ah bugger. i came from google news and was wondering why my comments weren't appearing. Then I change browser and submit again. Then I check the date and the timezone. Then I track down the story from the front page and see multiple copies of all my comments:-/
Almost - it is about decreasing the amount of dark fibre, but this advance isn't an optical switch (which is some way off), this is a new advance in optical time division demultiplexing. 64 x 10Gbit/s signals were sent down a fibre. 640Gbit/s is too fast for electronics to handle, but 10Gbit/s is manageable. These researchers were able to pluck out any of the 64 10Gbit/s signals into another fibre to be processed by electronics, without destroying the other 63.
There's no journal paper on this yet - it was a postdeadline paper presented at a conference on Wednesday. It was actually done by researchers in Denmark and China, with a waveguide provided by CUDOS (CUDOS does not have a 640Gbps source). The conference paper cites a paper by CUDOS doing similar things with similar waveguides to demultiplex a 160Gbps signal - Pelusi et al, Photon. Technol. Lett., 19 (2007), p. 1496
It actually uses four wave mixing, not the kerr effect.
Almost - it is about decreasing the amount of dark fibre, but this advance isn't an optical switch (which is some way off), this is a new advance in optical time division demultiplexing. 64 x 10Gbit/s signals were sent down a fibre. 640Gbit/s is too fast for electronics to handle, but 10Gbit/s is manageable. These researchers were able to pluck out any of the 64 10Gbit/s signals into another fibre to be processed by electronics, without destroying the other 63.
Error-free as in "we demultiplexed a 640Gbit/s signal to 10Gbit/s without destroying it", error free as in "we didn't overclock this chip so far that it's unstable", rather than error free as in "we designed this new physical layer that guarantees that no packet will be interfered with on its way to its destination"
Yep, that's almost it. Optical switches/routing would speed everything up by a lot. But an optical router is a long way off - one of the unsolved problems is buffering light to avoid packet collisions. At the moment, light can be slowed down quite a bit (actually the record is 17 m/s - slower than a cyclist), but everyone is still working out how to store it reliably for long enough to build a router. There are other problems as well.
The advance that has been made is about time division demultiplexing - sending 64 different 10Gbit signals down a single fibre, and then being able to separate out the individual signals at the end. They've been able to separate one of these out using a 5cm long waveguide, of a new material called chalcogenide (As2 S3) which is being researched heavily at CUDOS.
This news is not the invention of the photonic chip. The photonic chip has not been around since 2005, it is not around now, and will not be around for some time. And at a conference this week, some were arguing that a digital photonic chip will never be around in a way competitive to electronics, at least with our current internet protocols. The photonic chip is a long term goal, which incorporates most of CUDOS's research, but the advance announced here would be one small component of the chip (or useful on its own)
The news here is that people in Denmark/China have demultiplexed a 640Gbps signal (too fast for electronics to handle) into one of its constituent 10Gbps signals (which is manageable by electronics), using one of our chalcogenide waveguides. I think the previous record was 160Gbps by CUDOS last year.
This advance is at the laboratory stage - I think the experiments weren't done in Australia because we don't have a 640Gbps source, so don't expect all telcos to switch over to this technology today - but hopefully in time this will be put to use in the fibre backbone.
There was a post-deadline paper presented on this on Wednesday evening at the OECC/ACOFT conference, but I don't think there are any journal papers on it yet. Basically they used a 10Gbps pump, using four wave mixing to demultiplex a 640Gbps signal.
Put simply, there were 640x10^9 pulses (or absences of pulses) per second, and the researchers were able to select every 64th pulse. They did this by pumping the fibre with 10x10^9 pulses per second, and when these pulses overlapped with the signal pulses, the signal pulses were frequency shifted by nonlinear effects. Once frequency shifted, it was relatively easy to separate them out from the other 630x10^9 pulses.
Yep, I'm in the research group concerned. It was pretty funny to look at the ways in which this story was distorted and Eggleton's soundbites were distorted.
He was talking about two things: a) This new advance, which is about being able to pull a 10Gbps signal out of 64 time-division multiplexed 10Gbps signals (and was actually done by a group in Denmark/China, with one of our waveguides. b) The Photonic Chip, which is our long-term goal, of all-optical signal processing (e.g. an optical router).
