So the question is (and I don't know, I didn't study nuclear physics beyond A-level), are the significant computational problems associated with the development of nuclear weapons easy to parallelize, or do they require a real supercomputer [sgi.com]?
I believe the calculations needed are massive finite element calculations. And I would imagine that things happen quickly enough in a nuclear explosion that there's a lot of significant stuff going on over a time period much shorter than it takes for any change to move from one side of the simulated device to the other.
As an analogy, suppose you wanted to simulate a large number of gravitating bodies. You would break the problem up into sections. Even though each body acts on every other, bodies outside a certain distance can be treated by their average force. So you can simulate things near each other on the same node, and have the nodes talk to pass the information about the "average" field. It requires some communication between nodes, but a large amount of work can be done on an individual nodes.
Or for your gas example, if you broke the problem up into boxes, you would have to "hand off" a particle as it passed from one box to another, and perhaps pass off information about forces close to the box boundaries. But if a lot of stuff is happening in a single box (like, say, chemical reactions), you can still get a big benefit out of parallalization.
Also, if designing nuclear bombs is anything like designing microwave components, you would have several simulations going at the same time, to try different variations on one design. Or you would design several subparts and have them running at the same time.
In short, I think that the problem very much lends it self to parallel computing.
What? HF+nitric can be used as a silicon etch, but most HF is used for oxide patterning and removal. I don't think isotropic silicon etches are much used in CMOS (the bulk of the mass produced silicon.)
Also, HF is buffer with NH4, not acetic acid. Also Acetic acid is basically distilled white vinegar.
Many of these chemicals, particularly HF, are very nasty. When I was doing safety training for using the fabrication lab at Berkeley, the answers to half the questions were "Put down whatever you're doing and get the hell out of the lab." I still get nervous when I have to use it.
The best warning was for florine gas, which we used in an excimer laser. I was told "Don't worry, it'll either kill you or you'll be fine - it doesn't give you cancer or anything."
Significance? Well, the frequency of the power is a good indication of the load on the grid as a whole (the cycle slows down under heavy loads, and speeds up under lighter loads.) Voltage monitoring tells you about power consumption close to you.
Whether this is significant is a matter of taste, I guess. But wouldn't it be cool to keep track of the load on the power grid? I think so. Of course, my wife tells me I'm a nerd...
I like a faster computer for work. First, I do three dimensional finite element solves, which take lots of computing time. And the more computing power I have, the large the mesh size I want to use.
Also, I've been doing a lot of numerical calculations in python, because the time saved writing the code is much greater than the time spent waiting for it to execute. Nevertheless, knocking down a run time from 7 hours would still be really nice, even if I have it running on someone else's computer. Even the five minute solves that could be reduced to 1 minute would make a difference - because five minutes isn't enough time to do something else.
I like to think of it as a challenge. I just bought a new hard drive, and I can save all my photographs on them. (Not that I don't need to back up to CD-ROM...)
What to do with 10 times as much storage? I could start keeping home videos on there. Or store all the network traffic that comes on and off my computer indefinitely. Or keep track of the voltage waveform coming in off the power lines, and post processing it after a year to look for frequency shifts.
But this talk of "no-one but video pirates would need this" is silly. Just give it to me, I'll think of something.
No, but subsequent copies of the first copy are bit for bit perfect. So you get a tiny loss up front, then perfect copies from then on.
This they are worried about. That's why DAT recorders don't let you make a digital copy of an analog recording. (Which is one of the reasons they flopped so badly on the market.)
Not sure about your state, but my options suck. I'll still go out and vote for the lesser evil, but still, lets not kid anyone here. Until they can't take payola from soft money (or whatever they call it), they really don't care what I want once they are in office.
At least you have options. I live in D.C. We have no voting representation in either house of congress.
Now is the time for everyone who complains about congress and laws like this to go out and vote.
As a resident in D.C., I have no voting representation in either the house or the senate (our one delegate can vote in committee in the house - whoopie.)
