todd8

Personally, I wouldn't count on it, see:

[1] Metal Attraction: An Ironclad Solution to Arsenic Contamination? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1257624/

Unfortunately, a lifetime in the U.S. has left me with poor intuition for Celsius. The conversion isn't difficult to do in ones head and for laboratory work, naturally, it's just as easy to read one thermometer scale as another. For everyday life, weather reports, fever thermometer readings, thermostats and such, it is just a nuisance to convert from Fahrenheit and back. If someone tells me it's 15 degrees C outside I have to do mental arithmetic to know if I should take a sweater. Furthermore, from a purely logical perspective perhaps we should even consider using Kelvin.

It's a completely different story for distance, weight and volume. Metric measurement in these cases are more intuitive for me, and they are clearly superior too. Millimeters are so much easier to use than fractions of an inch (7/32 inch -- that's a ridiculous system). In the U.S., an ounce of flour weighs less than an ounce of gold. Who even knows how much a grain of gunpowder is in units anyone else uses (one grain is approximately 1/16 gram). There are three teaspoons in one tablespoon, but only two cups in a pint, 2 pints in a quart and 4 quarts in a gallon.

I'd be happy to switch from imperial to SI units for length, mass, and volume. I'll gladly switch slugs to kilograms and pounds to Newtons, but I will miss Fahrenheit.

I adopted two tools early on and have used them for decades: Emacs and LaTeX/TeX. Both are programmable and have an amazing set of available extensions that enhance their use. As a computer scientist it’s easy to spend time tweaking either of these flexible systems. I have to keep in mind that at some point I need to stop sharpening my axe and start chopping wood.

LaTeX takes a lot of study to become expert in it, but there are books that help. Emacs, on the hand, can be learned from the inside through its great help functionality (starting with the easy to remember Ctrl-H).

In my experience, LaTeX has the advantage of being able to handle even very complex documents and books. LaTeX can be challenging to master, but in return it can produce amazing results. See some of the references below. In particular take a look at [4] (it's a 1200 page LaTeX document) and consider if it could be written in Markdown and Asciimath. The hundreds of graphics appearing in [4] are also produced by LaTeX--the document is the manual for pgf/TikZ a popular graphic package that is itself a set of LaTeX macros.

[1] https://uva-fnwi.github.io/LaTeX/week2/maths2/

[2] https://en.wikibooks.org/wiki/LaTeX/Advanced_Mathematics

[3] https://tex.stackexchange.com/questions/397453/what-are-all-...

[4] https://pgf-tikz.github.io/pgf/pgfmanual.pdf

I learned APL on an IBM 2741 terminal[1], a terminal kind of like a teletype but with a Selectric typewriter attached to it for the keyboard and typing mechanism. This APL360 system had APL particular and idiosyncratic symbols on each of the keys (in addition to the regular QWERTY keys). The shift key selected which symbol would be produced. This made learning APL a lot easier.

The Selectric type ball was special and had the APL characters on it. Interestingly, the same kind of a system was available for ALGOL68 programming and provided symbols useful for that language.

[1] https://en.wikipedia.org/wiki/IBM_2741

An endowed public library changed my life. The McGregor Public Library in Highland Park Michigan was close to my Junior High School.

I grew up in central Detroit a few miles from downtown. The neighborhood was rough and having been assaulted many times before, I was apprehensive about walking home from junior high school. Gangs of violent kids would form up after school and it made the journey perilous. However, close to the school there was a library; it was a big library, much bigger than one would expect from the neighborhood.

I would quickly make my way to the library and hide out until around dinner time and then, when the streets were clear, I would make my way home. I'd always been a curious kid, but for the first time I started reading science magazines. I quickly graduated to reading Scientific American. I read all of the years issues (1963) and then started reading the bound issues going back over 10 years. I was fascinated with Marin Gardner's columns and the Amateur Scientist columns that appeared in every issue. I also started reading Popular Electronics around that time. I also read every math and science book I could understand in that library.

