Posts by rivimey

Sysadmin summoned to explain italics – to a user with at least two degrees

I'll bite...

My answer would be: this is an estimate, so we can consider the bubble to be a sphere.

The part that is soapy water will have a mass that is one sphere's volume minus a very slightly smaller sphere's volume, multiplied by some density.

We can approximate the density to that of water and so calculate that.

Now, is the mass of the soap bubble just the soapy part or does it include the air inside... I would argue it does include the air inside, so add the volume we removed from the soap volume back again, multiplied by the density of air.

so: something like M = ((pi.r³) - (pi.(r-δ)³) ) * λᵣ + (pi.(r-δ)³) ) * λₐ

where:

λₐ = density of saturated air

λᵣ = density of water

r = external radius of bubble

δ = thickness of soap wall

Areas of approximation:

- air pressure will change the volumes a lot

- humidity will change the density of the air

- the bubble is likely not a sphere

- the bubble wall is likely not of consistent thickness

In summary this is likely a very poor approximation.

Whitehall seeks lone C++ coder to keep airport passenger model flying

Re: It's a contract designed for a specific company

Exactly. Nail, can I introduce you to Head!

That program sounds really interesing... is it FOSS? Is there a link to more info (github, whatever?)

Rebuilding VisiCorp's Visi On UI reveals how Apple defined the GUI era

Relation between Lisa and Mac teams: a second go?

This seems like a suitable place to ask: I have always wondered if the Lisa "failed" (and I use that term very losely) because the Mac team came along and used all the exceptional research the Lisa team generated in their first couple of years to have a "second go". So without Lisa the MacIntosh wouldn't have been the thing we know.

I know that the two teams were in some way concurrent, and I know there was rivalry, but I find it very difficult to believe that the two systems came out of the same company with no crosstalk. And I also find it hard to believe that the Mac team would have been able to do what they did without that "first go" of the Lisa, both the hardware and the (frankly amazing for its time) software. The only mistake I saw in this was that the rivalry got too much, and the obvious thing - that the Lisa was the high-end Mac (compatible with it in all ways) - wasn't made to happen by the "powers that be" in Apple. I don't know enough to know what that would have taken to happen but IMO it's what should have happened.

I've been watching Adrian's Digital Basement in his efforts to revive some very dead Lisa systems. The footage is especially interesting in that it shows the hardware was very obviously not cost optimised. A second go with optimisation would have had a very easy first pass!

Russian spy ship theories sink after Orkney blackout traced to wind farm fault

Re: Chain of dependencies

Perhaps have a local UPS (battery) able to run specific things around the house at need? <1Kw units are cheap enough to have several.

CodeRED emergency alert system CodeDEAD after INC ransomware attack

At what point do governments start treating this type of behaviour as criminal in and of itself? So many breaches of data are accompanied with tales of bad practices and lax or no oversight…

Google Cloud suspended customer's account three times, for three different reasons

That will be a good reason to use a 2FA source that is not in itself a single-point-of-failure, such as a phone or dongle.

I use 1Password for this (& other) reasons. Other options are available.

Engineers successfully reboost International Space Station after early Dragon abort

Re: Moonbase building material

From my perspective the best way to make a moon base is on the moon... i.e. in a moon-based factory, with moon (or asteroid-based) materials. AFAIK the minerals present in the moon are very similar to that of Earth. The rocket equation is harsh, and sending all the material up from Earth's surface is IMO impractical.

So what I'm saying is basically we need a moon-based factory(ies) anyway. I keep hoping some of the research into additive manufacture and robotics will make it practical to send a robot or 10 up there on its own to start gathering and refining materials. Once enough have been made we can then send up robots that can use those to make more complex things, and so on.

Hope I'm not creating our Replicator overlords, but how else will we do it?

Voice, vision, pen: Oh dear. Windows boss says Microsoft is again reshaping OS

My big frustration with MS WIndows now is that I have no use for it -- except for specific Steam-available games I would like to play. I have a Win10 machine whose sole purpose is playing the occasional game, and consequently I hardly ever use it (preferring other platforms).

So why are so few (relatively) games available on Linux or MacOS?

The UK’s cartographer maps mission to help people and business

I am in sympathy with those who bemoan the monetisation of OS, a world-leading organisation back in the day. I am also very concerned that while it is easy to buy & keep a paper map to refer to for decades, a digital one moderated by a proprietary app is much more ephemeral. So much research requires or benefits greatly from older maps and I fear we are losing that ability.

