sleep is good

“We’ll Fill This Space, but First a Nap”:

posted at 9:40 am on Wednesday, December 03, 2008 in Links, Science and Technology | Comments Off on sleep is good

you can always count on gravity

“Evidence-based Medicine”: sounds like a good thing, until you realize that sometimes collecting the data required causes more problems than it solves. These guys took this argument to an extreme:

“Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials”:

bq. Conclusions As with many interventions intended to prevent ill health, the effectiveness of parachutes has not been subjected to rigorous evaluation by using randomised controlled trials. Advocates of evidence based medicine have criticised the adoption of interventions evaluated by using only observational data. We think that everyone might benefit if the most radical protagonists of evidence based medicine organised and participated in a double blind, randomised, placebo controlled, crossover trial of the parachute.

I’m sure they’ll get _lots_ of volunteers for the study… :-)

posted at 7:25 pm on Wednesday, September 03, 2008 in Health, Humour, Links, Science and Technology | Comments (2)
  1. Bob says:

    That article is brilliant! A bit over the top and stretched the analogy to breaking point but does make a valid point.

  2. chk says:

    Hey! you read my weblog! cool! :-)


I’ve been a big fan of computer automation for as long as I’ve been computing. Computers are partcularly well suited for repetitive, mundane tasks. I used to have a system set up at Alias, based on “track”:, that would automatically keep all of the system software and configuration files up-to-date, long before HP Software bought Radia :-). My PVR is probably my current ultimate example; it automatically downloads TV listings from the source, searches those listings for my favourite shows, resolves conflicts, etc.; all without my input!

Anyway, it always surprises me when I power on an infrastructure server, and the LDAP server or Perforce server or whatever isn’t configured to start automatically! I mean really; who runs around manually starting essential services after a power outage? I thought we stopped doing that in the 1970s…

(We had to power down our labs over the weekend, because the A/C cooling tower on the roof was being refurbished. It took me all day today to get everything running properly again…)

posted at 5:35 pm on Tuesday, October 09, 2007 in Programming, Science and Technology | Comments Off on automation

MythTV PVR-250 settings

For posterity, the resolutions and bitrates I’m now using for recording shows with the PVR-250 on my MythTV box. The “Low Quality” setting is definitely degraded, but watchable; probably because of the reduced resolution more than the reduced bitrate. The “High Quality” setting looks to be good enough for DVD transfers. “Default” produces files that are about 1.5G/hour (my old settings were producing 2.2G/hour, so this will let me record more stuff). I may change them some more, of course…

| *profile* | *resolution* | *bitrate* (avg/max) | *audio sample* | *audio bitrate* |
| Default | 720×480 | 4000/5000 | 48K | 224K |
| High Quality | 720×480 | 6000/6500 | 48K | 384K |
| Low Quality | 320×480 | 2000/2200 | 32K | 192K |
| Default | 720×480 | 4000/5000 | 48K | 224K |
| Old Default | 480×480 | 4500/6000 | 32K | 320K |

I’ve read that the audio settings don’t make any difference with the PVR-250, only the “master” bitrate. Whatever :)

posted at 10:48 am on Sunday, September 09, 2007 in Personal, Science and Technology | Comments (1)
  1. Reid says:

    Given current CPU speed, is transcoding to DivX or something feasible? That would reduce recording disk usage to about 350 MB/hr.

mythtv upgrade

“zap2it”: decided to get out of the free TV listings business (and I’d like to thank them for maintaining free listings for as long as they did!). There’s a replacement, subscription-based service called for MythTV users “Schedules Direct”:, but converting to it requires some database changes, which essentially meant “upgrade!”. So I did; to “KnoppMyth R5F1”:

This was a major upgrade; kernel 2.4 to 2.6, and MythTV from 0.16 to 0.20, so I was expecting trouble. I made a complete disk2disk copy of my PVRs harddrive, and then ran the KnoppMyth backup utilities also.

