Actually, brining a bunch of money and starting businesses is one of the easiest ways of getting to stay in the US. They really like people who do that, with good reason.
Afaict "bunch of money" in this context means a million dollars.
Read "value" as "something that will make money for oracle" and it makes sense.
AIUI the java model was to give it away free on the desktop/server and then once they had an army of java programmers out there make money out of it in other product lines like mobile and embedded.
Mobile phones have moved from a variety of javame supporting system (which paid licensing fees to oracle) to andriod (which doesn't). Oracle is unhappy about this.
If they could somehow rig a suite of weight sensors for the wheel trucks, they 'd get something
If we assume the wheel trucks can be modelled as point supports (reasonable given the plane is much larger than the wheel trucks) then the forces through them would tell you the weight of the plane and the 2D location of the center of gravity. They would not tell you the height of the center of gravity.
If the fuel load and fuel tank arrangements are known it should be possible to predict how that center of gravity will move as fuel is drained.
I would expect that with most planes front-back balance is a bigger issue than top-bottom balance (because planes tend to be small top-bottom) or side-side balance (since the only thing carried in the wings is usually fuel which is easy to balance) so measuring gear forces would seem like a reasonable method of balancing to me.
Disclaimer: IANAP, this is theoretical musing, not practical advice.
cellphone networks were designed to handle voice from the start, packet data* was added as an afterthought and is basically the bottom of the priority pile. At least on O2 in the UK it's common to find areas where voice works fine but packet data is unusable. Poor voice quality on cellular networks is a result of two things, firstly the unreliability of the wireless channel and secondly limited available bitrate leading to the use of low bitrate codecs. Even in the more modern technologies which are moving away from circuit switching voice calls still have priority.
* GSM at least also allows for for circuit-switched data calls and has done for a long time but high cost and low data rate meant it wasn't used much.
-X
Enables X11 forwarding. This can also be specified on a per-host basis in a configuration file.
X11 forwarding should be enabled with caution. Users with the ability to bypass file permissions on the remote host (for the user's X authorization database) can access the local X11 display through the forwarded connection. An attacker may then be able to perform activities such as keystroke monitoring.
For this reason, X11 forwarding is subjected to X11 SECURITY extension restrictions by default. Please refer to the ssh -Y option and the ForwardX11Trusted directive in ssh_config(5) for more information. -x
Disables X11 forwarding. -Y
Enables trusted X11 forwarding. Trusted X11 forwardings are not subjected to the X11 SECURITY extension controls.
ForwardX11Trusted
If this option is set to “yes”, remote X11 clients will have full access to the original X11 display.
If this option is set to “no”, remote X11 clients will be considered untrusted and prevented from stealing or tampering with data belonging to trusted X11 clients. Furthermore, the xauth(1) token used for the session will be set to expire after 20 minutes. Remote clients will be refused access after this time.
In summery it seems that -X is more secure than -Y but can break things in some cases.
The problem is "big enough key", how big is big enough? best estimate seems to be that 4096 bit is fine for the forseeable future but noone really knows because noone can predict how integer factorisation algorithms will progress.
When RSA was developed it was thought that 1024 bit keys would be secure essentially forever. Unfortunately the combination of advancements in integer factorisation techniques and advancements in computing power have brought factoring a 1024 bit key into the range of computationally feasible (though very expensive). Furthermore that is based on what is publically known, it's not beyond the realms of possibility that the spooks know techiquest that the public doesn't.
Unfortunately 1024 bit keys were the standard size for years and so are extremely common. Getting rid of them is going to involve quite a bit of pain. It's telling that openssh only plan to refuse keys smaller than 1024 bit, not keys that are exactly 1024 bit.
With academic papers the author list is usually a flat list. Sometimes the first authors are the key ones but many papers simply have the authors in alphabetical order. Combine that with a writing style that ephasisies what was done over who did it and it's pretty difficult to figure out who the main drivers of the project were and who were just workers.