I was learning very little in the public schools they weren't good. The thugs in my classes were disruptive and prevented the rest of us from being able to have good classes. My homework and science projects were stollen or destroyed out of spite, but it was always peaceful in the library where I kept reading.

My parents finally moved from that place and I finished the last two years of High School in a suburb where all of my friends were good students and all planning on applying for college. I was quickly promoted to the honors classes and ended up as the top math and science student in a very large school. None of this would have been possible if that library had not existed. I ended up at MIT and obtained degrees in Math and EE/CS. I've been very successful and I attribute that to my love books, especially technical books, fostered by my time at the McGregor Public Library.

Sadly, that library is now closed. There is now a locked fence around the building. [1]

[1] https://www.google.com/maps/place/Highland+Park+Library/@42....

In grad school in the 80’s I used Emacs. At home around 1984 I got my first PC running MSDOS. For years I used a commercial product that used Emacs keybindings (Epsilon) because Emacs wouldn’t run on my PC.

When I went to work at IBM I was disappointed that concerns over the Gnu license forced me to use vi for a few years, but I discovered it to be great an editor for me.

I eventually was drawn back to Emacs and now, many years later, I enjoy playing with my config file every week. There is always something new to be added.

It’s org mode and magit that make it impossible to leave Emacs. (Right now I’m experimenting with a configuration where I’ve installed the top 600 most popular add on packages at once. I’m kind of using the wisdom of crowds approach to picking packages this time. Next week it will be something else.)

I believe it is my comment that you find distasteful. Please reread my post, I didn’t intend it to be dismissive of the Inuit culture. I even stated that these new numeral glyphs should be included in Unicode. I believe this aids in preserving the Inuit culture and traditions.

I myself have taken over two dozen university level math courses at the undergraduate and graduate level. I don’t need to have number bases explained to me, but I have raised three kids and recognize the challenge of helping them attain proficiency in basic grade school fundamentals. This is what motivated me to make the comment.

Ironically, perhaps, is the fact that my own ancestry includes an indigenous people living at the arctic circle who faced and continue to face racial discrimination, loss of native lands, and forced changes to their way of life, the Sámi. [1]

[1] https://unric.org/en/sami-we-are-the-natives-of-this-country...

I dislike these pseudo-scientific claims about alternative number systems and methods of paper and pencil arithmetic:

> Because of the tally-inspired design, arithmetic using the Kaktovik numerals is strikingly visual. Addition, subtraction and even long division become almost geometric. The Hindu-Arabic digits are an awkward system, Bartley says, but “the students found, with their numerals, they could solve problems a better way, a faster way.”

I think the students can be praised for having come up with simple to understand and write number system that corresponds to the conventions for counting in Alaskan Inuit language, and it seems appropriate to capture these notations in upcoming Unicode standards.

However, spending time learning base 20 arithmetic has obvious disadvantages that the article ignores. The times tables, memorized in grade school and fundamental to paper and pencil calculations, are now four times larger. Base 20 is not a popular notation for numbers. One important advantage of the number system (Hindu-Arabic) that most of the world uses is that most of the world uses it. I grew up with inches and degrees Fahrenheit and had to learn the metric system to pursue my science education. I'm glad I didn't have to learn how to count as well. We shouldn't make it harder for these kids to enjoy the rest of the world's books, journals, and internet resources about math and science.

I've seen Uni-ball 207 recommended too. I also have some Mont Blanc fountain pen ink that claims to forgery resistant (meeting ISO 14145-2) that I've used to for check writing. Here's a YouTube video about the subject [1].

Noodlers ink (also available on jetpens.com) is said to have forgery resistant inks as well. I don't have any of it, but I do have some of Noodlers invisible ink--you need an ultraviolet light source to see it.

[1] https://www.youtube.com/watch?v=tH_Yb4-0p0o

In the early 1900s, three Japanese fountain pen companies were founded: Sailor (1911), Namiki (1918), and Platinum (1919). Namiki changed its name to Pilot in the 1930s, but some Pilot pens are still sold under the Namiki brand.

