* Posts by John Robson

5178 publicly visible posts • joined 19 May 2008

The Post Office systems scandal demands a critical response

John Robson Silver badge
WTF?

Re: It's still happening

How on earth does anyone think that should even be a function...

Leaving aside how badly written it is.

'foo = bar + ReverseSign(sna)'

OR:

'foo = bar - sna'

John Robson Silver badge

Re: It's still happening

"Which means it's highly likely the managers can't tell which developers are shit or not, even if you showed them sample code."

Which is why everywhere (sane) I've ever worked we've had technical people in the interview process.

Tesla owners in deep freeze discover the cold, hard truth about EVs

John Robson Silver badge

Re: Norway

"Yeah, it is ridiculous that you need an App."

You don't - a tesla driver pulls up to the charging station, plugs in, and then walks off to relieve themselves.

Then they come back, unplug and drive off again.

That's the entire process, the billing is automatic - the car talks to the charger, the relevant account is billed.

Far easier than any liquid fuel station.

If only CCS had that built in as part of the standard (and it clearly has enough, since various chargers/cars now do the same).

John Robson Silver badge

Re: Frozen batteries

"After that, one might want to keep an eye on it to make sure it isn't programmed to start doing bad things."

Wow - the cynic is strong with you...

John Robson Silver badge

Re: Frozen batteries

It'll last just fine. The BMS on basically all modern vehicles is actually reasonably smart about what charge it will allow at what temperatures, and anything reasonably tolerable for a person is also fine for current batteries.

John Robson Silver badge

Re: Frozen batteries

"Lithium-ion batteries have to be pretty warm to fast-charge, over 100F."

Nope - mine fast charges (100kW+) at anything over ~15-18 degrees, which is in the 60s for those using arcane units.

Could it charge faster if it was over 40? Maybe a little, but not much - and the battery temperature does increase noticeably as the charge continues, so it's fairly easy to watch the temperature/soc/charge rate.

John Robson Silver badge

Re: Just very important to not force people out of the working technology.

Regularly used to cycle past all the cars stuck on the icy roads...

Particularly remember overtaking a gritter stuck behind a queue of cars unable to crest the hill, I got about 30 yards further than any of them, then popped a foot down and pushed for about 10 yards before cycling again.

Whilst I've come home to find snow "aero rims", I've never had any sprockets or mudguards clogged with snow.

John Robson Silver badge

Re: Norway

Negative 50 is sufficiently cold that it doesn't matter which temperature scale you use.

The lowest "minimum typical winter low" is Minessota according to https://wisevoter.com/state-rankings/coldest-states/#minnesota

And that's -19C...

https://www.visitnorway.com/plan-your-trip/seasons-climate/winter/#

"The climate varies greatly from region to region in this long country. Along the coast, temperatures usually stay around zero degrees Celsius. Inland, the temperatures are mostly lower and might sink down to 10-20 degrees below zero Celsius. Some places can even experience an bone chilling minus 40 degrees Celsius!"

So whilst Minnesota does have a record low of negative 50, so does Norway (it's 51.4).

By the time you need block heaters... you plug in the EV when you stop, and you probably want a software change to keep the battery conditioned.

You know, do the same "special treatment" for both vehicle types - because at that temperature anything designed for "normal" operating conditions isn't going to fare well.

John Robson Silver badge

Norway

Good thing they never have cold weather in norway - they've got plenty of EVs...

Stripe commuters swap traffic jams for hydrofoil glam

John Robson Silver badge

Re: all with no carbon emissions

They're in SF... so probably solar.

And the transport itself will be without emissions, which is in and of itself an improvement over many other forms of transport.

A 6 seat boat doing one shuttle a day seems mighty inefficient though.

Can solar power be beamed down from space? Yes. Is it commercially viable? Not yet

John Robson Silver badge

Re: Alternative uses

"The collector satellites are going to be in darkness for some period."

Have you considered what that period might be?

Wing, Alphabet's drone delivery unit, designs bigger bird to deliver pasta, faster

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Re: ingredients for dinner - pasta, marinara sauce, parmesan cheese, canned olives and garlic.

"As for waiting a couple of days that's makes zero difference because the thing will still need to be delivered"

But it doesn't have to be a dedicated vehicle... so it can be delivered more efficiently if it's delivered where there is other demand as well...

John Robson Silver badge

Re: ingredients for dinner - pasta, marinara sauce, parmesan cheese, canned olives and garlic.

If they'd talked about medical supplies (as with the rather good drone system in <can't remember the african country>) then they'd get alot more sympathy.

There are occasions when a rapid delivery is needed, but pasta?

