* Posts by AdamT

569 publicly visible posts • joined 7 Sep 2010

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HPE seeks $4B in damages from Autonomy boss Mike Lynch and his ex-CFO

AdamT

Every now and then when this case turns up in the news I like to quote this bit from one of the claim/counter-claim documents in this Autonomy vs. HP spat which seems to say quite a bit about the management of HP:

"Ms Whitman ... repeatedly adopted the management approach of ... playing country music to the meeting instructing the senior executives attending to take the meaning of the country music songs and apply them to their own management methods"

Regrettably there is no information as to which country music songs were played.

Venus has a quasi-moon and it's just been named 'Zoozve' for a sweet reason

AdamT

And if you like this kind of humorous mis-reading then search for Ed Gamble's story of the "Danish Boog" ...

Europe's deepest mine to become Europe's deepest battery

AdamT

Re: BAH

"Black Mirror" got there first! https://www.imdb.com/title/tt2089049/?ref_=ttep_ep2

Sierra Space bursts full-scale inflatable space habitat module

AdamT

snark not needed

I don't get why many of the space company CEOs feel the need to snark about each other's companies?

There is plenty of room up there both near to earth and far away.

None of you can do everything so why not concentrate on what you do well and leave the others to concentrate on what they want to do and can do well?

Ironically the most snarked about "other company" has a CEO who (ignoring a lot of what else he does) is actually quite good at congratulating all the space companies on their respective successes.

Also not a great idea to snark about a company that you may need at some point to get your stuff into orbit...

Nearly 200 Boeing 737 MAX 9 airplanes grounded after door plug flies off mid-flight

AdamT

Re: Door plug flies off mid-flight ö

Ironically, assuming at least that this reddit post is to be believed, the plug door is actually a modified emergency door!

https://www.reddit.com/r/aviation/comments/191llbg/diagram_of_a_boeing_7379_midcabin_door_plug_and/?rdt=51226

And, potentially this is the cause of the incident - that, fundamentally, it _is_ designed to open but that this has been prevented to convert it to a plug and those prevention measures were insufficient...

AdamT

Re: Door plug flies off mid-flight ö

I think the 2 hours is left over from when the data recorder used a magnetic tape loop (of two hours) which just cycled round re-recording continuously. The recording stopped when the power was removed (either by catastrophic event or by being switched off). If I recall correctly, several years ago solid state data recorders were approved and now the recording time is effectively unlimited and therefore set to 25 hours for most of the world - enough time for the longest flight and to remember to turn it off afterwards. So, yes, the US really does need to catch up on this - it's not new technology and it's widely available.

In this case it's not clear what the "correct" thing to do would have been though - ignoring what the actual rules are and whether they followed them - given the two hour limit. Switch it off to retain the recordings of the initial incident but then lose all recording of any further incident while returning/landing/etc. ? Or leave it on so that you are capturing the riskier part of any flight, the landing (which is presumably a bit more risky in this case) but lose the data from the initial incident?

Tricky one.

I'd probably go for the latter on the basis that you survived the first incident and will be able to provide eye-witness accounts and the recorded radio traffic to ATC, and the recorder would then remain operational in case there was a catastrophic event later on during e.g. landing with an unexpected hole in the side...

(but I'm not a pilot nor do I have any relevant qualifications or experience on this!)

Apple sets new 16,000-foot iPhone drop test after 737 fuselage fail

AdamT

Re: Could have been worse

Mythbusters did this one too: https://mythresults.com/episode50

Basically if the angle of the path is such that the bullet is still revolving and pointing forwards then lethality is plausible.

If it is tumbling then, probably not.

Shock horror – and there goes the network neighborhood

AdamT

Indeed - in another aspect of that same job we used shaped fuses that looked a bit like keys. The idea was that the different thickness bits of the fuse would take different amounts of time to blow as the thin bits would have higher resistance and less heat capacity so would melt at a different time to the thicker bits. So they could have different ratings depending on the time that rated current was actually flowing.

Given that they were bits of metal physically about the same size as a key I recall that the ratings were in the sort of 50A to 200A range - so pretty chunky. I never witnessed one blowing though. Presumably that would have been quite loud.

