Reading again, you meant changing one of the 4 sites to PV. Sorry. That approach wouldn't impact the efficiency of one of the solar thermal towers. But it would still pose the engineering cost problems.
I do wonder what the limitation is that makes it better to build 4 solar thermal plants rather than one big one. Maybe it can't handle that much heat? Maybe maintenance so they can shut one down and the others still function? Maybe aiming the mirrors over a larger distance is hard? Hmm...
Are you suggesting that they should remove some reflector mirrors and replace them with PV panels? Mixing technologies within a single site is poor economics in general, but with solar thermal it is particularly bad.
In general, mixing different technologies doubles the cost, makes maintenance harder, and removes the economy of scale. For example, they would need two different types of power infrastructure on one site. But in particular with solar thermal: more mirrors means more heat is focused onto the target, increasing power *and* temperature. Higher temperature = more efficiency. This same thing would happen with nuclear or coal or gas. Build one big coal plant, or one big gas plant. Building a 1/2 size gas plant and a 1/2 size coal plant on the same area would produce less power for a greater cost.
Nothing stops them from building a PV plant if that mix of fuel sources is better for them, but not at the same site.
Making a password longer or including symbols was much more effective.
Yet so many systems limit password lengths and forbid special characters. Example: My bank is one of the top 20 largest banks in the US, and they do not allow special characters in their web banking.
1) Some systems limit which special characters you can use! 2) I bet people don't like to use parenthesis, brackets, or braces because seeing mismatched pairs seems "wrong." Or maybe it's just programmers.
The Wikipedia article provides no indication of a conspiracy theory. It has a section on it it that cites only one reporter, who later apologized for having suggested it. A Google search for "Ahmed Mohamed clock conspiracy theory" turns up articles pointing to extreme right-wing pundits with vague theories about a 9/11 conspiracy, but no actual concrete claims of any wrongdoing.
Just because you are paranoid doesn't mean they aren't out to get you. But in this case, the author kinda is paranoid. He could use a course on web browsers and email.
The next morning, in my inbox, several spam e-mails urged me to invest in art. That was an easy one to figure out: I’d typed the name of the gallery into Google Maps.
It sounds like the author is alleging that Google gave his email address and marketing information to spammers. Is that true? Considering I have a gmail account that receives no spam at all, I think a more believable explanation is that he dropped his business card into a box somewhere, or signed-up on a list. In reality, 100% of my spam comes to the email address I have registered to my domain. My personal email gets nothing because I don't give it out.
Some people receive almost no spam. Other people get a 200:1 ratio of spam to real emails. Having done tech support, I can tell you by talking to someone for 5 minutes how much spam they get. Do they click on ads? Do they sign-up for stuff and give out their email? Do they play the lottery? Then they are in the high spam category. I bet a reporter is one of those people who gives out his contact information to absolutely everyone.
Another simple one to trace was the stream of invitations to drug and alcohol rehab centers that I’d been getting ever since I’d consulted an online calendar of Los Angeles–area Alcoholics Anonymous meetings. Since membership in AA is supposed to be confidential, these emails irked me.
Unless he created a dedicated email address specifically for the AA membership, he has no evidence of this. Again, more likely, he enaged in networking.
I don't even want to consider his example where his bluetooth somethingorother was transcribing his words and turning that into spam. That one is technically possible, but we just aren't there... yet.
With those complaints registered, many of the anecdotes in the story do make sense. A Google search triggered targeted ads on YouTube. Well yeah, Google owns both sites. This is one of the reasons people feared Google Plus: it was just *too* well integrated. I am just surprised that this is news to people at all. What do you think is in that 35 page license you clicked "accept" to in order to play that free Facebook game? Why do you think that flashlight app needs access to your contact list and the internet?
That anecdote is super compelling, but after reading it I don't understand.
1) Who is the other Nobel Peace Prize winner you are referring to? The article mentions Joanne Liu, but she isn't a nobel winner. So who is it? 2) Obama didn't order that strike anyway. But I'll let that slide since he is commander-in-chief.
I have no interest in major league sports, but the idea of writing an algorithm that tracks top fantasy football players' decisions and tries to create a team based on that meta-information sounds really cool to me. It would be really neat to see how successful it could be while knowing nothing at all about the game itself.
And the problem with that is...what? Are you saying you want troopers to be inefficient? If the troopers knew that an area tended to have more murders, would you not want them to increase patrol efforts in that area?
