So I'm guessing this public version of the tool used to operate the rover lacks some capabilities, like the ability to operate the rover?
Actually Science Activity Planner (the mission version of Maestro) is used to generate plans which are then turned into the actual sequences through various software packages and some human judgement calls. Even the full version cannot control the rover.
But yes, the public activity dictionary (which determines the structure of the plans) is significantly different from the mission version.
Cheers,
Justin Wick
Science Activity Planner Support Staff
Mars Exploration Rovers
I was hoping we finally had vacuum tubes grown on a chip. Besides building Eniac on a chip (but without the power bill and air conditioning problems) we could have every vacuum tube guitar amp ever made on a chip - just need a clean power amp after it.
I do not believe that the characteristics of vacuum tubes that make them good for audio extend nicely into the micro-realm.
It's much more likely that their different effects could be simulated by a properly adjustable tube, to sound like whatever you wanted.
It's very interesting... Many many people at JPL knew all about this, however the information was not known to be secret until yesterday, when it was announced that there'd be a bit of "unvieling" of the disk.
I"m surprised news didn't get out to the public before.
Cheers,
Justin Wick
Science Activty Planner Support Staff
Mars Exploration Rovers
One interesting mystery is the presence of dark patches that look like mud near the rover - they are clearly visible at the bottom the larger 8MB version of the photo on the nasa site. They are most likely formed by the airbags, but have an unusual dark appearance that really looks like wet ground.. nobody seems to know why they'd look that way from what I've read so far.
I was talking to one of the geologists during my shift yesterday and I was told that Martian dust has a higher albedo than the rest of the rocks, etc, on mars. This means anywhere that ther eis dust, things look brighter. Ergo, remove the dust and it will appear much darker.
If you look at orbital THEMIS data, you can see all kinds of dark streaks near the landing site caused by dustdevils (mostly formed inside craters).
Disclaimer: I'm a software engineer, not a geologist, but I work for MER.
Cheers,
Justin Wick
Science Activity Planner Support Staff
Mars Exploration Rovers
I've loaded Maestro and tried out "Go to ISIL test facility" with success, but when I go to "Go to "Spirit's Landing Site", I get "you have not yet loaded data from Spirit, return to Maestro website to download...". What do I do now? Where do I get the data?
There has not been a sprit release yet. There is one coming in a few days. You can't go to Spirit's Landing Site yet.
Cheers,
Justin Wick
Science Activity Planner / Maestro Support Staff
Mars Exploration Rovers
But, like any well thought out mission, the website had a backup plan, and now they have a minimal plain text home page showing, with just links to the download files. Dunno if they had this already mapped out as a contingency for/., or if they adapted on the fly, either way, shows they are on top of the situation...
That was totally a decision made on the fly... the freecaching, the text only page, and the bittorrents were all added as soon as the webserver started flaming at the ports:)
Should be back up to something presentable soon.
Cheers,
Justin Wick
Science Activity Planner / Maestro Support Staff
Mars Exploration Rovers
When creating the activity plans, is it miles or kilometers? Wouldn't want to crash into anything
All distances are in meters. (UYnless marked otherwise). All angles are externally in degrees, internally in radians.
Rotations are quaternions I believe.
Cheers
Justin
Science Activity Planner / Maestro Support Staff
Mars Exploration Rovers
All the same there's only one thing worse than a sore loser and that's an ungracious winner. There's really no need to go strutting and preening and engaging in dominance poses about it. It shows quite a bit more class to just win and then be decent about it.
To me, this wasn't a victory for the United States, this is a victory for all of mankind! We would be foolish not to aknowlege that much of the technology used on this mission came from other countries (and the ideas for them). We may not always see eye to eye, and we may fight ourselves constantly but we are all in this together folks. I will tell you that no one I"ve met here was anything but sympathetic towards the Beagle guys, and we really hope they re-establish contact (though it seems unlikely). Thanks to everyone around that world that contributed to this tremendous success!
