The original article discusses middle and high schools. I'm sure there are students capable of writing and multiplication by that stage, who'd enjoy the chance to learn a bit about, e.g. Adobe Premiere.
When I said "zero divergence" I was loosely referring to the fact that the contraction of it's covarient derivative vanishes. This, though, is surely local conservation of energy? Which is all I am claiming. The extra terms you have involving the connection coefficients do stop the "usual" divergence from vanishing, but that is hardly surprising - gravitation (i.e. curvature) influences the matter fields!
No, the GR field equations state that the stress-energy tensor is proportional to the Einstein curvature tensor - which has a divergence that is identically zero in any spacetime. Even with a cosmological constant different from zero, since the metric has zero divergence the conclusion still holds.
According to this article, Andrew Barron (Rice University) seems to think we could see this technology used in Formula One racing cars, as early as next season. Although he's probably being a little optimistic, something like a Formula One team would certainly have the sponsors to experiment with tech like this, and develop cheaper manufacturing processes (if possible).
Just a thought: there was a story recently on Slashdot mentioning (or rather, implying the existence of) potential
benefits of not driving the crocodile (large animal, top-tier predator) to extinction. It is speculative of me to say this, of course, but perhaps we actually have suffered in ways we can't even imagine, by driving certain species to extinction.
Maybe mammoth saliva, for example, is a sure-fire cure for male pattern baldness?:-)
Absolutely 100% right. Don't mislead children into thinking that you can become a top physicist/surgeon/athlete without putting in serious hours, and learning the art of self-discipline. We should be teaching them that the best rewards in life come from working extremely bloody hard, doing stuff that sometimes, just sometimes, you will hate.
Otherwise what will they do the first time they encounter a genuine challenge?
From tiny microbe, to basic animal, to dodo... d'oh!
Sorry, couldn't resist;-)
Serious point: humans are capable of altering their habitat quite rapidly. Random mutation and natural selection aren't necessarily able to keep up, and species which are indirectly useful to us (say, plankton) could be driven to extinction. You can't just say "well, tough luck little plankton, should've mutated faster" - because we could ultimately suffer.
FYI: I remember reading on BBC News (a few years ago) that there are around 50000 reported cases of women being raped in South Africa each year. I might not have the exact figure but it was definitely that order of magnitude.
South Africa has quite a problem with HIV (the South African Department of Health Study estimates that 29.5% of pregnant women were living with HIV in 2004 according to this site).
It could be fairly likely that rape cases provided a non-negligible contribution to the spread of HIV, at least in SA.
My intended definition of "superior" was for hunting, killing, and consuming (in whatever manner) of other animals.
Interesting... so the bacteria which break down our remains, when we die - they are superior to all of us, by that reasoning.
In relation to your last point (only helping a species if it is known to be useful to us): what species do you depend on? Just how well mapped out are the dependencies between species?
Someone should've told that to Stephen Hawkins before he did the awful "keep talking" ad for British Telecom:-)
Seriously though, I can't imagine what spin you could put on this to tempt the general public (let alone vegetarians) to eat this pseudofood... Probably just as well I'm not in marketing...
"With a single cell, you could theoretically produce the world's annual meat supply. And you could do it in a way that's better for the environment and human health. In the long term, this is a very feasible idea."
I'm afraid your wife will have to go without the meat substitute. Personally I would not see any problem with eating this stuff (despite being vegetarian), but.... reading the article doesn't exactly make your mouth water, does it?
Indeed! It would be interesting to have a follow-up study, and interview the cadets to find out why they made the choices they did (if they haven't done so already). Well, interesting to me anyway...;^)
Oops quoted totally the wrong part of the article - actually the cadets were merely instructed to visit a website:
In June 2004, more than 500 cadets at West Point received an email from Col. Robert Melville notifying them of a problem with their grade report and ordering them to click on a link to verify that the grades were correct. More than 80% of the students dutifully followed the instructions.