On the topic of solar panel coverage I would be interested to see a graph of coverage over the last decade... it seems to me, with installation costs as low as they are, we should be seeing more installations than is apparent to my observation.

And yes, prioritising "shareholder value" has become the bane of our time!

Microsoft eventually realized the world isn't just the Northern Hemisphere

Re: unconscious bias

/pedant Well, some parts of the world get hot and dry, mingled with occasional periods of hot and underwater!

And of course there are always the cold and dry places when you're high enough up!

Datacenter lobby blows a fuse over EU efficiency proposals

The more I see of data security the less I like about where we're heading.

Personally, I would love for the EU (and the UK) to mandate that sensitive data (whether govt or not) is only stored physically within the EU/UK and using companies that do not have a significant (eg >15%) controlling interest from outside that area.

I would like to see datacenters being required to supply a significant amount of energy themselves using solar, wind etc as appropriate. E.g. if you cover the roof of a datacenter in solar panels, cover the car park (if any) likewise. Basically, make a significant effort. Of course in times of excess that can be sold as usual. And energy supply absolutely should set a limit on the size of such places.

I would like to see datacenters required to be external-resource neutral - no mass consumption of water or anything else. I get that this has cooling implications, but in many parts of the world water is or will be a very limited resource and not one that should be squandered (and yes, there are many other poor uses of water).

I realize the above would have the effect of putting a brake on growth but personally feel that is a good thing at this time, not a bad one. It definitely feels like we're in a bubble and bubble's do burst, typically sooner rather than later. Even if this one doesn't, humans are only very slowly getting the hang of the social implications of mass AI and we badly need more time to manage this. Rampant Capitalism in this case is bad IMO.

And finally -- absolutely the UK (presume elsewhere too) needs to up it's game massively on water management and storage, just like it does for power grid management.

Museum digs up Digital Equipment Corporation's dusty digital equipment

Re: amazing documentation too

Back in the late 80s/early 90s I was regularly using several different versions of Unix on different CPUs, all with the same nfs mounted home, so my own scripts and binaries added the right ~/bin/bin.{arch} and ~/bin/bin.{os} tree to path.

I think the most at one time was 5 different CPU arch's and 5 different OSs: HP-UX/68k, HP-UX/HP-PA, SunOS/68k, SunOS&Solaris/SPARC, IRIX/MIPS, AIX/Power. We did also have a DEC Alpha/OSF1(?) but it wasn't something I was using.

Re: Progress

I think originally /bin &/sbin were the commands required to run the system itself while /usr was the stuff users directly invoked, what we would now call apps. The /home tree is much, much later. Even /var wasn't there for ages. /opt was invented (by Sun? or IBM?) as the place to install commercial packages.

The different filesystem thing was at least partly to reduce the risk of a filesystem error... Back then it was not at all uncommon for the bootup fsck (you never skipped them if you were sensible) to find errors even without a power failure or similar. Smaller FS == quicker fsck time and fewer files to restore from backup. The disk full thing was also true as early Unix was not nice to fix if you had 0 blocks free.

As an aside, I still occasionally try to "cat" a directory rather than "ls" it because originally that worked just fine.

National Public Data files for bankruptcy, admits 'hundreds of millions' potentially affected

At what point do people start taking information security seriously?

I used to think that once big companies started losing big money the shoddy practices would cease, but apparently not: here we are. I also think that software developers need to be (more) regulated, such that a developer asked to (or under time pressure) create shoddy or ill-tested code has the backing to say no, in just the same way a civil engineer asked to create an unsafe building must say no. However, I don't see that happening soon either.

What, then? When will people with clout (e.g. business owners, regulators, investors) say enough is enough and do something to stop the plague of crap code and crap security practices? (excuse the french, please :)

Resource burden of electric vehicles set to triple by 2050

Re: The “science” seems off here

The batteries in my solar array have a guaranteed life of 25 years with an assumed charge/discharge cycle every day, and the Q4 car is similar IIRC.

UK vehicle financing tends to be 4 years before buy/return decisions, so likely 12 years before even possibly being scrapped.

I think your numbers are suspect...

Forgetting the history of Unix is coding us into a corner

Re: MacOS Unix server?

Today, MacOS doesn't but the article noted that the Unix server was in the days of NeXT, not modern macOS.

