I think the idea is to use hydrogen as an energy storage alternative to batteries. The problem with batteries is that the basically suck. Sure, they suck a lot less than they used to but they are heavy, expensive, and take a long time to charge.
The (over-)simplified system with batteries is:
power source -> electricity distribution network -> charge battery -> power motor
The charge battery step is the long one. Even though EVs with a few hundred miles of range will work very well for the vast majority of urban travelers, the long charge time prevents the use of EVs in any long distance use cases.
Using hydrogen changes the (again, over-)simplified system to:
power source -> hydrogen generation -> fuel distribution network -> fill H2 tank -> fuel cell -> power motor
This system has its problems, to be sure. However, it replaces the "charge battery" step with "fill H2 tank" which can operate similarly to filling gasoline tanks today. It does require new infrastructure development, but then long distance travelers, transportation drivers, delivery drivers, etc. can go about their day and re-fill the H2 tanks when necessary.
Is it worth it? I don't know. But it is an other avenue to solving addressing the limitations with batteries.
Many statements from the summary directly contradict my personal experience. The summary states:
"Survey data indicates engineering faculty at universities are far more likely to be conservative than people with other degrees, and far more likely to be religious."
Well, I'm an engineer and I work with engineers all day. I find the majority to be fairly liberal and not very religious. I always thought that it was a result of people being intelligent and familiar with the scientific method that made them less likely to swallow propaganda and dogma. Also, it is a largely foreign population and that is a factor since I meet the people who were educated enough to get jobs in different country from their own. I find that it is we Americans who are conservative and religious.
Also, the summary states:
"Gambetta and Hertog speculate that engineers combine these political predilections with a marked preference towards finding clearcut answers."
I speculate that Gamgetta and Hertog are fearful and jealous of engineers. I work in chip design and there are very few clearcut answers. Furthermore, your opinion on whether or not something is a good idea has no bearing on whether or not it actually is. I find that to be a major difference between engineering and the the more "normal" fields; you have to build things that work in the real world, your ability to persuade someone will not improve the quality of whatever it is you are building. If my chips don't work, I can't argue in front of a judge that they really do work. Nor can I publish a book speculating how good they really are. No, I fscked up and I have to deal with it.
[T]he Sparc M7 will have technologies for encryption acceleration and memory protection built into the chip.
Well, encryption acceleration has been available on x86 for a while and memory protection has been available on... well, I seem to remember that was the big feature the 286 had over the 8086, and it was only new to PCs at that point. That's a rather peculair thing to brag about, especially as the SPARC chip has always had it since it's inception.
Whatever though. I am kind of in two minds about this. Yaaay cool new sparc chip! ew, Oracle.
This processor includes encryption support... An ISA that no one uses!
Cost & Support! From the summary, this is described as a new effort to bring the SPARC processor cost down to where it can compete with Intel's high end parts.
High cost + no installed base = flop (megaflop?)
I remember back around 2002 when we got a fancy SPARC server at work that was multi-processor, big ram sun fire. The thing cost in the neighborhood of $40k. We also got an x86 server for about $2500 at the same time. When I ran large circuit simulation jobs on the x86 server, they ran about twice as fast as on the sun. Oops! Now, maybe this processor is more competitive with its performance, I don't know, but I don't think the situation has changed significantly.
I work in analog IC design (yes, the world really is analog) and I just don't see American engineers under a certain age. It is not about hiring practices. All the millennial aged engineers I know got their graduate degrees in the US after getting undergraduate degrees at home.
Engineering and Science used to be respected in America, but now it seems to be a bad thing. People would rather go into law or marketing than be a science nerd. All this talk about needing more STEM workers feels hollow when we still talk about going to the moon as our latest great achievement and a large segment of the population thinks that scientists are elitists with a nefarious agenda. It should come as no surprise that we are giving our technical competence away.
Now, to bring this home with a car analogy (and a moderately controversial one, although it shouldn't be), quoting the voltage of an electrical power source is not unlike quoting the torque of a car engine. Neither is a measure of the power available. Torque can be changed by going through a gearbox without changing the power delivered apart from the efficiency of the transmission. Similarly, voltage can be changed without changing the available power apart from the efficiency of the DC-DC converter. In both cases, load conditions matter. It would be like looking at the specs of an air wrench that has up to 450 lb-ft of torque and saying "Wow, that's as powerful as a Corvette engine!"
