a likelihood computation for arbitrary values of all parameters. We use this emulator in a Markov Chain Monte Carlo analysis to estimate parameters of P9. We find a P9 mass of 6.2[+2.2−1.3] Earth masses, semimajor axis of 380[+140−80] AU, inclination of 16±5∘ and perihelion of 300[+85−60] AU. Using samples of the orbital elements and estimates of the radius and albedo of such a planet, we calculate the probability distribution function of the on-sky position of Planet Nine and of its brightness. For many reasonable assumptions, Planet Nine is closer and brighter than initially expected, though the probability distribution includes a long tail to larger distances, and uncertainties in the radius and albedo of Planet Nine could yield fainter objects.

Posted at 12:54 Permalink

THE HAPPENING WORLD: Tour of the Chinese Space Station Tianhe Core Module

Dialogue is in Chinese, with scrolling English subtitles.

Posted at 12:14 Permalink

CONTEXT: Thallium—Colour, Compounds, and Murder

Posted at 11:12 Permalink

Friday, September 10, 2021

CONTINUITY: Selenium Rectifiers—When They Blow Up, It’s Like a Rectal Fire

You'll find these in all kinds of electrical and electronic gear dating from the 1930s through the 1960s. They were the first (kind of) practical solid state rectifier, but had limited reverse voltage capability and required a stack of individual junctions for mains and higher voltage applications. They had a forward voltage drop of around one volt, which would increase as the unit aged. In high voltage and current applications, this could eventually lead to thermal runaway as heat dissipation and resistance increased, ending with a bang and release of hideously malodorous and toxic smoke. At least, when this happened, there was no question about what was wrong.

Posted at 14:11 Permalink

CONTINUITY: Interstellar Visitors in the Oort Cloud

Objects in the Oort cloud orbit the Sun very slowly: some less than 150 metres per second. This means it takes very little delta-v to cancel enough velocity to cause them to plunge into the inner solar system, where we observe them as comets. Interstellar comets, however, pass through the Oort cloud with velocities typical among nearby stars of tens of kilometres per second and continue unperturbed along their paths. This may have the consequence that in the outer Oort cloud interstellar comets outnumber those gravitationally bound to the Sun by a substantial margin.

Posted at 13:28 Permalink

CONTEXT: Ailerons Connected Backwards! The Wild Flight of Air Astana 1388

Here is more about the Air Astana flight 1388 incident.

Posted at 12:13 Permalink

THE HAPPENING WORLD: Radioactive Decay of Xenon-124 Observed: Half-Life 1.8×1022 Years

Xenon-124 decays to stable tellurium-124 by double electron capture with a half life of 1.8×1022 years, which is around a trillion times the present age of the universe. Its observation by the XENON1T detector is the rarest physical phenomenon ever directly detected. This handily exceeds the previous record set in 2003 by the observation of decay of bismuth-209, half life 1.9×1019 years, about which I wrote in “Barely Radioactive Elements”. This isn't, however, the longest-lived known isotope: tellurium-128, with a double beta decay half life of 2.2×1024 years, which is more than 160 trillion times the age of the universe.

Posted at 11:35 Permalink

Thursday, September 9, 2021

THE HAPPENING WORLD: The Metaverse—Second Coming for Second Life?

Posted at 13:06 Permalink

TRACKING WITH CLOSEUPS: Were the Boskops, Prehistoric Hominids, More Intelligent Than Modern Humans?

And if they were, and evolution selects for intelligence, what happened to them? Maybe they invented socialism, let technological development stagnate and be regulated out of existence, then ceased to breed when the cost of forming families and raising children became too high for the young.

Posted at 12:47 Permalink

CONTEXT: Moonfall—Do It Yourself Guide

There is a teaser trailer out for a movie scheduled for release in February 2022, Moonfall, which looks to be a particularly cheesy and absurd techno-disaster-thriller flick, even by the standards of the genre. See for yourself.

The premise is that the Moon has, for some reason, fallen out of its orbit and is closely approaching the Earth—in 2022. (I guess it really takes something to beat 2020 and 2021.) Anyway, as opposed to tidal disruption of the Moon when it crosses the Roche limit (which, for the Earth, is 6378 km), ocean tides scrubbing clean all the continents, etc., what seems to happen involves crashing cars, explosions, and for some screwball reason, the NASA space shuttle coming back from museums to fly again. How bad can it be? Well, the credits include Donald Sutherland.

