Voyager 2 talks in code! Scientists need Enigma Machine to decode science
data!
Voyager 2 is sending back garbled data. The current hypothesis is that a bit has been flipped somewhere in its tiny computer memory by a passing cosmic ray. Hopefully its a reversible failure.
I've encountered bit flip errors under more mundane situations - we all have had a PC crash through 'Memory Parity Error' at one time or another.
( I used to have a PC that when overheated would die due to RAM errors ( A 386-SX at ambient temperatures of >30C (In a little shop with no air conditioning )))
However I ran into this problem one day with a cheap ($1 Cdn) calculator.
We were adding up long columns of numbers. My assistant was using the calculator, and I was doing it with a pencil. There were (legal) reasons for getting a accurate answer. I came up with one total, and she got another.
So we did it again.
Again the totals disagreed,but her total also disagreed with her previous
total!
I took the calculator this time, and we tried several more times.
The manual addition came to the same total every time, but it wasn't the same as the calculator offered.
What was happening was that if we added this column:
24
30
55
37
23
--
159
we would get 139 if we entered it as 24 + 30 + 55 + 37 + 23
But if we mentally grouped figures as we worked, to speed things up:
54 + 55 + 60 we would get, say 142
And of course, 24 + 30 + 55 + 60 would get 146.
A pocket calculator has a very small chunk of RAM that is divided into registers. I doubt very much that any kind of parity check is run on them at boot.
These registers are used to store the intermediate values of each calculation.
Somewhere in one of the registers there was a stuck bit ( Chances favor that it was stuck on binary 0 )which served to mutate each value when it was entered into the register. 11111111 (255) would become 11111101 (253), perhaps, 00011000 (24) would stay unchanged, but 00011110 (30) would become 00011100 (28), 00110111(55) would become 00110101 (53), and so on.
If the damaged register was being used for the sum total, then the answer would be wrong by the same amount (in binary) every time, no matter how the parts were added up.
It was sobering to realize I was holding a calculator that appeared to give correct answers , but was wrong. We take those little machine's accuracy for granted.
I regret not keeping the calculator: it was a novelty then, but philosophically the event has stayed with me.
I observed something odd about a month ago, and I can't find anything to verify it.
I try to be a careful observer, and there were witnesses, so I'm not talking about a hallucination or a dream.
I was driving to Moncton from Sussex along the four-lane highway, in the afternoon.
I was the passenger, and my wife was driving. We were just short of Petitcodiac...perhaps a kilometer away from the offramp. The highway is divided by a strip of land about a hundred feet wide, with small trees and shrubs.
An aircraft was flying down the strip of land towards us. It was a white aircraft, driven by a single propeller, with a Tee-tail configuration and no apparent markings or identification numbers.
The skin had the glossy sheen of fiberglass gelcoat.
I can't remember if I could see landing gear or not. There was no windows, and it carried a black
pod on its back. The pod was quite large, perhaps 1/3rd the volume of the fuselage.
It was flying within a hundred feet of the ground. Speed was difficult to judge, as were were traveling at 110km/h towards it, but it didn't seem to approach any faster than traffic in the opposite lane would. I would judge its velocity to be no less than 80 km/h and no more than 130.
It could see its wingtips rock back and forth through a few degrees as it flew - the day was quite gusty.
I have never seen a picture of an RPV like it, but I am quite sure that it was not a small plane. The legality of its actions seem dubious, flying that close and low to the highway and town.
A mystery, all the more irritating in the way I can find nothing to refer to.
I try to be a careful observer, and there were witnesses, so I'm not talking about a hallucination or a dream.
I was driving to Moncton from Sussex along the four-lane highway, in the afternoon.
I was the passenger, and my wife was driving. We were just short of Petitcodiac...perhaps a kilometer away from the offramp. The highway is divided by a strip of land about a hundred feet wide, with small trees and shrubs.
An aircraft was flying down the strip of land towards us. It was a white aircraft, driven by a single propeller, with a Tee-tail configuration and no apparent markings or identification numbers.
The skin had the glossy sheen of fiberglass gelcoat.
I can't remember if I could see landing gear or not. There was no windows, and it carried a black
pod on its back. The pod was quite large, perhaps 1/3rd the volume of the fuselage.
