The Best Lead Grade For Every Application

For thousands of years, people have used graphite to exercise creativity and bring ideas to life. Graphite is the key component of modern day pencil lead—in fact, lead is a misnomer as it’s actually made up of a mixture of graphite and clay. The formulation of this mixture determines its lead grade. The higher the proportion of graphite content relative to clay the lead has, the softer and darker the lead will be, and vice versa.

Lead grade is an important consideration for both the artist and writer. The hardness of a lead affects its strength, smoothness, smudge resistance, and pigmentation. Writers can fine tune the darkness of their lines by moving a step up or down in lead hardness, while an artist can employ the full range of lead grades to achieve different effects.

-Miriam. “The Best Lead Grade For Every Application.” JetPens.com. August 27, 2019.

Probably more than you want to know on the topic of selecting a pencil.

Vertiwalk: An Alternative to Stairs

“Vertical Walking is a new system to move yourself between floors in a building. By exploiting the potential of the human body and materials, only a fraction of effort is required, compared to taking stairs. No external energy is needed.”

http://www.vertiwalk.com

The intersection of how making things working for folks that are differently abled due to disease, age or some other issue and how that opens up new ways of looking at things for everyone else is really interesting. In the United States, your lifetime chance of dying from a fall is 1 in 114. The CDC states: “Every second of every day in the United States an older adult falls, making falls the number one cause of injuries and deaths from injury among older Americans, [for a total of 27,000 each year].

Changing the stair paradigm could make our residences much safer. It would also open up new architectural options.

Eliminating Rust

“The story is, Australian sheep farmers noticed that steel things that sheep often rubbed against did not rust. Sheep’s wool is thick with lanolin, which is removed in processing the wool. Soap makers use it, it is also used in cosmetics.

One pound of anhydrous lanolin from eBay costs about $16. I mix it about 10:1 with light oil and apply with a brush or cloth. I also mix it with WD40 in a trigger spray. A pound goes a long way.

Since starting this about 10 years ago, rust is a thing of the past – except where I failed to apply this mixture. It has been 100% effective.”

Gareth’s Tips, Tools, and Shop Tales – Issue #7
And if you have an item that already has rust, there’s Evapo-Rust.

And if you have an item that already has rust, there’s Evapo-Rust.

New Kilogram Standard

“Officially, in the US, 1 pound is defined as 0.45359237 kilograms. A foot is defined as 0.3048 meters…

[As of today, the kilogram is being redefined in terms of Planck’s constant, which we only recently measured accurately enough to derive kilograms from it to an acceptable level of accuracy:]

The kilogram, symbol kg, is the SI unit of mass. It is defined by taking the fixed numerical value of the Planck constant h to be 6.626 070 15 × 10-34 when expressed in the unit J s, which is equal to kg m2 s -1 , where the meter and the second are defined in terms of c and ∆νCs.

[And this has happened before with the meter:] By 1983, physicists had gotten really good at measuring the speed of light. So they used it to fix the length of the meter forever, to make it permanent. Here’s how: They redefined the meter to be equal to the distance light travels in a vacuum in 1/299,792,458 of a second. Essentially, the definition of the meter is now baked into the definition of the speed of light…”

—Brian Resnick, “The world just redefined the kilogram.” Vox. November 16, 2018.

Knife Missiles

“Designated the Hellfire R9X, the missile has no explosive warhead—instead, its payload is more than 100 pounds of metal, including long blades that deploy from the body of the missile just before impact.

‘To the targeted person, it is as if a speeding anvil fell from the sky,’ according to the WSJ. Some officials referred to the weapon as ‘the flying Ginsu,’ because the blades can cut through concrete, sheet metal, and other materials surrounding a target.”

—Sean Gallagher, “Drones used missiles with knife warhead to take out single terrorist targets.” Ars Technica. May 9, 2019.

Coming soon to a law enforcement department near you. Thanks, Iain M. Banks (no. 6); I feel safer already!

Learn to Program With Common Lisp

Tim Ferriss has a currently popular blog post, “Ten Lessons I Learned While Teaching Myself to Code,” that I’ve seen mentioned in a few places. While it is largely good advice, there is one point that is wrong. It does matter what language you learn. Here’s the ten lessons from his article:

  1. The online world is your friend, start there.
  2. Don’t stress over what language to pick.
  3. Code every day.
  4. Automate your life.
  5. Prepare for constant, grinding frustration.
  6. Build things. Build lots of things.
  7. “View Source”: Take other people’s code, pick it apart, and reuse it.
  8. Build things for you—code you need and want.
  9. Learn how to learn.
  10. Reach out to other coders.

