* Posts by MachDiamond

8717 publicly visible posts • joined 10 Aug 2012

Fat EVs may cause 'more death on our roads' – watchdog

MachDiamond Silver badge

Re: Temporary Problem

"If EV technology had advanced as much as ICE over the past 130 years, then your battery would be the size of your fist, you would just swap it at the forecourt and would last 1000 miles."

If that happened, I'd go live in the woods away from those cars. The latent energy in petrol isn't ready for release until it's combined with oxygen so a tank full of fuel can be considered 'safe' for a certain value of safe. A battery the size of your fist would embody all of the energy to move a passenger vehicle 1,000 miles and not need to be combined with anything before releasing all of that stored potential all at once. Boom. I'm not going to do the math, but I expect that the battery would be more powerful than an equivalent volume of plastic explosive.

MachDiamond Silver badge

Re: Temporary Problem

"Solid state batteries expected within a few years should reduce battery size and weight by 30 to 50%,"

Please provide a video of you holding your breath until then and a comprehensive white paper on what exactly defines a "solid state" battery.

MachDiamond Silver badge

Re: Old people want "safe" cars

"This might be something to consider as states lose petrol tax revenues with increased electric vehicle use,"

In the US, some states have already added an EV fee on the registration. It's actually more money than you pay in petrol taxes even in California vs. an economy car like a Toyota Camry or Honda Civic. One would have to drive way past the national average before paying the same in petrol taxes.

MachDiamond Silver badge

Re: Old people want "safe" cars

"Older people want heavier and heavier cars for their perceived protection in crashes."

In the US you can look up the figures and the bigger heavier cars fare much worse contrary to 'common' wisdom. Not only do they not protect their driver/passengers, they tend to injure and kill the people in the other car in car vs. car accidents. The land yachts tend to have a squishy suspension and are really fabulous for long road trips so you don't have to wear a kidney belt like you might in something 'sporty'. My old Buick (RIP) was super comfy to drive long distances.

MachDiamond Silver badge

Re: This is an "Applies to USA only" article

"f you can get insurance, you can put it on the road."

That's provided that the vehicle started life as something built by a recognized manufacturer and hasn't been heavily modified. If you brew your own, you have to get it certified as road worthy and show it complies with size and safety requirements. You could start with a Ford and give it a taste of the cutting torch, welder and toss in an engine control mod chip and get away with it. That can end if you get caught and the police officer takes issue with those changes for not meeting minimum standards.

MachDiamond Silver badge

Re: This is an "Applies to USA only" article

"US: Parents, including learning their mistakes."

Not entirely. I had driver's training in school from a "professional instructor", but got much better tuition from my parents. We'd go to a lonely section of a parking lot and practice parallel parking, reversing, etc. On the road I was shown how it's not safe to turn the wheels for a turn across traffic at an intersection so if hit from behind I wouldn't be pushed head first into oncoming traffic. The 'professional' never mentioned that. Many more lessons were based on where we lived and the sorts of conditions we had rather than just getting lessons by somebody following an approved curriculum.

MachDiamond Silver badge

Re: American cars are too heavy - solution blame electric cars

"The average car is much longer and wider than 20 years ago."

In the US, the width of a car has a maximum. The length is regulated too, but a passenger car as long as an articulated lorry would only be needed with somebody looking to father more children than Elon Musk.

Chinese company claims it's built batteries so dense they can power electric airplanes

MachDiamond Silver badge

Re: Battery materials???

"but no one can deny that the EROI (energy return on investment) in oil will continue to decline. "

It depends on the oil. Light/Sweet has the best eROI and the tar sands in Canada are some of the worst. In a way you are correct in that when L/S crude is found, they pump the heck out of that reservoir until it's dry while not putting in as much recovery effort in wells that produce Heavy/Sour where it takes a lot of refining to shorten the Hydro-Carbon chains and remove the contaminants.