The MSR reactor is the best stove I've used. Fuel efficient and fast, if a bit pricey. Sometimes I consider using it in my kitchen instead of the range.
Think of it this way: Digital is math, Analog is Physics.
As mentioned before, the world is analog. Obvious things like audio and video interfaces need analog circuits and always will. Our ears, voice, and eyes are all analog. However, in todays circuits the analog content is growing not shrinking. Phones have batteries that need to be carefully managed. The digital circuits need many power supplies that need sophisticated regulation. These are all analog circuits. The wi-fi, bluetooth, cellular, NFC, and other radios are all very analog intensive circuits. There are a multitude of monitoring and control circuits on any modern piece of electronics that are all analog. The USB, HDMI, firewire (old, I know), Thunderbolt, etc. interfaces are all high-speed circuits that need analog drivers, receivers, and clocks that are analog. The CPUs, DSPs, etc all need clean clocks that are generated by PLLs that are analog even if they contain digital elements. Even the digital logic gates themselves are analog. The voltage levels that devine 0s and 1s are very analog. Their accuracy is quantified and defined to work with supply noise, clock jitter, and timing errors. All analog stuff. The digital math only works when these analog problems are reliably solved.
So please, keep saying that the world is digital and analog is going to die. It only provides more job security. We can't hire good analog designers fast enough.
A lot of the posts here seem to be some version of "This just shows that women aren't cut out for CS." My experience makes me think this may be an American issue.
I have been working in electrical engineering for 16 years. (I know, not CS but chip design is a tech field with commonalities.) It is a majority male field with approximately 15%-20% women. However, NONE of them that I see were raised in America. Most of the women I work with completed undergraduate degrees in China or India and got a graduate degree in the US. There must be some reason why American women are repelled from engineering. Or is it that Chinese and Indian women are just fundamentally better at tech than American women? (Before anyone brings up the H1 visa issue, that's not what is going on here. We have a hard time finding qualified candidates regardless of where they are from.)
It would seem that the fact that we (in the US) socialize girls from a very early age to stay away from thins like tech is relevant here. If you are curious, go into any major toy store (e.g. Toys R US, the independent stores are actually a lot better about this.) There are vanishingly few toys that are just toys anymore. There are only "girls" and "boys" toys. The girls toys are all pink and predominately princess themed. Now, you may say that this just confirms that boys and girls are different but you would be using circular logic to justify a pre-concieved notion.
Children are very sensitive to societal norms, both boys and girls. When high school girls feel that being too smart will make them less feminine and threaten boys, they will have a tendency to conform to these expectations. Sure, there will be some who don't but they will be fighting the system to some degree.
Saying that the low percentage of women in CS is proof that women don't like or aren't good at CS is simply pointing to the current state of affairs as a justification that it is the only possible way things can be. The reality is more nuanced.
The new semiconductor technology angle in the article seem highly fishy to me. Apart from the fact that the statement felt like it may have said "In 10 years we will all be living in colonies on the moon", III-V materials have been losing market share to silicon for decades.
The article mentions that great electron mobility of the III-V materials, which is true, but forgets to mention that they had poor hole mobility. Now I am not a process expert, so maybe there are new techniques to address this. However, over the past 20 years or so this meant that you couldn't make very good CMOS logic and had to use NMOS only architectures. This and the poor scaling has kept the III-Vs away from large scale integrated logic chips.
The III-V devices were used in RF circuits, but they were replaced by Si-Ge and now many RF circuits use regular silicon processes. The III-Vs are still useful for optics.
The truth is that silicon has many problems that may prevent the industry from continuing to scale circuits to smaller geometries and the available workarounds are generally painful. But, the other options are worse.
Maybe in 10 years we will all be using cell phones that use carbon nanotubes... in our colonies on the moon.
In reality, sound is all analog. Those vibrating strings on that guitar... analog. The vocal cords in the singers throat... analog. The vibrating membrane on those drums... you get the idea. The challenge comes in when you want to store that information so that you can play it back later (by creating vibrations in someone's eardrum most likely). In studio recordings, the limits to the noise floor, distortion, and frequency response is set by the analog circuits unless it is a really crappy system.