Cheers,
Justin Wick
Science Activity Planner Support Staff
Mars Exploration Rovers
What a poor design! They have to update the software in order to get new images? That's got to be the dumbest thing I've heard in a long time. Did they forget that the Internet exists where you can update images and indexes automatically? Sheesh.
Disclaimer: I'm a junior member of the Maestro Development team, however most of my work was on the mission version (SAP), not the public version.
The original specifications for Maestro (originally called WITS) contained an automatic updating client called MECS (Multimission Encrypted Communications System). I worked heavily on this the summer of 2002, and it was really great. It was going to work a bit like CVS in that it used deltas to transfer changes between versions of files, and had intelligent merging of XML content, etc. However due to funding constraints, the plug was pulled on MECS so there are no automatic updates.
There is a scientist version of SAP for use on personal computers that uses something called SAP-SYNC that automatically updates everything by comparing what's on client with server ahnd using LFTP, however it was theorized that the load on JPL's servers would be far to great to do that for all of our fans out there.
It was decided because of the massive budget cuts, little funding, and of course the fact that our staff has dropped down to all of three people to keep things simple. Doing things this way makes it possible to bittorrent things (I actually told them to bittorrent this for slashdotting about a year ago, however things have been so hectic here I"m not surprised they didn't!)
If you're interested in the design of MECS and how it was supposed to function, check out this paper.
As for the people complaining about the design, we don't really like it either! Write your congressman, get NASA outreach more funding, and we'll have things to really engage the population!
Cheers,
Justin Wick
Science Activity Planner Support Staff
Mars Exploration Rovers
Well, having been in building 264 at JPL (the MER mission operations building) I must say it was an exciting experience... Everyone was waiting really tense, jumping once or twice at some of the annoucements that sounded bad at first... six minutes from landing to signal confirmation, the longest 6 in my life!
When we got the signal, it was truely spectacular, everyone so excited, clapping, standing and hugging each other with vigorous congradulations. I was fortunate enough to be able to congradulate some of the higher ups (PI Steve Squyres, whom I work for, and Science Manager John Callas).
On behalf of all of us on MER, I'd like to thank everyone that's supported this mission, especially those slashdotters that have vigorously defended the purpose and existance of mars. What we are doing is hard, but not impossible, and we will continue to try until we prevail.
Today we had what I hope was the first of many victories on mars. We should be getting the first image back in a few minutes from the next odyssey pass.
BTW, I'm not sure what the press releases said, but we were very fortunate that the lander landed base petal down, which should speed up deployment significantly as there is no need for the actuators to push against the weight of the rover.
As I said earlier tonight, tonight went so well that it was as if we won the lottery, and by that I mean not just us at JPL but everyone on earth that will benefit from the knowlege we acquire. Congradulations all!
Cheers,
Justin Wick
Science Activity Planner Support Staff
Mars Exploration Rovers
My Alma Mater, Cornell University, has almost finished construction of Duffield Hall.
It is a dual nanotech/biotech fascility (it's quite large and rather high-tech looking). It's actually quite impressive to have nanotech and biotech in the same building (as many biotech componets, such as saline solvents, damage nanotech devices in moderate proximity) and has state-of-the-art cleanrooms and filtering.
It's been in the works all 4 of my years here at Cornell and I'm really excited about going inside it next year!
For the last 25 years Cornell has done a ton of research in nanotechnology (the National Science Foundation research lab is at Cornell). There's even a freshmen class in nanotechnolgoy where the class fabricates ultrasmall devices.
Cornell is shifting quite a bit of emphasis onto biotechnology, providing it as an option for engineering majors, and even starting to require biology classes for all engineers (I escaped that, not sure if that was a good thing or a bad thing).
Props to Georgia Tech, glad to see there's some great universities out there joining us in the search for new and exciting things to do with atoms:)
I'm not saying that I think this thing is dumb, I just don't see how they can call this a commercial application. Guiding missles isn't something I shop for at Walmart. It's surely a useful research tool (like I previously mentioned) and apparently useful for military applications, but I'm still left wondering what type of commercial application this thing would serve.