I have pens from all of these companies and they are some of my favorite brands.

Featured in this list are two of my favorite fountain pens, the Pilot Vanishing Point and the Lamy 2000. Both of these in my collection write very well and both have unique and interesting designs.

The Pilot Vanishing Point doesn't need a cap, the nib is exposed and protected in a manner akin to clicking a ball point in and out. Mine works perfectly.

The Lamy 2000 is sleek and modern looking with a sophisticated design. It looks like a fountain pen that one might see in a Star Trek movie, but this model has been around since the mid 1960's. After half a century, the design is still the favorite of my collection. It operates flawlessly.

I own the other, less expensive fountain pens mentioned as well; they would be good choices too. I started out with some of these and I still like them, but it is easy to get hooked on buying more fountain pens and fancy inks.

According to the featured article, the Julia programming language is going to be used for a new and better climate model.

Slide rules are good for only around 3 significant digits, just a little more than most people’s mental math for multiplication. However, slide rules include scales for squares, cubes, trig, exponential, log functions and others.

All of these are inscribed as positions on logarithmic scales. In this manner, two scales can positioned to calculate products and quotients.

The scales, being logarithmic, are very compressed on one end, between 9 and 10 is only 5% of the scale while the interval between 1 and 2 occupies 30% of the scale (log 2 == 0.30, log 9 == 0.95).

If you can estimate measurements to a half millimeter on a precise ruler, on a one foot slide rule that corresponds to 508 divisions. Three significant digits requires 1000. With some careful interpolation while reading a slide rule it is sometimes possible to get 3 significant digits, especially in the range 1 to 2. It’s not possible to get 3 significant digits between 9 and 10.

Another limitation of slide rules is that there are no provisions for addition or subtraction. For this there were mechanical adding machines.

Notice too that all calculations are done with numbers in scientific notation. The scales start at 1 and end at 10. When calculating something like 447.8 * 1276, the slide rule is only able to calculate 4.48 * 1.28 for the user, and it gives a result like 5.73. The powers of ten have to be handled in one’s head. Furthermore, one has to understand trig well enough that having the sin only from 0 to 90 is good enough.

Because slide rules don’t give very precise answers, tables of logarithms were used for calculations requiring 4,5, or 6 digits of significance.

Between 1963 and 1965, I had a good paper route (i.e. a set of customers to which I delivered newspapers each morning before school). I found myself flush with cash. I can’t remember exactly, but I think I was paid around $7 per week.

I bought four things with this fortune: a bike, a tennis racket, swim fins, and a fancy Pickett slide rule. I sill have the slide rule with its belt holster, it sits in my office next to my desk, a memento of my early interest in math and science.

I used the bright yellow slide rule along with my abacus a couple years later as a prop in a public speaking class to explain the difference between analog and digital computers. In high school, we are expected to use slide rules for chemistry and physics classes.

My trusty yellow slip stick also accompanied me to MIT where everyone used them. They were ubiquitous. I even had friends that owned circular slide rules. In that time, when only institutions could afford electronic computer, there were even cylindrical slide rules; their helical scales being long enough to obtain a fourth digit of precision.

I needed the slide rule one more time around 1988: it was for a popular Halloween party regularly hosted by a coworker at IBM. My costume was a taped together pair of heavy framed glasses, a shirt buttoned to the top, high water pants, pocket protector full of colored pens, and my well worn slide rule holster hanging from my belt. I saw L.L., an IBM Fellow, there and he said, “Hi Todd, didn’t you realize this is a costume party.”

I once wrote a Boot loader for a minicomputer that had a card reader. One card holds 80 chars and a physical buttons on the machine would load those bytes into low memory and set the program counter to the address of the first byte. I could just squeeze in enough binary machine instructions that loaded 6 more cards of machine code that made up the rest of the boot loader. That way, a user could put these 7 cards on the front of any program they wanted to run and put it all into the card reader.