Experience shows me that this problem is not limited to companies using JIRA. And some of the competing products aren't that great either. In my personal survey of local developers, the companies that love Agile the most aren't actually following the process: but they don't know or care. The ones that drank the kool-aid and try to stick to it function they way you described. The first group says things like "We do resources planning in Microsoft Project or on a big sheet of paper" and "We don't bother with points." A local "SCRUM" company told me that they don't hold proper backlog grooming/refinement sessions: instead the team lead and the product owner discuss what to do next sprint, assign the tasks, then ask the developers to give estimates in hours.
Amazon emailed marketplace sellers to inform them it is not accepting new listings for the two media devices, and any existing listings will be removed at the end of October.
Amazon is telling *other stores* what they can sell. Amazon isn't just a store: They are a search engine for goods and an online payment processor. This is not like Best Buy refusing to sell a certain product. This is closer to Visa refusing to broker payments that involved competing products. Or perhaps Microsoft refusing to host web sites that offered products that compete with Microsoft Word. They may not be considered a monopoly in this space, but it sure looks anticompetitive.
It would be one thing if Amazon refused to sell the item themselves, but telling others they can't even list it on their service is a step further.
Also: Where does the term "packet based" come from? I don't remember seeing that in the press release. Just to clarify - TCP is stream based. So does the statement "packet based" mean it works with UDP but not TCP? I'm just trying to understand what is being claimed here.
I'm glad we agree to that then. So far Netflix is the only example anyone has provided. If there is another example I'd love to see it. In the meantime, all I have to go on is the articles I cited and my own knowledge of TCP.
No, you are not exaggerating what the feature does. Then citing examples of slightly similar features as proof that it works. I cited articles explaining how this works. You cited nothing, yet claim it as proof.
Hey Doug: See my reply to the AC above. It's clear we aren't all talking about the same thing. The parent posts and the article imply that the OS can automatically resume any network connection of any kind in any application. It does not do that. Then they run the Netflix app and go "see, it works!" when they are really testing the Netflix app, not the OS9 feature. What Apple provided is an efficient way for the app to switch networks. That's not the same thing. Try logging into your web banking, or play a Flash video, or a video game that needs a realtime connection. Everyone is mixing up a feature of the Netflix app with a feature of the OS.
Try it! Start a movie on Netflix with wifi on. Disable wifi while it plays. The movie will not even stutter.
That's not what they are talking about. That works because Netflix has created a protocol and an application that can do this. But the claim I am trying to refute is that this works with ANY application doing ANYTHING.
From the article:
That's helpful if you're in the middle of watching a video or some other task on the internet that you don't want interrupted by spotty Wi-Fi service.
From the post I replied to:
...And packets can be re-routed and resent. You might not be used to being able to swap and change like this on your existing phone. But that's the point, this is a new feature that other OSs don't do as yet.
So what BasilBrush, and the press releases from Apple imply, is that OS9 has a new feature no other OS has: it can transparently make streams continue, on another interface, with no support from the application software. I am trying to clarify that no, that is not what Apple did, because that is not possible. Showing that one app can do this doesn't show that the OS can do it for all apps.
Someone should try playing a fast action game online, a Flash video, or login to bank's bill pay web site.
Point closed. No magic. Clever programming by Netflix engineers
The article does not provide sufficient information to support meaningful discussion or criticism. The article does not provide justification or data, only high-level conclusions. Those conclusions only apply to a particular implementation of a program in a particular state, so no generalizations are made. It does not provide any links to information about he program or the research. Unless someone wants to do that research and provide it in the summary, there is simply nothing to see here.
This whole feature doesn't even sound possible. I can't find any details about how this feature is supposed to work, but there has to be more to it than "it magically opens another connection and it just works." The Wifi and Cellular connections have different IPs. The packets would suddenly be coming from a different IP address. TCP and UDP do not support that.
At the transport layer, suppose a phone is on Wifi at IP 1.1.1.1, is authenticated, and is receiving data. Suppose the cell connection is 5.5.5.5. There's no way to tell the server "Hey, I know I'm on 5.5.5.5, but I'm actually that guy who was on 1.1.1.1 a moment ago, so start routing my packets here." You can't pick-up a TCP stream and just continue it on another IP address. UDP won't work either, because it will ignore packets from 5.5.5.5 and keep sending to 1.1.1.1. That is why cellular voice connections use special protocols where the towers negotiate with each other. There is unique design considerations for such a hand-off and most protocols don't consider that.
Supposing the transport layer could solve this, the session layer won't allow it. When you log in to a network service, you send credentials and get back some kind of security token. Those tokens are usually not valid when sent from another IP address. That's a pretty common security best practice.
