The Samba folks don't publicize it, but they have found a number of buffer overflows in the stacks of every single OS out there. (They patched the ones they found in Linux.:-) A truly nasty critter would be set up to transmit itself using those overflows.
If done right you would get a worm or virus that can transmit from computer to computer without any manual intervention. There has to date been exactly one such on the internet. The Morris worm. It went out of its way to be nice, and it still shut down the Internet through sheer speed of reproduction.
You see getting a human in the loop slows things down. If you want to be truly nasty, automate it from start to finish. Then the first people will hear about it is when their networks go down.
For people who are serious about using encryption, the question is not whether in the future they will be able to use a method of encryption that can beat the methods of decryption then available, it is how long their secrets, transmitted today, will remain secret.
Some forms of encryption are good for discouraging casual novices. Some take a little time and are fine for short-lived secrets. Some will cause the NSA to blink. Some will last for a good while.
But the standard public-key encryption mechanism in use today will not survive the potential of quantum computers. So, for instance, digitally signed documents have a lifetime of a few decades before the signatures can be forged.
This is fine for credit card purchases. It may not be fine for some kinds of legal contracts.
The "funny symbols" define a miniature grammar. Learn that grammar and it gives you guidelines about how to think about hashes etc. (Guidelines such as what you should name them.) Next use strict to stop pointing your gun footwards. Warnings exist for a reason. Turn them on as well. Finally avoid default variables except where they are necessary.
Now follow basic sane programming guidelines and Perl is perfectly readable.
It gets a lot better when you start using it like it was meant to be used. For instance the language is a list-oriented language for a reason. There are a lot of constructs that are syntactic sugar. Use them wisely. Note that map() and grep() give you all of the power of a pipeline without the problems of parsing and reparsing text, use them.
Now learn perldoc, use package namespaces, use Exporter, start taking advantage of the flexibility to make the style suit you...
Perl gives you rope. Yes. But don't judge the limits of the language by people who commit maintainability suicide...
Should every program on your computer be talking with the outside world? Do you trust all of those programmers to consistently get security right? Heck, do you trust Microsoft to get security right?
How do you firewall bad applications? Think you know? Now let me throw a twist in. What happens when Microsoft implements a licensing and registration check by tunnelling over https? Oops, your computer will not boot without allowing that traffic, and you now have no idea what other information is being sent home.
No, SOAP and.NET are just plain bad ideas implemented by people who have not learned from past mistakes. Security is not an afterthought in any well-designed protocol.
Rules don't get you very far if you don't have a good relationship. But no parent can be with their kids 24 hours a day. (Parents really do try harder than most kids realize...)
Society accepts that parents have the right to treat their children in ways that no adult can be treated by another adult. For instance there is nothing unusual in having a parent ground a 10 year-old. Can a cop do that to an adult? Of course not!
I don't think that the police have the right to spy on an entire country. Yet I do believe that there is nothing wrong with a parent monitoring a minor. In fact I think that my wife's parents had exactly the right idea. They let their kids make their home the neighbourhood hangout. Why? So that they didn't have to worry about where their kids were and what they were up to.
Is that spying? In a literal sense it is. But the parents didn't sermonize, they didn't lay down a ton of rules. they didn't keep detailed logs. They just heard the kids talking with friends and didn't feel worried.
Likewise with the web let you kids go where they will. Check in on them in the same way you check out what they are watching on TV. Don't make it a secret or a big deal. But keep your eyes open.
The fact is that if we had a few more involved parents we would have a lot fewer script kiddies. And that would be a good thing.
Step 3: Monitor the webtraffic from the proxies. Have your monitoring be smart enough that you can label things as, "I know this is OK, don't mention it any more."
Step 4: Sit down and have some heart to heart conversations about anything that really bothers you.
By default don't get in the way. Have the rules match exactly what you are concerned about. And realistically, if step 4 fails, then you have real problems. You cannot block what your kid does at a friend's house, pretending that you can protect them by controlling what they do at yours is just stupid.
Have your own apt server, and have each desktop regularly fetch updates from it. Then when you want to roll out a new update, all you need to do is test it, put it on the apt server, and all of the desktops that are using it will update themselves.
