Solar Sails *can* tack.
on
Solar Sails
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· Score: 2
> Although facinating to consider, it seems that a solar sail would be of limited use for a two way trip. A solar sail powered spacecraft can't tack against the 'wind' like a sail boat on the ocean is able to do.
Actually it can, sort of, since the sun's gravity acts in the opposite direction to the solar wind and your ship is going to be in orbit about the sun, by angling the sails appropriately you can move to a closer orbit, as well as a more distant one.
http://www.ugcs.caltech.edu/~diedrich/solarsails /i ntro/tacking.html
If you are using an interstellar solar sails, possibly read "destination star" for "sun" at the far end - alternatively see
http://www.forwardunlimited.com/pdf/tp069.pdf "Roundtrip Interstellar Travel using Laser Pushed Lightsails" (yes, you can use an Earth based laser for the return journey, and you don't have to tack into it). --
> Your third condition is that it is possible to destroy it. How does, oh, land, fit that requirement? Sure, you could nuke it, but for most of the 5,000 years of civilization, land was permanent.
I believe ploughing in salt was the traditional way of destroying land's agricultural value, which, for most of the 5,000 years, was all that counted.
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Re:Remember that other DeCSS?
on
The DeCSS Haiku
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· Score: 1
They state under penalty of perjury "We have received information that... ". If they've received misinformation, but genuinely believe it to be accurate, is that enough for them to not be committing perjury?
> The easy answer is "Do it like we did it. Take several hundred years of negotiations, invention, and saving"
Also "Take over even less developed places as colonies, developing large empires, or expand into large uncharted wilderness, moving native peoples out of the way or conquering them, and finding new resources. Compete with other nations at the same level of development, without having to worry about competition or interference from contries already vastly more developed".
The timescale isn't the only problem with that as an easy answer.
I used to have (possibly still have somewhere) an old book that described how to use an (off-the-shelf) X-ray tube with a fluoroscope you can make yourself - basically a thin layer of crystals that glow when hit by X-rays. So you look directly towards the X-ray tube, put e.g. your hand in the way, then the fluoroscope in front of your hand, and you can see the bones in your hand. It needs a much larger dose of X-rays than exposing a film, but that wasn't considered a problem at the time.
http://www.uihealthcare.com/PatientsVisitors/Med Mu seum/CollectingFromPast/Devices/Devices.html
shows a couple of fluoroscopes, and says the coating was "calcium tungstate which fluoresced more brightly than the traditional coating of barium platinocyanide". Neither of those sounds familiar, but I think it was something Health and Safety regulations would make it hard to get hold of for the home experimenter these days.
One day I might get around to building the Whimshurst machine though.
(http://www.netspace.net.au/~tphefley/ has some instructions that looks very similar, and may even be from the same book ("The Boy Electrician"). --
> > at least 4 people will post [...] 'strings' on the windoze ftp client, it says it's bsd!!". And I'll say, "You do know that an ftp client isn't a tcp/ip stack?"
> C:\WINNT\system32>strings ftp.exe | grep -i copy
> your grassblade starship won't have enough power to send a signal back to earth to report its findings.
But if nanotechnology gets beyond being a pipedream, that needn't be a problem. Your grassblade starship lands, builds a few self-replicating exploratory/survey craft, then switches to building transmitter builder builders so when the survey is finished it can transmit the results back.
This also assumes any inhabitants of the planet don't object to self-replicating nanobots reshaping a chunk of it into a huge antenna and power station, and that your spaceship drive scales in such a way that a small spaceship can get anywhere in the first place anyway. --
I've had (non-computer) role-playing characters in love with characters played by someone I had no romantic attachment to at all. I've had role-playing characters of different sex and/or sexuality than myself. (I've had other characters guess the characters' real sex/sexuality when disguised/hidden.) And it was all fun.
But in none of those cases did any of the sexual or romantic elements get played in any detail - they were background, rather than the focus of the game. "X and Y flirt for a bit", rather than X's and Y's players playing through a flirtation.
