If the hijacker has no previous criminal record, as with 9/11 IIRC, why would this possibly be of use?
I posted elsewhere in this thread, but here's my basic feeling.
I don't think this will do squat for actually stopping terrorism directly.
What it will do is make it much much harder for someone to spoof an identity (ie, fake passport) for coming into the US.
Secondly, if a tourist does a crime and leaves fingerprints then it can help track that down. Regarding fingerprinting, I remember getting fingerprinted when I was little at school, do all Americans get fingerprinted as routine? If so, then it kind of makes sense to treat visitors as we do ourselves.
Anyway, the one good thing about this is that they're apparently making all countries citizens get fingerprinted, and hence all visitors have a level playing field. So it'll make a visitor from Morocco feel less humiliated at immigration than a visitor from Spain, for example.
All it does is get my identity into a database for a foreign country to use against me.
Okay, I'll probably get flamed for this, but what the hell, it's friday.
I really don't see what the big deal is regarding fingerprints. I mean, you can't do anything useful with a fingerprint (excepting tin-foil-people's theories that DNA from the fingerprint oil will be used in some secret government lab somewhere. Or that the gubbmint will 'spoof' the fingerprint and try to frame someone in a crime.)
This is happening only at a border. I do think that a country has every right to know exactly who is entering it's borders. Ie, the reason every country has an immigration department and all countries issue passports. The fingerprinting is, in my view, basically a secure passport that can't be spoofed (well, not easily at least).
Now if there were photo and fingerprint stations around the country monitoring who did what and went where, then that's a whole different thing that I'll be against 100%.
But fingerprinting and photographs, invading privacy? IMHO, I don't get it. They're not taking pictures of your genitals, and your photo is on your passport so you should have no shame of a record of you coming into a country anyway.
Now I do agree with you that it'll probably not do jack for stopping terrorists. But the real issue is this - does a country have a right to know exactly who enters it's borders or not?
And finally, at least now ALL countries are getting fingerprinted, which is what they should have done since the beginning, instead of only targetting specific countries. At least that universal policy wouldn't make some people feel like assholes (aka what Brazil is doing).
I no longer do physics (I'm a software developer now) because I could see the trend that it didn't matter what you wrote, but that you wrote a lot of it. I still toy with the idea of going back and doing some novel research. However, if I do, I intend to publish it on my own website, since I have no need to pad my resume' with a long list of publications, I would just want to get the results out there and indexed by google or other search engines, so anyone who cares and is looking could get instant access to it.
Hi, I'm a 4th-year grad physics student that came back to school after 3 years of doing engineering-type research (hardware + software) after my undergrad. So I see where you're coming from.
What you want already exists and is the arxiv . You can put any papers here, and people can download them, etc. I don't know what limitations there are, like how long they'll keep your papers or things like that. But this is exactly what you want. It even allows searches based on various keywords.
Some people publish here because it's quick, and then get a peer-reviewed journal (like PRL) to publish it just for more 'authenticity'. But that's not necessary, and some people publish there and don't worry about future peer review.
I regularly look at the daily new writeups in condensed matter physics, and it's amazing how many there are, and many are by very respected researchers.
Anyway, on the other side of the coin, there is something to be said for peer-review. It does help 'weed' out some of the bogus stuff that will inevitably appear.
As for the publish or perish, yeah, that's what happens when a society uses some factor for judging 'worth'. Ie, in the business world it's money and people thus try to maximize their money. For physics, some people will try to optimize their publications. Look at Schon, the guy that faked his data 2 years ago, and finally got caught. He was putting out several Nature and Science articles a year, which is nearly deity status in the physics world. He couldn't keep up with this rate, and at some point had to fabricate his data.
The high-energy theorists I know here at JHU still publish in other journals. In fact, several physicists here publish something in the arxiv first, to 'get it out first', and then work to get it in a journal. But some journals, (Nature, IIRC) don't let you do this.
But anyway, as someone else said, there's ALOT to be said for the peer review model. You can see this even at some conferences, where anybody can attend if they pay the registration fee. You basically see science trolls at some of the sessions, just shouting down the speaker with false claims, or saying the talk is obvious (when it's not), etc. It's kind of weird to see 'professionals' trolling.
