I think part of the problem is that a hobbyist's prototype is also (usually) the final product, and therefore the parts have to be strong and look nice. Often 3D printing -- especially that available the hobbyists -- can't provide sufficient quality. Whereas a manufacturer doesn't mind if their prototype is fragile or a bit rough-around-the-edges, as long as it works well enough to test.
So 3D printing, as it currently stands, has more applications in industry than at home. Hopefully that will change as printers get better and cheaper.
You'd be surprised at how effective seemingly benign things like this are. It sounds akin to a Milwall brick.
You'd be surprised at how effective bare knuckles are. As long as the hijackers have no easy access to the cockpit and are heavily outnumbered by highly motivated people, they stand no chance (this was not the case for the Milwall hooligans). No improvised weapon is powerful enough to overcome the difference in numbers and shift the balance of power. The challenge is going to be ensuring in the long term that ordinary people remain highly motivated to resist aggressors. The TSA's scare tactics come in for a lot of (deserved) criticism, but at least they keep people keyed up.
Yet it can smash a coconut in multiple pieces in one hit according to the article. He did 2 years of research so it would be rather rubbish if he came up with a armory of weapons that fall apart on first use.
Sounds impressive doesn't it. But if you tried you could easily smash a coconut with your bare hands. However it would be very different if the coconut had arms and legs and was defending itself. And if there were a hundred of them, you would soon be overwhelmed.
If your goal is to injure one random person on a plane then nothing and nobody can prevent you. Almost anything will serve as a weapon, and if you are reasonably strong you don't even need a weapon. But that's a preposterous idea, because the remaining passengers will flatten you and you will spend the rest of your life in jail.
If your goal is to take over a plane then a rolled-up magazine laced to a handful of trinkets will not help.
The weapons in the photos look scary, but I bet they'd be really rubbish in real life. For example, the club is made from a rolled up magazine and some Liberty statuettes. It is small, not very heavy, not very sharp, and would probably fall apart if it was used.
Really any of these weapons is insignificant compared to what an fit but unarmed human can do. And that's why aeroplanes are safe these days: any hijacker will have to take on a hundred or more strong and highly motivated passengers.
All this does is ensure that devices will be destined for the landfill that much earlier, but of course that is a "feature".
Well... I guess you choose your DIMMs according to their expected use. JUST LIKE EVERY OTHER COMPONENT IN EVERY DEVICE YOU EVER BUILD!!!
Gaaah!
As for replacing consumable parts - do you replace failed components on motherboards or SSDs? What do you do with a processor that has a single damaged transistor? Some stuff just isn't repairable, but there's a trade off to be made. My phone has a replaceable battery, but the case falls to bits rather easily. Consequently I will probably replace the phone well before the battery wears out. In contrast my Ipod does not have a replaceable battery, but I like it because it is very tiny and very robust.
For circumstances where this new type of memory module could be useful, see the fourth sentence of the summary.
I was under the impression that a control system implies a closed loop or feedback mechanism
Feedback is a great way to stabilise a system, but it is not essential. A stepper motor - even a precise one, like the one in your watch - does not require readback from a position encoder to function. Digital audio amplifiers do not need negative feedback in order to achieve proper linearity, like analogue amplifiers do.
Sometimes it is desirable to do without feedback. The auto-focus mechanism in a professional camera operates without feedback in order to work at the highest possible speed. The lens motor and AF sensor are carefully calibrated so that focus is achieved in a single measurement-movement cycle. This is faster than making multiple measurements, which requires the lens motor to be stopped during each measurement. Feedback is only used to confirm autofocus success, and trigger a second attempt in case of failure.
Sensible merchants would just use divisible-by-5 prices to avoid issues with rounding.
This doesn't always work. A common example where it doesn't work is grocery stores where certain items are sold by weight.
Prices are always rounded, whether it's to the nearest cent or to the nearest five cents. Sometimes you win a tiny bit, and sometimes you lose a tiny bit. On average it makes no difference, so long as the rounding unit is smaller than the cost of the item. And not many places keep items priced below 5c.
This problem is not specific to 3D printers. Just ask Sheffield Forgemasters, who famously made an "oil pipe" for Iraq back in 1990. Oddly, the pipe was enormously strong and specified to very fine tolerances. Turns out it wasn't for oil.
Chernobyl was a horrific design even by the standards of the time. Modern designs are immune to the kinds of accidents which happened at Three Mile Island, Chernobyl, and even Fukushima.
Coal burning also releases more radiation than nuclear power does. If the same safety rules were applied equally to both types of power, nuclear would come out way ahead.