Contrast that to movie or videogame credits where there is a structure that tell you who played (or in the case of videogames voiced), who the people driving the project were, which category each of the workers fell into and so-on.
Seriously, they want to drop the threshold to AUD$20? I thought it was uneconomic to collect the tax below purchases of AUD$100?
mmm, thats the situation we have in the UK (and I belive the EU in general) and it sucks. Order a £16 (inc delivery) item from outside the EU, pay £3.20 VAT and pay ~£10 handling charge for collecting the VAT.
Store everything in a system in UTC0. All internal times a dealt with in this way. The only time you ever have to worry about timezone or DST is when displaying them to users. This simplifies everything enormously.
It simplifies some things but breaks others.
If a user schedules a weekly event they will almost certainly want it to be at the same time each week in local time, not the same time each week in universal time. If the user schedules an event in the future they probably want it to remain at the same local time even after their government changes the mapping rules.
Given a defined time period, average power and total energy are for the most part two different ways of measuring the same quantity.
"IT equipment energy" is the energy delivered to the IT equipment (It equipment doesn't "provide" energy). PUE is a measure of the energy efficiency of the facility, NOT of the efficiency of the IT equipment hosted within that facility. A PUE of 1 means that all the energy going into the datacenter is delivered to the IT equipment. A PUE of 2 means half the energy delivered goes to IT equipment and half goes to other things (coolng, power distribution losses, UPS losses)..
You can calculate PUE over any time period but for an overall figure you would normally want to calculate it over a year (or a whole number of years) as there will likely be substantial seasonal variations.
If you host the same IT equipment in a low PUE datacenter and a high PUE datacenter then the equipment in the high PUE datacenter will result in greater power consumption from the grid than in the low PUE datacenter. HAving said that of course inefficient IT equipment hosted in a low PUE datacenter can still be worse overall than efficient IT equipement hosted in a high PUE datacenter.
You can format them to use any other file system you'd like.
Sure you can but AIUI to sell them in that state is a violation of the SD card spec.
Personally, I don't know why FAT is even used on SD cards in the first place. Lots of other file systems out there.
Because support for those other filesystems is not ubiquitous across many platforms including windows, mac, linux, whatever embedded environments camera vendors use etc. Support for FAT is.
That's not a problem if you are using it in an embedded system as a substitute for a hard disk, much more of a problem if you are using it for it's intended purpose of getting files from your camera to your PC.
For example some that are specific to flash,
BTW the filesystems you mention are designed for use on raw flash. If you are using a device with a flash translation layer (like a SD card or USB stick or EMMC) they aren't the filesystems to use. Thats what F2FS is for.
To me the interesting thing would be some sort of model one can use to estimate the danger of making a particular trip by different modes of transport. Comparing local car journeys to intercontinental air travel doesn't really help anyone.
It's not a simple problem, for example with car travel different models of car and different roads have different risk levels, with air travel different airplanes and different airports have different risk levels, with rail travel different tracks and trains have different risk levels. There is probablly a difficult balance between making the statistical buckets big enough to have meaningful data and making them uniform enough to give precision.
You know taxi cabs are also public transportation, right?
That's really a question of defintions. They are "public" in the sense they are not owned by the passengers and available for use by the general public but they are "private" in the sense that they carry one passenger or a private group of passengers at a time and that passenger/group tells them where to go.
And here comes the elephant in the room for this article: all that it says can also be applied to taxi cabs, which already exist and still the expected results aren't happening.
Where I live taxis cost £2 for the first half mile and about £2,50 per mile after that. According to the AA the marginal cost of running a basic car is about 20p per mile and the fixed costs are about £2K per year. Unless your total miles travelled is very low or you live/work somewhere were parking is extremely expensive using taxis is substantially more expensive than keeping a car. As for public transport where I live for just over £1K per year I can (and do) buy a pass that lets me travel by bus and train anywhere in the conurbation.
I could be wrong but aiui taxis being an expensive option is the typical scenario.
