It's not like I don't understand your point of view, or haven't been trained in basic mechanics and physics. It's just that I have thought this out pretty fully.
First of all, let me say that you are totally correct when you say that a fan blowing air from the stern of a boat into a sail would not be an effective way to move the boat forward. I still believe that the boat could be made to go forward, but I don't want to argue about it.
It is also true, as you say, that the best bet would be to remove the sail and aim the fan backward. This is how hovercraft and swamp boats are propelled.
But let me also say that you are making a mistake when you ignore the air stream analysis. This is an aeorodynamics problem, and the easiest way to analyze it is to think about how the whole system effects the flow of air. If the net effect is to direct a stream of air molecules backwards, the boat WILL move forward, no matter how much you may want this to not be true. You can safely ignore all of the mechanical forces except the ones arising from the air molecules hitting the various fan blade and boat surfaces, and the hydrodynamic forces exerted on the hull by the water.
The easieset example to visualize is a fan blowing air athwartships (sideways) into a sail which would be angled so that it redirects the air stream aft (backwards). Now, you may argue (correctly) that there is some net sideways force created by the fan. Fine. The immersed foil (keel or centerboard) on the boat will prevent the boat from moving sideways with any kind of speed. But because the sail directs the air stream aft, you must admit that there will be a partial forward force on the boat. So, the boat will go forward.
I NEVER claimed that this was an efficient way to propel a boat. One poster did suggest that it might have a limited application to RC sailboats. This seems to make sense to me. It wouldn't be all that hard to add a small fan to a boat, and it might get you out of trouble if you find your boat adrift in very light winds.
It would work just about as well as you sitting in the boat and pushing on the sail.
This is not true.
For example, a ducted fan can propel a boat in any direction, regardless of where the air input is. The key is where you aim the ducting. Think of the sail as an elaborate duct.
Another way to think of it is to just imagine which way the air molecules end up going. This is sort of the mechanics approach to aerodynamics. If they get pulled in from all different directions (as with a fan) and hurled at a sail, where they bounce off or are otherwise re-directed and go backwards, the boat will go forwards. It would probably work best if the fan was beside the sail and blowing athwartships rather than behind it blowing forward, as most people seem to instinctively imagine.
I'm not trolling or being stupid. A fan-powered sailboat could very well work. The sail would act in much the same way as a thrust director on an airplane.
Note: I'm not saying that it MAKES SENSE to build a fan powered sailboat, just that it would go forward if it were designed correctly.
As long as you aren't using passwords that are straight out of the dictionary (this is like 3rd [sic] grade people) you should be fine even with something like this being available.
Well, not in a dictionary, not trendy slang, not an obvious transform or abbreviation of what's in a dictionary or trendy slang, longer than 8 characters, and include both upper and lower case as well as some punctuation.
A passphrase is indeed a good idea. You can also use a long password generated from the first letter from each word of a passphrase, provided that the passphrase is not something someone else would think of (e.g., a quote from a movie or book). If you do use the first letter technique, the phrase has to be very long. Maybe 15 words or so.
It's typical Microsoft vaporware. They announce an upgrade to put people off of the competition. Or at least that's what they used to do when they had competition.
If you want, and if you don't have a gmail account yet, post your email (Rot13'd or whatever) and I'll invite you to join gmail. I have something like 3 invitations left.
I'm not sure if I understand what you are saying. Which means maybe I didn't explain my idea very well.
I was envisioning a control system which could measure following distance and speed, and take over control of the brakes and throttle to maintain a very close following distance. This would, in effect, create a raft of tightly packed cars moving almost as one. It seems to me that this would increase the traffic density dramatically.
Maybe the simpler way to look at it (which I think is your point) is that collision avoidance technology in cars could provide increased density OR increased safety or some combination of the two, simply because the system always pays attention and has very short reaction times.
I'm too lazy to do any calculations, but I'm sure you could get down to less than 1 carlength even at 70+ MPH.
There would normally be no danger of these cars crashing into each other. But if an anomaly occurred, for example if a car travelling in a direction opposite to the raft crossed the center line and hit the lead car, several cars in the front of the raft might not be able to stop fast enough, even when braking to the point of impending lockup.
