Rather than look outside the U.S with the usual language barriers that ensue, look instead to the middle 90% of the country.
What language barriers? There's a billion English speakers in India (and, quite frankly, their English tends to be a lot better than what I keep seeing from the flyover states). There's more English speakers in China than in the US.
And contrary to Kentucky, there are actually smart and motivated people in India and China, who's goal in life is a modest amount of luxury in return for hard work.
Could you explain to me where all of these tax dollars are in regards to "Illegal Aliens". By definition, they're not paying taxes.
This ludicrous retardation has already been told off by someone else.
If your concern is you imagined lack of tax-income from illegal aliens, then why do you refuse to let them pay taxes??? It is YOU retarded anti-immigration morons who decide that these people should not be allowed to pay taxes. If you imagine that there's millions of non-tax-paying people in this country, all you'd have to do is print millions of social security cards and send them to them and suddenly you'd have millions of taxpayers.
Declare all the "illegal alies" to be "legal aliens" and you have expanded the tax-base. Right there. Out of nothingness. No further effort needed. It's the best deal on the plnet: the US economy did not have to pay for these folks upbringing or education, but when they're fully-matured adults, willing to work, they come here. And all you have to do is hand them a TIN and they'll become happy, healthy contributors to the economy. But you mental retards deny them the right to pay taxes!! And then you whine that they're not paying taxes.
Does "republican" truly mean "mentally retarded moron" or does it only seem that way?
The article doesn't explain exactly where you have to stick the gel patch;).
Yeah, that's the dirty little secret: The patch is three feet long by two feet wide and 11 inches thick. It has to be applied topically directly on the penis. Studies show that it prevents fertility with almost complete efficiency...
does a vasectomy... eh... unload the gun, or do you just start shooting blanks.
Last time I checked (early nineties, but I don't see why that should've changed since then) there was the idea that you're still...uh... "primed for seven shot". After that you can carry a teaspoon of goo to the clinic to have them verify your infertility.
Actually, I take it back, the chances are significant that reversal procedures don't succed.
Depends -- technology hasn't exactly stood still. There's a variety of options out there these days, including things that are effectively clamps that are put onto the tubes (instead of cutting them) that can be removed fairly easily at some later day. Usually there's some additional (minor, outpatient) surgery needed to re-open your tubing as it tends to grow shut where it was clamped shut, but the success-rate of that stuff apears to be a lot higher than trying to re-attach hoses that were disconnected for many years.
It's been many years since I've read up that kind of thing, but at the time there were new options almost on an annual basis.
(Writing this as a guy whos "between 25 and 35" period started in the 90ies and who's slept with double-digit numbers of folks during that decade. Dunno what people's problem is. Maybe if you didn't try to have sex with ugly women who don't want to have sex with you but instead try to bed the cute and horny ones you'd be more successful? Just a suggestion...)
Is W3C so blind not to see what is so obvious? Are they so deaf not to hear the million developer's voices asking for only one thing? Stability.
CSS2 has been around for over eight years now. So where's the fully-compliant browser?
I'd say the W3C has been holding up their end of the "stability" bargain quite admirably. Maybe these "milion developers" shuld actually start thinking about delivering on their end of it?
use the lowest weight oil your manufacturer recommends.
This, of course, is nonsense. There's a reason that manufacturers often give a range and just because your particular situation makes one side of the range worthwhile doesn't mean that'll translate to someone else's situation.
The manufacturer of my motorbike (Suzuki) recommends 10W40. That's a recommendation for a bike that is driven all over the US: from Maine to Montana to Arizona to Florida. A recommendation for regions where temperatures drop below freezing in winter and can hit ninety in summer. Unfortunately I live in southern California, where the last recorded incident of freezing temperatures was 1949 and we don't turn on the A/C until it hits 100. It doesn't make sense for me to use something watery like 10W40 -- I use 20W50 and my twenty-eight year old bike seems to agree with me just fine.
Really: when there's a range of products somewhere, then there's usually a reason for the existence of that range and any advice based on anything less than research of the exact situation of the asker is going to be worth as much as a coin-flip.
What short-term or even mid-term payoff could there possibly be to being carbon nuetral?
Is it really so much of a strech to predict that environmental regulations are only going to get tighter in the future? That there's going to be Carbon allowances? That there's going to be EPA constraints on carbon imbalance?
Google is future-proofing itself at a time when they certainly have the resources to do so. That's just sound business policy.
Ten years down the road when y'all get your hefty carbon-surcharge on your electricity bill, Google (and everybody else that went solar in this decade) will shrug and say "told ya so".