Before digital computers were available, the only options were to create static variations in physical media, i.e wax cylinders, vinyl records, magnetic tape, etc. The variations were analogous to the sound waves in the air (hence calling them analog).
Digital sound samples the sound in time and quantizes them so that the can be represented numerically. The beauty here is that the physical medium no longer matters. Once you have the numbers, you could store them on spinning magnetic disks or marbles in shot glasses. The difference is cost and practicality.
There is a lot of information theory to cover here, but the relevant basics are that the quality of the stored digital data (talking about PCM here, compression is an other layer entirely) is how finely you quantize each sample (e.g. bit depth) and how often you take samples (e.g. sample rate). In a well designed digital audio system, these factors will not be the limiting factor of your performance. This was true in the early days of CD audio. The dynamic range of the ADCs and DACs was less than what 16-bit quantization could achieve. Also, the analog anti-aliasing filters of the day could not handle the 44.1kHz sample rate well as they had to have very steep rolloff.
Nowadays, the studio ADCs are capable of greater than 120dB dynamic range (the best datasheet I've seen is 127dB) and oversampling techniques like delta-sigma modulation have made the analog filters much simpler. 24-bit resolution is more than enough to handle this. Higher sample rates were initially to help with the analog filtering, but that does not matter today since almost all audio DACs actually run at several MHz internally and use digital interpolation filters to generate the oversampled data.
So, the theoretical 144dB dynamic range of 24-bit audio is not achievable today and will likely not be for the foreseeable future. Going to 32-bit only makes sense if you already have 32-bit hardware and you don't save any resources by going to 24-bit. There is a slim case to make if you are doing lots of processing, but the advantage over 24 bit is just a practical one in most cases.
This kind of turned into a rant, but there seemed to be a lot of analog vs digital comments and I wanted to try to provide some perspective.
Krusty (to Bart): Bah. What good is respect without the moolah to back it up. Everywhere I go I see teachers driving Ferraris, research scientists drinking champagne.
This is a research idea that MAY be useful, the demise of CMOS silicon has been highly exaggerated.
From the summary:
"an inverter, which was able to switch on and off 500,000 times per second" -> 500kHz is not so great
"however, began to break down after 2 billion cycles" or about 1 second at current processor speeds. That increases to 4000 seconds at 500kHz, or a little more than an hour.
Also, we can put billions of error free transistors on a chip for a few dollars. THAT is the real hurdle that nothing else has been able to clear yet. We will likely be with silicon for a while after it stops shrinking for this reason.
not sure about "eFUSE" specifically, but the fuses on chips are used to write permanent data to a chip after manufacturing, typically during testing. If this is being done in the field and is un-doable, then it is most likely some non-volatile memory that they are calling "eFUSE". I'd bet that the firmware makes it look like a fuse except under certain circumstances.
Actual fuses in chips are thin pieces of metal wire that connect to the power supply voltage. When you try to read the voltage, that connection gives you a logic "1". To blow the fuse, you use a higher power supply than you would normally use and run enough current through the thin wire so that it melts and breaks the connection. Then, when you try to read back that bit it will read a logic "0" for ever. This is very handy for encryption, calibration data, and manufacturing information such as lot# and chip location. Many years back, IIRC, Intel tried to put serial numbers on their CPUs that could be read back by the software. They backed off after some public outcry. This used the fuses described above.
I went to the EMP (Experience Music Project) in Seattle, which is owned by Paul Allen. Naturally, they had these nifty little audio thingies that you carried arround with you that gave information relative to the exibit you were near.
Well, they all ran windowsCE. Mine crashed three times!! They had a technical support staff there and when I came to them with my problem, the person pulled out some kind of key, opened the unit, and then pulled out the battery to reboot the damn thing, every time!!! I was nearly on the floor laughing. My sister was with me at the time and she had heard my evangelizing about the virtues of linux, one of which being stability, and she didn't want to hear about it.
Anyway, I found it very ironic that I, as a linux user and advocate, had the newfangled device, powered by windowsCE, crash on me in what is supposed to be this showcase of technology. Horray for progress!
I have never known an Electrical Engineer with a PE. It all comes down to the interview. Good experience is important, but mostly demonstrating that you know what you are talking about and will be a good porson to work with will go a VERY long way.