There have also been games where real life relationships and game relationships did cross over to some extent without problems. On the other hand I've seen one in-game relationship get nasty enough that the GM basically gave up - there was no way these characters were going to work together, no matter how much circumstances threw them together. The players in question were in a relationship at the time, later split up, then got back together, then split up again, but stayed friends; the characters were likely to kill each other. (The characters in question didn't have a sexual relationship, but sex was an important part of the background - she was an ex-courtesan who didn't like men, but expected to be able to use sex to manipulate them, and was sometimes near suicidally depressed and/or reckless; and he was gay (but not openly so), and resented having been nearly killed because of her recklessness.)
> There is no end point in lifetime relationships
When you're lying on your deathbed looking back on your life, or it's flashing before your eyes after a truck hits you, or whatever, that's the endpoint. If you're thinking "that was pretty worthwhile on the whole", you've won. If you're thinking "at last this whole shitty existence is over" you've lost.
--
Re:This is exactly what the NSA wants you to think
on
RSA Cracked - Not
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· Score: 1
> The general method for triple-encryption of any block cipher is to use two keys, A and B
No. The general method is to use three keys. Using ABA is a (commonly used) special case of that.
Someone's borrowed my copy of Schneier, so I can't give a page reference in that right now, but yhe bottom of page 272 of HAC mentions both two and three key triple encryption (and EEE as well as EDE). See also RSA Labs Crypto FAQ
Now, the issue of whether to call this a single 112-bit key (AB) or a 168-bit key (ABA) with only 112 bits of entropy.
Read the reference I posted. There's more to it than repeating one of the keys.
--
> Anyone else besides me find it strange that priests show up in news stories as being gay, pedophiles, or both?
Not really. "Priest follows vows" isn't a news story, whether it's vows of celibacy or marriage (depending on what the religion allows), so you only hear about the exceptional ones. Probably some of them went into the priesthood because they thought it would help them avoid temptation, but failed; others went into it to intending to abuse a position of trust. It's sad, but I don't think it says anything much about religion.
However, when an organised religion systematically tries to ignore or cover up problem priests, then that does say something bad about that organised religion.
> How can the religious right not see the hypocracy in espousing brotherly love while hating gays?
Because that's what hypocrisy *is*. (Ok, being pedantic it doesn't mean they can't see it, it means they can see it and pretend not to, but the effect is the same). --
> OTOH, put a railgun in a submarine. It could be about the same length as the sub, of the order 100 meters,
An SF story whose name I can't remember right now (possibly Radix by A.A. Attanasio) had one on an airship. Now a Cargolifter 160 is supposed to be about 260m long with a payload of 160 tonnes.
I thought gauss guns were coil guns, not rail guns (no current flowing though the projectile). I found a few references that support this
(e.g. http://www.powerlabs.org/coilgun.htm) but some of them also seem to be talking about a completely different type of "railgun" (charged projectile accelerated by static electric field).
--
Re:This is exactly what the NSA wants you to think
on
RSA Cracked - Not
·
· Score: 1
> Triple-DES does give you the full 112 bits of your key, since triple-encryption manages to avoid that problem.
No, triple encryption has the same problem, which is why it only gives you 112 bits from a 168 bit key. (Though you can use a 168 bit key with 112 bits of entropy - http://khan.postech.ac.kr/crypto/joc/11n3p209.pdf) --
Essentially, you're saying "The government never covers anything up, because I never see any evidence of it!" Which...uh...kinda misses the point, right?:)
We do see some things that are embarrassing to the government. We haven't seen evidence of failed coverups. We have seen government spokesmen desperately trying to persuade us that stuff isn't really that embarrassing and we should ignore it and concentrate on "the real issues", while opposition spokesmen try and persuade us that the embarrassing issues are really really important because they show us the fundamental incompetence or rottenness of the government.
So either there aren't any coverups, or coverups are only used for really important stuff, and they work, and the opposition is in on it - which probably limits it to cases where the government can tell news editors "this is a matter of national security" and be believed. --
And not even Microsoft would be stupid enough to have two verification keys, one of which wasn't used normally, but was used if the first one failed, so it could be replaced by an attacker to get their code accepted without stopping code signed with the first key running.
