I'd bet the battery life on this sucks. allegedgly Ogg is not as mathematically efficient (sucks batteries), and on top of this all the groovy ad hoc software power management tricks ipod probably does will get chucked.
The whole point of the ipod is seemless integration. Who needs ogg when you have AAC (with or without DRM).
in the future more and more things wil be tied to the web. Office applications like writely and ajaxWrite. Photo librarys. Maybe even your music and TV. You won't want to unplug to run the OS.
On the otherhand I like this solution to piracy. If it detects a piarate copy it hobbles the OS but does not shut it down. That makes it safe to use in case it glitches on you and mis-detects it's lic status.
I'd take it one step further and change the mouse to an oversized hot pink X with a desktop that says "Liscence key not valid". Anyone seeing that on someone elses computer would know it was stolen and there might be social pressure to pay for what you can steal.
It can't be hacked. It says so right in the article:
A potential security breach threat apparently doesn't exist.
"I wondered what's to prevent some nut using a garage door opener from pushing the right buttons to make your airplane fall apart," said Harrison. "But everything is locked down with codes, and the radio signals are scrambled, so this is fully secured against hackers."
I went to a demo-day for voting machines. When I got to the voting booth no one could see what I was doing. So I flipped over the machine, and removed the back panel. I yanked out the voting flash cards. put them in my pocket. Then I took them back out of my pocket and put them back into the machine. This was all done while two vendors stood 3 feet away watching just me. their was no curtain either, just the carol enclosure was sufficient to obsure their view. Not making this up.
I noticed that the next time they cam to town thie newer model which has a paper logger attached no longer fit in the voting carol, So it was mounted on a stand and this would have been slightly harder to flip upside down. On the otherhand if I were a poll worker this would not have been a problem. The places where the tags and seals attach is easily defeated since you can snap out the plastic hinges.
The point here is not that you fould not make one with a better design but that they chose not to. Just as diebold chose to use interpreted code on the ballot configuration cards that has the authority to re-write the vote files.
SO it's not that you cannot make a secure system--eventually--but that there isn't even the slightest effort to attend to some mac-truck size holes. they know they are their and they prefer to hide them in propriatary obfuscation not secure them. These are not people we can just trust because they seem nice. You have every right to be 100% skeptical because every time someone looks hard we find they are not fixed right.
Re:MUCH MUCH Much better solution
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I submitted it a few months ago. Gave them a tar file that runs the exploit. Wrote it myself. It works. It's not a programming bug that's creating a security hole but an flaw in the authentication policy design that grants persistent authentication across sessions. But I'm not saying any more.
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If you are an admin user I can get root access without knowing your password. the mac security framework is not secure. I'm not going to tell you how as it's an unpublicized existing security hole that requires a large policy change and wont likely happen for some time. But it exists. You do NOT want to work as admin all the time. you want to selectively activate admin as needed and require it to ask you a different than normal password when you do.
MUCH MUCH Much better solution
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Virtually all the tom foolery suggested inthe article is unneeded since on macs there is a better solution. Have two logins. One has admin privs and one does not. use the latter for your bussness.
While this can be terrifically painful on Linux and Windows its not painful at all on a mac. What happend is that nearly anytime you do an opertaion that requires root privledges from the gui the mac does it but first pops up an authentication box that wasks not for your everyday account password but instead your admin user password. So it's nearly seamless.
For the few cases where this wont suffice, you can either fadt user switch to admin, or you can pull up a terminal and su to the admin.
this has all the same protections the sill approach advocated in that article suggests.
Why is everyone reacting so negatively to this. It's the first step in what is fundmantelly a great idea to elimate spam. namely: Step1: anything that is not whitelisted by the receiver, and otherwise does not bear a stamp is by definition SPAM.
step2: (Not implemented yet) a universal postage system not an AOL only postage system.
What makes this great is that it can be done very seemlessly and nails the problem. If someone is willing to send you something unsolicited and pay for it then it may turn out to be junk mail but it's not a spam flood since they do have to pay for it. Right now I get junk mail in my snailMail box every day. It's annoying but it's not a flood. Occasionally I do get something interesting (e.g a better deal on DSL, an event in town, a sale at the hardware store, a buck off starbucks). But it's NOT a FLOOD. just imagine if mailing Junk mail cost nothing and printing it cost nothing. Imagine the flood that might happen in snailMail.
