They actually had a specification for it on their website a couple years ago. But it was one of the messiest, most convoluted thing I've ever seen.
Then I gather you've never seen the.XLS (et al) specification. We used to have a joke about not going into it without taking a buddy to guard your back & pull you out if you started acting like you were understanding it.
Um, no, actually each crate wouldn't have half as much friction. You're thinking of weight. Now weight (i.e. the force of gravity pulling the crate against the ground) is going to have some effect on the force required to move the crate along the ground (one crate would be easier to push than two), but it's not the same thing as friction.
No, I stand by my original statement, backed by any good physics book and everyday experence. Thing about it--putting a paperweight on a paper holds it in place because it increases the force (weight) pressing the paper to the desk; pulling a loaded sled is harder than pulling an empty sled; you can tie two stick together, end to end, but only if you tie them tightly. All of these things and many more reflect the fact that friction is proportional to the force normal to the plane of contact.
And given this, it can't be proportional to the area of contact, as my first post shows. This isn't rocket science, just simple basic physics.
I believe the issue is thickness; at least, from basic physics I'd expect voltage to be linked to the thickness (and the difference in temp. between the two sides) and amps to be linked to area (and the degree of coupling).
Thus, it would be meaningfull to talk about any of these or any products (e.g., area x thickness --> volume, voltage x amps --> watts, etc.) and micron amps would be some sort of effectiveness metric (backed, presumably, by some assumptions about body temp, room temp, etc). If this interpretation is correct, for device rated at x-and-so micron amps, total power would be proportional to total area.
There's no reason to "dig". All of the information you need to calculate the magnitude of the effect is publicly available. How much energy does a cell phone put out? How much of this could (using worst case assumption) be absorbed by the brain (or testicles, or whatever you fear losing to the fearful technology demons)? What could this amount of energy do, and how does it compare to the background?
It isn't dificult if you have a half-way decent math background, just very tedious. And, as it turns out, pointless. Unless the cell phone companies are conspiring to change the laws of physics (which I strongly doubt), the fears over cell phone useage are nothing more than ludite humbug.
-- MarkusQ
P.S. I however agree with one point you made:
You can generally measure the degree of somebody's programming by the violence of their knee-jerk response when you point the fact out to them.
In the spirit of free-as-in-chaos, I have instituted my own private ranking system. You get +1 for funny on this, thought I admit it took me a minute to get it.
I disagree with the very premise of this thread: I, in fact, would not think that friction should be proportionate to the area of contact.
Think about it. By simple everyday experence we know that friction is proportionate to the force of contact (typically, the weight of the load). So if you have to drag two identical crates, which are currently stacked one atop the other, and want to reduce the friction you can remove the top crate, cutting the friction in half. Note that you haven't affected the area of contact at all.
Now suppose you decice to move both crates at the same time, but not stacked. Each crate will have half the friction of the original load, and thus the whole will have the same friction, even though we have doubled the area of contact.
This is in the same category as the "you'd think lead bricks should fall faster than iron bricks of the same size and shape" or "which weighs more, a pound of lead or a pound of feathers"?
You might assume that friction was proportional to the area of contact, but you wouldn't think it.
The Cell and PCS phone structure is a far superior system when it comes to bathing the populace in EM radiation.
The effects achieved by exposing people to close range low frequency CRT radiation, while slightly different, are more than made up for by the effects of the much higher frequency delivery system portable phones facilitate. Shorter exposure durations are required for the desired effects, and individuals who were left out of the 'computer revolution' are now included, not just through the popularity of hand set use, but also as a result of the proliferation of the microwave broadcast towers used throughout urbane areas.
Ask yourself what is achieved by this, (research is required), and who benefits. Hint: It has nothing to do with cancer.
Just curious, did you cut and paste this text from the ads for those tin-foil hats that block out the alien mind control beams?
In answer to your "ask who benefits" I only see three possible beneficiaries of this sort of babble: people who run call-in talk shows,
lawyers who want to stir up doubt till it's thick enough to sue someone with deep pockets, and paranoids who are going to be afraid of something and might as well be afraid of this.
Push on the debris with the laser light from ahead of its orbit. The satellite gains some orbital energy, the debris loses some. Eventually, the debris deorbits.