Therefore afaict normal people only use taxis on an occasional basis as a fill-in solution. If automated cars can bring taxi prices down to say 60p per mile such that they are competitive with private cars at the 5K miles per year level I would expect them to be much more popular.
how do natural gas generators beat that, and can whatever tricks those are be applied back to coal/gas/nuclear?
When it comes to heat engines you have something called the carnot efficency which is an upper bound on the possible efficency. The carnot efficiency is 1-(thot/tcold) where thot and tcold are absoloute temperatures. While real efficiencies are obviously lower than carnot it is still generally true that widening the gap between thot and tcold improves efficiency.
For a given type of heat engine the hot end is limited by material considerations wihle the cold end is limited by size considerations and/or ambient temperatures. However different types of heat engine work in different temperature ranges. By combining gas turbines which work at very high temperatures with steam turbines which operate at lower temperatures the temperature range can be widened and the efficiency improved.
However gas turbines are internal combustion which limits the fuel types. IIRC someone did try running one off powdered coal but the ash destroyed the turbine blades. I guess you could in theory build and external combustion gas turbine but you would need a very high termpature working fluid to carry heat to the turbine which I suspect would create practical engineering problems and drag down your overall efficiency. People have also run them off coal gassification systems but losses in gassification drag down the overall efficiency. So that leaves oil and gas.
Oil isn't used much* for electricity generation due to being substantially more expensive** than coal or gas. I expect the oil efficiency figures are dragged down by use in peak load plants, supplies for isolated communities and similar situations which are too small and/or too rarely used to justify CCGT.
Efficiency becomes a problem when you start wide ranging your inputs or your outputs. I.e. you need 5-48V DC inputs (120V - 230V isn't too hard), or you need a wide ranging current output.05-5A all while staying within a tight tolerance. Then efficiency becomes a problem as you hit some trade-offs.
And that is the thing with a phone "charger"*. I can well imagine it's efficiency while actually deliverying 1A is pretty good but what is it's overall efficiency in typical use.
* Really a power supply, the actual charging circuit is in the phone and has losses of it's own on top of those in the power brick.
Isn't that what the motor run capacitor is supposed to help with?
No, the capacitors in a single phase AC motor are to make the magnetic field rotate rather than merely oscilate. Some motors switch the cap out once started, others leave it in.
I've never needed more than a 50A breaker, and I'm using reasonably quick-acting breakers.
Can you be more specific about what breakers you are using? I know here in the UK we have two common types, "type B" breakers trip quickly at 3-5 times overcurrent while "type C" breakers trip quickly at 5-10 times overcurrent. Smaller overcurrents are handled by the thermal part of the breaker which trips much slower.
Correct, after a certain distance (too lazy to look it up) the AC power lines become an antenna. So there is a maximum length for AC power lines.
Well every power line is an antenna to some extent. Obviously the affect gets bigger with distance but there isn't some magical distance beyond which AC power transmission becomes unfeasable. It's more of a gradual thing with the question being balancing the lower line losses of DC
The real advantage of DC include 1: the lack of losses to electromagnetic radiation 2: a massive reduction in the impact of line capacitance and inductance( if rate of power transfer was constant they would have no impact but if it's not constant they will still have some impact). While capacitance and inductance don't dissipate net power in themselves they can cause extra current flow and/or extra voltage drop which increase losses elsewhere. 3: the lack of skin affect which pushes currents to the surface in large AC cables 4: the lack of need to syncronise systems before interconnecting them. 5: insulation strength requirements depend on peak voltage, achivable power transmission depends on rms voltage and current. For DC peak=rms for AC peak=sqrt(2)*rms
But with AC lines you can use 3 phase wiring, cutting the required quantity of metal in half compared to DC.
bullshit.
(3 phases balance, and therefore do not need a return wired)
The same is true of a centre tapped DC or single phase AC system.
True, the question is what is the relative danger.
One problem is that people conflate the questions of voltage/current with the question of ac/dc. As a general rule for a given load a lower voltage system will have a lower electric shock risk but will have a higher fire risk.