So we need a stamp to damp the flood. It's not that we want to elminate unsolicited e-mail. We just need to make it cost the sender a small amount.
The awkward thing about AOL is they have not done step 2.
People are tarring this iniative as though it were AOL trying to profit off of preferred spammer. That could be the case, depending on how high the fee is and who pockets it (why not let the spam recipient pocket it---open this e-mail and you could win an ipod).
But it's win-win. We need the fee to damp spam. and to the extent that AOL makes more money then it's likely they will also lower their costs of access to consumers. Or maybe they won't. Consumers might even pay extra to live in the land on minimal spam.
Move on is painting this as sinister. It's not. Moreover, this policy might needs some tweaks. for example suppose that politcal e-mail got a free pass and commercial e-mail had to pay. I'm not spammed by political e-mail yet since it would backfire.
AOL may have implmented it slightly wrong but charging a postage stamp for e-mail is exactly what need to be done. We need some form of micro payment system for sending e-mail. One concept here is that the payment is only collected if the recipient marks the mail as spam, otherwise it's refunded.
The idea of charging for a resource you have already paid for in other ways or is otherwise free is an almost universally accepted concept in ecomonics as the best way, on a large scale, to avoid the trajedy of the commons. It's been noted since there were people to note it that livestock herders always overgraze public shared lands but generally they manage their own private land sustaibly. It's one of the primary arguments in favor of private property rights.
Taxes are not always about raising money. Recently it's been proposed that there be a tax on trades at stock exchanges. This would act as a damper on excessive day trading activity. (some day trading activity is good because it arbitrages the market inequity and increases liquidity, but too much increases volatility).
Sometimes this same effect can be done with a refundable deposit rather than a tax. For example, when a bank takes in a deposit of money, it in turn must give some percentage, say 10%, to the federal reserve bank to hold onto. It's not a tax since it will be given back if the investor withdraws his funds. But it has a dampening effect. The bank will now loan out 90% of the deposit to other people who will buy things and those sellers will put their money back in the bank. At the end of the day there is 10 times as much money in circulation. If the federal reserve had not taken it's witholding that cycle would multiply the amount of money in circulation indefinitely.
So taxes or deposits can be good public policy. If we could charge everyone just a small amount extra for e-mails, even if they have paid for thie ISP already it's a good thing. If we can make it refundable like a deposit system it's even better. It's no different from the fact that people who graze on public lands already paid for the lands once in their taxes, but if we charge them an extra fee per head of cattle they don't overgraze.
But there's technical problems to implementing this micro payment system which is why AOL is trying simpler systems first. But this would work even better if everyone did it not just AOL.
Which came first the symbiant or the host? One might say well the host of course. But now consider the virus and the bacteria. we are told the host may have evolved from the virus.
of course bacteria have their own virus like properties. For example, they serialize their objectes and multi-cast them to other bacteria for remote processing. Sometimes data values from that compuation. That is to say, bacteria have plasmids which a small usually circular chunks of data that are docked along side their primary dna. these plasmids are processed by the local host bacteria to get it's data and instructions. But it can also give these plasmids to other bacteria and accept them. That's how for example, antibiotic resistance is commonly propagated. The instructions for it get put on a plasmid and distibuted to other bacteria for use. thus like viruses this enable the net DNA of the host to change after birth.
In separate analogy. It's interesting to notice that like von neumann's architecture DNA intersperses data and instructions. And of course we also get buffer overflow error too where data becomes instructions. I've foundit intriguing that Von Neuman also felt this ambiguity was more powerful than separation of data and instructions. These days keeping the separate is of course a big problem in robust programming. Yet life, the ultimate robust system, does the same thing.
I beleive this is supposed to be more than multi-casting. I think Cringley was saying that Akami can't handle more than 150,000 simultanoues streams of the same stream let alone different streams. I bet they multi-cast those streams. As I read it he means that to multi-cast to 30 million folks you need to have a tree structure with each node multi-casting it's part. So now simply multi-casting is not the solution.
P2P narrowcasting so that everyone can watch their favorite show any time of day _they choose_ is like telling everyone in a crowded hot tub to move to the other side simultaneously.
p2p Broadcasting a single feed is like having everyone shift over one seat.
you get to sit next to the jet the same amount time. But you may not get to sit there when you choose.