If the goal is to deorbit the debris, we can take the fact that it loses energy as given. However, depending on the relative orbits, it isn't clear that the laser platform will gain energy. If they are appoching each other head on, for example, they both lose energy. In most cases, I suspect the effect on the platform would be a mild course correction with little change in total energy. One strategy might be:
Rule 1) Don't shoot at targets that would reduce our orbital energy (eliminating 1/2 the potential targets).
Rule 2) Only shoot at half the remaining targets, chosen so that we consistantly precess our orbit, bringing previously ignored targets onto our active list.
Another thought is that we get the delta-V even if we don't hit the target, so we can always shoot at nothing (after confirming that there is in fact nothing there) to adjust our course.
(For that matter, I've never quite understood why they don't send up a big, thick Kevlar mat. A dragnet. Scoop a clear path 'round the geostationary orbit, and send the shit to the sun...)
You have to consider the volume in question. Imagine that there was an invisible pop can somewhere within a kilometer or so of the ground over your home country, floating exactly the way a brick doesn't. Your job is to scan the air with a net till you catch it. Even with a very large net, you could be out there for many years.
Now consider that the can is moving, so just because you didn't find it someplace yesterday doesn't mean it isn't there now.
Multiply in the fact that your country covers a very small fraction of the earth's surface (<<10%), and that the layer we are concerned about is many hundreds of kilometers thick--we aren't just concerned with things "in" the orbit we're trying to protect, but in anything that might cross that orbit...
Now consider that you don't know how many invisible pop cans you're after, and people keep sneaking up new invisible pop cans...I could go on, but I think you get the point.
A tobacco virus attacks tobacco plants, sure, but if I was examing how two similar tobacco viruses worked, I wouldn't refer to them as tobacco viruses, I'd refer to their particular classification
So, if there was only one Microsoft Worm you'd be willing to call attention to the fact that it only affects Microsoft boxes, but because there are lots of them we should obscure the fact by calling them by made up names like Alto-Muffy and PeachFuzz-37?
-- MarkusQ
+1 Veracity on the MQR standard
on
VIM 6.0 is Out
·
· Score: 4, Funny
How do you mean 'start a holy war'... vi vs emacs
stems from way back... it's the mother of all flamewars.
You're quite right. I don't know why you got modded down for this (Offtopic?); I suppose it's just another example of the old adage "Those that don't remember history are doomed to misuse mod points."
-- MarkusQ
+2 Funny on the MQR standard
on
VIM 6.0 is Out
·
· Score: 2
+2 funny on my private ranking system. You don't need it, but you deserve it. That was the funniest rant I've read in a long time.
Nature is a peer reviewed journal, and one of the more prestigious ones to boot.
-- dragons_flight
Damn, here I've been going under the misapprehension that nature is a big open place full of green things and other things that can poop on you. -- ENOENT
Sheesh! Do mod points destroy your sense of humour? This was clearly a joke! I can't give you karma, but I can give you my appreciation, which trades for karma about 3::4 on the junk bond market.
The pattern of where the bits are hidden has to be a constant because the reciever has to be able to find them to:)
The pattern does not have to be constant; it simply has to be derivable by the recipient. For example, we could agree that when I diddle the low-order bit of the blue component of a pixel, the red component of the same pixel gives the offset to the next pixel which contains data...etc.
We can get as complex as we like, provided we agree on the system. This is one of the things that makes it silly to even talk about "measuring steganography on the internet." It's also one of the case where "security through obscurity" pays off--or, to quote an old adage, people don't rob banks they can't find.
To take this even further, imagine a system like Blonde=0, Dark hair=1; Large breasts=0, Small breasts=1; Full frontal=0, Partial=1; etc. where the pictures are to be read in the normal reading order. This provides a 64 bit convolution key, which is used to combine all of the images from another site; the result is used to select letters from the postings on an unrelated newsgroup...
I defy anyone to prove that this sort of system is or isn't being used. And note that it need not use any standard encryption software.
I said that Americans "didn't seem to care much"; by this I meant exactly what I said, that what caring there was was neither as copious nor as evident as the outpouring we are seeing for the WTC disaster. I stand by that statement. The earthquake did not take over the media for days, it did not cause enormous disruption in people's daily life, it did not cause people to re-evaluate their sense of personal safety, and it did not evoke a proportionate delivery of aid.