Well actually, Microsoft were that stupid, but I think even they won't be stupid enough to do it twice.
Heck, they could even use a modified LGPL that forbids making the code GPL if they're really paranoid about it getting "infected" by the GPL.
That would make it unusable unless the whole kernel was LGPL. If they are going to do that, they might as well use a proprietary "source available but only for educational use" licence.
--
If the watermark isn't audible, lossy compression schemes which are designed to throw away as much information as possible without changing the sound will be trying to discard the watermark. In an extreme case, someone can play the sound through the best hi-fi they have, record it on the best mikes they have, and end up with something very close to the original, with no watermark.
On the other hand if the watermark is audible, people will be saying "This sucks, I can hear the watermark" (and even if it's only theoretically audible, the sort of music reviewers who can hear what colour felt tip was used on a CD rim and which way up the speaker cable was stored in the shop will be saying "This sucks, I can hear the watermark" just to show how good their hearing is). --
I still have a standing offer: will anyone have an architect without a degree design a house they would then live in?
A random stranger? No. Someone whose past work I've seen and liked; quite possibly. I am planning to live in a house designed by someone without a degree in architecture (and quite likely no degree at all). Does that count? The house is about 350 years old.
I don't know how long architecture degrees have existed, but the Architecture department at Cambridge was only established in 1912, so the designer of the house I live in at the moment (at least the Georgian and Victorian bits of it) probably didn't have an architecture degree either.
I'd really like to see a pointer to the relevent international copyright laws. If you are right, the implications for DeCSS/MPAA/DCMA, as well as on Microsoft EULAs, could much more important than someone providing a proprietry add-on to Linux which they have promised to GPL in afew months anyway.
Paper junk mail might be annoying, but there are opt-out lists, and the mailers do normally respect them, sometimes because there are laws saying they have to, but also because they have to pay to send the mail out, and want to do anything they can to improve their rate of return. (If you've asked to be taken off a mailing list and an incompetent company has ignored you, then fine, mail them inoffensive junk back reply paid until they get the message).
email spammers are completely different - they aren't paying to send the stuff, so they couldn't care less how many addresses that aren't interested get used, so long as a few recipients are interested. I think half the time the company selling the product has been conned by a spam "marketing" company who get paid anyway so they don't even care if _nobody_ is interested, so long as they can invoice for sending some huge number of adverts.
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Re:We need more writers like Julian Assange
on
Underground Surfaces
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· Score: 1
Why is it that it is only the women and their apologists that complain about this? When was the last time that you heard a man complain when somebody said that he should not stay at home with the children and cook and clean? Do men whine and say "I can if I want?" No. They accept it. A little less whining and a little bit more productive output would do this world a hell of a lot of good.
Some years ago, I worked for a small UK company, owned by a US company. Then the US company were bought by Prime, who tried to introduce new contracts.
Among other things the new contracts had a non-competition clause. The competition was defined as anyone making computer hardware or software of any kind. We objected and pointed out this was almost certainly an attept illegal restraint of trade under UK law, and the new management agreed - "Don't worry, we don't really mean that bit of the contract". "So you won't mind deleting it?" we said. "No, we need it there just in case".
Similarly with the anti-trust clause that said that any meeting or conversation, of any sort, work related or not, with anyone who worked in the computer industry, had to have written minutes. Those people with spouses working in the industry found that one particularly objectionable.
Eventually well over half the workforce returned the new contract letter saying "this is unacceptable for the following list of reasons", and they were forced to change it.
The manager whose initial response was "nice try, now let's see the real terms and conditions" eventually won his unfair dismissal case.
When I left some months later, about half the names on the old phone list in the machine room had already been crossed out, people were using desktop backgrounds of scanned job adverts, and one department had a "will the last person to resign please turn off the lights" sign.
They had recruited new people, but the company didn't last much longer (and Prime's minicomputer business didn't either). --
It's been quite a while since I last saw an issue of Playboy in its entirety. It was at about age 13 [...]
