* Posts by Brangdon

419 posts • joined 15 Sep 2008


China's really cotton'd on to this whole Moon exploration thing: First seed sprouts in lunar lander biosphere


Re: I would like to see the aims of the experiment.

I mostly agree. A crucial area is how development in lunar gravity compares with development in Earth's gravity and micro-gravity. I'd expect it to be much closer to the former than the later. There are a lot of things that go wrong for humans in microgravity and I hope they don't also go wrong in 1/6th g. I don't know if this experiment can shed much light on this.

Spektr-R goes quiet, Dragon splashes down and SpaceX lays off


Re: Stainless Steel?

Apparently carbon fibre is stronger at room temperature, but steel is stronger at cryogenic temperatures and a lot stronger at high temperature, so steal wins overall for this application. It is a very specific type of steel - apparently SpaceX have their own foundry now, and developed a new alloy for the engines.

The steel is a good conductor, so they'll be able to use active cooling instead of a heat shield, which saves some weight overall and is also better for reuse.

It's the weekend. We're out of puns for now. Just have a gander at China's Moon lander and robo-sidekick snaps, videos


Re: due to the energetics on the one hand

Fuel is cheap. Space has been expensive mainly due to rockets only getting used once. That era is ending. Then it comes down to ambition. SpaceX have a detailed plan to land 100 tonnes safely on Mars at reasonable cost. Transit times are under 4 months so the radiation risk is tolerable.

Chinese rover pootles about... on the far side of the friggin' MOON


We do build a lot of satellites, and there are moves to launch them ourselves, eg from a site in a desolate part of Scotland.


SpaceX's Crew Dragon shows up at pad 39A, nearly 8 years after the last Shuttle left


Re: Naming conventions

SpaceX aren't much better. They've renamed the BFR to Starship, even though it won't be flying to any stars.

It's a brand name thing. Their satellite internet will be called Starlink. The Falcon Heavy Tesla pilot was called Starman.

It's 2019, the year Blade Runner takes place: I can has flying cars?


Re: the over crowded and polluted cities

Bladerunner doesn't have over-crowded cities. They are mostly empty, because the general populace have migrated to the colonies. That's why that toymaker has an entire building to himself.

A few reasons why cops haven't immediately shot down London Gatwick airport drone menace


It's not been up continuously for that long. It appears, hangs around until someone notices it and the airport closes, then it goes away. When the airport reopens, it comes back. It can be recharged in between times.

Virgin Galactic test flight reaches space for the first time, lugging NASA cargo in place of tourists


Re: reliability ?

They'll never get reliability so long as they use human pilots. Both their main rivals, SpaceX and Blue Origin, understand this and use automated flight. Virgin Galactic have already killed people from this mistake.

Ecuador says 'yes' to Assange 'freedom' deal, but Julian says 'nyet'



My guess is that he's waiting to see how Brexit plays out. A hard Brexit will mean the end of European Arrest Warrants as far as the UK is concerned. If that happens, he can leave the embassy. He'll be arrested for bail-jumping and probably serve a few days in jail, then be let free. He won't have to face the rape charges. Where-as if the UK is still part of the EU when he leaves, then during his stay in jail the warrant will be revived and he'll be off to Sweden.

Since Brexit day is only a few months away, it makes sense to wait. If Brexit is cancelled, he'll have to think again. If May's deal goes through, I've not idea what the implications are, but I suspect he's still stuffed.

In Space, Still: 20 years since Russia hurled first bit of floating astronaut hostel into orbit


Re: last remains of know-how to send a human in space will have been lost

I take it you are not following NASA's plan to launch humans into space next year? Or SpaceX plan to put humans on Mars within 10 years?

ISS is ancient and falling apart. I'm all in favour of scrapping it and replacing it with something newer and in a more convenient orbit. By which I don't mean Lunar orbit like the Lunar Orbital Platform-Gateway, but LEO. And cancel SLS and use the money to buy launches off SpaceX.

Americans' broadband access is so screwed up that the answer may lie in tiny space satellites


Re: nasty latency

SpaceX are claiming a latency of 25ms. That's not too nasty.