We also had sand-quenched fuses where the glass or ceramic tube is filled with sand so that when the fuse itself explodes it doesn't take out the containing tube too.

Why did we need these things? Well, submarine telecom cables have a very simple power supply. You stick one wire into the ground at your side of the Atlantic and connect the other end to the cable core. You do the opposite at the other end. Then you put enough volts on to get around a 1.5A current flow. "Enough volts" for the Atlantic is around 18,000

So one of the toys we had for testing/developing with was a 12,000V 2A DC power supply. A fairly sizeable beast that was quite scary when you consider what it was capable of. We had lots of safety interlocks around that lab!

AdamT

Re: The last time I heard a loud noise and things were restarting...

But don't plug your laser printer into your UPS!

Unless your UPS is really beefy as the power consumption as the fusor heats up is normally quite chunky and can be upsetting to a UPS of sensitive disposition...

(I know this from RTFM'ing not because I've witnessed anything in particular - honest!)

AdamT

... and if you don't have access to the wires going to/from the fuses (which were all buried neatly in the rack)

AdamT

Yes, you could do that in theory if you measured the voltage across the fuse and knew its resistance.

But in practice that would likely be pretty inaccurate because the fuse resistance is probably quite variable from fuse to fuse.

That is pretty much how a multi-meter works on the 10A setting though: it is a thick piece of wire with two sense wires soldered on to it at each end. The multi-meter will then actually be reading a very small voltage drop between those two wires but will (hopefully) have been calibrated so that variations in the thick wire and exact positioning of the sense wires between devices will be compensated for.

By connecting the meter across the fuse terminals then removing the fuse, the current then goes via the thick wire in the meter until you put the fuse back in.

Fuses are actually pretty inaccurate devices anyway. The perception is that a 10A fuse will run fine at 9.9A but blow at 10.1A but that isn't really true...

AdamT

Working for a submarine telecoms cable manufacturer in university holidays when I was required to get a bit of "shop floor" experience. The company was pretty good about letting me have a week in several different departments which ended up in the "final testing" area of the shore-end equipment - think lots of full height 19" telecoms racks.

I was doing the final tests on the "spare set" for something like TAT-9 (which dates this whole story if you look that up) prior to delivery to BT. Along with various messing around with optical fibres and high speed data testing equipment, etc. the final tests were "how much current does each shelf in the rack draw?". The technique was to grab one of these wheeled stair/ladder things, go up to the top with your multi-meter to where the fuses all were, set it to current mode, put the probes into the terminals on each side of the fuse, hold them with one hand whilst you unscrew the fuse with the other. You can read the current, then screw the fuse back in and write the current down on the test sheet - all of which means you get the normal operating current without anything being turned on/off. You then rinse-and-repeat down the line of fuses at the top of the rack.

The final measurement was supply voltage to the rack. This came from a standard telecoms 48V DC supply (think big pile of lead-acid batteries).

Notably the instructions in the test did _not _ include the helpful advice to set the multi-meter to voltage mode first.

As a multi-meter in current mode is a basically just a thickish piece of wire the resultant spark and clunk from the circuit breaker on the battery pack were quite impressive. Followed by the extensive "rattle" as every relay in the various PSUs clicked off and the descending whines of the many, many fans in _all_ the racks that were currently under test ...

Apparently I went white-as-a-sheet which I suspect did something to dampen the laughter.

Thankfully the foreman scuttled over pretty quickly to put me out of my misery and said something like "Don't worry - it's just the circuit breaker, the racks will be fine. Everyone does this - once. You forgot to set the multi-meter to voltage didn't you?"

Scripted shortcut caused double-click disaster of sysadmin's own making

AdamT

Where I work we have "eLearnings".

That's even worse, isn't it?

It feels worse.

Beta driver turned heads in the hospital

AdamT

Re: Scary Movie

oh yes, the intro on Day of the Triffids (assuming you mean the BBC one, of course) - the music and the visuals - was very haunting...

Chap blew up critical equipment on his first day – but it wasn't his volt

AdamT

Re: Should this be so easy?

Classic shape sorter clip: https://www.youtube.com/watch?v=cUbIkNUFs-4

AdamT

Re: Should this be so easy?

I can't help myself, I'm going to have to be the "well, actually" guy. Sorry!