IIRC, there are two ways a bankrupt company (or any company, for that matter) can be liquidated. Either the assets can be sold, or the company can be sold.
It seems that selling the assets does not allow you to get the licences. However, if someone buys the whole company, wouldn't the licences go over? Because the new entity subsumes the old, and is bound to all its obligations and contracts, which include the right to use the software.
If you think about Superman's enemies, there are several "evil genius" types - Lex Luthor, for example.
So what's the lesson - brawn beats brains? It certaintly was true on the playground as a kid, but hardly inspiring. I would want Batman to win (as in DK2), just because he's so much more of an engineer.
The LaGrande initiative will coexist with existing security initiatives such as Microsoft's Palladium to create a more secure computing environment, Otellini said. It will secure the physical pathways that transport data on a computer's motherboard, and will be available for both servers and desktops. The technology will take until at least next year to come to market, however, probably with the next generation of Intel's desktop Pentium processors.
Securing the physical pathways that transpoty data on a computer's motherboard. This will sure help me against those tiny little hackers inside my computer stealing my data!
Oh wait, you mean this is to protect the data against me?
Looks like we have about a year before this is built into the PC architecture. Plan your computer buying wisely.
When I was an engineer for a large company, I would dress up more than I would otherwise be inclined to because I would be telling technicians who were 20+ years older than me what to do. Not that they wouldn't have done it anyway, but as a sign of respect. I figured if they were going to have to take directions from some one young enough to be their child, the least I could do was to dress up a bit to show them a little respect.
Now, it's mostly my wife who insists I dress nicely. My coworkers (I work in a company of 10 people), don't really care that much.
In fact, let's expand on it: I'd like a bill passed that would let me slash people's tires if they speed on my street.
What's the difference? It's just me damaging someone else's property because I feel they are violating my rights. Having the government mediate in disputes is so inefficient.
Actually, 120 GHz will penetrate walls, to some extent.
Millimeter wave imaging can operate in this frequency, because there's an atmospheric window (read: longer range) around there, and because most non-conducting "solid" object appear translucent at that wavelength.
So we would expect some penetration through walls. Especially the cheap drywall they use where I work
Rain will reduce the range/bandwidth, but it should go through dust, smoke, L.A. fog, etc. pretty well.
It's amazing how two press reports on the same breakthrough claim it's significant for entirely different reasons.
The earlier press release talked, in a half assed way, about the performance benefits. This one talks, in a half assed way, about the reduced size.
Of course, this happens because whoever digests these things for us unwashed masses doesn't understand what the hell they're talking about.
And the gate length has much more to do with the performance, not the transistor density, as the transistor density is dominated by the via sizes and interconnect sizes.
No, this wouldn't work. The slingshot effect changes the energy of a small object near a large one in a frame of reference that is not comoving the large object - for example, a rubber ball bouncing off a brick wall does not change it's energy in the frame of reference relative to the wall, but if you bounce it off of a moving truck, the energy in ground frame of reference will change - but not in the truck frame of reference.
Because in SOME frame of reference, the energy of the object doesn't change, this type of elastic collision CANNOT move an object from a bound to an unbound orbit.
Calculations suggest it may have been captured earlier this year.
Any small object near the earth-moon system sees a gravitational potential that is static (in some frame of reference.) The object either has enough energy to not be bound to the system, or it does not. So how is the capture supposed to take place? An object can't be captured by simply wandering into the vicinity of the earth, it needs some way to change it's energy - such as a collision with another object, which seems unlikely - space is big, and things rarely collide up there.
Unless there is some secret space-mining project which is deliberatly intercepting space rocks and slowing them down enough to keep them bound so they can extract space juice out of them...
I'm sitting here, waiting for my simulation to finish, trying to have a normal day. I listened to "Classic Rock" on the way in instead of NPR. I drove over the bridge from which I saw a plume of smoke rising from the pentagon on September 12.
There is a real tension between people who feel it's important to comemorate the day, and people who feel that it serves no purpose.