I also agree about the HR cuts on resumes. I was looking for a job about 10 months ago. I had one year of experience at a no name startup and a bachelors degree. I had to solve a lot of problems on my own in that year and I grew as an engineer. But, when I mailed my resume to HR departments I did not get a single call back. Once I was able to get my hands on a real human being, the interview was great and I was getting offers on jobs that had stated requirements of a masters degree and four years experience. The interview, if you can get it, is what makes the difference.
I was told that I would only use 20% of what we learned in school. The important thing is to be able to learn how to find out what you need to know. People who only know what they were taught in school (or was covered in a certification test) will have very short carerrs in electrical engineering. Even though I took several classes on circuit design in school, I couldn't design my way out of a cardboard box untill I had been working for a year or two. Matt
I work as an analog designer in silicon valley. I am not a PE, no one I work with is a PE, I have never known a PE. (Electrical Engineer, that is.) I once asked one of my professors about certification (you should too) and he told me that it doesn't make any sence for EEs because the test is very broad and tends to be light in electronics anyway. It makes more sense for Civil engineers. Really, did any of your EE classes talk about stress analysis? Are they going to test you about carrier movement in semicondictors?
The only certification I needed was my degree. (It IS important that you go to an accredited university.) But, the more experience I get, the less important that becomes.
When I interview for a job, I am not asked to produce documentation for some test I took. No, I am asked "What have you designed that went into production? Tell me about it." Any EE who keeps his (her) head where the sun shines will quickly find out how much you know. In this buisiness, if someone is depending on a certification, it is because they don't know anything (and probably have pointy hair).
B.T.W, When you are interviewing and discussing any experience you may have, be prepared to answer not just what engineering decisions you made, but why.
Actually, the signals set by and to neurons are quite nonlinear and switch between two distinct levels. You could argue that our brains are digital. However, the architecture is fundamentally different.
I really think that the the way the brain works is quite different than the way out cpmputers work, espicially the memory. We don't have a discrete chunk of memory availabe that we fill with exact, independant entries like a digital memory would. The analogy of holography holds much better. First a hologram is distributed. That means that if you took a hologram and broke it in two pieces, you would not have the two halves of the original. Rather you would have two complete holograms, just with slightly less resolution in each one. Holograms are also associative. That is, if you construct a hologram by using the light from two objects, if you the illuminate the hologram with the light from one of the objects, you will see the other. That said, I think the analogy can be taken too far. The key is that the brain seems to be distributed similarly to holograms.
Our brains are also regenerative. Have you ever thought about something (say, an old memory) that was at first kinda fuzzy, then became more clear (either gradually or suddenly)? How would you quantify that? I don't claim to know what process is taking place there, but something happened to make the transition from fuzzy to clear.
An other HUGE case where the comparison of brains to computer memory is imagery. Firstly, we don't usually remember everything about a particular image, we remember what was important to us. And these can be time based (video) as well. How much disk space would it take to store the images you can conjure up in your brain? How about a text list of the ideas that you remember about those images? Quite different. Perhaps there is some kind of coding you could define for our brains, but now we're speculating an awfull lot.
OK, now here's some rampant speculation and conjecture:
Obviously, the functioning of the brain is rether complicated. In addition, I feel that many of the historic theories explaining brain function are deeply misguided at best. I think that the structure of the brain is related to fractals in a significant way. Fractals create complicated phenomenon from simple ideas applied on a large scale. That's not to say that if you crack open someone's head, you'll see a cheezy poster, but I think that a major breakthrough in understanding the brain would be the development of a branch of mathematics that incorporates fractals. A similar case was that vector mathematics was developed to explain E&M. Now, I am not a mathematician and my knowledge of fractals is limited to put it generously, but our brain is a very large scale object composed of relatively simple objects which follow simple rules. I think this is something worth not overlooking.
You know the most amazing ability of the human mind? The ability to ramble.
Slashdot Mirror
I think the idea is to use hydrogen as an energy storage alternative to batteries. The problem with batteries is that the basically suck. Sure, they suck a lot less than they used to but they are heavy, expensive, and take a long time to charge.
The (over-)simplified system with batteries is:
power source -> electricity distribution network -> charge battery -> power motor
The charge battery step is the long one. Even though EVs with a few hundred miles of range will work very well for the vast majority of urban travelers, the long charge time prevents the use of EVs in any long distance use cases.