But back on topic, the arxiv has lots of articles, and anybody can publish there. But peer review is worth ALOT. At least with the condensed matter people I work with we all strive to make it to the standard journals.
Anybody know who 'owns' the article? I would guess the journal does. But on the homepages of some researchers they have the PDF files available for download. I wonder if that's technically legal or not.
Also, AFAIK, it still costs money for the author to publish in many journals. But the subject matter is not subsequently free for all to read. But in the old days the authors would usually get a stack of preprints, and send these to various colleagues upon request.
Most of the cutting edge stuff just happened back in the mid 80's, and now, a few other groups are starting up again with this area.
I thought fluids was still a relatively fresh field with the recent research of 'complex fluids'. I've even seen several colloquiums and lectures in the condensed matter group of the physics department here at JHU on such fluids.
You can't flash words any faster then the computer screen updates.
Absolutely. I was within the refresh limits of a CGA monitor, the values of which I don't remember.
'By eye' there was a slight difference noticeable w/ the flashing of the words on the screen. they were too short to be read, but i could discern a slight difference w/ duration.
You need much more sophisticated equipment then any modern computer monitor, let alone a reasonably-priced 1992 monitor, can provide you to test this reasonably.
Absolutely. But remember this was a high school research project, done entirely on my own, without a mentor or advisor. Even in college and grad school you have a research adviser to guide you through technological limitations as these.
It was limited, but still interested (at least to me).
I actually did a research project back in high school (1992) where I made up a bunch of fake vocabulary words and flashed them on the computer screen for varying durations. While at the longest durations the flashing was somewhat noticeable, it was still too quick to read the words.
I told the students they were being tested on the ability of typing in words to help them remember their meanings. Meanwhile other words and definitions were being flashed on the screen. At the end of the session (10-15 mins i think) they were given a test with both sets of words, and only the subliminal words were counted.
I tested 3 varying durations of the messages, and one of the durations actually had noticeable score above the statistical average for guessing. I was getting psyched. Then I realized I needed a control group too, where I didn't flash anything on the screen. It turned out the control group got nearly the same score as that one above-average group.
I did statistical ANOVA analysis, and basically there was no significant correlation between the group scores and the flashing duration.
It was still a fun project to do. And I got to present the project at the Monmouth Junior Science Symposium too, which ironically happens to be running today and tomorrow.
Missing are the brilliant types of engineers who can find an answer to a problem around them without needing a bigger budget and stuff.
I took a grad-level physics-based electromagnetism class last year, and picked up some supplementary E&M books from the library. One of them was from an engineering slant, and actually described the following problem and it's solution.
Farmers wanted a way to keep pigs warm in the winter. So they estimated the thickness of a layer of fat under the pig's skin, determined permittivities and permeabilities of the fat and the muscle-layers underneath the fat, and solved the boundary conditions of Maxwell's equations in the presence of RF radiation.
The result was that they effectively made a low-cost 'microwave oven' tuned to the pig's fat layer, which would keep them warm and still be relatively cheap (ie, put the heater in the pen without worrying about walls, etc).
Sorry, it's like 2 days later and I just see your reply now.
No, you can easily see that insanely large n makes the 1st-order Taylor expansion worthless in this case. If x approaches zero, the error approaches zero, but as n->infinity you get big problems.
Suppose you want to calculate (0.98)^3. This is 0.941192. Using the 1st-order Taylor expansion, one gets 1-3*0.2, or 0.94. Close, but obvious errors. In this case, n was 3 and x was 0.02.
Now suppose you want (0.98)^200. This is about 0.017588 or so. But using only 1st-order Taylor expansion one gets 1-200*0.02, or -3. Obviously there's a major problem there.
One simple way to remedy this for large n (used in statistical mechanics, for example, where n can be 10^23 or larger) is to Taylor expand the natural log of the function. So expanding ln((1-x)^n)=n*ln(1-x)~=-nx. Taking the antilog, one gets (1-x)^n for large n ~= exp(-nx).
Plug in the numbers for the bad example previously, n=200, x=0.2, and the answer (using python) is 0.01831. not great, but at least within order of magnitude.
