The congestion charge has pros and cons. It seems to reduce traffic somewhat, generates money to be used for buses, and probably cuts pollution. Some argue it works too well, hurting businesses in the central zone, and some people are occasionally sent a fine for not paying the charge even though they never went near the central zone. It works by a camera trying to OCR the license plate. The recognition can go wrong, and the camera can take snaps of people who don't actually enter the zone occassionally.
Still, personally I'm in favour of it - I don't drive in London because it gets in the way of my drinking.
You're a funny man. And di-hydrogen monoxide can be lethal in large doses. However let's do some thinking...
Whilst water does absorb heat nicely, the house actually takes water out of the environment by breaking down water into hydrogen and oxygen. So, if there were lots of these houses, and on average they had some hydrogen on store, then there'd be slightly less water freely available.
Since there's already so many people without clean drinking water, this isn't going to help in those areas. For Malaysia though it's probably great - loads of sun and rain almost every day.
The point isn't to make money out of this. They're doing it to clean up the pollution. It's nice that the gold can be sold to cover costs and provide some education, but it's great that they can get the mercury out of the soil.
do you become marginally dumber when you close your eyes?
Maybe you become smarter. If you aren't using certain parts of the brain for visual signal processing and object recognition, they might be repurposed for use in abstract thinking, creative thought etc. I'm thinking of something akin to an FPGA.
One of the problems with overclocking your brain would be keeping the timings of various sections/lobes/hemispheres in sync. Dealing with clock signals is a hassle in modern CPU design, and there's probably an analogous concept in the brain.
As for the cooling system, we're very lucky to have a liquid cooling system build in - the blood circulation in your head is an important regulator, taking heat from the depths of the brain to the outer parts where it can be removed by convection/sweating. You could augment this too. Change your hair for copper filaments. Actually, then we'd all be really ginger, so better use gold. If you going to mod, do it in style eh?!
It's amazing what people think 10cm is (fnar fnar), especially if they're used to inches. 10cm is about 4 inches. I have a Shuttle XPC here on my desk. It's about 20cm by 20cm on the front, and twice that deep. I could go look up the actual figures but who cares?
Also, IIRC, a compact disc is 8cm across.
But the parent has a point about 10x8x8. That's almost a cube. Maybe it's a box containing core store:)
Although ramjets have been around for decades, they've generally been used at speeds of around Mach 1-3. The BOMARC webpage gives a good example, with a speed of just under 2000 mph. Scramjets might one day be developed to work well at around Mach 5-10, but it's been a tricky problem for engineers to solve.
Scramjet combustion is tricky because the fast air flow can easily blow out the flame. Imagine blowing gently on a small match flame to increase the flame versus blowing strongly on a candle flame to put it out.
Also the shape of the scramjet generally favours a "sweet-spot" in air pressure (altitude) and speed. This makes them OK for cruise missiles, but not so good for orbital launch rockets. You can try variable geometry (change the shape of the inlet/nozzle) but that means some machinery, which adds weight to the system.
That brings me onto another problem - thrust/weight ratio. Rocket engines get much higher thrust/weight ratios than air breathing engines. The best air-breathing thrust-weight design that I've seen is Skylon's SABRE (not a ramjet) which will be nice if they can ever build it.
Unobtainium - air-breathing rockets
on
The Wrong Stuff
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· Score: 1
I disagree about Skylon, because although it's engine (http://www.reactionengines.co.uk/main.php?content =sabre) seems very nice and clever, it is probably quite difficult to implement. The idea of cooling air down and then pumping it into a combustion chamber is great, but is likely to suffer from the problems of dust and condensed water and carbon dioxide in the 'plumbing'. Maybe they need to pump in lots of anti-freeze?!
I also look forward to dramatically cheaper launch technology, but they many problems. For instance (Sc)ramjets' thrust/weight ratio sucks, and who's going to make all those nanotubes for the space elevator?
Anyone who has a solution, please post it so I can steal the idea and become an interplanetary shipping magnate. Ta.
I suspect the biggest growers amongst languages are going to be Hindi, Arabic, and Spanish. Chinese is huge already, but hardly has a unified 1 billion speakers with dialects like Mandarin, Cantonese, Szechuan, and all your other favourite flavours;). It's possible that English will lose ground to these soon.
"Well, after all, it's hardly rocket science is it?"
But seriously, these people are sending perhaps 1000kg (3 people + capsule) to 100km. They are *not* going into orbit. The "delta-vee" they need is a small fraction (1/10 at a guestimate?) of that needed to reach Low Earth Orbit. And still it might kill them - they've got guts and they want to prove it.
