On things about which I have an opinion
Rsync is a great tool – incredibly powerful for synchronizing directories, copying over a network or over SSH, an awesome way to backup a mobile device back to a core network securely and other great functions. it works better than just about anything else developed before or since, but is a command line UI that is easy to forget if you don’t use it for a while and Windows is a challenge.
This isn’t meant to be a comprehensive guide, they’re are lots of those, but a quick summary of what I find useful.
There’s one confusing thing that I have to check often to be sure it is going to do what I think it should – the trailing slash on the source. It works like this:
A quick summary of useful command options (there are many, many) is:
-v, --verbose increase verbosity -r, --recursive recursive (go into subdirectories) -c, --checksum skip based on checksum, not mod-time & size (slow, but accurate) -a, --archive archive mode; equals -rlptgoD (no -H,-A,-X) -z, --compress compress file data during the transfer, should help over slow links -n, --dry-run trial run, don't move anything -h, --human-readable display the output numbers in a human-readable format -u, --update don’t copy the files from source to destination if destination files are newer --progress show the sync progress during transfer --exclude ".*" exclude files starting with "." --remove-source-files after synced, empty the dir (like mv/merge) --delete any files in dest that aren't in source are deleted in destination (danger)
I do not recommend using compression (
-z) on a LAN, it’ll probably slow you down. Over a slower (typically) WAN link it helps, but YMMV depending on link and CPU speed.
If the files really have to be accurately transferred, the checksum (
-c) option is critical – every copy function should include this.
Some of the coding tricks in H.265 have been incorporated into MPEG-H coding, an ISO standard introduced in 2017, which yields a roughly 2:1 coding efficiency gain over the venerable JPEG, which was introduced in 1992. Remember that? I do; I’m old. I remember having a hardware NUBUS JPEG decoder card. One of the reasons JPEG has lasted so long is that images have become a small storage burden (compared to 4k video, say) and that changing format standards is extremely annoying to everyone.
Apple has elected to make every rational person’s life difficult and put a little barbed wire around their high-fashion walled garden and do something a little special with their brand of a HEVC (h.265) profile for images. Now normally seeing iOS user’s insta images of how fashionable they are isn’t really worth the effort, but now and then a useful correspondent joins the cult and forks over a ton of money to show off a logo and starts sending you stuff in their special proprietary format. Annoying, but fixable.
$ sudo add-apt-repository ppa:jakar/qt-heif $ sudo apt update $ sudo apt install qt-heif-image-plugin
Firefox (52) remains my browser of choice – entirely because of plug-ins. When Firefox completely destroyed the UI/UX with “Australis,” a horrific UI change that basically made Firefox into a crappy clone of Chrome, the only thing that made Firefox usable was “Classic Theme Restorer.” Apparently, unsatisfied with the damage Mozilla had managed to wreak on their user-base with idiotic UI decisions, over the past year or so, a new version called “Quantum” (57) was rolled out that broke the functionality of almost every important plug-in.
This utterly disastrous and truly unforgivable transgression against the user-base was only slightly mitigated by sustaining 52-ESR, at least until the Sept of this year. After that, everyone who cares about having a decent alternative to Chrome will have to migrate to Waterfox.
In the mean time, one really important thing you have to remember to do if you stuck reinstalling your system on Linux (e.g. Linux Mint) is to immediately uninstall Firefox before using it even once. Then change your install version to ESR and install. If you let Quantum run even once, it will mark all your good plugins as disabled and you need to reinstall them one at a time to get them working again.
sudo add-apt-repository ppa:jonathonf/firefox-esr sudo apt-get update sudo apt-get install firefox-esr
Well, that’s the end of Firefox…. Sad to see it go after all these years, but the new plugin concept has made Firefox a subordinate version of Chrome rather than a powerful, customizable tool.
I followed these fine directions and now have waterfox running.
echo 'deb https://dl.bintray.com/hawkeye116477/waterfox-deb release main' | sudo tee /etc/apt/sources.list.d/waterfox.list curl https://bintray.com/user/downloadSubjectPublicKey?username=hawkeye116477 | sudo apt-key add - sudo apt-get update sudo apt upgrade sudo apt install waterfox
Just import your firefox preferences on starup and walla, you instant happiness with all the plugins that Quantum broke restored, including such absolute essentials as “Classic Theme Restorer” (which undoes the absolutely horrible UI changes that Mozilla adopted) and downthemall, privacy plugins, etc. If you’ve updated some plugins to be Quantum compatible, you’ll have to back those up (for me that’s things like FoxClocks and Noscript, which managed to hack together semi-viable Quantum compatible plugins after slogging through Mozilla’s buggy WebExtensions API and HTML5 quirks).
