22/7 is only good out to two decimal places. Close enough for horseshoes I guess, but not very accurate after three significant digits.
Pi = (4/1) - (4/3) + (4/5) - (4/7) + (4/9) - (4/11) + (4/13) - (4/15)... works, converges eventually to as many decimal places as you may need. Just keep cranking out until the digits you need stop changing.
There is a quicker way... Pi = 3 + 4/(2*3*4) - 4/(4*5*6) + 4/(6*7*8) - 4/(8*9*10) + 4/(10*11*12) - (4/(12*13*14)... Which converges faster but takes a bit more math.
But, hey, all these are all ways to approximate of Pi. Mine include a way to get as many digits as you may need, yours is stuck at 3 digits, which is about all you can get on a slide rule.
A real nerd would know how to calculate Pi from scratch, no shotgun required...
Pi = (4/1) - (4/3) + (4/5) - (4/7) + (4/9) - (4/11) + (4/13) - (4/15)... (keep going until you get the number of decimal places you need.)
Why bother with the shotgun and waste the rounds conducting this worthless experiment. You are proving nothing but that you know how to draw a square and an arc and count.
OR, just get some unsuspecting length of string, a ruler and a round object like a jar or large can. Measure the circumference and divide by diameter, voila! Pi.
I'm not saying people cannot hear 100Hz, I'm saying that most audio equipment sold doesn't reproduce said frequencies. Systems capable of producing base at 150Hz and down are usually expensive and many people just don't spend the money on such systems.
Most people can clearly hear well below 100Hz.... They just don't usually listen to such material because of financial constraints. Most people cannot hear anything above 18KHz, not because audio equipment doesn't produce it, but because they cannot hear it.
The most effective managers praise liberally and do it in public as often as possible. Effective managers also rebuke as little as possible and try to do that in private.
They also demonstrate professional behavior and language as much as possible, but that's more about setting the example than managing folks.
I prefer to work for the most effective managers myself, especially as a volunteer. You do what you want.
They are turning on the built in microphone? EXCELLENT! Google can sure do stuff I never imagined possible...
I have an old cheap laptop (still running XP) that doesn't have a microphone built in so somehow I don't think they are doing anything of the kind, at least to me.
You forgot paying that admin to manage the key and stand there while you get the office supplies you needed, which takes her about 10 hours per year at $20/hour...
Portability of learned skills means you don't have to re-train your workers.
Looks like and acts like are totally different things. While looking like windows might get you past the initial "it's not what I know" reaction, it's still going to take training to take windows folks into the brave new world of Linux.
changing the servers to liquid cooling won't fix that.
Not that I disagree on most of what you said, but on this point I think there is a possible efficiency gain. What we do today is pump cool air into systems and cool the air to 70 degrees F using standard Air Conditioning systems. AC systems use a liquid phase change process, fans and compressors which take large amounts of power to run.
If we can design liquid cooled systems that operate at higher temperatures, and get that temperature significantly above what you can reliably get from a water evaporator, you might be able to avoid the whole AC (phase change liquid cooling) systems and their power consumption by directly cooling a liquid. Avoiding the phase change AC process will require that the hot liquid temperature to be in excess of 120 degrees F and means the hardware will be seeing at least that temperature internally. But this higher working temperature would allow us to dump the heat directly into the ambient air by building heat exchangers which where big enough, or by using evaporating water to cool the fluid. The trick is to get the temperature differential high enough between inside the server and outdoors so we don't have to employ traditional AC methods that involve the phase change of a refrigerants, compressors and fans.
"Molar water?" Even The Google has no idea what that is.
Perhaps you meant "pure water" or just "water?"
I think that's what he means. The problem is that water is VERY reactive and is really an excellent solvent. Pure water has a fairly high PH, which means that it will leach (dissolve) most metals over time an picks up ions. As you point out, it only takes a few ions dissolved in water and it becomes an excellent conductor.
As such, water is an extremely poor choice for cooling electronics. It might be environmentally safe, but it's pretty much not going to be an insulator if it is exposed to anything metal. Coating everything in plastic might be an option, but that defeats the purpose by impeding heat transfer.