MachDiamond Silver badge

Re: Denial is not a great way to keep up

With the claim also backed up by promising production this year, I'm more inclined to believe than I would if there was just a claim they've done it in the lab and more work is needed. This is bad news for Tesla and their projects to bring battery production fully in-house. Other auto makers that aren't tied to long term contracts or gobs of capital equipment for making cells will have the ability to adopt these new cells as soon as there is volume production. Tesla can do the same, but it means trashing what they've already done towards making their own.

MachDiamond Silver badge

Electric power aircraft are far off in the distance. If cars, trucks and trains were electrified first, the fuel aircraft are burning is less of an issue. A 500Wh/kg rechargeable battery in a car would mean the same range with much lower weight leading to better efficiency. The same for HGV's and it would start to be very viable to add battery tender cars to trains (trams, trollies, etc) to make it easy to bridge gaps where overhead lines aren't feasible like in low tunnels and complex stations.

As an aside, a company is proposing to add a train service in California between Los Angeles and San Francisco (likely Emeryville east of SF) using the coastal tracks Amtrak uses for the once a day Coast Starlight train (16 hour schedule). The new service would be a sleeper service that departs LA at 10pm to arrive in SF at 8:30am so it would be going around 50mph. I didn't see mention of the schedule for service going the other way. It would be nice to see that route be electrified and used more often so the cost can be amortized. I've been banging on about more overnight trains in the US for ages now. Rather than battle lines and indignities at airports, it would be good to travel while asleep (I sleep well on trains). It takes longer than booking one of the 50+ flights there are between the cities daily, but flying is one hour in the air and 4-5 of everything else that isn't putting miles towards the destination. The distance is likely about the minimum viable distance for electric airplanes since people often find it easier to drive between point closer to save time. This means that even a 'slow' train service can be a better alternative to electric planes given the right set of assumptions.

MachDiamond Silver badge

"I suppose I would expect to see batteries in airlines as modular things that get swapped between each flight (no down time for charging)."

Very doubtful that would be allowed. The process required on aircraft for work being done on that scale isn't something that done in a hurry by PFY ramp staff. Varying a fuel load can be done as it's a liquid and still going into tanks with a well characterized weight characteristic. It would be tricky to vary the number of battery modules and there would also be the problem of depleting modules in one location and accumulating a bunch of them some place else. The same sort of problem shown with the same sort of thing being done with passenger cars.

MachDiamond Silver badge

Re: Presume you're referring to 911

"Much of the fires in the buildings were paper and other combustibles in the buildings, with possibly some of the aluminium from the fabric of the aircraft contributing to the fire"

All of that along with a nice air flow by the building sticking up so high. A hybrid rocket engine is a lump of plastic or rubber with NoX as the oxidizer. Just consider how much plastic there is in an average office. Douse an office with kerosene and spark it off with a fan blowing and not much will be left.

MachDiamond Silver badge

Re: Battery materials???

"Sure, but not many people can afford an engine that costs 8 figures to buy, a 30-person team to maintain and lasts less than 5,000 km!!!!"

I've never noticed all of the emission gubbins being put on an F1 engine either. VW had to fiddle settings so their TDI engines would pass US testing yet still get 50+mpg. I recall that causing some issues for the company.

MachDiamond Silver badge

Re: Battery materials???

"For comparison, the petrol energy density of around 12,000 Wh/kg is what's stored in the fuel, but the best car engines are maybe 35%-40% efficient "

The source of the petrol has to be considered as well. It doesn't come out of the ground ready to stack in a car's fuel tank. It takes a load of electricity to refine the crude oil into petrol and then get it to a station where a bit more electricity is added to take it from the storage tanks to the car. None of that energy gets embodied in the fuel so it's not there to be extracted.

MachDiamond Silver badge

Re: Pling!

"I also hope they don't burst into flames as easily, or burn as hot for as many hours unextinguishable without complete immersion in swimming pools.

Number of charge cycles, safety and cost to manufacture are all going to need to be in-line for the cells to be viable.

SpaceX's second attempt at orbital Starship launch ends in fireball

MachDiamond Silver badge

Re: Today's SpaceX Success

"Saturn 5 was built on earlier NASA programs which had PLENTY of failures."