Should a robo-car run over a kid or a grandad? Healthy or ill person? Let's get millions of folks to decide for AI...


Re: Either your brain massively overclocks in an emergency...

> Either your brain massively overclocks in an emergency, to get more done in a short time, or something weird happens to your perception of time.

From your own account, the amount of time it took you to recognise the sign suggests the second one. If your brain was faster, you'd have recognised it sooner. In fact, your brain's emergency mode did not lead to you reacting quicker. As others have said, you just remembered more detail afterwards.

Science: Broke brats glued to the web while silk-stocking scions have better things to do


Re: !My Generation

Good post. I'd add that the "rallying around" has now largely been diverted to social media, posting likes on Facebook or Twitter etc, rather than activity in the real world. As such it can be overlooked by people who scorn social media.

Whether all those likes are an effective measure for actual change is another matter. Sometimes they act as pacifiers without achieving anything. Sometimes they can lead to people organising online for events in the real world. And whether the old-fashioned protest marches achieved anything is debatable too.

'Incommunicado' Assange anoints new WikiLeaks editor in chief


passed the statute of limitations' deadline

"Those charges have since passed the statute of limitations' deadline in Sweden and are no longer being pursued"

The most serious accusation, of rape, hasn't passed the statute of limitations and is still outstanding. It isn't being actively pursued because the Swedes felt it was impossible to make progress while he was in the embassy, but if that situation changes it can be revived (and probably will be).

2-bit punks' weak 40-bit crypto didn't help Tesla keyless fobs one bit


Re: Pektron

40-bit cryptography was also the standard for PDFs. I think it dates back to when anything stronger was banned for export as a munition by the US government. That was ages ago - PDF is long updated - but it's where it probably comes from.

Bug bounty alert: Musk lets pro hackers torpedo Tesla firmware risk free


Re: Another lawsuit filed against Tesla for autopilot crash

Speeding up is expected behaviour if the car in front changes lanes to reveal open highways. The cruise control had been slowed down by the car in front, and when that car is gone it will accelerate to its set speed.

Sometimes that behaviour interacts with a heuristic about ignoring stationary obstacles. Apparently when the car is moving fast, a lot of cruise control algorithms assume anything stationary is probably clutter, because if it was an obstacle it wouldn't be on the highway.

Space station springs a leak while astronauts are asleep (but don't panic)


It was a drill hole. It was probably made on land by mistake and then covered up.

'Surprise!' West Oz gummint is hopeless at information security


If Jonno's account is re-enabled with his old password, it doesn't much matter how weak it was. Jonno knows it regardless.


Re: Par for the course

Nowadays rotation is considered a bad idea, partly because it is so painful for users. Switching it off probably helped security.

Lo and behold, Earth's special chemical cocktail for life seems to be pretty common


Re: Looking for life around white dwarf stars

I read them as saying that if the building blocks are common around white dwarves, they are probably common around other stars, and it's these other stars that might have life. They are not looking for or predicting life around white dwarves.

Ecuador's Prez talking to UK about Assange's six-year London Embassy stay – reports


Re: definition of "rape" in this case is a broken condom

He's accused of having sex with a woman while she was unconscious, knowing she wouldn't have consented had she been awake. That is rape according to British law. A fact that Assange lovers gloss over.

Fake prudes: Catholic uni AI bot taught to daub bikinis on naked chicks


Re: Can they reverse the process?

Yes, they can. It's mentioned in the article.

‘Elders of the Internet’ apologise for social media, recommend Trump filters to fix it


Re: seven figure settlement

Why on earth would he get a seven figure settlement? He'd have to show damages to that amount, and since no-one believed Musk the damages would be close to zero.

If it came to a lawsuit, then his claim that Musk developed the submarine purely for PR reasons would be more damaging. Many people believe it, partly because he said it while claiming to be an expert on the rescue. (I'm not defending what Musk wrote, because it did cross a line, but the diver was being a dick.)

I see Musk has now apologised. Good.