In rebuttal you said (and I quote): "What are you talking about? Millions of dollars were sent over to India, along with rescue people, to help in the disaster."
Now, this would only serve as an effective rebuttal of my position if either A) we treat all big numbers as simply "big" or B) you were actually claiming that the response to the earthquake was proportionate to the response to the WTC--that is, roughly four times as large, since there were roughly four times as many victims.
Taking the more charitable interpretation of your intention, I did the math and found that, in fact, the billions spent on a disaster that killed thousands is far more that millions spent on a disaster that killed tens of thousands. This confirms my initial position.
You then twist my original statement (while falling to the old debaters trick of accusing me of twisting things in the same breath); you attempt to imply that I said that "no one cared" (and thus quantification is irrelevant) when in fact I said that "no one here seemed to care much."
I recall, for example, a murderer was caught,
but was later found innocent because the
glove didn't fit...
Yeah, let's look at the facts at *this* case please...
I'm sorry, I thought my intent would be clear from context. I wasn't attempting to offer anecdotal evidence; I was attempting to introduce reasonable doubt, by showing that there could plausibly be another explanation for the facts as we know them.
I was not attempting to argue that this alternative possibility was in fact true, merely that it existed.
Before we get too up in arms, is it possible that they both drew from a common source (app notes, published specs, etc.)? Code can look similar for many reasons. I recall, for example, a university "cheater detection" program that "caught" a large number of cheaters--in a course on code reuse--because they had used identical variable names, layout, etc. It was subsequently discovered that they had all noticed that the problem given was a minor variation on an example given in their textbook, and had used that as a starting point.
By analogy, if I give a gun to a criminal, some people would hold me partially accountable for what the criminal does with it, especially if I knew (or should have known) that this was a criminal. If I give a gun to a kid, I'm responsible for evaluating whether the kid's ready to learn about guns, and if so, to teach the kid about safety, etc.
Does the analogy extend to scientists?
The analogy does not hold. This is clear once you realize that science is a process of discovery, not of creation. A scientist is more like an explorer, discovering facts that were true long before they were discovered, facts that would eventually have been discovered by someone, facts that affect everyone, even the people who don't know them.
Newton should not be blamed for all the people who die from falling, just because he discovered the law of universal gravitation. Nor should he be blamed for ballistic missiles, which rely on his law for their operation.
A better analogy would be:
Should explorers who discover old mine fields or dangerous animals publish the fact? Or should they let others that follow blindly wander into the danger, unruffled but no safer in their ignorance.
...Poll Says Most Americans Favor Crypto Backdoors...
[NYT]...discussing how some of the "encryption should be free for everyone" attitudes are changing with the WTC attacks...
It doesn't matter what polls say, or how people's attitudes change; the fundamental issue is that crypto-backdoors, laws against strong crypto, etc. etc. are doomed to failure because they won't work.
This is not to say that such laws might not get passed, causing untold inconvenience to law-abiding citizens, chilling research, and compromising our national security by giving crackers a weak point to attack; all I'm saying is that such laws mathematically can't serve their purported purpose.
Assuming a population of 285 millions (U.S. Census Bureau [census.gov]), and an average life of 77 years (NCHS [cdc.gov]), we can work it out:
285.000.000 / (77*365) = 10140 deaths/day
That is the stupidest formula I have ever seen
No, the formula he gave is prefectly reasonable. If there are 285 million Americans alive at this moment, and we don't expect them (on average) to be alive 77 years from now, then they will have to die on one of the next 365*77 days (days per year times 77 years). That means on a typical day, 285 Million / (77*365) of them will die.
The slight dodge of saying we expect them all to die in the next 77 years on average doesn't significantly affect the outcome since we expect about as many people not-yet-born to die before they reach 77 as we expect extant people to live past 77.
This is a tech flame war so old, it predates the term "flame war." There have been a number of books written on the subject, and (perhaps typicaly of flame wars) both sides frequently make claims that are clearly false (e.g. QWERTY puts commonly used characters under strong fingers, and frequent pairs far apart; QWERTY was designed to slow typists down).