I like mineral oil myself. Not very environmentally friendly and really messy, but easy to get, it can transfer a lot of heat and doesn't react with most things electronic..
This is the most insane article I have ever read.... The deaf culture ???? Beyond words...
You are apparently ignorant of the fact that there IS a deaf culture. It is driven by a common language and has its own customs. One such custom is that your sign name must be given by an actual deaf person. There are more.
Americans tend to be very culturally illiterate as a whole. It is one of the reasons we are not so well liked overseas, because we are not sensitive to local culture and we end up coming across as rude and demanding rich folks. I'm not deaf, nor do I sign very much, but we have the same problem with their culture, we are woefully uninformed and ignorant of their culture and attitudes like yours tells me why.
Where I don't think the attempt to shore up the deaf culture and isolate it from those who might want to actually not be deaf is a good thing, one cannot simply dismiss their culture. It exists because *hearing* folks refused to learn sign language, not because deaf people could help not being able to speak.
Imagine if you didn't need to handle explosives like Cordite as propellents anymore. This will reduce storage space and make a battleship's gun turret a while lot safer place to work. One small spark won't set off a magazine anymore.
"Muzzle velocity" is higher, so the distance you can throw something is a bit further, like 5x further. If you can fire further, you have a huge advantage because you can hit your opponent before he can shoot at you. Or if you are doing ground support, you can fire further inland.
I'm assuming a rail gun will be faster to reload. Might take some time to recharge the power supply, but surely we can fire faster than a Mark 7's 2 rounds a minute. More pounds and rounds on the target than your opponent is always better.
Finally, it may be possible to more strictly control forces on the shell when firing it, which may make it possible to put more technology IN the shells, and still get very high velocity. Imagine a shell that can adjust it's flight path, even slightly, which means you can fire in the general direction you want, then fine tune the aim in flight. (I assume they don't do that now..)
Issues to watch out for: First, Rail guns tend to have tracks (rails) and said rails usually have difficulty with wear due to the huge forces and high speeds involved. Hopefully they have engineered the better materials. Second, power supplies for rail guns have to be designed to provide HUGE impulse powers with power generation systems wanting to be running at steady state. You have to match the two. Finally, weapons like this usually mean you have to redesign the whole weapons system, a process that literally takes decades.
You are discussing "mixing" tones, where you take two tones and mix them. You will find over and under tones in the mixed signal that are separated by multiples of the difference in the two frequencies. It is because of this that you want to over sample by at least 2 times the highest frequency of the signal you want to reproduce (usually a bit more than 2 times to allow for the use of less than ideal analog filters). You choose an unfortunate mixture of tones in your example though. Keep the two tones closer together and the mixing products will be closer. Use 1Khz and 1.5Khz which will have mixing products every 500Hz which spreads out within the normal pas-band of most audio equipment.
The problem for you though is with say a 48Khz sample rate, the bandwidth approaches 24Khz. Actual bandwidth will be somewhat less, say 20Khz, owing to the analog filters you need to put before you encode during recording and after you decode on playback to avoid aliasing signals where they don't belong, due to the mixing of the sample rate frequency and the material. If you design your A to D and D to A circuits correctly and have enough roll off in your filters outside the pass band, these aliased signals will be effectively masked and you won't be able to hear them, even though they are technically measurable.
I'm guessing that what you *might* hear are unwanted side effects of digital transcoding and not signals which where part of the original material. When you listen to the same material, based on the same recording (i.e. not recorded separately) yet at different bit rates, somebody has done the conversion from one bit rate to another using some digital conversion techniques. Transcoding is pretty much going to cause noticeable artifacts within the commonly reproduced frequency spectrum (100hz though 16Khz). This is especially true for transcoding between sample rates, and less apparent when encoding (u-Law, vrs a-Law) but still adds to the S/N of the material. Even average listeners can be trained to hear the difference in side by side comparisons of transcoded material, but there are FEW who can actually tell, reliably, which signal is at a higher bit rate, even with all other things being equal.
