in many countries people are more interested in protecting their own interests than their country's. (just look at jean cretien, ostensible prime minister of canada.) in mexico, the courts are easily bought, and more cheaply than the US congress and senate.
Now, yes, you can invent frames of reference which tend to ignore any acceleration you want. However, in any normal frame of reference, centripetal acceleration does exist, and centrifugal force is merely an experience (you feel your equal and opposite reaction to your centripetal acceleration, and notice that you are drifting away if the centripetal acceleration is lost).
yes, centrifugal force does not have the fundamental reality of a place in the simple and complete description of classical mechanics that newton et al. formulated. it is indeed a mathematical device to allow one to use the familiar language of force and acceleration to decribe mechanics as seen in a rotating frame of reference. and yes you can live in that rotating frame but still describe all motion by taking a view from outside and using pure newtonian mechanics, but that will not necessarily be worth the trouble. when you are in that rotating frame, being pressed against the car door, it is more convenient to think of that pressure as being due to centrifugal force. after all, it feels real enough. your flesh is being distorted in the area of contact. if the door isn't secure you may notice that you are drifing away at quite an alarming rate! (though no longer accelerated (till you hit the ground), and probably no longer concerned with the car's frame of reference:)
anyway, forces come in pairs. if the car door presses on you with centripetal force, what do you call the force with which you press upon the car door?
Sorry to be a physics geek here, but there's no such thing as "centrifugal" force, unless you're talking about the force caused by a centrifuge dropped from a height.
There IS "centripetal" force, that refers to the force on an object travelling in a circle, which pushes outward from the axis of said circle on an object while it's travelling about the radius.
centripetal force is a force acting toward the centre. in the stone on a string example, it is the force (tension in the string) pulling the stone toward the holder of the string, making it move in a circle. nothing is "travelling about the radius", and nothing is pushing outward from the axis. strings don't push!
centrifugal force is something you get in rotating frames of reference. one doesn't normally use such frames in physics because they are unecessarily complicated. but that is just a matter of calculational convenience; centrifugal forces are real enough in a rotating frame (it is called a fictitious force because it depends on the choice of frame, rather than being intrinsic. see this page). take a fast curve in a car and that fictitious force feels real enough, even if it isn't the simplest way to describe the situation mathematically.
yes, they do. fortunatly no one except the headline writer is proposing to use spark gaps. the story started by mentioning hertz and his sparkgap demos, and i guess the headline writer didn't read any farther than that.
poetry to the rescue
on
Coding Fair Use
·
· Score: 1, Offtopic
"Hey, how are we going to flog this tedious book about computers?"
"Simple - put something about terrorists in it."
9/11 can tie into anything. soon after the event, as i turned to the food section of my daily paper, i thought "at least they won't tie this into 9/11". but there it was: an article on comfort food and fear of terrorism!
Re:Y2K Problems
on
Byte Wars
·
· Score: 3, Interesting
I remember going to the Official Time Clock of the US Naval Observatory
i went there a few years ago and found the clocks didn't work. the html was so badly broken that it was amazing the browser didn't crash. i sent them a message about that, and they replied that the site was "browser dependent". in a way -- netscape tolerated the errors enough to put up some clocks; other browsers did not.
i just went back. the site is different but still broken. for example: <img SRC="/cgi-bin/nph-usnoclock.gif?zone=EST;ticks=11" ALT IMG SRC="/cgi-bin/gifclock.gif?zone=EST">
some of their img tags have alt text saying that you need netscape!
i don't understand how this site was made. there are html editors that make bad code, but that bad? but how could a human produce such nonsense by hand?
obviously not like talking to an eliza type program You'd be hard pressed to trick anyone that can read that they are talking to anything other than a computer script.
when weizenbaum made eliza available on his campus system, lots of people started "talking" to it. when he proposed to log the conversations for analysis there was a huge outcry. people were telling eliza their problems and secrets!
it's amazing how little plausibility such a thing really needs. adults acted as if they were fooled. kids might well really be fooled. and even if they know intellectually that they are talking to a computer, all the advertizer really needs is that the "conversation" have the persuasive power of a real one. emotionally, it may well have.
A pellet of uranium an inch long and half an inch in diameter produces almost as much energy as a ton of coal.
that's not a useful comparison. the coal comes out of the ground pretty much pure; the uranium does not. it takes a lot of ore and a lot of refining. compare the cost of mining and delivering that ton of coal with the cost of mining and refining the amount of ore that went into that uranium fuel pellet. (as for what the costs actually are, i have no idea.)