Those differing connectors is actually a temperature thing not a current thing. The kettle connector has to be different (and has a little notch to enforce this) because the kettle gets hot and the connector could rise above 70 C.

i didn't realise this but there is also a "very hot" version if the temperature might go over 120 C.

But, yes, I do agree that the whole "could be 120V, could be 240V, who knows?" thing is strange...

NASA, DARPA enlist Lockheed to build nuclear-powered spacecraft

AdamT

Apparently (based on a very quick read of Wikipedia!) it is actually the opposite. You want high ISP from a rocket and the ISP is linked to the kinetic energy of each unit of propellent mass. But the KE per molecule of propellent is related only to the temperature. As the KE comes from the thermal energy you are better off with lighter molecules as you get more of them per unit of propellent mass (given that the temperature is usually limited by the materials you can use).

The same is technically true of chemical rockets as well but your "propellent" in this case is the exhaust gas and that is determined by what you burn. So there you have the combined effect of the combinations of chemicals that can generate the necessary thermal energy at the appropriate temperature but ideally burn to produce something with as light molecules as possible.

(shamelessly ripped off from here: https://en.wikipedia.org/wiki/Nuclear_thermal_rocket#Principle_of_operation )

Aliens crash landed on Earth – and Uncle Sam is covering it up, this guy tells Congress

AdamT

Re: Not impossible, just ludicrously unlikely

Dyson Sphere? If I recall correctly, the amount of metal/stuff that you would need to construct a full dyson sphere would likely exceed the available matter from planets/asteroids/etc. in a single "typical" (if there is such a thing) solar system. So to do it properly you might need to mine some other nearby ones.

Of course, in that situation, you are likely to be uninterested in whether those nearby ones actually contain life of any kind - excepting that it may attempt to resist your efforts!

US watchdog grounds SpaceX Starship after that explosion

AdamT

They explained this in the SpaceX livestream.

There won't be pads or ground support equipment on the moon or on mars so they need to get the hang of launching from close to "normal" ground and coping with the dust/gravel/rocks flying around.

Obviously what happens under a super-heavy booster with 33 engines launching in earth's gravity is a bit more extreme to what it would be like under a Starship with 3 or 6 engines launching in the moon's or mars' gravity but, in typical SpaceX style they decided to have a go anyway. Turns out that probably was a step to far.

But also bear in mind that just because the space industry has always done it with flame trenches/water deluges/etc. doesn't provide strong evidence that they are actually necessary. If "the space industry has always done it this way" was used as evidence for everything then SpaceX just wouldn't exist because the space industry was 100% sure that SpaceX's plans for reusability were impossible. And now look where they are - the first test of a system where both the booster and the spaceship are fully re-useable.

SpaceX feels the pressure, scraps first orbital launch of Starship

AdamT

I think perhaps we have all started to get used to SpaceX's amazing successes with their experimental vehicles (and, in the context of rovers - both wheeled and flying - NASA is doing pretty well too!) but they did seem to be trying to highlight on the commentary that there is a sliding scale of "success" on this one that even at 100% still ends up with the entirety of the two vehicles destroyed in the sea!

Goal 1 - shuts down safely and doesn't vaporise the vehicles and the launch site

Goal 2 - gets high enough before vaporising the vehicles to not vaporise the launch site

Goal 3 - gets to separation and then vaporises both the vehicles

Goal 4 - gets to separation and then only one vehicle vaporises ...

... etc., etc.

In spite of the article author's disappointingly ill-informed snark, what SpaceX want most is information/telemetry and they don't always need to "stick the landing" to get what they need. Once they have what they need then they move onto the next thing.

They didn't need any more starship landing tests because, at that point, they decided not to bother with legs any more - they are going to catch it.

They haven't bothered trying to catch it yet because (a) they want to make sure the tiles and heat shielding work at re-entry speeds and (b) they know they can deliver a Falcon 9 to a ship with the necessary precision so they are assuming they can do the same with this (likewise with the booster)

... etc., etc.

If anyone is actually interested in the SpaceX thought processes behind a lot of this then I really do thoroughly recommend the interviews with Musk (and the starbase tours) that Everyday Astronaut did and has on his YouTube channel.

