Funny. I didn't ever mention any of these things that people are taking offense at. It's just a/. phenomenon that no one answers the question asked and instead rails on something possibly quite unrelated.
P.S. the really effective and sophisticated way to encrypt things is to use spelling which depends on the context. For example, spelling something as "enctypted".
I send emails which I wouldn't necessarily want shown to everyone, but very, very few of them really SHOULD be enctypted. I have a feeling that the vast majority of people who use encryption systems for their emails really don't need them -- they're just used to get a cool-looking "this email has been encrypted; here's my fingerprint" block in the signature. It's fun to *play* at being a spy, or thinking I have super-important stuff which shouldn't be seen by undeserving eyes, but it's mainly just that: fun.
I check the various sun tracking sites and almost without fail I will find that there was some kind of burst of solar activity going on around that time.
Ah, yes. My father has complained of the same thing, and his father before him. Extrapolating back, the world must've been a fucking bright place several thousands of years ago.
Spam almost pushed my mom off the 'net for good. She was so upset at all the spam she gets in her email every day that she was just about to stop using email at all, when I got home for Christmas. And she's not getting pron spam; she's getting spam from "rolex" manufacturers, and -- get this -- yarn companies, because she's ordered yarn online before (and asked to NOT be put on any mailing lists; I was there when she did, and she shouldn't be on any distributed mass-emailing lists).
I told her to calm down, and give me a couple of hours (she's on dial-up, which is good for me, because it meant very little spyware). I did just what many of the people here have done, and suggested.
She had XP SP2 installed (ordered the CDs from Microsquish), so the firewalling was sufficient. I simply downloaded and ran SpyBot, AdAware, and AVGAntiVirus (love the free version!) and tried to get the really nasty crap off the computer.
Then I downloaded Thunderbird, had it import all of her contacts and emails from Outlook (it didn't deal with "groups" lists of emails very well, but did everything else perfectly), and showed her how it's going to be a little (but not much) different.
She was actually looking *forward* to getting some spam, so she could train the filters, and sometimes emails me saying, "I got such-and-such junk, but that program you put on knew it was spam, and put it in the Junk folder for me! And all the good stuff is coming through!"
Let me respond to my own post, since so many people are hyped up about this. I will clarify what I meant (and why I stated that I'm not familiar with wireless technology), and then let people decide.
First, in my defense: Read Griffiths' Electrodynamics, chapters 2 and/or 3. Pay special attention to the points where he states that at "low frequencies"--which for our problem means things below the THz range--a cavity surrounded by a conductor is not influenced by electrical fields from outside, but that the outside world is NOT shielded by ANY net charge within the cavity. Similarly, see http://samizdat.mines.edu/jackson/main.pdf or http://courses.science.fau.edu/~rjordan/busters_22/answers_1.htm#Ex_9
Now, in regards to people's arguments about microwave ovens and so forth: Yes, of course they're shielded, both with the (usually unbroken) metal casing around the sides and top of the oven, and the mesh or perforated metal plate on the door. And, yes, they produce roughly the same (dipole) radiation patterns as a wireless transmitter of some sort. The fact that the shielding isn't perfect (breaks in it, sometimes not thick enough for the [very low, admittedly] frequency of the radiation emitted) leads to interference, often on wireless networks. If the shielding were better (as, for example, a nice conducting shield all around the thing, of thick enough material that skin depths don't come into play), then there would be NO escaping radiation, just as people say a Faraday cage should work. All of this I agree to. My statement that "any radiation produced by the thing inside the conductive shield will get out just fine" is WRONG, and I'm glad that people jumped on it.
My mistake was using the word ANY. Dipole radiation (such as from an antenna) or quadrupole radiation (crossed antennae, e.g.) and higher moment radiations should all be blocked from escaping from a perfect faraday cage. But monopole radiation, as from a net charge of some type inside the shield WILL escape, there's no getting around that. And I'm pretty sure (correct me on this if I'm wrong; I'm sure people will!) that most, if not all, electrical appliances which draw their power from an external source (i.e. wires, not a battery) will have, at a given moment, a net charge reflecting their states. This is IF these things are not perfectly grounded (as all appliances should be!). If this is the case, then the shield, although effective at knocking down the dipole and higher moment fields, couldn't do anything about monopole fields.
Can someone get a matched pair of walkie talkies, wrap one of them well in aluminum foil, and try this out?
Sorry, but the wikipedia article on Faraday cages is mistaken -- read any reputable text on electrostatics and/or Laplace's Equation, or, better yet, just think about (or use, if you have access to one!) a van de Graaf generator. Conducting shell, large charge inside. Tell me that the outside world is shielded from that charge!
Oh, god, I went for almost two weeks without having that stuck in my head. You, ma'am (just going from the name, here), are an utter bastard! (But I totally respect that.)
It's not difficult at all. An electrical conductor will rearrange its free charges so as to make the potential within it a constant, and (+/-, depending on your gauge definition) grad(potential) gives your electrical field: thus, no field within an *empty* cavity within a conductive shield. (Can also be shown from Gauss' Law, and integrating around any closed loop which partially goes through the cavity, and partially through the conductor.)