There is also the problem of how you get in and out of the raft safely.
Actually, the development I'm waiting for is the "raft-up" concept. The idea is that you would approach the car in front of you, hit a button that says "raft-up" and your car would then take over throttle and brakes to tailgate the car in front of you and use a control system to maintain distance. This could safely allow MUCH higher traffic density on freeways. I envision the driver still steering the car.
Realistically, no system like this will ever be fielded in the US. They'll work on it until it is totally idiot-proof and THEN it will appear in full glory.
It could potentially create a rational market for electricity. I think you identified one of the most immediate benefits when you mentioned the resistance to brown- and blackouts.
That is, presumably, as a brownout becomes imminent, the price goes up. This would provide a way for intelligent agents to shut down less essential systems as the price climbs.
In the future, there might be a negotiation process where supply is offered by multiple producers and individual buildings and plants would try to find the cheapest supplier to run from. This could allow real de-regulation of the market. It seems a bit far-fetched, but I think it is a cool idea nonetheless, and would allow people to really set their own tradeoffs between cost and comfort. This could lead to far more effective conservation than the stupid advertising campaigns we have now.
I am well aware that public key crypto is usually used only to encrypt symmetric cipher keys.
My question still stands. How does the key exchange work? If you use public key cryptography, how do you get the public key for the node you are negotiating with? If you just accept the key the node offers, then you could actually be negotiating with a man in the middle.
The SSL example doesn't really apply, because web browsers have a trust mechanism where they can verify public keys because they are signed by root authorities.
But in the wireless scenario, you have to negotiate a key before you even bring the link up, so you might have a problem. Then again, maybe not. Maybe the card stores some root authorities on board, or maybe the OS can get involved and check a signature on the proferred public key.
If they use diffie-hellman, they can be sure that no one is evesdropping, but there is still the man in the middle problem. It's a basic fact of cryptography that you have to have out-of-band communication prior to setting up a secure link over a public channel.
You can't just say oh, it uses AES. AES is a symmetric cipher, which implies that there is a shared session key.
How do the nodes generate and exchange a shared session key? Or do you have to enter an AES key manually before you even hook up? That would certainly lock down the node!
It would be nice if someone posted a link explaining at a medium level how it actually works. I don't want to just go read a draft of the standard, but I wouldn't mind reading a few of the important details.
possesive masculine = his
possesive feminine = hers
possesive no gender= its
simple.
Well, the confusing part is that when dealing with nouns, the apostrophe indicates possesion, but with pronouns the apostrophe isn't allowed in the possesive.
For example, in the title _Bill and Ted's Excellent Adventure_ (it should really be Bill's and Ted's Excellent Adventure, come to think of it), the "'s" makes Ted into a possesive.
Anyway, a lot of people screw up when it comes to "it's" and "its" so it must be confusing.;-)
It takes me back to wasting hours in the various UC Santa Cruz computer labs.
Heh. I remember people waiting in login queues to get onto UCSCB to play tetris. And there was an addict flag, IIRC, which would cause the game to log you off when it terminated.
I never got that into it, for some reason. Too busy "talk"-ing and "finger"-ing people, maybe.
Did you ever play mtrek? I remember the chalkboard slogans: "Mtrek is better than sex." And people would have raucous, epic battles. Sometimes large groups of people would be together in the same computer room, and the other players wouldn't necessarily know they were collaborating with each other.
I can't stand driving video games because I have a lot of trouble driving with a joystick. I'm not a big video game player in the first place, and that may be part of my problem.
However, I am an excellent driver in real life, and very comfortable behind the wheel.
I consider the wheel to be the ultimate user interface for a car, so even if I do buy a drive-by-wire car some day, I want a steering wheel to control it.
Am I just being old-fashioned? Does anyone have any first hand experience or links to serious examples of successful driving of cars by joystick?
It's fine, in this context, to require sexually explicit material to be labelled as such. But what about the opposite problem, where spammers label their spam as sexually explicit and then it turns out to just be a garden-variety multi-level marketing scam?