Just how did the Moon lose enough orbital velocity to come close to the Earth? I'm not saying it's aliens, but from the trailer, that's the way to bet. And why would aliens expend enough energy to de-orbit the Moon to wreak havoc on the Earth rather than the more economical approach I used in Trek's End? I guess we'll have to wait and see which, for me, means until it comes around on Netflix.

Here, Scott Manley does the math on bringing the Moon down to Earth, and simulates the event in Universe Sandbox. For aspiring cosmic supervillains, he explains how, if you're patient, you can do it with half the delta-v by using a bi-elliptic transfer.

Posted at 12:20 Permalink

CONTINUITY: Hewlett-Packard 150A Oscilloscope Restoration: Part 3

With basic functionality restored, the focus turns to the inoperable second channel, a mystery thermistor, dodgy tubes, leaky capacitors, calibration, and the eternal confusion of RMS and peak-to-peak AC voltages. The behaviour of vacuum tube direct coupled and balanced amplifiers can be subtle, and even the slightest change can be puzzling.

Posted at 11:14 Permalink

Wednesday, September 8, 2021

THE HAPPENING WORLD: Launch Date Set for James Webb Space Telescope

After twenty-five years of development and an order of magnitude cost overrun to US$ 10 billion, they're going to “push the button” and see what happens.

Posted at 14:03 Permalink

CONTEXT: Alvy Ray Smith, Computer Graphics Pioneer, and A Biography of the Pixel

Alvy's book, A Biography of the Pixel, was published in August, 2021.

Posted at 12:42 Permalink


Posted at 11:40 Permalink

CONTINUITY: Gun Launch to Earth Orbit

The 1991 paper, “A revolution in access to space through spinoffs of SDI technology” is, thirty years later, behind an IEEE paywall because, of course, it's only fair that the taxpayers who paid for this research should have to fork over US$33 to a private organisation in order to read it. Fortunately, Sci-Hub rides to the rescue with the full text.

Posted at 11:10 Permalink

CONTEXT: The Area of a Super-Circle: Elliptic Integrals and Lemniscate Biscuits

Posted at 10:42 Permalink

Tuesday, September 7, 2021

CONTINUITY: The Curious Behaviour of Bullets in First-Person Shooter Games

One of the reasons many games use the “hitscan” model, where bullet flight is instantaneous, is that it is very easy to implement and fast to evaluate using “ray casting” from the player's viewpoint in the direction of look (and aim, which is the same). You just project a vector along that direction and look for the first intersection with an object in the scene, and there's your point of impact. Then you just render the shot along that vector with suitable sound and light effects. Modelling the flight of a projectile with physics is a lot more difficult, and requires taking into account motion of objects in the scene while the projectile is in flight.

If you think this is weird, there's been a flaw in Second Life since early 2020 where, in some regions of the grid, when you shoot a projectile, it may just hang in the air in front of the launcher for two long seconds, then take off in the direction of the target. I wasted a huge amount of time in development of my Anvil Tosser trying to work around this and finally concluded it can only be remedied by fixing the fundamental problem in the simulator. Here is some of my research into this problem, and some more.

Posted at 11:56 Permalink

THE HAPPENING WORLD: Anti-Speech Weapons and the “Suck Button”

Posted at 11:40 Permalink

CONTEXT: How Do We Know if a Meteorite Came From Mars?

Posted at 11:11 Permalink

TRACKING WITH CLOSEUPS: Cutting a Torus with Three Planes

Posted at 10:29 Permalink

Monday, September 6, 2021

CONTINUITY: The Relaxed Wife—“Who Needs Tranquillity? I'm Hopped Up on Goofballs!”

From 1957, Pfizer promotes “ataraxic medicine”.

It makes those who fear they're about to quit feel like they're ready to begin, bidding their darkened spirits goodbye, for the calming peace of a cloudless sky. [8:20]

What could possibly go wrong?