The truth isn't hard to see under the FUD: the QWERTY layout was designed to speed typists on the original machine by reducing the frequency of jams. It did this at some cost (of the most frequently used keys, ETAION, only one (A) is on the home row, and that under the left pinky, arguably the weakest finger). It was a reasonable tradeoff at the time but became a standard, with all the attendent entrenched opposition to change. This is where the FUD starts to come in. Dvorak et al overstated the advantages of their alternatives, and this gave the established manufacturers enough room to "debunk" their claims, launching hundred years of bickering.
What are you talking about? Millions of dollars were sent over to India, along with rescue people, to help in the disaster. It was all over the news. How can you say people here didn't care about it?
You're right, from this we can even quantify how much they care: the death of someone in India in an earthquake (from these numbers) causes about 1/10000 the amount of concern that the death of an American to terrorism does (based on dollars per casualty).
Of course, most of the current outpouring is going to help affected companies, which skews the numbers a little.
Also, you never did answer the comment about Nukes. What do you think we should do to stop terrorists from blowing up a nuke in the US?
I don't recall (or see) the question prior to your posting, but here is a sketch of an answer: for someone to commit an intentional act three things are required--Means, Motive, and Opportunity. I would suggest doing our flat out best to prevent anyone from having any of these with regard to nuking a city. I frankly don't care if the person that sets off the bomb is a "terrorist" or a "militia man" or a "disgruntled postal worker" or even a "democratically ellected leader" since I will be just as dead.
Slashdot Mirror
Then I gather you've never seen the .XLS (et al) specification. We used to have a joke about not going into it without taking a buddy to guard your back & pull you out if you started acting like you were understanding it.
-- MarkusQ
No, I stand by my original statement, backed by any good physics book and everyday experence. Thing about it--putting a paperweight on a paper holds it in place because it increases the force (weight) pressing the paper to the desk; pulling a loaded sled is harder than pulling an empty sled; you can tie two stick together, end to end, but only if you tie them tightly. All of these things and many more reflect the fact that friction is proportional to the force normal to the plane of contact.
And given this, it can't be proportional to the area of contact, as my first post shows. This isn't rocket science, just simple basic physics.
-- MarkusQ
-- MarkusQ
Cute.
And not, dispite what someone seems to think, offtopic at all.
--MarkusQ
Thus, it would be meaningfull to talk about any of these or any products (e.g., area x thickness --> volume, voltage x amps --> watts, etc.) and micron amps would be some sort of effectiveness metric (backed, presumably, by some assumptions about body temp, room temp, etc). If this interpretation is correct, for device rated at x-and-so micron amps, total power would be proportional to total area.
On the other hand, it might just be a typo.
-- MarkusQ
It isn't dificult if you have a half-way decent math background, just very tedious. And, as it turns out, pointless. Unless the cell phone companies are conspiring to change the laws of physics (which I strongly doubt), the fears over cell phone useage are nothing more than ludite humbug.
-- MarkusQ
P.S. I however agree with one point you made:
You can generally measure the degree of somebody's programming by the violence of their knee-jerk response when you point the fact out to them.
-- MarkusQ
Think about it. By simple everyday experence we know that friction is proportionate to the force of contact (typically, the weight of the load). So if you have to drag two identical crates, which are currently stacked one atop the other, and want to reduce the friction you can remove the top crate, cutting the friction in half. Note that you haven't affected the area of contact at all.
Now suppose you decice to move both crates at the same time, but not stacked. Each crate will have half the friction of the original load, and thus the whole will have the same friction, even though we have doubled the area of contact.
This is in the same category as the "you'd think lead bricks should fall faster than iron bricks of the same size and shape" or "which weighs more, a pound of lead or a pound of feathers"?
You might assume that friction was proportional to the area of contact, but you wouldn't think it.
-- MarkusQ
-- MarkusQ
The effects achieved by exposing people to close range low frequency CRT radiation, while slightly different, are more than made up for by the effects of the much higher frequency delivery system portable phones facilitate. Shorter exposure durations are required for the desired effects, and individuals who were left out of the 'computer revolution' are now included, not just through the popularity of hand set use, but also as a result of the proliferation of the microwave broadcast towers used throughout urbane areas.
