If we work with the axiom that at the thermodynamic limit is still only 40% efficient then the other 60% of the energy has to go into things other than generating motive force; things like: friction, noise, and heat.
Assuming we're at the thermodynamic limit, I'll assume we're also looking at minimal to no frictional losses. No friction will also cut down on noise from friction-based sources. This leaves that remaining 60% of energy being lost as heat. This heat could be used to run another heat engine using a source 60% as "hot" as the initial source. In theory we could stack these engines, losing 40% of our "heat" as "work" in each stage. Of course, at some point there won't be enough difference between the "hot" and "cold" sides of a heat engine to perform at all, so there is a limit. That being said, this is in no way a "perpetual motion" machine. The output of none of the engines is sufficient to run the engine itself, meaning that fuel needs to be consumed to supply out primary heat source.
This principle is used in other places than automotive engines. Steam locomotives frequently would use the "cold" low-pressure steam being exhausted from one set of drive cylinders to power a second set (http://en.wikipedia.org/wiki/Compound_locomotive). Obviously a steam locomotive was not at the thermodynamic limit, but even if that initial set of cylinders was at this limit, the exhaust would still have been steam under pressure, and potentially suited to driving another set of pistons to generate additional tractive effort.
I hear this quite frequently, and I can't understand the mindset that actually finds it to be a good piece of advice. If I cannot find a candidate I like, why should I vote for one who repulses me just because he's less distasteful than the alternative. If my options for food were a spoiled egg salad sandwich, or botulism-infested soup why would I chose either of them? I would do without until I found something not only less distasteful than the alternatives, but also of a minimum standard of acceptability if not more than that.
It is common wisdom to vote for the lesser of two evils, but when the choice is 85% evil and 84.999% evil, why would I accept 84.999% just because it's lower? Why can't I demand no more than 45% evil?
In short. Don't vote for the candidate you dislike the least, vote for a candidate who you actually like. If you can't find a candidate you can accept, then vote third party. If there are no third party candidates that you can accept, then write in. If you can't think of anyone to write in, then petition for the race to be invalidated and that new candidates be selected and run. If there are no acceptable choices, don't just accept what is offered.
Actually, i=i++ should always increment. let's take the first case
set i to 0; set i to 0 then increment. whereas the second case is
set i to 0; increment i to 0 then set i to i.
There should be no method of evaluating this function that returns 0 (or whatever our initial value was).
The problem is hardly insoluble. In fact, most undersea fiber cable has a layer of copper cladding which is used to deliver power to the booster segments. Obviously a piece of fiber with a copper cladding would cost more than a piece of fiber without, and this is the reason we don't see this practice used in the majority of overland installations. However, if there was sufficient economic advantage to be gained from power-capable fiber, I'm sure some companies would begin to consider it.
While I agree it was a good movie, and I'm going to get shot all to hell for this comment, I really didn't like this portrayal of The Joker. That and the whole movie screaming from one action scene to another with little to no character interaction just left it feeling shallow and not fulfilling, although slightly more than mildly amusing.
The "sound" in that article was detected by using Chandra to very carefully measure the of the gas in the Perseus galaxy cluster. There's no indication that the sound wave itself is crossing the 250 million light years to Earth. However, the article repeatedly mentions the sound waves imparting the energy into the surrounding gas clouds and causing the variations in brightness.
If the article's terminology is correct, then the gas that makes up these portions of the Perseus cluster must be dense enough to support the propagation of sound waves through it. Unfortunately, this doesn't mean that sound can propagate through what we normally think of as the interstellar medium, merely that this cluster is unusually dense.
If the article is not correct, or is improperly interpreting the original material, then some other force (such as gravity) may be imparting this wave-like motion to the surrounding gas clouds, and the imparted motion may have all the apparent characteristics of a sound wave resonating at B flat, 57 octaves below middle C.
Either way, however, there's no indication that sound waves from a remote celestial object can propagate to Earth from other planets in this solar system, much less indications that such can occur from even more distant sources.
Some people do admit it. I drive a light truck, and when I was purchasing the vehicle I had no interest in small cars or full sized SUVs. I wanted something that I liked, and the added advantage that I can't have more than one passenger has saved me from being a taxi service for people I know.
Sure I don't haul cargo, no I don't tow things, yes a tiny little car could get me where I want to go. On the other hand, I get what I still consider an acceptable gas mileage. Oh, there are rationalizations too, but the primary reason behind getting the truck was selfishness: it's what I wanted.