Solar --> Electical --> Decomposition of seawater --> Hydrogen. Whats so hard about it?
avaiability and efficiency. there isn't all that much solar power that hits the ground, and it's rather spread out. then you lose a lot on each link of that chain. that question is not enough. you must ask what it will cost in land, equipment, and maintenance. then compare with similar categories for extractin hydrogen. then you will know how to choose. of course, how YOU choose and how someone else chooses may be differnt, depending on, for example, the differing environmental effects.
sure, but any excess ends up in the ocean. it's not as if the ocean can get saturated, as it can with CO2. the amount of water in the atmosphere is determined by the balance between evaporation and precipitation. it would take one hell of a lot of hydrogen burning to add noticably to the rate of evaporation over all the oceans.
the unmentioned price actuall, the article did say "should be less expensive than current memory technology", but given the generally poor technical tone, i would guess that they meant "less than flash memory".
i'm hard pressed to guess who is responsible for filling that article with nonsense: clueless journalist, clueless editor, clueless "researcher", clueless marketeers... some or all of them should know that rebooting isn't only done because the machine was deliberatly powered down. some or all of them should know that simply having all memory intact isn't good enough if external environment has changed (eg network connections). some or all of them should know that disk-based versions of 'instant reboot' have been around for years, and don't always work. and what's this about faster multimedia downloads? what's memory got to do with it?
this whole thing reads like marketing bumpf. wishfull thinking on the marketeers' part, as usual.
I'd much rather get shot once from a room's distance than be stabbed, clubbed,...
my reply was to the notion that if guns were not available, then only criminals would have guns. my point was that if guns are not available, they are not available to anyone, criminal or otherwise.
the thing about guns is that they are easy, quick, and devastating. someone can pull out a gun and do you major damage before you can move. a powerful enough handgun can render you unconscious if it hits you at all, and your assailant can finish you off at leisure. a club or knife requires that they cross the room to get to you. this gives you a much better chance to defend yourself or escape.
the other thing about guns is that they are mostly used by family members in heated arguments, not by criminals in planned crimes. the second-most common incident is a homeowner shot with his own gun by a thief. in those situations it is irrelevant whether criminals have guns or not.
"The undersigned agrees to indemnify and hold harmless IEEE...
IANAL, but this sounds like the author is agreeing not to sue IEEE for actions arising out of publication, NOT that the author is agreeing to pay IEEE's expenses if someone sues the IEEE.
Slashdot Mirror
other countries like to protect their interests
in many countries people are more interested in protecting their own interests than their country's. (just look at jean cretien, ostensible prime minister of canada.) in mexico, the courts are easily bought, and more cheaply than the US congress and senate.
It's clear that what Microsoft is doing is securing markets outside of the first world nations by giving away much now and reaping the benefits later.
M$ has learned from the purveyors of tobacco and infant formula.
...foreign countries taking Microsoft to task now that the US DoJ has led the way.
i hope they do it with more backbone than the DoJ showed.
a Target credit card embedded with a computer chip, using a card reader that the chain will provide free of charge.
i wonder if this will provide some of the kind of unanticipated opportunities that the CueCat did.
Now, yes, you can invent frames of reference which tend to ignore any acceleration you want. However, in any normal frame of reference, centripetal acceleration does exist, and centrifugal force is merely an experience (you feel your equal and opposite reaction to your centripetal acceleration, and notice that you are drifting away if the centripetal acceleration is lost).
:)
yes, centrifugal force does not have the fundamental reality of a place in the simple and complete description of classical mechanics that newton et al. formulated. it is indeed a mathematical device to allow one to use the familiar language of force and acceleration to decribe mechanics as seen in a rotating frame of reference. and yes you can live in that rotating frame but still describe all motion by taking a view from outside and using pure newtonian mechanics, but that will not necessarily be worth the trouble. when you are in that rotating frame, being pressed against the car door, it is more convenient to think of that pressure as being due to centrifugal force. after all, it feels real enough. your flesh is being distorted in the area of contact. if the door isn't secure you may notice that you are drifing away at quite an alarming rate! (though no longer accelerated (till you hit the ground), and probably no longer concerned with the car's frame of reference
anyway, forces come in pairs. if the car door presses on you with centripetal force, what do you call the force with which you press upon the car door?
Sorry to be a physics geek here, but there's no such thing as "centrifugal" force, unless you're talking about the force caused by a centrifuge dropped from a height.
There IS "centripetal" force, that refers to the force on an object travelling in a circle, which pushes outward from the axis of said circle on an object while it's travelling about the radius.
centripetal force is a force acting toward the centre. in the stone on a string example, it is the force (tension in the string) pulling the stone toward the holder of the string, making it move in a circle. nothing is "travelling about the radius", and nothing is pushing outward from the axis. strings don't push!
centrifugal force is something you get in rotating frames of reference. one doesn't normally use such frames in physics because they are unecessarily complicated. but that is just a matter of calculational convenience; centrifugal forces are real enough in a rotating frame (it is called a fictitious force because it depends on the choice of frame, rather than being intrinsic. see this page). take a fast curve in a car and that fictitious force feels real enough, even if it isn't the simplest way to describe the situation mathematically.
Don't spark gap transmitters...
yes, they do. fortunatly no one except the headline writer is proposing to use spark gaps. the story started by mentioning hertz and his sparkgap demos, and i guess the headline writer didn't read any farther than that.
retaining ambiguity
write all laws and regulations in verse.
"Hey, how are we going to flog this tedious book about computers?"
"Simple - put something about terrorists in it."
9/11 can tie into anything. soon after the event, as i turned to the food section of my daily paper, i thought "at least they won't tie this into 9/11". but there it was: an article on comfort food and fear of terrorism!