I mean, I would imagine that lots of people would check out explicit email once and a while hoping for a thrill, but not if it most of the purportedly explicit material is bogus.
The FCC should fine people who promise explicit material and don't deliver, too. Otherwise they might as well require the label to say "Unsolicited Junk Email".
MM --
Re:Reminds me of a poem
on
A Worm's Worm
·
· Score: 1
The article was specifically about the Strauss farm. They are a 100% organic and humane dairy farm. Their cows are all range fed. So the question stands.
In general I do agree with your cynicism about happy California Cows, however.;-)
Well, yeah, but the land cattle graze on is typically not arable. That is, you couldn't grow soybeans there if you wanted to.
The cattle graze it anyway.
I don't know for sure what proto-humans ate, but it wasn't grain. Grain production is only 10,000 years old or something like that.
If you just want to eat a healthy diet, try to stay away from refined grains like white rice and white flour. Sugar, regardless of whether it's sucrose, fructose, dextrose or some other sugar is not good for you in large quantities, particularly if you are overweight.
Since there is very little nutrition in processed grain foods, if you mostly eat pasta, rice, and white bread, you are eating a very poor diet, nutritionally speaking.
So whether you eat meat or not, make sure you eat plenty of green vegetables like spinach, chard, broccoli, or whatever turns you on. Do this every day. Edible seaweeds are good, too.
I know plenty of vegetarians who don't eat enough vegetables!
MM --
Reminds me of a poem
on
A Worm's Worm
·
· Score: 2, Funny
This reminds me of a poem I heard when I was a kid. I'm not sure who the original author is.
Every flea has a flea on his back to bite him. And on that flea another flea so ad infinitum.
Despite the growing success of the Open Source movement, most of the general public continues to feel that Open Source software is inaccessible to them. This paper discusses five fundamental problems with the current Open Source software development trend, explores why these issues are holding the movement back,[emphasis added] and offers solutions that might help overcome these problems.
The systemic, fundamental flaw with her analysis is that there is no united "open source" goal from which to be held back!
The assumption that all free and open source developers share the principal goal of supplanting or competing directly with more traditional software is just wrong.
For some projects, it may be true, but clearly not for others. Do the authors of ghostview want to supplant acrobat reader? I don't think so. Do the authors of the Gimp want to compete directly with photoshop? Perhaps.
Do Star Office and Open Office developers want to erode Microsoft's share of the office-suite world? You bet.
Do the mingw people want to compete with visual C++ (or whatever Microsoft's latest c++ compiler is called)? I don't think so.
In general, do you think GNU people want to compete with anybody? I don't. I think they just want to be free to create the kind of software they like.
It seems to me that there are a huge variety of goals out there, and in many cases, competing with commercial software is not one of them. In other cases it is. But in my opinion only newbies and idealists believe that free software should try to or will eventually take over the world and put closed software out of business.
What free sofware does is put pressure on commercial software. For example, I'm sure one of the reasons that Microsoft fixed the TCP/IP stack in its newer OS's is because the Linux and BSD stacks are so good. (In fact, I've heard people say that Microsoft just lifted the stack from some BSD variant. I don't know if that is true.) Microsoft also took a lot of heat for stability, once again due to the stability of various Unix-like OS's running on the same hardware. This has forced Microsoft to improve. Finally, now, Microsoft is taking tons of heat on security. We'll see how they react. (In my opinion, this already makes Linux and the BSD's a complete success. They forced Microsoft to compete!)
And of course, Linux is sort of like the blob. Microsoft tries to fight it off on some narrow front, but it just expands around that area and pushes in somewhere else. Whether it's servers, PDA's, the embedded market, or 64-bit systems, or gaming consoles, Linux is there, making life difficult for Microsoft, not out of malice, but just because it is what it is.
Slashdot Mirror
It's not like I don't understand your point of view, or haven't been trained in basic mechanics and physics. It's just that I have thought this out pretty fully.
First of all, let me say that you are totally correct when you say that a fan blowing air from the stern of a boat into a sail would not be an effective way to move the boat forward. I still believe that the boat could be made to go forward, but I don't want to argue about it.