Is there a way we can set up OS X so that certain commands (delete, for example) require a superuser?
What you are asking for specifically would be impractical since you could not change any documetns. But look up access controll lists on tiger if you want to know about fine grained control of user priv.
no I tested this as an unprivledged user and the exploit runs.
I notice that the exploit may fail if terminal.app is already running. It runs but then fails to open the calaculator.app as promised.
Nah the force issue is irrelvant. if the only thing that mattered here were the material strenght forces then you siply make the motor smaller to cahive the same torque. So that's not the point.
the key point it if there is any net gain at all. The static force analysis simply does not give the answer. As I said adding a spring would do exactly the same thing as adding a permenant magnet. But then it becomes obvious that there no net gain because the you had to pay the effort of loading the spring.
Since they rely on this static argument without giving a dynamic argument it seems like bullshit to me. My bullshit detector is further raised when they present the finite element calculation to back up the static arguments. It's a huge calaculation that backs the worng argument. this is just plane weird. it looks like a delberate attempt to inject bamboozle ment into it. Do they know what the hell they are talking about? Then where's the dynamic analysis?
As I understand it, the claim of above unity energy utilization in the articel summary is (of course) false and not being made for this motor.
What they are saying is above unity torque production. And here unity simply means the ratio with respect to a particular arbiratrily chosen standard. It's not a magic number. Just a way to avoid using units in the discussion.
Now what appears to be happeing is that if the rotor were stopped and one measured the torque on the rotor (or linear actuator) then you would find that this force was four times as high as a motor without the parallel path technology, running at the same current and the same number of windings.
Now we can see that this is sort of misleading. If we kept the current constant and the windings constant then the force or toruqe is higher in a non-moving rotor or actuator. But in a non-moving system one can, for the same current always increase the number of windings to increase the force.
The ultimate limit comes from several practical realities. 1) increasing the windings increases both the impedance and residual reactance of the motor making it lossy and limiting it's frequency response. 2) The upper limit is reached when the magnetic flux is no longer contained by the ferrite. Both motors probably have a problem with #2 but the parallel path motor has fewer windings for the same level of force as a conventional motor.
Okay but that is still begging the question since were talking about non moving motor. adding in a permenant magent to boost the force is a lot like adding a spring to boos the force. You pay for it by the energy it took to load the spring.
Once this motor starts moving then one has to do a dynamic anayis to the flux collapsing as the rotor or actualtor moves is drawn into the field. What does this do the current in the motor? What does this do to it's complex impedance?
I don't actually know the answers to those questions. The static analysis is simply bogus for concluding that. But if one were to maintain the "spring" analogy then it seems like one could not possibly be getting any net gain.
what this device does seem to be doing however is to make an assymetric pull on the acutator. that is it pulls on one arm of the motor with 4 times the torque and the other arm with no torque at all. That might possibly lead so some sort of alteration in the lead-lag curve of of the phase response of the motor at different speeds. If so it might somehow make a motor with a given amount of windings and ferrite optimally usitize it's material content better.
So if there is any gain at all here I suspect it lies with this latter effect. But I cant' do the analysis to be sure.
My point was that while we associate magnetism with low power persistent memory and electronics with fast, high power memory, you are going to have to shed the desirable properties of magnetism to achieve speed. At that point you may find it as leaky and power hungry as electronics. Conversely, if you are willing to make electronics slower you can make more ideal, less leaky transistors. I was not saying that transistors in use have ideal properties, but that extrapolating current magnetic goodness to it's future applications may make it less ideal too.
Wikipedia entry for Magnetic Bubble memory. I worked on Magnetic Bubble memory at IBM san jose, and the wired article sounds like this is the nano-scale version of this with some big improvements in how they are manipualted. Back then the "bubbles" were a few microns in size. You patterns permaloy onto the surface of a magnetic material. Usually this was a long loop of almost touching chevrons or T-shaped permaloy elements. the bulk materila was polarized one direction (normal to the chip) and inversions in this formed round "bubbles" for reasons simmilar to surface tension these bubbles were stable in one size and liked to stick to the chevron. Under a polarized light microscope you could see the "bubbles" in contrast sticking to the chevrons, giving them their name due to their appearance. one bubble stuck to one chevron. and the presence or absense of a bubble on a chevron was a 1 or 0. in some fancy schema the bubbles could hold internal higher order domain structures to encode more than one bit per bubble but these were never made practical.
