A job posting just listed something like, “Experience using TCP/IP” as a requirement.
I’ve been using it since the fifth grade or so, when we networked two PCs together. I now use it on a daily basis. I’ve used it very extensively, including billions of ACKs, millions of SYNs and FINs, and even some RSTs and PSHs.
But I’m not just being a goofball. The job doesn’t seem to entail any low-level knowledge of TCP/IP. I think they’re just looking for someone who knows what it is. (I also have extensive experience using ICs, device drivers, and OS kernels.)
Is it just me, or has the “news” ceased to be…. new? I don’t really watch news on TV much, simply because I can justify sitting in front of the computer as being semi-productive, but if I sit down in front of the TV, I’m guaranteed to be 0% productive. Plus, I prefer the news online where I can get it from multiple sources, sometimes even primary sources.
But here’s the news I’m seeing:
Austria’s Fritzl, the guy who locked his daughter up in the basement for decades and fathered six of her children, is apparently mentally ill. This was immediately apparent to me, and the news article ceased to be “news” a few days ago.
The pregnant bank teller that was shot and had her baby die? Tragic, but it happened last week. You can’t run “follow-up stories.” It’s over.
Obama and Hillary are facing off in elections.
Some colleges allow male and female students to room together if they choose to. This has been a headline in GMail for about three days for me, and it wasn’t interesting the first time.
Zimbabwe’s elections are screwed up.
The Texas polygamist ranch. It’s a big issue, maybe, and has all sorts of implications. But I don’t care anymore!
I came across Ken Rockwell’s site the other day, and, as I perused a lot, I came across his interesting mention of the Casio EX-F1. I’ve “graduated” from integrated point-and-shoots to digital SLRs, although this camera costs more than my digital SLR and three lenses put together.
Photographically, it’s mediocre. 6 megapixels. Except you don’t buy this thing for its resolution. You crave it because:
60 frames per second at 6 megapixels. (Note that most movies are shot at 24 fps.)
“[S]tereo HDTV movies,” although I confess that I’m not quite sure what that means.
Continuous shooting mode, where it’s just constantly shooting at 60fps, and, when you hit the shutter, saves the ones around that time. Thus, you can actually get shots from before you click the shutter.
A maximum shutter speed of 1/40,000 second. That is not a typo.
60 frames per second is ridiculous. But if you can take a cut in resolution, you can go further, all the way to 1,200 frames per second at a pitiful 336×96.
Actually, 336×96 isn’t just tiny, it’s a really weird size. I’ve resized (and cropped) a random photo of mine down to 336×96:
In conclusion… 6 megapixel camera, with a long zoom lens equivalent to 36-432mm. And it’s an HDTV video camera. And it’s got the crazy bonus of letting you use shutter speeds of 1/40,000 of a second, and capture low-res video at 1,200 frames/second. I wouldn’t carry it as my main camera (though it would probably be entirely usable for that), but I’d love one of these in my bag for video and such.
I also wonder about the “trickle-down” effect. Although really, more like the “trickle-out effect.” Nikon’s D3 will give pretty clean shots at ISO 6400, something no other camera even tries to offer. It goes up to ISO 25,600. Canon and Nikon are very close when it comes to the frames-per-second rate of their high-end digital SLRs; 7-9 frames/second. (Hint: get rid of the shutter, which is useless on a digital camera where you can just “read” the sensor for a given period of time.) Companies keep focusing on packing more and more megapixels into smaller and smaller sensors. As I’ve said before, I have a 20×30″ print from my 6-megapixel camera. (Cropped a bit, too, actually.) I only “upgraded” to my 10-megapixel XTi because the old one broke and you can’t buy a 6-megapixel SLR anymore. Maybe, just maybe, we’ve seen an end to the megapixel arms race. We exceeded the resolution you could squeeze out of film a long time ago, and now we’re giving medium format a run for its money. When I go to buy a new SLR in maybe five years, I don’t want it to be more than 10 megapixels. But I hope that it goes a lot further than 6 megapixels. And if a “prosumer” point-and-shoot camera does 60 frames per second at full resolution, all of a sudden 3 frames per second on an SLR looks pathetic. Similarly, I’m unaware of any still camera (aside from maybe weird scientific-engineered stuff) that will take a 1/40,000-second exposure, or any flash that’s capable of running at 7 frames per second.
(That said, I’m having a hard time figuring out when you’d need a 1/40,000-second exposure. I only hit my camera’s 1/2,000-second limit when I’m too lazy to stop the lens down…)
Found a neat experiment here…. Watch this video very carefully and count how many passes the people wearingwhite shirts make. It’s kind of a neat challenge.
Afterwards, leave a comment with your answers. (But no cheating! Watch the video first.)