It is also true, as you say, that the best bet would be to remove the sail and aim the fan backward. This is how hovercraft and swamp boats are propelled.
But let me also say that you are making a mistake when you ignore the air stream analysis. This is an aeorodynamics problem, and the easiest way to analyze it is to think about how the whole system effects the flow of air. If the net effect is to direct a stream of air molecules backwards, the boat WILL move forward, no matter how much you may want this to not be true. You can safely ignore all of the mechanical forces except the ones arising from the air molecules hitting the various fan blade and boat surfaces, and the hydrodynamic forces exerted on the hull by the water.
The easieset example to visualize is a fan blowing air athwartships (sideways) into a sail which would be angled so that it redirects the air stream aft (backwards). Now, you may argue (correctly) that there is some net sideways force created by the fan. Fine. The immersed foil (keel or centerboard) on the boat will prevent the boat from moving sideways with any kind of speed. But because the sail directs the air stream aft, you must admit that there will be a partial forward force on the boat. So, the boat will go forward.
I NEVER claimed that this was an efficient way to propel a boat. One poster did suggest that it might have a limited application to RC sailboats. This seems to make sense to me. It wouldn't be all that hard to add a small fan to a boat, and it might get you out of trouble if you find your boat adrift in very light winds.
MM
--
This is not true.
For example, a ducted fan can propel a boat in any direction, regardless of where the air input is. The key is where you aim the ducting. Think of the sail as an elaborate duct.
Another way to think of it is to just imagine which way the air molecules end up going. This is sort of the mechanics approach to aerodynamics. If they get pulled in from all different directions (as with a fan) and hurled at a sail, where they bounce off or are otherwise re-directed and go backwards, the boat will go forwards. It would probably work best if the fan was beside the sail and blowing athwartships rather than behind it blowing forward, as most people seem to instinctively imagine.
MM
Well. You saw it here first. ;-)
MM
--
I'm not trolling or being stupid. A fan-powered sailboat could very well work. The sail would act in much the same way as a thrust director on an airplane.
Note: I'm not saying that it MAKES SENSE to build a fan powered sailboat, just that it would go forward if it were designed correctly.
MM
--
Well, not in a dictionary, not trendy slang, not an obvious transform or abbreviation of what's in a dictionary or trendy slang, longer than 8 characters, and include both upper and lower case as well as some punctuation.
A passphrase is indeed a good idea. You can also use a long password generated from the first letter from each word of a passphrase, provided that the passphrase is not something someone else would think of (e.g., a quote from a movie or book). If you do use the first letter technique, the phrase has to be very long. Maybe 15 words or so.
MM
--
It's typical Microsoft vaporware. They announce an upgrade to put people off of the competition. Or at least that's what they used to do when they had competition.
If you want, and if you don't have a gmail account yet, post your email (Rot13'd or whatever) and I'll invite you to join gmail. I have something like 3 invitations left.
MM
--
I'm not sure if I understand what you are saying. Which means maybe I didn't explain my idea very well.
I was envisioning a control system which could measure following distance and speed, and take over control of the brakes and throttle to maintain a very close following distance. This would, in effect, create a raft of tightly packed cars moving almost as one. It seems to me that this would increase the traffic density dramatically.
Maybe the simpler way to look at it (which I think is your point) is that collision avoidance technology in cars could provide increased density OR increased safety or some combination of the two, simply because the system always pays attention and has very short reaction times.
I'm too lazy to do any calculations, but I'm sure you could get down to less than 1 carlength even at 70+ MPH.
There would normally be no danger of these cars crashing into each other. But if an anomaly occurred, for example if a car travelling in a direction opposite to the raft crossed the center line and hit the lead car, several cars in the front of the raft might not be able to stop fast enough, even when braking to the point of impending lockup.
There is also the problem of how you get in and out of the raft safely.
MM
--
Actually, the development I'm waiting for is the "raft-up" concept. The idea is that you would approach the car in front of you, hit a button that says "raft-up" and your car would then take over throttle and brakes to tailgate the car in front of you and use a control system to maintain distance. This could safely allow MUCH higher traffic density on freeways. I envision the driver still steering the car.