Trump wants to work with Russia on infosec. Security experts: lol no


Re: Whatever Putin has over Trump must be simple

One thing Trump wants is a Trump Tower in Moscow. He's been trying to get this built for many years. It is why he held Miss Universe in Moscow.

If the pee-tape, or something like it, exists, it's probably something Trump would be happy about because he knows Moscow won't let him build the tower unless they have something on him.

(Even though Trump himself wouldn't build the tower, he'd be paid a lot of money to put his name on it.)

Top banker batters Bitcoin for sucky scalability, security


Re: No.... really??

Some digital currencies have inflation. The real purpose is for the inflation to be at a rate free from interference by humans. The reason being, whoever controls how new money is created has enormous power, and history shows that power corrupts eventually.

Otherwise I agree. Central banks don't want to give up that power. They say they need it. They may be right.

USA! USA! We're No.1! And we want to keep it that way – in spaaaace


Re: Monitor and destroy

Hydrogen is usually avoided for a first stage because it has less thrust than other fuels, and because in engineering terms it is a bastard to work with. And not everyone uses it for their second stage, either. SpaceX, for example, Falcon 9 uses purified kerosene for both stages, and their planned BFR will use methane.



It wasn't a slight against the USA. You're both saying the article was wrong: that sending robots instead of humans won't eliminate mistakes. (And if you send a human you have more chance of fixing a problem on-site.)

Australia wants tech companies to let cops 'n' snoops see messages without backdoors


Re: Benefit of the doubt?

To me it sounded like he was trying to distinguish between a back door in the sense of a weakened crypto algorithm, and key escrow. A weakened algorithm can be broken by anyone with sufficient maths ability and computational power, so is a worse option. Key escrow can only be broken by whoever has the keys. Key escrow can seem like a viable option if you trust the keyholder to keep them safe.

That said, the quote, "There's been ideas around for decades that you should create some kind of key that law enforcement can get access to … that's not what we're proposing" could be a rejection of key escrow. But without details of what he is proposing it's impossible to be sure.

SpaceX to pick up the space pace with yet another Falcon 9 launch


Re: little appetite to bother with recovery

In addition to the GTO thing, SpaceX may figure they can get more value by testing experimental landing profiles than by recovering the booster. The booster can't be reused, is too big for museums to handle, and SpaceX have probably learnt all they can from recovering and inspecting its siblings. If they try a new landing profile, they might learn more about how the booster behaves. The data could be valuable but not valuable enough to be worth risking damage to the drone ship for, so they land it without the drone ship.

I don't know if this is what's happening for this launch, but it's a consideration. It's not just not bothering.

'Autopilot' Tesla crashed into our parked patrol car, say SoCal cops


The data isn't publicly available. We know that Tesla cars as a whole got safer around the time that autopilot was introduced, but it was introduced at about the same time that automated emergency braking was added, and it may be the latter which is wholly responsible for the improvement and not autopilot. That Tesla have the data and don't release it is regarded as suspicious by some people.

Beardy Branson: Wacky hyperloop tube maglev cheaper than railways


Re: Bezos is doing both

Bezos current rocket, New Shepherd, is also sub-orbital hops only. He plans an orbital one called New Glenn, but it is years away from its maiden flight. He's not put any commercial cargo in orbit - at most he's done some brief micro-gravity experiments.

Maybe you have him confused with Musk? SpaceX often sends cargo to LEO, GTO and the ISS. He's not put any humans in space yet, but hopes to by end of year-ish.

First SpaceX Falcon 9 Block 5 rocket lobs comms sat into orbit


BFR to fly next

You are confusing the BFR with the BFS. It's the BFS which Musk hopes will fly next year. The BFS is the second stage, and by "fly" he means make small, sub-orbital test hops. It's not as ambitious as you make it out to be.

He's also talked of making 30-50 block 5 first stages, each capable of 10+ launches. Even if SpaceX manage 50 launches a year, that will still take 10 years to get through. So he's not actually counting on BFR flying that soon.

