Friday 28 February 2020

Flipping (pesky?) bits

On 8 May 2019 Radiolab broached the subject of bit-flips (when a 1 or a 0  becomes a 0 or a 1), while listeners in the UK had the luxury of ignoring the still distant Brexit shenanigans of 31 Octob... sorry, January 2020 (in the vain hope that something would deliver us from the nightmare). So this Radiolab offering didn't air (sorry) on the BBC until February 2020.
<RANT>
And the latest is that unless the EU rolls over by June Boris is going to stamp his little foot and spend 6 months in intensive no deal planning, handing over the reins to the disaster capitalists of the far right.This really is the negotiating tactic of the schoolyard – if not the playgroup.
</RANT>
But about those bit-flips. In the words of the Radiolab blurb
Back in 2003 Belgium was holding a national election. One of their first where the votes would be cast and counted on computers. Thousands of hours of preparation went into making it unhackable. And when the day of the vote came, everything seemed to have gone well. That was, until a cosmic chain of events caused a single bit to flip and called the outcome into question.

Today on Radiolab, we travel from a voting booth in Brussels to the driver's seat of a runaway car in the Carolinas, exploring the massive effects tiny bits of stardust can have on us unwitting humans. 
The programme is worth a listen if you've the time, but I'll cut to the chase. In that Belgian election one of the voting machines gave an impossible result; more votes were cast in favour of one candidate than voters who'd used that machine.

There was a manual recount, and before you could say But I thought the Cold War was  over (it was the Communist candidate who'd had the Putinesque...
<ASIDE silliness ="11">
So that's what the name of that pasta dish means...
 </ASIDE>
...success) the IT people noticed that the difference between the manual result and the digital one was exactly 213 (or, as they said on the programme, 4096).

Not being a natural thinker in binary, but having some experience of the world of bits and bytes, when I heard "4096" I thought  Hang on, that's 4K' ...
<ROUGH_EQUIVALENTS>
A "binary thousand" is, in its approximation to 1000, a bit like a "metric mile" (or 1500 metres); that is, not. But close enough. Since 200 metres is just over a furlong, 1600 metres would be a lot closer.
<CALCULATION>
A metre is 4 inches more than a metreyard, so 9 metres is a yard longer than 9 yards (i.e. 10 yards). So 100 metres is 111 yards and change. People of a certain vintage will know a furlong is 220 yards, and there are 8 furlongs in a mile. So 1600 metres is just over a mile.
</CALCULATION>
But sports commentators still call the 1500 metre race "the metric mile".
</ROUGH_EQUIVALENTS>
What caused the bit to flip was a cosmic ray; and it happens all the time, often in a benign way (causing a glitch that can safely be ignored). Computer engineers know this, and know that there is no hardware "shield" that can save chips from this threat...
<CLOUD_CHAMBER>
Cosmic rays don't care about physical objects standing in the way.  The particles themselves are much too small to be seen directly, but there are several YouTube clips with instructions for making a cloud chamber – which lets you see the trails they leave (on the Radiolab  programme they liken them to the con trails that a jet aircraft leaves behind.)
</CLOUD_CHAMBER>
...Bit-flips happens more at higher altitudes (where the cosmic rays have higher energy); and it takes much less energy to flip bits in modern (miniaturized) chips.

So we're screwed, though not entirely. Where precision is a matter of life or death (say, in an aircraft's electrics) there is a way round the problem: redundancy. A life-or-death component is typically duplicated twice; and output commands (such as raise the nose or cut the engines) are voted on. Only a majority vote triggers action.

But redundancy isn't popular among designers of consumer electronics; who wants a smartphone big enough to house a lot of redundant processors?  Some bit-flips – a majority of them? – are benign, and usually go unnoticed. And, as for the rest, we'll just have to get used to the occasional computer blip (in fact, we already are accustomed to computers that misbehave; we just have to learn not to be so surprised when they do). Or (here's an idea) DO WITHOUT THE  WRETCHED THINGS.

Time I did a bit of prep for this:


Bye for now.

b

Update: 2020.04.30.12:10 – A couple of typo fixes. (Does nobody proof-read these things?)


.




Tuesday 18 February 2020

Quarantine and epicentre

People who know a bit about the formation of languages learn  that they must beware of the Etymological Fallacy, which this Oxford Reference page defines as
The belief that an earlier or the earliest meaning of a word is necessarily the right one. That it is fallacious is illustrated by the fact that orchard once meant a treeless garden, treacle a wild beast, and villain a farm labourer.
The creeping Wikipedi-ization of the modern world has exposed us more and more to this tendency to hold that words must mean what they used to mean, which implies that meanings must never change. Still, a knowledge of where words come from can be fascinating.

The word "quarantine" has had a long history, originally referring to a period of isolation at the time of The Plague (well  one of the waves of  one of them – it was all a bit muddled back them, TBH).

This page dates it (with annoying vagueness – the site is, after all, designed to drum up business for English Language summer schools, so it would be unreasonable to expect much in the way off academic rigour) to "a document from 1377"  though in an  earlier form that set the safeness-from-plague period to thirty days – una trentina. In an earlier post I briefly referred to "quarantine"‘s ship-of-possible-carriers origin, but I didn't place the first use as coined by Venetians trying to keep the plague out of Dubrovnik (as this page does if you care to read it through):
The word “quarantine” has its origins in the devastating plague, the so-called Black Death, which swept across Europe in the 14th century, wiping out around 30% of Europe’s population. It comes from the Venetian dialect form of the Italian words “quaranta giorni”, or “forty days”, in reference to the fact that, in an effort to halt the spread of the plague, ships were put into isolation on nearby islands for a forty-day period before those on board were allowed ashore.  
Source
My ingrained cynicism about the temptations of the Etymological Fallacy doesn't,  however,  prevent me from experiencing a frisson of "innocent merriment" ...
<PC_defence degree="set phasers to stun">
(at the risk of seeming to make light of a notably unfunny situation)
</PC_defence>
... when the Diamond Princess quarantine forced the word back to its roots (with people not  being allowed to leave a ship).