DC is far more prone to sustaining arcs than AC. DC is also far more prone to causing unplanned electrochemical activity.
Dunno if you are being serious or not, assuming you are for the sake of discussion.
Nokia isn't coming back
I wouldn't be so sure about that.
MS did not buy Nokia (despite headlines from people who thought the most publicaly visible part of a company was the only part), they bought Nokia's handset division, the lumia brand, some time limited rights to use the Nokia brand, and some time-limited no-compete clauses preventing Nokia from using their own brand on handsets for a while. In the not too distant future Nokia will be free to start a new handset division or license their brand to someone else.
Microsoft can rest easy now, the threat to Windows Phone has been eliminated.
Somewhat true, having first party handsets means they can keep offering phones even if the rest of the industry thinks their OS is a bad idea and some goodwill will have transferred from nokia to MS through the lumia brand and their distribution agreements but it's a very expensive way to maintain a distant third in the smartphone OS marketplace.
I don't know what would happen if everybody insisted on withdrawing their money in cash, but then I don't know what would happen if I were struck by lightning before and after winning the Powerball lottery, and that's more likely.
It's unlikely because people trust the banking system and people trust the banking system because the government steps in to prevent most bank failures and covers small depositers in the rare cases they do let a bank fail. The government is gauranteed to be able to sort out bank failures because they have the ability to create money by fiat*.
As you say in the old days of the gold system bank runs were common and bitcoins are far more volatile than gold. I maintain that anyone who gets involved in fractional reserve bitcoin banking is an idiot.
* Whether they physically print that money or just maniplulate some numbers in a cental bank database is largely irrelevent.
External PCI based interface in a server rack: fine External PCI based interface on a laptop as an extra interface: probablly fine in most cases though potential hazard in some environments (e.g. hot desking with hardware that uses the PCI based interface) External PCI based interface on a laptop as a replacement for standard display and network ports: dangerous
When you deposit $US with a US bank, in a savings account or CD, it can loan out 100% of your deposit. If banks offered BTC-denominated savings accounts, they'd work the same way. If you're thinking "but wait, that means there wouldn't be enough bitcoins in existence to allow everyone to withdraw their deposits", then congratulations, you understand how banking works.
The difference of course is with fiat currency the government/central bank can "print"* money on demand and lend it to the commercial banks so they can cover their customers withdrawals.
With BTC denominated accounts if everyone tries to withdraw their BTC at once the bank has a big problem. They can try to buy BTC to cover the withdrawals but there is no guarantee they will actually be able to.
* It starts out as entries in the central banks database but if the customers are demanding their money in cash then that cash will have to be physically printed and sent to the banks.
bitcoins reside in "unspent outputs" in the blockchain. The unspent outputs are associated with an "address". An "address" is a cryptographic hash of a public key and the holder of the corresponding private key can spend the bitcoins.
A wallet is basically a collection of private keys for addresses (or sometimes just a generator seed for said keys). To an outside observer it is not visible whether two addresses are part of the same wallet or not. The only thing that distinguishes between a customer withdrawl and a move to cold storage is the internal records of the exchange. If the echange isn't keeping proper records it is unlikely to be feasible to distinguish thefts from legimitate withdrawls (and even if the exchange is keeping records do you trust those records to be honest?)
And yes if the private key for an address is lost (or someone sends bitcoins to an address that wasn't obtained by hashing a public key) the coins are gone for good. Bitcoin propoonents maintain this is not a significant issue.because of the divisibility of bitcoins, I have some reservations about that.
Slashdot Mirror
Actually, brining a bunch of money and starting businesses is one of the easiest ways of getting to stay in the US. They really like people who do that, with good reason.
Afaict "bunch of money" in this context means a million dollars.
Read "value" as "something that will make money for oracle" and it makes sense.
AIUI the java model was to give it away free on the desktop/server and then once they had an army of java programmers out there make money out of it in other product lines like mobile and embedded.