OK, I would have thought that the cost of production of a disc in a packet would be less than 10c - I can buy 100 DVD-Rs at retail for 22c per disc, so I expect the manufacturing cost of a non-rewritable disc covered in this 'magic adhesive' would be smaller. (I'm assuming it's packaged in cheap packaging, e.g. airtight foil).
So by this analysis it costs at least 10 times as much to buy a litre of fuel as it does to produce the disc. But the manufacturing plant would not be running off a petrol generator - they would be using a cheaper (and more efficient, but not necessarily by the same factor as the price difference) form of energy, so it gets complicated.
To be honest, and to paraphrase Colbert, I looked it up in my gut. I didn't notice anyone else considering the environmental impact of the drive to the video store, so I thought it deserved to be included in the equation.
Quantifying "environmental damage" is hard - do you consider impact on landfill (flexdisk loses) or just CO2 footprint, or some weighting of many factors? My gut told me that the CO2 footprint of mass-pressing one of these disks would be rather small compared to the drive to the video store - my gut told me that mass-produced DVDs are economically cheap to make, whereas a consumer's car trip is more expensive by an order of magnitude or two, and that environmental damage couldn't be an order of magnitude or two cheaper for a company mass-producing DVDs. My gut is often wrong.
A car might burn 1L of fuel going to and from the video store (5km away), releasing >2kg of CO2. I honestly don't know how much energy it takes to make one DVD, but I sincerely hope the process would release less than 2kg of CO2 per disc!
If you have any information that goes against the word of my gut, my oesophagus would be glad to swallow it!
The environmental damage from creating/disposing of the self-destructing DVD is probably actually less than that from driving to the video store to return it.
It is "Facebook will not sell your data" in bold letters. They also have fine grained controls for how much of your profile your friends/your 'friends' and your fellow network members can see. As people outside your networks can not see your profile at all, there is an illusion of privacy. What you have little control over (and the control is fairly well hidden) is the data that your FRIENDS' applications can see on your account. I think there is a clause in the developer code of conduct that apps aren't allowed to store profile data, but that doesn't sound too enforceable.
Basically you have privacy from other end users, but not from applications. You only experience facebook as an end user, so you might expect to have privacy in general. But this is not the case.
Nup. The really cool thing about this device (for the light cloaking devices that have been built, anyway) is that you don't block the noise behind the submarine. However as I commented below, I don't think these devices would hide the noise of the submarine or whatever was within the cloak, they would just allow sound to pass through the cloaked submarine as if the submarine was not there. The other problem is that these cloaks only work for a limited frequency range.
The devices the article talks about are not what you want from a cone of silence. What the researchers are proposing is something that will hide an object from external noises - as in the object will not affect any sound waves heading towards it, they will just pass straight through as if the object and cloaking device were not there. The proposed device WILL NOT contain noise created by whatever you're trying to hide, so the bad guys can still listen for a submarine's engines, they just won't be able to use active sonar to find the submarine.
If you want a cone of silence, then you put yourself in a noise isolation chamber. Or if you want something cooler, then you put yourself in the acoustic equivalent of a gap-defect photonic crystal, which is a series of cylindrical rods arranged in a hexagonal lattice with one removed. A particular wavelength of sound will be reflected by this lattice, so if you're in the middle of that gap and you sing at that frequency, no-one outside the lattice will be able to hear you. Of course, you will very quickly become deaf because the sound is all reflected within the defect rather than absorbed, so the noise from your singing builds up.
I think the exciting thing here is that an object's acoustic shape could be tailored and even made smaller by surrounding it by another material. The more fundamental thing here is that we can have a whole lot of new and interesting "media" that sound can propagate through, and possibly (if this is like photonics) media where sound travels "backwards".
It seems they're importing ideas from photonics and metamaterials - light and sound, they're all waves. What's been done with light (in Britain and Germany IIRC) is some object has been surrounded by a 'cloaking device', and for one specific wavelength of light, the cloaking device and object become completely transparent and invisible. Light flows through the cloaking device and around the object that's being hidden (well that's the hand-wavy explanation).