Ban on Apple watches with blood oxygen sensors confirmed after failed appeal

John Robson Silver badge
Facepalm

Re: Apple Watch Series 9 and Ultra 2 no longer include the blood oxygen feature.

"For the small percentage of people who need that (asthmatics and the like) if they wanted one they can probably one on eBay. IIRC the patents in question expire "

I just read that as patients expiring... which isn't the same thing *at all*.

I thought you'd gone really dark, really quickly.

BOFH: Nice air conditioning system. Would be a shame if anything happened to it

John Robson Silver badge

Re: Hilarious episode, once more!

" If you enter on the ground floor, you must stay there. You probably can't enter on the other floors, so those are out."

Once had an office building with 9 floors, 7 of which where ground floor... that was a fairly steep hill.

John Robson Silver badge

Re: Tea and coffee

"My secure laptop has something like this already. It doesn't allow PS/2->USB keyboard adapters, so I can't annoy my colleagues with my 1990 built IBM Model M!"

RasPi zero emulating a "supported" USB keyboard, with a USB-PS/2 doodad an option?

Deep Green gets £200M from power supplier to scale waste heat reuse

John Robson Silver badge

Re: The lawyers of thermodynamics would like a look at the contract.

"It allegedly 'saves' £20k a year, and that number has remained strangely constant."

Two possibilities:

- The model is the only thing they can possibly quote, and they don't remodel each time the costs change.

- The contract is "cost -£20k"

John Robson Silver badge

Re: The lawyers of thermodynamics would like a look at the contract.

Since I actually know something about that system... the issue is that they couldn't drill nearly as far as they wanted, so they are scavenging from a far smaller loop, at lower temperature than was expected.

Aiming to keep an open air pool at 30-35 degrees is also just crazy hot.

Electricity is fairly expensive, mostly because the market is set up to make sure that burning gas remains the determination of cost - we'll get away from it soon - but it doesn't matter what the cost is if your visitor numbers drop substantially...

John Robson Silver badge

Re: The lawyers of thermodynamics would like a look at the contract.

"These are council services, and councils are busy dropping like flies, thanks to their 'investments'" chronic underfunding from central government. FTFY

"LED Community Leisure Ltd (LED) is a not-for-profit charitable trust" - i.e. not the council directly.

District heating can use low grade heat, though it's better with slightly higher grade... but again - if you can run your heat pump using the output of a data centre then that's easily scavengable heat to convert into medium grade heat - i.e. a substantial cost saving operationally.

John Robson Silver badge

Re: The lawyers of thermodynamics would like a look at the contract.

I doubt that they'll be paying for the electricity, unless they made a serious mistake and sold a fixed rate contract without buying a fixed rate supply contract.

John Robson Silver badge

Re: The lawyers of thermodynamics would like a look at the contract.

I would expect that it's the data centre that pays for their power - even if that power is actually purchased from the leisure centre rather than the grid directly.

Now if they didn't purchase that electricity efficiently, or if they fixed only one half of that purchase/supply contract, then that could leave the leisure centre in difficulty given recent price rises in fossil fuel supplies.

Of course your article is about 11 months old, since it refers to Friday Feb 24th (must 2023) in the (recent) past tense.

It probably therefore is about coincident with the installation of this system - and indeed it says as much:

"To reduce its energy costs and carbon footprint LED has installed ... a new state-of-the-art heat recovery system that is due to be commissioned imminently."

Need to plug in an EV? BT Group kicks off cabinet update pilot

John Robson Silver badge

Re: From what I can recall ....

As I explicitly said in my last post: "Vimes boots applies"

Just over the bottom end of the market the EV's do exist - and the savings they produce even over just the first year are substantial. Indeed when I got my first EV it was because the alternative (ICE) vehicles would have cost *more* on an annual basis. The only vehicle, large enough to carry a family of four and my wheelchair, which I could afford on motability was an EV - and that was based on petrol at the "then" price of £1.10, not the current £1.45. My electricity cost has actually dropped over that time (specifically off peak was 10p, is now 7.5p).

Last year's stats: just over 12k miles, which would have cost (in my last ICE car) well over £2k, but cost me less than £300 - an 89% saving in the biggest cost of a "cheap" car.

And yes, I know that the motability lease rates are very favourable, but I'm comparing motability to motability.

The second hand market will develop, and develop quickly. But the way to develop it is to change the inputs to the two markets... as ICE is displaced from EV at the "new" end of the market the second hand market will naturally follow.

