November 27, 2019 3:42 PM

Maintaining an Online Presence

Earlier this year, many people were passing around this article about "re-learning how to be yourself online". Near the end the author reaches a set of questions that are motivating him:

Here I was retreating from the web because I thought my online presence was unimportant and inconsequential. Meanwhile, a foreign power was using its resources to pretend to be someone like me to try to influence someone like me. What kind of influence does that mean I really have? What kind of influence does that mean each of us has? And who fills that vacuum if we fail to fill it ourselves?

Given the size of my following on Twitter and the size of my blog's readership, it's easy for me to think my online presence is unimportant or inconsequential. When time gets tight and work crushes me down or other interests call, feeling that my writing is inconsequential can be all that it takes not to take the time to write. I have to remind that that is never been why I tweet or blog.

With so much of modern life happening online, sometimes it can feel as if online writing has much higher stakes than it really does, especially for someone with my limited audience. It's worth reminding ourselves that tweeting and blogging can be simple reflections of who we are, nothing more and nothing less. The stakes don't have to be high, and our influence can be small. That's okay. Writing has its own benefits, and connecting with readers, however few there might be, is a bonus.

I am unlikely ever to write much about politics here, so my influence is unlikely to fill a space coveted by foreign powers. Whatever influence I may have will come from being myself. I need to overcome the inertia of busy days and make time to write.

Actually, that is not quite right. Much as I mention in my first blog entry ever, linked above, I have amassed a folder of ideas for blog entries. I also have a single org-mode file containing entries to write. Some, like the item that became this post, consist only of a quoted passage or some other trigger and a single idea waiting to be expanded. The most depressing items in the file are a seemingly endless collection of partially-written posts, some nearly finished, that never quite crossed the finish line.

So: I need to overcome inertia and make time to finish. That is easier said than done some days. Writing takes time, but finishing often takes a surprising amount of time. Finishing also means putting the words out in the world for others to read. That feels risky for many different reasons, and our minds can trick us into thinking we are better off saving the file somewhere and never finishing. But I like to think and write, and connecting with readers, however few there might be, is a bonus.

Oh, and as we in America enter a long weekend dedicated to gratitude, I thank all of you who are still reading my blog after all these years. I appreciate that you spend even a few of your scarce minutes reading what I write. Indeed, I marvel at it. I hope you find it time well spent.

Posted by Eugene Wallingford | Permalink | Categories: Personal

November 25, 2019 6:06 PM

Demonstrating That Two Infinities Are Equal

I remember first learning as a student that some infinities are bigger than others. For some sets of numbers, it was easy to see how. The set of integers is infinite, and the set of real numbers is infinite, and it seemed immediately clear that there are fewer integers than reals. Demonstrations and proofs of the fact were cool, but I already knew what they showed me.

Other relationships between infinities were not so easy to grok. Consider: There are an infinite numbers of points on a sheet of paper. There are an infinite numbers of points on a wall. These infinities are equal to one another. But how? Mathematician Yuri Manin demonstrates how:

I explained this to my grandson, that there are as many points in a sheet of paper as there are on the wall of the room. "Take the sheet of paper, and hold it so that it blocks your view of the wall completely. The paper hides the wall from your sight. Now if a beam of light comes out of every point on the wall and lands in your eye, it must pass through the sheet of paper. Each point on the wall corresponds to a point on the sheet of paper, so there must be the same number of each."

I remember reading that explanation in school and feeling both amazed and enlightened. What sorcery is this? So simple, so beautiful. Informal proofs of this sort made me want to learn more mathematics.

Manin told the story quoted above in an interview a decade or so ago with Mikhail Gelfand, We Do Not Choose Mathematics as Our Profession, It Chooses Us. It was a good read throughout and reminded me again how I came to enjoy math.

Posted by Eugene Wallingford | Permalink | Categories: General, Personal

November 10, 2019 11:06 AM

Three of the Hundred Falsehoods CS Students Believe

Jan Schauma recently posted a list of one hundred Falsehoods CS Students (Still) Believe Upon Graduating. There is much good fun here, especially for a prof who tries to help CS students get ready for the world, and a fair amount of truth, too. I will limit my brief comments to three items that have been on my mind recently even before reading this list.

18. 'Email' and 'Gmail' are synonymous.

CS grads are users, too, and their use of Gmail, and systems modeled after it, contributes to the truths of modern email: top posting all the time, with never a thought of trimming anything. Two-line messages sitting atop icebergs of text which will never be read again, only stored in the seemingly infinite space given us for free.

Of course, some of our grads end up in corporate and IT, managing email as merely one tool in a suite of lowest-common-denominator tools for corporate communication. The idea of email as a stream of text that can, for the most part, be read as such, is gone -- let alone the idea that a mail stream can be processed by programs such as procmail to great benefit.

I realize that most users don't ask for anything more than a simple Gmail filter to manage their mail experience, but I really wish it were easier for more users with programming skills to put those skills to good use. Alas, that does not fit into the corporate IT model, and not even the CS grads running many of these IT operations realize or care what is possible.

38. Employers care about which courses they took.

It's the time of year when students register for spring semester courses, so I've been meeting with a lot of students. (Twice as many as usual, covering for a colleague on sabbatical.) It's interesting to encounter students on both ends of the continuum between not caring at all what courses they take and caring a bit too much. The former are so incurious I wonder how they fell into the major at all. The latter are often more curious but sometimes are captive to the idea that they must, must, must take a specific course, even if it meets at a time they can't attend or is full by the time they register.

I do my best to help them get into these courses, either this spring or in a late semester, but I also try to do a little teaching along the way. Students will learn useful and important things in just about every course they take, if they want to, and taking any particular course does not have to be either the beginning or the end of their learning of that topic. And if the reason they think they must take a particular course is because future employers will care, they are going to be surprised. Most of the employers who interview our students are looking for well-rounded CS grads who have a solid foundation in the discipline and who can learn new things as needed.

90. Two people with a CS degree will have a very similar background and shared experience/knowledge.

This falsehood operates in a similar space to #38, but at the global level I reached at the end of my previous paragraph. Even students who take most of the same courses together will usually end their four years in the program with very different knowledge and experiences. Students connect with different things in each course, and these idiosyncratic memories build on one another in subsequent courses. They participate in different extracurricular activities and work different part-time jobs, both of shape and augment what they learn in class.

In the course of advising students over two, three, or four years, I try to help them see that their studies and other experiences are helping them to become interesting people who know more than they realize and who are individuals, different in some respects from all their classmates. They will be able to present themselves to future employers in ways that distinguish them from everyone else. That's often the key to getting the job they desire now, or perhaps one they didn't even realize they were preparing for while exploring new ideas and building their skillsets.

Posted by Eugene Wallingford | Permalink | Categories: Computing, Teaching and Learning