To do funky stuff like cloaking, you need (in optics) a material with negative refractive index (so light seems to travel backwards). People get this by arranging tiny (smaller than the wavelength of light involved) resonators in a regular pattern. The light wave "doesn't see" the individual resonators, but instead "sees" an overall medium. However, this medium can have quite abnormal properties (such as negative refractive index).
Another way of looking at the device is that you surround the object with resonators that specifically cancel out any effect on the sound/light wave that the object makes. So you get no net effect on the wave, so it's as if the object wasn't there.
Presumably the people at Duke have transplanted some designs for light and have worked through the corresponding acoustic wave equations to find "negative refractive index sound" (though i'm not sure what their resonators would look like, because light is more complicated than sound and most light metamaterial designs use properties of both E and H components of light. Maybe they can cheat because sound travels faster in, say, wood than air)
There was at least one unreasonable paragraph in there:
Despite current EU regulations being the most stringent in the world, these regulations do not cover all kinds of hazardous chemicals, including all BFRs. It is surely reasonable to expect that an industry which prides itself on innovation should be well ahead of the curve on issues as fundamental as the use of hazardous substances.
1) Even dihydrogen-monoxide is toxic in large enough quantities. Everything is hazardous to some extent, and we just have to live with it - is it better to focus on eliminating hazardous chemicals instead of, say, decreasing power consumption? Depends on how hazardous the chemicals are.
2) Cutting edge industries traditionally are environmentally unfriendly - first you get the damn thing to work, then you get it to work cleanly, efficiently, and cheaply.
their FAQ says 70%. And they'll be on the watch for lobby groups manipulating results, unless there are over 100,000 votes cast for that piece of legislation (which will almost never happen). There's some space for them to stuff it up in the implementation, but this could be a lot worse.
No, actually! According to their FAQ they're only running for the Senate, our house of review. So they won't be proposing any bills and effectively give the public a veto. Looks surprisingly well done
The FA said "water mark". Have you read somewhere that the info is just in an ID tag and not encoded in the stream some way? Yes. And supposedly passing the file through most audio editors (including one, IIRC by Rogue Amoeba, that losslessly edits the file) will destroy the ID tags (and presumably the "sign" and "chtb" fields).
No textmate either! It certainly does everything the journo wants from BBEdit. And for LaTeX and Ruby it's utterly indispensable. I think it's the only shareware I've ever bought.
Slashdot Mirror
ah bugger. i came from google news and was wondering why my comments weren't appearing. Then I change browser and submit again. Then I check the date and the timezone. Then I track down the story from the front page and see multiple copies of all my comments :-/
Almost - it is about decreasing the amount of dark fibre, but this advance isn't an optical switch (which is some way off), this is a new advance in optical time division demultiplexing. 64 x 10Gbit/s signals were sent down a fibre. 640Gbit/s is too fast for electronics to handle, but 10Gbit/s is manageable. These researchers were able to pluck out any of the 64 10Gbit/s signals into another fibre to be processed by electronics, without destroying the other 63.
There's no journal paper on this yet - it was a postdeadline paper presented at a conference on Wednesday. It was actually done by researchers in Denmark and China, with a waveguide provided by CUDOS (CUDOS does not have a 640Gbps source). The conference paper cites a paper by CUDOS doing similar things with similar waveguides to demultiplex a 160Gbps signal - Pelusi et al, Photon. Technol. Lett., 19 (2007), p. 1496
It actually uses four wave mixing, not the kerr effect.
Almost - it is about decreasing the amount of dark fibre, but this advance isn't an optical switch (which is some way off), this is a new advance in optical time division demultiplexing. 64 x 10Gbit/s signals were sent down a fibre. 640Gbit/s is too fast for electronics to handle, but 10Gbit/s is manageable. These researchers were able to pluck out any of the 64 10Gbit/s signals into another fibre to be processed by electronics, without destroying the other 63.