I mentioned in my previous post in passing about determining which was my “dominant eye,” something I’ve merrily gone 22 years without knowing I had.
Wikipedia refers to the subject as ocular dominance. Essentially, the brain “prefers” one eye over the other. Of course, this is something that ordinarily goes unnoticed, but it becomes quite important in some things, including, apparently, firing a weapon. There are two easy tests to determine your “eyedness,” as Wikipedia strangely lists as an accepted name:
Focus on a distant (6-10 feet is plenty) object. Hold both arms out in front of you, overlapping, and form a golf-ball-sized circle between your thumbs, viewing the image through it. And then, do one of the following:
Slowly pull your hands towards your face, keeping the image centered in the hole. Eventually, your hands end up in front of one eye. That’s your dominant eye.
Rather than pulling your hands back towards you and looking ridiculous, close one at a time. With one eye, you won’t be able to see the object: your hand covers it. (If you can see it through both, the hole through which you’re viewing it is way too big.) The eye you can see the object through is your dominant eye.
Or, with both eyes open and without paying too much attention, point at a distant object. (Don’t look at your finger or you’ll screw things up and have to start over.) Hold your arm steady and close one eye at a time. One finger will be pointing (more or less) right at the thing. The other is pretty far off. The one that’s accurate is your dominant eye.
Of course, I’m left wondering a few things:
Can you accurately use your non-dominant eye? With one eye closed, if you can align the sights of a gun with your target, isn’t it still going to be accurate? I’m trying to ‘test’ this, but doing it with a flashlight isn’t accurate enough, and I don’t have a laser pointer. Further, I feel like a total goofball sitting here squinting with one eye and shining a flashlight at the electrical socket on the other side of the room. To align the flashlight and flashlight, I do shift the flashlight a little, but in both cases, it’s being pointed in the same place; it’s just a question of the angle.
Can you change your dominant eye through practice or the like?
What are the implications in daily life of having your dominant eye be your weaker eye? Uncorrected, I’m something like 20/300 in that eye. Would my perception of scenes be better if my dominant eye was the one with better vision?
The Wikipedia page makes a cursory mention of the two eyes and how they’re processed by the two brain hemispheres. Does this related to being right-brained or left-brained? Is this like the spinning girl and seeing whether she spins right or left?
Although the citizen’s police academy here formally wrapped up a couple weeks ago, they’d set up an appointment at the local police department’s gun range for us. After about 2 hours of reviewing the functioning of a gun, gun safety, and such, they brought us into the range.
Their standard department weapon is the Glock 23, a .40-caliber handgun. A few comments:
They’re very strict about gun safety. (As they should be.) As they talked to us in their classroom, he began with a safety note: all the officers in their room had locked their guns up. The “guns” he used in class were non-functioning demonstration units. He had real ammunition, but, because they would later bring a .40-caliber pistol into the room, had only a single, orange, rubber bullet in the .40-caliber size. The “Range Master” came in later with his unloaded weapon, being very careful to demonstrate that it was unloaded. As he demonstrated proper technique holding the weapon, he was insanely cafeful to never point the weapon, which he had all just witnessed was unloaded, at anyone. When we finally got into the range, they stood right beside us in the booth.
He had us determine our “dominant eye.” I’m right-handed. My right eye has decent vision (maybe 20/40 uncorrected, but 20/15 with contacts), but my left eye is comically bad, 20/300 uncorrected. As he joked, I’m “one of those weirdos” whose dominant eye is different from their handedness (that’s an actual word?!). The way he had us determine it was interesting: hold your arms out and make a hole about the size of a golf ball, and focus on some distant object. And then slowly pull your arms back to you, maintaining the gap you’re looking through. Eventually, your hands end up in front of one of your eyes. That’s your dominant eye. An added wrinkle to the fact that I can’t see out that eye all that well is that, being right-handed, the instinct is to hold the gun towards the right side of your body, and you end up pulling your head over to your right. Of course this must look ridiculous, and the proper thing to do is bring the gun more to your left, keeping your head steady. But as he pointed out, it’s not intuitive.
He said it’s “optically impossible” to keep the rear sight, front sight, and the target all in focus. Thus, even if it weren’t for my poor vision in my left eye, I’d still have ended up doing what I was doing: focusing on the target as I bring the gun up, and then focusing on the gun’s sights, firing at a blob in the distance.
