Chai Tea

1984

George Orwell

A limerick:

Dinosaur claws on show for our Open Day at National Museum Cardiff last Saturday. Can you tell which is Velociraptor?

Ottoman Empire and Edo-era Japan. You probably never thought about them together before, right? Turns out the Ottomans knew about Japan since at least the late 1600s, because the Ottoman scholar Katip Çelebi included Japan in his atlas “Displaying the World.”

He didn’t quite get the shape of the islands, or their number, or their names…but hey, he tried!

Smuggling salt is Slovenian culture!

Be proud of smuggling salt, people! We certainly are!

Isetan Departmental Store opening poster (1933).

Molecule of the Day - DDT

Dichlorodiphenyltrichloroethane (C14H9Cl5), more commonly known as DDT, is a colourless, tasteless solid under room conditions. It was used as an insecticide during the 1940s-1970s, and gained notoriety after Rachel Carson’s 1962 book, Silent Spring, which highlighted the health and environmental effects of DDT.

DDT acts by binding to voltage-gated sodium ion channels of neurons (as seen on the left of the diagram below), causing these channels to be permanently open instead of opening only upon the arrival of an action potential. Consequently, there is a continuous influx of Na+ ions into the neuron, which triggers a series of rapid action potentials and hence neuronal impulses. This leads to rapid muscle contractions, spasms, and death.

While this effect does not occur in humans and other non-insects, it is still moderately toxic, and as been shown to be an endocrine disruptor. Therefore, chronic exposure to it can lead to tumour formation, developmental problems, and birth defects. DDT is also considered to be a possible carcinogen.

Due to the hydrophobicity of DDT, it tends to accumulate in the lipids of living organisms rather than in the environment. This results in biomagnification, in which its concentration increases upon going up the food chain, as each organism of a rung of the chain consumes multiple prey. Consequently, the usage of DDT affected the populations of many birds of prey, such as the bald eagle.

In 1962, Rachel Carson published the book Silent Spring, which highlighted the negative effects of the usage of DDT and other pesticides on the environment and biodiversity. This book was revolutionary; it sparked a heated debate on pesticides and contributed to the 1972 US ban on DDT. The world followed suit; most countries around the world now prohibit the use of DDT, except for limited disease vector control purposes, such as for malaria.

DDT is synthesised by the condensation of a molecule of chloral and 2 molecules of chlorobenzene via an electrophilic substitution reaction, producing water as a by-product.

Happy Birthday, @smokey-bear (August 9th)!

Everybody loves Smokey the Bear and truthfully what’s not to love?  His message of conservation and environmental concern is even more relevant today than it was in 1944 when the campaign was created.  In 1952 the Smokey the Bear song was written by Steve Nelson and Jack Rollins and became a grade school standard.  Feel free to sing along: here are the lyrics from Living, Learning, Loving West Virginia from the Conservation Commission of West Virginia, 1958.  Have fun and remember “Only you can prevent forest fires.”

The code that took America's Apollo 11  to the moon in the 1960's has been published

When programmers at the MIT Instrumentation Laboratory set out to develop the flight software for the Apollo 11 space program in the mid-1960s, the necessary technology did not exist. They had to invent it.

They came up with a new way to store computer programs, called “rope memory,” and created a special version of the assembly programming language. Assembly itself is obscure to many of today’s programmers—it’s very difficult to read, intended to be easily understood by computers, not humans. For the Apollo Guidance Computer (AGC), MIT programmers wrote thousands of lines of that esoteric code.

Here’s a very 1960s data visualization of just how much code they wrote—this is Margaret Hamilton, director of software engineering for the project, standing next to a stack of paper containing the software:

The AGC code has been available to the public for quite a while–it was first uploaded by tech researcher Ron Burkey in 2003, after he’d transcribed it from scanned images of the original hardcopies MIT had put online. That is, he manually typed out each line, one by one.

“It was scanned by an airplane pilot named Gary Neff in Colorado,” Burkey said in an email. “MIT got hold of the scans and put them online in the form of page images, which unfortunately had been mutilated in the process to the point of being unreadable in places.” Burkey reconstructed the unreadable parts, he said, using his engineering skills to fill in the blanks.

  “Quite a bit later, I managed to get some replacement scans from Gary Neff for the unreadable parts and fortunately found out that the parts I filled in were 100% correct!” he said.

As enormous and successful as Burkey’s project has been, however, the code itself remained somewhat obscure to many of today’s software developers. That was until last Thursday (July 7), when former NASA intern Chris Garry uploaded the software in its entirety to GitHub, the code-sharing site where millions of programmers hang out these days.

Within hours, coders began dissecting the software, particularly looking at the code comments the AGC’s original programmers had written. In programming, comments are plain-English descriptions of what task is being performed at a given point. But as the always-sharp joke detectives in Reddit’s r/ProgrammerHumor section found, many of the comments in the AGC code go beyond boring explanations of the software itself. They’re full of light-hearted jokes and messages, and very 1960s references.

One of the source code files, for example, is called BURN_BABY_BURN--MASTER_IGNITION_ROUTINE, and the opening comments explain why:

About 900 lines into that subroutine, a reader can see the playfulness of the original programming team come through, in the first and last comments in this block of code:

In the file called LUNAR_LANDING_GUIDANCE_EQUATIONS.s, it appears that two lines of code were  meant to be temporary ended up being permanent, against the hopes of one programmer:

In the same file, there’s also code that appears to instruct an astronaut to “crank the silly thing around.”

“That code is all about positioning the antenna for the LR (landing radar),” Burkey explained. “I presume that it’s displaying a code to warn the astronaut to reposition it.”

And in the PINBALL_GAME_BUTTONS_AND_LIGHTS.s file, which is described as “the keyboard and display system program … exchanged between the AGC and the computer operator,” there’s a peculiar Shakespeare quote:

This is likely a reference to the AGC programming language itself, as one Reddit user . The language used predetermined “nouns” and “verbs” to execute operations. The verb pointed out 37, for example, means “Run program,” while the noun 33 means “Time to ignition.”

Now that the code is on GitHub, programmers can actually suggest changes and file issues. And, of course, they have