Error-free as in "we demultiplexed a 640Gbit/s signal to 10Gbit/s without destroying it", error free as in "we didn't overclock this chip so far that it's unstable", rather than error free as in "we designed this new physical layer that guarantees that no packet will be interfered with on its way to its destination"
Yep, that's almost it. Optical switches/routing would speed everything up by a lot. But an optical router is a long way off - one of the unsolved problems is buffering light to avoid packet collisions. At the moment, light can be slowed down quite a bit (actually the record is 17 m/s - slower than a cyclist), but everyone is still working out how to store it reliably for long enough to build a router. There are other problems as well.
The advance that has been made is about time division demultiplexing - sending 64 different 10Gbit signals down a single fibre, and then being able to separate out the individual signals at the end. They've been able to separate one of these out using a 5cm long waveguide, of a new material called chalcogenide (As2 S3) which is being researched heavily at CUDOS.
This news is not the invention of the photonic chip. The photonic chip has not been around since 2005, it is not around now, and will not be around for some time. And at a conference this week, some were arguing that a digital photonic chip will never be around in a way competitive to electronics, at least with our current internet protocols. The photonic chip is a long term goal, which incorporates most of CUDOS's research, but the advance announced here would be one small component of the chip (or useful on its own)
The news here is that people in Denmark/China have demultiplexed a 640Gbps signal (too fast for electronics to handle) into one of its constituent 10Gbps signals (which is manageable by electronics), using one of our chalcogenide waveguides. I think the previous record was 160Gbps by CUDOS last year.
This advance is at the laboratory stage - I think the experiments weren't done in Australia because we don't have a 640Gbps source, so don't expect all telcos to switch over to this technology today - but hopefully in time this will be put to use in the fibre backbone.
There was a post-deadline paper presented on this on Wednesday evening at the OECC/ACOFT conference, but I don't think there are any journal papers on it yet. Basically they used a 10Gbps pump, using four wave mixing to demultiplex a 640Gbps signal.
Put simply, there were 640x10^9 pulses (or absences of pulses) per second, and the researchers were able to select every 64th pulse. They did this by pumping the fibre with 10x10^9 pulses per second, and when these pulses overlapped with the signal pulses, the signal pulses were frequency shifted by nonlinear effects. Once frequency shifted, it was relatively easy to separate them out from the other 630x10^9 pulses.
Yep, I'm in the research group concerned. It was pretty funny to look at the ways in which this story was distorted and Eggleton's soundbites were distorted.
He was talking about two things:
a) This new advance, which is about being able to pull a 10Gbps signal out of 64 time-division multiplexed 10Gbps signals (and was actually done by a group in Denmark/China, with one of our waveguides.
b) The Photonic Chip, which is our long-term goal, of all-optical signal processing (e.g. an optical router).
OK, I would have thought that the cost of production of a disc in a packet would be less than 10c - I can buy 100 DVD-Rs at retail for 22c per disc, so I expect the manufacturing cost of a non-rewritable disc covered in this 'magic adhesive' would be smaller. (I'm assuming it's packaged in cheap packaging, e.g. airtight foil).
So by this analysis it costs at least 10 times as much to buy a litre of fuel as it does to produce the disc. But the manufacturing plant would not be running off a petrol generator - they would be using a cheaper (and more efficient, but not necessarily by the same factor as the price difference) form of energy, so it gets complicated.
To be honest, and to paraphrase Colbert, I looked it up in my gut. I didn't notice anyone else considering the environmental impact of the drive to the video store, so I thought it deserved to be included in the equation.
Quantifying "environmental damage" is hard - do you consider impact on landfill (flexdisk loses) or just CO2 footprint, or some weighting of many factors? My gut told me that the CO2 footprint of mass-pressing one of these disks would be rather small compared to the drive to the video store - my gut told me that mass-produced DVDs are economically cheap to make, whereas a consumer's car trip is more expensive by an order of magnitude or two, and that environmental damage couldn't be an order of magnitude or two cheaper for a company mass-producing DVDs. My gut is often wrong.
A car might burn 1L of fuel going to and from the video store (5km away), releasing >2kg of CO2. I honestly don't know how much energy it takes to make one DVD, but I sincerely hope the process would release less than 2kg of CO2 per disc!
If you have any information that goes against the word of my gut, my oesophagus would be glad to swallow it!
The environmental damage from creating/disposing of the self-destructing DVD is probably actually less than that from driving to the video store to return it.