Ask yourself what is achieved by this, (research is required), and who benefits. Hint: It has nothing to do with cancer.
Just curious, did you cut and paste this text from the ads for those tin-foil hats that block out the alien mind control beams?
In answer to your "ask who benefits" I only see three possible beneficiaries of this sort of babble: people who run call-in talk shows, lawyers who want to stir up doubt till it's thick enough to sue someone with deep pockets, and paranoids who are going to be afraid of something and might as well be afraid of this.
In short, bah humbug.
-- MarkusQ
Great idea. One quibble though:
Push on the debris with the laser light from ahead of its orbit. The satellite gains some orbital energy, the debris loses some. Eventually, the debris deorbits.
If the goal is to deorbit the debris, we can take the fact that it loses energy as given. However, depending on the relative orbits, it isn't clear that the laser platform will gain energy. If they are appoching each other head on, for example, they both lose energy. In most cases, I suspect the effect on the platform would be a mild course correction with little change in total energy. One strategy might be:
Rule 1) Don't shoot at targets that would reduce our orbital energy (eliminating 1/2 the potential targets).
Rule 2) Only shoot at half the remaining targets, chosen so that we consistantly precess our orbit, bringing previously ignored targets onto our active list.
Another thought is that we get the delta-V even if we don't hit the target, so we can always shoot at nothing (after confirming that there is in fact nothing there) to adjust our course.
-- MarkusQ
You have to consider the volume in question. Imagine that there was an invisible pop can somewhere within a kilometer or so of the ground over your home country, floating exactly the way a brick doesn't. Your job is to scan the air with a net till you catch it. Even with a very large net, you could be out there for many years.
Now consider that the can is moving, so just because you didn't find it someplace yesterday doesn't mean it isn't there now.
Multiply in the fact that your country covers a very small fraction of the earth's surface (<<10%), and that the layer we are concerned about is many hundreds of kilometers thick--we aren't just concerned with things "in" the orbit we're trying to protect, but in anything that might cross that orbit...
Now consider that you don't know how many invisible pop cans you're after, and people keep sneaking up new invisible pop cans...I could go on, but I think you get the point.
-- MarkusQ
So, if there was only one Microsoft Worm you'd be willing to call attention to the fact that it only affects Microsoft boxes, but because there are lots of them we should obscure the fact by calling them by made up names like Alto-Muffy and PeachFuzz-37?
-- MarkusQ
You're quite right. I don't know why you got modded down for this (Offtopic?); I suppose it's just another example of the old adage "Those that don't remember history are doomed to misuse mod points."
-- MarkusQ
Thank you!
--MarkusQ
- Nature is a peer reviewed journal, and one of the more prestigious ones to boot.
-- dragons_flightDamn, here I've been going under the misapprehension that nature is a big open place full of green things and other things that can poop on you. -- ENOENT
Sheesh! Do mod points destroy your sense of humour? This was clearly a joke! I can't give you karma, but I can give you my appreciation, which trades for karma about 3::4 on the junk bond market.
-- MarkusQ
The pattern of where the bits are hidden has to be a constant because the reciever has to be able to find them to :)
The pattern does not have to be constant; it simply has to be derivable by the recipient. For example, we could agree that when I diddle the low-order bit of the blue component of a pixel, the red component of the same pixel gives the offset to the next pixel which contains data...etc.
We can get as complex as we like, provided we agree on the system. This is one of the things that makes it silly to even talk about "measuring steganography on the internet." It's also one of the case where "security through obscurity" pays off--or, to quote an old adage, people don't rob banks they can't find.
To take this even further, imagine a system like Blonde=0, Dark hair=1; Large breasts=0, Small breasts=1; Full frontal=0, Partial=1; etc. where the pictures are to be read in the normal reading order. This provides a 64 bit convolution key, which is used to combine all of the images from another site; the result is used to select letters from the postings on an unrelated newsgroup...
I defy anyone to prove that this sort of system is or isn't being used. And note that it need not use any standard encryption software.
-- MarkusQ
In rebuttal you said (and I quote): "What are you talking about? Millions of dollars were sent over to India, along with rescue people, to help in the disaster."