However, if you introduce some non-zero field into the cavity (as, for example, introducting some charge through a wire from the ground into the house), the shield will STILL rearrange its charges to neutralize the potential gradient (field) within the conductor itself. But this rearrangement leaves surface charges on the outer surface, which act as just a "distributed" version of whatever charge is in the cavity.
Your argument is one that undergrads love to use on their professors, but the uniqueness theorems of electrostatics render it null and void. There IS a significant difference between the "inside" and "outside" -- inside the shell, any field line is guaranteed to terminate on a piece of shell; outside the shell, only a tiny subset of field lines have to terminate on the shell -- the others can go to infinity without ever hitting a conductor. (But see Feynman's and Wheeler's arguments about radiation reaction forces for a somewhat more complicated explanation.)
I'm not really familiar with wireless technology, but I DO know that a conductive shield around something will protect the thing inside it from extraneous electrical fields (as long as their frequency isn't super-high), but that any radiation produced by the thing inside the conductive shield will get out just fine. Because wireless things are on carriers of "only" several GHz, the increased size of the shield (as opposed to the normal antenna or whatever) shouldn't make any difference to phasings.
I guess that most people have their houses land-lined (or satellited, or whatever), and then use wireless networks to distribute bandwidth _within_ the house, right? Because putting a shield around such a house would only serve to keep outside signals from getting in, not inside signals from getting out. Of course, if protocols usually work with a "give-and-take" system, then this would cut off part of that, and people wouldn't be able to connect to your wireless system, but they _would_ be able to eavesdrop.
Erm... I'm pretty sure you mean that you got sucked into maths from physics, but, of course, physics uses manifolds and differential geometry ALL the time, especially if you're going to study Chaos or anything having to do with relativity.
Slashdot Mirror
Sweet. I can sit back and let that sucker go STRAIGHT to the pr0n. clickety, clickety
Threesomes, lesbian orgies, it's all fun and games.
...until someone loses an eye.
I believe you left out the part which reads
[...]some people label him as a wacko conservative, and other label him as a wacko liberal.
It seems to me that those either totally cancel each other, or he's 2X wacko.
Still a fun writer. Except for the thorougly shitty one about time travel. *gag*
You seem to be implying that Bill Gates and some sort of rainbow thing has caused it...
This thing was run on so many PCs. They obviously took the simulation itself into account -- good job!
What -- you're now a slashdot editor?
... but then -- OOH! Shiny!
Pew research says "Whoever smelt it, dealt it."
Funny. I didn't ever mention any of these things that people are taking offense at. It's just a /. phenomenon that no one answers the question asked and instead rails on something possibly quite unrelated.
P.S. the really effective and sophisticated way to encrypt things is to use spelling which depends on the context. For example, spelling something as "enctypted".
I send emails which I wouldn't necessarily want shown to everyone, but very, very few of them really SHOULD be enctypted. I have a feeling that the vast majority of people who use encryption systems for their emails really don't need them -- they're just used to get a cool-looking "this email has been encrypted; here's my fingerprint" block in the signature. It's fun to *play* at being a spy, or thinking I have super-important stuff which shouldn't be seen by undeserving eyes, but it's mainly just that: fun.
Let the flamin' begin.
[...]the impact of denying access to techniques and logarithms effectively shuts out competition[...]
Ah, yes, the old "don't let them look up logarithms in a table" trick.
I check the various sun tracking sites and almost without fail I will find that there was some kind of burst of solar activity going on around that time.
Around here, we call that "daylight".
"Let's go shopping!"
Aerosmith has to re-record their classic, to be renamed "Love in a Nanotube-Tethered Space Elevator".
Ah, yes. My father has complained of the same thing, and his father before him. Extrapolating back, the world must've been a fucking bright place several thousands of years ago.
Spam almost pushed my mom off the 'net for good. She was so upset at all the spam she gets in her email every day that she was just about to stop using email at all, when I got home for Christmas. And she's not getting pron spam; she's getting spam from "rolex" manufacturers, and -- get this -- yarn companies, because she's ordered yarn online before (and asked to NOT be put on any mailing lists; I was there when she did, and she shouldn't be on any distributed mass-emailing lists).
I told her to calm down, and give me a couple of hours (she's on dial-up, which is good for me, because it meant very little spyware). I did just what many of the people here have done, and suggested.
She had XP SP2 installed (ordered the CDs from Microsquish), so the firewalling was sufficient. I simply downloaded and ran SpyBot, AdAware, and AVGAntiVirus (love the free version!) and tried to get the really nasty crap off the computer.
Then I downloaded Thunderbird, had it import all of her contacts and emails from Outlook (it didn't deal with "groups" lists of emails very well, but did everything else perfectly), and showed her how it's going to be a little (but not much) different.
She was actually looking *forward* to getting some spam, so she could train the filters, and sometimes emails me saying, "I got such-and-such junk, but that program you put on knew it was spam, and put it in the Junk folder for me! And all the good stuff is coming through!"