If you'd like to read a great article that explains this, check out:
EE Times Story from 2001.
It mentions this is very useful for "fast Fourier transforms/inverse fast Fourier transforms (FFTs)/(IFFTs), discrete cosine transform (DCT), discrete Fourier transform (DFT), compression, vector-matrix multiplication, equalization and correlation". ALl of these are very useful for processing communications signals such as in cell phones or high-quality recievers (HDTV in rural areas?).
It also mentions that the optical light is modulated at 10 GhZ frame rate (but remember, this is quite parallel processing) and no ordinary computer we have today could possibly crunch 10 billion FFTs in a second. So the terrahertz number is mostly them just stacking it against existing computers.
They used to use regular electronic circuits to solve differential equations and similar problems too. They didn't get an exact solution, but they got a usable value. I think that's what you're talking about here.
You're talking about old analog electronic computers... yeah those weren't very precise (one of the reasons they are no longer used).
What I'm talking about is a little different. Those electronic ciruits would solve differential equations in the time domain (requiring a bit of time to compute) whereas these optical processors process information in the frequency domain (almost instantly, the bottlneck is as you say how fast they can moduate the light from an electronic signal).
Frequency domain computing is fundamentally different from the time domain computing in that in time domain analog computers, tiny errors accumulate very rapidly. For instance, an operational amplifier that is used to perform an integration will have a small bias current which will slowly charge the integrating capactor(s), requiring the integration to be rezeroed every so often (at least every few seconds, if not many times a second). In frequency domain computation, the error is not accumulative like that. There is error, and it does add up, but its pretty much orthogonal (the error is spread throughout the frequency space, rather than adding up towards the end of the time space in a time domain computer).
A really great article I found (this is the one I originally read back in 2001) is here. Anyone interested in the more technical side of the processor should read it. It explains why the processing is so fast (because it's essentially parallel rather than serial, along with being based on photons rather than electrons).
That's where I got most of my information from, along with my optics and mathematical physics classes:)
Cheers,
Justin
Disclaimer: I'm still a semester away from my BS in physics
For real, what's the point of 8 trillion operations per second when there's no existing memory to support it (of which I am aware)? So this chip runs REALLY REALLY FAST on code that's REALLY REALLY SMALL, and otherwise it's bottlenecked by the memory bus and memory speeds.
I'm not quite sure you understand what this processor is, and how it works. This is *NOT* like a Pentium with a faster clockspeed. This is a signal processing chip which, rather than really executing code, uses a series of optical filters to do massively expensive mathematical operations. This has the following set of properties:
Operations in parallel on massive amounts of data. This means it could have a parallel bus of some sort, which could considerably increase the throughput of the system.
I believe the chip is equivilent to a terrahertz processor, but doesn't really operate that fast. It just happens to do calculations in one step that take thousands to millions of steps in normal processors.
Many real time applicatoins merely need a reduction in latency, not an increase in throughput. If you have a missile guidance system (yes, people have been working on using this for that purpose) you want to get the analysis of incoming sensor data done as quick as possible for lightning fast reaction times. Very imprtant when your software either functions correctly and on time, or the hardware is destroyed.
This type of technology could process analog electronic signals, which have a much higher throughput than the fastest digital signal bus.
The original poster was right, this IS the future, at least for now:)
Cheers,
Justin
Disclaimer: I'm one semester away from my bachelors in Physics
Interstingly, optical processors aren't faster because light is faster than electricity. They are faster because they have much faster rise and fall times between digital on and digital off.
While your statement may indeed be correct, that is not why this chip is faster. The reason is that they are doing analog signal processing using the physics of various optical elements to perform computationally intensive mathematics.
Think of it this way: We can use large, expensive mathematical operations to simulate optical components, which means we can also do the reverse - using optical components to perform the expensive mathematical operations.
I read about this about 2 years ago, and it was really quite fascinating to me. It turns out that with a simple lense, you can compute a fourier transform just by focussing the light (it doesn't focus down to an infinitesimally small point).