Realistically, no system like this will ever be fielded in the US. They'll work on it until it is totally idiot-proof and THEN it will appear in full glory.
MM
--
It could potentially create a rational market for electricity. I think you identified one of the most immediate benefits when you mentioned the resistance to brown- and blackouts.
That is, presumably, as a brownout becomes imminent, the price goes up. This would provide a way for intelligent agents to shut down less essential systems as the price climbs.
In the future, there might be a negotiation process where supply is offered by multiple producers and individual buildings and plants would try to find the cheapest supplier to run from. This could allow real de-regulation of the market. It seems a bit far-fetched, but I think it is a cool idea nonetheless, and would allow people to really set their own tradeoffs between cost and comfort. This could lead to far more effective conservation than the stupid advertising campaigns we have now.
MM
--
I am well aware that public key crypto is usually used only to encrypt symmetric cipher keys.
My question still stands. How does the key exchange work? If you use public key cryptography, how do you get the public key for the node you are negotiating with? If you just accept the key the node offers, then you could actually be negotiating with a man in the middle.
The SSL example doesn't really apply, because web browsers have a trust mechanism where they can verify public keys because they are signed by root authorities.
But in the wireless scenario, you have to negotiate a key before you even bring the link up, so you might have a problem. Then again, maybe not. Maybe the card stores some root authorities on board, or maybe the OS can get involved and check a signature on the proferred public key.
If they use diffie-hellman, they can be sure that no one is evesdropping, but there is still the man in the middle problem. It's a basic fact of cryptography that you have to have out-of-band communication prior to setting up a secure link over a public channel.
MM
--
You can't just say oh, it uses AES. AES is a symmetric cipher, which implies that there is a shared session key.
How do the nodes generate and exchange a shared session key? Or do you have to enter an AES key manually before you even hook up? That would certainly lock down the node!
It would be nice if someone posted a link explaining at a medium level how it actually works. I don't want to just go read a draft of the standard, but I wouldn't mind reading a few of the important details.
MM
--
Who modded the parent to flaimbait? Off topic, maybe.
Whatever.
Personally, I thought it was funny.
MM
--
Well, the confusing part is that when dealing with nouns, the apostrophe indicates possesion, but with pronouns the apostrophe isn't allowed in the possesive.
For example, in the title _Bill and Ted's Excellent Adventure_ (it should really be Bill's and Ted's Excellent Adventure, come to think of it), the "'s" makes Ted into a possesive.
Anyway, a lot of people screw up when it comes to "it's" and "its" so it must be confusing. ;-)
MM
--
You should play morse code training materials.
<morse code> di-dah
<Eisenhower era voice> "A"
di-dah "A"
di-dah "A"
dah-di-di-di "B"
dah-di-di-di "B"
dah-di-di-di "B"
Etc.
MM
--
Heh. I remember people waiting in login queues to get onto UCSCB to play tetris. And there was an addict flag, IIRC, which would cause the game to log you off when it terminated.
I never got that into it, for some reason. Too busy "talk"-ing and "finger"-ing people, maybe.
Did you ever play mtrek? I remember the chalkboard slogans: "Mtrek is better than sex." And people would have raucous, epic battles. Sometimes large groups of people would be together in the same computer room, and the other players wouldn't necessarily know they were collaborating with each other.
Thanks for reminding me about all that stuff.
MM
--
"It's" ALWAYS means "it is." To convey possesion, use "its."
This may not be a sensible or logical rule, but it is well-documented, nonetheless.
MM
--
I can't stand driving video games because I have a lot of trouble driving with a joystick. I'm not a big video game player in the first place, and that may be part of my problem.
However, I am an excellent driver in real life, and very comfortable behind the wheel.
I consider the wheel to be the ultimate user interface for a car, so even if I do buy a drive-by-wire car some day, I want a steering wheel to control it.
Am I just being old-fashioned? Does anyone have any first hand experience or links to serious examples of successful driving of cars by joystick?
MM
--
It's fine, in this context, to require sexually explicit material to be labelled as such. But what about the opposite problem, where spammers label their spam as sexually explicit and then it turns out to just be a garden-variety multi-level marketing scam?