* Interviews (with many interesting people) [...]
I'm not claiming that these things don't exist, just that they didn't leave a lasting impression on me.
It's hardly surprising a 13 year old boy seeing his first Playboy is going to find the pictures make more of a lasting impression than the articles. But the articles, interviews, etc. are enough for Playboy to bother publishing a Braille edition. --
Slashdot Mirror
> Although facinating to consider, it seems that a solar sail would be of limited use for a two way trip. A solar sail powered spacecraft can't tack against the 'wind' like a sail boat on the ocean is able to do.
s /i ntro/tacking.html
Actually it can, sort of, since the sun's gravity acts in the opposite direction to the solar wind and your ship is going to be in orbit about the sun, by angling the sails appropriately you can move to a closer orbit, as well as a more distant one.
http://www.ugcs.caltech.edu/~diedrich/solarsail
If you are using an interstellar solar sails, possibly read "destination star" for "sun" at the far end - alternatively see
http://www.forwardunlimited.com/pdf/tp069.pdf "Roundtrip Interstellar Travel using Laser Pushed Lightsails" (yes, you can use an Earth based laser for the return journey, and you don't have to tack into it).
--
> Your third condition is that it is possible to destroy it. How does, oh, land, fit that requirement? Sure, you could nuke it, but for most of the 5,000 years of civilization, land was permanent.
I believe ploughing in salt was the traditional way of destroying land's agricultural value, which, for most of the 5,000 years, was all that counted.
--
They state under penalty of perjury "We have received information that ... ". If they've received misinformation, but genuinely believe it to be accurate, is that enough for them to not be committing perjury?
--
> The easy answer is "Do it like we did it. Take several hundred years of negotiations, invention, and saving"
Also "Take over even less developed places as colonies, developing large empires, or expand into large uncharted wilderness, moving native peoples out of the way or conquering them, and finding new resources. Compete with other nations at the same level of development, without having to worry about competition or interference from contries already vastly more developed".
The timescale isn't the only problem with that as an easy answer.
--
I used to have (possibly still have somewhere) an old book that described how to use an (off-the-shelf) X-ray tube with a fluoroscope you can make yourself - basically a thin layer of crystals that glow when hit by X-rays. So you look directly towards the X-ray tube, put e.g. your hand in the way, then the fluoroscope in front of your hand, and you can see the bones in your hand. It needs a much larger dose of X-rays than exposing a film, but that wasn't considered a problem at the time.
d Mu seum/CollectingFromPast/Devices/Devices.html
http://www.uihealthcare.com/PatientsVisitors/Me
shows a couple of fluoroscopes, and says the coating was "calcium tungstate which fluoresced more brightly than the traditional coating of barium platinocyanide". Neither of those sounds familiar, but I think it was something Health and Safety regulations would make it hard to get hold of for the home experimenter these days.
One day I might get around to building the Whimshurst machine though.
(http://www.netspace.net.au/~tphefley/ has some instructions that looks very similar, and may even be from the same book ("The Boy Electrician").
--
> > at least 4 people will post [...] 'strings' on the windoze ftp client, it says it's bsd!!". And I'll say, "You do know that an ftp client isn't a tcp/ip stack?"
> C:\WINNT\system32>strings ftp.exe | grep -i copy
One down, three to go.
--
> your grassblade starship won't have enough power to send a signal back to earth to report its findings.
But if nanotechnology gets beyond being a pipedream, that needn't be a problem. Your grassblade starship lands, builds a few self-replicating exploratory/survey craft, then switches to building transmitter builder builders so when the survey is finished it can transmit the results back.
This also assumes any inhabitants of the planet don't object to self-replicating nanobots reshaping a chunk of it into a huge antenna and power station, and that your spaceship drive scales in such a way that a small spaceship can get anywhere in the first place anyway.
--
I've had (non-computer) role-playing characters in love with characters played by someone I had no romantic attachment to at all. I've had role-playing characters of different sex and/or sexuality than myself. (I've had other characters guess the characters' real sex/sexuality when disguised/hidden.) And it was all fun.
