Posts by Bill Walker

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1) Message boards : Cafe SETI : Don't know where it should go? Stick it here! Part III (Message 1804250)
Posted 2 days ago by Profile Bill Walker
You guys did notice the radio show this is from? The same show that brought stories like "Saskatchewan government to teach teens how to kiss" and "World's first volunteer run, non-profit McDonalds opens in Manitoba". Don't take them too seriously.

WARNING: Canadian humour may be misleading to others.
2) Message boards : Cafe SETI : State Fairs (Message 1803039)
Posted 8 days ago by Profile Bill Walker
We have town fairs and country fairs here, in a range of sizes. The big ones (like the CNE in Toronto) are probably like your state fairs. My wife and I love the smaller rural fairs. Prizes for best pies and pickles, best handicrafts (my mother-in-law won several knitting awards at her local fair), livestock displays, usually a local car club or antique tractor club display, and lots of good food. Everything from the local ladies auxiliary doing fried chicken and home made corn dogs (not the mass produced crap some places have), to big travelling food trucks with slick new things every year. Deep fried butter, doughnut burgers, etc. They will have a midway with rides and games, but we give those a miss nowadays.
3) Message boards : Cafe SETI : Raccoon Update XXIII - All Are Welcome In The Critter Cafe (Message 1801224)
Posted 18 days ago by Profile Bill Walker
Finally! fire flies in the back yard the last few nights. A few weeks late, but here they are.
4) Message boards : Cafe SETI : The Train Thread 2 (Message 1800640)
Posted 20 days ago by Profile Bill Walker
Now that would be a cool commute.
5) Message boards : Cafe SETI : 78's (Message 1800534)
Posted 21 days ago by Profile Bill Walker
I find it interesting that everybody digs up info about deterioration of digital data when we discuss backups, but they never offer an alternative. I've recently gained access to original paper records dating back to the 1920s in government archives, and some of them are in rough shape. Paper deteriorating and crumbling, ink and pencil fading, etc. Even stuff as recent as the 1950s can be borderline useless. My Kodachrome slides from the 1960s and 1970s are fading.

Nothing is perfect. Any form of record keeping requires regular production of new backups.
6) Message boards : Cafe SETI : The Train Thread 2 (Message 1800246)
Posted 22 days ago by Profile Bill Walker
Just a reminder that not all engines are grey in North America. My daughter used to live about 5 blocks from the Denver yard, a great place for train spotting.

7) Message boards : Cafe SETI : 78's (Message 1799942)
Posted 23 days ago by Profile Bill Walker
Thank you, Bill, for a very thorough explanation. It honestly makes me value my records even more. I have a converter machine from Hammacher Schlemmer that will transfer them to CD, but from what I'm gathering here, that result will not be as durable as an original commercially produced disc.

If the conversions go onto writeable disc, you have about a decade - if you are careful. I have a few of those, burned off records, and I am transferring them all to hard disc. With my regular backup scheme, I'm hoping they will last as long as I do.

I still have just over 300 LPs, with a few new ones bought each month (only because second hand LPs are cheaper than new CDs). I love the sound, but they are prone to mechanical wear. Even on the best record players, you can hear a slight degradation after a few playings. I know a lot of people hate CDs, but they just have different shortcomings compared to LPs, and a lot of us are just used to the LP shortcomings. I'm getting into higher resolution digital formats (24 bit 96 kHz for now) and I think that is the best compromise between playback quality and longevity (again with regular backups).
8) Message boards : Cafe SETI : 78's (Message 1799687)
Posted 24 days ago by Profile Bill Walker

So a commercial CD actually has a braille-like series of binary code imprinted on it?

Not bumps like Braille, but pits. The untouched level area is called a land, pits and lands reflect the laser differently so one is a zero and the other is a one. (Forget which is which). The pits are in a spiral, which can be several miles long if it was unwound. The pits are microscopic.

You start with a thin layer of plastic that gets the pits pressed into the front of them from a metal master. The back is coated with a reflective metal, usually aluminium, then a layer of lacquer (transparent paint) and then the label can be printed on top of that. The other side, with the pits, gets a relatively thick layer of transparent lexan molded onto it. You can scratch and mark this, to some degree, but the pits and lands are untouched unless you get all the way through the lexan. Hence the durability of this type of CD. You just have to make sure the all the layers bond well to each other.

On a standard CD it takes 16 bits to make a single burst of music that is 1/44,000 of a second long. (thats 0.000022727 seconds.) Most modern CD players have some sort of error checking, so if a single pit or land gets read wrong the 16 bit number will fail parity check, and get replaced with the average of the number before and the number after. (More expensive players can have fancier error correction that can handle multiple read errors.) A single substitution like this is not audible. If you scratch or mark the lexan in a curve parallel to the edge of the disc you can screw up multiple numbers one after another, and then the error correction can sound weird, or even lead to skipping or periods of silence.

Fortunately, if you have scratches the lexan is polish-able with something like Brasso. You don't have to polish out the entire scratch, just round off the edges. The sharp corners screw up the laser light and lead to reading errors. Just make sure you get all the fine dust off the disc before you put in your player. I do this quite regularly with second hand CDs and even loaners from the public library. Dish soap in warm water works well for finger prints and other substances on the lexan. As long as the pits and lands are untouched, you can get back all the music.
9) Message boards : Cafe SETI : Raccoon Update XXIII - All Are Welcome In The Critter Cafe (Message 1799682)
Posted 24 days ago by Profile Bill Walker
The wife and I were just commenting that we haven't seen any lightning bugs so far this year, which is not normal. Hopefully this is just natural cycles, and they will return in the future. Chipmunks, on the other hand, have overrun the place this year.
10) Message boards : Cafe SETI : 78's (Message 1799037)
Posted 27 days ago by Profile Bill Walker
A lot depends on how the CD was made and how it is treated. Volume production usually molds the 0s and 1s into a plastic base and then covers that in lexan. If you keep that away from heat and solvents, and don't scratch the lexan too much, it should last a few centuries. If you use dye based writable Cds, which some smaller publishers do, don't expect it to last much more than a decade. Much less, if the dye is exposed to UV, like sunight.

