A checksum is a small number that is generated from a larger number which allows you to quickly check whether or not the larger number has changed. It’s a very handy tool when transferring large files on a computer, since you can instantly check whether any bits of the file have been corrupted or altered without slowly and painstakingly comparing every bit. This concept is everywhere, probably even in your pocket.
If you look at the 16-digit number on a credit card, the last digit is actually a check digit: a number generated from the 15 other digits by a simple yet clever algorithm. When you type your credit card number into a website, that algorithm tests the credit card number against the check digit, instantly revealing any typos without needing to compare that number to the entire Visa database. ISBN, VIN, and bank routing numbers all contain check digits for the same reason – they provide a really quick way to spot errors.
I’ve often wished there was an easy way to apply this concept in other areas, like knowing that pages 27 and 159 of a book will always show if the whole thing is any good, or that track 6 of a CD will instantly define the rest of the entire album. While it is never as mathematically clear as it is with credit card numbers, we can judge books, music, and entire worldviews by looking at a sample of what they produce, or the most basic and foundational ideas behind them. In scripture, we see examples of this in recognizing a plant by its fruit, or in this passage from 1 John:
Heidi and James and I are at the Noah Conference this weekend, along with a lot of our family and about 2000 friends. We’ve had a lot of great conversations, a lot of exciting stories, and heard a lot of great lectures. Five of the Botkin kids also got to give a talk this afternoon, entitled “What Our Parents Taught Us to Do with Our Lives” where we talked about nine spiritual tools that they gave us to build with.
When our parents were raising us, they gave us specific goals, goals like service, making disciples, meeting needs, and ultimately seeking first God’s Kingdom and His righteousness. But they also gave of a lot of tools to help us work to meet those goals. The list of things that our parents worked hard to give us is unending, but for the sake of brevity, my siblings and I sat down and we distilled nine really key tools:
Last week Douglas Wilson wrote an excellent blog post mentioning Calvinball, a game invented by Calvin and Hobbes author Bill Watterson. While Wilson’s main point is the need for Christians to maintain consistent definitions in the cultural battles that rage around us, he got me thinking about what a brilliant metaphor Calvinball is for the aggressive relativism of our day.
Bill Watterson, easily the best comic strip writer and artist since Walt Kelly, was an extremely gentle satirist. While he would occasionally poke fun at academic double-speak, the shallowness of mass media, or modern artists, I’m sure that Calvinball was not meant to represent the philosophical system behind post-modern thought. It’s merely the spontaneous creation of an extremely self-centered six-year-old trying to have everything his own way. On second thought, how could the game not exactly reflect the liberal ideal of total moral relativism?
Calvinball is the perfect representation of a game with no rules, no standards, and nothing to stop you from changing absolutely everything about the game all of the time. As Doug Wilson points out, there’s no point in playing a game, or having a conversation, when the definitions are totally fluid and even the goal of the argument is in flux. For one thing, it becomes impossible keep track of the score.
When I lived in New Zealand, I learned a little bit about the sheep business. It’s handled differently there than in the rest of the world, particularly on the South Island, where sheep farmers run exceptionally large flocks. The typical practice is to send the sheep out to forage for themselves, up into the hills and mountains, and there isn’t much messing around with fences and paddocks. At shearing time, the sheep are mustered together back at the station, usually by part-time hands using dogs and ATVs. After the sheep are sheared and dipped, they get sent back into the wilderness to continue fending for themselves.
New Zealand’s average flock size is 3000 ewes, with an estimated 7000 sheep per shepherd ratio. This farming method really only works because this unique island nation has a very mild climate, a great abundance of forage, and a complete lack of predators. The rest of the world is generally less forgiving to wandering sheep.