This is very convenient for getting rid of any need to visit individual desktops to figure out who is using what custom packages. If they are using it, it gets updated. If they are not, it ignores the update.
This is being developed for the embedded market. OTOH it also has development environments running under X. Therefore anyone who wants can develop real applications to microwindows, and let people run it on whatever graphical system they want...
Fire off emails to both sites saying which you are using and why. One pair of eyeballs they will not notice, or even if they do they won't know how to interpret. A letter saying, "I will avoid your stuff" they will notice and there is no question how to interpret it.
I am talking about explaining to a married couple how to use a condom. Or explaining the relative risks of withdrawal and rhythm. For much of the 1900's in the USA it was against the law for doctors to even discuss the issue. (On the grounds that the information could pass to people who were not married and encourage immoral behaviour.)
I have met and discussed these issues with many people who were pro-life. Even those who do not use birth control themselves due to their religious beliefs (think Catholics) do not believe it to actually be murder to attempt to prevent contraception.
No statistics, but I know a lot of people who moved systems from SCO to Linux, and others who came to Linux for new systems because they were tired of SCO.
It really has to suck when you get letters from VARs saying things like not to bother about the support issue after all, we finally got frustrated enough to try it on Linux and it worked.
Personally I think that Caldera has to be interested. After all they are the Linux distributer who is most interested in targeting the VAR market...
You do not recover from a heroin addict. If you think you can, that is a short trip back into the trap. You can become clean, but for the rest of your life you exist in a minefield. Anything that can remind you of some association with heroin will bring the craving back.
For the rest of your life you are a heroin addict. Remember that and you might have a chance. Kid yourself about it and it is only a question of time until you are using it again.
And yeah. Riders are slops for the pigs in government.
However not all riders are pet projects. A lot are (like this one) laws that will remain in effect until someone goes through the expense of trying it in court.
The latter is what I would like to see discouraged. Rather than, "You scratch my back, I will scratch yours" make it, "WTF are you trying to do to my law?"
Cheers, Ben
PS Incidentally that is how equality for women wound up becoming law. JFK wanted a law banning racial discrimination. Opponents got women included since they thought it would sink the bill. Then JFK died, and the bill was passed in his memory with rider still attached...
I would like an amendment saying that if any part of a bill is ruled unconstitutional, the entire bill is rendered null and void. No ands, ifs, or buts. Don't play games with the Constitution.
Just something to discourage politions from tossing unconstitutional riders onto big bills...
If you are a medical practitioner dealing with drug treatment, it is important for you have information about illegal drugs. Including how people prepare them. Otherwise you won't be able to talk to your patients, and people in treatment centers won't know what they need to look for and take away from their patients.
Are doctors to be banned from learning how to do their jobs?
(This is not so far-fetched. For much of the 1900's it was against the law for physicians to explain anything about birth control to their patients. Reflect on that for a bit...)
Politicians do not run the government. They are merely caretakers for a set of largely absentee landlords known as the public. Congress normally runs things as they like (which is usually as they are bribed). However if the public appears to care, the rules change without warning.
Therefore the most important line in that to my reading is this:
TO LEAHY, THOSE NUMBERS translated into political power. ''If 20 million Napster users get cut off,'' he warned, ''even those senators who are not sure what that large screen on the desks in their office is are going to start hearing from those people.'' Without rapid movement to give Napster a license, he said, ''you'll feel pressure from Congress to create statutory licenses, and pressure to create a single fee to pay all concerned, and I'm not sure everybody will be happy with that.''
Up until 2 years the average citizen was not going to directly run afoul of intellectual property laws. Today that has changed. Congress is painfully aware of several items:
The internet is big.
Nobody knows how it changes the rules.
Whoever is seen as having stood in its way probably has no political future worth speaking of.
This is an election year.
That is why you have the two politicians who have arguably been the best friends that copyright has seen standing there and telling the record company that the rules have changed. In a big way.
Coincidentally over the last few days I have been doing some thinking on copyright and intellectual property. IANAL, I may be naive, etc. But I see this as a sign that the rules may be about to change in a big way.