This whole translation is quite unfortunate. Waterfox is dependent on the Firefox code base, so this solution may have a finite lifespan, but for now it works and undoes the horror of Firefox 57+/Quantum.
If you haven’t already, turn off Windows update now. Microsoft has recently started installing Windows 10 spyware without consent. A good friend of mine had a bunch of systems at the company where he runs IT hacked by Microsoft over the weekend, which broke the certificate store for WPA-2 and thus their wifi connections.
To be clear, Windows 10 is spyware. Microsoft has changed their business model from selling a product to selling data – your data – to whoever they want. Windows 10 comes with a EULA that gives them the right to steal everything on your computer – your email, your private pictures, your home movies, your love letters, your medical records, your financial records – anything they want without telling you. “If you’re not paying for the product, you are the product.”
If this happens to you, I suggest contacting your state attorney general and filing a complaint against Microsoft. Hopefully a crushing class action suit or perhaps jail time for the executives that dreamed up this massive heist will help deter future corporate data thieves, though that’s certainly irrational optimism.
I wish I could recommend switching to Linux for everyone, but there’s a lot of software that still depends on Windows and a lot of users that will have a hard time migrating (developers: please stop developing for Microsoft). Apple seems unequivocally better in refusing to act as key player in bringing about Total Information Awareness. I’m not a huge fan of their walled garden and computers as overpriced fashion accessories approach, but it is far better than outright theft. For those that are slightly computer savvy, there’s Linux Mint, which is quite usable and genuinely free.
These instructions might help prevent that disaster of an update being visited upon you (and possibly law enforcement visits to come after Microsoft starts sifting through all your datas and forwarding on whatever they find). The latest reports suggest they aren’t enough, but it is the best I have found other than isolating your windows box from the internet completely.
I noticed that my avocado tree was developing brown spots on the leaves, which were almost certainly the result of Persea mites.
So I looked up some possible cures, and it seemed like introducing a predator would be the best option and the least hassle. I’d had good luck with introduced ladybugs a few years back, which formed a stable population that survived for many years after introduction. For this pest, green lacewings are recommended. I found a nearby insectary that could provide larvae on cards and they shipped them overnight.
The little guys look cute just waiting to hatch…
I hung he cards on the leaves of the tree after incubating them overnight in a warm room, and they should hatch sometime in the next day or two, as long as the ants don’t find them first…
Update 8 Sept 2016:
The green lacewings seem to have eaten all the mites. It has been 9 months and there aren’t any signs of damage to this spring’s leaves. Yay!
The new leaves that grew seem to be developing without any bites at all. The old leaves that were too damaged have fallen off, but the surviving older leaves still show the scars of the mites. Green lacewings seem to have done the trick.
Signal is an easy to use chat tool that competes (effectively) with What’sApp or Viber. They’ve just released a desktop version which is being “preview released/buzz generating released.” It is developed by a guy with some cred in the open source and crypto movement, Moxie Marlinspike. I use it, but do not entirely trust it.
I’m not completely on board with Signal. It is open source, and so in theory we can verify the code. But there’s some history I find disquieting. So while I recommend it as the best, easiest to use, (probably) most secure messaging tool available, I do so with some reservations.
- It originally handled encrypted SMS messages. There is a long argument about why they broke SMS support on the mailing lists. I find all of the arguments Whisper Systems made specious and unconvincing and cannot ignore the fact that the SMS tool sent messages through the local carrier (Asiacell, Korek, or Zain here). Breaking that meant secure messages only go through Whisper Systems’ Google-managed servers where all metadata is captured and accessible to the USG. Since it was open source, that version has been forked and is still developed, I use the SMSSecure fork myself
- Signal has captured all the USG funding for messaging systems. Alternatives are not getting funds. This may make sense from a purely managerial point of view, but also creates a single point of infiltration. It is far easier to compromise a single project if there aren’t competing projects. Part of the strength of Open Source is only achieved when competing development teams are trying to one up each other and expose each other’s flaws (FreeBSD and OpenBSD for example). In a monoculture, the checks and balances are weaker.