Re:"hazards and risks are poorly understood"
on
Buckyballs Kill Fish
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· Score: 1
C-60 may be a large molecule but it's still small on the quantum scale, and hence has atomic-like states.
But don't just take my word for it.
Why don't you check out this java applet . It shows the time-dependent Hamiltonian, diagonalizes it for you, and then shows what the energy eigenstate wavefunctions for the C-60 molecule look like.
Hint, at low energies (large wavelengths) they look just like the spherical harmonics. In other words there is no sense of the 'structure' of the C-60 molecule. At the larger energies, though, the wavefunctions and energy levels deviate from the spherical harmonics as they can now discern the hexagon/pentagon planes.
You must have missed the entire point of my post. I was showing how mu exactly is B/(1+B/A). This will always be true for the 2-body system. There is only one assumption I made, which was for the satellite that A>>B. This assumption doesn't do anything until it's realized with a 1st-order Taylor expansion.
The whole point of the Taylor expansion was to give an estimate of the difference between B and mu, and in this case it's -B^2/A (to 1st order). If you don't like the expansion then keep the exact form, or take the taylor expansion to higher orders.
Anyway, since you missed the mathematics of my post, here's a recap of simple Taylor expansions.
Binomial expansion :
for 1>>|x| (and n not insanely large), (1+x)^n ~= 1+(x*n)
So 1/(1+x) ~= 1-x
Recall mu=B/(1+B/A) exactly. To within some specified precision, mu~=B-(B^2/A). You can compare exact to approximate answers to see what the error terms will be.
you can only have over 50% w/ blackjack if you can satisfactorily count cards to push the percentage above 50%.
If you can do that successfully, compensate for mid-chute shuffling, and still be over 50% then you might be right. you'll also have a very stupid casino staff to boot.
Orbital mechanics tells us that the velocity of an orbiting object is dependent on the mass of the object you're orbiting, and the distance you are from the surface.
Not exactly true. When solving the two-body system, a number of coordinate transformations change the equations of motion into a simple one-body equation that can be solved exactly. The mass in the transformed one-body system is called the reduced mass, which is defined as mu=(A*B)/(A+B), where A and B are the masses of the two bodies in question.
Assuming A>>B (ie, Earth is much greater than the mass of a satellite), this can be rewritten exactly as mu=B/(1+B/A), or w/ a first-order taylor expansion as mu=B-B^2/A. For a standard communications satellite, the second term is approximately 10^-18 times smaller, and can realistically be dropped, and the mass of the satellite is to within measurable uncertainties B.
But you're wrong in general when you say it's independent of the mass of the object it's orbiting. In the system of the moon orbitting Earth, there's about 1% error by replacing the reduced mass by moon's mass. For a more dramatic example look at a binary star system where one star has 3x the mass of another.
I certainly hope that his Physics research isn't as sloppy as the google news search that he ran as the basis of this article. SNIP Ten minutes of fact-checking would have revealed that.
Why don't you look up some of his physics papers then, instead of extrapolating what you perceive is a misquote into his physics research. 10 minutes of fact-checking could show you.
For example, here is a link of 12 articles on the arxiv. Of course this is a significantly small subset of his cumulative research publications.
Also, I don't see where he cites the $1 trillion figure from an AP reporter. What I saw in the article it says he estimated that $1 trillion himself from NASA reports, to 10% or so.
Re:I caught an interview about infinty
on
Everything and More
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· Score: 2, Interesting
That exact concept (minus the child's misunderstanding) was in the children's book "The Phantom Tollbooth", which was a really cool kids book that actually got me thinking about alot of cool ideas, both scientifically and philosophically.
Basically, there's a town that mines 'numbers' from the ground. They say they mine every number. The kid asks what's the biggest number they get, and they show him a huge number 8. he then says, "no, i mean, what's the longest number" and they show him a number 25 that's really really wide.
Then they get what he's trying to ask, and tell him that they mine every number there is, and ask him, like in your BBC quote, to name the largest number he can think of. he says something like 99999999999. But they go through the rigamarole of adding 1, etc.
It also put global conflicts into perspective, as there was a letter city that did things with letters, and the number people and the letter people hated each other. A peacemaker, trying to better their world, made them each come to a common agreement on something. They wound up agreeing that they disagreed! not so different from the real world.