A rotating magnetic field transverse to the chip would cause the chevrons to act like little iron bar bagnets pulling the bubble from one side to the other. because the chevron shape is asymetric it acted like a rachet and would only move the bubble unidirectionally. If the field was strong enough the bubble would then "leap" to the next chevron. Under the microscope you saw marching "bits" moving along. so you could move all the bit patterns like a train along the tracks in a bulk matterial with one layer of passive patterning. at one point in the loop track you placed a reader and a writer. this way you had sequential access to any bit and could inject or delete bits in the train.
When the power went off the bubbles stayed put.
It never made it to market (fuji made some) because it's niche was too small. it was slower than ram but faster than a hard drive. it was cheaper than ram but more expensive than a hard drive. At the time it was denser than ram but less dense than a harddrive. Thus it's only use was as a cache between ram and harddrives and in applications where robustness and non-voltility would be valuable like high-radiation sattelites and point of sale terminals. The latter market was eaten by EAROM and then flash memory.
this new material sounds like it uses simmilar concepts but is much smaller and actually performs bubble logic. Not sure about where the clock comes from: perhaps it's still a rotatin mag fiield?
Since magnetic monopoles dont exist, you have to use magnetic dipoles or higher order moments. this translates in to macoscopic structures. It's hard to see how this could beat monopole electrons in size or group velocity. As for power consumption, it's true that magnetism can have low queiscent power consumption because of it's hysterises making it non-volatile. But you pay aprice for this when you have to switch it's state. on the other hand the ideal transistor consumes no power when it is not switching states. If you got rid of the hysteresis in magnetism to make it faster and lower power then it too will become volatile like electronics.
I can see how this could create dense active bulk storage, such as was done long ago with magnetic bubble memory. But I'm skeptical about a pure magnetic logic system beating electronics.
Public utuilities are normally regulated. The reasons for that are well established. Companies in the utility markets are not generally are not cherry pick the most profitable customers. Instead for being allowed to operate they are also required to serve the public interest in other matters. That's why you have the public access channel on cable TV , the public alert systems on radio, why rural communities have electricity, and why the power company cant simply shut off the juice to the old/infirm without certain procedures. Some of those Odious fees on your phone bill pay for things like universal 911 connectivity.
We generally strived to avoid two tierer public power or phone service in their early days. Of course deregulation did take place in the phone arena eventually did make sense but only after ubiquitous access had been achieved and was affordable.
So we have to be careful about two tiered proposals for the internet. It might be okay but it should be scrutinized from a public policy perspective not a bussiness perspective.
Congratutulations you are the first person to understand my post. Every other commentor has got hung up in knee jerk response to saying windows might be an important reason for IBM to port this to x86. The point of course was that there's lots of reasons this will happen and apple will be the beneficiary most poised to exploit it fast.
Link for AMD plus IBM on silicon on insulator technology:
Link
yes i realize this is not the same thing, but it stands to reason this will be IBM's conduit for this new technology to the 0x86 world. and thus to Apple.
One of the reasons AMD caught up with intel was IIRC they liscenced IBMs Silicon-on-insulator technology to get lower heat dissipation. If IBM once again liscences this to AMD then you will have this technology running on 0x86 instruction sets. Or conversely, if it's a world beating technology IBM may be able to persuade Intel to liscence it's 0x86 instruction sets.
No matter how fast the chip is, unless it runs 0x86 it's never going to show up in home or bussiness computers. Windows is the glue that holds that enterpise together and unless windows runs on it, people wont buy it and dell wont sell it unless there's a market.
So Apples will probably by able to access this in the new 0X86 mode. but it's not going to be just a simple processor replacement since you also will need RAM and busses that can handle the suction this processors is going to have. So motherboards are going to have to be entirely redeisnged to cope.
So this is going to be good news for apple since they are an agile hardware manufacturer that is not locked into the PC motherboard paradigm and are free to create their own firmware and software to run on radical hardware variants.
This sun charger will benefit people with short commutes much more than 10%. maybe as much as 100%. Whereas it will hardly benefit at all anyone with a long commute. Yet it's precisely the latter folks that benefit the most from pruis ownership. Moreover city drivers probably don't park their prius on the street, but rather in a sunless parking garage. So this will not affect urban pollution.