Using hydrogen changes the (again, over-)simplified system to:
power source -> hydrogen generation -> fuel distribution network -> fill H2 tank -> fuel cell -> power motor
This system has its problems, to be sure. However, it replaces the "charge battery" step with "fill H2 tank" which can operate similarly to filling gasoline tanks today. It does require new infrastructure development, but then long distance travelers, transportation drivers, delivery drivers, etc. can go about their day and re-fill the H2 tanks when necessary.
Is it worth it? I don't know. But it is an other avenue to solving addressing the limitations with batteries.
Many statements from the summary directly contradict my personal experience. The summary states:
"Survey data indicates engineering faculty at universities are far more likely to be conservative than people with other degrees, and far more likely to be religious."
Well, I'm an engineer and I work with engineers all day. I find the majority to be fairly liberal and not very religious. I always thought that it was a result of people being intelligent and familiar with the scientific method that made them less likely to swallow propaganda and dogma. Also, it is a largely foreign population and that is a factor since I meet the people who were educated enough to get jobs in different country from their own. I find that it is we Americans who are conservative and religious.
Also, the summary states:
"Gambetta and Hertog speculate that engineers combine these political predilections with a marked preference towards finding clearcut answers."
I speculate that Gamgetta and Hertog are fearful and jealous of engineers. I work in chip design and there are very few clearcut answers. Furthermore, your opinion on whether or not something is a good idea has no bearing on whether or not it actually is. I find that to be a major difference between engineering and the the more "normal" fields; you have to build things that work in the real world, your ability to persuade someone will not improve the quality of whatever it is you are building. If my chips don't work, I can't argue in front of a judge that they really do work. Nor can I publish a book speculating how good they really are. No, I fscked up and I have to deal with it.
[T]he Sparc M7 will have technologies for encryption acceleration and memory protection built into the chip.
Well, encryption acceleration has been available on x86 for a while and memory protection has been available on... well, I seem to remember that was the big feature the 286 had over the 8086, and it was only new to PCs at that point. That's a rather peculair thing to brag about, especially as the SPARC chip has always had it since it's inception.
Whatever though. I am kind of in two minds about this. Yaaay cool new sparc chip! ew, Oracle.
This processor includes encryption support... An ISA that no one uses!
Cost & Support! From the summary, this is described as a new effort to bring the SPARC processor cost down to where it can compete with Intel's high end parts.
High cost + no installed base = flop (megaflop?)
I remember back around 2002 when we got a fancy SPARC server at work that was multi-processor, big ram sun fire. The thing cost in the neighborhood of $40k. We also got an x86 server for about $2500 at the same time. When I ran large circuit simulation jobs on the x86 server, they ran about twice as fast as on the sun. Oops! Now, maybe this processor is more competitive with its performance, I don't know, but I don't think the situation has changed significantly.
I work in analog IC design (yes, the world really is analog) and I just don't see American engineers under a certain age. It is not about hiring practices. All the millennial aged engineers I know got their graduate degrees in the US after getting undergraduate degrees at home.
Engineering and Science used to be respected in America, but now it seems to be a bad thing. People would rather go into law or marketing than be a science nerd. All this talk about needing more STEM workers feels hollow when we still talk about going to the moon as our latest great achievement and a large segment of the population thinks that scientists are elitists with a nefarious agenda. It should come as no surprise that we are giving our technical competence away.
That's the same combination I have on my luggage!
At least 123456 has one more digit.
Say it with me now... Voltage is not a measure of power!
Looking into the data sheet a little shows that this DC-DC converter maintains decent efficiency from a few microWatts to several hundred milliWatts;
http://www.ti.com/product/bq25...
Now, to bring this home with a car analogy (and a moderately controversial one, although it shouldn't be), quoting the voltage of an electrical power source is not unlike quoting the torque of a car engine. Neither is a measure of the power available. Torque can be changed by going through a gearbox without changing the power delivered apart from the efficiency of the transmission. Similarly, voltage can be changed without changing the available power apart from the efficiency of the DC-DC converter. In both cases, load conditions matter. It would be like looking at the specs of an air wrench that has up to 450 lb-ft of torque and saying "Wow, that's as powerful as a Corvette engine!"