You would need the application to realize that the connection went bad, then renegotiate the connection on the other IP address by sending the login credentials and accepting a new security token. Then it would need to tell the server to continue the connection from the point it left off. The OS can't do that for you.
It seems to me that if the OS transparently sent the packets from another IP, even if the server somehow got those packets, and for some reason the TCP stack routed it to the application - which it would not - any well written service would probably assume it was a hack and log both connections out. Or at least ignore the second one.
I also wonder what the OS would do if both connections returned data? Now there's 2 response streams for 1 single outgoing stream.
The only way that I could see this working is if some other server in the middle is proxying all your data, and there is a way to tell the proxy about your new IP address.
Yes. I am having a hard time finding a good article on this, so I will attempt to explain. I'm a software guy with limited VLSI and electrical experience, so I bet 100 people will jump in and correct me on parts of this. But here goes...
I think the hope is that optical circuits would be lower resistance, be less susceptible to heat, not cause magnetic fields, and not act as transmitters or receivers.
When electricity passes through a wire, it experiences resistance. That resistance slows the signal and creates waste heat. "Slows the signal" means two things. One is that it takes longer for the current to flow to the destination. Two is that since current was lost to heat, it takes longer for the destination to sink enough current to turn on. As the wire heats, it also becomes a poorer conductor too.
Also, due to the way transistors work, they briefly short-circuit while they are switching. So the longer it takes for the current to build up at the gate's transistor, the longer it short circuits. Which produces heat too.
Another problem is that electricity in a wire creates a magnetic field. This creates more losses, but also can cause some of the electricity to jump to a neighboring wire. As transistors and wires get smaller, it becomes increasingly likely that signals will "short circuit" and jump to a neighboring wire.
Electronic circuits are also sources of, and susceptible to, external noise. A 2GHz CPU is a (weak) 2Ghz transmitter. And a 2Ghz transmitter could induce a voltage on wires within the CPU. I don't know how much of a problem this is though, since the wires in the CPU are very small.
Slashdot Mirror
Clarification:
Reading again, you meant changing one of the 4 sites to PV. Sorry. That approach wouldn't impact the efficiency of one of the solar thermal towers. But it would still pose the engineering cost problems.
I do wonder what the limitation is that makes it better to build 4 solar thermal plants rather than one big one. Maybe it can't handle that much heat? Maybe maintenance so they can shut one down and the others still function? Maybe aiming the mirrors over a larger distance is hard? Hmm...
Are you suggesting that they should remove some reflector mirrors and replace them with PV panels? Mixing technologies within a single site is poor economics in general, but with solar thermal it is particularly bad.
In general, mixing different technologies doubles the cost, makes maintenance harder, and removes the economy of scale. For example, they would need two different types of power infrastructure on one site. But in particular with solar thermal: more mirrors means more heat is focused onto the target, increasing power *and* temperature. Higher temperature = more efficiency. This same thing would happen with nuclear or coal or gas. Build one big coal plant, or one big gas plant. Building a 1/2 size gas plant and a 1/2 size coal plant on the same area would produce less power for a greater cost.
Nothing stops them from building a PV plant if that mix of fuel sources is better for them, but not at the same site.
Do iPhones not have a way to easily turn off mobile data? On Android it is right at the top.
From the article:
Making a password longer or including symbols was much more effective.
Yet so many systems limit password lengths and forbid special characters. Example: My bank is one of the top 20 largest banks in the US, and they do not allow special characters in their web banking.
1) Some systems limit which special characters you can use!
2) I bet people don't like to use parenthesis, brackets, or braces because seeing mismatched pairs seems "wrong." Or maybe it's just programmers.
Plus $30-50/month for the internet access itself. That brings you back to the price of premium cable.
The Wikipedia article provides no indication of a conspiracy theory. It has a section on it it that cites only one reporter, who later apologized for having suggested it. A Google search for "Ahmed Mohamed clock conspiracy theory" turns up articles pointing to extreme right-wing pundits with vague theories about a 9/11 conspiracy, but no actual concrete claims of any wrongdoing.
I take security even further than that: Even I don't know my own own PIN!
How about instead, they change the Windows crypto APIs to use OpenSSL?
Just because you are paranoid doesn't mean they aren't out to get you. But in this case, the author kinda is paranoid. He could use a course on web browsers and email.
The next morning, in my inbox, several spam e-mails urged me to invest in art. That was an easy one to figure out: I’d typed the name of the gallery into Google Maps.
It sounds like the author is alleging that Google gave his email address and marketing information to spammers. Is that true? Considering I have a gmail account that receives no spam at all, I think a more believable explanation is that he dropped his business card into a box somewhere, or signed-up on a list. In reality, 100% of my spam comes to the email address I have registered to my domain. My personal email gets nothing because I don't give it out.