The parent still brings up some valid points. Remember how a few months after 9/11 the Department of Immigration (or whatever it's called) sent the valid work permits and visas to one of the Al Queda pilots of 9/11. And these were processed AFTER 9/11. So obviously there are major flaws in the system somewhere.
I guess I'm old fashioned, but I thought Citizen Kane was absolutely amazing. Even more so that despite being 50 years old, it's still every bit as relevent today as it was then.
I saw him on an interview on TV a few days ago. He claimed Lyme's Disease came from this lab too, because Lyme Connecticut is relatively nearby, and there were some experiments at the lab on ticks. He didn't cite much evidence on the show beyond vague suppositions like this, though.
Anyway, whether you believe him or not, keep in mind he's marketing his book. Any controversy he stirs up will increase his sales (aka 'The Passion') and give him more profit. I tend to believe his stance is about as biased as the White House press secretary. But it's still more data points on the graph, even if they might have larger error bars.
Slashdot Mirror
I posted elsewhere in this thread, but here's my basic feeling.
I don't think this will do squat for actually stopping terrorism directly.
What it will do is make it much much harder for someone to spoof an identity (ie, fake passport) for coming into the US.
Secondly, if a tourist does a crime and leaves fingerprints then it can help track that down. Regarding fingerprinting, I remember getting fingerprinted when I was little at school, do all Americans get fingerprinted as routine? If so, then it kind of makes sense to treat visitors as we do ourselves.
Anyway, the one good thing about this is that they're apparently making all countries citizens get fingerprinted, and hence all visitors have a level playing field. So it'll make a visitor from Morocco feel less humiliated at immigration than a visitor from Spain, for example.
Okay, I'll probably get flamed for this, but what the hell, it's friday.
I really don't see what the big deal is regarding fingerprints. I mean, you can't do anything useful with a fingerprint (excepting tin-foil-people's theories that DNA from the fingerprint oil will be used in some secret government lab somewhere. Or that the gubbmint will 'spoof' the fingerprint and try to frame someone in a crime.)
This is happening only at a border. I do think that a country has every right to know exactly who is entering it's borders. Ie, the reason every country has an immigration department and all countries issue passports. The fingerprinting is, in my view, basically a secure passport that can't be spoofed (well, not easily at least).
Now if there were photo and fingerprint stations around the country monitoring who did what and went where, then that's a whole different thing that I'll be against 100%.
But fingerprinting and photographs, invading privacy? IMHO, I don't get it. They're not taking pictures of your genitals, and your photo is on your passport so you should have no shame of a record of you coming into a country anyway.
Now I do agree with you that it'll probably not do jack for stopping terrorists. But the real issue is this - does a country have a right to know exactly who enters it's borders or not?
And finally, at least now ALL countries are getting fingerprinted, which is what they should have done since the beginning, instead of only targetting specific countries. At least that universal policy wouldn't make some people feel like assholes (aka what Brazil is doing).
Hi, I'm a 4th-year grad physics student that came back to school after 3 years of doing engineering-type research (hardware + software) after my undergrad. So I see where you're coming from.
What you want already exists and is the arxiv . You can put any papers here, and people can download them, etc. I don't know what limitations there are, like how long they'll keep your papers or things like that. But this is exactly what you want. It even allows searches based on various keywords.
Some people publish here because it's quick, and then get a peer-reviewed journal (like PRL) to publish it just for more 'authenticity'. But that's not necessary, and some people publish there and don't worry about future peer review.
I regularly look at the daily new writeups in condensed matter physics, and it's amazing how many there are, and many are by very respected researchers.
Anyway, on the other side of the coin, there is something to be said for peer-review. It does help 'weed' out some of the bogus stuff that will inevitably appear.
As for the publish or perish, yeah, that's what happens when a society uses some factor for judging 'worth'. Ie, in the business world it's money and people thus try to maximize their money. For physics, some people will try to optimize their publications. Look at Schon, the guy that faked his data 2 years ago, and finally got caught. He was putting out several Nature and Science articles a year, which is nearly deity status in the physics world. He couldn't keep up with this rate, and at some point had to fabricate his data.