Within the framework of a capitalist system, "value" is measured by putting a product onto a market and letting the various forces have a go at it. However many bucks you can make in the end is the "value" of the entity in question.
Would you be willing to buy "hell.com" if you knew for sure that something like it can be sold for a million dollars? Would you consider it valuable?
Mass is irrelevant when maintaining a constant angular momentum, all else (like coefficient of friction) equal. Once spinning, aerodynamics and friction are running the show.
For a given geometry (area, spin-speed) and coefficient of friction and all that, you will get a given frictional torque. Two flywheels of differing mass (and the same rpm) will have differing amounts of angular momentum. You are thus eating away on two different amounts of angular momentum with the same torque. Which means that you need different amounts of time to consume that stored angular momentum.
If the thinner disks can indeed be made smaller (because more can be stacked on top of each other) then this flywheel will carry even less angular momentum. That is: less rotational energy to put in when spinning up. It will also see less friction as it has less area exposed to the air. That is: less rotational energy dissipated while rotating at any given speed.
I'm not in the least convinced about the MTBF claims, resonant wobble in the thin disks, claims about cost of production, claims about speed and so forth - but that is costs less energy to keep a smaller object spinning (all else equal) really isn't rocket science.
this would be just as shock resistant as a Flash drive, but with faster seek time.
Of course the seek time of a flash drive is zero, since the term "seek" refers to the motion of a head (which is absent in a flash drive). So I'm wondering how they're going to improve on "zero".
(Yes, I know latency is meant. Just doing my part niggling over technical details...)
It's not he didn't know what he were doing was determined to be unlawful and punishable as a federal crime.
It's not? It sure is the first time that I have heard someone being prosecuted for providing the technological means to somone else to violate copyright law. For that's all a Bittorrent-tracker is. It is NOT an act of copying or distributing anything, merely a way for clients to get in contact with each other in order to copy something.
As far as I can tell, this verdict means we will haul librarians to jail if they put a photocopier into the library: providing others with the means to violate copyright.
Where exactly is the line here? Which section of the USC was actually violated here?
This thread is not about the impossibility of an energy-conserving first order method. It is SPECIFICALLY about the naive cartesian Euler method, which is what I presumed the OP implemented.
Sorry if you feel like I'm stepping on your toes here, but the thread is specifically NOT about cartesian anything. The GP was referring to Euler discretization of time and pronounced that this somehow poses a problem. Which is doesn't, if you pick proper coordinates.
The second paragraph in the comment you link to is false as it is written there. That's all there is to it. A newtonian model can be completely exact even if the time-steps are finite. As long as you choose proper circular coordinates.
You are stating that there is something wrong with taking the system as linear in time. And that the error introduced by that accumulates over time. But there is nothing wrong with that linearity assumption because expressed in the right coordinates the system is indeed linear in time.
Express the model in circular coordinates (relative to the center of gravity) and you can make you time-steps as discrete as you want without introducing an error, because your equations of motion will be
"r = const" and "phi = t * const"
and at that point you can compute r(t) from r(t-delta t) (and the same for phi) for finite (i.e. non-infinitesimal) "delta t".
Bizarre. mass element dm - pseudo-forces-integrating over dm - Euler-lagrange equations...
Nothing bizarre about it. It's called "physics".
This confirms a theory I have long had that advanced math, like other dangerous weapons, should not be put into the hands of children without at least a few semesters on how to think.
I.e. people like yourself.
I gave you all the required pointers. With them, you can go and see for yourself by yourself with your own eyes that a space elevator cannot exist. But you've never learned to think, so you merely keep regurgitating the same physically impossible science fiction. Like this:
Try the following thought experiment. Tie a kilogram weight on the end of a long string. Start swinging it around your head.
It is physically impossible to swing a mass around my head unless I rotate it fast enough. Do yourself and me and all the readers a favor and do not respond to the previous sentence until you have learned to think.
The correct thought experiment here is a flat, slippery table, the kilogram sliding frictionless on the table, you are in the center of the table (sticking out through a hole, say) and you're trying to orbit the mass around you on a rope. If you are going fast enough, this will obviously be possible. But if you're going very, very slowly, you're merely going to wind the rope around you, reeling the weight in towards you.
The earth rotates once per day. Which is too slow. As you could see for yourself if you were willing to do the math.
Once you start thinking, you realize that the total rotational kinetic energy of the system must exceed the gravitational potential for the apparent force on the object (in the rotational coordinate system) to be directed outward. No, that's not going to be revealed to you by some kind of magic, it requires that you learn to think.