Mobileye's autonomous cars are heading to California. But they're not going to kill anyone. At least not on purpose


Re: Strawmen

Does the bouncing ball actually change your car's movement? Or does it merely cause you to be more attentive? For me when I see a hazard I may only move my foot over the brake without actually slowing down, while I watch for developments. After the bouncing ball I'd be more ready to stop, and paying more attention to where the ball came from in case a child followed, but I wouldn't actually stop or even necessarily slow down. An autonomous car is presumably always paying attention, always alert, and always ready to stop, so doesn't need to predict as much.

Brit govt told to do its homework ahead of talks over post-Brexit spy laws and data flows


Re: What is impossible?

Leaving the EU is possible. Doing it smoothly in the timeframe available with the resources available isn't. It's a complex task.

So when can you get in the first self-driving car? GM says 2019. Mobileye says 2021. Waymo says 2018 – yes, this year


Re: You won't get into the first...

Don't just the best by the performance of the worst.

NASA boss insists US returning to the Moon after Peanuts to show for past four decades


Re: Moon base Alpha

It's easier to live on Mars for many reason. It has an atmosphere, which reduces radiation and micro-meteors, and helps slow down on arrival (so it costs less delta-v than the Moon), and which is a source of CO2 for making rocket fuel for departure. Its day/night cycle is close to 24 hours rather than 28 days, which is better for plant growth, and means you don't need so many batteries to store solar power, and which reduces the temperature extremes. Mars gravity is closer to Earth's. It has plenty of water readily available (which has yet to be proven on the Moon).

The only advantage of the Moon is that it's closer. Admittedly that's a big advantage. In every other way Mars is better.

Password re-use is dangerous, right? So what about stopping it with password-sharing?


Re: one that's also hard to type

There's your mistake. Choose an easy to type password instead. Make it longer so it's just as secure. You'll find you can type "balloon sausage monty pet dribble elephant noggin pleb" pretty quickly and it has around 100 bits of entropy.

(Or would do if you picked the words at random, rather than just making them up like I just did.)

It's World (Terrible) Password (Advice) Day!


Re: use pronounceable if you want to remember the password; random otherwise

Pronounceable passwords of the CorrectHorseBatteryStable variety have the benefit of being much easier to use if you don't have copy and paste available. Especially if the keyboard you are using makes it hard to access symbols, or even numbers. I can type several correctly-spelt English words quicker than I can type a sequence of random characters, even if the words have a greater total length. I type for a living, and most people type at least quick enough to send text messages.

It's wrong to say these passwords would be undermined if other people don't use symbols. Go read the XKCD again, and pay attention to the numbers. Each word adds 11 bits of entropy. That means it uses a dictionary of 2048 words. You get that much entropy regardless of what other people do, and regardless of whether you include spaces or capitals at word boundaries, and regardless of whether the attacker knows the dictionary. (It surprises me how many people cite the comic without understanding this point.) If you need more than 44 bits, use more words and/or pick them from a larger dictionary.

Which highlights another advantage of using correctly-spelt English words: you can calculate exactly how much entropy you have, and it doesn't depend on security by obscurity. All the schemes based on songs or substitutions or whatever, you really have no idea how secure they actually are. And because you know how much entropy, if you need to add a number or something to satisfy someone else's arbitrary password rules, you can just stick a 1 on the end. You won't make it less secure by doing so.

The main catch is that you need to pick your words from a dictionary with a genuine random method. Don't use the first words you think of, or the name of the first thing you see when you look out of the window, because you don't know how much entropy that gives you. Ideally use diceware or similar.

I've got way too much cash, thinks Jeff Bezos. Hmmm, pay more tax? Pay staff more? Nah, let's just go into space


Re: Space tourism, or improving the lives of billions?

Neither Blue Origin nor SpaceX are about space tourism, so it's a false choice. Bezos wants to see a million people living and working in space. He wants to move industry up there to reduce pollution on Earth. Tourism is just a means to raise funding, and to promote interest in space.