I managed to find an article about this, hopefully it should be apparent why this chip doesn't run quake: Check it out here.
They are certainly not the only people doing this. I've seen plenty of references of this being used in missile guidance systems (turns out a simple fourier transform trick can be used to track objects in a camera). Someone I met while working at the Jet Propulsion Lab was working on this Optical Signal Processors. They prove to be very big in the next 10 years.
Unfortunately, there was no information about protocols, encoding, or error correction schemes..
Well, I happen to work on MER as a software engineer, and I was consulted for an article on the Athena web site (athena.cornell.edu) on the communications system, but I'm certainly no expert.
The X-Band system uses Binary Phase Shift Keying, which is a lot like the modulation used in QPSK (Used sometimes to send data upstream over cable as it is more resistant to noise) and 64QAM (Used to send data downstream over cable, as it is more efficient and noise is not an issue).
There's a ton of papers out there on this sort of stuff... if you wish to get nitty-gritty with dsn, I reccommend some of the articles on this page
There's obviously a lot more to it... I know DSN uses MASERS for certain things, but not sure about this mission. To see how odyssey uses the DSN, read this pdf.
And if you wonder exactly what I do, check out this article.l
The idea that your RFID tag can be tracked and monitored over a great distance is complete nonsense. The guy who submitted this needs to get a refund on that tinfoil hat of his.
Nothing like a really dumb conspiracy theory to hold back progress. People, these tags are readable up to a few inches. Maybe a foot at most. They are nothing but glorified bar codes. Good for tracking inventory at most.
The RF radiation is hardly "undetectable" more than a foot away. While the range of inductive systems is definitely more limited than radiative systems, there will always be a radiative component. Stock detectors (which do not *WANT* to pick up all RFIDs in the general vecinity, only the ones directly there) may be limited to the distance, however, the radiation continues out until it's absorbed by something (the limit is line-of-sight and signal-to-noise).
The people the Tinfoil Hat Wearers are usually afraid of (government, researchers, etc) have access to technologies that are incredibly successful in picking up tiny RF signatures (whether it be a distant galaxy or an enemy transmission). It may not be cheap, but don't say it's "nonsense".
Granted there may be easier ways to track someone than by their RFIDs but as time goes on the price of tracking equipment will continue to decrease until it's commerically available to those who want to make the investment. As somone else on slashdot mentioned, it could be used by muggers to figure out an estimated take from individuals walking down a sidewalk (only a meter away or so).
No I'm not paranoid and dont' even care if the government is tracking me, but it's technically possible and for some people this is going to be a problem.
Strange, the first time I tried the "broken" link, it gave "internal server error" but now it seems to work (even though it's the same link). Maybe the error was unrelated (I know that unix systems will usually parse paths with//'s in them. Netcraft says they are running linux and apache so maybe it's just unrelated.
The processor we believe, sits in the LGA 775 pin socket, and above it is a very thin heatsink. But, according to sources close to the firm's plans, another permeable heatsink can sit between this and another microprocessor module, giving a stackable design.
Yes, I saw that in the article, and it's pretty much the only way you *can* do it, to have something separating the chips. The question is, how can they get this to work? I mean, there's limits to how fast heat can be spread away by something like this (based on the heat conduction coefficient of the material you are using) and the latency between chips increases linearly as you increase the thickness of the separator... We can barely keep faster chips right now cool with enormous heatsinks... this seems far more ambitious.
Also remember ohmic heating is proportional to the square of the clock speed (yes, it goes down by a factor as you get the components smaller, but you see where this is heading). IT will be a long while till Intel chips don't put out a ton of heat (when they start using something like spintronics or photonics). There's simply too much current to dissapate.
Stackable designs sound really cool in the sense that you can cut latency between processors (for things like cache coherence) to rediculously small levels, but what about cooling? Cooling ability is roughly proportional to surface area, and two stacked chips will make twice as much heat but have almost the same surface area as only one (as two sides cancel out). This has to be a problem.
No this is not a troll. I honestly wonder how they expect to accomplish this.