Posted at 13:05 Permalink

CONTINUITY: A History of Bitcoin Transaction Dust and Spam Storms

Posted at 12:45 Permalink

CONTEXT: International Space Station Transits Mars

Posted at 12:34 Permalink

THE HAPPENING WORLD: 110 Year Old, US$78 Billion Company Spins Off 90,000 Employee Subsidiary, Nobody To Know What It Is

And then there's the name, “Kyndryl”, about which CNN Business reported, “IBM spinoff joins a long list of questionable corporate names”, which begins:

There's a new member in the pantheon of the worst-named companies in history. Introducing "Kyndryl."

That is the actual name of the IT services unit that IBM is spinning off from its core business.

Soon, the 90,000 employees affected by the change will no longer say they work for "IBM" — perhaps one of the more classic, unambiguous corporate names ever — but instead for "Kyndryl," a portmanteau whose meaning and pronunciation aren't immediately clear.

IBM says the "kyn" part of the name is derived from is the word "kinship," and "dryl" comes from tendril, which it said should bring "to mind new growth and the idea that ... the business is always working toward advancing human progress."

Somehow, explaining it just makes it worse. We can deduce that the pronunciation, based on IBM's stated logic, is "KIN-drill," but the seemingly arbitrary use of Ys as vowels opens the door to long-I interpretation: KINE-drile?

Googling the term doesn't find many alternate uses, although there is a scary-looking "World of Warcraft" character that goes by that name.

They've come a long way since “Ever Onward IBM” (lyrics).

Posted at 12:13 Permalink

TRACKING WITH CLOSEUPS: Simulating Biological Neurons with Artificial Neural Networks

Posted at 12:03 Permalink

Sunday, September 5, 2021

THE HAPPENING WORLD: Mars Helicopter Ingenuity Completes 13th Flight

Ingenuity has now been operating on Mars for 141 sols (Martian days), far beyond its planned 30 day technology demonstration mission. It is now being used to scout destinations and routes for the Perseverance rover, which deployed it on 2021-04-03. Here is a pre-flight summary of the plan for flight 13.

Posted at 13:30 Permalink

TRACKING WITH CLOSEUPS: Single Event Upsets—Computer Crashes from Deep Space

Note that while error correction code (ECC) memory can dramatically reduce the vulnerability of computer systems to errors induced by cosmic rays or other exogenous sources (memory arrays are very dense and have few electrons per storage cell, and thus present both a large and soft target), the logic circuits within processors and other electronics remain at risk and, except for special-purpose and very expensive “radiation hardened” or multiple redundant hardware designed for aerospace applications, are not protected against upsets.

Single event upsets due to cosmic rays do not damage electronics: they just cause transient errors where the computer does something it isn't supposed to. This makes it extremely difficult to diagnose the source of the problem, and when something apparently inexplicable happens due to poorly designed and incompetently implemented software (for example, that intermittently operating system famed for its “blue screen of death”), its sloppy perpetrators sometimes blame it instead on “a cosmic ray”. It does happen, but usually it's crappy code.

Posted at 12:45 Permalink

CONTINUITY: Colour-Motion Optical Illusion

Posted at 12:21 Permalink

THE HAPPENING WORLD: Weekly Space Report: Starbase Infrastructure, Cargo to ISS, Smallsat Stumbles

Posted at 11:33 Permalink

Saturday, September 4, 2021

CONTEXT: Brian Keating on Life in the Universe, UFOs, and GalileAIo

Posted at 12:23 Permalink

CONTINUITY: Tour of the International Space Station's New Nauka Module

The tour is guided by European Space Agency astronaut Thomas Pesquet. The audio is in French, with English subtitles. The module, called Наука (Nauka), which means “Science” in Russian, is also known as the Multipurpose Laboratory Module (MLM) and is docked to the nadir (Earth-facing) port of the Russian segment of the space station.

Posted at 11:53 Permalink

TRACKING WITH CLOSEUPS: Why Are Scorpions Fluorescent?

Posted at 11:17 Permalink

CONTEXT: Reaver Destroys Firefly

Posted at 10:53 Permalink

Friday, September 3, 2021

THE HAPPENING WORLD: IBM Z-Series “Telum” Processor—Virtual Memory for CPU Cache?

Here is an IBM promotional video about the chip.

In the following video, Dr Ian Cutress explains the Telum architecture and what it might mean for future consumer market CPU designs.