But anyway, as someone else said, there's ALOT to be said for the peer review model. You can see this even at some conferences, where anybody can attend if they pay the registration fee. You basically see science trolls at some of the sessions, just shouting down the speaker with false claims, or saying the talk is obvious (when it's not), etc. It's kind of weird to see 'professionals' trolling.
But back on topic, the arxiv has lots of articles, and anybody can publish there. But peer review is worth ALOT. At least with the condensed matter people I work with we all strive to make it to the standard journals.
Also, AFAIK, it still costs money for the author to publish in many journals. But the subject matter is not subsequently free for all to read. But in the old days the authors would usually get a stack of preprints, and send these to various colleagues upon request.
I thought fluids was still a relatively fresh field with the recent research of 'complex fluids'. I've even seen several colloquiums and lectures in the condensed matter group of the physics department here at JHU on such fluids.
Absolutely. I was within the refresh limits of a CGA monitor, the values of which I don't remember.
'By eye' there was a slight difference noticeable w/ the flashing of the words on the screen. they were too short to be read, but i could discern a slight difference w/ duration.
You need much more sophisticated equipment then any modern computer monitor, let alone a reasonably-priced 1992 monitor, can provide you to test this reasonably.
Absolutely. But remember this was a high school research project, done entirely on my own, without a mentor or advisor. Even in college and grad school you have a research adviser to guide you through technological limitations as these.
It was limited, but still interested (at least to me).
I know, I didn't say subliminal messages don't work in general. I just didn't see any effects of them in this specific representation.
seriously, even if you're trolling me, thanks!
I told the students they were being tested on the ability of typing in words to help them remember their meanings. Meanwhile other words and definitions were being flashed on the screen. At the end of the session (10-15 mins i think) they were given a test with both sets of words, and only the subliminal words were counted.
I tested 3 varying durations of the messages, and one of the durations actually had noticeable score above the statistical average for guessing. I was getting psyched. Then I realized I needed a control group too, where I didn't flash anything on the screen. It turned out the control group got nearly the same score as that one above-average group.
I did statistical ANOVA analysis, and basically there was no significant correlation between the group scores and the flashing duration.
It was still a fun project to do. And I got to present the project at the Monmouth Junior Science Symposium too, which ironically happens to be running today and tomorrow.
I took a grad-level physics-based electromagnetism class last year, and picked up some supplementary E&M books from the library. One of them was from an engineering slant, and actually described the following problem and it's solution.
Farmers wanted a way to keep pigs warm in the winter. So they estimated the thickness of a layer of fat under the pig's skin, determined permittivities and permeabilities of the fat and the muscle-layers underneath the fat, and solved the boundary conditions of Maxwell's equations in the presence of RF radiation.
The result was that they effectively made a low-cost 'microwave oven' tuned to the pig's fat layer, which would keep them warm and still be relatively cheap (ie, put the heater in the pen without worrying about walls, etc).
Kind of cool, but disturbing in a way too.
No, you can easily see that insanely large n makes the 1st-order Taylor expansion worthless in this case. If x approaches zero, the error approaches zero, but as n->infinity you get big problems.
Suppose you want to calculate (0.98)^3. This is 0.941192. Using the 1st-order Taylor expansion, one gets 1-3*0.2, or 0.94. Close, but obvious errors. In this case, n was 3 and x was 0.02.
Now suppose you want (0.98)^200. This is about 0.017588 or so. But using only 1st-order Taylor expansion one gets 1-200*0.02, or -3. Obviously there's a major problem there.
One simple way to remedy this for large n (used in statistical mechanics, for example, where n can be 10^23 or larger) is to Taylor expand the natural log of the function. So expanding ln((1-x)^n)=n*ln(1-x)~=-nx. Taking the antilog, one gets (1-x)^n for large n ~= exp(-nx).
Plug in the numbers for the bad example previously, n=200, x=0.2, and the answer (using python) is 0.01831. not great, but at least within order of magnitude.
But don't just take my word for it. Why don't you check out this java applet . It shows the time-dependent Hamiltonian, diagonalizes it for you, and then shows what the energy eigenstate wavefunctions for the C-60 molecule look like.