As it turns out, KnoppMyth is suprisingly easy to upgrade. All of my important settings were copied over intact, and the box did sort of work after the reboots. However, I had to do a number of things manually:

* convert my tv listings source from zap2it to schedulesdirect. Unfortunately, this required re-building MythTV from source, which took all day.
* Recompile the kernel without the vesafb driver (which I remembered thanks to my old posting: “PVR 250 and MythTV”:
* get my Matrox G400 tv-out working, which was basically copy over my old scripts that would sync the framebuffers and adjust the video output
* fix the audio volumes, again
* rebuild the lirc modules, since the kernel source I grabbed from didn’t have these modules already

That was about it. It dig take all day (kernel and myth rebuilds are slow on a PIII-933), but the box seems to be working ok; playback of TV and DivX works, I can record TV shows, and (the reason for the upgrade!) I have TV listings again…

One issue: the console is totally useless until X starts; something is setting the framebuffer to a very strange mode. That’s a problem for another day…

posted at 9:30 pm on Saturday, September 08, 2007 in Personal, Science and Technology | Comments Off on mythtv upgrade

house of the future

The house of the future: complete computer control.

bq. The House of the Future: Complete Computer Control

bq. As Don Sheppard punches his special code into the electronic keypad at the entryway, a monotone computer voice says, “Welcome-home-Don-come-rightin.’ The front door then glides open.

This is from a 1983 issue of Creative Computing. It amuses me that the “House of the Future” articles haven’t changed all that much since then. The technology has improved (“Insteon”: by “SmartLabs”: is pretty cool) but it’s still to expensive (and too geeky) for the average home buyer. Because retrofits are so hard (and labour intensive == expensive), this stuff is best installed by the homebuilders, but there’s no demand…

posted at 9:38 am on Friday, February 16, 2007 in Links, Science and Technology | Comments Off on house of the future

young children understand irony

From BPS RESEARCH DIGEST: Do young children understand irony?

bq. Some children as young as six already understand the idea that people make sarcastic remarks, saying one thing but meaning another, according to psychologists Penny Pexman and Melanie Glenwright.

bq. The children found ironic criticisms – such as “that was great play” – easier to understand than ironic compliments. A grasp of the speaker’s true belief emerged first, then an understanding of the speaker’s attitude and intention to tease tended to emerge together, usually in the older children.

My kids are already experimenting with dishing out sarcasm…

posted at 11:55 am on Monday, January 29, 2007 in Personal, Science and Technology | Comments (1)
  1. Conrad says:

    Yeah, A.’s already got the hang of sarcasm. Comes by it very naturally. S.’s got a way to go, but she’s already got the teenage exasperated/demanding routine down pat.

nuke your sponges

you have nothing to lose but your germs!

‘Waving’ Goodbye to a Kitchen Hazard

bq. A team of University of Florida Engineering researchers have come to the conclusion that microwaving plastic scrubbers and kitchen sponges on full power can destroy practically 100% of the bacteria and viruses, parasites or spores collected on them.

(via “diane duane”:

posted at 10:57 am on Wednesday, January 24, 2007 in Links, Science and Technology | Comments (1)
  1. Nita says:

    I remember that from when I was working full time in food industry as something well known. I also remember seeing something on one of the Food Network shows about 2 years ago about how to properly disinfect kitchen sponges/scrubbers, that basically said “Nuke the heck out of them.”

    I wonder when the original study did come out.

map of the internet

The map itself is cool, but so is the method used to create it; check it out!

xkcd – map of the internet

posted at 9:32 am on Wednesday, December 13, 2006 in Links, Science and Technology | Comments Off on map of the internet

earth observatory – United States Population Density

EO Newsroom: New Images – United States Population Density

This image also has Canadian population density information on it. It’s a very cool looking visualization; check it out.

posted at 12:05 pm on Friday, October 27, 2006 in Links, Science and Technology | Comments (1)
  1. Irving Reid says:

    Harrumph. I clicked on the “Subscribe to Earth Observatory” link, and was offered something other than an RSS feed. I guess I’ll just have to rely on Harald to blog the good bits.

going up?

Apparently it will be 12 years, 74 days until we have a functioning “Space Elevator”: Once it’s economical to get to earth orbit, any number of things are possible!

posted at 5:28 pm on Monday, January 30, 2006 in Current Events, Science and Technology | Comments (3)
  1. Brian says:

    Thanks for noticing the countdown clock. I hope the signifigance of the date didn’t escape you ..

    It’s both the neatest thing about, and the bane of, the job at Liftport. We’ve got a firm deadline, great. And a ton of work in front of us. This will not happen but some days I do wish D.D. Harriman could stop by open up his bank account ..