IMHO 'they' lay off a selection of people, based on (in no particular order):
1) Who they think they're going to be able to generate revenue from in the future, 2) Which personalities they like, 3) How much a person costs to keep, 4) A suitable number of token managers to keep the troops happy (approx. 1 chief per 15 indians, no racial discrimination implied).
I have to agree. It's not an electromagnetic force field. It's a confined plasma which happens to be able to stop small molecules at approx. room temperature from passing through.
I suspect you could beam a laser through it, push something solid through it (no, not your hand, that's asking for pain, see other posts), or perhaps fire a beam of highly accelerated particles through it (depends on mag. field strength). So, no Star Trek shields then to fend off the space aliens just as soon as SETI contacts them to tell them we're here. That said, you might be able to consider it similar to the Enterprise NX-01 hull plating? It's all fiction;)
Finally, if Columbia had this, would it be enough to have patched the leak in the wing? I'm not sure how the plasma would perform at re-entry speeds.
The problem with air-breathing propulsion at high speeds is that to get thrust you need to take the incoming air and squirt it out the back hotter and faster than it came in. When the air is already moving at (say) 6+ times the speed of sound (SCRAMJETs), it's not actually easy to get the fuel to burn well enough to provide the thrust you want.
If there was something clever and easy that was better than a conventional rocket, I'm confident someone would do it already. Things like aerospikes could actually be pioneered in India and the far east. These improvements may only add a few % specific impulse, but on a launch cost of $100 million+ that's going to count.
You can also get more efficient (i.e. needs less fuel mass at launch, or allows more cargo) rockets if you use some funny propellants; hydrides of boron, berrylium, lithium, aluminium and the like, reacting with fluorine for example. But the fuel's very nasty to handle, which pushes up other costs.
However there's not much choice since much web (and other) software development seems driven by a high priority need to have new content, exciting developments, and enhanced features. If you have a stable system, then introducing any changes can have unforeseen consequences, especially if it's a particularly large and complex system.
The article blames developers for Monday morning bugs, and it's right. If I change some code and deploy it to the live server that I work on, then it is my fault if it breaks something (and yes I have done it on occassion). However this shouldn't be the case. Inspiration that I have on Monday night should be no more likely to cause problems than ideas I have over the weekend. In both cases any code changes should be deployed to a staging server and run through a test suite.
If the ratio of bugs to changes is higher on a Monday morning, then this is a problem - developers are not following quality control or change control processes on Monday mornings. That would be an interesting finding. On the other hand, if the ratio's the same, then more bugs just means more changes are made on Monday mornings. And you could argue that that implies a higher level of productivity!
If any Project Managers out there have statistics on this sort of thing - please post and let us know!
Do Oracle use Star/OpenOffice? I suspect not, so let's see him put his money (or not money, because Star Office is surely cheaper?) where his mouth is and switch his company's desktops over to StarOffice.
Though this isn't directly Apache related, one more aspect of scalability is code flexibility and ease of change.
Don't be short-termist just because the person generating the business requirements thinks like that. After you're up and running, things may still change. By using good design patterns you'll find it easier to add new functionality or change the system behaviour.
I'm a little disappointed to not see more concern about the huge environmental problem this implies. I have enough guilt about all those damn AOL CDs - at least my CD writer's now burnproof.
Does anyone know if there's anything recyclable in these cheap convenient plastic discs?
I recall a number of stories (quick Google search returned this Guardian link) about modifying viruses IRL to cure real diseases. What you're talking about is a digital equivalent. Of course the real world viruses don't spread from body to body through the air (far too dangerous), so to maintain the analogy, you have to choose which digital doctor you'll allow to inject you with a computer virus. Can you imagine a Mad Doc McGates? *shudder* Hold on, this is just like downloading a virus update file... oh well.
You rightly say that opto-electonics has problems. It would consume power and silicon "real-estate", much like analogue-digital (and vice versa) converters.
But there are a few tempting pluses that make an optical bus worth considering :
1) Potential to reduce clock skew. Distributing a uniform and reliable system clock is getting increasingly difficult as the MHz creep up.
2) No signal leakage. An optically isolated (covered in plastic:) line doesn't interfere with other data lines. Electronics suffer nasty capacitance and cross-talk problems at higher frequencies.