One the upside this probably works best during summer when gas prices are peaked.
Slashdot Mirror
I'd bet the battery life on this sucks. allegedgly Ogg is not as mathematically efficient (sucks batteries), and on top of this all the groovy ad hoc software power management tricks ipod probably does will get chucked.
The whole point of the ipod is seemless integration. Who needs ogg when you have AAC (with or without DRM).
in the future more and more things wil be tied to the web. Office applications like writely and ajaxWrite. Photo librarys. Maybe even your music and TV. You won't want to unplug to run the OS.
On the otherhand I like this solution to piracy. If it detects a piarate copy it hobbles the OS but does not shut it down. That makes it safe to use in case it glitches on you and mis-detects it's lic status.
I'd take it one step further and change the mouse to an oversized hot pink X with a desktop that says "Liscence key not valid". Anyone seeing that on someone elses computer would know it was stolen and there might be social pressure to pay for what you can steal.
"I wondered what's to prevent some nut using a garage door opener from pushing the right buttons to make your airplane fall apart," said Harrison. "But everything is locked down with codes, and the radio signals are scrambled, so this is fully secured against hackers."
I went to a demo-day for voting machines. When I got to the voting booth no one could see what I was doing. So I flipped over the machine, and removed the back panel. I yanked out the voting flash cards. put them in my pocket. Then I took them back out of my pocket and put them back into the machine. This was all done while two vendors stood 3 feet away watching just me. their was no curtain either, just the carol enclosure was sufficient to obsure their view.
Not making this up.
I noticed that the next time they cam to town thie newer model which has a paper logger attached no longer fit in the voting carol, So it was mounted on a stand and this would have been slightly harder to flip upside down. On the otherhand if I were a poll worker this would not have been a problem. The places where the tags and seals attach is easily defeated since you can snap out the plastic hinges.
The point here is not that you fould not make one with a better design but that they chose not to. Just as diebold chose to use interpreted code on the ballot configuration cards that has the authority to re-write the vote files.
SO it's not that you cannot make a secure system--eventually--but that there isn't even the slightest effort to attend to some mac-truck size holes. they know they are their and they prefer to hide them in propriatary obfuscation not secure them. These are not people we can just trust because they seem nice. You have every right to be 100% skeptical because every time someone looks hard we find they are not fixed right.
I submitted it a few months ago. Gave them a tar file that runs the exploit. Wrote it myself. It works. It's not a programming bug that's creating a security hole but an flaw in the authentication policy design that grants persistent authentication across sessions. But I'm not saying any more.
If you are an admin user I can get root access without knowing your password. the mac security framework is not secure. I'm not going to tell you how as it's an unpublicized existing security hole that requires a large policy change and wont likely happen for some time. But it exists. You do NOT want to work as admin all the time. you want to selectively activate admin as needed and require it to ask you a different than normal password when you do.
Virtually all the tom foolery suggested inthe article is unneeded since on macs there is a better solution. Have two logins. One has admin privs and one does not. use the latter for your bussness.
While this can be terrifically painful on Linux and Windows its not painful at all on a mac. What happend is that nearly anytime you do an opertaion that requires root privledges from the gui the mac does it but first pops up an authentication box that wasks not for your everyday account password but instead your admin user password. So it's nearly seamless.
For the few cases where this wont suffice, you can either fadt user switch to admin, or you can pull up a terminal and su to the admin.
this has all the same protections the sill approach advocated in that article suggests.
Why is everyone reacting so negatively to this. It's the first step in what is fundmantelly a great idea to elimate spam. namely:
Step1: anything that is not whitelisted by the receiver, and otherwise does not bear a stamp is by definition SPAM.
step2: (Not implemented yet) a universal postage system not an AOL only postage system.
What makes this great is that it can be done very seemlessly and nails the problem. If someone is willing to send you something unsolicited and pay for it then it may turn out to be junk mail but it's not a spam flood since they do have to pay for it. Right now I get junk mail in my snailMail box every day. It's annoying but it's not a flood. Occasionally I do get something interesting (e.g a better deal on DSL, an event in town, a sale at the hardware store, a buck off starbucks). But it's NOT a FLOOD. just imagine if mailing Junk mail cost nothing and printing it cost nothing. Imagine the flood that might happen in snailMail.
So we need a stamp to damp the flood. It's not that we want to elminate unsolicited e-mail. We just need to make it cost the sender a small amount.