Re: Fork

The special bit about vfork was that it deferred the allocation of physical address space to the new process and use CoW semantics to optimise future page allocations. Consequently, using vfork made much better use of memory for some use-cases because only memory that had to be allocated was allocated.

Both fork and vfork provided the process with the appearance of a new address space. Fork did so from the get-go, creating a physical copy of the original process' data and code, VFork simulated this using the MMU.

In both cases, while the new process could read the old process' data the moment either process wrote to a page the address space diverged.

The main benefit of vfork within Unix at the time was that in most cases a fork was followed almost immediately with an exec, which replaces all code & data with the new program, leaving only the process table (file descriptors and so on). Consequently old-fork was very wasteful, and vfork was used whenever possible. ISTR some instances where vfork semantics were not sufficiently similar, hence retaining both calls, but forget what those were.

German budget woes threaten chip fab funding for Intel and TSMC

Re: Neither settlements are secured

"the Americans and many Brits who are mentally stuck in that socialist/communist swamp."

From where I sit, *some* Brits are stuck in that swamp, many others are 100% in favour of the social/human model. The Brits in the swamp are generally fully signed up to the capitalist model.

UK Online Safety Bill to become law – and encryption busting clause is still there

Re: Why?

Still a spoiled ballot is nearly the same thing as not voting and is ignored by our FTTP, much as I would wish otherwise. While other forms of protest will take more effort they will be far more effective.

Re: A chance for the new king to show what he's made of?

The ability of the King to actually refuse to sign a bill into law is very limited indeed, mostly by convention but also currently the monarchy is relatively weak and there are enough people in the media who would take extreme umbrage.

Micro molten salt reactor can fit on a truck, power 1k homes. When it's built

Re: Missing the point ?

As others have said, there's real benefit to multiple smaller reactors rather than pne massive one. Though I do wonder whether the unit size might be somewhat larger than is mentioned in the article.

Re: As a serious thought...

My understanding is the reactor is not pressurized so nom not high pressures.

When management went nuclear on an innocent software engineer

Re: nice story

For "clicker" substitute "clinker", which is a congealed residue from burning coal that contains more impurities, like sodium, potassium and calcium. It typically forms sponge-like lumps that can have sharp edges when cool. As far as I know, such clinker is no more toxic than the coal it came from, and may be less so.

Fly Ash is quite different, resulting from the burning of crushed coal. Coal is crushed to enable more complete burning, but the residue of this is typically a very fine ash that can cause significant health issues when breathed in, and can form dangerous slurries if wet. The ash, like clinker, forms with sharp edges but because it starts so small the individual particles are small enough to do real damage in the air and in water, being very abrasive. Properly disposing of Fly Ash is very necessary.

As for radioactivity - well Carbon has several common isotopes anc the process of burning will often result in some localised concentrates forming. It is not significantly more dangerous than being in an area with granite bedrock.

'Sharp' chip inventory correction looms on horizon, warns investment banker

Re: This report doesn't seem to reflect the real world...

If you're going to redesign a module to use a new part, why would you not buy sufficient quantity of that to produce a batch at the time you decide on the new part, rather than wait N weeks till you've done the design work? In former days, waiting would make sense, but now it definitely doesn't!

The power of Bill compels you: A server room possessed by a Microsoft-hating, Linux-loving Demon

Re: Memory problems

Back then it was "well known" that the Linux kernel used the available memory much more thoroughly than Windows did; I am unsure of the exact cause but I believed then that Linux would proactively buffer files and use swap processes more aggressively.

The result was frequently to discover bad memory fairly quickly with Linux (usually via segfault) while with Windows it would only show up as a BSOD every so often, which had so many other causes it was considered unremarkable.

The standard answer at the time was to "run memtest86" (later memtest86+) to discover which bank was faulty.

David May, parallel processing pioneer

Transputer Sonar and other heroes...

I did stuff on transputers doing sonar processing as well, while I was at GEC. 4K point FFTs calculated, stored and displayed in real time when the PCs of the time struggled to do 256 point.

I still cannot get over people who say you can't program in parallel: what have the hardware engineers been doing for the last 50 years. What they actually mean is that the way people go about programing at the moment makes it very difficult... but that way is not the only way.

I was hoping the article would mention another of the heroes: Prof Peter Welch, who has backed CSP and Occam for as long as they've been around. Working from his base at Kent University he has pushed message passing and the CSP way to over generations of students from Europe and beyond.

And finally, others have mentioned the transterpreter, but there's also other projects: see www.wotug.org for more details!