But in none of those cases did any of the sexual or romantic elements get played in any detail - they were background, rather than the focus of the game. "X and Y flirt for a bit", rather than X's and Y's players playing through a flirtation.
There have also been games where real life relationships and game relationships did cross over to some extent without problems. On the other hand I've seen one in-game relationship get nasty enough that the GM basically gave up - there was no way these characters were going to work together, no matter how much circumstances threw them together. The players in question were in a relationship at the time, later split up, then got back together, then split up again, but stayed friends; the characters were likely to kill each other. (The characters in question didn't have a sexual relationship, but sex was an important part of the background - she was an ex-courtesan who didn't like men, but expected to be able to use sex to manipulate them, and was sometimes near suicidally depressed and/or reckless; and he was gay (but not openly so), and resented having been nearly killed because of her recklessness.)
--
> There is no end point in lifetime relationships
When you're lying on your deathbed looking back on your life, or it's flashing before your eyes after a truck hits you, or whatever, that's the endpoint. If you're thinking "that was pretty worthwhile on the whole", you've won. If you're thinking "at last this whole shitty existence is over" you've lost.
--
No. The general method is to use three keys. Using ABA is a (commonly used) special case of that.
Someone's borrowed my copy of Schneier, so I can't give a page reference in that right now, but yhe bottom of page 272 of HAC mentions both two and three key triple encryption (and EEE as well as EDE). See also RSA Labs Crypto FAQ
Now, the issue of whether to call this a single 112-bit key (AB) or a 168-bit key (ABA) with only 112 bits of entropy.
Read the reference I posted. There's more to it than repeating one of the keys.
--
> Anyone else besides me find it strange that priests show up in news stories as being gay, pedophiles, or both?
Not really. "Priest follows vows" isn't a news story, whether it's vows of celibacy or marriage (depending on what the religion allows), so you only hear about the exceptional ones. Probably some of them went into the priesthood because they thought it would help them avoid temptation, but failed; others went into it to intending to abuse a position of trust. It's sad, but I don't think it says anything much about religion.
However, when an organised religion systematically tries to ignore or cover up problem priests, then that does say something bad about that organised religion.
> How can the religious right not see the hypocracy in espousing brotherly love while hating gays?
Because that's what hypocrisy *is*. (Ok, being pedantic it doesn't mean they can't see it, it means they can see it and pretend not to, but the effect is the same).
--
> OTOH, put a railgun in a submarine. It could be about the same length as the sub, of the order 100 meters,
An SF story whose name I can't remember right now (possibly Radix by A.A. Attanasio) had one on an airship. Now a Cargolifter 160 is supposed to be about 260m long with a payload of 160 tonnes.
--
I thought gauss guns were coil guns, not rail guns (no current flowing though the projectile). I found a few references that support this
(e.g. http://www.powerlabs.org/coilgun.htm) but some of them also seem to be talking about a completely different type of "railgun" (charged projectile accelerated by static electric field).
--
> Triple-DES does give you the full 112 bits of your key, since triple-encryption manages to avoid that problem.
)
No, triple encryption has the same problem, which is why it only gives you 112 bits from a 168 bit key. (Though you can use a 168 bit key with 112 bits of entropy - http://khan.postech.ac.kr/crypto/joc/11n3p209.pdf
--
Essentially, you're saying "The government never covers anything up, because I never see any evidence of it!" Which...uh...kinda misses the point, right? :)
We do see some things that are embarrassing to the government. We haven't seen evidence of failed coverups. We have seen government spokesmen desperately trying to persuade us that stuff isn't really that embarrassing and we should ignore it and concentrate on "the real issues", while opposition spokesmen try and persuade us that the embarrassing issues are really really important because they show us the fundamental incompetence or rottenness of the government.
So either there aren't any coverups, or coverups are only used for really important stuff, and they work, and the opposition is in on it - which probably limits it to cases where the government can tell news editors "this is a matter of national security" and be believed.