Posted at 13:50 Permalink

CONTEXT: Age of Stupid, Part MMXCCLI

This is “selling” as a non-fungible token (NFT) for ETH 100, which at the current market price for Ether (the cryptocurrency of the Ethereum blockchain system) is valued at US$ 396,098. An “auction” is underway at a site called “PartyBid” which has, at this moment, commitments of ETH 54.96 (US$ 217,699) toward “purchasing” this work of “art”.

Posted at 13:14 Permalink

CONTINUITY: “The Big Switch”—IBM Computer Message Switching in 1963

Posted at 12:54 Permalink

THE HAPPENING WORLD: Dead Internet Theory

I asked GPT-J-6B about this. Here is what it said.

The internet is dead. It is all bots.

Bots are the only reason that anybody on the planet today cares what you have to say. Even I don't. If you haven't noticed that most of your blog/news posts go totally ignored, either I'm not aware of it or you are completely inept at writing. You're not the only one who can get it wrong, there are hundreds of other bloggers who do it too. It's just something to be aware of.

To make sure that you don't get lost in that sea of ignored posts and spam, I will now tell you what is going on. Spamming through blog networks, like the one I am on, is known as "blog bombing". We, who blog for free, are always the ones who are caught up in the spam bots. It's something that just has to be accepted.

Posted at 12:39 Permalink

TRACKING WITH CLOSEUPS: Ridges on Coins, Neutron Star Collisions, and Isaac Newton

Posted at 12:28 Permalink

THE HAPPENING WORLD: Firefly Aerospace Alpha Experiences “Anomaly” in Flight

“Anomaly” is how they say “KABOOM!” in Safetyland.

The following video from NASASpaceflight (which has nothing to do with the U.S. space agency) is taken from a distance and doesn't show the liftoff (which was normal) very well, but clearly shows, at the 2:24 point, when the rocket went all Kerbal and started tumbling end over end before being blown up (or, in Safetyland patois, “flight termination”) by range safety. “Jeb—turn on SAS!

In the coverage by Everyday Astronaut below, which I've cued to start one minute before launch, it appears the problems started before the loss of control. At the 1:59:42 mark, an odd plume appears at the left of the rocket camera image which wasn't visible previously and doesn't look like a regular exhaust expansion effect. At 2:00:07 there is a call of “Not yet supersonic” at a time which was supposed to be after passing max Q and Mach 1. The supersonic call does not occur until 2:00:36, much later than expected. Then, at 2:00:47 everything goes pear shaped.

Posted at 11:55 Permalink

Thursday, September 2, 2021

THE HAPPENING WORLD: Firefly Aerospace Alpha FLTA001 “DREAM” Launch

The launch of Firefly's first Alpha small satellite launcher is scheduled for a four hour launch window between 01:00 and 05:00 UTC on Friday, 2021-09-03. The launch will take place from Vandenberg Air Force Base, California, Space Launch Complex 2 (SLC-2). Weather is forecast as 100% favourable for launch. This is the first flight for Firefly and its rocket, and will be only the second launch from Vandenberg of any rocket in 2021. If successful, Alpha will place several small satellites in a 300 km orbit with 138° inclination. Here is a preview of the mission. Read more details about the Firefly Alpha.

Everyday Astronaut (Tim Dodd) will be livestreaming the launch attempt at the following channel, with the stream starting one hour before the scheduled launch time (which may be any time within the launch window).

The following video shows a static test firing of this rocket which was conducted on 2021-08-18. The first stage Reaver 1 (heh!) engines use a combustion tap-off cycle, which makes them challenging to start: you'll see a very prominent green flash of the TEA-TEB hypergolic starter fluid used to start combustion and ramp up to sufficient chamber pressure to allow the tap-off to drive the turbopumps.

If you look closely at this video, you may spot an Autodesk logo on the first stage. Autodesk products were used by Firefly in the design of the vehicle, as described by this page and embedded video.

Posted at 18:56 Permalink

TRACKING WITH CLOSEUPS: Universal Equation for the Shape of Birds' Eggs

The paper, “Egg and math: introducing a universal formula for egg shape”, is behind a paywall, with the Wiley journal charging US$ 16 to look at it online for 48 hours up to US$ 49 to download a PDF. Nobody seems to have uploaded it so far to SciHub, so we'll have to wait until some public-spirited roadrunner with institutional access liberates it. There is, however “supplementary material” for the paper, in gnarly Microsoft Word format, which can be downloaded from the abstract page and opens in LibreOffice. This document provides sufficient information to figure out what they're doing and how to apply the model, although you'll have engage in a bit of reverse engineering.