Australia takes its turn to kick TikTok off government kit

AdamT

Am I missing something?

Why is any government supplied device allowing anything to be installed other than the specific work/government required apps? Shouldn't these devices be completely locked down anyway?

Yes, I know that many/most governments have social media accounts (even on TikTok maybe?) in which case, sure, let those people have two devices : one clean and one dirty. And, of course, any personal device they have should be completely separate.

Boffins claim discovery of the first piezoelectric liquid

AdamT

Re: Interesting question

technically they need to get another 4 in after that before they will really deserve that breakfast...

AdamT
Boffin

But why?

If no one knew of (or believed in the existence of) a piezoelectric liquid then why were they randomly putting 1-hexyl-3-methyl imidazolium bis(trifluoromethylsulfonyl) imide in a cylinder, compressing it and measuring its potential difference?!

I'm sure there is more to the story that would be interesting to know.

Even if it is one of those "we were trying something completely different and found this by accident" ones.

(like the discoveries of artificial sweeteners which all seemed to have been discovered by shocking lab cross contamination - in one case so bad that the researchers family complained their dinner at home was too sweet...)

Moon's glass beads contain enough water to support a mission

AdamT

Re: A lot and just a little

"Ball boy" - you still have 4 mins to edit this before the SI Police arrive!

Hint: Kg are the same everywhere...

Boeing Starliner's 1st crewed trip to the ISS delayed again over battery overheating risk

AdamT

Re: Rather them than me

Didn't one or both of the original two assigned retire early already? Although, to be fair, this thing has overrun by so many years that could just be natural passage of time rather than them "nope!"-ing out

The Moon or bust, says NASA, after successful SLS/Orion test flight

AdamT

I think they only have enough of certain hardware (including main engines I believe?) for a fixed number of flights, regardless of whether they are tests or real/crewed.

So there is a lot of pressure for the tests to all pass and to not downgrade a planned crewed mission to un-crewed test.

Opinions may vary on whether this is a good thing or not....

Language, schmanguage: NASA's generative AI builds spaceships

AdamT

Re: the algorithm can sometimes make structures too thin

Ah, I know this one: the back is a beam that is being (mis)used as a column. The evolutionary advantages to being vertical outweighed the problems caused by the mis-use.

I believe there is likewise an affect on our digestive system which should be hanging loosely by itself below the afore-mentioned beam but is in fact now sitting on the pelvis with all the other organs sitting on top...

My favourite "evolution being a bit dumb" is actually the vocal cords. Apparently these used to be the valve that prevented us from choking. i.e. they could seal off the windpipe completely. Many animals still have this and, therefore, cannot choke. But the evolutionary advantage of being able to modulate our grunts to each other was bigger than the problem of occasionally choking to death by drinking "the wrong way".

Romance scam targets security researcher, hilarity ensues

AdamT

Why....

.... are they called "pig butchering scams" ?!

(I'm at work and afraid to google it....)

What's up with IT, Doc? Rabbit hole reveals cause of outage

AdamT

Yes, exactly.

My surprise was that the bite managed to make the Live and Neutral touch together but without at any point letting either of them touch the earth wire or the fox itself - which would have been standing on damp grass ...

AdamT

"Andrew" has form for this

Not just rabbits but Guinea Pigs too: https://www.theregister.com/2020/06/26/on_call/

(and cats: https://www.theregister.com/2020/12/18/on_call/)

AdamT

I had some 240V Christmas lights in the garden one year. A fox chewed on the cable and, oddly, the RCD did not trip but the 3A fuse did blow and there was a reasonable amount of burning of the plastic around the bite zone.

So I guess it got lucky and crushed the conductors together without touching them directly, maybe? Although presumably the spark/flash in its mouth would have been startling.

On the other hand, I don't actually know what "tripping an RCD by touching the live wire" would feel like as I've never had that happen. Does anyone know?

(For the record, I do know what "touching a live wire before the days of RCDs" feels like! Oddly, I would say that it was not as bad as the "dishwasher motor capacitor discharge via the mains plug" shock I once got before that got banned! )

Oh, 07734! Internet Archive debuts vintage calculator emulator

AdamT

Re: [TI & HP] were allowed into college entrance exams and various standardized tests

I thought the lack of Casios in general was a bit odd.