The examples above sound like poor quality control in applying the lexan layer.
11) Message boards : Cafe SETI : 78's (Message 1798959)
Posted 28 days ago by Profile Bill Walker
1 old 78 that I liked was Spike Jones & the City Slickers William Tell Overture.


A classic. I have it on CD, another reason I didn't hang on to the 78s.
12) Message boards : Cafe SETI : The Train Thread 2 (Message 1798556)
Posted 24 Jun 2016 by Profile Bill Walker
Taking a more-awake look at it, it would appear that 7273 can attach to a slug at the front end as well as the rear. Those big cables are not standard.

Makes sense for a yard shifter, especially in this yard. This is the new style Canadian yard, probably 20 miles long and includes several sawmills, refineries, and large loading docks. It is moving heavy loads in all directions.
13) Message boards : Cafe SETI : Transportation Safety 3 (Message 1798553)
Posted 24 Jun 2016 by Profile Bill Walker
I'm thinking you'd need inclinometers.

No. Accelerometers (3 axis) are what are inside a smartphone and it knows up. After all gravity is an acceleration. Remember your general relativity.

But would the accelerometers in a car be sensitive enough to be effective on a slight slope (considering they have to deal with considerable vibration in general operation)?
I guess it would depends how good the software is.

Two other things just came to mind:

GPS map databse which may have altitude information.

How is the software to know there is a curb? Wheels turn a different direction.

Don't count on GPS. It is good to maybe + or - 20 meters. Your moving map looks good because the software clicks you to the nearest road. Watch it when you drive past a shallow Y in the road, it can get tricked and show you on the wrong branch for a few seconds.

Car accelerometers I'm familiar with sense horizontal plane accelerations, for anti-skid braking and such. Nothing showing vertical offset. The parking assist sensors look for other cars, not curbs.
14) Message boards : Cafe SETI : Don't know where it should go? Stick it here! Part III (Message 1798550)
Posted 24 Jun 2016 by Profile Bill Walker
I don't think anyone I know (except the penny pincher who drives a stick for the better gas mileage) uses a parking brake as routine.

I drive manual transmissions because they are more fun to drive.

Me too. Always use the manual parking brake on the manual shift car. Never use it on the automatic SUV that the wife drives. Modern automatic transmission parking brakes are just as reliable and functional as the manual brake. Manual brakes, on some cars, have a problem in this country of parts of the moving mechanism being exposed to ice and snow. End result can be the brake not set when you think it is, or not released when you think it is. The Park setting on the auto transmission is all enclosed, and not subject to weather issues.
15) Message boards : Cafe SETI : Transportation Safety 3 (Message 1798482)
Posted 24 Jun 2016 by Profile Bill Walker

Regarding turning the wheels to the curb, do cars that have automatic parallel parking do that when they finish?

They would need to know if they were facing uphill or downhill, don't think current cars have a sensor for that.
16) Message boards : Cafe SETI : The Train Thread 2 (Message 1798416)
Posted 24 Jun 2016 by Profile Bill Walker
I think you are right David, the one in the middle is a slug, not a calf.
17) Message boards : Cafe SETI : The Train Thread 2 (Message 1798282)
Posted 24 Jun 2016 by Profile Bill Walker
An interesting yard shifter consist from Thunder Bay, two cows and one calf. And another reminder that not all North American trains are grey.

18) Message boards : Cafe SETI : Don't know where it should go? Stick it here! Part III (Message 1797121)
Posted 18 Jun 2016 by Profile Bill Walker
When will people learn NOT to open "phishy" emails????
Companies paid more than $3.1B to fake-CEO email scams

Email scammers, often pretending to be CEOs, have duped businesses into giving away at least $3.1 billion, according to new data from the FBI.

I spent several years supporting the legal department of a major multi-national, and I was amazed at how many times employees fell for mail and e-mail scams. Their job was to process invoices as fast as possible, so if they received something that remotely resembled an invoice they would cut a cheque. No time, and no motivation, to think about it. I put together a half day training course for these people, that we figure saved $10,000 plus in the first year. Most of the scams were a few hundred bucks or less, but they came in daily.
19) Message boards : Cafe SETI : Raccoon Update XXIII - All Are Welcome In The Critter Cafe (Message 1797119)
Posted 18 Jun 2016 by Profile Bill Walker
LSM and I saw a pelican over the river when we were coming back from
Edmonton the other day. There are a lot more hunting birds around this
year. I saw a cardinal a couple of years back, and I was hoping it was
warm enough this year for a repeat showing. It is even better than that,
the cycle won't be complete for another two years so there is lots better
to come in animal numbers alone.

We have had steadily increasing numbers of cardinals in the yard over the last few years. There are at least two nesting pairs this year, and their offspring are starting to show up at the feeders. I read somewhere that the average cardinal never travels more than a few kilometres from where it was born, so it make take some time for them to penetrate into central Alberta.
20) Message boards : Cafe SETI : Transportation Safety 3 (Message 1796749)
Posted 17 Jun 2016 by Profile Bill Walker
From the photo, the incident should have been survivable to any passengers. Train is upright, coach volumes intact, no objects penetrating occupied areas. The alternative might have been to allow the train to drive on into annother occupied train, or an occupied platform, or into structure that would penetrate the coaches. De-railing is probably the lesser of many evils.

The REAL way to prevent this accident is to not drive through red lights.

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