Most of that was from a 'bottom up' approach. That's where you build a small part, test it, make improvements and then combine subsystems in to bigger assemblies and test those. It saves a bunch of money and sometimes if you catch a flaw early, you don't have to redo everything that suddenly has to be modified to fit with the updated component. For a big bit of engineering, this is a good way to go. In a 'top down' approach, you design/build the whole thing and then pull the big red lever and see what happens.

Virgin Galactic has the Top Down problem. They assumed that the hybrid rocket motor could be easily scaled up from the one used in Space Ship One. The problem is that rubber fuel grain burns very unevenly half way through its use to the point where it's a health issue for the passengers and hard on the airframe. It pulses like mad. A Nylon fuel grain works much better although they needed to use Helium in addition to Nox to regulate the burn and that added a bunch of plumbing and took away some paying seats to accommodate. They are still trying to preserve the airframe as built by fiddling with the rocket motor to force it to work for their needs. IMO coming from a background in engineering and aerospace, they should have spent the time to get the rocket motor all sorted before finalizing and building the airframe. That way they would have been able to build the airframe around the power plant and gone from there. They can't take out those seats now for the Nylon motor as the flights would lose money even at a price of US$400,000 a go. They also have tickets pending they sold early on at $250k each.

MachDiamond Silver badge

Re: Today's SpaceX Success

"Sadly in the early 1970s the company did not have a high-speed camera which might have showed which part failed first leading to a cascade of failures."

High speed and thermal imaging cameras are two of the most awesome tools. I wish I had a thermal camera way back when I was working on audio gear. It would have saved so much time and so many blisters on my fingers to see a component was getting far too hot.

MachDiamond Silver badge

Re: Starship hasn't had the most successful history?

Update, they destroyed the launch pad. https://www.youtube.com/watch?v=UdxhN9wV4jM

MachDiamond Silver badge

Re: orbital velocity

"Somehow the numbers don't add up"

A whole bunch of engines were lost. 6 failed rather quickly and more as it continued.

It's really bad when you factor in there was no payload. The Starship was empty and not loaded with the rated 100 tons. Nor were there any internals to secure a payload, nor a mechanism to open and close the pod bay doors.

MachDiamond Silver badge

"what strikes me is the 'long and thin' configuration."

Balance a long thin thing on the end of your finger and move to keep it upright. Now try to do the same thing with something short and fat with the same mass and volume. The long skinny thing will take less to keep balanced and the short fat one will hit an unrecoverable point much more quickly.

MachDiamond Silver badge

Re: All hail the successful test!

"[Will I get my blue badge for free?]"

I read a story today where a fan club for a footballer has a blue check while said footballer doesn't.

MachDiamond Silver badge

"The debris field from the pad (crater McCrater face) alone is quite spectacular, "

When they were doing the cold flow test and got a big bang that damaged the launch stand, I was surprised at all of the junk sitting around. I don't understand why it wasn't moved or driven off to be out of the way. Video is one of the best tools so to have such a big dust cloud obscuring the rocket at lift off isn't a good thing. Real launch facilities use flame trenches to guide the plume in a know direction and away from the immediate area where all of the fuel and oxidizer tanks are located.

MachDiamond Silver badge

Re: Many things

"> Raptors are tested individually

oops"

Well, they are tested individually to qualify them after being built. Plenty still go boom so there's much more work to be done.

Some years ago I got to tour the Air Force Research Lab's Rocket Ridge at Edwards AFB and stood on the test platform where pairs of F1 engines were tested to see how they interacted. Amazing site that's not open to the public for tours. We had a liaison from NASA arrange it for us when I was working in aerospace on rockets. We couldn't bring cameras or even phones with us and the base photographer never delivered on the portrait he took of our group all standing on a F1 test stand.

MachDiamond Silver badge

Re: Many things

"A more interesting test would be to light the SRBs (14.6MN each) with some hold down clamps and see if anything survives."

Do you mean on the launch pad? They do test those SRB's at a site in Utah. Pretty spectacular.

MachDiamond Silver badge

Re: bad, very bad

" it looked like a cobled together Estes"

I have boxes full of them and they are still sold. I like my high power rockets, but I don't like the sometimes very long walk to retrieve them.