Posted at 14:54 Permalink

CONTEXT: Litigation vs. Innovation: SpaceX Responds to Amazon Anti-Starlink Filing

With Blue Origin falling far behind SpaceX and failing to deliver the engines it contracted to furnish for United Launch Alliance's next generation Vulcan rocket, and Amazon's Kuiper satellite Internet service yet to launch its first satellite while SpaceX's Starlink is approaching full operational status, Jeff Bezos seems to be adopting a strategy of suing his way to the stars, with litigation underway against NASA to block their selection of SpaceX for the human lunar lander and regulatory filings against SpaceX's plans to expand their Starlink constellation.

SpaceX just responded to the Amazon anti-Starlink filing with the U.S. Federal Communications Commission with this response [PDF], which begins with:

This letter is in response to the latest familiar tactics by Kuiper Systems LLC (“Amazon”) to delay a competitor, this time by claiming that Space Exploration Holdings, LLC (“SpaceX”) provided the Commission too much information about its next-generation constellation. Amazon’s recent missive is unfortunately only the latest in its continuing efforts to slow down competition, while neglecting to resolve the Commission’s concerns about Amazon’s own non-geostationary orbit (“NGSO”) satellite system. The Commission should see through these efforts and quickly put SpaceX’s application out for public comment where any issues can be fully vetted.

and concludes:

SpaceX has submitted complete information on its proposed next-generation constellation, satisfying every information requirement in the Commission’s rules. Amazon would clearly prefer to use procedural maneuvers to delay consideration of that application rather than allow it to proceed to consideration on the merits. As Amazon’s former Chief Executive has said in the past, procedural maneuvers—like the ones Amazon now deploys—have “become the bigger bottleneck than the technology.” The Commission should recognize this gambit for the obstructionist tactic that it is, reject Amazon’s request, and quickly put the amendment out for public comment.

Posted at 14:31 Permalink

THE HAPPENING WORLD: Intel's Xeon “Sapphire Rapids” Multi-Tile Processors

Posted at 13:55 Permalink

CONTEXT: Virgin Galactic's First Passenger Mission Flew off Course

“…a yellow light should 'scare the sh-- out of you, because when it turns red it's gonna be too late.”

Posted at 13:05 Permalink

CONTINUITY: Apollo Command Module: Excellent Spacecraft—Terrible Boat

Posted at 12:11 Permalink

Wednesday, September 1, 2021

CONTINUITY: HP 9825 Repair Part 11—Debugging the Keyboard, Display, and Printer Board

The repairs of earlier episodes got the Hewlett-Packard 9825 laboratory computer working, but only with a keyboard, display, and printer module borrowed from a working 9825. Now the focus moves on to repairing the module from the unit fried when its power supply blew up. This is a worrisome task, since this module's circuit board includes a custom Hewlett-Packard application-specific integrated circuit (ASIC) which, all these years later, might as well be made of gold-pressed unobtainium.

Posted at 15:15 Permalink

THE HAPPENING WORLD: Finally—Computer Engineering for Babies

Posted at 14:42 Permalink

TRACKING WITH CLOSEUPS: Using Galactic Supernovæ as SETI Signal Beacons

The research paper is “Search for Galactic Civilizations Using Historical Supernovae”.


We study an interstellar signaling scheme which was originally proposed by Seto (2019) and efficiently links intentional transmitters to ETI searchers through a conspicuous astronomical burst, without prior communication. Based on the geometrical and game theoretic viewpoints, the scheme can be refined so that intentional signals can be sent and received after observing a reference burst, in contrast to the original proposal (before observing a burst). Given this inverted temporal structure, Galactic supernovae recorded in the past 2000 years can be regarded as interesting guideposts for an ETI search. While the best use period of SN 393 has presumably passed ∼100 years ago, some of the historical supernovae might allow us to compactify the ETI survey regions down to less than one percent of 4π, around two rings in the sky.

Posted at 13:52 Permalink

CONTEXT: Giant Viruses and Their Predators

Posted at 13:09 Permalink

CONTINUITY: World Energy Production from 1860 to 2019

Posted at 12:53 Permalink