Recoil! It’s pretty common knowledge that the gun will recoil and ‘kick back.’ But until you’ve tried it, it doesn’t do it in the way you imagine. He joked about the stereotypical fear of the gun flying back and hitting you in the face. In actuality, the gun goes more upward; in my case, a little to the left. He mentioned that, with most people who’ve never shot before, their first round will hit dead-center, but then we start trying to “compensate” for the recoil which screws us up. And that’s exactly what I did. I took time to aim each of my five shots perfectly, so my shots are pretty much in a perfect vertical line. Just seeing someone shooting, it’s tempting to think, “What idiots! If you hold the gun a little more steady, you can hold it steady when you fire.” You can’t. You hold the gun nice and firm, and, as soon as you pull the trigger, you’re holding the gun in a totally different place. You see people firing one-handed in movies; I think the gun would fly off your hand if you tried that. In addition to being impossible to prevent the gun from recoiling, he pointed out that it’s actually bad to try to control it: you end up pushing the gun down right before you fire, which throws your accuracy off.
I think shell casings are something that’s viewed like recoil: people know that shell cases get ejected out the side, but don’t give them too much thought. I was firing to the right of someone else. My biggest fear wasn’t that I was holding a loaded firearm with no experience, that I was going to shoot myself in the foot, or that I was going to get my finger sliced as the gun’s slide moved. No, my biggest fear was that one of the red-hot shell casings from the guy next to me was going to hit me. They didn’t, but it’s apparently a fairly common occurrence, hence why they’re big on wearing eye protection. One of the officers we were with was telling us that last time he went to the range, he was wearing a shirt tucked-in but with a loose collar, and ended up getting a shell casing down his shirt, which was apparently not an enjoyable experience. Further, my mental image was that the shell casing would just kind of flop out the side onto the floor. They actually go flying out the side, probably at least six feet.
Anyway, it was kind of fun, but now I see why they spend so much time training: there are so many little things that you need to practice before you’re able to pick a gun up and fire it (with any hopes of hitting your target) in under, say, ten seconds. Which, if you actually need to fire a gun, would probably be the situation.
As an aside, the target was a vaguely human-shaped “blob,” with a very faint “Q” in the middle of it. (They didn’t explain why it had a Q on it.) Part of me wonders if anyone has ever made a T-shirt that just has a very faint “Q” in the center. You’d just have to be careful where you wore it…
I’ve had yosigo in my Flickr contacts list for a while now, as I’m a fan of their work.
Check out this photo, for example. It’s a very simple photo, and any of us could have taken it. He didn’t do a ten-minute exposure with a special lens, and he didn’t use any fancy filters. Contrast hasn’t been bumped up in Photoshop. A five-year old with a camera could take this shot.
And yet, no one else did. While we’re all out there hunting down elaborate shots of obscure subjects in perfect lighting, he’s taking shots like these. Incredibly simple; that seems to be his trademark.
In learning photography, we all learned the Rule of Thirds. Never center something in the photo. Imagine a 3×3 grid, and “center” on one of those. Tell him that. He keeps taking ultra-simplistic shots, and they keep being amazing.
Perhaps most “frustrating” as a photographer, though, is that I feel that it’d be very easy to imitate his work, and yet almost impossible to maintain the “Wow” factor of his photos. If I took a photo of a plate with a piece of bread on it, it’d probably wind up in my “delete” pile.
Periodically I come across deals for computers that are very tempting. I’m not necessarily in the market right away: I’m going to keep my laptop until I’ve been working long enough that I can afford something stellar. It’s silly to “upgrade” a little bit. But every time I see these deals, I think of the various ways I could set things up… My “ideal (but realistic) computer” would actually be a network:
Network infrastructure: Gigabit Ethernet, switched, over Cat6. 10GigE and fiber are cool, but really not worth the cost for a home network.
A server machine. It needn’t be anything too powerful, and could (should) be something that doesn’t use a ton of electricity. The machine would run Linux and serve multiple rolls:
Fileserver. It’d have a handful (4-6?) of 500GB disks, running RAID. While performance is important, it’s important to me that this thing be very ‘safe’ and not lose data. (Actually, in a very ideal setup, there’d be two fileservers for maximum redundancy, but my goal with this setup is to be reasonable. What interests me, though, is that I think it’d be possible to use an uncommon but awesome network file system like Coda or AFS, but also have some network shares on top of that service that ‘look normal,’ so Windows could just merrily connect to an M: drive or whatnot, merrily oblivious to the fact that the fileserver is actually a network of two machines.) It’s important that the machine have gobs of free space, so that I can merrily rip every CD and DVD I own, save every photo I take, and back up my computers, without every worrying about being almost out of disk space. It’s also important to be hyper-organized here, and have one “share” for music, one “share” for photos I’ve taken, etc.
Internet gateway. It’d act as my router/firewall to the Internet, and also do stuff like DNS caching. It may or may not serve as a caching proxy; I tend to only notice caches when they act up, but then again, it might be quite helpful.