MachDiamond Silver badge

Re: Today's SpaceX Success

"How much money was spent before the first Saturn V flew and how much money was spent before Starship flew."

Early on NASA was doing huge amounts of basic research into rockets. You can look up the loads of information they have on just about every combination of fuel and oxidizer with data and discussion on the pros and cons of each combination. There was also lots of research into metal and alloys. Chemical compatibility. Metal coatings. Wire insulation, etc, ad nausem. It would take a years long effort to comb through all of the accounting to separate what the Saturn 5 cost devoid of that R&D. I don't even know if it's possible since a bunch of that paper work, and it was paper, has been fed into the shredders.

MachDiamond Silver badge

Re: Complexity ≠ Reliability

"Falcon Heavy engines aren't buried in a mass of flame"

The Falcon 9 rockets use the Merlin engine and Starship uses the Raptor. The Merlins have a lot more development and refinement compared to the Raptor and the Raptors are being asked to produce even more thrust than anything in their size category has done before.

A better test program might have been to use the Falcon rocket bodies with 3-4 Raptor engines to get them sorted before committing to trying to make them go 33 at a time on Super Heavy plus the 6 on Starship. Maybe they could have developed a Falcon variant with 4-5 Raptors that could boost heavier payloads or get top speeds good enough to fling satellites to Jupiter/Saturn/Venus on more of a direct path. On top of spending hundreds of millions to get Starship to operations status, there isn't a market for shifting 100t to LEO and only Starlink seems to need the volume to be able to launch loads of the v2 satellites. If it was just mass, the F9H would be used since it doesn't fly very often.

MachDiamond Silver badge

Re: Starship hasn't had the most successful history?

"look at Astra, Firefly, and Relativity"

I know Tim Ellis at Relativity. His goal is a nearly 100% 3D printed rocket so they are really pushing the envelope. Firefly's failure on their first go was a bit of a problem, but they didn't go into the launch stating chances were good that it would fail. They wanted to get a good launch and only have refinements to make. I doubt that Vandenberg SFB would allow them to make the attempt if their leadership was just shrugging their shoulders and saying "maybe it will work, maybe not. Let's push the big red button and see.".

MachDiamond Silver badge

Re: Wrong

"The 9 Starship tests all launched successfully,"

If the goal is a reusable system, that landing part is really critical. An airplane that can't land is coffin. A car that goes 0-100 in a couple of seconds is worthless and dangerous if the brakes are faulty.

MachDiamond Silver badge

Re: Starship hasn't had the most successful history?

"Oh rly? What, oh great and knowledgeable one, should it have achieved? Do you, perchance, have the test specs?"

The minimum test goals were 1)lift off, 2) don't destroy the launch platform and 3) stage separation. That's what was published and discussed by SpaceX talking heads prior to launch. Elon just happens to be really big on changing anything to be able to declare a success.

MachDiamond Silver badge

Re: Starship hasn't had the most successful history?

"Really?? I look forward to seeing your entry into the orbital rocket business. Clearly you are all knowing."

I've been out of the company for some time, but one of the landers I worked on is still a goer with over 270 take offs and landings and no crashes.

Yep, been there, collected a prize from NASA. Got a tub full of shirts.

MachDiamond Silver badge

Re: bad, very bad

"so once X is low enough that there should be sufficient good engines to lift the craft then you can start full assembly testing."

As stated by SpaceX the number of of failed engines they can sustain and still complete a mission is 2.

MachDiamond Silver badge

Re: Today's SpaceX Success

"The Saturn engineers were surely no smarter than SpaceX's, so what is the reason for the difference in results?"

Many of SpaceX's senior engineers have come from careers at NASA and NASA's contractors. NASA doesn't build the rockets themselves.

MachDiamond Silver badge

Re: Starship hasn't had the most successful history?

"SN15 was the first Starship to successfully land again, after a flight to about 10km altitude. "

SN15 was an empty hull test article. It didn't have any useful bits fitted inside to hold cargo or passengers or an ability to return from orbit. It also hasn't been flown again. Hmmmm, I wonder why they didn't do that. One flight could be a fluke, but two on the same 'reusable' hull would be something.