Slashdot Mirror
So I'm guessing this public version of the tool used to operate the rover lacks some capabilities, like the ability to operate the rover?
Actually Science Activity Planner (the mission version of Maestro) is used to generate plans which are then turned into the actual sequences through various software packages and some human judgement calls. Even the full version cannot control the rover.
But yes, the public activity dictionary (which determines the structure of the plans) is significantly different from the mission version.
Cheers,
Justin Wick
Science Activity Planner Support Staff
Mars Exploration Rovers
I was hoping we finally had vacuum tubes grown on a chip. Besides building Eniac on a chip (but without the power bill and air conditioning problems) we could have every vacuum tube guitar amp ever made on a chip - just need a clean power amp after it.
I do not believe that the characteristics of vacuum tubes that make them good for audio extend nicely into the micro-realm.
It's much more likely that their different effects could be simulated by a properly adjustable tube, to sound like whatever you wanted.
Cheers,
Justin
It's very interesting... Many many people at JPL knew all about this, however the information was not known to be secret until yesterday, when it was announced that there'd be a bit of "unvieling" of the disk.
I"m surprised news didn't get out to the public before.
Cheers,
Justin Wick
Science Activty Planner Support Staff
Mars Exploration Rovers
One interesting mystery is the presence of dark patches that look like mud near the rover - they are clearly visible at the bottom the larger 8MB version of the photo on the nasa site. They are most likely formed by the airbags, but have an unusual dark appearance that really looks like wet ground.. nobody seems to know why they'd look that way from what I've read so far.
I was talking to one of the geologists during my shift yesterday and I was told that Martian dust has a higher albedo than the rest of the rocks, etc, on mars. This means anywhere that ther eis dust, things look brighter. Ergo, remove the dust and it will appear much darker.
If you look at orbital THEMIS data, you can see all kinds of dark streaks near the landing site caused by dustdevils (mostly formed inside craters).
Disclaimer: I'm a software engineer, not a geologist, but I work for MER.
Cheers,
Justin Wick
Science Activity Planner Support Staff
Mars Exploration Rovers
I've loaded Maestro and tried out "Go to ISIL test facility" with success, but when I go to "Go to "Spirit's Landing Site", I get "you have not yet loaded data from Spirit, return to Maestro website to download ...". What do I do now? Where do I get the data?
There has not been a sprit release yet. There is one coming in a few days. You can't go to Spirit's Landing Site yet.
Cheers,
Justin Wick
Science Activity Planner / Maestro Support Staff
Mars Exploration Rovers
But, like any well thought out mission, the website had a backup plan, and now they have a minimal plain text home page showing, with just links to the download files. Dunno if they had this already mapped out as a contingency for /., or if they adapted on the fly, either way, shows they are on top of the situation...
:)
That was totally a decision made on the fly... the freecaching, the text only page, and the bittorrents were all added as soon as the webserver started flaming at the ports
Should be back up to something presentable soon.
Cheers,
Justin Wick
Science Activity Planner / Maestro Support Staff
Mars Exploration Rovers
PC LOAD LETTER, wtf does that mean? :)
When creating the activity plans, is it miles or kilometers? Wouldn't want to crash into anything All distances are in meters. (UYnless marked otherwise). All angles are externally in degrees, internally in radians.
Rotations are quaternions I believe.
Cheers
Justin
Science Activity Planner / Maestro Support Staff
Mars Exploration Rovers
All the same there's only one thing worse than a sore loser and that's an ungracious winner. There's really no need to go strutting and preening and engaging in dominance poses about it. It shows quite a bit more class to just win and then be decent about it. To me, this wasn't a victory for the United States, this is a victory for all of mankind! We would be foolish not to aknowlege that much of the technology used on this mission came from other countries (and the ideas for them). We may not always see eye to eye, and we may fight ourselves constantly but we are all in this together folks. I will tell you that no one I"ve met here was anything but sympathetic towards the Beagle guys, and we really hope they re-establish contact (though it seems unlikely). Thanks to everyone around that world that contributed to this tremendous success!