The awkward thing about AOL is they have not done step 2.
People are tarring this iniative as though it were AOL trying to profit off of preferred spammer. That could be the case, depending on how high the fee is and who pockets it (why not let the spam recipient pocket it---open this e-mail and you could win an ipod).
But it's win-win. We need the fee to damp spam. and to the extent that AOL makes more money then it's likely they will also lower their costs of access to consumers. Or maybe they won't. Consumers might even pay extra to live in the land on minimal spam.
Move on is painting this as sinister. It's not. Moreover, this policy might needs some tweaks. for example suppose that politcal e-mail got a free pass and commercial e-mail had to pay. I'm not spammed by political e-mail yet since it would backfire.
AOL may have implmented it slightly wrong but charging a postage stamp for e-mail is exactly what need to be done. We need some form of micro payment system for sending e-mail. One concept here is that the payment is only collected if the recipient marks the mail as spam, otherwise it's refunded.
The idea of charging for a resource you have already paid for in other ways or is otherwise free is an almost universally accepted concept in ecomonics as the best way, on a large scale, to avoid the trajedy of the commons. It's been noted since there were people to note it that livestock herders always overgraze public shared lands but generally they manage their own private land sustaibly. It's one of the primary arguments in favor of private property rights.
Taxes are not always about raising money. Recently it's been proposed that there be a tax on trades at stock exchanges. This would act as a damper on excessive day trading activity. (some day trading activity is good because it arbitrages the market inequity and increases liquidity, but too much increases volatility).
Sometimes this same effect can be done with a refundable deposit rather than a tax. For example, when a bank takes in a deposit of money, it in turn must give some percentage, say 10%, to the federal reserve bank to hold onto. It's not a tax since it will be given back if the investor withdraws his funds. But it has a dampening effect. The bank will now loan out 90% of the deposit to other people who will buy things and those sellers will put their money back in the bank. At the end of the day there is 10 times as much money in circulation. If the federal reserve had not taken it's witholding that cycle would multiply the amount of money in circulation indefinitely.
So taxes or deposits can be good public policy. If we could charge everyone just a small amount extra for e-mails, even if they have paid for thie ISP already it's a good thing. If we can make it refundable like a deposit system it's even better. It's no different from the fact that people who graze on public lands already paid for the lands once in their taxes, but if we charge them an extra fee per head of cattle they don't overgraze.
But there's technical problems to implementing this micro payment system which is why AOL is trying simpler systems first. But this would work even better if everyone did it not just AOL.
of course bacteria have their own virus like properties. For example, they serialize their objectes and multi-cast them to other bacteria for remote processing. Sometimes data values from that compuation. That is to say, bacteria have plasmids which a small usually circular chunks of data that are docked along side their primary dna. these plasmids are processed by the local host bacteria to get it's data and instructions. But it can also give these plasmids to other bacteria and accept them. That's how for example, antibiotic resistance is commonly propagated. The instructions for it get put on a plasmid and distibuted to other bacteria for use. thus like viruses this enable the net DNA of the host to change after birth.
In separate analogy. It's interesting to notice that like von neumann's architecture DNA intersperses data and instructions. And of course we also get buffer overflow error too where data becomes instructions. I've foundit intriguing that Von Neuman also felt this ambiguity was more powerful than separation of data and instructions. These days keeping the separate is of course a big problem in robust programming. Yet life, the ultimate robust system, does the same thing.
I beleive this is supposed to be more than multi-casting. I think Cringley was saying that Akami can't handle more than 150,000 simultanoues streams of the same stream let alone different streams. I bet they multi-cast those streams. As I read it he means that to multi-cast to 30 million folks you need to have a tree structure with each node multi-casting it's part. So now simply multi-casting is not the solution.
P2P narrowcasting so that everyone can watch their favorite show any time of day _they choose_ is like telling everyone in a crowded hot tub to move to the other side simultaneously.
p2p Broadcasting a single feed is like having everyone shift over one seat.
you get to sit next to the jet the same amount time. But you may not get to sit there when you choose.
Is there a way we can set up OS X so that certain commands (delete, for example) require a superuser? What you are asking for specifically would be impractical since you could not change any documetns. But look up access controll lists on tiger if you want to know about fine grained control of user priv.
no I tested this as an unprivledged user and the exploit runs. I notice that the exploit may fail if terminal.app is already running. It runs but then fails to open the calaculator.app as promised.