It is "Facebook will not sell your data" in bold letters. They also have fine grained controls for how much of your profile your friends/your 'friends' and your fellow network members can see. As people outside your networks can not see your profile at all, there is an illusion of privacy. What you have little control over (and the control is fairly well hidden) is the data that your FRIENDS' applications can see on your account. I think there is a clause in the developer code of conduct that apps aren't allowed to store profile data, but that doesn't sound too enforceable.
Basically you have privacy from other end users, but not from applications. You only experience facebook as an end user, so you might expect to have privacy in general. But this is not the case.
Nup. The really cool thing about this device (for the light cloaking devices that have been built, anyway) is that you don't block the noise behind the submarine. However as I commented below, I don't think these devices would hide the noise of the submarine or whatever was within the cloak, they would just allow sound to pass through the cloaked submarine as if the submarine was not there. The other problem is that these cloaks only work for a limited frequency range.
The devices the article talks about are not what you want from a cone of silence. What the researchers are proposing is something that will hide an object from external noises - as in the object will not affect any sound waves heading towards it, they will just pass straight through as if the object and cloaking device were not there. The proposed device WILL NOT contain noise created by whatever you're trying to hide, so the bad guys can still listen for a submarine's engines, they just won't be able to use active sonar to find the submarine.
If you want a cone of silence, then you put yourself in a noise isolation chamber. Or if you want something cooler, then you put yourself in the acoustic equivalent of a gap-defect photonic crystal, which is a series of cylindrical rods arranged in a hexagonal lattice with one removed. A particular wavelength of sound will be reflected by this lattice, so if you're in the middle of that gap and you sing at that frequency, no-one outside the lattice will be able to hear you. Of course, you will very quickly become deaf because the sound is all reflected within the defect rather than absorbed, so the noise from your singing builds up.
I think the exciting thing here is that an object's acoustic shape could be tailored and even made smaller by surrounding it by another material. The more fundamental thing here is that we can have a whole lot of new and interesting "media" that sound can propagate through, and possibly (if this is like photonics) media where sound travels "backwards".
It seems they're importing ideas from photonics and metamaterials - light and sound, they're all waves. What's been done with light (in Britain and Germany IIRC) is some object has been surrounded by a 'cloaking device', and for one specific wavelength of light, the cloaking device and object become completely transparent and invisible. Light flows through the cloaking device and around the object that's being hidden (well that's the hand-wavy explanation). To do funky stuff like cloaking, you need (in optics) a material with negative refractive index (so light seems to travel backwards). People get this by arranging tiny (smaller than the wavelength of light involved) resonators in a regular pattern. The light wave "doesn't see" the individual resonators, but instead "sees" an overall medium. However, this medium can have quite abnormal properties (such as negative refractive index). Another way of looking at the device is that you surround the object with resonators that specifically cancel out any effect on the sound/light wave that the object makes. So you get no net effect on the wave, so it's as if the object wasn't there. Presumably the people at Duke have transplanted some designs for light and have worked through the corresponding acoustic wave equations to find "negative refractive index sound" (though i'm not sure what their resonators would look like, because light is more complicated than sound and most light metamaterial designs use properties of both E and H components of light. Maybe they can cheat because sound travels faster in, say, wood than air)
Well let's just hope they don't adopt Wikipedia's pathetic search engine...
2) Cutting edge industries traditionally are environmentally unfriendly - first you get the damn thing to work, then you get it to work cleanly, efficiently, and cheaply.
their FAQ says 70%. And they'll be on the watch for lobby groups manipulating results, unless there are over 100,000 votes cast for that piece of legislation (which will almost never happen). There's some space for them to stuff it up in the implementation, but this could be a lot worse.
No, actually! According to their FAQ they're only running for the Senate, our house of review. So they won't be proposing any bills and effectively give the public a veto. Looks surprisingly well done
I presume that what's actually going to happen is that ARIA are going to be on the Gnutella network, watching what gets downloaded by australian IPs.
But '/' looks nothing like 'a'...
No textmate either! It certainly does everything the journo wants from BBEdit. And for LaTeX and Ruby it's utterly indispensable. I think it's the only shareware I've ever bought.