Cheers,
Justin Wick
Science Activity Planner Support Staff
Mars Exploration Rovers
Thanks. I have always been a staunch defender of the existence of Mars.
:)
I'm not supposed to tell you this, but it's a government conspiracy!
Actually I woke up at 3:00 AM PST so... you get the idea
What a poor design! They have to update the software in order to get new images? That's got to be the dumbest thing I've heard in a long time. Did they forget that the Internet exists where you can update images and indexes automatically? Sheesh.
Disclaimer: I'm a junior member of the Maestro Development team, however most of my work was on the mission version (SAP), not the public version.
The original specifications for Maestro (originally called WITS) contained an automatic updating client called MECS (Multimission Encrypted Communications System). I worked heavily on this the summer of 2002, and it was really great. It was going to work a bit like CVS in that it used deltas to transfer changes between versions of files, and had intelligent merging of XML content, etc. However due to funding constraints, the plug was pulled on MECS so there are no automatic updates.
There is a scientist version of SAP for use on personal computers that uses something called SAP-SYNC that automatically updates everything by comparing what's on client with server ahnd using LFTP, however it was theorized that the load on JPL's servers would be far to great to do that for all of our fans out there.
It was decided because of the massive budget cuts, little funding, and of course the fact that our staff has dropped down to all of three people to keep things simple. Doing things this way makes it possible to bittorrent things (I actually told them to bittorrent this for slashdotting about a year ago, however things have been so hectic here I"m not surprised they didn't!)
If you're interested in the design of MECS and how it was supposed to function, check out this paper.
As for the people complaining about the design, we don't really like it either! Write your congressman, get NASA outreach more funding, and we'll have things to really engage the population!
Cheers,
Justin Wick
Science Activity Planner Support Staff
Mars Exploration Rovers
Well, having been in building 264 at JPL (the MER mission operations building) I must say it was an exciting experience... Everyone was waiting really tense, jumping once or twice at some of the annoucements that sounded bad at first... six minutes from landing to signal confirmation, the longest 6 in my life!
When we got the signal, it was truely spectacular, everyone so excited, clapping, standing and hugging each other with vigorous congradulations. I was fortunate enough to be able to congradulate some of the higher ups (PI Steve Squyres, whom I work for, and Science Manager John Callas).
On behalf of all of us on MER, I'd like to thank everyone that's supported this mission, especially those slashdotters that have vigorously defended the purpose and existance of mars. What we are doing is hard, but not impossible, and we will continue to try until we prevail.
Today we had what I hope was the first of many victories on mars. We should be getting the first image back in a few minutes from the next odyssey pass.
BTW, I'm not sure what the press releases said, but we were very fortunate that the lander landed base petal down, which should speed up deployment significantly as there is no need for the actuators to push against the weight of the rover.
As I said earlier tonight, tonight went so well that it was as if we won the lottery, and by that I mean not just us at JPL but everyone on earth that will benefit from the knowlege we acquire. Congradulations all!
Cheers,
Justin Wick
Science Activity Planner Support Staff
Mars Exploration Rovers
"Where are they going to get the nano-grad students to work in it?"
:)
They'll get them from The Shire, of course.
That failing there's always Japan...
*ducks*
My Alma Mater, Cornell University, has almost finished construction of Duffield Hall.
:)
It is a dual nanotech/biotech fascility (it's quite large and rather high-tech looking). It's actually quite impressive to have nanotech and biotech in the same building (as many biotech componets, such as saline solvents, damage nanotech devices in moderate proximity) and has state-of-the-art cleanrooms and filtering.
It's been in the works all 4 of my years here at Cornell and I'm really excited about going inside it next year!
For the last 25 years Cornell has done a ton of research in nanotechnology (the National Science Foundation research lab is at Cornell). There's even a freshmen class in nanotechnolgoy where the class fabricates ultrasmall devices.
Cornell is shifting quite a bit of emphasis onto biotechnology, providing it as an option for engineering majors, and even starting to require biology classes for all engineers (I escaped that, not sure if that was a good thing or a bad thing).