I believe that Dr. Dre's PhD is in Electircal Engineering.
Your comments give me such a thrill,
But your comments don't pay my bills!
http://www.cascadedesigns.com/...
The MSR reactor is the best stove I've used. Fuel efficient and fast, if a bit pricey. Sometimes I consider using it in my kitchen instead of the range.
Think of it this way: Digital is math, Analog is Physics.
As mentioned before, the world is analog. Obvious things like audio and video interfaces need analog circuits and always will. Our ears, voice, and eyes are all analog. However, in todays circuits the analog content is growing not shrinking. Phones have batteries that need to be carefully managed. The digital circuits need many power supplies that need sophisticated regulation. These are all analog circuits. The wi-fi, bluetooth, cellular, NFC, and other radios are all very analog intensive circuits. There are a multitude of monitoring and control circuits on any modern piece of electronics that are all analog. The USB, HDMI, firewire (old, I know), Thunderbolt, etc. interfaces are all high-speed circuits that need analog drivers, receivers, and clocks that are analog. The CPUs, DSPs, etc all need clean clocks that are generated by PLLs that are analog even if they contain digital elements. Even the digital logic gates themselves are analog. The voltage levels that devine 0s and 1s are very analog. Their accuracy is quantified and defined to work with supply noise, clock jitter, and timing errors. All analog stuff. The digital math only works when these analog problems are reliably solved.
So please, keep saying that the world is digital and analog is going to die. It only provides more job security. We can't hire good analog designers fast enough.
A lot of the posts here seem to be some version of "This just shows that women aren't cut out for CS." My experience makes me think this may be an American issue.
I have been working in electrical engineering for 16 years. (I know, not CS but chip design is a tech field with commonalities.) It is a majority male field with approximately 15%-20% women. However, NONE of them that I see were raised in America. Most of the women I work with completed undergraduate degrees in China or India and got a graduate degree in the US. There must be some reason why American women are repelled from engineering. Or is it that Chinese and Indian women are just fundamentally better at tech than American women? (Before anyone brings up the H1 visa issue, that's not what is going on here. We have a hard time finding qualified candidates regardless of where they are from.)
It would seem that the fact that we (in the US) socialize girls from a very early age to stay away from thins like tech is relevant here. If you are curious, go into any major toy store (e.g. Toys R US, the independent stores are actually a lot better about this.) There are vanishingly few toys that are just toys anymore. There are only "girls" and "boys" toys. The girls toys are all pink and predominately princess themed. Now, you may say that this just confirms that boys and girls are different but you would be using circular logic to justify a pre-concieved notion.
Children are very sensitive to societal norms, both boys and girls. When high school girls feel that being too smart will make them less feminine and threaten boys, they will have a tendency to conform to these expectations. Sure, there will be some who don't but they will be fighting the system to some degree.
Saying that the low percentage of women in CS is proof that women don't like or aren't good at CS is simply pointing to the current state of affairs as a justification that it is the only possible way things can be. The reality is more nuanced.
The new semiconductor technology angle in the article seem highly fishy to me. Apart from the fact that the statement felt like it may have said "In 10 years we will all be living in colonies on the moon", III-V materials have been losing market share to silicon for decades.
The article mentions that great electron mobility of the III-V materials, which is true, but forgets to mention that they had poor hole mobility. Now I am not a process expert, so maybe there are new techniques to address this. However, over the past 20 years or so this meant that you couldn't make very good CMOS logic and had to use NMOS only architectures. This and the poor scaling has kept the III-Vs away from large scale integrated logic chips.
The III-V devices were used in RF circuits, but they were replaced by Si-Ge and now many RF circuits use regular silicon processes. The III-Vs are still useful for optics.
The truth is that silicon has many problems that may prevent the industry from continuing to scale circuits to smaller geometries and the available workarounds are generally painful. But, the other options are worse.
Maybe in 10 years we will all be using cell phones that use carbon nanotubes... in our colonies on the moon.
In reality, sound is all analog. Those vibrating strings on that guitar... analog. The vocal cords in the singers throat... analog. The vibrating membrane on those drums... you get the idea. The challenge comes in when you want to store that information so that you can play it back later (by creating vibrations in someone's eardrum most likely). In studio recordings, the limits to the noise floor, distortion, and frequency response is set by the analog circuits unless it is a really crappy system.