An AC has already pointed this out, but "Primary Storage" in the typical computer model is what we would consider RAM. Hard Drives and other "storage" media are considered to be "Secondary Storage". Primary Storage also consists of cache, and I believe processor registers. Removable media, is often called "Offline Storage" or "Tertiary Storage"
"Good, then YOU program YOUR WAP to ask for a password"
Why should I have to?
You should have to because a wifi router in its default state specifically grants access to any compatible device. The compatible devices may even connect without even properly informing the device owner what AP it has connected to, and additionally it may well be impossible to tell -which- of the numerous "default" or "linksys" APs is the one granting access to the device. However, if you take 5 minutes to connect to your AP, set the SSID to "Call me For Access: ###-####" and set a password you will find that: devices will no longer automatically connect without user intervention, users of those devices will have some idea of who to talk to for access, and anyone connecting without getting that permission from you is obviously subverting your intention for that AP. For even greater clarity, you could change the SSID to "Private" or some variant thereof, or even disable SSID broadcast. These actions clearly and unambiguously present your intentions to anyone who may be attempting to connect, these actions prevent random, unintended connections, and these actions are not difficult to perform for anyone willing to look at a 1-page instruction sheet and follow a short wizard.
Obviously -you- intend that, no matter what the settings on your wireless AP, no one but you access your network without your permission. There are known, easy methods to clearly present this intention to people who might wish to connect. The very fact that a user purchases a wireless router, connects that router to their network, verifies that router grants their wireless devices connectivity, and leaves that router configured to broadcast that it is unsecured, open, and ready-to-connect does not unambiguously state an intent to prevent access.
I agree that a "default" router may also not be unambiguously stating an intent to provide access, but given that many devices will automatically try to connect to the closest, most powerful, unlocked AP we have to assume that an unlocked, broadcasting AP is commonly seen as granting permission to connect.
I don't want to use your stuff; I'm quite happy with using my own wifi, and I'm quite happy to lock down my AP to prove that I don't want to share my bandwidth with the world. On the other side of the coin, I have in the past been quite happy to just plug my router into my network without configuring it, and just letting the world leech. How am I supposed to know that you want me to ask to use your default, AP when every device I have will try to connect without even asking me, and when if I want to grant public access I just leave mine set to default?
Please, if you don't want me to access your network, just set a WEP/WPA password or set your SSID, or even disable it. Just give me one clear unambiguous clue, using the tools in place for that purpose, telling me that AP is off limits. Do that, and I'll promise that if I ever run an extension cord onto your property, I'll put a sign on it that says: "default configuration, unlocked," or one that says: "Please don't use this. Thank you."
I assume you're referring to the line: "Now witness the firepower of this fully ARMED and OPERATIONAL battle station!" Which only indicates that the Emperor ordered the Deathstar II's weapon systems to be completed before the rest of the station was. There's no indication that the second station was built at the same time as the first, and then partially dismantled so it would look like it was under contstruction. Additionally the variances in the main weapon system on the two Death Stars indicates some shift in the technology between the two.
I do admit that the Emperor calling the Deathstar II "fully operational" is rater misleading, as it was obviously missing large portions of its interior. However, I believe most people who watch the movie take that statement in context with what we see of the Deathstar II and understand that the Emperor is speaking purely in terms of offensive systems, and possibly TIE Fighter squadrons.
How do you know that tidally locked planets are commonplace? There are none in our system.
None, except for Venus...
According to Wikipedia:
Venus orbits the Sun at an average distance of about 108 million km, and completes an orbit every 224.65 days. and
Venus rotates once every 243 days--by far the slowest rotation period of any of the major planets. Which, while interesting and most likely the result of strong tidal forces acting on the thick venutian atmosphere, is somewhat different from actually being tidally locked with the sun.
Parent is dead on. You should be allowed to not wear a seatbelt if and only if you pay a highly financially sound insurance company to cover all plausible costs for your medical care if you get in an accident - and all disability payments you might get for the same reason.
Or if you agree that you can be euthanised and have your various organs harvested and distributed to those who can pay their medical bills or have the appropriate insurance policy.
According to posters who have read the article, there is already a 90% to 99% false positive rate. Out of 70,000 people singled out for secondary screening by this process, 600 to 700 were arrested. Of those arrested, charges ranged from drug possession to "weapons violations" and outstanding warrants.
99 essentially innocent people were thoroughly searched so that 1 person with an outstanding warrant- a person who had already purchased a plane ticket, shown ID, been granted a boarding pass, and made it through the initial screening process (x-ray machine, metal detector)- could be arrested.
...then imagine walking into a Christian fundamentalist church as an atheist.