But I actually don't need an emulator for my Casio fx-250 as I still have it. And it still works...

Massive energy storage system goes online in UK

AdamT

Re: Decommissioning?

Yes, I think this was the original Tesla plan. All the batteries that go into cars should end up returned either at end of car life or if the capacity has degraded too much. Then the packs will be stripped to the individual cells which will be tested and anything above 90% (or maybe 80%?) will just go straight into a storage pack - if they are 10-20% physically bigger that is not a big deal especially if you then get the cells basically for free. Then when the storage pack has degraded you ship the cells back one more time and they are physically stripped down to component/goo level and those are reused (where possible) and recycled otherwise. Again the claim was that the reuse percentage should be quite high.

I think that last piece is still under development though. Someone senior at Tesla left a year or so ago to set up/run a company that was specifically doing this.

Time Lords decree an end to leap seconds before risky attempt to reverse time

AdamT
Joke

Re: An idea....

Well, I assume these days that most people watch via streaming so that means it can be timed based on your location!

Similarly, Ed Sheeran ticket timings are based on the location of the venue.

See, it is a genius idea!

(But I'll keep adding the Joke Alert icon because, well, some people just aren't ready for these next-level concepts of time and space!)

AdamT
Joke

An idea....

[repost]

... why don't we do away with timezones altogether? We all (*) have a device that knows _exactly_ where we are so could easily calculate a precise local time for you. Then all we have to do is indicate exactly where the event is due to occur at its local time and then everyone knows exactly when too!

So bus/train timetables would factor in the position of the stop/station and maps route finding would know where you are starting from (and what time it is there) and compare that with the place you are going (and work out what time it is there), etc., etc. ...

There might be a few minor teething problems but I'm sure we could make this work!

It would have a couple of advantages of spreading traffic and power requirements out a bit as depending on which side of the country you are, you would be doing things at a slightly different UTC (or UT1) time compared to the other side.

This is a great idea! What could possibly go wrong?

(*) well, many of us and a rapidly increasing proportion of the human race.

No, working in IT does not mean you can fix anything with a soldering iron

AdamT

Re: Other way round

Reminds me of the time when my company recruited a Japanese technical translator to help us understand various Japanese patents and technical documents. She needed the Japanese version of Win 95 and, as the unofficial team BOFH, I got volunteered to try and get it onto one of our laptops.

What I hadn't realised is that the "language versions" of windows really are "all in" on the language, even in the the setup phase.

It took me several attempts to get it done so she helpfully wrote/drew out all the correct answers to the set up questions for me!

UK politico proposes site for prototype nuclear fusion plant

AdamT

Re: the distance in feet, divided by the time in minutes.

I read an article in one of the early computer mags (in the 80s, so on paper!) where they were satirically bemoaning (a precursor to El Reg perhaps?) how the software specs will always be in the most inconvenient units possible and casually threw out the example of acceleration in furlongs per square fortnight ...

(approximately 0.137 nm/s^2 in case you wondered)

DoE digs up molten salt nuclear reactor tech, taps Los Alamos to lead the way back

AdamT

Re: REstart?

I am wondering no longer. Thank you!

AdamT

Re: REstart?

I appreciate that it is a bit different (in pressure, temperature, toxicity, radioactivity and many other hazardous parameters) but I'd always wondered how wave solder machines heated up their tank of solder given that presumably the pump blades and everything were fully immersed and therefore embedded in the solid solder?

You need to RTFM, but feel free to use your brain too

AdamT

Re: Check you can complete before you start

Ugh. I used to hate these "joke" tests that teachers (and apparently actual serious employers) would do.

It says "_read_" these instructions. Not "_follow_" these instructions.

So, great, I've read them and I now know there is an inconsistency in them that future instructions will contradict previous instructions. But that just means the instructions are bad/stupid. If you do what the "joke" suggests you should do then you followed the instructions out of order - which is wrong. If you follow them in order then you did some things the last instruction told you not to - which is wrong.

Key point then is that the person/company that set the test is wrong or thinks they are a bit clever (and is wrong about that too)

Oblig. XKCD: https://xkcd.com/169/

Rocket Lab to attempt mid-air recovery of descending booster

AdamT

Re: I'll only watch....