In the Bible, we see Jacob and Moses leading their flocks far, far afield in search of food and water. David has to defend his sheep from lions and bears. Psalm 23 describes a shepherd as being constantly close to his flock, providing all of their sustenance, protection, and comfort. He goes into the wilderness with his flock. He experiences all of the same discomforts and dangers that they do, no matter if it is rough terrain, bad weather, or deadly beasts.
While there are many American megachurches that to follow the Kiwi model – sending thousands of sheep wandering into the wilderness to look after themselves, only sporadically rounding them up for fleecing and dipping – the New Testament makes it clear that elders and deacons are meant to imitate the shepherds of the Old Testament. 1 Peter 5, after four chapters of exhorting us to put off unrighteousness and put on more holy behavior, even in trials, says this:
Last week Isaac showed you our own homemade contraption using the Toddy felt filters, mason jars, plastic mason jar caps. Now that I’ve been testing it for a couple of week, I’ve decided what I like best. Here are all the things that I have tested so far:
Toddy Cold Brewer
The system that inspired our experiment was a gadget my sister owns, called the Toddy system. A simple plastic brewing container rests over the top of a carafe or mason jar. You layer coffee and water in the top portion, and let it sit 12-24 hours. Then you remove the cork plug at the base of the plastic container, and it slowly drips through a small felt filter into the mason jar below. Some aficionados claim it produces a clearer, less cloudy brew, since you aren’t stirring or disturbing the grounds as you prepare to filter it. You end up with approximately 5-6 cups of cold coffee at the end, so it doesn’t have a huge capacity. It’s one more gadget that I don’t have room for in my kitchen right now, but I love the simplicity. Also, at $35 for the initial investment, and then $2.50 for felt replacement filters, it’s not cheap.
Isaac’s Hourglass Invention
While this thing was fun to experiment with, it’s a bit of trouble to assemble. Which way does that straw go in? Which side do I screw to which jar? Every time I put it together I felt like it was an IQ puzzle meant to test my spacial awareness. And since it uses the Toddy filters, you still have the downside of needing to occasionally buy new ones. The upside is that I can use the mason jars I already own, the half-gallon jars make enough for almost a whole week for the two of us, and the only cost is teo wide mouth plastic caps, one narrow mouth plastic cap, a little caulk, glue, and a long straw. It works perfectly, but it’s more parts to disassemble, wash, and reassemble.
A couple of weeks ago, celebrity astrophysicist, podcaster, and TV host Neil deGrasse Tyson proposed an entire system of global government in a single tweet: “Earth needs a virtual country: #Rationalia, with a one-line Constitution: All policy shall be based on the weight of evidence.” This concept is admirable for its brevity… but not much else. While this particular hashtag hasn’t exactly gone viral (less than 400 posts so far), it has had a lot of reach (almost 800,000 viewers). It’s also generated a lot of discussion elsewhere, and US News, Slate, and Popular Science have all published op-eds attacking this popular scientist’s idea, and from several different angles.
Popular Science pointed out that science is merely an evolving tool. Slate’s Jeffrey Guhin lammed scientism, claiming that creationists are as scientifically adept as their evolutionist counterparts, and yet despite all this science they are still wrong. Robert F. Graboyes wrote for US News about several blood-soaked times that this “rational society” idea has been tried throughout history, and it’s a good read. We should never forget the “Temples of Reason” that presided over the French Reign of Terror, the sheer bodycount of “scientific socialism,” or the creeping horror of eugenic engineering.
But none of these articles criticizing the idea of science as a holy and pure ideal are complete. It is obvious that definitions of science change, and that imperfect human scientists will have flaws and foibles. It is even obvious that facts are not self-evident and statistics do not speak for themselves. Facts do not judge; they are judged. All evidence must be interpreted. All interpreters will have a lens through which they view the raw data; a worldview that shapes their conclusions.
In case our readers hadn’t noticed yet, it is now completely summertime (here in the Northern Hemisphere, anyway). Our air conditioning is running for a lot of the day, James is a little less excited about playing outside right after his morning nap, and Heidi and I are pretty much only drinking coffee that is full of ice.