We are living in interesting times, and I for one am fascinated with what may happen next.
One of the largest problems in poverty-stricken areas is education. Basic sanitation, care of diseases, how to keep crops productive, etc. Education does not proceed by trying to teach everyone. Instead you proceed by trying to identify key people and teach them, then rely on traditional networks to spread that knowledge.
Computers in every home is a silly goal. Computers in the third world are far more likely to be like television. A village may only have one with someone who can use it. But that one is a resource for the whole village.
If life is easier thinking in terms of rest mass you start using m_0.
It is just a renaming. But it is a renaming with conceptual content. Read The Feynman Lectures on Physics vol 1, chapter 15-9. Even if I get into the habit of never discussing relativistic mass, his point there will always be how I will understand E=mc^2. That mass is equivalent to energy. And unless someone explains otherwise I will always believe that that definition is the one that fits with Newton's original definition.
OTOH it won't be the only time that a key concept gets moved around winding up somewhere completely different. For instance the original definition of "continuous" was roughly what we today mean by "analytic". It is just a little disconcerting to be on the wrong end of such a name change without realizing it.
As for tensors, I had little problem doing it. As long as I didn't mix up what it meant. However I can really say that I didn't understand it until I saw the entire thing in completely different notation in differential geometry. If that sounds interesting to you, I recommend checking out Spivak. His elementary text is Calculus on Manifolds, and his advanced text is A Comprehensive Introduction to Differential Geometry. Both are recommended.
OTOH the difference between covariant and contravariant (or vector fields and forms in the language of differential geometers) is one that is in some sense meaningless to physicists in most contexts. Outside of GR you are unlikely to deal with situations where you don't want to use a coordinate system in which there is an obvious (usually trivial) metric. Differential geometers don't have it so easy. The idea of a metric is not integral to a manifold...
Incidentally have you seen the connection between contra vs co and the concept of a vector space and its dual? If you have not then I suggest looking that up, it is the same relationship except that the linear algebra version is somewhat simpler since there is a lot less going on.
My interest was math. Lemme look at my bookshelf. Here are the physics books I have with anything about relativity.
Feynman Lectures on Physics, vols 1-3, by Feynman Tensor Calculus, by Spain (I learned GR from this book. My copy is a 3rd edition from 1960.)
Both of them are from late 50's/early 60's and talk about relativistic mass. I have a few other physics books, but none about relativity. Lemme see without moving. A fluid mechanics book, one on group theory and physics, and a biography on Newton. 8 physics books (remember 3 volumes of Feynman), 2 of which are physics/math. Without moving I stopped counting at over 3 times as many math titles.
Until today I really hadn't realized that physicists were not using the concept of relativistic mass. It has been part of every treatment I have had (high-school, Feynman on my own, and GR), and I just took it for granted.
Besides which, the definition of relativistic mass is much closer to the original definition used by Newton. How else can you make sense of questions like asking if the ratio between inertial and gravitational mass is truly 1? (This was obviously one of the questions that Newton's work raised.)
After all either way you talk about the energy-momentum tensor, and everyone means the same thing by that.
OTOH using the convention that I was taught (am I dating myself with that comment?) mass means something closer to the classical concept. For instance mass is roughly how much gravitational force you exert on the world around you, and is how much of a tendancy you have to have inertia.
In fact if you use the original definition by Newton, mass is momentum divided by velocity and that figure just happens to be the figure he theorized got plugged into the calculation for gravity. Well in SR that definition clearly gives you relativistic mass, and in GR that clearly is the energy part of the energy-momentum tensor which shows that Newton was on the right track!
So going back to the roots of the idea, it certainly makes a lot of sense.
Vol 1. Chapter 16-4. Read it and get back to me on how crazy the definition I gave is.
Now when you step on a scale, the heat in your body is indeed part of that measurement. As is the air you displace, the thermal effects on the springs, and local variations in gravity. The effects of your body heat are lost in the noise, but they do indeed affect how strongly you are attracted to the Earth, and affect how strongly the Earth is attracted to you.