So, I contend that there really is no advantage to going to higher bit rates, once you have about the equivalent to CD quality on the best of equipment and for most playback equipment out there, quite a bit less. If your playback equipment is limited to 200Hz to 16Khz (and unless you spent a LOT of money, that's what you likely have) don't bother with the high bit rate stuff. Certainly don't pay extra for it. The ONLY reason you possibly MIGHT want to do high bit rates is if you like to transcode down to lower rates on various devices. When transcoding, you can usually lower the artifacts of the conversion process if you start with higher bit rates, but almost nobody has hearing that is that good, and fewer of those have equipment where it's going to be possible anyway. And there is a dirty little secret many equipment manufactures don't tell you about MP3 players. Few of them actually have decoding hardware for everything they can play, and many just transcode the material into something the D-A devices understand. So many times, what you *really* hear are artifacts induced by the equipment you choose and not stuff that is actually IN the data you are feeding it.
Actually, the invasion of Iraq was about terror and removing a dictator that said he had WMD's and harbored terrorists.
All the rest of your tripe is stuff that has been trumped up in an effort to discredit the president who initiated the action, even though it was will full UN and congressional approval and thus not totally his responsibility. After all, he may have made the final decision, but pretty much everybody involved agreed (the UN, Congress, NATO countries etc..) that it was the right thing to do. FEW where out there decrying the injustice of the action BEFORE it was done, even though many would love to revise history to make it sound like they opposed the war when they actually voted FOR the use of force.
So, I will say this. I think YOU are the one who is revising history to suit your argument and political leanings. At which point, this discussion stops being useful and ends, at least for me.... Full Stop.
In short, if you are afraid of knives, get out of the kitchen.
Which, in this case, I do already. Not that I'm afraid of Torvalds, but that I have better and more rewarding things to do with my time that deal with his temperament. But I've said all this before.
Care to go around the bush again? Personally I don't. Full Stop for me.
Middle C (C4) is 261.626 Hz, Base C (C3) is 130.813, and Low C (C2) is 65.406. So, you are telling me you, as a baratone routinely can hit "low C" i.e. "C2"? You must be mistaken or I'm misunderstanding you, would that not be Base C or (C3)? Low C (C2) is the note two lines BELOW the base-clef, the last "C" on an 88 key piano. I'm not sure I've ever heard of a base who can routinely go that low.
But even so, 100 Hz is below what most consumer quality audio equipment will do. Most speaker systems roll of fairly fast below 200 and you will have to have a powered sub-woofer to do much more. Even then, these things roll off even quicker below 40 Hz unless you go physically big and electrically powerful. But for lows, there is the law of diminishing returns. Every time you half the frequency, you double the size and at least double the power (or more). But few people ever bother spending that kind of money.
Remember, I'm talking about "consumer grade" stuff routinely sold by large box retailers for a few C notes which is the target audience for 99.99% of all the recordings sold. They are playing their hip-hop, country, rap, pop or possibly jazz on the boom box as loud as it will go. Quality is defined as being able to survive the abuse and being loud enough to make it hard to hear the conversation across the room. Nobody really cares what the %THD is or if the amp is clipping because nobody there can tell the difference.
Then there are the "audiophiles" which fall into two classes. Those who are out to spend money and those who can actually HEAR what they are buying. The money spenders fall for all the sales hype and salesman tricks (like making the more expensive speakers louder) and buy stuff they really don't need. These guys stress out over THD and SPL's without knowing what these numbers mean or if anybody (including themselves) could possibly hear the difference they just paid a premium to achieve. Then you have the real listeners who understand that it's not about specs, but more about matching the equipment to the room and selecting the location of the speakers and listener than getting another 0.1% better THD and it becomes more important to select your recording sources and processing equipment that matches the material you like over spending just to spend.
Either way, the limits of human hearing are quite clear. Nothing above 18Khz for most of us. While the limits of what we can afford for audio equipment means we don't listen to anything under about 100Hz. One is physical, the other is about money.
I think that an article whose author claims that "Germanium... doesn't occur naturally" and that "400Ghz... should make for some strong signals" ought to be taken with a very large lab-grown monocrystal of salt.