Things were actually a bit more complex, a FORTRAN program would require the compiler to be next in the stack followed by the user’s FORTRAN code and then the data that would be data read by the program.

The goal of this reading one card that would read more cards was to minimize the amount of switches that had to be set on the front panel to kick off the whole sequence. One card couldn’t even hold the final branch for the machine language loop that read cards 2 through 7. That branch instruction was at the front of card 2 that has been read into into memory by the body of the loop.

TLDR: lots of bit twiddling was needed to create an ergonomic loader.

Solar power isn't available 24 hours per day so the LCOE (levelized cost of energy) for solar is claimed be be between $59 to $91 per MWh, see [1], lets say $75/MWh, already higher than the article's $60/MWh cost for nuclear.

However, nuclear power is available 24 hours a day every day, rain or shine, summer or winter. To reach this level of availability a PV system would need to have battery back up. Let's be conservative and say 10 hours of battery is enough. This won't be enough during a hurricane or harsh winter weather with no sun for days, but let's assume 10 hours of battery is enough.

Now how much does the PV system's battery cost? I don't have figures for a 10 hour battery system. I do have an estimate based on a review of research literature for 6 hours of battery storage. According to [2], a 6 hour system in 2030 may cost under $180/Kwh. However, we've been talking Mwh not Kwh so this is $180,000/Mwh.

Unless you don't care about electricity when the sun isn't shining, nuclear is much cheaper.

[1] https://www.statista.com/statistics/493797/estimated-leveliz...

[2] https://www.nrel.gov/docs/fy21osti/79236.pdf

Interesting, much cheaper than solar.

Fascinating. I was just a kid in 1964 when I learned about fluidics. My December issue of Scientific American had an article on fluidics featured on the cover and I always wondered why there never seemed to be any applications of the devices described in that article. In particular, the use of fluidic logic gates and latches, etc.

How about this claim: pieces of string when stressed emit sounds that are picked up by nearby strings. Should be investigate this claim? What does it mean that the world of string acts this way.

For those that haven't witnessed it, I will describe a very easily constructed experiment to demonstrate this phenomena that I have discovered: first stretch a string tightly and then quickly flick it with your finger, stressing it even more. If you listen, you will hears a sound emitted by the stressed string that gradually dies off as the string recovers. Nearby strings will start vibrating in sympathy (if they are tuned properly). Could one string be communicating with the other strings?

Common objects may be used to make the experiment easier to perform: banjos, guitars, violins, etc.

My first hand accounts mostly come from my Father. He was a young Marine Corp officer on Okinawa during World War II. What a sad and terrifying time. He was stationed next to an air base on Okinawa and was issued a gas mask after the bombing of Hiroshima in preparation for the retalitory strikes they expected.

After Japan surrendered, there was a sudden shift in roles as the soldiers packed up and prepared to return the the USA. At one point, with little to do, he was offered a ride on a plane that was heading over to the mainland of Japan for some reason. He got to see Hiroshima and Tokyo, spending some time on the ground and interacting with a few Japanese citizens there. My father passed away a couple of years ago and I wish that my brother and I could have recorded his accounts of some of these things.

I think you are right, at least from what I've read; I have to admit to no actual experience with actual, modern hardware construction.

Maybe some day I'll try tinkering with a hardware project again. I was in college when 555 timers, 741 op amps, and 7400 logic gates were the basic building blocks for simple projects. Electronics, even at the hobby level, is quite different now.

I never really lost interest in hardware after my EE college work, I just got more and more interested in software and did all of my graduate and professional work on the CS side.

My digital design class in the mid 1970s used the older RTL (resistor-transistor logic) gates. They had only 2 NOR gates per (TO-5) package; you can still buy these on Ebay for around $6.

At the time I wished that I could be using the much newer 7400 family of logic chips; the 7400 series by then had a full complement of chips available, everything from logic inverters to 4 bit arithmetic-logic chips (74181). The 7400 family is TTL and much better: higher density (4 NAND gates per chip for the 7400), easier to work with packaging (DIPS), higher speed, much greater variety of chips, and most importantly to me a higher fanout (each output signal can drive inputs on more downstream chips making designs simpler).