As for GR, and global conservation laws, you are absolutely and utterly wrong. Proof. GR is consistent with wormholes where things can move backwards in time. At one time the thing isn't there and suddenly it is - straight from the future. Non-conservation.
GR has 2 types of conservation laws of interest. Local conservation laws due to locally looking like SR. And global conservation laws when you place certain types of constraints on the space-time manifold. But without some sort of constraints you cannot even *state* what a global conservation law should look like.
As for my definition of mass, "Killing me", you are completely wrong. It doesn't matter which language you use, you are describing the same basic physics and you come out to the same basic answer.
As for Einstein's theory of special relativity, and Newton, Newton's own statements were nothing like what we are used to dealing with. For instance he said only that for every action there is an equal and opposite reaction along the same line. True. He said that momentum was conserved. True. He and his successors did not take into account that (relativistic) mass was not constant, but if you did then his statement is still inaccurate. When you state that force is equal to the rate of change of momentum, you are right. If you state that momentum is mv, you are still right if m is the relativistic mass. When you state that the rate of change of momentum is ma, you are assuming that mass is not changing. And that is what physicists did before relativity. But that wasn't Newton's statement, and Newton's words remain literally correct if you use relativistic mass and add in the fact that mass changes with velocity.
Oh, finally. If you use relativistic mass as your definition, then relativistic mass is the same thing as energy (albeit usually measured in different units) and therefore it is conserved. Nuclear bombs still work perfectly fine.
Which they darned well better because all it is is a slightly different notation for the same physics. The language you use to discuss why things go "boom" doesn't change the fact that they really do go "boom"!
Slashdot Mirror
Here is a clue.
The Samba folks don't publicize it, but they have found a number of buffer overflows in the stacks of every single OS out there. (They patched the ones they found in Linux.:-) A truly nasty critter would be set up to transmit itself using those overflows.
If done right you would get a worm or virus that can transmit from computer to computer without any manual intervention. There has to date been exactly one such on the internet. The Morris worm. It went out of its way to be nice, and it still shut down the Internet through sheer speed of reproduction.
You see getting a human in the loop slows things down. If you want to be truly nasty, automate it from start to finish. Then the first people will hear about it is when their networks go down.
Cheers,
Ben
For people who are serious about using encryption, the question is not whether in the future they will be able to use a method of encryption that can beat the methods of decryption then available, it is how long their secrets, transmitted today, will remain secret.
Some forms of encryption are good for discouraging casual novices. Some take a little time and are fine for short-lived secrets. Some will cause the NSA to blink. Some will last for a good while.
But the standard public-key encryption mechanism in use today will not survive the potential of quantum computers. So, for instance, digitally signed documents have a lifetime of a few decades before the signatures can be forged.
This is fine for credit card purchases. It may not be fine for some kinds of legal contracts.
Cheers,
Ben
Or else you never learned the language.
The "funny symbols" define a miniature grammar. Learn that grammar and it gives you guidelines about how to think about hashes etc. (Guidelines such as what you should name them.) Next use strict to stop pointing your gun footwards. Warnings exist for a reason. Turn them on as well. Finally avoid default variables except where they are necessary.
Now follow basic sane programming guidelines and Perl is perfectly readable.
It gets a lot better when you start using it like it was meant to be used. For instance the language is a list-oriented language for a reason. There are a lot of constructs that are syntactic sugar. Use them wisely. Note that map() and grep() give you all of the power of a pipeline without the problems of parsing and reparsing text, use them.
Now learn perldoc, use package namespaces, use Exporter, start taking advantage of the flexibility to make the style suit you...
Perl gives you rope. Yes. But don't judge the limits of the language by people who commit maintainability suicide...
Cheers,
Ben
Do you understand the mix of technologies?
.NET are just plain bad ideas implemented by people who have not learned from past mistakes. Security is not an afterthought in any well-designed protocol.
Should every program on your computer be talking with the outside world? Do you trust all of those programmers to consistently get security right? Heck, do you trust Microsoft to get security right?