So what is the point of remembering? An event like the terrorist attacks rips back the surface, and exposes the stuff going on underneath. Some of that stuff is very ugly, and some is very good. So we commemorate and remember to get that glimpse under the surface again.
Looking under the surface is supposed to push us forward, to give us some direction. For me that means listening to my two Muslim collegues, with whom I rarely talk about politics, about how their lives at home have changed. And telling them about how my life, as a jew, has changed. And telling them about the prejudice my father faced when he was growing up Jewish in America in the 30's and 40's, to let them know that things can change here, over time.
What I am proud of about America is that it is a place where a jew and a muslim can work together, a nd connect over living in a majority culture that is not ours.
What makes me ashamed about America is that there still are, and will always be, people who will blindly hate us.
So by commemorating, I hope to keep these two opposed visions in my mind, to remind me to push, in my own small way, to the correct one.
I looked at the picture, and couldn't figure out what was going on. Where are the drain and source contacts? Does the inversion layer form in the subtrate or in the fin?
I understand trying to make it simpler, but why remove all information that's meaningful? They might as well say "here's an electromicrograph that looks like a tree, and here's a glossy diagram with some pretty boxes and arrows, but no actual information."
Slashdot Mirror
I believe the calculations needed are massive finite element calculations. And I would imagine that things happen quickly enough in a nuclear explosion that there's a lot of significant stuff going on over a time period much shorter than it takes for any change to move from one side of the simulated device to the other.
As an analogy, suppose you wanted to simulate a large number of gravitating bodies. You would break the problem up into sections. Even though each body acts on every other, bodies outside a certain distance can be treated by their average force. So you can simulate things near each other on the same node, and have the nodes talk to pass the information about the "average" field. It requires some communication between nodes, but a large amount of work can be done on an individual nodes.
Or for your gas example, if you broke the problem up into boxes, you would have to "hand off" a particle as it passed from one box to another, and perhaps pass off information about forces close to the box boundaries. But if a lot of stuff is happening in a single box (like, say, chemical reactions), you can still get a big benefit out of parallalization.
Also, if designing nuclear bombs is anything like designing microwave components, you would have several simulations going at the same time, to try different variations on one design. Or you would design several subparts and have them running at the same time.
In short, I think that the problem very much lends it self to parallel computing.
Oh, wait. Nevermind.
Also, HF is buffer with NH4, not acetic acid. Also Acetic acid is basically distilled white vinegar.
Many of these chemicals, particularly HF, are very nasty. When I was doing safety training for using the fabrication lab at Berkeley, the answers to half the questions were "Put down whatever you're doing and get the hell out of the lab." I still get nervous when I have to use it.
The best warning was for florine gas, which we used in an excimer laser. I was told "Don't worry, it'll either kill you or you'll be fine - it doesn't give you cancer or anything."
Significance? Well, the frequency of the power is a good indication of the load on the grid as a whole (the cycle slows down under heavy loads, and speeds up under lighter loads.) Voltage monitoring tells you about power consumption close to you.
Whether this is significant is a matter of taste, I guess. But wouldn't it be cool to keep track of the load on the power grid? I think so. Of course, my wife tells me I'm a nerd...
Also, I've been doing a lot of numerical calculations in python, because the time saved writing the code is much greater than the time spent waiting for it to execute. Nevertheless, knocking down a run time from 7 hours would still be really nice, even if I have it running on someone else's computer. Even the five minute solves that could be reduced to 1 minute would make a difference - because five minutes isn't enough time to do something else.
What to do with 10 times as much storage? I could start keeping home videos on there. Or store all the network traffic that comes on and off my computer indefinitely. Or keep track of the voltage waveform coming in off the power lines, and post processing it after a year to look for frequency shifts.
But this talk of "no-one but video pirates would need this" is silly. Just give it to me, I'll think of something.
No, but subsequent copies of the first copy are bit for bit perfect. So you get a tiny loss up front, then perfect copies from then on.