Absolutely. And tinkering pretty much requires a keyboard, so the majority of Android or iOS devices are physically unsuitable for that kind of use. Carry a laptop when you need it and a tablet when you don't. I can see the attraction of a slim, light tablet device when you just need to check emails or buy tickets, and although the prices seem rather high for such simple devices it's obvious that people are happy to pay. But no matter how good these tablets get there will always be tasks which need a better (and bigger) human interface, and that's where PCs are unbeatable.
The ITER project has an overly complex management for purely political reasons, and that causes complexities, delays and increased costs.
Sure, but that's the nature of huge projects. They require huge amounts of money from numerous sources, and each source wants to make damn sure they get something in return for their investment. Could a more efficient management structure be imagined? Maybe. Could it ever actually be implemented? No.
However the managers think everything is fine.
They say everything is fine because if they don't the investors will lose confidence and the project will collapse. The actual lack of fine-ness causes many headaches for the scientists and engineers who have to deal with unrealistic planning, but somehow they usually find a solution. Think of it this way: the managers say what they say because they have more faith in their staff than they do in the politicians funding the project.
If the risk was obvious, I would agree. However I'm not sure that one's vulnerability when cycling is really appreciated - just as people didn't used to feel vulnerable when driving without seatbelts. Even a minor fall onto hard pavement can easily break bones, and if the broken bone happens to be the skull then you can be in real trouble.
A little while ago I took a tumble when a startled animal ran into my bike. I landed on my helmet, which cracked, and was dazed enough to earn a day in hospital. Later, when a road safety group visited my workplace, I got a chance to find out roughly what kind of impact I had taken. They took the remains of my helmet and hit it with a hammer on an undamaged area until it showed damage similar to the original fall. It required quite a serious blow with a heavy hammer. They then delivered a similar blow to a force-measuring stand, which indicated that the force delivered was far more than that needed to break a skull.
In short, even on an empty country lane an unlucky fall can kill you. Until recently I didn't know that, and I suspect lots of other people don't know it either.
The grade of the helium is entirely irrelevant. The helium used to cool superconducting MRI magnets is recycled over and over: it doesn't wear out, and impurities are automatically removed during the liquefaction process. Wasting "old" helium is just as bad as wasting fresh.
Just because you're a "spy" doesn't mean you're not in a group of plane-spotters that plan a trip to Greece. Hell, sounds like a perfect persona to assume to me.
Put yourself in the shoes of the spy. Your choices are
Plan A: be conspicuous. Run a high risk of being stopped, but have a story and hope you can bluff your way out.
Plan B: be discrete. Try to avoid being stopped, although if you are caught you are doomed.
Opting for Plan A means you have to infiltrate a plane-spotting group. Then you have to persuade the group to go to the base you're interested in. When you get there you can only take pictures consistent with being a plane spotter, or your cover story is blown. And when you are stopped (which is certain, because photography is forbidden), you have to hope that none of your friends mention your recent membership of the group, or your curious interest in this particular base. That takes a lot of time and work, the information you can gather is constrained, and the risk is substantial.
Plan B is far easier, doesn't suffer from the limitations of Plan A, and if you do a good job of hiding your camera the risk of being caught is low. And yes, I have read too many spy novels.
This has happened before. A group of British plane spotters were convicted of spying and sentenced to 3 years in jail. It doesn't seem to have occured to the Greek military that real spies will be a little more discrete in their methods.
This is the best answer so far by a mile. The Raspberry Pi has all the hackability of the 8-bit machines we grew up with, but runs a modern operating system with modern programming languages. And of course comes with plenty of games.
In addition to the usual accessories, I'd recommend getting a dedicated screen so that the RPi isn't competing with the telly for attention. Other useful things to have include a case (transparent of course), a powered USB hub (for WiFi and storing data to USB keys) and a spare SD card with the OS installed on it. If he's interested in electronics, look out for the recently released "Gertboard" interface - it's more electrically robust than connecting directly to the RPi. And books. Lots of books, on paper.
would the wright brothers be expected to provide valuable input on the latest stealth bomber?
If they'd been working with aeroplane technology and keeping up with progress for the 109 years since Kitty Hawk then yes, I think they probably would have a few useful ideas.
Slashdot Mirror
I think part of the problem is that a hobbyist's prototype is also (usually) the final product, and therefore the parts have to be strong and look nice. Often 3D printing -- especially that available the hobbyists -- can't provide sufficient quality. Whereas a manufacturer doesn't mind if their prototype is fragile or a bit rough-around-the-edges, as long as it works well enough to test.
So 3D printing, as it currently stands, has more applications in industry than at home. Hopefully that will change as printers get better and cheaper.
You'd be surprised at how effective seemingly benign things like this are. It sounds akin to a Milwall brick.