- Signal has grown more intimate with Google over time. The desktop version sign up uses your “google ID” to get you in the queue. Google is the largest commercial spy agency in the world, collecting more data on more people than any other organization except probably the NSA. They’re currently an advertising company and make their money selling your data to advertisers, something they’re quite disingenuous about, but the data trove they’ve built is regularly mined by organizations with more nefarious aims than merely fleecing you.
What to do? Well, I use signal. I’m pretty confident the encryption is good, or at least as good as anything else available. I know my metadata is being collected and shared, but until Jake convinces Moxie to use anonymous identifiers for accounts and message through Tor hidden nodes, you have to be very tech savvy to get around that and there’s no Civil Society grants going to any other messaging services using, for example, an open standard like a Jabber server on a hidden node with OTR.
For now, take a half step up the security ladder and stop using commercial faux security (or unverifiable security, which is the same thing) and give Signal a try.
Maybe at some later date I’ll write up an easy to follow guide on setting up your own jabber server as a tor hidden service and federating it so you can message securely, anonymously, and keep your data (meta and otherwise) on your own hardware in your own house, where it still has at least a little legal protection.
My kitchen has had halogen lighting for 20 years, from back when it was a slightly more efficient choice than incandescent lighting and had a pleasing, cooler (bluer, meaning the filament runs hotter) color temperature.
Progress has moved on and while fluorescent lights still have a lead in maximum luminous efficacy (lm/w), for example the GE Ecolux Watt-Miser puts out 111 lm/W, they’re less versatile than LEDs and installation is a hassle while low voltage LEDs are easy to install and look cool.
The goal of this project was to add dimmable, pleasing light to the kitchen that I found aesthetically interesting. I wanted a decent color rendering index (CRI), ease of installation, and at reasonable cost. I’ve always liked the look of cable lighting and the flexibility of the individual, adjustable luminaires.
I couldn’t find much information on how variable output LEDs work and what can be used to drive them. I have a pretty good collection of high quality power supplies, which I wanted to take advantage of, but wasn’t sure if I’d be able to effectively dim the bulbs from the documentation I found. So I did some tests.
I bought a few different 12V, Dimmable LEDs and set up a test configuration to verify operation and output with variable voltage and variable current. The one bit of data I had was that using standard commercial controllers, the lowest output is typically stated to be around 70% of maximum output: that is the dimming range is pretty limited with standard (PWM/Transformer) controllers. The results I found were much more encouraging, but revealed some quirks.
I used a laboratory-grade HP power supply with voltage and current control to drive the LEDs, decent multimeters to measure voltage and current, and an inexpensive luminance meter to measure LED output.
I measured 3 different LEDs I selected based on price and expected compatibility with the aesthetics of the project and because they looked like they’d have different internal drivers and covered a range of rated wattage.
These bulbs have internal LED controllers that do some sort of current regulation for the diodes that results in a weird voltage/current/output response. Each bulb has a different turn-on voltage, then responds fairly predictably to increasing input voltage with increasing output, reaches the controller stabilizing voltage and runs very inefficiently until voltage gets over the rated voltage and then becomes increasingly efficient until, presumably, at some point the controller burns out. I find that the bulbs all run more efficiently at 14V than at the rated 12V.
As a side note, to perform the data analysis, I used the excellent
xongrid plugin for excel to perform Kriging interpolation (AKA Gaussian process regression) to fit the data sets to the graphing function’s capabilities. The graphs are generated with WP-Charts and the table with TablePress.
Watts v. Volts
This chart shows the wattage consumed by each of the three LEDs as a function of input voltage, clearly demonstrating both that the power consumption function is non-linear and that power consumption in watts improves when driven over the rated 12V. Watts are calculated as the product of the measured Volts * Amps. Because of the current inversion that happens as the controllers come fully on-line, these LEDs can’t be properly controlled near full brightness with a current-controlled power supply, though it works well to provide continuous and fairly linear dimming at low outputs, once the voltage/current function changes slope, the current limiting controller in the power supply freaks out.
4W LED 5W LED 7.5W LED
Lux v. Volts
This chart shows the lux output by each of the three LEDs as a function of input voltage, revealing the effect of the internal LED driver coming on line and regulating output, which complicates controlling brightness but protects the LEDs. The 5W LEDs have a fairly gentle response slope and start a very low voltage (2V) so are a good choice for a linear power supply. The 4W LEDs don’t begin to light up until just over 6V, and so are a good match for low-cost switch mode supplies that don’t go to zero.