Some people receive almost no spam. Other people get a 200:1 ratio of spam to real emails. Having done tech support, I can tell you by talking to someone for 5 minutes how much spam they get. Do they click on ads? Do they sign-up for stuff and give out their email? Do they play the lottery? Then they are in the high spam category. I bet a reporter is one of those people who gives out his contact information to absolutely everyone.
Another simple one to trace was the stream of invitations to drug and alcohol rehab centers that I’d been getting ever since I’d consulted an online calendar of Los Angeles–area Alcoholics Anonymous meetings. Since membership in AA is supposed to be confidential, these emails irked me.
Unless he created a dedicated email address specifically for the AA membership, he has no evidence of this. Again, more likely, he enaged in networking.
I don't even want to consider his example where his bluetooth somethingorother was transcribing his words and turning that into spam. That one is technically possible, but we just aren't there... yet.
With those complaints registered, many of the anecdotes in the story do make sense. A Google search triggered targeted ads on YouTube. Well yeah, Google owns both sites. This is one of the reasons people feared Google Plus: it was just *too* well integrated. I am just surprised that this is news to people at all. What do you think is in that 35 page license you clicked "accept" to in order to play that free Facebook game? Why do you think that flashlight app needs access to your contact list and the internet?
Let me answer my own question:
I didn't realize that entire organizations could get the prize. I thought it was just individuals. Doctor's without borders received the Nobel Peace Prize. Now I feel dumb.
That anecdote is super compelling, but after reading it I don't understand.
1) Who is the other Nobel Peace Prize winner you are referring to? The article mentions Joanne Liu, but she isn't a nobel winner. So who is it?
2) Obama didn't order that strike anyway. But I'll let that slide since he is commander-in-chief.
I have no interest in major league sports, but the idea of writing an algorithm that tracks top fantasy football players' decisions and tries to create a team based on that meta-information sounds really cool to me. It would be really neat to see how successful it could be while knowing nothing at all about the game itself.
And the problem with that is...what? Are you saying you want troopers to be inefficient? If the troopers knew that an area tended to have more murders, would you not want them to increase patrol efforts in that area?
Experience shows me that this problem is not limited to companies using JIRA. And some of the competing products aren't that great either. In my personal survey of local developers, the companies that love Agile the most aren't actually following the process: but they don't know or care. The ones that drank the kool-aid and try to stick to it function they way you described. The first group says things like "We do resources planning in Microsoft Project or on a big sheet of paper" and "We don't bother with points." A local "SCRUM" company told me that they don't hold proper backlog grooming/refinement sessions: instead the team lead and the product owner discuss what to do next sprint, assign the tasks, then ask the developers to give estimates in hours.
Check this part out:
Amazon emailed marketplace sellers to inform them it is not accepting new listings for the two media devices, and any existing listings will be removed at the end of October.
Amazon is telling *other stores* what they can sell. Amazon isn't just a store: They are a search engine for goods and an online payment processor. This is not like Best Buy refusing to sell a certain product. This is closer to Visa refusing to broker payments that involved competing products. Or perhaps Microsoft refusing to host web sites that offered products that compete with Microsoft Word. They may not be considered a monopoly in this space, but it sure looks anticompetitive.
It would be one thing if Amazon refused to sell the item themselves, but telling others they can't even list it on their service is a step further.
Also: Where does the term "packet based" come from? I don't remember seeing that in the press release. Just to clarify - TCP is stream based. So does the statement "packet based" mean it works with UDP but not TCP? I'm just trying to understand what is being claimed here.
I'm glad we agree to that then. So far Netflix is the only example anyone has provided. If there is another example I'd love to see it. In the meantime, all I have to go on is the articles I cited and my own knowledge of TCP.
No, you are not exaggerating what the feature does. Then citing examples of slightly similar features as proof that it works. I cited articles explaining how this works. You cited nothing, yet claim it as proof.
Hey Doug: See my reply to the AC above. It's clear we aren't all talking about the same thing. The parent posts and the article imply that the OS can automatically resume any network connection of any kind in any application. It does not do that. Then they run the Netflix app and go "see, it works!" when they are really testing the Netflix app, not the OS9 feature. What Apple provided is an efficient way for the app to switch networks. That's not the same thing. Try logging into your web banking, or play a Flash video, or a video game that needs a realtime connection. Everyone is mixing up a feature of the Netflix app with a feature of the OS.