Very good advice. I'd mod this up if I had any points today.
That seems like an odd announcement to make...if it's just one more step in the research process and this doesn't make graphene a viable replacement *yet*...
It's about the research funding and securing more... They must be out of money so they need to go out hawking their wares to secure more R&D funding.
Way back in the 80's, Popular Electronics published a series of articles that described an active crossover that split 150Hz (or so) off and sent it out a separate output to drive a sub-woofer. They also had two designs for a ported enclosure that used either a 18" or 22" JBL driver. The smaller of the two, which was as big as a coffee table, required 200W and would get you down to about 30Hz on it's own or with equalization you could get down to 20 Hz. The 22" driver design was about 50% bigger enclosure and it would get you down to 16Hz with equalization and about 400 Watts. Always dreamed of doing this and I kept the articles all these years. Now days, you cannot buy the drivers and active crossovers are really cheap so why build your own?
But who needs 20hz? That's more earthquake you feel than sound you hear. Most stereos are going to roll off the low end someplace above 60Hz. The size of the speaker enclosures and the power required start to get really large, really quick as you go much under 100Hz. To do 20 Hz properly is going to take a really large enclosure and a large speaker (something like 18" or bigger) and you will need quite a bit of power (300 Watts or so for 100 Wat stereo) to get a flat response from 100Hz down to 20Hz. But this is WAY below what most stereo systems can do.
But, I'm claiming that nobody really cares about anything below about 100Hz. There is very little material that you can find that uses much below 100Hz beyond action movies and some specialized recordings. (I have some of these recordings). Nobody has equipment capable of reproducing such low frequencies, so in order to avoid 60 Hz hum issues they just cut everything below about 100 in the studio. I'm also claiming that most material doesn't have much content above 16Kzh either, mainly because nobody can hear it and most stereo systems cannot reproduce it. Most recording studios just EQ away anything above 18Khz and below 100Hz just before they compress the life out of their recordings anyway, especially for any material like Country, Rock, Pop, Jazz (less so) that goes out over the radio. Classical is *sometimes* left alone, but in my experience the recordings are usually not done in studios and usually there are significant deficiencies in microphone selection and placement not to mention issues from the acoustics of the venue. My point being, that there is extremely limited material out there where anybody could tell the difference between 20-20Kz system and a 100-18Kz system and of that material, very little of it is anything you'd be willing to listen to in the first place.
There are people who insist that they can hear the difference
They are fooling themselves if they think they can tell which was recorded with the higher bit rate. What they MIGHT be able to hear are the trans-coding artifacts, but in most cases, I'll bet they really are just hearing the limitations of their equipment (distortion products) caused by encoding/decoding artifacts that are outside their ability to hear.
Not exactly. Most audio systems out there cannot reproduce much above 16Khz or below 60Hz. Your average amplifiers and speakers are going to be rolling off pretty badly at 16Khz so even if YOU could hear stuff above 20Khz, it won't be coming from your speakers trying to reproduce the material. You might be hearing distortion products that high, but I doubt it. Headphones tend to be a bit better on the high end, but even then the average starts to roll off at 20Khz but most of us simply cannot hear above 20Kzh, ever.
Human hearing rolls off pretty badly above 18Khz, even for the young. It's worse when you get older. And I dare say that you know NOBODY who can hear much above 25Khz and if they do they are under 25 years old. Nobody is going to hear 30K, so I have no idea how you think you can hear 100K. What you MIGHT be hearing is distortion products caused by your equipment trying to reproduce material above 20K, but these products will be BELOW 20K and are actually DISTORTION not really the material.
So your point is correct in part, just not for the reasons you suggest. I'll bet you cannot hear above 25Khz (20Khz if you are over 30) measured using a pure single frequency sine tone no more than 10dB louder than a minimum discernible 1Khz pure tone. Higher sampling rates really only matter when transcoding between sampling rates, which points to the ONLY real reason you would like to over sample beyond the Nyquest rate for the highest frequency you can hear. What's more, I'll bet that while you MIGHT be able to hear a difference, you won't be able to reliability tell me which material was recorded at a higher sample rate if you let me choose the material. In fact, I'll bet I can get you to prefer the lower sample rate more often than not.