3) Mutliplexing could let you run in parallel. Modern fibres use wavelength and frequency division multiplexing. I have no idea how well this would work over short distances. Conversion lag times might make it pointless, but multiple signals on multiple bus lines would be neat, if wierd.
BTW. I found this link to a Xerox page. I have no idea what that Real Video presentation is saying - looks cool, but it's all in Japanese I think.
However, despite those 3 points, I agree that we won't see optical bus technology soon. I heard a rumour that Sun's Serengeti stuff would be optical but have heard no further mention of it since. I guess the technology issues are too great at the moment and it's the opto-electronic conversion that appears to be the killer.
I agree sort of. For simple templated pages with no user feedback it'll work fine. But remember/. is moderated, so part of the workflow procedure could automatically calculate a new checksum for content that passes moderation.
If it's a an Apache server module (mod_tripwire?) then potentially a redirect URL could be coded into the DSO. Makes it harder to change via a hack (not very hard though), but also harder to admin (though how often are you going to change the Tripwire redir URL huh?). Something like Tripwire for Apache would at worst add an extra layer of obfuscation. At best it could cut out a few more script kiddies.
Hmm, just thought, this is begging to be written as a servlet 2.3 filter... 'scuse me I'll be right back...
My brother (27, I'm 24) got me this book for my last birthday after listening to me whine about the same problems over and over. It's The 48 Laws of Power - beautifully written and a bit like an O'Reilly book for politics (hmm... there's an idea - "Politics in a Nutshell":)
It seems to come down to this. You're almost certainly more up to date with technology, but you have to kiss ass, like it or not. A good starting point for me is to always make it a multiple choice, where one answer was blatantly cheaper, quicker, and more fun for me.
Also, same as/. forces us to preview these posts, repeat in your head the thing you are about to say, just in case;)
Good luck!
Gas clouds in deep space?
on
Stop, Light.
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· Score: 1
I'm guessing it has to be such as low temperature to keep the atoms/ions from moving about too much.
If so could you find similar conditions in deep space? Assuming you could find a cloud of rubidium or sodium atoms, would they trap or slow any incoming photons? I guess it would only work with atoms, not molecules. Perhaps helium, but I don't know what wavelength of radiation would work.
I'm not sure that it would have any practical use or exciting properties, but a ridiculously far fatched possibility is that an intelligent gas-cloud organism could evolve in deep space, with an optical "nervous system". Now there's a ST Voyager plot if I ever heard one !:)
Slashdot Mirror
Parking meters in London
London Congestion Charge
The congestion charge has pros and cons. It seems to reduce traffic somewhat, generates money to be used for buses, and probably cuts pollution. Some argue it works too well, hurting businesses in the central zone, and some people are occasionally sent a fine for not paying the charge even though they never went near the central zone. It works by a camera trying to OCR the license plate. The recognition can go wrong, and the camera can take snaps of people who don't actually enter the zone occassionally.
Still, personally I'm in favour of it - I don't drive in London because it gets in the way of my drinking.
Whilst water does absorb heat nicely, the house actually takes water out of the environment by breaking down water into hydrogen and oxygen. So, if there were lots of these houses, and on average they had some hydrogen on store, then there'd be slightly less water freely available.
Since there's already so many people without clean drinking water, this isn't going to help in those areas. For Malaysia though it's probably great - loads of sun and rain almost every day.
There's a serious point though. It's possible that you can't run a modern economy based largely on tertiary industry (services).
The point isn't to make money out of this. They're doing it to clean up the pollution. It's nice that the gold can be sold to cover costs and provide some education, but it's great that they can get the mercury out of the soil.
Maybe you become smarter. If you aren't using certain parts of the brain for visual signal processing and object recognition, they might be repurposed for use in abstract thinking, creative thought etc. I'm thinking of something akin to an FPGA.
As for the cooling system, we're very lucky to have a liquid cooling system build in - the blood circulation in your head is an important regulator, taking heat from the depths of the brain to the outer parts where it can be removed by convection/sweating. You could augment this too. Change your hair for copper filaments. Actually, then we'd all be really ginger, so better use gold. If you going to mod, do it in style eh?!
Also, IIRC, a compact disc is 8cm across.
But the parent has a point about 10x8x8. That's almost a cube. Maybe it's a box containing core store :)
Although ramjets have been around for decades, they've generally been used at speeds of around Mach 1-3. The BOMARC webpage gives a good example, with a speed of just under 2000 mph. Scramjets might one day be developed to work well at around Mach 5-10, but it's been a tricky problem for engineers to solve.