My other concern at the moment is the snowballing over-use of epicentre. Again, I'm not trying to argue that the word can only be used between consenting vulcanologists ...
<spelling_for_dummies>
(and the infernal machine wants me to write "volcanologists", but quod scripsi scripsi)
</spelling_for_dummies>
... but I just feel my lip curling whenever people use a big word just to make them sound serious. What's wrong with centre? What's wrong with focus?...
<digression>
There's that innocent merriment again. Focus, being derived from the word for fire, seems particularly apt when talking about an infection that causes, among other things, fever.
</digression>
...hub..., source ... There are many ways of avoiding epicentre; but it continues on its juggernaut way. This view of its growth in popularity (sadly out of date – the  latest data they've got is from 2008, and in the last twelve years its use can only have grown) comes from Collins:

 Anyway, it's time I got back to note-bashing for  our next concert:

<incidental_observation>
A fellow choir member has asked about "Jesu chare"  in the Pergolesi Buxtehude  – not having found chare in a latin dictionary.  There are two problems with this search. The first is that the phrase is vocative – addressing Jesus. "Dear Jesus" would be, in the nominative (just naming him), Jesus carus. The spelling of that second word points to the second problem. This recalls my "epicentre" rant; one of the mechanisms of language change is hypercorrection (trying to sound important by a misplaced display of "learning"). The introduction of h after c ...
<inline_ps>
I'm not referring to a /h/ sound following the /k/. The hypercorrect change is from /k/ to /χ/ (like the sound at the end of Bach). Trimalchio – that* character in the Satyricon – is (unwittingly) referring to the influence of Greek sounds on Latin. Greek slaves were common in the Roman world,  and there were Greek-speaking enclaves in what we now know as Italy.
</inline_ps> 
...is usually hypercorrect; this is satirized as early as the first century AD in the Satyricon; which has a social-climbing character who is mocked for saying chommodus rather than commodus; Oops, TMI.
</incidental_observation>

Anyway, it's lovely music. Don't miss it.

b

Update: 2020.02.18.15:45 – Added inline PS.

Update: 2020.02.19.12:15 – Added footnote

* Oh what a tangled web we weave
   When first practice to update with an inline PS

That character is mentioned later on. Sorry.

Update: 2020.02.21.10:20 – Corrected the composer; it was Buxtehude


Sunday 9 February 2020

Where's the camera?

The many-BAFTA'd film 1917 features, about halfway through, a dog fight from which I've taken an illicit still showing the moment where my eyebrow jerked up (only one eyebrow – this is cynicism, not surprise).
Moment of untruth?
A flaming wreck is hurtling towards the soldier in the open at... what?  100 mph?...
<guess>
This a guess, but it can't have been doing less – possibly a lot more
</guess>
...and he turns and runs along the exact path of the crash . The plane is obviously disabled, so it isn't going to veer off that path. Presumably he thought he could outrun it – quick on their pins, these Tommies; or maybe he just had a death wish. Maybe, though, he knew the camera was behind his mucker in the barn, and wanted to be sure of creating just the right composition (which wouldn't have resulted if he'd done the sensible thing and run off on a perpendicular from the path of the doomed plane).

Like a film scene I commented on here nearly 6 years ago, what mattered was the visual effect rather than any attempt at verisimilitude.

A not entirely unrelated case ...
<different_though>
(totally different, though; the similarity is only that the director's wishes for a satisfying visual composition were more important than any questions or doubts raised in the mind of the viewer)
</different_though>
...cropped up recently in the last episode of the Wisting series on BBC Four.
<spoiler_alert>
And if you are that way inclined, now's the time to bail out. Exposition of a cinematic cliché follows.
</spoiler_alert>
A lone policeman approaches a suspect 4x4, which conveniently enough has windows lighting the boot (not the ideal vehicle for a psychopathic kidnapper who from time to time uses the boot for purposes of  victim-conveyance),
Then the camera angle changes, so that it is inside looking out, as the policeman goes through a basic kidnapper's starter kit  (duck tape, plastic cable ties..., you know the drill).
At this point I started to wonder what could have been the point of this change. But I didn't have to wait long.

Right on cue, the aforementioned psychopath appears behind the policeman and knocks him out (but doesn't think to use his kidnapper's starter kit, to stop him butting in to the next scene).

There are times when cinematic cliché interferes with the story.

<autobiographical_note>
I'm reminded (irrelevantly of course, as this wasn't the director's fault). In the early 1970s I saw, at the Arts Cinema in Cambridge, Chabrol's Le Boucher. In one scene suspense was being ratcheted up by the images and the soundtrack –  I have no clear memory of the details; I think someone was looking for trouble in a gloomy outhouse. But what broke the tension was not Chabrol's soundtrack (a voice from out of the shadows, as I remember). It was the subtitle ( a case of legendum praecox?)
</autobiographical_note>

But I'm missing the cricket.