You'd be surprised at how effective bare knuckles are. As long as the hijackers have no easy access to the cockpit and are heavily outnumbered by highly motivated people, they stand no chance (this was not the case for the Milwall hooligans). No improvised weapon is powerful enough to overcome the difference in numbers and shift the balance of power. The challenge is going to be ensuring in the long term that ordinary people remain highly motivated to resist aggressors. The TSA's scare tactics come in for a lot of (deserved) criticism, but at least they keep people keyed up.
Yet it can smash a coconut in multiple pieces in one hit according to the article. He did 2 years of research so it would be rather rubbish if he came up with a armory of weapons that fall apart on first use.
Sounds impressive doesn't it. But if you tried you could easily smash a coconut with your bare hands. However it would be very different if the coconut had arms and legs and was defending itself. And if there were a hundred of them, you would soon be overwhelmed.
If your goal is to injure one random person on a plane then nothing and nobody can prevent you. Almost anything will serve as a weapon, and if you are reasonably strong you don't even need a weapon. But that's a preposterous idea, because the remaining passengers will flatten you and you will spend the rest of your life in jail.
If your goal is to take over a plane then a rolled-up magazine laced to a handful of trinkets will not help.
The weapons in the photos look scary, but I bet they'd be really rubbish in real life. For example, the club is made from a rolled up magazine and some Liberty statuettes. It is small, not very heavy, not very sharp, and would probably fall apart if it was used.
Really any of these weapons is insignificant compared to what an fit but unarmed human can do. And that's why aeroplanes are safe these days: any hijacker will have to take on a hundred or more strong and highly motivated passengers.
All this does is ensure that devices will be destined for the landfill that much earlier, but of course that is a "feature".
Well ... I guess you choose your DIMMs according to their expected use. JUST LIKE EVERY OTHER COMPONENT IN EVERY DEVICE YOU EVER BUILD!!!
Gaaah!
As for replacing consumable parts - do you replace failed components on motherboards or SSDs? What do you do with a processor that has a single damaged transistor? Some stuff just isn't repairable, but there's a trade off to be made. My phone has a replaceable battery, but the case falls to bits rather easily. Consequently I will probably replace the phone well before the battery wears out. In contrast my Ipod does not have a replaceable battery, but I like it because it is very tiny and very robust.
For circumstances where this new type of memory module could be useful, see the fourth sentence of the summary.
I was under the impression that a control system implies a closed loop or feedback mechanism
Feedback is a great way to stabilise a system, but it is not essential. A stepper motor - even a precise one, like the one in your watch - does not require readback from a position encoder to function. Digital audio amplifiers do not need negative feedback in order to achieve proper linearity, like analogue amplifiers do.
Sometimes it is desirable to do without feedback. The auto-focus mechanism in a professional camera operates without feedback in order to work at the highest possible speed. The lens motor and AF sensor are carefully calibrated so that focus is achieved in a single measurement-movement cycle. This is faster than making multiple measurements, which requires the lens motor to be stopped during each measurement. Feedback is only used to confirm autofocus success, and trigger a second attempt in case of failure.
And they're only planning to make a plan, according to the story title.
Do they have a plan for that?
... fucking ... shit ... fucking ... 'tards ... bollocks ... fucking bollocks ... piss fucking ...
Breathe into the paper bag, sir.
Sensible merchants would just use divisible-by-5 prices to avoid issues with rounding.
This doesn't always work. A common example where it doesn't work is grocery stores where certain items are sold by weight.
Prices are always rounded, whether it's to the nearest cent or to the nearest five cents. Sometimes you win a tiny bit, and sometimes you lose a tiny bit. On average it makes no difference, so long as the rounding unit is smaller than the cost of the item. And not many places keep items priced below 5c.
Okay, what if I submit a design to print a 3D gun
This problem is not specific to 3D printers. Just ask Sheffield Forgemasters, who famously made an "oil pipe" for Iraq back in 1990. Oddly, the pipe was enormously strong and specified to very fine tolerances. Turns out it wasn't for oil.
What about the nasty isotopes which didn't come from "that old thing"? Don't you worry about those? That's my point.
Chernobyl was a horrific design even by the standards of the time. Modern designs are immune to the kinds of accidents which happened at Three Mile Island, Chernobyl, and even Fukushima.
Coal burning also releases more radiation than nuclear power does. If the same safety rules were applied equally to both types of power, nuclear would come out way ahead.
Absolutely. And tinkering pretty much requires a keyboard, so the majority of Android or iOS devices are physically unsuitable for that kind of use. Carry a laptop when you need it and a tablet when you don't. I can see the attraction of a slim, light tablet device when you just need to check emails or buy tickets, and although the prices seem rather high for such simple devices it's obvious that people are happy to pay. But no matter how good these tablets get there will always be tasks which need a better (and bigger) human interface, and that's where PCs are unbeatable.