4W LED 5W LED 7.5W LED
Lux/W v. Volts
This chart shows the luminous efficiency (Lux/Watt, Lumen measurement is quite complicated) by each of the three LEDs as a function of input voltage, showing that overdriving the LEDs past the rated 12V can significantly improve efficiency. There’s some risk it will overheat the controller at some point and result in failure. I’ll update this post if my system starts to fry LEDs, but my guess is that 14V, which cuts the power load by 20% over 12V operation with the 7.5W lamps I selected, will not significantly impact operational lifetime.
4W LED 5W LED 7.5W LED
Total System Efficiency
The emitter efficiency is relatively objective, but the total system efficiency includes the power supply. I used a Daiwa SS-330W switching power supply I happened to have in stock to drive the system, which cost less than a dimmable transformer and matching controller, and should be significantly higher quality. The Daiwa doesn’t seem to be easily available any more, but something like this would work well for up to 5A total load and something like this would handle as many as 40 7.5W LEDs on a single control, though the minimum 9V output has to be matched to LEDs to get satisfactory dimming. It is important not to oversize the power supply too much as switch mode supplies are only really efficient as you get close to their rated output. An oversized switchmode power supply can be extremely inefficient.
With the Daiwa, driving 13 7.5W LEDs, I measured 8.46A at 11.94V output or 101 Watts to brightly illuminate the entire kitchen, and providing far more light than 400W of total halogen lights. I measured the input into the power supply at 0.940A at 121.3V or 114 Watts. That means the power supply is 88.6% efficient at 12V, which is more or less as expected for a variable output supply.
Increasing the output voltage to 14.63 Volts lowered the output current to 5.35A or 78 Watts without lowering the brightness at the installation; I measured at 168 lux at both 12.0V at 14.6V. The input current at 14.63V dropped to 0.755A or 91.6 Watts, meaning the power supply is slightly less efficient at lower output currents (as is usually the case).
- Overdriving the 12V rated LEDs to 14.63V improves plug efficiency by 20%.
At the low end, the SS-330W’s minimum output is 4.88V, which yields 12 lux at the counter or a 14x dimming ratio to 7% of maximum illumination, a far better range than is reported for standard dimmer/transformer combinations.
- 7.5W LED modules from JackyLED
- Daiwa power supply (alternate version)
- 16 gauge speaker cable
- MR-16 cable lamp mounts
- Digital light meter
(MS Excel file, you will need the
xongrid plugin to update the data as rendered in the graphs)
I’ve run across this energy drink in dramatic packaging. Energy drinks aren’t really my thing, but I thought I’d try it: slightly orange tasting fizzy water, mildly sweet with that slightly weird energy drink taste. But the bottle is fun:
It is made in Hungary and seems to be distributed more to the East than the West, at least as far as my travels have indicated. I have seen it in a lot of Middle-Eastern markets, but not in many European ones.
The lid release mechanism is kind of thematically clever.
I suspect this would be a particularly problematic beverage to forget in your carry-on luggage.
There are two things I always do with a new digital device, get a good screen protector and a good case. (And the biggest memory card that will fit).
The screen protector is pretty easy: I’ve used both Zagg and Armor Suit and prefer the Armor Suit, but not by much. Both work really well and I have an Armor Suit on my Motorola Razr V9x (still the best basic cell phone I’ve ever owned) that has lived in my pocket for many, many years without a scratch visible on the outer screen.
For cases I lived with an (almost iconic) yellow Defender case for my Blackberry Bold 9000 for about 5 years. It was awesome, indestructible, and fit the belt holder perfectly. Alas, it was no match for a random late night cab ride and early flight out of Dubai–can’t defend against that, can ya? Well, it lasted about 5 years, so no complaints. I contacted Otterbox to see if I could get a replacement silicone bit and they checked and only had 2 belt holsters left in stock from the entire product line. They mailed me those for free. Thanks Otterbox! (One did come in handy eventually.)
I got an iPod from United and, of course, got an Otterbox for it; one of the Commuter series. With a polycarbonate outer shell protecting the critical corners, and that backed underneath by a few mm of soft silicone, the iPod is extremely well protected. This is a well-engineered protection model, far better than just a layer of silicone.
A corner drop tends to generate very high localized pressure where the corner tries to merge with the hard surface it is being dropped on. Having the polycarbonate outer shell distributes that pressure load over the silicone underneath it resulting in a broad, gentile distribution of the impact load and minimizing the risk of localized overpressure which would crack plastic or glass.