If they make a film of this it will sound like a Huey...

BT starts commercial trial of quantum secured London network

AdamT

Not really understanding why "the trick" was to have the keys and the data on the same fibre? The data is secured with standard public key encryption (it says) and, presumably, the keys for that are frequently changed and the exchange of those is done by the clever "quantum" bit. But that should mean that the data can go by any available route?

Perhaps the clever bit is that they already have the "any available route" in the form of fibres provided by OpenReach so being able to fit the quantum bit down that route too is actually quite convenient. Although as the appropriately named "A Non e-mouse" points out, this is actually hop-by-hop so presumable requires lots of physical security around each node...

South Yorkshire to test fiber broadband through water pipes

AdamT

Water proofing will be important

From my days working for a submarine cable manufacturer I recall that keeping water away from the actual fibres is extremely important. The refractive index of water is close enough to glass that it kind of "wicks" the light out. So the cable is filled with some water repellent chemical etc. around the fibres (as well as the cable being waterproof, etc.) and the joints are similarly very well protected.

Obviously any land based outdoor rated or buriable fibre should be similarly protected but it does feel like there is a bit of a difference to then sticking it in a high pressure, high flow water main!

First Light says it's hit nuclear fusion breakthrough with no fancy lasers, magnets

AdamT

Re: So... an idea like the engine a certain L. of Q. invented?

Yes, my first thought too! The Ultimate Internal Combustion Engine.

Nothing changes except the nature of the thing you are trying to make go bang.

Hear us out: Smartphone lidar can test blood, milk

AdamT

Re: Too good to true?

Yes - not sure if the paper is peer reviewed yet but, as you say, enough detail that anyone can have a go at it.

Even if it can't be done practically/commercially with just a phone, a new testing device that only needs a drop rather than a test tube full and can be built with COTS sensors is still quite a breakthrough.

"... a pint?! Why, that's very nearly an armful!"

Volcano 'shredded' submarine cable, vastly complicating repair job

AdamT

Re: I wonder if that cable has to be manufactured first too

Some of these ships can carry 1000's of miles of cable - at least of the thinnest, least armoured stuff that normally makes up the majority of the length. Length considerably reduced as the level of armouring goes up. If I recall correctly, trans-Atlantic links were often done in two main lengths and then perhaps one more short length at each end with the heavily armoured cable.

Having said that, the "Sir Eric"'s CV does suggest that it mostly worked on the shorter length projects, the shore ends and repair missions so perhaps it's not one of the bigger cable ships.

Your memory of 5km or miles is probably a little low but, to be fair, if it was triple armoured cable than actually that could be a per-tank figure. That stuff has a much higher cross sectional area and a reduced bend radius so possibly they wouldn't be able to use all the capacity of the tank either.

AdamT

Re: Submarine cables

This is a nice resource too: https://www.submarinecablemap.com/

AdamT

Re: I wonder if that cable has to be manufactured first too

Physically the cables are likely to be somewhat interchangeable. They may vary in the number and type of fibres, the voltage rating (for power to the repeaters) and the amount of armouring and tensile strength - but broadly I would suspect that there will be some consistency such that a similar cable could be found.

However the repeater/regenerator units are most likely completely custom to that link. Even if they are manufactured based on a standard type they are likely still customised in some way to the individual system. However, the system plans will always call for a certain number of spares to be made and stored.

Source: I used to work for STC Submarine Systems. Although this was a while ago and I guess things could have changed since then...

JPMorgan Chase readies for post-quantum security world

AdamT

Re: Post Quantum Security

Isn't this just another massive scaling up of the trust problem?

i.e. the number of people who actually understand this stuff enough to have a valid opinion on it is vastly smaller than for conventional encryption and the level of trust we will need to have in those people will be higher too.

File suffixes: Who needs them? Well, this guy did

AdamT

Re: Competition time!

To look more like Apple?

Yes, I get that people's opinion on whether being more like Apple is a good or bad thing may vary but, around that time, Apple's look/feel and general user experience (for the non-techy at least) was better/cleaner. Personally it's not my taste but for many (e.g. my mum) picking Apple over Windows was a no-brainer and I think MS wanted to try and get some back.

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