MachDiamond Silver badge

Re: Starship hasn't had the most successful history?

"Musk encourages test to failure."

That was not "Test to failure". You'd get that by pushing a design to exceed its design limits. This completely failed to do the minimum it should have. Just lifting off is simple and no test.

MachDiamond Silver badge

bad, very bad

There were a lot of those Raptor engines going off-line. Right off the bat 6 died (they said 5, but it was obvious to see it was 6) and more kept popping without any update to the count. Notice all that green mist? That's Copper used in the nozzles being burned through. Notice lots of bright bursts and flames shooting off to the side? More problems, not gimbaling for course correction.

The Raptor engines have been a big issue. People near the test site in McGregor have been posting videos of engine testing failures left, right and center. They don't have them sorted yet so this launch attempt was destined to fail. And, fail it did. One of the three main criteria on the test card was stage separation. They didn't get to that point and let the rocket continue for a long time after it was clearly in trouble before detonating the range safety explosives. I expect there will be words about that unless it needed to be left for the rocket to be well clear of anybody or any built thing below.

I've been playing with hobby rockets for decades and spent some years working at a rocket company developing reusable landers. I could tell from watching the plume that they had fatal issues beginning shortly after lift off. Perhaps even immediately after engine light, but I haven't see any good views of that. The company I was with always went to the test site with a belief that we'd get a good run. It didn't always happen, but we'd never go out expecting that there was a strong possibility of a catastrophic failure. Trying to analyze a bin full of bits is much harder than making sure the design was viable in the first place.

MachDiamond Silver badge

Re: Thunderbirds are Go!

"Sure, if your cock is 1cm in diameter and 13cm long, in which case you have a very weird cock."

I had a female astronomer friend once tell me it's the width, not the length. I 'think' she was talking about telescopes, but she was married so I at least pretended that was it.

MachDiamond Silver badge

Re: Why did it take three loops to find the launch abort button?

"It seems like as soon as the initial "flip" didn't result in a successful separation they would have popped it for safety reasons"

I watched some video from inside the separation line with a another view of a telephoto image. As soon as the rocket veered, I could see daylight coming through and that meant there was no way it was going to separate cleanly. That assembly isn't designed for being torqued sideways. I have to give the credit for making it strong enough to stay together through that.

MachDiamond Silver badge

Re: Complexity ≠ Reliability

"The Russians tried building a rocket (N1) with a large number of engines and they ran headlong into the problems caused by the complex plumbing."

The USSR tried hard to build a very large engine like the NASA F1 but couldn't get them to work. The tooling and machines needed to make them were also very custom so they decided to make engines much smaller to utilize more common machine tools and give them some redundancy should an engine or two fail. It looks like they went too far in that smaller/more direction and it bite them in the backside.

MachDiamond Silver badge

Re: Wrong

"As far as I can remember, SpaceX has only lost two flights (and those were in the early days)"

They've lost a bunch more than that. The upper stage of Starship crashed and exploded all but once as they tried to launch it.

MachDiamond Silver badge

Re: Starship hasn't had the most successful history?

"AFAIK no.1 success criteria for the flight was not to trash the launchpad, then lift-off, both of which they seem to have achieved"

Stage separation was also a minimum goal for success, but hey, a little revisionist history and viola, Success!

Meta's Zuckerberg paid $27M in 'other' compensation for 2022

MachDiamond Silver badge

Re: Private

"Jets. I still don't know why people use them. They seem to crash more than commercial airlines. At least he could afford 1st class every time, I'm wondering if it would also be cheaper."

They don't crash so much more that the real chance of dying in a crash is that much greater. Even in first class, the accommodation isn't on the same level as flying private. With a smaller private jet, more airports are available so it's easier and faster to get from and to. The TSA isn't tossing the luggage of people on private jets and having a nail file isn't going to lead to being tackled by 'security' with a serious dose of public shaming thrown in. The lounges are often on the opposite side of passenger airports and those lounges are for people that aren't just allowed to have their limo bring them directly to the plane. People that subscribe to a shared service have to go through the FBO's office, but some of those are really nice with catered meals and fresh cookies hot from the oven. They'll even offer private rooms with internet and someplace to catch a nap if the plane isn't there and ready.