The programming language you choose matters. If what you are doing is trivial, then yes, you can use any programming language. To quote from Paul Graham’s essay, “Revenge of the Nerds“:

“The disadvantage of believing that all programming languages are equivalent is that it’s not true. But the advantage is that it makes your life a lot simpler. And I think that’s the main reason the idea is so widespread. It is a comfortable idea…There are, of course, projects where the choice of programming language doesn’t matter much. As a rule, the more demanding the application, the more leverage you get from using a powerful language. But plenty of projects are not demanding at all. Most programming probably consists of writing little glue programs, and for little glue programs you can use any language that you’re already familiar with and that has good libraries for whatever you need to do. If you just need to feed data from one Windows app to another, sure, use Visual Basic.”

Tim Ferriss is writing trivial programs. So, for his use case, the choice of language is irrelevant. It might be for your use case as well.

But, computer languages are not the same. They have different strengths and weaknesses. For example, in this blog post, a professional programmer discusses why Rust is not a good replacement for C. The short version, Rust is a young language that isn’t stable, and it lacks features older languages have, such as a specification.

Some languages are simply more powerful, mature and give you more options. If you are going to go through the trouble to learning how to program, why not ground yourself in a language with more capabilities?

Your first choice of programming language is going to shape how you think about programming. It can take a long time to broaden your sense of the possible if you pick a language with limited features when you first start learning.

There are many good, powerful programming languages. Arguments can be made for any language you like. However, Paul Graham’s article mentioned above makes a good case that Lisp is a very powerful language. In Pascal Costanza’s Highly Opinionated Guide to Lisp, there’s an interesting observation:

…”Lisp is, in some sense, the mother of all [computer programming] languages…the mindset of Lisp asserts that expressive power is the single most important property of a programming language. Nothing should get in your way when you want to use that power. A programming language should not impose its view of the world on the programmer. It is the programmer who should be able to adapt the language to his/her needs, and not the other way around.”

Lisp is old. It’s stable. It is powerful. Textbooks teaching it date back to the early 1990s. But, they are still relevant and can be bought for almost nothing. So, why not learn Common Lisp? It’s a good question. The most common answer is that computer programming languages are subject to fads and new languages are more popular. But, given Lisp’s flexibility, it’s difficult to make the case that they are better.

Ok, suppose for a moment I’ve convinced you. Now, the question is: how do you go about learning Common Lisp? Last year, Steve Losh provided an answer. He put together a blog post called “A Road to Common Lisp,” that explains the Lisp language in detail and how he went about learning it. In short:

  1. Install SBCL or if you’re using MacOS and want a single GUI app you can download from the App Store, choose Clozure CL. My preference is for Emacs, SBCL, quicklisp and SLIME (tutorial), but you should use an editor that is comfortable to you that can balance parentheses, highlight comments and strings, and autoindent Lisp code. Atom can be a good choice if you haven’t use a text editor before. But, it would be better if you learned either Emacs or Vim.
  2. Read Common Lisp: A Gentle Introduction to Symbolic Computation (<$2 on Alibris, online for free). Do all the exercises and grok in fullness. This book is aimed at intelligent beginners with no prior programming knowledge. Take your time and noodle with this text. It’s going to take time to develop a fluency, and it’s a different style of thinking.
  3. Then read Practical Common Lisp (<$25 on Alibris, online for free). Work through some of this book every day until you complete it. Type in the code if it is going to help you understand it. It doesn’t have exercises.
  4. Write some code for something easy, e.g., Project Euler.
  5. Then, flesh out your understanding further with Paradigms of Artificial Intelligence Programming (<$25 on Alibris).
  6. Now, you’re ready to program something serious and need a weighty reference text, i.e., Common Lisp Recipes (<$50 on Alibris).
  7. Finally, I suspect that Patterns of Software: Tales from the Software Community (<$10 on Alibris) is recommended because it’s a help with understanding how to work on software projects, but the purpose of the recommendation is kept unclear to prevent spoilers.

This strikes me as a better alternative than a $11,000 boot camp. Depending on how much you want to learn, you can get the tools you need to learn Common Lisp to the level you want for somewhere between $0-$150. All the software is available at no cost, and it will run on any computer you already own. Then, if you want to branch out and learn Python, Javascript, or some other language, you’ll have an excellent foundation. However, if you try learning Python or Javascript and then try to learn Lisp or another more powerful language, you’ll find it to be a much more difficult task.

Good luck!