We aren’t really coffee aficionados, but do we usually grind our own coffee and brew it in a French press like some coffee snobs swear by. Now that it’s warmer, we’ve begun cold-brewing our coffee, and despite the fact that cold-brewed coffee has a different flavor and possibly less caffeine, we like it. For those that haven’t tried the now popular practice, cold-brewing involves steeping ground coffee in much cooler water for a much longer time. We use room temperature water and let it steep for about 24 hours.
It’s just as easy to make, as long as you prepare the coffee far enough ahead of time that it will be ready when you want to drink it. We’ve been making tomorrow’s coffee right after pouring today’s coffee that we started brewing in our French press yesterday. However, the French press doesn’t hold too much, and it doesn’t filter out quite all the grounds. As usual, I thought there could be a better way.
The L16 camera is the latest consumer-accessible version of a scientific imaging technique called computational photography. Now to some extent, all digital photography is computational photography. For example, all CMOS sensors that use a Bayer color filter require computational models to interpolate what the color values are in each of the pixels that they capture.
But what the L16 does is much more complicated. Instead of a recording the photons collected and focused by a single lens, it has 16 sensors and 16 lenses. There are some significant advantages to this. First of all, the total surface area of the sensor array can be increased by adding more small lenses, instead of increasing the size and weight of a single big lens.
This is not a new idea, in fact this is exactly how an insect’s compound eye works: many tiny lenses capture many images that the insect’s brain instantly comprehends as one image. The L16 does this a bit slower, taking the data from 16 different sensors and 16 different lenses, and assembling it into a single image that should have greater detail, less noise, and some additional data that a single sensor could not have captured on its own.
It’s now been one week since the historic vote for British Independence, and the Brexit celebration and the Brexit panic have been colliding ever since. The Pound has yet to recover from that panic, but the $3 trillion dollars that journalist claimed had been evaporated, vaporized, or wiped out of the global markets has mostly come back. Amazing, how wealth can vanish into thin air, and then just as quickly reappear, right out of thin air, just like that.
Anyhow, in the last week, Britain’s angry “Remainers” have had time to publicly demand that their politicians not listen to public demands, and the EU’s angrier officials have been constantly breathing out threats and demands against the UK. In addition to possible embargoes and boycotts, the EU is how moving to punish British voters by banning the appliances that make their beloved tea and toast. There is even talk of war.
Prime Minister David Cameron, for example, has fretted that without the EU’s protection and advice, the UK and other European powers might be plunged into foolish and costly foreign wars (like the recent Gulf wars, perhaps?). Some analysts have gone further, suggesting that the only thing preventing bloody wars between European nations has been the benevolent oversight of the European Union. Without its British backing, the collapse of the EU is possible, which these fearmongers say would immediately spark a new series of European Wars, possibly a new World War.
Despite the underwhelming response to Google Glass and the overwhelming hype surrounding various VR headsets, it’s pretty safe to say that the future of head-mounted displays is very bright. And while most folks are excited about the gaming potential of immersive displays like the Oculus Rift, I think that transparent Augmented Reality displays like Microsoft’s HoloLens will get more overall use, simply because they can be used for more things.
However, all of these displays seem too expensive, too big, too delicate, and too early in development to have any apps for your personal job. I’d love to have a little screen sitting just under my right eye showing me my emails, camera viewfinder, CNC machine terminal, caliper display, and so on, but that technology is a little far off, and who knows how useful it would actually be in day-to-day practice? I think it’s worth building something that’s a little simpler to implement for the sake of experimentation.
I think that someone should build a basic Bluetooth headset with a little microphone boom which has a multi-color LED on the end. I don’t think it would need to be much longer than two inches to get that flashing LED into the wearer’s peripheral vision (try this yourself with a tiny LED and let me know what you find), and little plastic prism would direct the light toward the eye and away from other folks.