Now, this would only serve as an effective rebuttal of my position if either A) we treat all big numbers as simply "big" or B) you were actually claiming that the response to the earthquake was proportionate to the response to the WTC--that is, roughly four times as large, since there were roughly four times as many victims.
Taking the more charitable interpretation of your intention, I did the math and found that, in fact, the billions spent on a disaster that killed thousands is far more that millions spent on a disaster that killed tens of thousands. This confirms my initial position.
You then twist my original statement (while falling to the old debaters trick of accusing me of twisting things in the same breath); you attempt to imply that I said that "no one cared" (and thus quantification is irrelevant) when in fact I said that "no one here seemed to care much."
-- MarkusQ
I recall, for example, a murderer was caught, but was later found innocent because the glove didn't fit...
Yeah, let's look at the facts at *this* case please...
I'm sorry, I thought my intent would be clear from context. I wasn't attempting to offer anecdotal evidence; I was attempting to introduce reasonable doubt, by showing that there could plausibly be another explanation for the facts as we know them.
I was not attempting to argue that this alternative possibility was in fact true, merely that it existed.
-- MarkusQ
-- MarkusQ
Does the analogy extend to scientists?
The analogy does not hold. This is clear once you realize that science is a process of discovery, not of creation. A scientist is more like an explorer, discovering facts that were true long before they were discovered, facts that would eventually have been discovered by someone, facts that affect everyone, even the people who don't know them.
Newton should not be blamed for all the people who die from falling, just because he discovered the law of universal gravitation. Nor should he be blamed for ballistic missiles, which rely on his law for their operation.
A better analogy would be:
Should explorers who discover old mine fields or dangerous animals publish the fact? Or should they let others that follow blindly wander into the danger, unruffled but no safer in their ignorance.
-- MarkusQ
[NYT]...discussing how some of the "encryption should be free for everyone" attitudes are changing with the WTC attacks...
It doesn't matter what polls say, or how people's attitudes change; the fundamental issue is that crypto-backdoors, laws against strong crypto, etc. etc. are doomed to failure because they won't work.
This is not to say that such laws might not get passed, causing untold inconvenience to law-abiding citizens, chilling research, and compromising our national security by giving crackers a weak point to attack; all I'm saying is that such laws mathematically can't serve their purported purpose.
That is the message that needs to get out.
-- MarkusQ
285.000.000 / (77*365) = 10140 deaths/day
That is the stupidest formula I have ever seen
No, the formula he gave is prefectly reasonable. If there are 285 million Americans alive at this moment, and we don't expect them (on average) to be alive 77 years from now, then they will have to die on one of the next 365*77 days (days per year times 77 years). That means on a typical day, 285 Million / (77*365) of them will die.
The slight dodge of saying we expect them all to die in the next 77 years on average doesn't significantly affect the outcome since we expect about as many people not-yet-born to die before they reach 77 as we expect extant people to live past 77.
--MarkusQ
The truth isn't hard to see under the FUD: the QWERTY layout was designed to speed typists on the original machine by reducing the frequency of jams. It did this at some cost (of the most frequently used keys, ETAION, only one (A) is on the home row, and that under the left pinky, arguably the weakest finger). It was a reasonable tradeoff at the time but became a standard, with all the attendent entrenched opposition to change. This is where the FUD starts to come in. Dvorak et al overstated the advantages of their alternatives, and this gave the established manufacturers enough room to "debunk" their claims, launching hundred years of bickering.
-- MarkusQ
You're right, from this we can even quantify how much they care: the death of someone in India in an earthquake (from these numbers) causes about 1/10000 the amount of concern that the death of an American to terrorism does (based on dollars per casualty).
Of course, most of the current outpouring is going to help affected companies, which skews the numbers a little.
Also, you never did answer the comment about Nukes. What do you think we should do to stop terrorists from blowing up a nuke in the US?
I don't recall (or see) the question prior to your posting, but here is a sketch of an answer: for someone to commit an intentional act three things are required--Means, Motive, and Opportunity. I would suggest doing our flat out best to prevent anyone from having any of these with regard to nuking a city. I frankly don't care if the person that sets off the bomb is a "terrorist" or a "militia man" or a "disgruntled postal worker" or even a "democratically ellected leader" since I will be just as dead.
--MarkusQ