That's not a metric which is actually in favour of ICE, it's in favour of the bicycle, the bus, heck even a taxi... Very low up front costs, and generally minimal running costs. At some point taxis get expensive, but you can take quite alot of taxis for the cost of running a car...

John Robson Silver badge

Re: From what I can recall ....

"Sadly, not everybody is you."

You would do well to apply that to your own excessive transport "needs".

Not everyone needs to do twelve hundred miles, uphill all the way, without a toilet break, whilst towing 6+ tons of animal which would be happier out on a hack - only to do the return journey (still uphill) a day later.

John Robson Silver badge

Re: From what I can recall ....

As I said, you're clearly obsessed with the fossil fuel shills.

John Robson Silver badge

Re: From what I can recall ....

So your arguement is that the second hand market for EVs isn't as mature as the second hand market for ICE vehicles?

AT shows a handful of EVs at or around 3k, these are typically ~10 years old, with 40-70k on the clock (i.e. relatively young and low milage)

Putting in "newer than 2011" and "under 60k miles" so that we're comparing the same segment of ICE vehicles to EVs - the prices are ~2k, which is slightly less, but only by ~150 gallons of petrol (substantially less than the typical motorist uses in a year).

Now that's not quite fair, since the EV driver will need to charge - but that's typically ~10% of the cost of fuel... so the first year of fuel savings already make up the difference in purchase cost. (Yes, I know vimes boots apply here)

I looked at my milage for 2023, and calculated based on my previous ICE vehicle's stats what I'd have spent on fuel - the number was more than my entire (four person) household energy usage (that's gas and electricity combined), and that household usage *includes* 99% of my charging.

John Robson Silver badge
Boffin

Re: From what I can recall ....

No - I'm talking about anthropogenic climate change, and the significant effect it will have on the habitability of the planet for Homo Sapiens.

We are more densely packed than ever before, and have started to affect the climate to a very significant degree, such that the changes are fast, really fast.

Whereas you are saying nothing - other than "CO2 isn't poisonous", which isn't actually the problem with climate change - but you hook onto it because it allows you to deny the problems the (human) world is facing, and causing.

When you've caught up with the rest of the world, and left the FF shills behind then you can have a rational discussion... Until then there is literally no point, since you're in pure denial/conspiracy theory mode and I don't have the time for that.

John Robson Silver badge

Re: may be zero carbon

Actually it’s often mentioned - mostly by people who don’t do their research.

The researchers find that the break even point is well under 20k miles….

John Robson Silver badge

Re: From what I can recall ....

Science… I don’t expect you to (try to) understand.

John Robson Silver badge

Re: From what I can recall ....

"* Over here, cable with BS1363 (a.k.a. 13A) plug, limited to about 3kW, and only intended for emergency use."

They tend to be limited to 10A, i.e. 2.4kW, and there is no reason for them to be "emergency use", you just need to know that your wiring is appropriately sized...

That limit is to give some safety factor for household wiring.

Mine has 32A rated cable from the CU to the socket, then 16A rated to the charger. The (decent quality) socket and plug are also quite happy at 10A, no significant heat output - so the only "weak" point is the fuse - which is quite happy doing 10A all day long.

John Robson Silver badge

Re: From what I can recall ....

Ah yes, the "but this mars bar can support one person for an hour, so it must also be able to support 1 million people for a whole year".

Now *that* is hyperbole.

John Robson Silver badge

Re: "Cost and maintenance are also an issue"

"it's only a tiny, tiny part of the problem"

Well then let's not do anything ever, because no one thing is a single solution to all man's ills.

It's not a huge rollout, but it's a small piece of a larger puzzle.

I assert that you're overstating the scale of the issue:

RAC data suggests just 30% of households don't have capacity for off road parking - and national statistics show that 20% of households don't have access to a car/van.

I would suggest that there is probably some correlation between houses without access to parking and those without a vehicle. It won't be independent, it also won't be an absolute correlation - If it was independent then we'd be down to 24% of households, and my gut suggests that we're more likely looking at 20%.

Of those we then have to eliminate those who have off road spaces where they consistently park elsewhere - whilst they're at work for instance (workplace, station, nearby car park).

Car parks at places which are regularly visited for 4+ hours should have a decent number of low power (7kW or even 3kW) AC EV chargers - we're only having to cover ~20% of households here, so it's not even like every spot in the car park needs a dedicated charger - spreading them out helps in fact, since you're less likely to be ICED.

That leaves a relatively small number of people who don't have regular access to fixed charging, though again, a decent spread of maybe 11kW, or even 22kW capable AC (though few cars will take 22kW AC) at places like supermarkets or other "frequently visited for more than thirty minutes" destinations - and they will also be covered.