How do you firewall bad applications? Think you know? Now let me throw a twist in. What happens when Microsoft implements a licensing and registration check by tunnelling over https? Oops, your computer will not boot without allowing that traffic, and you now have no idea what other information is being sent home.
No, SOAP and
*sigh*
Ben
Rules don't get you very far if you don't have a good relationship. But no parent can be with their kids 24 hours a day. (Parents really do try harder than most kids realize...)
Cheers,
Ben
...when you grow up.
Society accepts that parents have the right to treat their children in ways that no adult can be treated by another adult. For instance there is nothing unusual in having a parent ground a 10 year-old. Can a cop do that to an adult? Of course not!
I don't think that the police have the right to spy on an entire country. Yet I do believe that there is nothing wrong with a parent monitoring a minor. In fact I think that my wife's parents had exactly the right idea. They let their kids make their home the neighbourhood hangout. Why? So that they didn't have to worry about where their kids were and what they were up to.
Is that spying? In a literal sense it is. But the parents didn't sermonize, they didn't lay down a ton of rules. they didn't keep detailed logs. They just heard the kids talking with friends and didn't feel worried.
Likewise with the web let you kids go where they will. Check in on them in the same way you check out what they are watching on TV. Don't make it a secret or a big deal. But keep your eyes open.
The fact is that if we had a few more involved parents we would have a lot fewer script kiddies. And that would be a good thing.
Regards,
Ben
O'Reilly
See, Visual Basic on the front page. They even have a whole domain devoted to the evil stuff!
The moral of the story? Be careful with hard and fast rules...
:-)
Cheers,
Ben
Step 1: Put up an internal firewall.
Step 2: Set up proxies.
Step 3: Monitor the webtraffic from the proxies. Have your monitoring be smart enough that you can label things as, "I know this is OK, don't mention it any more."
Step 4: Sit down and have some heart to heart conversations about anything that really bothers you.
By default don't get in the way. Have the rules match exactly what you are concerned about. And realistically, if step 4 fails, then you have real problems. You cannot block what your kid does at a friend's house, pretending that you can protect them by controlling what they do at yours is just stupid.
Cheers,
Ben
Here is the idea.
Have your own apt server, and have each desktop regularly fetch updates from it. Then when you want to roll out a new update, all you need to do is test it, put it on the apt server, and all of the desktops that are using it will update themselves.
This is very convenient for getting rid of any need to visit individual desktops to figure out who is using what custom packages. If they are using it, it gets updated. If they are not, it ignores the update.
:-)
Cheers,
Ben
Link here.
This is being developed for the embedded market. OTOH it also has development environments running under X. Therefore anyone who wants can develop real applications to microwindows, and let people run it on whatever graphical system they want...
Cheers,
Ben
Don't just use a competitor.
Fire off emails to both sites saying which you are using and why. One pair of eyeballs they will not notice, or even if they do they won't know how to interpret. A letter saying, "I will avoid your stuff" they will notice and there is no question how to interpret it.
Cheers,
Ben
Please read more carefully.
I was not talking pro-life vs pro-choice.
I am talking about explaining to a married couple how to use a condom. Or explaining the relative risks of withdrawal and rhythm. For much of the 1900's in the USA it was against the law for doctors to even discuss the issue. (On the grounds that the information could pass to people who were not married and encourage immoral behaviour.)
I have met and discussed these issues with many people who were pro-life. Even those who do not use birth control themselves due to their religious beliefs (think Catholics) do not believe it to actually be murder to attempt to prevent contraception.
Regards,
Ben
No statistics, but I know a lot of people who moved systems from SCO to Linux, and others who came to Linux for new systems because they were tired of SCO.
It really has to suck when you get letters from VARs saying things like not to bother about the support issue after all, we finally got frustrated enough to try it on Linux and it worked.
Personally I think that Caldera has to be interested. After all they are the Linux distributer who is most interested in targeting the VAR market...
Cheers,
Ben
You do not recover from a heroin addict. If you think you can, that is a short trip back into the trap. You can become clean, but for the rest of your life you exist in a minefield. Anything that can remind you of some association with heroin will bring the craving back.