I've done this except it wasn't a fundamentalist church, I was there with regulars, and no one knew I was an atheist. On the whole, it was a rather average collection of average people trying to be pleasant. I assume that if I had gone in brandishing my atheism like a weapon the reaction would have been different.
It only takes 1 to take out an entire city and while 200 is a comparatively small number, it's more than enough to destroy the entire world.
While I agree in principle that beyond a certain number, more nukes is a meaningless gesture, calling 200 nukes "enough to destroy the entire world" is not entirely accurate.
The largest nuclear weapon ever detonated, Tsar Bomba, was calculated by the US to be 57 Megatons and officially reported by all Russian sources since 1991 as 50 Megatons. The fireball from this blast would cause third degree burns at a range of 100 kilometers from the actual explosion, with additional thermal damage further out.
If we assume all 200 weapons in question are of similar class to Tsar Bomba, and all 200 were simultaniously detonated, the total yield would be on the order of 5000 megatons, or a mere 5 gigatons of TNT. In Contrast, the asteroid impact which produced the Chicxulub Crater released an estimated 5x10^23 joules of energy, or approximately the same as 100 Teratons or 100,000 gigatons. Admittedly, the event which formed the Cicxulub Crater could be considered "World Destroying" in the sense that very little on the surface would remain, but the energy released by the simultanious detonation of 200 of the largest nuclear devices ever produced would generate a mere one half of one percent of such an impactor.
Another way to consider it is: if 1 thermonuclear device of 50 megatons would completely annihilate one city, then 200 will account for 200 cities and their surrounding areas. While the destruction of 200 cities would be incredibly disruptive and even catastrophic in terms of economic, military, and ecological impact not to mention the vast death toll, It would hardly result in the destruction of the entire world.
The battery seems to be uncompromised until the black stuff appears, so I would assume the black stuff is a pretty good indication of why we don't puncture Lithium Polymer batteries.
Slashdot Mirror
If we work with the axiom that at the thermodynamic limit is still only 40% efficient then the other 60% of the energy has to go into things other than generating motive force; things like: friction, noise, and heat.
Assuming we're at the thermodynamic limit, I'll assume we're also looking at minimal to no frictional losses. No friction will also cut down on noise from friction-based sources. This leaves that remaining 60% of energy being lost as heat. This heat could be used to run another heat engine using a source 60% as "hot" as the initial source. In theory we could stack these engines, losing 40% of our "heat" as "work" in each stage. Of course, at some point there won't be enough difference between the "hot" and "cold" sides of a heat engine to perform at all, so there is a limit. That being said, this is in no way a "perpetual motion" machine. The output of none of the engines is sufficient to run the engine itself, meaning that fuel needs to be consumed to supply out primary heat source.
This principle is used in other places than automotive engines. Steam locomotives frequently would use the "cold" low-pressure steam being exhausted from one set of drive cylinders to power a second set (http://en.wikipedia.org/wiki/Compound_locomotive). Obviously a steam locomotive was not at the thermodynamic limit, but even if that initial set of cylinders was at this limit, the exhaust would still have been steam under pressure, and potentially suited to driving another set of pistons to generate additional tractive effort.
baby seal-killing pirates
Infant buccaneers who slaughter cold-water marine mammals that come onshore to breed?
...Vote for the one you dislike the least.
I hear this quite frequently, and I can't understand the mindset that actually finds it to be a good piece of advice. If I cannot find a candidate I like, why should I vote for one who repulses me just because he's less distasteful than the alternative. If my options for food were a spoiled egg salad sandwich, or botulism-infested soup why would I chose either of them? I would do without until I found something not only less distasteful than the alternatives, but also of a minimum standard of acceptability if not more than that.
It is common wisdom to vote for the lesser of two evils, but when the choice is 85% evil and 84.999% evil, why would I accept 84.999% just because it's lower? Why can't I demand no more than 45% evil?
In short. Don't vote for the candidate you dislike the least, vote for a candidate who you actually like. If you can't find a candidate you can accept, then vote third party. If there are no third party candidates that you can accept, then write in. If you can't think of anyone to write in, then petition for the race to be invalidated and that new candidates be selected and run. If there are no acceptable choices, don't just accept what is offered.
Wow, I sound like a crackpot, don't I?
damn me for not previewing...
whereas the second case is
set i to 0; increment i to 1 then set i to i.
Although, I think you're right and the correct answer is "This behavior is undefined"
Actually, i=i++ should always increment.
let's take the first case
set i to 0; set i to 0 then increment.
whereas the second case is
set i to 0; increment i to 0 then set i to i.