Nah the force issue is irrelvant. if the only thing that mattered here were the material strenght forces then you siply make the motor smaller to cahive the same torque. So that's not the point.
the key point it if there is any net gain at all. The static force analysis simply does not give the answer. As I said adding a spring would do exactly the same thing as adding a permenant magnet. But then it becomes obvious that there no net gain because the you had to pay the effort of loading the spring.
Since they rely on this static argument without giving a dynamic argument it seems like bullshit to me. My bullshit detector is further raised when they present the finite element calculation to back up the static arguments. It's a huge calaculation that backs the worng argument. this is just plane weird. it looks like a delberate attempt to inject bamboozle ment into it. Do they know what the hell they are talking about? Then where's the dynamic analysis?
As I understand it, the claim of above unity energy utilization in the articel summary is (of course) false and not being made for this motor.
What they are saying is above unity torque production. And here unity simply means the ratio with respect to a particular arbiratrily chosen standard. It's not a magic number. Just a way to avoid using units in the discussion.
Now what appears to be happeing is that if the rotor were stopped and one measured the torque on the rotor (or linear actuator) then you would find that this force was four times as high as a motor without the parallel path technology, running at the same current and the same number of windings.
Now we can see that this is sort of misleading. If we kept the current constant and the windings constant then the force or toruqe is higher in a non-moving rotor or actuator. But in a non-moving system one can, for the same current always increase the number of windings to increase the force. The ultimate limit comes from several practical realities. 1) increasing the windings increases both the impedance and residual reactance of the motor making it lossy and limiting it's frequency response. 2) The upper limit is reached when the magnetic flux is no longer contained by the ferrite. Both motors probably have a problem with #2 but the parallel path motor has fewer windings for the same level of force as a conventional motor.
Okay but that is still begging the question since were talking about non moving motor. adding in a permenant magent to boost the force is a lot like adding a spring to boos the force. You pay for it by the energy it took to load the spring.
Once this motor starts moving then one has to do a dynamic anayis to the flux collapsing as the rotor or actualtor moves is drawn into the field. What does this do the current in the motor? What does this do to it's complex impedance? I don't actually know the answers to those questions. The static analysis is simply bogus for concluding that. But if one were to maintain the "spring" analogy then it seems like one could not possibly be getting any net gain.
what this device does seem to be doing however is to make an assymetric pull on the acutator. that is it pulls on one arm of the motor with 4 times the torque and the other arm with no torque at all. That might possibly lead so some sort of alteration in the lead-lag curve of of the phase response of the motor at different speeds. If so it might somehow make a motor with a given amount of windings and ferrite optimally usitize it's material content better.
So if there is any gain at all here I suspect it lies with this latter effect. But I cant' do the analysis to be sure.
My point was that while we associate magnetism with low power persistent memory and electronics with fast, high power memory, you are going to have to shed the desirable properties of magnetism to achieve speed. At that point you may find it as leaky and power hungry as electronics. Conversely, if you are willing to make electronics slower you can make more ideal, less leaky transistors. I was not saying that transistors in use have ideal properties, but that extrapolating current magnetic goodness to it's future applications may make it less ideal too.
Wikipedia entry for Magnetic Bubble memory. I worked on Magnetic Bubble memory at IBM san jose, and the wired article sounds like this is the nano-scale version of this with some big improvements in how they are manipualted. Back then the "bubbles" were a few microns in size. You patterns permaloy onto the surface of a magnetic material. Usually this was a long loop of almost touching chevrons or T-shaped permaloy elements. the bulk materila was polarized one direction (normal to the chip) and inversions in this formed round "bubbles" for reasons simmilar to surface tension these bubbles were stable in one size and liked to stick to the chevron. Under a polarized light microscope you could see the "bubbles" in contrast sticking to the chevrons, giving them their name due to their appearance. one bubble stuck to one chevron. and the presence or absense of a bubble on a chevron was a 1 or 0. in some fancy schema the bubbles could hold internal higher order domain structures to encode more than one bit per bubble but these were never made practical.