And then you need the 50+kW (with 150+ being much nicer, and 350kW being almost overpowered) chargers on (or near) the trunk roads to support long journeys.

Musk claims that venting liquid oxygen caused Starship explosion

John Robson Silver badge

Re: Hyperbole

"IMHO, he is not much more than a modern day snake oil salesman (much like his idol, Trump). Promises the earth and delivers little and very late. Where's that Roadster 2 Elon?"

Basically kick started the EV industry, has revolutionised space access...

The boring company hasn't worked out, and twitter was always going to carry on being a dumpster fire of offense.

Paypal didn't do badly either.

The two things he's done that he actually has an ulterior motive for (making us interplanetary and decarbonising transport) have actually been pretty successful. His time estimates are always optimistic - partly because if you don't at least aim for a tight deadline you'll just miss the later one instead.

John Robson Silver badge

And what good would the methane do without the O2.

Yes, we consider Methane to be the Fuel, and the LOx to be the Oxidiser... but they are both equally important parts of the propellant.

John Robson Silver badge

Re: Its a Test

Probably... and this is speculation... because it gave them additional margins to deal with potential issues earlier in the flight.

John Robson Silver badge

Re: Its a Test

"The better question is why they didn’t just load a mass dummy instead"

Possibly to give themselves better performance margins throughout the early parts of the flight; the extra propellant would have be used if they had had a number of engine failures.

But you don't want an untested vehicle in space with substantial propellant load, so you dump it.

They don't dump it to reduce acceleration (it has the opposite effect), and they have pretty deep throttling on those raptors - just dump some O2, then some CH4 (rather than have an extra, accidental, rocket engine).

Unfortunately the dumped oxidiser did some oxidation... and it oxidised something important.

John Robson Silver badge

Re: Enough with the Elon Musk Snark

No - that was the fondag, and the reinforced foundations - almost no build up at all (because of the wetlands)

They reckoned it would survive one launch, but the ground underneath didn't take the load... which meant that the concrete cracked and at that point it was always going to fail hard.

The "rock tornado" dug a serious crater as a result, but since Elon has described the SH as "the worlds most powerful plasma cutter" that's probably not a huge surprise (once the concrete has failed).

They've since installed a number of deep piles, supporting a stronger platform, with a fairly hefy bit of steel "pancake" on top of that.

And that looks like it survived just fine.

Your pacemaker should be running open source software

John Robson Silver badge

Re: Hahahahahaha

Those things are not contradictory.

Why would closed source software be safer than open source?

Security by obscurity it not security, it' just obscurity.

Patient access to pull data does not require it to be broadcast to all and sundry - only needs one key to be available (and copied into the device) - the patient will share it with the appropriate clinician. They could even update it if they think it's been leaked.

There could be an unauthenticated "what (basic data) happened in the last two hours" for emergency services as they start to put defib pads in place, but that might not even be needed.

And requiring critical software to have updates when vulnerabilities are found is the minimal effort required.

Eben Upton on Sinclair, Acorn, and the Raspberry Pi

John Robson Silver badge

Re: Backwards

That's why raspbian comes with various things preinstalled...

You have a fairly robust environment, with many things available.

Ideally a netboot enviornment at schools would be good - kids can have an SD card, and the systems can just power on and boot from the network if there isn't an SD card there.

John Robson Silver badge

Re: Backwards

"staying true to the Raspberry Pi legacy"

I rather think that's his to determine.

If I recall correctly the intent was to concentrate on low cost machines for education... the massive take up in industry is great, but is funding that original requirement.

Us hobbyists are another group which is great, but not the original requirement.

America's first private lunar lander suffers 'critical' fuel leak en route to Moon

John Robson Silver badge

Re: Some data is better than nothing

"What mission was that? The F9 mission document doesn't list as much payload as Vulcan just sent as a possibility on the F9 ELV. Peregrine was just one of the payloads on the Vulcan flight."

https://en.wikipedia.org/wiki/Beresheet

Feb 2019, and also failed to land. I don't blame you for forgetting. It was also a shared payload, with an Indonesian satellite and a US military test craft also taking that flight.

Vulcan has ~27 ton to LEO capability.

F9 has ~23t to LEO, or 15t ASDS, 12t RTLS

FH has ~64t to LEO, presumably somewhat less with booster RTLS, and would be less still with core ASDS.

(GTO drops from 27t to 8t for a completely reusable variant)

NASA's Artemis Moon missions take a rain check until 2025 and beyond

John Robson Silver badge

Re: No need to rush

"our hardware is performing according to requirements", but we can't guarantee that it will continue to do, because we don't understand some of the behaviour we're seeing.