Hint, at low energies (large wavelengths) they look just like the spherical harmonics. In other words there is no sense of the 'structure' of the C-60 molecule. At the larger energies, though, the wavefunctions and energy levels deviate from the spherical harmonics as they can now discern the hexagon/pentagon planes.
The whole point of the Taylor expansion was to give an estimate of the difference between B and mu, and in this case it's -B^2/A (to 1st order). If you don't like the expansion then keep the exact form, or take the taylor expansion to higher orders.
Anyway, since you missed the mathematics of my post, here's a recap of simple Taylor expansions.
Binomial expansion : for 1>>|x| (and n not insanely large), (1+x)^n ~= 1+(x*n)
So 1/(1+x) ~= 1-x
Recall mu=B/(1+B/A) exactly. To within some specified precision, mu~=B-(B^2/A). You can compare exact to approximate answers to see what the error terms will be.
you can only have over 50% w/ blackjack if you can satisfactorily count cards to push the percentage above 50%.
If you can do that successfully, compensate for mid-chute shuffling, and still be over 50% then you might be right. you'll also have a very stupid casino staff to boot.
Not exactly true. When solving the two-body system, a number of coordinate transformations change the equations of motion into a simple one-body equation that can be solved exactly. The mass in the transformed one-body system is called the reduced mass, which is defined as mu=(A*B)/(A+B), where A and B are the masses of the two bodies in question.
Assuming A>>B (ie, Earth is much greater than the mass of a satellite), this can be rewritten exactly as mu=B/(1+B/A), or w/ a first-order taylor expansion as mu=B-B^2/A. For a standard communications satellite, the second term is approximately 10^-18 times smaller, and can realistically be dropped, and the mass of the satellite is to within measurable uncertainties B.
But you're wrong in general when you say it's independent of the mass of the object it's orbiting. In the system of the moon orbitting Earth, there's about 1% error by replacing the reduced mass by moon's mass. For a more dramatic example look at a binary star system where one star has 3x the mass of another.
Do that 100x and see how well you fare against the change machine.
The machine with the best odds in the casino is the change machine. Play it and you break even every time, better than every other game in the place.
SNIP Ten minutes of fact-checking would have revealed that.
Why don't you look up some of his physics papers then, instead of extrapolating what you perceive is a misquote into his physics research. 10 minutes of fact-checking could show you.
For example, here is a link of 12 articles on the arxiv. Of course this is a significantly small subset of his cumulative research publications.
Also, I don't see where he cites the $1 trillion figure from an AP reporter. What I saw in the article it says he estimated that $1 trillion himself from NASA reports, to 10% or so.
Basically, there's a town that mines 'numbers' from the ground. They say they mine every number. The kid asks what's the biggest number they get, and they show him a huge number 8. he then says, "no, i mean, what's the longest number" and they show him a number 25 that's really really wide.
Then they get what he's trying to ask, and tell him that they mine every number there is, and ask him, like in your BBC quote, to name the largest number he can think of. he says something like 99999999999. But they go through the rigamarole of adding 1, etc.
It also put global conflicts into perspective, as there was a letter city that did things with letters, and the number people and the letter people hated each other. A peacemaker, trying to better their world, made them each come to a common agreement on something. They wound up agreeing that they disagreed! not so different from the real world.
The parent still brings up some valid points. Remember how a few months after 9/11 the Department of Immigration (or whatever it's called) sent the valid work permits and visas to one of the Al Queda pilots of 9/11. And these were processed AFTER 9/11. So obviously there are major flaws in the system somewhere.
Yeah, in this remake the vehicles will be shot out from a giant Martian walkie-talkie instead of a cannon.
I guess I'm old fashioned, but I thought Citizen Kane was absolutely amazing. Even more so that despite being 50 years old, it's still every bit as relevent today as it was then.
Anyway, whether you believe him or not, keep in mind he's marketing his book. Any controversy he stirs up will increase his sales (aka 'The Passion') and give him more profit. I tend to believe his stance is about as biased as the White House press secretary. But it's still more data points on the graph, even if they might have larger error bars.
That might solve the problem, you get a page, then you check in with it via email or landline phone.