First Class on a public airline is much cheaper. Elon flies on the biggest of the Gulfstreams and a cost in the neighborhood of $5,000/hour might even be on the low side all in. It's been some time since I've been told what the going cost is. I know fuel has shot up and many rich execs will insist on two pilots and an attendant.

Wrong time to weaken encryption, UK IT chartered institute tells government

MachDiamond Silver badge

Re: Help! I'm confused.

"Nowadays they probably all just use Signal or WhatsApp, and because those are free to use rather than costing a lot of money"

What if the bad guys use a whole bunch of those free services in rotation so the good guys would have to get all of the comms to follow a message chain? Throw in a couple of jokers such as PGP'd emails and physical postcards to make it even harder. If I send a postcard of the Golden Gate Bridge, Tower of London or any other hugely popular landmark where people are sending those postcards all of the time, it means something. The writing on the card can be anything or might have one word that modifies meaning.

MachDiamond Silver badge

Re: Doh!

"I hope we are missing a subtlety, and some other method of demonstrating a mens rea has actually been used, like, for example, existence of a a viable collection of custom-made parts that can be assembled into a firearm."

The person was making handguns, but the press release from the police emphasized that they had seized gun making equipment making it sound like specialized tools and machines rather than garden variety hobbyist tools. Everything in the photo they included could be purchased online or in a local shop. They even grabbed a case with a set of drill bits and some screw drivers.

MachDiamond Silver badge

"Are you saying you didn't set up a specific email address for that bank? That's email security 101."

And a really good idea to have your own domain so you can add and delete email addresses at will. I have a stack of email addresses. Some are used for specific things and others are throw away accounts that get deleted the moment they start getting spam.

MachDiamond Silver badge

Re: Reading suggestion

"Look for Little_Brother (available for download) by Cory Doctorow"

That's a great story and illustrates how a set of observations can be made to look good or bad for a person depending on how you slant the narrative around those 'facts'.

Chromebook expiration date, repair issues 'bad for people and planet'

MachDiamond Silver badge

"But to make it more fun and challenging all these machines are donations so the whole classroom isn't the same model and they are also different from all the other classrooms"

The classrooms can have the same computers and OS and the donated units can go to students so all of them have a machine at home even if their parents can't afford to buy one. We're talking mainly word processing and the ability to visit web sites and exchange email, not fluid dynamics simulations.

I've never had the same make and model of computer at work that I have at home other than now and that's due to being self-employed. I don't see the problem with being able to work on different computers but I think your concern is more about support which many teachers can't do. I've seen comments that some computer requirements for a class are being manufactured when there isn't a good argument other than "write a syllabus that incorporates computers in the lessons" sort of thing.

Europe wants more cities to use datacenter waste heating. How's that going?

MachDiamond Silver badge

Re: When the Arctic ice cap is sufficiently melted

"I guess you've never been around one when it does its weekly or monthly diesel generator testing? I sure wouldn't want to live in a single family home next door to that."

As opposed to diesel city busses going by several times a day? I'd call generator testing a minor thing. Traffic is a major issue in siting businesses in residential areas and a data center has very little of that other than set up and refits.

MachDiamond Silver badge

"I was given to understand that one reason that many of the reactor fuel rods come from Russia is that they have been turning the soviet unions nuclear weapons into reactor fuel, and recycling from a weapons grade material downwards to a middle grade fuel is much cheaper than making it from scratch, especially if the weapons grade material is essentially "free"."

Russia was also having an issue processing the material themselves so it was backing up. The US buying up that 'packages' to recycle into power plant fuel was a bonus to getting it out of Russia and preventing it from being sold "on the left".

MachDiamond Silver badge

"Lots of 60-90 deg C air is not particularly useful."

If your food processing company needs to generate steam, it would be easier to start with water that is already 80C. There are lots of other processes that can use heat at that temp as is or would benefit from being able to pre-heat using that supply if it will reduce energy costs.