For the rest of your life you are a heroin addict. Remember that and you might have a chance. Kid yourself about it and it is only a question of time until you are using it again.
I am serious.
Regards,
Ben
And yeah. Riders are slops for the pigs in government.
However not all riders are pet projects. A lot are (like this one) laws that will remain in effect until someone goes through the expense of trying it in court.
The latter is what I would like to see discouraged. Rather than, "You scratch my back, I will scratch yours" make it, "WTF are you trying to do to my law?"
Cheers,
Ben
PS Incidentally that is how equality for women wound up becoming law. JFK wanted a law banning racial discrimination. Opponents got women included since they thought it would sink the bill. Then JFK died, and the bill was passed in his memory with rider still attached...
I would like an amendment saying that if any part of a bill is ruled unconstitutional, the entire bill is rendered null and void. No ands, ifs, or buts. Don't play games with the Constitution.
Just something to discourage politions from tossing unconstitutional riders onto big bills...
Cheers,
Ben
If you are a medical practitioner dealing with drug treatment, it is important for you have information about illegal drugs. Including how people prepare them. Otherwise you won't be able to talk to your patients, and people in treatment centers won't know what they need to look for and take away from their patients.
Are doctors to be banned from learning how to do their jobs?
(This is not so far-fetched. For much of the 1900's it was against the law for physicians to explain anything about birth control to their patients. Reflect on that for a bit...)
Cheers,
Ben
Politicians do not run the government. They are merely caretakers for a set of largely absentee landlords known as the public. Congress normally runs things as they like (which is usually as they are bribed). However if the public appears to care, the rules change without warning.
Therefore the most important line in that to my reading is this:
Up until 2 years the average citizen was not going to directly run afoul of intellectual property laws. Today that has changed. Congress is painfully aware of several items:
That is why you have the two politicians who have arguably been the best friends that copyright has seen standing there and telling the record company that the rules have changed. In a big way.
Coincidentally over the last few days I have been doing some thinking on copyright and intellectual property. IANAL, I may be naive, etc. But I see this as a sign that the rules may be about to change in a big way.
We are living in interesting times, and I for one am fascinated with what may happen next.
Cheers,
Ben
The Nasa Spaceflight Web link you give commits this sin.
/.ed..?
Or are you trying to get their administrator's email box
Cheers,
Ben
Many people are missing the point.
One of the largest problems in poverty-stricken areas is education. Basic sanitation, care of diseases, how to keep crops productive, etc. Education does not proceed by trying to teach everyone. Instead you proceed by trying to identify key people and teach them, then rely on traditional networks to spread that knowledge.
Computers in every home is a silly goal. Computers in the third world are far more likely to be like television. A village may only have one with someone who can use it. But that one is a resource for the whole village.
Cheers,
Ben
If life is easier thinking in terms of rest mass you start using m_0.
It is just a renaming. But it is a renaming with conceptual content. Read The Feynman Lectures on Physics vol 1, chapter 15-9. Even if I get into the habit of never discussing relativistic mass, his point there will always be how I will understand E=mc^2. That mass is equivalent to energy. And unless someone explains otherwise I will always believe that that definition is the one that fits with Newton's original definition.
OTOH it won't be the only time that a key concept gets moved around winding up somewhere completely different. For instance the original definition of "continuous" was roughly what we today mean by "analytic". It is just a little disconcerting to be on the wrong end of such a name change without realizing it.
As for tensors, I had little problem doing it. As long as I didn't mix up what it meant. However I can really say that I didn't understand it until I saw the entire thing in completely different notation in differential geometry. If that sounds interesting to you, I recommend checking out Spivak. His elementary text is Calculus on Manifolds, and his advanced text is A Comprehensive Introduction to Differential Geometry. Both are recommended.
OTOH the difference between covariant and contravariant (or vector fields and forms in the language of differential geometers) is one that is in some sense meaningless to physicists in most contexts. Outside of GR you are unlikely to deal with situations where you don't want to use a coordinate system in which there is an obvious (usually trivial) metric. Differential geometers don't have it so easy. The idea of a metric is not integral to a manifold...