This they are worried about. That's why DAT recorders don't let you make a digital copy of an analog recording. (Which is one of the reasons they flopped so badly on the market.)
Where is dogbert and his strap-on spines?
At least you have options. I live in D.C. We have no voting representation in either house of congress.
As a resident in D.C., I have no voting representation in either the house or the senate (our one delegate can vote in committee in the house - whoopie.)
So vote one for the technies for me!
Support Voting Rights for DC
A beam shined into the interior corner of a cube comes out in exactly the opposite direction. Send that beam right back atcha!
It seems that selling the assets does not allow you to get the licences. However, if someone buys the whole company, wouldn't the licences go over? Because the new entity subsumes the old, and is bound to all its obligations and contracts, which include the right to use the software.
So what's the lesson - brawn beats brains? It certaintly was true on the playground as a kid, but hardly inspiring. I would want Batman to win (as in DK2), just because he's so much more of an engineer.
Securing the physical pathways that transpoty data on a computer's motherboard. This will sure help me against those tiny little hackers inside my computer stealing my data!
Oh wait, you mean this is to protect the data against me? Looks like we have about a year before this is built into the PC architecture. Plan your computer buying wisely.
Bastards.
Now, it's mostly my wife who insists I dress nicely. My coworkers (I work in a company of 10 people), don't really care that much.
What's the difference? It's just me damaging someone else's property because I feel they are violating my rights. Having the government mediate in disputes is so inefficient.
I guess they want you to use the remaining time to bath?
Millimeter wave imaging can operate in this frequency, because there's an atmospheric window (read: longer range) around there, and because most non-conducting "solid" object appear translucent at that wavelength.
So we would expect some penetration through walls. Especially the cheap drywall they use where I work
Rain will reduce the range/bandwidth, but it should go through dust, smoke, L.A. fog, etc. pretty well.
The earlier press release talked, in a half assed way, about the performance benefits. This one talks, in a half assed way, about the reduced size.
Of course, this happens because whoever digests these things for us unwashed masses doesn't understand what the hell they're talking about.
And the gate length has much more to do with the performance, not the transistor density, as the transistor density is dominated by the via sizes and interconnect sizes.
Because in SOME frame of reference, the energy of the object doesn't change, this type of elastic collision CANNOT move an object from a bound to an unbound orbit.
Any small object near the earth-moon system sees a gravitational potential that is static (in some frame of reference.) The object either has enough energy to not be bound to the system, or it does not. So how is the capture supposed to take place? An object can't be captured by simply wandering into the vicinity of the earth, it needs some way to change it's energy - such as a collision with another object, which seems unlikely - space is big, and things rarely collide up there.
Unless there is some secret space-mining project which is deliberatly intercepting space rocks and slowing them down enough to keep them bound so they can extract space juice out of them...
There is a real tension between people who feel it's important to comemorate the day, and people who feel that it serves no purpose.
So what is the point of remembering? An event like the terrorist attacks rips back the surface, and exposes the stuff going on underneath. Some of that stuff is very ugly, and some is very good. So we commemorate and remember to get that glimpse under the surface again.
Looking under the surface is supposed to push us forward, to give us some direction. For me that means listening to my two Muslim collegues, with whom I rarely talk about politics, about how their lives at home have changed. And telling them about how my life, as a jew, has changed. And telling them about the prejudice my father faced when he was growing up Jewish in America in the 30's and 40's, to let them know that things can change here, over time.
What I am proud of about America is that it is a place where a jew and a muslim can work together, a nd connect over living in a majority culture that is not ours.
What makes me ashamed about America is that there still are, and will always be, people who will blindly hate us.
So by commemorating, I hope to keep these two opposed visions in my mind, to remind me to push, in my own small way, to the correct one.
I understand trying to make it simpler, but why remove all information that's meaningful? They might as well say "here's an electromicrograph that looks like a tree, and here's a glossy diagram with some pretty boxes and arrows, but no actual information."
Harrumph!