--
And not even Microsoft would be stupid enough to have two verification keys, one of which wasn't used normally, but was used if the first one failed, so it could be replaced by an attacker to get their code accepted without stopping code signed with the first key running. Well actually, Microsoft were that stupid, but I think even they won't be stupid enough to do it twice.
See e.g. here or here.
--
Heck, they could even use a modified LGPL that forbids making the code GPL if they're really paranoid about it getting "infected" by the GPL.
That would make it unusable unless the whole kernel was LGPL. If they are going to do that, they might as well use a proprietary "source available but only for educational use" licence.
--
On the other hand if the watermark is audible, people will be saying "This sucks, I can hear the watermark" (and even if it's only theoretically audible, the sort of music reviewers who can hear what colour felt tip was used on a CD rim and which way up the speaker cable was stored in the shop will be saying "This sucks, I can hear the watermark" just to show how good their hearing is).
--
A random stranger? No. Someone whose past work I've seen and liked; quite possibly. I am planning to live in a house designed by someone without a degree in architecture (and quite likely no degree at all). Does that count? The house is about 350 years old.
I don't know how long architecture degrees have existed, but the Architecture department at Cambridge was only established in 1912, so the designer of the house I live in at the moment (at least the Georgian and Victorian bits of it) probably didn't have an architecture degree either.
Incidentally, the Cambridge Architecture department has a fairly cool paper on using Quake for architectural design.
--
I'd really like to see a pointer to the relevent international copyright laws. If you are right, the implications for DeCSS/MPAA/DCMA, as well as on Microsoft EULAs, could much more important than someone providing a proprietry add-on to Linux which they have promised to GPL in afew months anyway.
--
Paper junk mail might be annoying, but there are opt-out lists, and the mailers do normally respect them, sometimes because there are laws saying they have to, but also because they have to pay to send the mail out, and want to do anything they can to improve their rate of return. (If you've asked to be taken off a mailing list and an incompetent company has ignored you, then fine, mail them inoffensive junk back reply paid until they get the message).
email spammers are completely different - they aren't paying to send the stuff, so they couldn't care less how many addresses that aren't interested get used, so long as a few recipients are interested. I think half the time the company selling the product has been conned by a spam "marketing" company who get paid anyway so they don't even care if _nobody_ is interested, so long as they can invoice for sending some huge number of adverts.
--
--
Some years ago, I worked for a small UK company, owned by a US company. Then the US company were bought by Prime, who tried to introduce new contracts.
Among other things the new contracts had a non-competition clause. The competition was defined as anyone making computer hardware or software of any kind. We objected and pointed out this was almost certainly an attept illegal restraint of trade under UK law, and the new management agreed - "Don't worry, we don't really mean that bit of the contract". "So you won't mind deleting it?" we said. "No, we need it there just in case".
Similarly with the anti-trust clause that said that any meeting or conversation, of any sort, work related or not, with anyone who worked in the computer industry, had to have written minutes. Those people with spouses working in the industry found that one particularly objectionable.
Eventually well over half the workforce returned the new contract letter saying "this is unacceptable for the following list of reasons", and they were forced to change it.
The manager whose initial response was "nice try, now let's see the real terms and conditions" eventually won his unfair dismissal case.
When I left some months later, about half the names on the old phone list in the machine room had already been crossed out, people were using desktop backgrounds of scanned job adverts, and one department had a "will the last person to resign please turn off the lights" sign.
They had recruited new people, but the company didn't last much longer (and Prime's minicomputer business didn't either).
--
The thorn/eth confusion is in the sig of the post he was replying to - what makes you think he didn't get the joke?
--
It's been quite a while since I last saw an issue of Playboy in its entirety. It was at about age 13 [...]
I'm not claiming that these things don't exist, just that they didn't leave a lasting impression on me.It's hardly surprising a 13 year old boy seeing his first Playboy is going to find the pictures make more of a lasting impression than the articles. But the articles, interviews, etc. are enough for Playboy to bother publishing a Braille edition.
--