It was flying within a hundred feet of the ground. Speed was difficult to judge, as were were traveling at 110km/h towards it, but it didn't seem to approach any faster than traffic in the opposite lane would. I would judge its velocity to be no less than 80 km/h and no more than 130.
It could see its wingtips rock back and forth through a few degrees as it flew - the day was quite gusty.
I have never seen a picture of an RPV like it, but I am quite sure that it was not a small plane. The legality of its actions seem dubious, flying that close and low to the highway and town.
A mystery, all the more irritating in the way I can find nothing to refer to.
So yeah, needle crystals diminish in thickness when dissolving.
But they increase in length when 'un-dissolving' (or is that 'solving'?)
Subtleties, subtleties, subtleties ... the reaction is reversible, but it does not follow the same path.
Next time I do time lapse, I'm going to include a clock face in the frames to keep track of the flow of time. This one had a frame timing of about 3 seconds, and a total time of 85 seconds. Compressed to 5 seconds, we're looking at 17:1 acceleration.
I've got a small jar of saturated ammonium nitrate solution lying around, and it was casually exposed to -20C temperatures. The result is readily predictable ; a bunch of solute fell out of solution, and the tiny needle crystals at the bottom of the jar became honking big crystals.
I warmed it back up and everything ran backwards. It takes about twenty minutes to chill the solution down enough for the crystals to grow about 20X in length, so it occurred to me to shoot before and after pixs.
Then I thought about setting up a time lapse sequence. Among the problems of lighting and pose (still not yet settled), I wondered about keeping the camera warm and the bottle unfogged.
Inspiration strikes:
Oh wait, I don't need to chill the bottle, I can just let it warm up and reverse the sequence of photos. The video of crystals dissolving is the same as crystal growing.
Or is it? The crystals are needle-shaped, which implies that there is preferred points of growth, whereas dissolution should occur over the entire surface simultaneously, causing the crystal to get thinner faster than it gets shorter.
I am delighted by the question, and intend to test it.
I warmed it back up and everything ran backwards. It takes about twenty minutes to chill the solution down enough for the crystals to grow about 20X in length, so it occurred to me to shoot before and after pixs.
Then I thought about setting up a time lapse sequence. Among the problems of lighting and pose (still not yet settled), I wondered about keeping the camera warm and the bottle unfogged.
Inspiration strikes:
Oh wait, I don't need to chill the bottle, I can just let it warm up and reverse the sequence of photos. The video of crystals dissolving is the same as crystal growing.
Or is it? The crystals are needle-shaped, which implies that there is preferred points of growth, whereas dissolution should occur over the entire surface simultaneously, causing the crystal to get thinner faster than it gets shorter.
I am delighted by the question, and intend to test it.
I suppose am old enough now to be nostalgic.
I had a Castle Grayskull playset once, and its the only toy I regret losing.
Used a real mix of action figures with it - I think I probably owned more She-Ra and GI Joe figures than Masters of The Universe.
So maybe thats why my imagination is filled with brooding titanic fortifications, and wicked brunettes.
You know, people talk about She-Ra being a really empowering character for young girls, but I don't think any have remarked upon the roles of Evil Lyn, Cat-Ra and Teela on young men's minds. Powerful, beautiful women without being 'Barbified' or butch.
I had a Castle Grayskull playset once, and its the only toy I regret losing.
Used a real mix of action figures with it - I think I probably owned more She-Ra and GI Joe figures than Masters of The Universe.
So maybe thats why my imagination is filled with brooding titanic fortifications, and wicked brunettes.
You know, people talk about She-Ra being a really empowering character for young girls, but I don't think any have remarked upon the roles of Evil Lyn, Cat-Ra and Teela on young men's minds. Powerful, beautiful women without being 'Barbified' or butch.
In the last three weeks, I've encountered three different PCs that have all died the same death: Crusty Brown Goo Release.
There is nothing wrong with the chipsets - all three rendered useless by capacitor failure.
Its a bitch soldering in replacement caps.
They are all PIIIs or better - in fact, the last five years, I've probably seen ten or eleven systems dead from this.
Its stupid that it should fail that way.
I have Pentium 100's that have run for over 15 years without a problem. The sysadmin monitor processor for RenegadeMime's Epicentre cluster was a 486 SX, and at 19 years of age was cycled on and off every six minutes for months on end.
Without problem.