To enhance the thought experiment, you are standing on a magic platform in no (micro) gravity space, swinging your string around. Can you rotate it around slowly? Yes.
No, you cannot. If you rotate slowly enough you simply become a spool upon which the tether winds itself until the mass has been reeled in.
Put it another way. Speed the earths rotation up. Faster and faster, until a geosynchronous orbit is about twenty feet off the ground (It'll drive the birds nuts, but hey, it's for science). Tie a rock on a string, hang on to the end of the string and toss your rock fifty feet straight up. It'll stay up there, I promise.
Of course. Which is what I have been telling you all along: if the rotational energy of the system is high enough, then a space elevator tied to a geosync station is possible. In the case of the Earth, it is not high enough. That is all there is to it.
Geo-synch is not really magic in terms of the system.
So why are you treating it as if it were magic? As if the invocation of "geosync" alone absolved you from the necessity to do your homework, compute all the forces and energies in the system and see for yourself what's going to happen?
Your unwillingness to examine the actual, real, true (capital R) Reality of the situation in favor of hand-waving and invocation of magic makes it quite clear where you're coming from.
I always thought that immortality could be used as a stealth weapon, albeit a slow one. Pretend there is a country you don't like but can't legally go to war with.
...so you elect a Republican president and bomb the hell outta them anyways. "legal, shmegal" be damned. Much cheaper than immortality drugs.
Re:lack of gravitational pull??
on
The Sun Had Sisters
·
· Score: 2, Informative
for even a simple two-body system using the inverse-square law, the orbiting object will spiral outward due to accumulated discretization error.
Yep, and it's easy to see why without even doing any math. Assuming the initial conditions are set up for a circular orbit, the body's initial velocity is at 90 degrees to the vector to the "sun". In the first timestep, the body will move only along this perpendicular direction,
You're both wrong, of course. The order of discretization has nothinig to do with this, the naive choice of coordinates does. It is easy to do a fine (first-order!) simulation if you choose appropriate coordinates: In the case of a circular orbit, for example, the phase-angle of the orbit is all you need - it is the only thing the Lagrangian depends on explicitly and only linearly. Pick phi and r as your coordinates and the very first line on your page will be "d/dt r=0".
In a more general case, energy or angular momentum are usually good coordinates to use, because the Lagrangian does not depend on them. And thus they are conserved simply by inspection of the equations. And thus the only way you could ever lose them is by making a programming mistake.
Slashdot Mirror
Rather than look outside the U.S with the usual language barriers that ensue, look instead to the middle 90% of the country.
What language barriers? There's a billion English speakers in India (and, quite frankly, their English tends to be a lot better than what I keep seeing from the flyover states). There's more English speakers in China than in the US.
And contrary to Kentucky, there are actually smart and motivated people in India and China, who's goal in life is a modest amount of luxury in return for hard work.
Could you explain to me where all of these tax dollars are in regards to "Illegal Aliens". By definition, they're not paying taxes.
This ludicrous retardation has already been told off by someone else.
If your concern is you imagined lack of tax-income from illegal aliens, then why do you refuse to let them pay taxes??? It is YOU retarded anti-immigration morons who decide that these people should not be allowed to pay taxes. If you imagine that there's millions of non-tax-paying people in this country, all you'd have to do is print millions of social security cards and send them to them and suddenly you'd have millions of taxpayers.
Declare all the "illegal alies" to be "legal aliens" and you have expanded the tax-base. Right there. Out of nothingness. No further effort needed. It's the best deal on the plnet: the US economy did not have to pay for these folks upbringing or education, but when they're fully-matured adults, willing to work, they come here. And all you have to do is hand them a TIN and they'll become happy, healthy contributors to the economy. But you mental retards deny them the right to pay taxes!! And then you whine that they're not paying taxes.
Does "republican" truly mean "mentally retarded moron" or does it only seem that way?
The article doesn't explain exactly where you have to stick the gel patch ;).
Yeah, that's the dirty little secret: The patch is three feet long by two feet wide and 11 inches thick. It has to be applied topically directly on the penis. Studies show that it prevents fertility with almost complete efficiency...
So what would this system do with something like KLentucky Fried (the movie), which contains a lof of spoofs of what this supposedly filters?
does a vasectomy ... eh ... unload the gun, or do you just start shooting blanks.