I remember going to the Official Time Clock of the US Naval Observatory
" ALT IMG SRC="/cgi-bin/gifclock.gif?zone=EST">
i went there a few years ago and found the clocks didn't work. the html was so badly broken that it was amazing the browser didn't crash. i sent them a message about that, and they replied that the site was "browser dependent". in a way -- netscape tolerated the errors enough to put up some clocks; other browsers did not.
i just went back. the site is different but still broken. for example:
<img SRC="/cgi-bin/nph-usnoclock.gif?zone=EST;ticks=11
some of their img tags have alt text saying that you need netscape!
i don't understand how this site was made. there are html editors that make bad code, but that bad? but how could a human produce such nonsense by hand?
obviously not like talking to an eliza type program
You'd be hard pressed to trick anyone that can read that they are talking to anything other than a computer script.
when weizenbaum made eliza available on his campus system, lots of people started "talking" to it. when he proposed to log the conversations for analysis there was a huge outcry. people were telling eliza their problems and secrets!
it's amazing how little plausibility such a thing really needs. adults acted as if they were fooled. kids might well really be fooled. and even if they know intellectually that they are talking to a computer, all the advertizer really needs is that the "conversation" have the persuasive power of a real one. emotionally, it may well have.
It sucks, but it's what competition drives us towards.
only if we are sheep.
if we don't let them drive us, they will stop trying. but we do have to put in some effort.
What is the deal with Quebec (can't be language as everything in Canada is required to be bilingual)?
only quebec requires businesses to be totally bilingual. elsewhere, it's only government services, and good luck most places.
A pellet of uranium an inch long and half an inch in diameter produces almost as much energy as a ton of coal.
that's not a useful comparison. the coal comes out of the ground pretty much pure; the uranium does not. it takes a lot of ore and a lot of refining. compare the cost of mining and delivering that ton of coal with the cost of mining and refining the amount of ore that went into that uranium fuel pellet.
(as for what the costs actually are, i have no idea.)
Solar --> Electical --> Decomposition of seawater --> Hydrogen. Whats so hard about it?
avaiability and efficiency. there isn't all that much solar power that hits the ground, and it's rather spread out. then you lose a lot on each link of that chain.
that question is not enough. you must ask what it will cost in land, equipment, and maintenance. then compare with similar categories for extractin hydrogen. then you will know how to choose.
of course, how YOU choose and how someone else chooses may be differnt, depending on, for example, the differing environmental effects.
Water is a potent greenhouse gas
sure, but any excess ends up in the ocean. it's not as if the ocean can get saturated, as it can with CO2. the amount of water in the atmosphere is determined by the balance between evaporation and precipitation. it would take one hell of a lot of hydrogen burning to add noticably to the rate of evaporation over all the oceans.
Well, IAAL*, and indemnify generally means to assume liability for any valid claims, and for expenses associated with such claims.
ah, thank you. i had thought that 'indemnify' had a weaker meaning than that, something like "won't come after you".
from the article:
"It can be used in PCs, cell phones, networks -- anything that needs massive memory."
i know the japanese are big on fancy cell phones, but do they really need massive memory yet?
the unmentioned price
actuall, the article did say "should be less expensive than current memory technology", but given the generally poor technical tone, i would guess that they meant "less than flash memory".
i'm hard pressed to guess who is responsible for filling that article with nonsense: clueless journalist, clueless editor, clueless "researcher", clueless marketeers...
some or all of them should know that rebooting isn't only done because the machine was deliberatly powered down.
some or all of them should know that simply having all memory intact isn't good enough if external environment has changed (eg network connections).
some or all of them should know that disk-based versions of 'instant reboot' have been around for years, and don't always work.
and what's this about faster multimedia downloads? what's memory got to do with it?
this whole thing reads like marketing bumpf. wishfull thinking on the marketeers' part, as usual.
perhaps all offices should institute a staggered mandatory 15 minute inactivity period every couple of hours for each active computer.
the sysadmin of a server farm would never move again!
I'd much rather get shot once from a room's distance than be stabbed, clubbed, ...
my reply was to the notion that if guns were not available, then only criminals would have guns. my point was that if guns are not available, they are not available to anyone, criminal or otherwise.
the thing about guns is that they are easy, quick, and devastating. someone can pull out a gun and do you major damage before you can move. a powerful enough handgun can render you unconscious if it hits you at all, and your assailant can finish you off at leisure. a club or knife requires that they cross the room to get to you. this gives you a much better chance to defend yourself or escape.
the other thing about guns is that they are mostly used by family members in heated arguments, not by criminals in planned crimes. the second-most common incident is a homeowner shot with his own gun by a thief. in those situations it is irrelevant whether criminals have guns or not.
why not mark the button with 'D' for 'denounce'?
surely it is F for fink.
"The undersigned agrees to indemnify and hold harmless IEEE ...
IANAL, but this sounds like the author is agreeing not to sue IEEE for actions arising out of publication, NOT that the author is agreeing to pay IEEE's expenses if someone sues the IEEE.
Yes, everything will be much better when only the criminals have guns.
and where will the criminals get guns if they are no longer for sale? make them themselves? that's not nearly as easy as making heroine.