Try it! Start a movie on Netflix with wifi on. Disable wifi while it plays. The movie will not even stutter.
That's not what they are talking about. That works because Netflix has created a protocol and an application that can do this. But the claim I am trying to refute is that this works with ANY application doing ANYTHING.
From the article:
That's helpful if you're in the middle of watching a video or some other task on the internet that you don't want interrupted by spotty Wi-Fi service.
From the post I replied to:
...And packets can be re-routed and resent. You might not be used to being able to swap and change like this on your existing phone. But that's the point, this is a new feature that other OSs don't do as yet.
So what BasilBrush, and the press releases from Apple imply, is that OS9 has a new feature no other OS has: it can transparently make streams continue, on another interface, with no support from the application software. I am trying to clarify that no, that is not what Apple did, because that is not possible. Showing that one app can do this doesn't show that the OS can do it for all apps.
Someone should try playing a fast action game online, a Flash video, or login to bank's bill pay web site.
Point closed. No magic. Clever programming by Netflix engineers
The article does not provide sufficient information to support meaningful discussion or criticism. The article does not provide justification or data, only high-level conclusions. Those conclusions only apply to a particular implementation of a program in a particular state, so no generalizations are made. It does not provide any links to information about he program or the research. Unless someone wants to do that research and provide it in the summary, there is simply nothing to see here.
This whole feature doesn't even sound possible. I can't find any details about how this feature is supposed to work, but there has to be more to it than "it magically opens another connection and it just works." The Wifi and Cellular connections have different IPs. The packets would suddenly be coming from a different IP address. TCP and UDP do not support that.
At the transport layer, suppose a phone is on Wifi at IP 1.1.1.1, is authenticated, and is receiving data. Suppose the cell connection is 5.5.5.5. There's no way to tell the server "Hey, I know I'm on 5.5.5.5, but I'm actually that guy who was on 1.1.1.1 a moment ago, so start routing my packets here." You can't pick-up a TCP stream and just continue it on another IP address. UDP won't work either, because it will ignore packets from 5.5.5.5 and keep sending to 1.1.1.1. That is why cellular voice connections use special protocols where the towers negotiate with each other. There is unique design considerations for such a hand-off and most protocols don't consider that.
Supposing the transport layer could solve this, the session layer won't allow it. When you log in to a network service, you send credentials and get back some kind of security token. Those tokens are usually not valid when sent from another IP address. That's a pretty common security best practice.
You would need the application to realize that the connection went bad, then renegotiate the connection on the other IP address by sending the login credentials and accepting a new security token. Then it would need to tell the server to continue the connection from the point it left off. The OS can't do that for you.
It seems to me that if the OS transparently sent the packets from another IP, even if the server somehow got those packets, and for some reason the TCP stack routed it to the application - which it would not - any well written service would probably assume it was a hack and log both connections out. Or at least ignore the second one.
I also wonder what the OS would do if both connections returned data? Now there's 2 response streams for 1 single outgoing stream.
The only way that I could see this working is if some other server in the middle is proxying all your data, and there is a way to tell the proxy about your new IP address.
Here's a SO post on the topic of changing IP addresses:
http://stackoverflow.com/quest...
Here's an academic paper on a proposed modification to TCP to allow this:
http://www.prevelakis.net/Pape...
Yes. I am having a hard time finding a good article on this, so I will attempt to explain. I'm a software guy with limited VLSI and electrical experience, so I bet 100 people will jump in and correct me on parts of this. But here goes...
I think the hope is that optical circuits would be lower resistance, be less susceptible to heat, not cause magnetic fields, and not act as transmitters or receivers.
When electricity passes through a wire, it experiences resistance. That resistance slows the signal and creates waste heat. "Slows the signal" means two things. One is that it takes longer for the current to flow to the destination. Two is that since current was lost to heat, it takes longer for the destination to sink enough current to turn on. As the wire heats, it also becomes a poorer conductor too.
Also, due to the way transistors work, they briefly short-circuit while they are switching. So the longer it takes for the current to build up at the gate's transistor, the longer it short circuits. Which produces heat too.
Another problem is that electricity in a wire creates a magnetic field. This creates more losses, but also can cause some of the electricity to jump to a neighboring wire. As transistors and wires get smaller, it becomes increasingly likely that signals will "short circuit" and jump to a neighboring wire.
Electronic circuits are also sources of, and susceptible to, external noise. A 2GHz CPU is a (weak) 2Ghz transmitter. And a 2Ghz transmitter could induce a voltage on wires within the CPU. I don't know how much of a problem this is though, since the wires in the CPU are very small.
Firewall != NAT