  2. Harald Koch says:

    I wasn’t sure, because the 2018 wasn’t exactly 50 or 60 years later, but checking “the forums”: confirmed my original guess…

  3. Brian says:

    Michael picked the year based on the projected work to be done, but the date was done for the reason noted. That would make an awesome Yuri’s Night Party …

more on car seats

Since I mentioned it last week, I should also mention documentation *for* child restraint use. The news page references a recent paper proving that child booster seats are 59% safer than seatbelts alone…

Keeping kids safe during car crashes: every child a safe ride | Partners for Child Passenger Safety – Children’s Hospital of Philadelphia

I guess as a parent the bottom line is: for $80, why take chances?

posted at 8:42 pm on Monday, July 25, 2005 in Current Events, Health, Links, Science and Technology | Comments Off on more on car seats

car seats vs. seatbelts

So it may not be as cut and dried as everyone thinks; car seats (over age 2) may not actually make any difference. Good luck finding a politician who is _against_ car seat and booster seat legislation, though; that would be political suicide. Proving once again that government often doesn’t work in our best interests? (There have been other examples of dumb gov’t safety laws recently, based on zero _real_ deaths or injuries; I’ll see if I can dig some of them out of my memory).

The Seat-Belt Solution – New York Times

bq. Perhaps the single most compelling statistic about car seats in the NHTSA manual was this one: ”They are 54 percent effective in reducing deaths for children ages 1 to 4 in passenger cars.”

bq. But 54 percent effective compared with what? The answer, it turns out, is this: Compared with a child’s riding completely unrestrained. There is another mode of restraint, meanwhile, that doesn’t cost $200 or require a four-day course to master: seat belts.

bq. Even a quick look at the FARS data reveals a striking result: among children 2 and older, the death rate is no lower for those traveling in any kind of car seat than for those wearing seat belts. There are many reasons, of course, that this raw data might be misleading. Perhaps kids in car seats are, on average, in worse wrecks. Or maybe their parents drive smaller cars, which might provide less protection.

bq. But no matter what you control for in the FARS data, the results don’t change. In recent crashes and old ones, in big vehicles and small, in one-car crashes and multiple-vehicle crashes, there is no evidence that car seats do a better job than seat belts in saving the lives of children older than 2. (In certain kinds of crashes — rear-enders, for instance — car seats actually perform worse.) The real answer to why child auto fatalities have been falling seems to be that more and more children are restrained in some way. Many of them happen to be restrained in car seats, since that is what the government mandates, but if the government instead mandated proper seat-belt use for children, they would likely do just as well / without the layers of expense, regulation and anxiety associated with car seats.

Followup material can be found at “Freakonomics”:

posted at 8:41 pm on Tuesday, July 12, 2005 in Current Events, Health, Links, Science and Technology | Comments (4)
  1. Heather says:

    As a certified child restraint technician I am offended by your comments but at the same time I understand what u mean. First off if someone knows what they are doing it only takes a second to teach how to use the child seat properly. And the price of seats are outragious yes, that is why I work on donations so that I can buy them at discount and I sell them for even less then I pay for them. If you need help or know anyone who does they can email me at please try not to down carseats they save lives. The only reason they only reduce is because there is no way to stop car crashes from happening unless you just dont drive.

  2. Harald Koch says:

    First of all, we’re talking about child seats and booster seats, not *infant* seats (as you mention on your weblog). Second, it appears you didn’t read “more on car seats”: , or you would have been less offended, I think.

    It’s true that statistical data is often biased; see “How to Understand Statistics”: for a discussion. It’s also extremely difficult to be unemotional about this particular subject. My emotional response is “for $80, why take chances?”; my seven year old has two booster seats, one in each car.

    But I do trust that Steven Levitt has actually done his homework on this one. We cannot for sure explain *why* the statistics are as they are, but we cannot dispute the numbers themselves…

  3. Mike Hickman says:

    AS a child restraint TECH info like you are printing and saying does not help us who are tring to keep kids safe. There are a lot of programs that sell low cost car seats also the program that i’m has free car seats for parant’s who can’t afford them.

  4. Harald Koch says:

    You’re a little late to the discussion, Mike. More uselessly, you haven’t actually argued for or against any of the data.

    I know “TECH”s aren’t scientists, but you’re still in a better position than your average joe to at least attempt to argue for or against.

Stay away from the pizza…

Apparently, “American Pizza Boxes are Teflon coated”:

posted at 8:32 pm on Saturday, July 02, 2005 in Health, Links, Science and Technology | Comments Off on Stay away from the pizza…

Why does the shower curtain blow up and in instead of down and out?

The Straight Dope: Why does the shower curtain blow up and in instead of down and out?

I always thought it was convection; hot air rising out the top of the shower stall sucks the curtain in. But it turns out that cold showers do the same thing, thanks to the Coanda effect.