Props to Georgia Tech, glad to see there's some great universities out there joining us in the search for new and exciting things to do with atoms
Justin
I'm not saying that I think this thing is dumb, I just don't see how they can call this a commercial application. Guiding missles isn't something I shop for at Walmart. It's surely a useful research tool (like I previously mentioned) and apparently useful for military applications, but I'm still left wondering what type of commercial application this thing would serve. If you'd like to read a great article that explains this, check out: EE Times Story from 2001.
It mentions this is very useful for "fast Fourier transforms/inverse fast Fourier transforms (FFTs)/(IFFTs), discrete cosine transform (DCT), discrete Fourier transform (DFT), compression, vector-matrix multiplication, equalization and correlation". ALl of these are very useful for processing communications signals such as in cell phones or high-quality recievers (HDTV in rural areas?).
It also mentions that the optical light is modulated at 10 GhZ frame rate (but remember, this is quite parallel processing) and no ordinary computer we have today could possibly crunch 10 billion FFTs in a second. So the terrahertz number is mostly them just stacking it against existing computers.
Cheers,
Justin
They used to use regular electronic circuits to solve differential equations and similar problems too. They didn't get an exact solution, but they got a usable value. I think that's what you're talking about here.
:)
You're talking about old analog electronic computers... yeah those weren't very precise (one of the reasons they are no longer used).
What I'm talking about is a little different. Those electronic ciruits would solve differential equations in the time domain (requiring a bit of time to compute) whereas these optical processors process information in the frequency domain (almost instantly, the bottlneck is as you say how fast they can moduate the light from an electronic signal).
Frequency domain computing is fundamentally different from the time domain computing in that in time domain analog computers, tiny errors accumulate very rapidly. For instance, an operational amplifier that is used to perform an integration will have a small bias current which will slowly charge the integrating capactor(s), requiring the integration to be rezeroed every so often (at least every few seconds, if not many times a second). In frequency domain computation, the error is not accumulative like that. There is error, and it does add up, but its pretty much orthogonal (the error is spread throughout the frequency space, rather than adding up towards the end of the time space in a time domain computer).
A really great article I found (this is the one I originally read back in 2001) is here. Anyone interested in the more technical side of the processor should read it. It explains why the processing is so fast (because it's essentially parallel rather than serial, along with being based on photons rather than electrons).
That's where I got most of my information from, along with my optics and mathematical physics classes
Cheers,
Justin
Disclaimer: I'm still a semester away from my BS in physics
I'm not quite sure you understand what this processor is, and how it works. This is *NOT* like a Pentium with a faster clockspeed. This is a signal processing chip which, rather than really executing code, uses a series of optical filters to do massively expensive mathematical operations. This has the following set of properties:
The original poster was right, this IS the future, at least for now
Cheers,
Justin
Disclaimer: I'm one semester away from my bachelors in Physics
Interstingly, optical processors aren't faster because light is faster than electricity. They are faster because they have much faster rise and fall times between digital on and digital off.
While your statement may indeed be correct, that is not why this chip is faster. The reason is that they are doing analog signal processing using the physics of various optical elements to perform computationally intensive mathematics.
Think of it this way: We can use large, expensive mathematical operations to simulate optical components, which means we can also do the reverse - using optical components to perform the expensive mathematical operations.
I read about this about 2 years ago, and it was really quite fascinating to me. It turns out that with a simple lense, you can compute a fourier transform just by focussing the light (it doesn't focus down to an infinitesimally small point).
I managed to find an article about this, hopefully it should be apparent why this chip doesn't run quake:
Check it out here.
They are certainly not the only people doing this. I've seen plenty of references of this being used in missile guidance systems (turns out a simple fourier transform trick can be used to track objects in a camera). Someone I met while working at the Jet Propulsion Lab was working on this Optical Signal Processors. They prove to be very big in the next 10 years.
Cheers,
Justin
Unfortunately, there was no information about protocols, encoding, or error correction schemes..