Before digital computers were available, the only options were to create static variations in physical media, i.e wax cylinders, vinyl records, magnetic tape, etc. The variations were analogous to the sound waves in the air (hence calling them analog).
Digital sound samples the sound in time and quantizes them so that the can be represented numerically. The beauty here is that the physical medium no longer matters. Once you have the numbers, you could store them on spinning magnetic disks or marbles in shot glasses. The difference is cost and practicality.
There is a lot of information theory to cover here, but the relevant basics are that the quality of the stored digital data (talking about PCM here, compression is an other layer entirely) is how finely you quantize each sample (e.g. bit depth) and how often you take samples (e.g. sample rate). In a well designed digital audio system, these factors will not be the limiting factor of your performance. This was true in the early days of CD audio. The dynamic range of the ADCs and DACs was less than what 16-bit quantization could achieve. Also, the analog anti-aliasing filters of the day could not handle the 44.1kHz sample rate well as they had to have very steep rolloff.
Nowadays, the studio ADCs are capable of greater than 120dB dynamic range (the best datasheet I've seen is 127dB) and oversampling techniques like delta-sigma modulation have made the analog filters much simpler. 24-bit resolution is more than enough to handle this. Higher sample rates were initially to help with the analog filtering, but that does not matter today since almost all audio DACs actually run at several MHz internally and use digital interpolation filters to generate the oversampled data.
So, the theoretical 144dB dynamic range of 24-bit audio is not achievable today and will likely not be for the foreseeable future. Going to 32-bit only makes sense if you already have 32-bit hardware and you don't save any resources by going to 24-bit. There is a slim case to make if you are doing lots of processing, but the advantage over 24 bit is just a practical one in most cases.
This kind of turned into a rant, but there seemed to be a lot of analog vs digital comments and I wanted to try to provide some perspective.
From "Bart the Fink" in season 7...
Krusty (to Bart): Bah. What good is respect without the moolah to back it up. Everywhere I go I see teachers driving Ferraris, research scientists drinking champagne.
This is a research idea that MAY be useful, the demise of CMOS silicon has been highly exaggerated.
From the summary:
"an inverter, which was able to switch on and off 500,000 times per second" -> 500kHz is not so great
"however, began to break down after 2 billion cycles" or about 1 second at current processor speeds. That increases to 4000 seconds at 500kHz, or a little more than an hour.
Also, we can put billions of error free transistors on a chip for a few dollars. THAT is the real hurdle that nothing else has been able to clear yet. We will likely be with silicon for a while after it stops shrinking for this reason.
not sure about "eFUSE" specifically, but the fuses on chips are used to write permanent data to a chip after manufacturing, typically during testing. If this is being done in the field and is un-doable, then it is most likely some non-volatile memory that they are calling "eFUSE". I'd bet that the firmware makes it look like a fuse except under certain circumstances.
Actual fuses in chips are thin pieces of metal wire that connect to the power supply voltage. When you try to read the voltage, that connection gives you a logic "1". To blow the fuse, you use a higher power supply than you would normally use and run enough current through the thin wire so that it melts and breaks the connection. Then, when you try to read back that bit it will read a logic "0" for ever. This is very handy for encryption, calibration data, and manufacturing information such as lot# and chip location. Many years back, IIRC, Intel tried to put serial numbers on their CPUs that could be read back by the software. They backed off after some public outcry. This used the fuses described above.
They compare the P4 to a drive through with one long, fast moving line and the G4 to walking inside where you have several shorter, slower lines.
Well, I used to work in fast food (many moons ago) and it is almost allways faster to walk in
I went to the EMP (Experience Music Project) in Seattle, which is owned by Paul Allen. Naturally, they had these nifty little audio thingies that you carried arround with you that gave information relative to the exibit you were near.
Well, they all ran windowsCE. Mine crashed three times!! They had a technical support staff there and when I came to them with my problem, the person pulled out some kind of key, opened the unit, and then pulled out the battery to reboot the damn thing, every time!!! I was nearly on the floor laughing. My sister was with me at the time and she had heard my evangelizing about the virtues of linux, one of which being stability, and she didn't want to hear about it.