A rotating magnetic field transverse to the chip would cause the chevrons to act like little iron bar bagnets pulling the bubble from one side to the other. because the chevron shape is asymetric it acted like a rachet and would only move the bubble unidirectionally. If the field was strong enough the bubble would then "leap" to the next chevron. Under the microscope you saw marching "bits" moving along. so you could move all the bit patterns like a train along the tracks in a bulk matterial with one layer of passive patterning. at one point in the loop track you placed a reader and a writer. this way you had sequential access to any bit and could inject or delete bits in the train.
When the power went off the bubbles stayed put.
It never made it to market (fuji made some) because it's niche was too small. it was slower than ram but faster than a hard drive. it was cheaper than ram but more expensive than a hard drive. At the time it was denser than ram but less dense than a harddrive. Thus it's only use was as a cache between ram and harddrives and in applications where robustness and non-voltility would be valuable like high-radiation sattelites and point of sale terminals. The latter market was eaten by EAROM and then flash memory.
this new material sounds like it uses simmilar concepts but is much smaller and actually performs bubble logic. Not sure about where the clock comes from: perhaps it's still a rotatin mag fiield?
Since magnetic monopoles dont exist, you have to use magnetic dipoles or higher order moments. this translates in to macoscopic structures. It's hard to see how this could beat monopole electrons in size or group velocity. As for power consumption, it's true that magnetism can have low queiscent power consumption because of it's hysterises making it non-volatile. But you pay aprice for this when you have to switch it's state. on the other hand the ideal transistor consumes no power when it is not switching states. If you got rid of the hysteresis in magnetism to make it faster and lower power then it too will become volatile like electronics.
I can see how this could create dense active bulk storage, such as was done long ago with magnetic bubble memory. But I'm skeptical about a pure magnetic logic system beating electronics.
Public utuilities are normally regulated. The reasons for that are well established. Companies in the utility markets are not generally are not cherry pick the most profitable customers. Instead for being allowed to operate they are also required to serve the public interest in other matters. That's why you have the public access channel on cable TV , the public alert systems on radio, why rural communities have electricity, and why the power company cant simply shut off the juice to the old/infirm without certain procedures. Some of those Odious fees on your phone bill pay for things like universal 911 connectivity.
We generally strived to avoid two tierer public power or phone service in their early days. Of course deregulation did take place in the phone arena eventually did make sense but only after ubiquitous access had been achieved and was affordable.
So we have to be careful about two tiered proposals for the internet. It might be okay but it should be scrutinized from a public policy perspective not a bussiness perspective.
Aye Yay yay ya yay
Deusch was a Cron-ay
he took orders from Che-nay
he made up his facts
science was not for him
and the job was the repay
Aye Yay yay ya yay
He was a presidential tody (tod-day)
creation was his mainstay
he made up his facts
truth at his whim
incuding his own resume
Congratutulations you are the first person to understand my post. Every other commentor has got hung up in knee jerk response to saying windows might be an important reason for IBM to port this to x86. The point of course was that there's lots of reasons this will happen and apple will be the beneficiary most poised to exploit it fast.
yes i realize this is not the same thing, but it stands to reason this will be IBM's conduit for this new technology to the 0x86 world. and thus to Apple.
One of the reasons AMD caught up with intel was IIRC they liscenced IBMs Silicon-on-insulator technology to get lower heat dissipation. If IBM once again liscences this to AMD then you will have this technology running on 0x86 instruction sets. Or conversely, if it's a world beating technology IBM may be able to persuade Intel to liscence it's 0x86 instruction sets.
No matter how fast the chip is, unless it runs 0x86 it's never going to show up in home or bussiness computers. Windows is the glue that holds that enterpise together and unless windows runs on it, people wont buy it and dell wont sell it unless there's a market.
So Apples will probably by able to access this in the new 0X86 mode. but it's not going to be just a simple processor replacement since you also will need RAM and busses that can handle the suction this processors is going to have. So motherboards are going to have to be entirely redeisnged to cope.
So this is going to be good news for apple since they are an agile hardware manufacturer that is not locked into the PC motherboard paradigm and are free to create their own firmware and software to run on radical hardware variants.
This sun charger will benefit people with short commutes much more than 10%. maybe as much as 100%. Whereas it will hardly benefit at all anyone with a long commute. Yet it's precisely the latter folks that benefit the most from pruis ownership. Moreover city drivers probably don't park their prius on the street, but rather in a sunless parking garage. So this will not affect urban pollution.
One the upside this probably works best during summer when gas prices are peaked.