Last time I checked (early nineties, but I don't see why that should've changed since then) there was the idea that you're still ...uh... "primed for seven shot". After that you can carry a teaspoon of goo to the clinic to have them verify your infertility.
Actually, I take it back, the chances are significant that reversal procedures don't succed.
Depends -- technology hasn't exactly stood still. There's a variety of options out there these days, including things that are effectively clamps that are put onto the tubes (instead of cutting them) that can be removed fairly easily at some later day. Usually there's some additional (minor, outpatient) surgery needed to re-open your tubing as it tends to grow shut where it was clamped shut, but the success-rate of that stuff apears to be a lot higher than trying to re-attach hoses that were disconnected for many years.
It's been many years since I've read up that kind of thing, but at the time there were new options almost on an annual basis.
(Writing this as a guy whos "between 25 and 35" period started in the 90ies and who's slept with double-digit numbers of folks during that decade. Dunno what people's problem is. Maybe if you didn't try to have sex with ugly women who don't want to have sex with you but instead try to bed the cute and horny ones you'd be more successful? Just a suggestion...)
The rates they are offering are much lower than any other service I know of.
google: skype
What are those "friends" you speak of?
CSS2 has been around for over eight years now. So where's the fully-compliant browser?
I'd say the W3C has been holding up their end of the "stability" bargain quite admirably. Maybe these "milion developers" shuld actually start thinking about delivering on their end of it?
A lot of people claim that you can't trust the masses, which I don't really believe.
You mean you don't trust the masses on this?
use the lowest weight oil your manufacturer recommends.
This, of course, is nonsense. There's a reason that manufacturers often give a range and just because your particular situation makes one side of the range worthwhile doesn't mean that'll translate to someone else's situation.
The manufacturer of my motorbike (Suzuki) recommends 10W40. That's a recommendation for a bike that is driven all over the US: from Maine to Montana to Arizona to Florida. A recommendation for regions where temperatures drop below freezing in winter and can hit ninety in summer. Unfortunately I live in southern California, where the last recorded incident of freezing temperatures was 1949 and we don't turn on the A/C until it hits 100. It doesn't make sense for me to use something watery like 10W40 -- I use 20W50 and my twenty-eight year old bike seems to agree with me just fine.
Really: when there's a range of products somewhere, then there's usually a reason for the existence of that range and any advice based on anything less than research of the exact situation of the asker is going to be worth as much as a coin-flip.
I can tell what your parents did for a living by the content of your posts.
You can? Even six word posts?
What short-term or even mid-term payoff could there possibly be to being carbon nuetral?
Is it really so much of a strech to predict that environmental regulations are only going to get tighter in the future? That there's going to be Carbon allowances? That there's going to be EPA constraints on carbon imbalance?
Google is future-proofing itself at a time when they certainly have the resources to do so. That's just sound business policy.
Ten years down the road when y'all get your hefty carbon-surcharge on your electricity bill, Google (and everybody else that went solar in this decade) will shrug and say "told ya so".
Is it really worth anything (or much)?
Within the framework of a capitalist system, "value" is measured by putting a product onto a market and letting the various forces have a go at it. However many bucks you can make in the end is the "value" of the entity in question.
Would you be willing to buy "hell.com" if you knew for sure that something like it can be sold for a million dollars? Would you consider it valuable?
Mass is irrelevant when maintaining a constant angular momentum, all else (like coefficient of friction) equal. Once spinning, aerodynamics and friction are running the show.
For a given geometry (area, spin-speed) and coefficient of friction and all that, you will get a given frictional torque. Two flywheels of differing mass (and the same rpm) will have differing amounts of angular momentum. You are thus eating away on two different amounts of angular momentum with the same torque. Which means that you need different amounts of time to consume that stored angular momentum.
If the thinner disks can indeed be made smaller (because more can be stacked on top of each other) then this flywheel will carry even less angular momentum. That is: less rotational energy to put in when spinning up. It will also see less friction as it has less area exposed to the air. That is: less rotational energy dissipated while rotating at any given speed.
I'm not in the least convinced about the MTBF claims, resonant wobble in the thin disks, claims about cost of production, claims about speed and so forth - but that is costs less energy to keep a smaller object spinning (all else equal) really isn't rocket science.
tubes, duh, obvious, yes, noshit (tagging beta)
What can I possibly add to that?
just to have the e-mail address satan@hell.com
... but everybody knows that the real hell is a .mil domain...
this would be just as shock resistant as a Flash drive, but with faster seek time.
Of course the seek time of a flash drive is zero, since the term "seek" refers to the motion of a head (which is absent in a flash drive). So I'm wondering how they're going to improve on "zero".