Anyway, I found it very ironic that I, as a linux user and advocate, had the newfangled device, powered by windowsCE, crash on me in what is supposed to be this showcase of technology. Horray for progress!
I have never known an Electrical Engineer with a PE. It all comes down to the interview. Good experience is important, but mostly demonstrating that you know what you are talking about and will be a good porson to work with will go a VERY long way.
I also agree about the HR cuts on resumes. I was looking for a job about 10 months ago. I had one year of experience at a no name startup and a bachelors degree. I had to solve a lot of problems on my own in that year and I grew as an engineer. But, when I mailed my resume to HR departments I did not get a single call back. Once I was able to get my hands on a real human being, the interview was great and I was getting offers on jobs that had stated requirements of a masters degree and four years experience. The interview, if you can get it, is what makes the difference.
Matt
I was told that I would only use 20% of what we learned in school. The important thing is to be able to learn how to find out what you need to know. People who only know what they were taught in school (or was covered in a certification test) will have very short carerrs in electrical engineering. Even though I took several classes on circuit design in school, I couldn't design my way out of a cardboard box untill I had been working for a year or two. Matt
I work as an analog designer in silicon valley. I am not a PE, no one I work with is a PE, I have never known a PE. (Electrical Engineer, that is.) I once asked one of my professors about certification (you should too) and he told me that it doesn't make any sence for EEs because the test is very broad and tends to be light in electronics anyway. It makes more sense for Civil engineers. Really, did any of your EE classes talk about stress analysis? Are they going to test you about carrier movement in semicondictors?
The only certification I needed was my degree. (It IS important that you go to an accredited university.) But, the more experience I get, the less important that becomes.
When I interview for a job, I am not asked to produce documentation for some test I took. No, I am asked "What have you designed that went into production? Tell me about it." Any EE who keeps his (her) head where the sun shines will quickly find out how much you know. In this buisiness, if someone is depending on a certification, it is because they don't know anything (and probably have pointy hair).
B.T.W, When you are interviewing and discussing any experience you may have, be prepared to answer not just what engineering decisions you made, but why.
Matt
I tried to log in but my message was sent as an AC. I even used preview.
Actually, the signals set by and to neurons are quite nonlinear and switch between two distinct levels. You could argue that our brains are digital. However, the architecture is fundamentally different.
Matt
I really think that the the way the brain works is quite different than the way out cpmputers work, espicially the memory. We don't have a discrete chunk of memory availabe that we fill with exact, independant entries like a digital memory would. The analogy of holography holds much better. First a hologram is distributed. That means that if you took a hologram and broke it in two pieces, you would not have the two halves of the original. Rather you would have two complete holograms, just with slightly less resolution in each one. Holograms are also associative. That is, if you construct a hologram by using the light from two objects, if you the illuminate the hologram with the light from one of the objects, you will see the other. That said, I think the analogy can be taken too far. The key is that the brain seems to be distributed similarly to holograms.
Our brains are also regenerative. Have you ever thought about something (say, an old memory) that was at first kinda fuzzy, then became more clear (either gradually or suddenly)? How would you quantify that? I don't claim to know what process is taking place there, but something happened to make the transition from fuzzy to clear.
An other HUGE case where the comparison of brains to computer memory is imagery. Firstly, we don't usually remember everything about a particular image, we remember what was important to us. And these can be time based (video) as well. How much disk space would it take to store the images you can conjure up in your brain? How about a text list of the ideas that you remember about those images? Quite different. Perhaps there is some kind of coding you could define for our brains, but now we're speculating an awfull lot.
OK, now here's some rampant speculation and conjecture:
Obviously, the functioning of the brain is rether complicated. In addition, I feel that many of the historic theories explaining brain function are deeply misguided at best. I think that the structure of the brain is related to fractals in a significant way. Fractals create complicated phenomenon from simple ideas applied on a large scale. That's not to say that if you crack open someone's head, you'll see a cheezy poster, but I think that a major breakthrough in understanding the brain would be the development of a branch of mathematics that incorporates fractals. A similar case was that vector mathematics was developed to explain E&M. Now, I am not a mathematician and my knowledge of fractals is limited to put it generously, but our brain is a very large scale object composed of relatively simple objects which follow simple rules. I think this is something worth not overlooking.
You know the most amazing ability of the human mind? The ability to ramble.