Mobile phones have moved from a variety of javame supporting system (which paid licensing fees to oracle) to andriod (which doesn't). Oracle is unhappy about this.
For my cheap computing needs, I'd rather get the Raspberry Pi, which is Cortex A9
Umm no, the raspberry pi 2 is Cortex A7. Original raspberry pi was some arm11 variant.
If they could somehow rig a suite of weight sensors for the wheel trucks, they 'd get something
If we assume the wheel trucks can be modelled as point supports (reasonable given the plane is much larger than the wheel trucks) then the forces through them would tell you the weight of the plane and the 2D location of the center of gravity. They would not tell you the height of the center of gravity.
If the fuel load and fuel tank arrangements are known it should be possible to predict how that center of gravity will move as fuel is drained.
I would expect that with most planes front-back balance is a bigger issue than top-bottom balance (because planes tend to be small top-bottom) or side-side balance (since the only thing carried in the wings is usually fuel which is easy to balance) so measuring gear forces would seem like a reasonable method of balancing to me.
Disclaimer: IANAP, this is theoretical musing, not practical advice.
BS,
cellphone networks were designed to handle voice from the start, packet data* was added as an afterthought and is basically the bottom of the priority pile. At least on O2 in the UK it's common to find areas where voice works fine but packet data is unusable. Poor voice quality on cellular networks is a result of two things, firstly the unreliability of the wireless channel and secondly limited available bitrate leading to the use of low bitrate codecs. Even in the more modern technologies which are moving away from circuit switching voice calls still have priority.
* GSM at least also allows for for circuit-switched data calls and has done for a long time but high cost and low data rate meant it wasn't used much.
http://www.openbsd.org/cgi-bin...
-X
Enables X11 forwarding. This can also be specified on a per-host basis in a configuration file.
X11 forwarding should be enabled with caution. Users with the ability to bypass file permissions on the remote host (for the user's X authorization database) can access the local X11 display through the forwarded connection. An attacker may then be able to perform activities such as keystroke monitoring.
For this reason, X11 forwarding is subjected to X11 SECURITY extension restrictions by default. Please refer to the ssh -Y option and the ForwardX11Trusted directive in ssh_config(5) for more information.
-x
Disables X11 forwarding.
-Y
Enables trusted X11 forwarding. Trusted X11 forwardings are not subjected to the X11 SECURITY extension controls.
http://www.openbsd.org/cgi-bin...
ForwardX11Trusted
If this option is set to “yes”, remote X11 clients will have full access to the original X11 display.
If this option is set to “no”, remote X11 clients will be considered untrusted and prevented from stealing or tampering with data belonging to trusted X11 clients. Furthermore, the xauth(1) token used for the session will be set to expire after 20 minutes. Remote clients will be refused access after this time.
In summery it seems that -X is more secure than -Y but can break things in some cases.
The problem is "big enough key", how big is big enough? best estimate seems to be that 4096 bit is fine for the forseeable future but noone really knows because noone can predict how integer factorisation algorithms will progress.
When RSA was developed it was thought that 1024 bit keys would be secure essentially forever. Unfortunately the combination of advancements in integer factorisation techniques and advancements in computing power have brought factoring a 1024 bit key into the range of computationally feasible (though very expensive). Furthermore that is based on what is publically known, it's not beyond the realms of possibility that the spooks know techiquest that the public doesn't.
Unfortunately 1024 bit keys were the standard size for years and so are extremely common. Getting rid of them is going to involve quite a bit of pain. It's telling that openssh only plan to refuse keys smaller than 1024 bit, not keys that are exactly 1024 bit.
With academic papers the author list is usually a flat list. Sometimes the first authors are the key ones but many papers simply have the authors in alphabetical order. Combine that with a writing style that ephasisies what was done over who did it and it's pretty difficult to figure out who the main drivers of the project were and who were just workers.