Scramjet combustion is tricky because the fast air flow can easily blow out the flame. Imagine blowing gently on a small match flame to increase the flame versus blowing strongly on a candle flame to put it out.
Also the shape of the scramjet generally favours a "sweet-spot" in air pressure (altitude) and speed. This makes them OK for cruise missiles, but not so good for orbital launch rockets. You can try variable geometry (change the shape of the inlet/nozzle) but that means some machinery, which adds weight to the system.
That brings me onto another problem - thrust/weight ratio. Rocket engines get much higher thrust/weight ratios than air breathing engines. The best air-breathing thrust-weight design that I've seen is Skylon's SABRE (not a ramjet) which will be nice if they can ever build it.
I disagree about Skylon, because although it's engine (http://www.reactionengines.co.uk/main.php?content =sabre) seems very nice and clever, it is probably quite difficult to implement. The idea of cooling air down and then pumping it into a combustion chamber is great, but is likely to suffer from the problems of dust and condensed water and carbon dioxide in the 'plumbing'. Maybe they need to pump in lots of anti-freeze?!
I also look forward to dramatically cheaper launch technology, but they many problems. For instance (Sc)ramjets' thrust/weight ratio sucks, and who's going to make all those nanotubes for the space elevator?
Anyone who has a solution, please post it so I can steal the idea and become an interplanetary shipping magnate. Ta.
I suspect the biggest growers amongst languages are going to be Hindi, Arabic, and Spanish. Chinese is huge already, but hardly has a unified 1 billion speakers with dialects like Mandarin, Cantonese, Szechuan, and all your other favourite flavours ;). It's possible that English will lose ground to these soon.
"Well, after all, it's hardly rocket science is it?"
But seriously, these people are sending perhaps 1000kg (3 people + capsule) to 100km. They are *not* going into orbit. The "delta-vee" they need is a small fraction (1/10 at a guestimate?) of that needed to reach Low Earth Orbit. And still it might kill them - they've got guts and they want to prove it.
IMHO 'they' lay off a selection of people, based on (in no particular order):
1) Who they think they're going to be able to generate revenue from in the future,
2) Which personalities they like,
3) How much a person costs to keep,
4) A suitable number of token managers to keep the troops happy (approx. 1 chief per 15 indians, no racial discrimination implied).
I have to agree. It's not an electromagnetic force field. It's a confined plasma which happens to be able to stop small molecules at approx. room temperature from passing through.
;)
I suspect you could beam a laser through it, push something solid through it (no, not your hand, that's asking for pain, see other posts), or perhaps fire a beam of highly accelerated particles through it (depends on mag. field strength). So, no Star Trek shields then to fend off the space aliens just as soon as SETI contacts them to tell them we're here. That said, you might be able to consider it similar to the Enterprise NX-01 hull plating? It's all fiction
Finally, if Columbia had this, would it be enough to have patched the leak in the wing? I'm not sure how the plasma would perform at re-entry speeds.
The problem with air-breathing propulsion at high speeds is that to get thrust you need to take the incoming air and squirt it out the back hotter and faster than it came in. When the air is already moving at (say) 6+ times the speed of sound (SCRAMJETs), it's not actually easy to get the fuel to burn well enough to provide the thrust you want.
If there was something clever and easy that was better than a conventional rocket, I'm confident someone would do it already. Things like aerospikes could actually be pioneered in India and the far east. These improvements may only add a few % specific impulse, but on a launch cost of $100 million+ that's going to count.
You can also get more efficient (i.e. needs less fuel mass at launch, or allows more cargo) rockets if you use some funny propellants; hydrides of boron, berrylium, lithium, aluminium and the like, reacting with fluorine for example. But the fuel's very nasty to handle, which pushes up other costs.
Anyway, what the hell are you software developers doing thinking about work at the weekend?
Stop it now. Go out. Yes, outside. Have some fun!
If it ain't broke, don't fix it.
However there's not much choice since much web (and other) software development seems driven by a high priority need to have new content, exciting developments, and enhanced features. If you have a stable system, then introducing any changes can have unforeseen consequences, especially if it's a particularly large and complex system.
The article blames developers for Monday morning bugs, and it's right. If I change some code and deploy it to the live server that I work on, then it is my fault if it breaks something (and yes I have done it on occassion). However this shouldn't be the case. Inspiration that I have on Monday night should be no more likely to cause problems than ideas I have over the weekend. In both cases any code changes should be deployed to a staging server and run through a test suite.