Conversely, simple silicone sleeves without the polycarbonate layer, while adding critical padding and being fairly effective in most cases, can’t distribute the impact load nearly so effectively. This should not matter too much for a surface-to-surface drop where the impact force is distributed over the whole back or even an edge of the phone, but in a corner drop the silicone can be effectively mushed out of the way as the hard surface attempts touch delicate plastic or glass in a tragic romance.
I replaced the Blackberry with a Samsung Galaxy S3 and got a Commuter case for it. The case is very nice, not too big, but Otterbox did something very, very wrong. They rotated the polycarbonate tabs 45 degrees, covering the edges and not the corners. Why Otter, why? The case is still quite nice and it is the nicest looking and most comfortable I’ve found, but this is an odd engineering mistake. They talk about the “layers of protection” as a key selling point for their more expensive Commuter and Defender series, yet leave the most fragile corners protected by only a single layer. As protection goes, it is no better than the Impact since the corners are all that really matters.
The polycarbonate shell does serve to anchor the access flaps closed, which is an improvement over the iPod case, but this could easily have been achieved with a few well-placed polycarbonate fingers reaching around the case without making it difficult to assemble (too many fingers wrapping around the device make it impossible to snap the device into the polycarbonate shell).
Further, the textured silicone edges on the iPod case are actually really nice to hold, far more comfortable and slip-resistant than the polycarbonate edges of the S3 case (and make the iPod less likely to drop than the S3 as well). As an additional bonus, the iPod version exposes some textured silicone on the back surface making the case somewhat non-slip, while the S3 case is all polycarbonate on the back. Without some non-slip silicone on the back, the likelihood that the enclosed device will slip off a sloped surface and onto a hard floor or into a toilet or sink is much greater. While the case makes a disaster far less likely for the former eventuality, it is not waterproof.
While the Android OS just crushes iOS, and the availability of Android-specific tools and applications, particularly for security and encryption, makes it the best choice for a mobile device right now (though security, at least, is even less of a concern with a Blackberry – that’s the one thing Rim still has going for it – that and efficient use of data), Otterbox really could have done a better job with the case. Hopefully the S4 case will get it right.
It has been almost 2 years and I’ve been carrying the Otterbox-protected S3 more or less continuously since in a relatively active and somewhat unforgiving environment, not that anyone’s pocket or purse would fail to meet that definition. A few issues emerged:
- The rubber flap covering the USB port, which you need to access at least twice a day for charging, tore off very early on;
- I change SIMS a few times a month and the case doesn’t really like being taken on and off and eventually cracked in two places, but it still holds together;
- The unprotected silicone covering the corners began to deteriorate fairly quickly, as I predicted, and one corner has disintegrated completely, leaving that most fragile of impact points unprotected.
I’d probably buy another – two years is a pretty good life (but not as good as the 5 my blackberry gave me. I still miss that phone). I wish Otterbox would focus on protecting the corners, not the edges. The iPod case, far less heavily used but equally traveled shows no wear on the corners at all and provides the same protection it did two years ago. It is a better design.
I learned two things about Futurama recently which added to my already deep appreciation for the show. The first is that the theme song came from a very cool song by Pierre Henry called Psyche Rock from 1967, which is on youtube. It was remixed by Fatboy Slim in an appealing way.
But what was most interesting recently was to see episode 10 of season 6, the Prisoner of Benda, a spoof of the Prisoner of Zelda but including what may be the first tv-episode publication of the proof of a relatively complex mathematical theorem in group theory as a core plot element.
The problem in the plot is that the Professor’s mind swapping machine creates an immune response which prevents swapping back in one step. So how do you get everyone back to into their original bodies? Well, as Sweet Clyde says, it takes at most two extra players [who haven’t swapped yet]. As the entire cast, including the robo-bucket, have swapped bodies, the situation is pretty complex, but fortunately one of the show’s writers, Ken Keeler, has a PhD in applied mathematics from Harvard and found a proof, which is actually shown in the show (above), and then worked in a fast montage that restores everyone.
In the following table, the heading shows the character name of the body, row 0 shows the occupant of that body by the end of the plot’s permutations and before the globetrotters start the transformations. Rows 1-7 show the steps to restore everyone to their original bodies. Each transformation was animated as a pair using the two “extra players” except the last rotation to restore Sweet Clyde and the Bucket.