Timeserver. For about $100 you can get a good GPS with PPS (pulse-per-second) output and keep time down to a microsecond. Hook it up to the serial port of this machine, and have your local machine sync to that for unnecessarily accurate time. (Actually, it looks like you can do PTP in software with reasonable accuracy?)
Asterisk machine, potentially taking in an analog phone line and also VoIP services, and giving me a nice IP-based system to use, blending them all so it’s transparent how they’re coming in. It would also do stuff like voicemail, call routing/forwarding, etc. For added fun, it could be made to do faxes: receive them and save them as a PDF, and act as a “printer” for outgoing faxes. The code’s there to do this already.
Printserver. If you have multiple machines, it’s best to hang your printer(s) off of an always-on server. It could speak CUPS or the like to Linux, and simultaneously share the printer for Windows hosts.
MythTV backend? But most likely not; I’d prefer to offload that to a more powerful machine, rather than bogging down a server.
Primary desktop. Surprisingly, a quad-core system, 4 GB of RAM, and a 24″ LCD can be had for around $1,000 these days. That’s all I need in a system. I have my Logitech G15, which is all the keyboard I need. My concern is with what to run… These days I make use of Windows and Linux pretty heavily. I think virtualization will be mature enough by the time I’m actually going for a setup like this to allow me to get a Linux-based Xen host and run Windows inside of a virtual machine with no performance degradation. (This is actually mostly possible already, but as Andrew will attest, Xen can still have some kinks….) The system should have a big monitor. It’d be interesting to put something like an 8GB solid-state drive in it and use that for a super-fast boot, but the jury’s still out on whether it’s worthwhile. (I guess that some places are pushing SSD under some special name to make Windows boot instantly, but the reviews I’ve heard suggest that it gives a nominal improvement at best.)
Secondary desktop. Pay attention for a while to the short bursts of time when you can’t use your computer. The system locks up for a bit, or it’s just unbearably slow while the disks spin up and get a massive file, or you have to reboot, or you’re playing a full-screen game and die and wait 15 seconds to respawn, or….. In this “ideal setup,” I’d have a second machine. It needn’t be anything special; in fact, it could be the cheapest machine possible. It’d basically run Firefox, AIM/IRC, Picasa (off of the network fileserver), iTunes, and the like. For the sake of completeness, it should probably run whatever the other system doesn’t, out of Linux, XP, and Vista.
I’m actually not entirely sure how finding these videos began, but some shocking videos for your enjoyment:
“Crazy man throws a wire on 110 kV power line” is about as accurate a title as they come. (Highly, highly not recommended!) It’s essentially the same deal as a lightning strike: one end of the wire is connected to ground, and when the wire makes contact with the 110,000V power lines, it shorts to ground.
This one is even more absurd? Someone provides a translation of the Russian: they’re 500kV lines, and some idiots throw barbed wire (?!) onto the lines. You can’t see them throwing the wire, though, so there’s just a tremendous explosion as 500kV rushes to ground before, most likely, vaporizing the wire.
is really bizarre to me. One description says they’re using “splicing technology,” and another explains that they’re “strengthening the lines.” Neither really gave any explanation to why there’d suddenly be a tremendous explosion and plumes of smoke from all of the insulators. It looks like they sent enough voltage on the lines to jump across the massive insulator. (Which is like a six-foot chunk of porcelain, chosen because it’s ridiculously non-conductive.) Rusty gave a good explanation: it seems that they’ve applied something-or-other on the lines, and are essentially “flash-welding” it on.
Substations often have “air break disconnects,” which are essentially a big, metal, mechanical arm that they can “open” to keep electricity from flowing. The design wasn’t meant to to switch “hot” loads, though. Here’s a video of them opening the disconnect on a 230kV line, which… Well, just watch. (It shorts to another wire after a few seconds.)
Here’s , except it appears that it’s more of a technical failure. It turns into somewhat of an accidental Jacob’s Ladder, before it burns itself out in a fantastic fashion.
This is a neat compilation of various high-voltage “problems.” I actually saw a neat explanation somewhere of what happens in the first video… Something in a high-voltage transformer there shorts to ground, but nothing upstream ever tripped a circuit breaker. The transformer is filled with oil for cooling, before finally it becomes hot enough that it boils and starts spewing ‘steam’ (boiling oil) out its ’emergency’ valves, which makes things much worse, but is actually fortunate in that it blows up the incoming voltage, leaving firefighters with a simple de-energized power grid full of burning oil to deal with. The second is another case of them opening a mechanical “air break” disconnect, apparently in a deliberate test of a 500kV system. Then we see the same clip we saw earlier, and then… The most awesome thing ever. I have absolutely no clue what goes on, but it’s the most awesome fireball ever.