Musk wants to save the human species from extinction, another laudable goal. Along the way he is promoting solar power and electric cars to help clean up the environment. In addition he is trying to bring the internet to third world countries, via LEO satellites. That may not sound as important as proper toilets, but with the internet comes education - you can look up how to build a proper toilet online.

Worried we'll make ourselves extinct? Let’s be scientific about it


Re: Well ...

There is now an evolutionary pressure in favour of remembering to change the batteries in your smoke detector.

The pressure is low, because not many people die in fires, but some do (and sometimes their children die too), and so the selection bias exists. Human evolution may have slowed, but it hasn't stopped.

(If you are reading this, take it as a reminder to check your own batteries. When did you last do it?)

Virgin spaceplane makes maiden rocket-powered flight


The number of people who can afford a longish trip in space will increase enormously when SpaceX BFR gets going. They'll have orbital trips of a few hours, and circumlunar trips of a week or two. This is quite likely to happen in the next 10 years, or 15 at the outside. If you can afford Virgin, you probably should hold on to your money for a few more years and then get a much better and/or cheaper experience.


Re: the principle of an air-launched second stage is one worth pursuing

I'm not convinced. It adds a lot of complexity for not a lot of gain. The height and delta-v gains are trivial. The main benefits are avoiding most of the atmosphere, being able to use a nozzle tuned for near-vacuum, and some flexibility over where you launch from. It just doesn't seem worth the effort and complexity of adding a whole other aircraft.


Re: most likely to allow me to get 'above' the atmosphere and back alive

I'd trust Blue Origin's New Shepard over this.

Uber self-driving car death riddle: Was LIDAR blind spot to blame?


Re: with no light

There was plenty of light. Uber's released footage made it look dark, but other night time videos of the same road show it was well lit, and Uber's own headlights would have illuminated more than the released footage showed.

Fatal driverless crash: Radar-maker says Uber disabled safety systems


Re: We must ban all self-driving cars on public streets now

Not all self-driving cars. Just the Uber ones. The Waymo ones are several years ahead of the Uber ones, have done many more miles, and haven't killed anyone yet. It'd be wrong to punish Waymo for Uber's mistakes.

Internet Society: Cryptocurrency probably not an identity system


Re: hmm

Bitcoin doesn't have any particular infrastructure to support this. Another blockchain such as the Ardor platform would be much more suitable. That has persistent accounts rather than ephemeral addresses, and you can tag accounts with certificates eg to show they have been validated to some level.

You must be yolking: English pub to launch eggstravagent Yorkshire pudding


Chocolate scotch eggs

I only discovered chocolate scotch eggs were a thing when my local tea shop started advertising them.

Bitcoin's blockchain: Potentially a hazardous waste dump of child abuse, malware, etc


Re: Does every , um , wallet have a complete copy ,

Full nodes need to have a complete copy. There are light wallets that don't, which work by talking to a remote full node.

Bitcoin includes a scripting language. By using a scripts to decide whether a payment is authorised it gains a great deal of flexibility, to support things like multi signature accounts, time-locked accounts etc. The scripting language can include arbitrary data because nobody bother to make the effort to exclude it. Even if they had, you can encode information into the amounts being transacted.

Uber breaks self-driving car record: First robo-ride to kill a pedestrian


Re: Could we at least give her the dignity of a name?

Early reports suppressed her name because her next of kin had not yet been informed. This is so people don't find out about the death of loved ones from a news report. They get told by a human in a more sympathetic way. Maybe it took longer to identify her next of kin because she was homeless.

Kepler krunch koming: Super space 'scope's fuel tank almost empty


Re: Next time, include a refueling port.

It's usually better to launch a new satellite than refuel an old one. Refueling is quite hard. If you need a human to do it, well, Falcon Heavy is not man-rated and never will be, and BFS will need to be refueled itself before it can reach such a high orbit. If you want to do it without humans, then you need automated docking and other infrastructure that wasn't/isn't available and which adds weight and cost.

By the time they need refueling, the satellites are so old that you'd rather replace them with newer technology anyway.


Biting the hand that feeds IT © 1998–2019