Contrast that to movie or videogame credits where there is a structure that tell you who played (or in the case of videogames voiced), who the people driving the project were, which category each of the workers fell into and so-on.
Seriously, they want to drop the threshold to AUD$20? I thought it was uneconomic to collect the tax below purchases of AUD$100?
mmm, thats the situation we have in the UK (and I belive the EU in general) and it sucks. Order a £16 (inc delivery) item from outside the EU, pay £3.20 VAT and pay ~£10 handling charge for collecting the VAT.
Store everything in a system in UTC0. All internal times a dealt with in this way. The only time you ever have to worry about timezone or DST is when displaying them to users. This simplifies everything enormously.
It simplifies some things but breaks others.
If a user schedules a weekly event they will almost certainly want it to be at the same time each week in local time, not the same time each week in universal time. If the user schedules an event in the future they probably want it to remain at the same local time even after their government changes the mapping rules.
Given a defined time period, average power and total energy are for the most part two different ways of measuring the same quantity.
"IT equipment energy" is the energy delivered to the IT equipment (It equipment doesn't "provide" energy). PUE is a measure of the energy efficiency of the facility, NOT of the efficiency of the IT equipment hosted within that facility. A PUE of 1 means that all the energy going into the datacenter is delivered to the IT equipment. A PUE of 2 means half the energy delivered goes to IT equipment and half goes to other things (coolng, power distribution losses, UPS losses)..
You can calculate PUE over any time period but for an overall figure you would normally want to calculate it over a year (or a whole number of years) as there will likely be substantial seasonal variations.
If you host the same IT equipment in a low PUE datacenter and a high PUE datacenter then the equipment in the high PUE datacenter will result in greater power consumption from the grid than in the low PUE datacenter. HAving said that of course inefficient IT equipment hosted in a low PUE datacenter can still be worse overall than efficient IT equipement hosted in a high PUE datacenter.
You can format them to use any other file system you'd like.
Sure you can but AIUI to sell them in that state is a violation of the SD card spec.
Personally, I don't know why FAT is even used on SD cards in the first place. Lots of other file systems out there.
Because support for those other filesystems is not ubiquitous across many platforms including windows, mac, linux, whatever embedded environments camera vendors use etc. Support for FAT is.
That's not a problem if you are using it in an embedded system as a substitute for a hard disk, much more of a problem if you are using it for it's intended purpose of getting files from your camera to your PC.
For example some that are specific to flash,
BTW the filesystems you mention are designed for use on raw flash. If you are using a device with a flash translation layer (like a SD card or USB stick or EMMC) they aren't the filesystems to use. Thats what F2FS is for.
To me the interesting thing would be some sort of model one can use to estimate the danger of making a particular trip by different modes of transport. Comparing local car journeys to intercontinental air travel doesn't really help anyone.
It's not a simple problem, for example with car travel different models of car and different roads have different risk levels, with air travel different airplanes and different airports have different risk levels, with rail travel different tracks and trains have different risk levels. There is probablly a difficult balance between making the statistical buckets big enough to have meaningful data and making them uniform enough to give precision.
You know taxi cabs are also public transportation, right?
That's really a question of defintions. They are "public" in the sense they are not owned by the passengers and available for use by the general public but they are "private" in the sense that they carry one passenger or a private group of passengers at a time and that passenger/group tells them where to go.
And here comes the elephant in the room for this article: all that it says can also be applied to taxi cabs, which already exist and still the expected results aren't happening.
Where I live taxis cost £2 for the first half mile and about £2,50 per mile after that. According to the AA the marginal cost of running a basic car is about 20p per mile and the fixed costs are about £2K per year. Unless your total miles travelled is very low or you live/work somewhere were parking is extremely expensive using taxis is substantially more expensive than keeping a car. As for public transport where I live for just over £1K per year I can (and do) buy a pass that lets me travel by bus and train anywhere in the conurbation.
I could be wrong but aiui taxis being an expensive option is the typical scenario.