There should be no method of evaluating this function that returns 0 (or whatever our initial value was).
Third, open source is completely OFF TOPIC in this discussion!!
This sis Slashdot. Open source is always on topic. Just like bashing the RIAA.
I think you meant:
Off Topic? This Is SLASHDOT!
/me hangs head in shame
The problem is hardly insoluble. In fact, most undersea fiber cable has a layer of copper cladding which is used to deliver power to the booster segments. Obviously a piece of fiber with a copper cladding would cost more than a piece of fiber without, and this is the reason we don't see this practice used in the majority of overland installations. However, if there was sufficient economic advantage to be gained from power-capable fiber, I'm sure some companies would begin to consider it.
I can tell you live in Phoenix.
While I agree it was a good movie, and I'm going to get shot all to hell for this comment, I really didn't like this portrayal of The Joker. That and the whole movie screaming from one action scene to another with little to no character interaction just left it feeling shallow and not fulfilling, although slightly more than mildly amusing.
That must be the hovercraft of shame!?
Was it full of eels?
"Insightful" gives karma, "Funny" doesn't. That's why you sometimes see Insightful posts moderated funny.
The "sound" in that article was detected by using Chandra to very carefully measure the of the gas in the Perseus galaxy cluster. There's no indication that the sound wave itself is crossing the 250 million light years to Earth. However, the article repeatedly mentions the sound waves imparting the energy into the surrounding gas clouds and causing the variations in brightness.
If the article's terminology is correct, then the gas that makes up these portions of the Perseus cluster must be dense enough to support the propagation of sound waves through it. Unfortunately, this doesn't mean that sound can propagate through what we normally think of as the interstellar medium, merely that this cluster is unusually dense.
If the article is not correct, or is improperly interpreting the original material, then some other force (such as gravity) may be imparting this wave-like motion to the surrounding gas clouds, and the imparted motion may have all the apparent characteristics of a sound wave resonating at B flat, 57 octaves below middle C.
Either way, however, there's no indication that sound waves from a remote celestial object can propagate to Earth from other planets in this solar system, much less indications that such can occur from even more distant sources.
Some people do admit it. I drive a light truck, and when I was purchasing the vehicle I had no interest in small cars or full sized SUVs. I wanted something that I liked, and the added advantage that I can't have more than one passenger has saved me from being a taxi service for people I know.
Sure I don't haul cargo, no I don't tow things, yes a tiny little car could get me where I want to go. On the other hand, I get what I still consider an acceptable gas mileage. Oh, there are rationalizations too, but the primary reason behind getting the truck was selfishness: it's what I wanted.
An AC has already pointed this out, but "Primary Storage" in the typical computer model is what we would consider RAM. Hard Drives and other "storage" media are considered to be "Secondary Storage". Primary Storage also consists of cache, and I believe processor registers. Removable media, is often called "Offline Storage" or "Tertiary Storage"
The relevant Wiki article is: Computer Storage; specifically the sections: Primary Storage, and Secondary Storage.
The overall point I'm trying to make here is, we're talking gigabytes, and it's still very interesting.
Can I get this on a t-shirt? Why, are you a model?
C-M C-Soviet
You should have to because a wifi router in its default state specifically grants access to any compatible device. The compatible devices may even connect without even properly informing the device owner what AP it has connected to, and additionally it may well be impossible to tell -which- of the numerous "default" or "linksys" APs is the one granting access to the device. However, if you take 5 minutes to connect to your AP, set the SSID to "Call me For Access: ###-####" and set a password you will find that: devices will no longer automatically connect without user intervention, users of those devices will have some idea of who to talk to for access, and anyone connecting without getting that permission from you is obviously subverting your intention for that AP.
For even greater clarity, you could change the SSID to "Private" or some variant thereof, or even disable SSID broadcast. These actions clearly and unambiguously present your intentions to anyone who may be attempting to connect, these actions prevent random, unintended connections, and these actions are not difficult to perform for anyone willing to look at a 1-page instruction sheet and follow a short wizard.
Obviously -you- intend that, no matter what the settings on your wireless AP, no one but you access your network without your permission. There are known, easy methods to clearly present this intention to people who might wish to connect. The very fact that a user purchases a wireless router, connects that router to their network, verifies that router grants their wireless devices connectivity, and leaves that router configured to broadcast that it is unsecured, open, and ready-to-connect does not unambiguously state an intent to prevent access.
I agree that a "default" router may also not be unambiguously stating an intent to provide access, but given that many devices will automatically try to connect to the closest, most powerful, unlocked AP we have to assume that an unlocked, broadcasting AP is commonly seen as granting permission to connect.