The article continues, to mention that the cadets could easily have been duped into downloading spyware or a trojan, but instead were presented with a "gotcha" message.
n the first phase, in March, nearly 10,000 employees received an email with the logo of the state's Office of Cyber Security and Critical Infrastructure Coordination. The note directed employees to a special "password checker" site. "You are required to check your password by clicking on the link below and entering your password and email address by close of business today."
Hence my comment about there being a dire need for education.
Of course, I use pine on Unix, so I feel quite comfortable opening up any e-mail. I know this doesn't make me bullet-proof, but so far nothing bad has ever hit me this way.
As you must appreciate, pine (or indeed any other software) won't protect you against a sufficiently clever social engineer. The best you can do, when asked for personal information, is to take steps to verify the identity of the requestor - if it's a name you recognise, call them via phone perhaps, or at least email them to ask for proof of some kind...
I think this exercise was kind of silly, "Look, these cadets in an ARMY SCHOOL will follow what a SUPERIOR tells them to do! OMG ROFL!!!!11"
It's not silly - I think it illustrates that army cadets are particularly vunerable to social engineering attacks, and therefore in dire need of education - i.e. they really need to understand that they should never hand out passwords etc. to someone via email (or telephone for that matter) just because they claim to be an officer/tech support worker.
Looking at the website, I don't think it's really intended to be used as a server - at least not primarily. It is, however, an amazingly cool little portable PC - powered over another PC's USB, steals the host's input/output devices - how cool is that! I'm quite tempted to buy one myself. Just a pity that it only has 64Mb onboard RAM....
Slashdot Mirror
The original article discusses middle and high schools. I'm sure there are students capable of writing and multiplication by that stage, who'd enjoy the chance to learn a bit about, e.g. Adobe Premiere.
There is nothing extra you can do with a computer on a schooldesk that you cannot do with books, pencil and paper.
Nonlinear digital video editing?
When I said "zero divergence" I was loosely referring to the fact that the contraction of it's covarient derivative vanishes. This, though, is surely local conservation of energy? Which is all I am claiming. The extra terms you have involving the connection coefficients do stop the "usual" divergence from vanishing, but that is hardly surprising - gravitation (i.e. curvature) influences the matter fields!
That would be cool - I suppose it would look a little like a soap bubble.
No, the GR field equations state that the stress-energy tensor is proportional to the Einstein curvature tensor - which has a divergence that is identically zero in any spacetime. Even with a cosmological constant different from zero, since the metric has zero divergence the conclusion still holds.
Even in GR, the stress-energy tensor has zero divergence.
According to this article, Andrew Barron (Rice University) seems to think we could see this technology used in Formula One racing cars, as early as next season. Although he's probably being a little optimistic, something like a Formula One team would certainly have the sponsors to experiment with tech like this, and develop cheaper manufacturing processes (if possible).
Just a thought: there was a story recently on Slashdot mentioning (or rather, implying the existence of) potential benefits of not driving the crocodile (large animal, top-tier predator) to extinction. It is speculative of me to say this, of course, but perhaps we actually have suffered in ways we can't even imagine, by driving certain species to extinction.
Maybe mammoth saliva, for example, is a sure-fire cure for male pattern baldness? :-)
Absolutely 100% right. Don't mislead children into thinking that you can become a top physicist/surgeon/athlete without putting in serious hours, and learning the art of self-discipline. We should be teaching them that the best rewards in life come from working extremely bloody hard, doing stuff that sometimes, just sometimes, you will hate. Otherwise what will they do the first time they encounter a genuine challenge?
From tiny microbe, to basic animal, to dodo... d'oh!
Sorry, couldn't resist ;-)
Serious point: humans are capable of altering their habitat quite rapidly. Random mutation and natural selection aren't necessarily able to keep up, and species which are indirectly useful to us (say, plankton) could be driven to extinction. You can't just say "well, tough luck little plankton, should've mutated faster" - because we could ultimately suffer.