Therefore afaict normal people only use taxis on an occasional basis as a fill-in solution. If automated cars can bring taxi prices down to say 60p per mile such that they are competitive with private cars at the 5K miles per year level I would expect them to be much more popular.
how do natural gas generators beat that, and can whatever tricks those are be applied back to coal/gas/nuclear?
When it comes to heat engines you have something called the carnot efficency which is an upper bound on the possible efficency. The carnot efficiency is 1-(thot/tcold) where thot and tcold are absoloute temperatures. While real efficiencies are obviously lower than carnot it is still generally true that widening the gap between thot and tcold improves efficiency.
For a given type of heat engine the hot end is limited by material considerations wihle the cold end is limited by size considerations and/or ambient temperatures. However different types of heat engine work in different temperature ranges. By combining gas turbines which work at very high temperatures with steam turbines which operate at lower temperatures the temperature range can be widened and the efficiency improved.
However gas turbines are internal combustion which limits the fuel types. IIRC someone did try running one off powdered coal but the ash destroyed the turbine blades. I guess you could in theory build and external combustion gas turbine but you would need a very high termpature working fluid to carry heat to the turbine which I suspect would create practical engineering problems and drag down your overall efficiency. People have also run them off coal gassification systems but losses in gassification drag down the overall efficiency. So that leaves oil and gas.
Oil isn't used much* for electricity generation due to being substantially more expensive** than coal or gas. I expect the oil efficiency figures are dragged down by use in peak load plants, supplies for isolated communities and similar situations which are too small and/or too rarely used to justify CCGT.
* https://flowcharts.llnl.gov/co...
**http://www.eia.gov/tools/faqs/faq.cfm?id=107&t=3
Efficiency becomes a problem when you start wide ranging your inputs or your outputs. I.e. you need 5-48V DC inputs (120V - 230V isn't too hard), or you need a wide ranging current output .05-5A all while staying within a tight tolerance. Then efficiency becomes a problem as you hit some trade-offs.
And that is the thing with a phone "charger"*. I can well imagine it's efficiency while actually deliverying 1A is pretty good but what is it's overall efficiency in typical use.
* Really a power supply, the actual charging circuit is in the phone and has losses of it's own on top of those in the power brick.
Isn't that what the motor run capacitor is supposed to help with?
No, the capacitors in a single phase AC motor are to make the magnetic field rotate rather than merely oscilate. Some motors switch the cap out once started, others leave it in.
I've never needed more than a 50A breaker, and I'm using reasonably quick-acting breakers.
Can you be more specific about what breakers you are using? I know here in the UK we have two common types, "type B" breakers trip quickly at 3-5 times overcurrent while "type C" breakers trip quickly at 5-10 times overcurrent. Smaller overcurrents are handled by the thermal part of the breaker which trips much slower.
Correct, after a certain distance (too lazy to look it up) the AC power lines become an antenna. So there is a maximum length for AC power lines.
Well every power line is an antenna to some extent. Obviously the affect gets bigger with distance but there isn't some magical distance beyond which AC power transmission becomes unfeasable. It's more of a gradual thing with the question being balancing the lower line losses of DC
The real advantage of DC include
1: the lack of losses to electromagnetic radiation
2: a massive reduction in the impact of line capacitance and inductance( if rate of power transfer was constant they would have no impact but if it's not constant they will still have some impact). While capacitance and inductance don't dissipate net power in themselves they can cause extra current flow and/or extra voltage drop which increase losses elsewhere.
3: the lack of skin affect which pushes currents to the surface in large AC cables
4: the lack of need to syncronise systems before interconnecting them.
5: insulation strength requirements depend on peak voltage, achivable power transmission depends on rms voltage and current. For DC peak=rms for AC peak=sqrt(2)*rms
But with AC lines you can use 3 phase wiring, cutting the required quantity of metal in half compared to DC.
bullshit.
(3 phases balance, and therefore do not need a return wired)
The same is true of a centre tapped DC or single phase AC system.
AC and DC are both dangerous.