I don't want to use your stuff; I'm quite happy with using my own wifi, and I'm quite happy to lock down my AP to prove that I don't want to share my bandwidth with the world. On the other side of the coin, I have in the past been quite happy to just plug my router into my network without configuring it, and just letting the world leech. How am I supposed to know that you want me to ask to use your default, AP when every device I have will try to connect without even asking me, and when if I want to grant public access I just leave mine set to default?
Please, if you don't want me to access your network, just set a WEP/WPA password or set your SSID, or even disable it. Just give me one clear unambiguous clue, using the tools in place for that purpose, telling me that AP is off limits. Do that, and I'll promise that if I ever run an extension cord onto your property, I'll put a sign on it that says: "default configuration, unlocked," or one that says: "Please don't use this. Thank you."
I assume you're referring to the line: "Now witness the firepower of this fully ARMED and OPERATIONAL battle station!" Which only indicates that the Emperor ordered the Deathstar II's weapon systems to be completed before the rest of the station was. There's no indication that the second station was built at the same time as the first, and then partially dismantled so it would look like it was under contstruction. Additionally the variances in the main weapon system on the two Death Stars indicates some shift in the technology between the two.
I do admit that the Emperor calling the Deathstar II "fully operational" is rater misleading, as it was obviously missing large portions of its interior. However, I believe most people who watch the movie take that statement in context with what we see of the Deathstar II and understand that the Emperor is speaking purely in terms of offensive systems, and possibly TIE Fighter squadrons.
None, except for Venus...
According to Wikipedia: Venus orbits the Sun at an average distance of about 108 million km, and completes an orbit every 224.65 days. and Venus rotates once every 243 days--by far the slowest rotation period of any of the major planets. Which, while interesting and most likely the result of strong tidal forces acting on the thick venutian atmosphere, is somewhat different from actually being tidally locked with the sun.
Or if you agree that you can be euthanised and have your various organs harvested and distributed to those who can pay their medical bills or have the appropriate insurance policy.
According to posters who have read the article, there is already a 90% to 99% false positive rate. Out of 70,000 people singled out for secondary screening by this process, 600 to 700 were arrested. Of those arrested, charges ranged from drug possession to "weapons violations" and outstanding warrants.
99 essentially innocent people were thoroughly searched so that 1 person with an outstanding warrant- a person who had already purchased a plane ticket, shown ID, been granted a boarding pass, and made it through the initial screening process (x-ray machine, metal detector)- could be arrested.
...then imagine walking into a Christian fundamentalist church as an atheist.
I've done this except it wasn't a fundamentalist church, I was there with regulars, and no one knew I was an atheist. On the whole, it was a rather average collection of average people trying to be pleasant. I assume that if I had gone in brandishing my atheism like a weapon the reaction would have been different.
It only takes 1 to take out an entire city and while 200 is a comparatively small number, it's more than enough to destroy the entire world.
While I agree in principle that beyond a certain number, more nukes is a meaningless gesture, calling 200 nukes "enough to destroy the entire world" is not entirely accurate.
The largest nuclear weapon ever detonated, Tsar Bomba, was calculated by the US to be 57 Megatons and officially reported by all Russian sources since 1991 as 50 Megatons. The fireball from this blast would cause third degree burns at a range of 100 kilometers from the actual explosion, with additional thermal damage further out.
If we assume all 200 weapons in question are of similar class to Tsar Bomba, and all 200 were simultaniously detonated, the total yield would be on the order of 5000 megatons, or a mere 5 gigatons of TNT. In Contrast, the asteroid impact which produced the Chicxulub Crater released an estimated 5x10^23 joules of energy, or approximately the same as 100 Teratons or 100,000 gigatons. Admittedly, the event which formed the Cicxulub Crater could be considered "World Destroying" in the sense that very little on the surface would remain, but the energy released by the simultanious detonation of 200 of the largest nuclear devices ever produced would generate a mere one half of one percent of such an impactor.
Another way to consider it is: if 1 thermonuclear device of 50 megatons would completely annihilate one city, then 200 will account for 200 cities and their surrounding areas. While the destruction of 200 cities would be incredibly disruptive and even catastrophic in terms of economic, military, and ecological impact not to mention the vast death toll, It would hardly result in the destruction of the entire world.
Fingernails?! I nmy day we would have killed for fingernails, but the guys with the nails also had the big sticks.
The battery seems to be uncompromised until the black stuff appears, so I would assume the black stuff is a pretty good indication of why we don't puncture Lithium Polymer batteries.