Incidentally have you seen the connection between contra vs co and the concept of a vector space and its dual? If you have not then I suggest looking that up, it is the same relationship except that the linear algebra version is somewhat simpler since there is a lot less going on.
Cheers,
Ben
My interest was math. Lemme look at my bookshelf. Here are the physics books I have with anything about relativity.
Feynman Lectures on Physics, vols 1-3, by Feynman
Tensor Calculus, by Spain (I learned GR from this book. My copy is a 3rd edition from 1960.)
Both of them are from late 50's/early 60's and talk about relativistic mass. I have a few other physics books, but none about relativity. Lemme see without moving. A fluid mechanics book, one on group theory and physics, and a biography on Newton. 8 physics books (remember 3 volumes of Feynman), 2 of which are physics/math. Without moving I stopped counting at over 3 times as many math titles.
Until today I really hadn't realized that physicists were not using the concept of relativistic mass. It has been part of every treatment I have had (high-school, Feynman on my own, and GR), and I just took it for granted.
Besides which, the definition of relativistic mass is much closer to the original definition used by Newton. How else can you make sense of questions like asking if the ratio between inertial and gravitational mass is truly 1? (This was obviously one of the questions that Newton's work raised.)
Cheers,
Ben
After all either way you talk about the energy-momentum tensor, and everyone means the same thing by that.
OTOH using the convention that I was taught (am I dating myself with that comment?) mass means something closer to the classical concept. For instance mass is roughly how much gravitational force you exert on the world around you, and is how much of a tendancy you have to have inertia.
In fact if you use the original definition by Newton, mass is momentum divided by velocity and that figure just happens to be the figure he theorized got plugged into the calculation for gravity. Well in SR that definition clearly gives you relativistic mass, and in GR that clearly is the energy part of the energy-momentum tensor which shows that Newton was on the right track!
So going back to the roots of the idea, it certainly makes a lot of sense.
Cheers,
Ben
Vol 1. Chapter 16-4. Read it and get back to me on how crazy the definition I gave is.
Now when you step on a scale, the heat in your body is indeed part of that measurement. As is the air you displace, the thermal effects on the springs, and local variations in gravity. The effects of your body heat are lost in the noise, but they do indeed affect how strongly you are attracted to the Earth, and affect how strongly the Earth is attracted to you.
As for GR, and global conservation laws, you are absolutely and utterly wrong. Proof. GR is consistent with wormholes where things can move backwards in time. At one time the thing isn't there and suddenly it is - straight from the future. Non-conservation.
GR has 2 types of conservation laws of interest. Local conservation laws due to locally looking like SR. And global conservation laws when you place certain types of constraints on the space-time manifold. But without some sort of constraints you cannot even *state* what a global conservation law should look like.
As for my definition of mass, "Killing me", you are completely wrong. It doesn't matter which language you use, you are describing the same basic physics and you come out to the same basic answer.
As for Einstein's theory of special relativity, and Newton, Newton's own statements were nothing like what we are used to dealing with. For instance he said only that for every action there is an equal and opposite reaction along the same line. True. He said that momentum was conserved. True. He and his successors did not take into account that (relativistic) mass was not constant, but if you did then his statement is still inaccurate. When you state that force is equal to the rate of change of momentum, you are right. If you state that momentum is mv, you are still right if m is the relativistic mass. When you state that the rate of change of momentum is ma, you are assuming that mass is not changing. And that is what physicists did before relativity. But that wasn't Newton's statement, and Newton's words remain literally correct if you use relativistic mass and add in the fact that mass changes with velocity.
Oh, finally. If you use relativistic mass as your definition, then relativistic mass is the same thing as energy (albeit usually measured in different units) and therefore it is conserved. Nuclear bombs still work perfectly fine.
Which they darned well better because all it is is a slightly different notation for the same physics. The language you use to discuss why things go "boom" doesn't change the fact that they really do go "boom"!
Regards,
Ben
So I happen to think about it like Feynman did. That is hardly the worst possible sin.
What I said is perfectly correct, and the formulation that I used is mathematically cleaner, albeit less useful for particle physicists.
Regards,
Ben