True, the question is what is the relative danger.
One problem is that people conflate the questions of voltage/current with the question of ac/dc. As a general rule for a given load a lower voltage system will have a lower electric shock risk but will have a higher fire risk.
DC is far more prone to sustaining arcs than AC. DC is also far more prone to causing unplanned electrochemical activity.
Dunno if you are being serious or not, assuming you are for the sake of discussion.
Nokia isn't coming back
I wouldn't be so sure about that.
MS did not buy Nokia (despite headlines from people who thought the most publicaly visible part of a company was the only part), they bought Nokia's handset division, the lumia brand, some time limited rights to use the Nokia brand, and some time-limited no-compete clauses preventing Nokia from using their own brand on handsets for a while. In the not too distant future Nokia will be free to start a new handset division or license their brand to someone else.
Microsoft can rest easy now, the threat to Windows Phone has been eliminated.
Somewhat true, having first party handsets means they can keep offering phones even if the rest of the industry thinks their OS is a bad idea and some goodwill will have transferred from nokia to MS through the lumia brand and their distribution agreements but it's a very expensive way to maintain a distant third in the smartphone OS marketplace.
He said they would refuse him fiber to the premisis not fiber to the cabinet.
BT won't sell you FTTPoD (fiber to the premisis on demand) if you live in a flat. Probablly because of the internal wiring complications you mention.
I don't know what would happen if everybody insisted on withdrawing their money in cash, but then I don't know what would happen if I were struck by lightning before and after winning the Powerball lottery, and that's more likely.
It's unlikely because people trust the banking system and people trust the banking system because the government steps in to prevent most bank failures and covers small depositers in the rare cases they do let a bank fail. The government is gauranteed to be able to sort out bank failures because they have the ability to create money by fiat*.
As you say in the old days of the gold system bank runs were common and bitcoins are far more volatile than gold. I maintain that anyone who gets involved in fractional reserve bitcoin banking is an idiot.
* Whether they physically print that money or just maniplulate some numbers in a cental bank database is largely irrelevent.
Really I think it depends on the situation.
External PCI based interface in a server rack: fine
External PCI based interface on a laptop as an extra interface: probablly fine in most cases though potential hazard in some environments (e.g. hot desking with hardware that uses the PCI based interface)
External PCI based interface on a laptop as a replacement for standard display and network ports: dangerous
When you deposit $US with a US bank, in a savings account or CD, it can loan out 100% of your deposit. If banks offered BTC-denominated savings accounts, they'd work the same way. If you're thinking "but wait, that means there wouldn't be enough bitcoins in existence to allow everyone to withdraw their deposits", then congratulations, you understand how banking works.
The difference of course is with fiat currency the government/central bank can "print"* money on demand and lend it to the commercial banks so they can cover their customers withdrawals.
With BTC denominated accounts if everyone tries to withdraw their BTC at once the bank has a big problem. They can try to buy BTC to cover the withdrawals but there is no guarantee they will actually be able to.
* It starts out as entries in the central banks database but if the customers are demanding their money in cash then that cash will have to be physically printed and sent to the banks.
bitcoins reside in "unspent outputs" in the blockchain. The unspent outputs are associated with an "address". An "address" is a cryptographic hash of a public key and the holder of the corresponding private key can spend the bitcoins.
A wallet is basically a collection of private keys for addresses (or sometimes just a generator seed for said keys). To an outside observer it is not visible whether two addresses are part of the same wallet or not. The only thing that distinguishes between a customer withdrawl and a move to cold storage is the internal records of the exchange. If the echange isn't keeping proper records it is unlikely to be feasible to distinguish thefts from legimitate withdrawls (and even if the exchange is keeping records do you trust those records to be honest?)
And yes if the private key for an address is lost (or someone sends bitcoins to an address that wasn't obtained by hashing a public key) the coins are gone for good. Bitcoin propoonents maintain this is not a significant issue.because of the divisibility of bitcoins, I have some reservations about that.