The 74HC family used in the featured article came along around 20 years later. Many families of 7400 have been introduced over the years[1]. The 74HC family was one of my favorites for personal projects. They where logically compatible--the 1960s 7400 and the 1980s 74HC00 chips are both four 2-input NAND gates having the same pinouts in the same packages (14 pin DIPs). The reason I liked 74HCs was the fact that they used CMOS transistors and hence required very little power and could run on a wide range of voltages allowing simple battery powered circuits. I still have a supply of these from the 1990s that I bought for home projects.

By now, half a century later, there are even more varieties. Some are suitable for hostile environments (like automotive applications--high temperature, wide voltage swings, electrical noise, and vibrations). Some will run on voltages under one volt and all run much faster. See [1] from Texas Instruments.

[1] https://www.ti.com/lit/sg/sdyu001ab/sdyu001ab.pdf?ts=1680318...

The Pentax 645 was one of my favorite cameras, but years ago I saw that the future was digital. My second consulting contract was for Kodak in late 1990. They were developing a software/hardware platform to support digital media. A few years after that I sold off my medium format cameras (Pentax 645 and RZ67). I like working with direct digital much better. I do wish I still had my beautiful view camera; it was stolen by contractors working on my house :(.

Now, the majority of my photos are family and vacation photos taken on my iPhone.

Algol 60, Algol W, and Algol 68 were influential in the historical development of subsequent programming languages. C gets its type on the left order from the Algol family.

Pascal, Modula, and Ada are all type on the right languages and were also very influential in the historical development of programming languages. I happen to prefer types on the right for complex declarations. Note that Pascal and Modula were designed by Niklaus Wirth after he created Algol W; it seems he preferred types on the right.

I was in elementary school in Detroit (a city in the US) during the 1950's and the only name I ever heard used for that ubiquitous playground device was "monkey bars". I really enjoyed them as a kid.

I am not the poster you are replying to but calling that post “bad faith participation” surprised me. Stopping ethanol production will lower demand for corn so it is conceivable that this would reduce the marginal value in producing corn and cause some amount of corn production to become worth less than the alternatives (like planting different crops or less intense farming of corn field, etc.)

To me at least, not being an agricultural economist, the statement that the corn would be grown anyway wasn’t obvious on the surface; I too would have liked to have seen some further justification for the claim.

Macros provide abstractions that often make programs easier to understand. I myself have dozens of the usepackage macro in my Emacs configuration, they hide and standardize the boilerplate that I could use instead. Nevertheless, I have serious reservations about macros in programming.

Taking a code base and expanding the macros to see whether that is more or less readable is a bit like expanding a C++ class hierarchy into assembly language and concluding that this program’s object oriented design is great because it is more readable than the resulting assembly language.

The real question is whether or not there are better alternatives than macros or metaprogramming in the first place. Functions, especially as found in modern languages[1], have proven to be very useful abstraction mechanisms and can often mitigate the lack of fancy macros.

I don’t want macros banned from Lisp, but I don’t miss them in other programming languages. Over exuberant use of fancy macros in Knuth’s brilliant TeX, in my opinion, contributes to the glacial pace of LaTeX development.

[1] By this I mean functions with circumscribed access to non local variables, provisions for choices of ownership of parameters, static scoping, first class functions, closures, and recursion.

I find the big advantage of rolling to be easier access to the rolled items at my destination. I can pick a rolled shirt or pants to wear without rooting through a stack of folded clothes, which usually results in some of the stacked items getting wrinkled.

According to Wikipedia, Polonium is 5000 times more radioactive than Radium (just 0.001g of Po emits the same number of particles as 5g of Ra).

It has a half life of just 138 days so in only 4.6 years the missing Polonium will be equivalent in radioactivity to Radium, which is known to cause cancer. This doesn't sound like something that should be treated lightly.