I mean, I would imagine that lots of people would check out explicit email once and a while hoping for a thrill, but not if it most of the purportedly explicit material is bogus.
The FCC should fine people who promise explicit material and don't deliver, too. Otherwise they might as well require the label to say "Unsolicited Junk Email".
MM
--
Ah, makes sense.
Thanks.
MM
--
The article was specifically about the Strauss farm. They are a 100% organic and humane dairy farm. Their cows are all range fed. So the question stands.
;-)
In general I do agree with your cynicism about happy California Cows, however.
MM
--
Well, yeah, but the land cattle graze on is typically not arable. That is, you couldn't grow soybeans there if you wanted to.
The cattle graze it anyway.
I don't know for sure what proto-humans ate, but it wasn't grain. Grain production is only 10,000 years old or something like that.
If you just want to eat a healthy diet, try to stay away from refined grains like white rice and white flour. Sugar, regardless of whether it's sucrose, fructose, dextrose or some other sugar is not good for you in large quantities, particularly if you are overweight.
Since there is very little nutrition in processed grain foods, if you mostly eat pasta, rice, and white bread, you are eating a very poor diet, nutritionally speaking.
So whether you eat meat or not, make sure you eat plenty of green vegetables like spinach, chard, broccoli, or whatever turns you on. Do this every day. Edible seaweeds are good, too.
I know plenty of vegetarians who don't eat enough vegetables!
MM
--
This reminds me of a poem I heard when I was a kid. I'm not sure who the original author is.
Every flea has a flea
on his back to bite him.
And on that flea another flea
so ad infinitum.
MM
--
From the article:
The systemic, fundamental flaw with her analysis is that there is no united "open source" goal from which to be held back!
The assumption that all free and open source developers share the principal goal of supplanting or competing directly with more traditional software is just wrong.
For some projects, it may be true, but clearly not for others. Do the authors of ghostview want to supplant acrobat reader? I don't think so. Do the authors of the Gimp want to compete directly with photoshop? Perhaps.
Do Star Office and Open Office developers want to erode Microsoft's share of the office-suite world? You bet.
Do the mingw people want to compete with visual C++ (or whatever Microsoft's latest c++ compiler is called)? I don't think so.
In general, do you think GNU people want to compete with anybody? I don't. I think they just want to be free to create the kind of software they like.
It seems to me that there are a huge variety of goals out there, and in many cases, competing with commercial software is not one of them. In other cases it is. But in my opinion only newbies and idealists believe that free software should try to or will eventually take over the world and put closed software out of business.
What free sofware does is put pressure on commercial software. For example, I'm sure one of the reasons that Microsoft fixed the TCP/IP stack in its newer OS's is because the Linux and BSD stacks are so good. (In fact, I've heard people say that Microsoft just lifted the stack from some BSD variant. I don't know if that is true.) Microsoft also took a lot of heat for stability, once again due to the stability of various Unix-like OS's running on the same hardware. This has forced Microsoft to improve. Finally, now, Microsoft is taking tons of heat on security. We'll see how they react. (In my opinion, this already makes Linux and the BSD's a complete success. They forced Microsoft to compete!)
And of course, Linux is sort of like the blob. Microsoft tries to fight it off on some narrow front, but it just expands around that area and pushes in somewhere else. Whether it's servers, PDA's, the embedded market, or 64-bit systems, or gaming consoles, Linux is there, making life difficult for Microsoft, not out of malice, but just because it is what it is.
Anyway, just my $0.02.
MM
--
Well, Microsoft isn't the best example since they are a monopoly.
Many of us don't have a choice but to buy at least some microsoft products. Certainly at work I don't have any choice but to use them.
MM
--
I'm glad you don't have any more mod points. ;-)
Stallman is not talking about "free" as in "free of charge," but free of "Intellectual Property" restrictions.
This concept of freedom does apply somewhat to computer hardware, but not at all to electrical power utilities.
The computing hardware situation isn't too bad right now, but it could get worse with trusted computing and DRM, but it remains to be seen.
MM
--