If the ratio of bugs to changes is higher on a Monday morning, then this is a problem - developers are not following quality control or change control processes on Monday mornings. That would be an interesting finding. On the other hand, if the ratio's the same, then more bugs just means more changes are made on Monday mornings. And you could argue that that implies a higher level of productivity!
If any Project Managers out there have statistics on this sort of thing - please post and let us know!
Bah.
Do Oracle use Star/OpenOffice? I suspect not, so let's see him put his money (or not money, because Star Office is surely cheaper?) where his mouth is and switch his company's desktops over to StarOffice.
Though this isn't directly Apache related, one more aspect of scalability is code flexibility and ease of change.
Don't be short-termist just because the person generating the business requirements thinks like that. After you're up and running, things may still change. By using good design patterns you'll find it easier to add new functionality or change the system behaviour.
I'm a little disappointed to not see more concern about the huge environmental problem this implies. I have enough guilt about all those damn AOL CDs - at least my CD writer's now burnproof.
Does anyone know if there's anything recyclable in these cheap convenient plastic discs?
Some people seem to run Linux on S/390's. There's a bunch of case studies here on IBM's website.
I recall a number of stories (quick Google search returned this Guardian link) about modifying viruses IRL to cure real diseases. What you're talking about is a digital equivalent. Of course the real world viruses don't spread from body to body through the air (far too dangerous), so to maintain the analogy, you have to choose which digital doctor you'll allow to inject you with a computer virus. Can you imagine a Mad Doc McGates? *shudder* Hold on, this is just like downloading a virus update file... oh well.
You rightly say that opto-electonics has problems. It would consume power and silicon "real-estate", much like analogue-digital (and vice versa) converters.
:) line doesn't interfere with other data lines. Electronics suffer nasty capacitance and cross-talk problems at higher frequencies.
:(
But there are a few tempting pluses that make an optical bus worth considering :
1) Potential to reduce clock skew. Distributing a uniform and reliable system clock is getting increasingly difficult as the MHz creep up.
2) No signal leakage. An optically isolated (covered in plastic
3) Mutliplexing could let you run in parallel. Modern fibres use wavelength and frequency division multiplexing. I have no idea how well this would work over short distances. Conversion lag times might make it pointless, but multiple signals on multiple bus lines would be neat, if wierd.
BTW. I found this link to a Xerox page. I have no idea what that Real Video presentation is saying - looks cool, but it's all in Japanese I think.
However, despite those 3 points, I agree that we won't see optical bus technology soon. I heard a rumour that Sun's Serengeti stuff would be optical but have heard no further mention of it since. I guess the technology issues are too great at the moment and it's the opto-electronic conversion that appears to be the killer.
So no iso-linear chips for a decade yet I guess
I agree sort of. For simple templated pages with no user feedback it'll work fine. But remember /. is moderated, so part of the workflow procedure could automatically calculate a new checksum for content that passes moderation.
If it's a an Apache server module (mod_tripwire?) then potentially a redirect URL could be coded into the DSO. Makes it harder to change via a hack (not very hard though), but also harder to admin (though how often are you going to change the Tripwire redir URL huh?). Something like Tripwire for Apache would at worst add an extra layer of obfuscation. At best it could cut out a few more script kiddies.
Hmm, just thought, this is begging to be written as a servlet 2.3 filter... 'scuse me I'll be right back...
My brother (27, I'm 24) got me this book for my last birthday after listening to me whine about the same problems over and over. It's The 48 Laws of Power - beautifully written and a bit like an O'Reilly book for politics (hmm... there's an idea - "Politics in a Nutshell" :)
/. forces us to preview these posts, repeat in your head the thing you are about to say, just in case ;)
It seems to come down to this. You're almost certainly more up to date with technology, but you have to kiss ass, like it or not. A good starting point for me is to always make it a multiple choice, where one answer was blatantly cheaper, quicker, and more fun for me.
Also, same as
Good luck!
I'm guessing it has to be such as low temperature to keep the atoms/ions from moving about too much.
:)
If so could you find similar conditions in deep space? Assuming you could find a cloud of rubidium or sodium atoms, would they trap or slow any incoming photons? I guess it would only work with atoms, not molecules. Perhaps helium, but I don't know what wavelength of radiation would work.
I'm not sure that it would have any practical use or exciting properties, but a ridiculously far fatched possibility is that an intelligent gas-cloud organism could evolve in deep space, with an optical "nervous system". Now there's a ST Voyager plot if I ever heard one !