Dog bless Thunderbird.
Let me respond to my own post, since so many people are hyped up about this. I will clarify what I meant (and why I stated that I'm not familiar with wireless technology), and then let people decide.
2 /answers_1.htm#Ex_9
First, in my defense: Read Griffiths' Electrodynamics, chapters 2 and/or 3. Pay special attention to the points where he states that at "low frequencies"--which for our problem means things below the THz range--a cavity surrounded by a conductor is not influenced by electrical fields from outside, but that the outside world is NOT shielded by ANY net charge within the cavity. Similarly, see http://samizdat.mines.edu/jackson/main.pdf or http://courses.science.fau.edu/~rjordan/busters_2
Now, in regards to people's arguments about microwave ovens and so forth: Yes, of course they're shielded, both with the (usually unbroken) metal casing around the sides and top of the oven, and the mesh or perforated metal plate on the door. And, yes, they produce roughly the same (dipole) radiation patterns as a wireless transmitter of some sort. The fact that the shielding isn't perfect (breaks in it, sometimes not thick enough for the [very low, admittedly] frequency of the radiation emitted) leads to interference, often on wireless networks. If the shielding were better (as, for example, a nice conducting shield all around the thing, of thick enough material that skin depths don't come into play), then there would be NO escaping radiation, just as people say a Faraday cage should work. All of this I agree to. My statement that "any radiation produced by the thing inside the conductive shield will get out just fine" is WRONG, and I'm glad that people jumped on it.
My mistake was using the word ANY. Dipole radiation (such as from an antenna) or quadrupole radiation (crossed antennae, e.g.) and higher moment radiations should all be blocked from escaping from a perfect faraday cage. But monopole radiation, as from a net charge of some type inside the shield WILL escape, there's no getting around that. And I'm pretty sure (correct me on this if I'm wrong; I'm sure people will!) that most, if not all, electrical appliances which draw their power from an external source (i.e. wires, not a battery) will have, at a given moment, a net charge reflecting their states. This is IF these things are not perfectly grounded (as all appliances should be!). If this is the case, then the shield, although effective at knocking down the dipole and higher moment fields, couldn't do anything about monopole fields.
Can someone get a matched pair of walkie talkies, wrap one of them well in aluminum foil, and try this out?
Sorry, but the wikipedia article on Faraday cages is mistaken -- read any reputable text on electrostatics and/or Laplace's Equation, or, better yet, just think about (or use, if you have access to one!) a van de Graaf generator. Conducting shell, large charge inside. Tell me that the outside world is shielded from that charge!
Oh, god, I went for almost two weeks without having that stuck in my head. You, ma'am (just going from the name, here), are an utter bastard! (But I totally respect that.)
If I were a dwarf on the Discworld, I'd know how to spell "Discworld". :P
It's not difficult at all. An electrical conductor will rearrange its free charges so as to make the potential within it a constant, and (+/-, depending on your gauge definition) grad(potential) gives your electrical field: thus, no field within an *empty* cavity within a conductive shield. (Can also be shown from Gauss' Law, and integrating around any closed loop which partially goes through the cavity, and partially through the conductor.)
However, if you introduce some non-zero field into the cavity (as, for example, introducting some charge through a wire from the ground into the house), the shield will STILL rearrange its charges to neutralize the potential gradient (field) within the conductor itself. But this rearrangement leaves surface charges on the outer surface, which act as just a "distributed" version of whatever charge is in the cavity.
Your argument is one that undergrads love to use on their professors, but the uniqueness theorems of electrostatics render it null and void. There IS a significant difference between the "inside" and "outside" -- inside the shell, any field line is guaranteed to terminate on a piece of shell; outside the shell, only a tiny subset of field lines have to terminate on the shell -- the others can go to infinity without ever hitting a conductor. (But see Feynman's and Wheeler's arguments about radiation reaction forces for a somewhat more complicated explanation.)
I'm fairly certain you mean the song "Spam Spam Spam Spam".
I'm not really familiar with wireless technology, but I DO know that a conductive shield around something will protect the thing inside it from extraneous electrical fields (as long as their frequency isn't super-high), but that any radiation produced by the thing inside the conductive shield will get out just fine. Because wireless things are on carriers of "only" several GHz, the increased size of the shield (as opposed to the normal antenna or whatever) shouldn't make any difference to phasings.
I guess that most people have their houses land-lined (or satellited, or whatever), and then use wireless networks to distribute bandwidth _within_ the house, right? Because putting a shield around such a house would only serve to keep outside signals from getting in, not inside signals from getting out. Of course, if protocols usually work with a "give-and-take" system, then this would cut off part of that, and people wouldn't be able to connect to your wireless system, but they _would_ be able to eavesdrop.
Erm... I'm pretty sure you mean that you got sucked into maths from physics, but, of course, physics uses manifolds and differential geometry ALL the time, especially if you're going to study Chaos or anything having to do with relativity.