Of course, everyone knows that this is stupid and wasteful and irritating and yada yada yada.
It was while I was waiting for the soldering iron to heat that I remembered something, a paragraph from T.J.Bass's incomparable Godwhale:
'...neck and shoulder circuits were bright and shiny, winking back at him with silvery beads and wires. The neural web inside the skull resembled a dusty cobweb - soot. He pulled down the viewer and attached it to his forehead. Blowing carefully with his nitrogen gun, he checked each chip.
"Here it is! Another of those damned Hive chips exploded." he pulled over his forehead brace and leaned into it as he made the microcuts. "I don't know if its worth it. I seem to spend more time putting these in and taking them out then you do using them." '
The Hive's high tech products tended to fail after a short service period, often by the growth of single-crystal whiskers that ended up shorting out the chips. Here I have expensive and complex circuits dying because they could not use a decent quality electrolytic capacitor.
This is ridiculous : electrolytic capacitors should have a service life of decades. Not a couple of years.
RenegadeMime wants to point out that he used a 486SX for the process monitor because he had one lying around and without the co-processor it wasn't fast enough to bother using in the Epicentre's processing cluster;and that he used it for so long because it worked great and there was no need to tear it out.
So There.
There is nothing wrong with the chipsets - all three rendered useless by capacitor failure.
Its a bitch soldering in replacement caps.
They are all PIIIs or better - in fact, the last five years, I've probably seen ten or eleven systems dead from this.
Its stupid that it should fail that way.
I have Pentium 100's that have run for over 15 years without a problem. The sysadmin monitor processor for RenegadeMime's Epicentre cluster was a 486 SX, and at 19 years of age was cycled on and off every six minutes for months on end.
Without problem.
Of course, everyone knows that this is stupid and wasteful and irritating and yada yada yada.
It was while I was waiting for the soldering iron to heat that I remembered something, a paragraph from T.J.Bass's incomparable Godwhale:
'...neck and shoulder circuits were bright and shiny, winking back at him with silvery beads and wires. The neural web inside the skull resembled a dusty cobweb - soot. He pulled down the viewer and attached it to his forehead. Blowing carefully with his nitrogen gun, he checked each chip.
"Here it is! Another of those damned Hive chips exploded." he pulled over his forehead brace and leaned into it as he made the microcuts. "I don't know if its worth it. I seem to spend more time putting these in and taking them out then you do using them." '
The Hive's high tech products tended to fail after a short service period, often by the growth of single-crystal whiskers that ended up shorting out the chips. Here I have expensive and complex circuits dying because they could not use a decent quality electrolytic capacitor.
This is ridiculous : electrolytic capacitors should have a service life of decades. Not a couple of years.
RenegadeMime wants to point out that he used a 486SX for the process monitor because he had one lying around and without the co-processor it wasn't fast enough to bother using in the Epicentre's processing cluster;and that he used it for so long because it worked great and there was no need to tear it out.
So There.
I hope this was machine translated:
"In Department of a criminal investigation department of the Ministry of Internal Affairs of Russia, located in Moscow in street Zhitnoj, the safe with operatively-investigatory documents was gone. On the given fact check, and, predictably, is spent guilty will incur corresponding punishment.
Two safes with confidential operatively-investigatory documents of department of a criminal investigation department have thrown out by mistake during carrying out of repair. The safes temporarily exposed in a corridor, stirred to the workers doing repair of a building. They have lowered them in a court yard, and therefrom, having accepted for written off, military men of internal armies who bore unnecessary property from a building, have carried them on item of gathering of scrap metal directly together with classified documents stored them. When documents it were necessary, found out, that boxes are not present. "
"In Department of a criminal investigation department of the Ministry of Internal Affairs of Russia, located in Moscow in street Zhitnoj, the safe with operatively-investigatory documents was gone. On the given fact check, and, predictably, is spent guilty will incur corresponding punishment.
Two safes with confidential operatively-investigatory documents of department of a criminal investigation department have thrown out by mistake during carrying out of repair. The safes temporarily exposed in a corridor, stirred to the workers doing repair of a building. They have lowered them in a court yard, and therefrom, having accepted for written off, military men of internal armies who bore unnecessary property from a building, have carried them on item of gathering of scrap metal directly together with classified documents stored them. When documents it were necessary, found out, that boxes are not present. "
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