You learn something new every day :-)

posted at 12:29 pm on Friday, December 24, 2004 in Links, Science and Technology | Comments Off on Why does the shower curtain blow up and in instead of down and out?

Ubuntu Linux

“Ubuntu”: is cool; a Debian-based linux distribution that is more up-to-date than debian-stable (which is getting quite long in the tooth), but not as cutting edge as debian-unstable. I upgraded my hybrid stable / box earlier this week; the upgrade was completely painless, other than some confusion over which modules needed to be loaded at startup. Even my bizarre printer setup (I have a USB- based HP photosmart printer) survived the upgrade!

The new box is current enough to run Azureus without having to jump through hoops to upgrade the graphics libraries to the minumum required by SWT.

I was about to throw in the towel and go back to the RedHat (well, Fedora Core) distribution. I’m glad I didn’t have to :-)

posted at 9:59 pm on Friday, November 19, 2004 in Personal, Science and Technology | Comments Off on Ubuntu Linux

mythtv update

chk@mythtv:~ $ uptime
20:46:42 up 22 days, 11:29, 2 users, load average: 0.69, 0.71, 0.75

I’m very happy with the box so far. It’s nice not having to change VCR tapes all the time; it’s really nice being able to watch one program while taping another. The P933 in combination with the PCR-250 is more than enough horsepower, except when I want to convert a file to XviD for archival purposes, and I can just leave that running overnight…

Our refurbished computer outlet has some nicely configured 1GHz mini-tower PCs for cheap; I think I’ll pick one of those up to build the permanent MythTV box, so that I can have my Windows desktop back. After Andrew’s party, though; I don’t have time before then :-)

(update) I was just over at a friends weblog, and saw a mention of Chef!, a Lenny Henry sitcom from the early ’90s. A couple of clicks later, and I’m recording upcoming episodes!

At this rate, I’m going to need a larger harddrive…

posted at 9:52 pm on Friday, November 19, 2004 in Personal, Science and Technology | Comments (2)
  1. Reid says:

    How does the quality of the recordings rate? Especially in comparison with (a) (S-)VHS tape, and (b) BitTorrent downloads. I would expect it to be about halfway between.

    Of course, if you get one of those HDTV video capture cards, then you would get better than BitTorrent, since they are all only 640 pixels wide. :-)

  2. Harald says:

    I used to tape at LP on my VCR, so the image quality is quite a bit better. TV quality is worse than the XviD’s I’ve downloaded, but they usually start from digital satellite HDTV, as compared to my crappy analog cable signal.

    The convenience is much more of an issue than the quality, for me. Besides, it’s NTSC; how much _worse_ can it get? (grin)

Bluetooth Star Trek Communicator

For the Star Trek Geeks in the crowd:

Gizmodo : Bluetooth Star Trek Communicator

posted at 3:50 pm on Wednesday, November 17, 2004 in Links, Science and Technology, TV | Comments (1)
  1. More for the star trek geeks, Star Trek Barbie is now a bluetooth device that works with your mobile phone.


Best Buy is having a sale on TV-in cards this week, so I stepped up my PVR research. In the process, I discovered that my old Baltimore Dell box has a TV-out capable video card (a G400), and I even have the magic breakout cable! A quick hardware swap and a test, and I’m left with one fewer item to purchase. Of course I still need a large drive, but they’re cheap. And LG DVD burners are on sale, so I should probably pick one up too. And I don’t really want to string network cable, so add a wireless network card. And while I’m at it, I should probably put the DVD burner in an external USB box, so that I can attach it to other machines. And in the meantime, I need a new desktop to replace the one I’m stealing for the PVR…

Technology. Ain’t it fun?

posted at 11:36 pm on Friday, October 22, 2004 in Personal, Science and Technology | Comments Off on PVRs

_now_ they tell me…

“Scientists find coffee really is addictive”:

bq. Don’t be surprised if missing that cup of morning coffee gives you a headache or makes it difficult to concentrate at work. It’s all part of caffeine withdrawal, say Johns Hopkins University researchers who released a study that could result in the official classification of the condition as a mental disorder.

This isn’t news; everyone I know already knows about caffeine withdrawl headaches, and I know of several hospitals that now give patients caffeine either right before or right after surgery, to prevent withdrawl symptoms from interfering with their post-op recovery…

posted at 4:26 pm on Sunday, October 03, 2004 in Science and Technology | Comments Off on _now_ they tell me…
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