The ITER project has an overly complex management for purely political reasons, and that causes complexities, delays and increased costs.
Sure, but that's the nature of huge projects. They require huge amounts of money from numerous sources, and each source wants to make damn sure they get something in return for their investment. Could a more efficient management structure be imagined? Maybe. Could it ever actually be implemented? No.
However the managers think everything is fine.
They say everything is fine because if they don't the investors will lose confidence and the project will collapse. The actual lack of fine-ness causes many headaches for the scientists and engineers who have to deal with unrealistic planning, but somehow they usually find a solution. Think of it this way: the managers say what they say because they have more faith in their staff than they do in the politicians funding the project.
If Bill Gates really wanted to help the world, he'd take $30 Billion and make it a prize for whoever can get an operation fusion reactor running
But you need the money before you start. Nobody would invest billions entering such a competition on the off-chance they might get their money back.
I think we really are skirting the boundary between physics and philosophy.
There's a boundary?
If the risk was obvious, I would agree. However I'm not sure that one's vulnerability when cycling is really appreciated - just as people didn't used to feel vulnerable when driving without seatbelts. Even a minor fall onto hard pavement can easily break bones, and if the broken bone happens to be the skull then you can be in real trouble.
A little while ago I took a tumble when a startled animal ran into my bike. I landed on my helmet, which cracked, and was dazed enough to earn a day in hospital. Later, when a road safety group visited my workplace, I got a chance to find out roughly what kind of impact I had taken. They took the remains of my helmet and hit it with a hammer on an undamaged area until it showed damage similar to the original fall. It required quite a serious blow with a heavy hammer. They then delivered a similar blow to a force-measuring stand, which indicated that the force delivered was far more than that needed to break a skull.
In short, even on an empty country lane an unlucky fall can kill you. Until recently I didn't know that, and I suspect lots of other people don't know it either.
The grade of the helium is entirely irrelevant. The helium used to cool superconducting MRI magnets is recycled over and over: it doesn't wear out, and impurities are automatically removed during the liquefaction process. Wasting "old" helium is just as bad as wasting fresh.
Just because you're a "spy" doesn't mean you're not in a group of plane-spotters that plan a trip to Greece. Hell, sounds like a perfect persona to assume to me.
Put yourself in the shoes of the spy. Your choices are
Plan A: be conspicuous. Run a high risk of being stopped, but have a story and hope you can bluff your way out.
Plan B: be discrete. Try to avoid being stopped, although if you are caught you are doomed.
Opting for Plan A means you have to infiltrate a plane-spotting group. Then you have to persuade the group to go to the base you're interested in. When you get there you can only take pictures consistent with being a plane spotter, or your cover story is blown. And when you are stopped (which is certain, because photography is forbidden), you have to hope that none of your friends mention your recent membership of the group, or your curious interest in this particular base. That takes a lot of time and work, the information you can gather is constrained, and the risk is substantial.
Plan B is far easier, doesn't suffer from the limitations of Plan A, and if you do a good job of hiding your camera the risk of being caught is low. And yes, I have read too many spy novels.
This has happened before. A group of British plane spotters were convicted of spying and sentenced to 3 years in jail. It doesn't seem to have occured to the Greek military that real spies will be a little more discrete in their methods.
BBC news article
Get him a Raspberry Pi
This is the best answer so far by a mile. The Raspberry Pi has all the hackability of the 8-bit machines we grew up with, but runs a modern operating system with modern programming languages. And of course comes with plenty of games.
In addition to the usual accessories, I'd recommend getting a dedicated screen so that the RPi isn't competing with the telly for attention. Other useful things to have include a case (transparent of course), a powered USB hub (for WiFi and storing data to USB keys) and a spare SD card with the OS installed on it. If he's interested in electronics, look out for the recently released "Gertboard" interface - it's more electrically robust than connecting directly to the RPi. And books. Lots of books, on paper.
...In other unrelated news, when I had tuberculosis all the restaurants in my area kicked me out
The trouble is that (following your analogy) the hospitals are inside the restaurants.
And which insurance company will insure this relatively incalculable risk, and at what price?
Premium cost = average accident rate * average accident cost + insurance company margin
It's the same formula whoever's driving, and the coefficients are worked out in the same way for robots as for humans.
would the wright brothers be expected to provide valuable input on the latest stealth bomber?
If they'd been working with aeroplane technology and keeping up with progress for the 109 years since Kitty Hawk then yes, I think they probably would have a few useful ideas.