FYI: I remember reading on BBC News (a few years ago) that there are around 50000 reported cases of women being raped in South Africa each year. I might not have the exact figure but it was definitely that order of magnitude.
South Africa has quite a problem with HIV (the South African Department of Health Study estimates that 29.5% of pregnant women were living with HIV in 2004 according to this site).
It could be fairly likely that rape cases provided a non-negligible contribution to the spread of HIV, at least in SA.
My intended definition of "superior" was for hunting, killing, and consuming (in whatever manner) of other animals.
Interesting... so the bacteria which break down our remains, when we die - they are superior to all of us, by that reasoning.
In relation to your last point (only helping a species if it is known to be useful to us): what species do you depend on? Just how well mapped out are the dependencies between species?
Well, you learn something every day.... :-) apologies to the professor.
Someone should've told that to Stephen Hawkins before he did the awful "keep talking" ad for British Telecom :-)
Seriously though, I can't imagine what spin you could put on this to tempt the general public (let alone vegetarians) to eat this pseudofood... Probably just as well I'm not in marketing...
"With a single cell, you could theoretically produce the world's annual meat supply. And you could do it in a way that's better for the environment and human health. In the long term, this is a very feasible idea."
I'm afraid your wife will have to go without the meat substitute. Personally I would not see any problem with eating this stuff (despite being vegetarian), but.... reading the article doesn't exactly make your mouth water, does it?
And therefore it's not just the cadets who need educating.
Indeed! It would be interesting to have a follow-up study, and interview the cadets to find out why they made the choices they did (if they haven't done so already). Well, interesting to me anyway... ;^)
Oops quoted totally the wrong part of the article - actually the cadets were merely instructed to visit a website:
In June 2004, more than 500 cadets at West Point received an email from Col. Robert Melville notifying them of a problem with their grade report and ordering them to click on a link to verify that the grades were correct. More than 80% of the students dutifully followed the instructions.
The article continues, to mention that the cadets could easily have been duped into downloading spyware or a trojan, but instead were presented with a "gotcha" message.
From the article:
n the first phase, in March, nearly 10,000 employees received an email with the logo of the state's Office of Cyber Security and Critical Infrastructure Coordination. The note directed employees to a special "password checker" site. "You are required to check your password by clicking on the link below and entering your password and email address by close of business today."
Hence my comment about there being a dire need for education.
Of course, I use pine on Unix, so I feel quite comfortable opening up any e-mail. I know this doesn't make me bullet-proof, but so far nothing bad has ever hit me this way.
As you must appreciate, pine (or indeed any other software) won't protect you against a sufficiently clever social engineer. The best you can do, when asked for personal information, is to take steps to verify the identity of the requestor - if it's a name you recognise, call them via phone perhaps, or at least email them to ask for proof of some kind...
I think this exercise was kind of silly, "Look, these cadets in an ARMY SCHOOL will follow what a SUPERIOR tells them to do! OMG ROFL!!!!11"
It's not silly - I think it illustrates that army cadets are particularly vunerable to social engineering attacks, and therefore in dire need of education - i.e. they really need to understand that they should never hand out passwords etc. to someone via email (or telephone for that matter) just because they claim to be an officer/tech support worker.
Yeah, true, but don't forget the 'cool' factor. Also, the Blackdog device boots in 2 seconds! That's almost as fast as a ZX Spectrum!
Looking at the website, I don't think it's really intended to be used as a server - at least not primarily. It is, however, an amazingly cool little portable PC - powered over another PC's USB, steals the host's input/output devices - how cool is that! I'm quite tempted to buy one myself. Just a pity that it only has 64Mb onboard RAM....
Um, you seem to have failed to pick up on the submitter's sense of irony here.... (this has happened several times in the comments on this story).
Oops my bad. Please substitute 10 for 100 and disregard the stuff in parentheses!