Well, I happen to work on MER as a software engineer, and I was consulted for an article on the Athena web site (athena.cornell.edu) on the communications system, but I'm certainly no expert.
The X-Band system uses Binary Phase Shift Keying, which is a lot like the modulation used in QPSK (Used sometimes to send data upstream over cable as it is more resistant to noise) and 64QAM (Used to send data downstream over cable, as it is more efficient and noise is not an issue).
There's a ton of papers out there on this sort of stuff... if you wish to get nitty-gritty with dsn, I reccommend some of the articles on this page
There's obviously a lot more to it... I know DSN uses MASERS for certain things, but not sure about this mission. To see how odyssey uses the DSN, read this pdf.
And if you wonder exactly what I do, check out this article.l
Cheers, Justin
The idea that your RFID tag can be tracked and monitored over a great distance is complete nonsense. The guy who submitted this needs to get a refund on that tinfoil hat of his. Nothing like a really dumb conspiracy theory to hold back progress. People, these tags are readable up to a few inches. Maybe a foot at most. They are nothing but glorified bar codes. Good for tracking inventory at most.
The RF radiation is hardly "undetectable" more than a foot away. While the range of inductive systems is definitely more limited than radiative systems, there will always be a radiative component. Stock detectors (which do not *WANT* to pick up all RFIDs in the general vecinity, only the ones directly there) may be limited to the distance, however, the radiation continues out until it's absorbed by something (the limit is line-of-sight and signal-to-noise).
The people the Tinfoil Hat Wearers are usually afraid of (government, researchers, etc) have access to technologies that are incredibly successful in picking up tiny RF signatures (whether it be a distant galaxy or an enemy transmission). It may not be cheap, but don't say it's "nonsense".
Granted there may be easier ways to track someone than by their RFIDs but as time goes on the price of tracking equipment will continue to decrease until it's commerically available to those who want to make the investment. As somone else on slashdot mentioned, it could be used by muggers to figure out an estimated take from individuals walking down a sidewalk (only a meter away or so).
No I'm not paranoid and dont' even care if the government is tracking me, but it's technically possible and for some people this is going to be a problem.
Strange, the first time I tried the "broken" link, it gave "internal server error" but now it seems to work (even though it's the same link). Maybe the error was unrelated (I know that unix systems will usually parse paths with //'s in them. Netcraft says they are running linux and apache so maybe it's just unrelated.
Sorry guys.
I emailed the on-duty editor but it looks like they didn't catch it. There's an extra / in the link. Try this one:
http://www.oreillynet.com/pub/wlg/3812
Cheers,
Justin
Look, if you're going to be insulting, at least do so under your registered name. There's a reason it's called Anonymous Coward.
I honestly couldn't see the post that was posted 10 seconds before mine... I'm still not sure why the mods think my post should be at -1.
The processor we believe, sits in the LGA 775 pin socket, and above it is a very thin heatsink. But, according to sources close to the firm's plans, another permeable heatsink can sit between this and another microprocessor module, giving a stackable design.
Yes, I saw that in the article, and it's pretty much the only way you *can* do it, to have something separating the chips. The question is, how can they get this to work? I mean, there's limits to how fast heat can be spread away by something like this (based on the heat conduction coefficient of the material you are using) and the latency between chips increases linearly as you increase the thickness of the separator... We can barely keep faster chips right now cool with enormous heatsinks... this seems far more ambitious.
Also remember ohmic heating is proportional to the square of the clock speed (yes, it goes down by a factor as you get the components smaller, but you see where this is heading). IT will be a long while till Intel chips don't put out a ton of heat (when they start using something like spintronics or photonics). There's simply too much current to dissapate.
Cheers,
Justin
Stackable designs sound really cool in the sense that you can cut latency between processors (for things like cache coherence) to rediculously small levels, but what about cooling? Cooling ability is roughly proportional to surface area, and two stacked chips will make twice as much heat but have almost the same surface area as only one (as two sides cancel out). This has to be a problem.
No this is not a troll. I honestly wonder how they expect to accomplish this.
Anyone know?
Cheers,
Justin