His jug of water demonstration was particularly powerful for many.

John Robson Silver badge

Re: They don't have a clue

Yes lots of it was...

The best estimate I've found is ~50%

So if you subtract all of that that from SpaceX (which is a little unfair), then they end up with 30% of the global mass to orbit.

Starlink becomes number 1 with 50%, SpaceX (other) is number 2 with 30%.

It's a little hard to put together the rest, I keep getting quarterly results and lack the time/inclination to sum them all.

But looking at Q3 - CASC lifted 25 tons, SpaceX lifted 381 tons, out of a total of ~450 tons

Even if 225 tons (50%) was starlink, SpaceX (other) still has 150+ tons of commercial lift, substantially more than CASC (and we ought to discount their internal programs as well?)

Q3 might not be representative...

John Robson Silver badge

Re: They don't have a clue

Then spaceX make a loss... that's not NASA's problem.

I don't think reentry is going to be impossible though, it's just the biggest remaining "completely untested" thing.

John Robson Silver badge

Re: You don't have a clue

Not jsut the efficiency - if the thrust increases then they can stretch the stack (which they are already planning to do) and therefore carry both more fuel and more "payload" fuel.

John Robson Silver badge

Re: Deadlines

There are a couple of routes to the moon.

If we assume SpaceX manage to get SS/SH working... and that's not an unreasonable assumption, even if the timescale is still under question, then even without SLS the US could still have lunar capability.

Launch (and refuel) the Lunar Lander SS.

Launch a Dragon, rendezvous and dock with the HLS.

Take both craft to lunar orbit.

Drop the Dragon off (potentially with a little extra cargo, see later) in orbit.

Land, do science, return to the Dragon.

This is where we need a little extra deltaV, probably taking some of the HLS payload capacity for a dragon TEI stage - but the dragon was originally designed for a Lunar return, so kick it back into a return trajectory, leaving HLS in LLO as a potential bonus item for later.

As for a Chinese *woman* being next... I'm not sure they're that fussed about getting that particular first, so it's probably a 50/50 shot (assuming that the US don't get there in a reasonable time frame)

John Robson Silver badge

Re: They don't have a clue

If you look at the graphic at 29:57 in Destin's video it's pretty clear that it's starship launches all the way down.

I'm pretty sure that the only refueling is for the starship lander, which will all be starship tankers.

Orion and SLS are one shot disposable devices.

John Robson Silver badge

Re: They don't have a clue

"It seems that for some, SpaceX can do no wrong..."

They can - as their HR fiascos clearly show.

When it comes to rocket engineering, they do seem to produce results.

Even when they get something wrong ("We think the fondag will survive one launch") they work to repair the damage and improve systems far faster than most people would guess.

Yes, I know they nearly went under with the F1, but the F9 has given them a ridiculous share of the market (80% of mass to orbit in 2023, after ~50% in 2022Q4), and they are applying many of the same lessons to SS/SH.

They really don't look all that far away from orbit... reentry is clearly an unknown at this point, but that's not technically required for Artemis - though they'll clearly be wanting to emulate their F9 success.

Kia crashes CES with modular electric vehicle concept

John Robson Silver badge

Re: Standardized

"It's one of the biggest reasons the larger car makers have been apprehensive about getting in to the electric market - they know it's a huge step towards commodification of their product along the lines of washing machines or microwaves, where most people not only won't care about the difference between one brand and another but won't even know that there might be a difference."

I'd argue that the number of people who buy a car based on the engine is pretty small.

The cabin is far more of an important differentiator than the engine for most customers, with the assistance technologies being another useful value add.

What standardisation of voltages and connectors (which has already happened) does is allow for charging infrastructure to be (approximately) universal...

You could try to standardise a "user replaceable" battery component, but charging speeds are already sufficient that it's not all that interesting for the vast majority of use cases any more - some of the micro EVs on the continent are using this kind of "wheel half your battery into your flat in the form of a wheeled suitcase" charging mechanism, and to be honest that looks great, but until it's more common the concept of standardising is somewhat further in the future than now.

This is the concept of havig a "skateboard" with a cab, and a replaceable "back half"... like vans do now, only with the ability to switch them out during the lifetime of the vehicle.

Which is fine, need a pickup this week - go and hire one from your dealer, they can store your default shell whilst you haul stuff to the tip. Need something else next week, get that...

John Robson Silver badge

Re: Standardized

"If someone would come up with an open-source standard"

Then we'd have three more standards than we already do...

https://m.xkcd.com/927/