(Yes, I know latency is meant. Just doing my part niggling over technical details...)
Given that the 6.x.x.x class-A address space is reserved for the Army Information Systems Center, you may be closer than you think...
It's not he didn't know what he were doing was determined to be unlawful and punishable as a federal crime.
It's not? It sure is the first time that I have heard someone being prosecuted for providing the technological means to somone else to violate copyright law. For that's all a Bittorrent-tracker is. It is NOT an act of copying or distributing anything, merely a way for clients to get in contact with each other in order to copy something.
As far as I can tell, this verdict means we will haul librarians to jail if they put a photocopier into the library: providing others with the means to violate copyright.
Where exactly is the line here? Which section of the USC was actually violated here?
This thread is not about the impossibility of an energy-conserving first order method. It is SPECIFICALLY about the naive cartesian Euler method, which is what I presumed the OP implemented.
Sorry if you feel like I'm stepping on your toes here, but the thread is specifically NOT about cartesian anything. The GP was referring to Euler discretization of time and pronounced that this somehow poses a problem. Which is doesn't, if you pick proper coordinates.
The second paragraph in the comment you link to is false as it is written there. That's all there is to it. A newtonian model can be completely exact even if the time-steps are finite. As long as you choose proper circular coordinates.
You are stating that there is something wrong with taking the system as linear in time. And that the error introduced by that accumulates over time. But there is nothing wrong with that linearity assumption because expressed in the right coordinates the system is indeed linear in time.
Express the model in circular coordinates (relative to the center of gravity) and you can make you time-steps as discrete as you want without introducing an error, because your equations of motion will be
"r = const" and "phi = t * const"
and at that point you can compute r(t) from r(t-delta t) (and the same for phi) for finite (i.e. non-infinitesimal) "delta t".
Nothing bizarre about it. It's called "physics".
I.e. people like yourself.
I gave you all the required pointers. With them, you can go and see for yourself by yourself with your own eyes that a space elevator cannot exist. But you've never learned to think, so you merely keep regurgitating the same physically impossible science fiction. Like this:
It is physically impossible to swing a mass around my head unless I rotate it fast enough. Do yourself and me and all the readers a favor and do not respond to the previous sentence until you have learned to think.
The correct thought experiment here is a flat, slippery table, the kilogram sliding frictionless on the table, you are in the center of the table (sticking out through a hole, say) and you're trying to orbit the mass around you on a rope. If you are going fast enough, this will obviously be possible. But if you're going very, very slowly, you're merely going to wind the rope around you, reeling the weight in towards you.
The earth rotates once per day. Which is too slow. As you could see for yourself if you were willing to do the math.
Once you start thinking, you realize that the total rotational kinetic energy of the system must exceed the gravitational potential for the apparent force on the object (in the rotational coordinate system) to be directed outward. No, that's not going to be revealed to you by some kind of magic, it requires that you learn to think.
No, you cannot. If you rotate slowly enough you simply become a spool upon which the tether winds itself until the mass has been reeled in.
Of course. Which is what I have been telling you all along: if the rotational energy of the system is high enough, then a space elevator tied to a geosync station is possible. In the case of the Earth, it is not high enough. That is all there is to it.
So why are you treating it as if it were magic? As if the invocation of "geosync" alone absolved you from the necessity to do your homework, compute all the forces and energies in the system and see for yourself what's going to happen?
Your unwillingness to examine the actual, real, true (capital R) Reality of the situation in favor of hand-waving and invocation of magic makes it quite clear where you're coming from.
I always thought that immortality could be used as a stealth weapon, albeit a slow one. Pretend there is a country you don't like but can't legally go to war with.
...so you elect a Republican president and bomb the hell outta them anyways. "legal, shmegal" be damned. Much cheaper than immortality drugs.
You're both wrong, of course. The order of discretization has nothinig to do with this, the naive choice of coordinates does. It is easy to do a fine (first-order!) simulation if you choose appropriate coordinates: In the case of a circular orbit, for example, the phase-angle of the orbit is all you need - it is the only thing the Lagrangian depends on explicitly and only linearly. Pick phi and r as your coordinates and the very first line on your page will be "d/dt r=0".
In a more general case, energy or angular momentum are usually good coordinates to use, because the Lagrangian does not depend on them. And thus they are conserved simply by inspection of the equations. And thus the only way you could ever lose them is by making a programming mistake.
...ohhh - +5 funny. I'm sure he's never heard that joke before.