"cannot tell the difference" -- that's not what is being said here. Instead, the violinists were asked which ones they preferred. Certainly they could distinguish between them.
One would assume that a preferred violin would be the one that was both easy to tune, play and sounded the best. I'm personally surprised that the older ones where not the preferred ones, but if you think about it, it sort of makes sense.
Slashdot Mirror
You must be loads of laughs at a party.
I think so, but nobody ever invites me to more than one....
22/7 is only good out to two decimal places. Close enough for horseshoes I guess, but not very accurate after three significant digits.
Pi = (4/1) - (4/3) + (4/5) - (4/7) + (4/9) - (4/11) + (4/13) - (4/15) ... works, converges eventually to as many decimal places as you may need. Just keep cranking out until the digits you need stop changing.
There is a quicker way... Pi = 3 + 4/(2*3*4) - 4/(4*5*6) + 4/(6*7*8) - 4/(8*9*10) + 4/(10*11*12) - (4/(12*13*14)... Which converges faster but takes a bit more math.
But, hey, all these are all ways to approximate of Pi. Mine include a way to get as many digits as you may need, yours is stuck at 3 digits, which is about all you can get on a slide rule.
A real nerd would know how to calculate Pi from scratch, no shotgun required...
Pi = (4/1) - (4/3) + (4/5) - (4/7) + (4/9) - (4/11) + (4/13) - (4/15) ... (keep going until you get the number of decimal places you need.)
Why bother with the shotgun and waste the rounds conducting this worthless experiment. You are proving nothing but that you know how to draw a square and an arc and count.
OR, just get some unsuspecting length of string, a ruler and a round object like a jar or large can. Measure the circumference and divide by diameter, voila! Pi.
I'm not saying people cannot hear 100Hz, I'm saying that most audio equipment sold doesn't reproduce said frequencies. Systems capable of producing base at 150Hz and down are usually expensive and many people just don't spend the money on such systems.
Most people can clearly hear well below 100Hz.... They just don't usually listen to such material because of financial constraints. Most people cannot hear anything above 18KHz, not because audio equipment doesn't produce it, but because they cannot hear it.
The most effective managers praise liberally and do it in public as often as possible. Effective managers also rebuke as little as possible and try to do that in private.
They also demonstrate professional behavior and language as much as possible, but that's more about setting the example than managing folks.
I prefer to work for the most effective managers myself, especially as a volunteer. You do what you want.
They are turning on the built in microphone? EXCELLENT! Google can sure do stuff I never imagined possible...
I have an old cheap laptop (still running XP) that doesn't have a microphone built in so somehow I don't think they are doing anything of the kind, at least to me.
Spying on the citizens and visitors of London by using public bike data... For SHAME you guys....
Oh... wait...
You forgot paying that admin to manage the key and stand there while you get the office supplies you needed, which takes her about 10 hours per year at $20/hour...
Sure it can... but for the love of God--why??
Portability of learned skills means you don't have to re-train your workers.
Looks like and acts like are totally different things. While looking like windows might get you past the initial "it's not what I know" reaction, it's still going to take training to take windows folks into the brave new world of Linux.
changing the servers to liquid cooling won't fix that.
Not that I disagree on most of what you said, but on this point I think there is a possible efficiency gain. What we do today is pump cool air into systems and cool the air to 70 degrees F using standard Air Conditioning systems. AC systems use a liquid phase change process, fans and compressors which take large amounts of power to run.
If we can design liquid cooled systems that operate at higher temperatures, and get that temperature significantly above what you can reliably get from a water evaporator, you might be able to avoid the whole AC (phase change liquid cooling) systems and their power consumption by directly cooling a liquid. Avoiding the phase change AC process will require that the hot liquid temperature to be in excess of 120 degrees F and means the hardware will be seeing at least that temperature internally. But this higher working temperature would allow us to dump the heat directly into the ambient air by building heat exchangers which where big enough, or by using evaporating water to cool the fluid. The trick is to get the temperature differential high enough between inside the server and outdoors so we don't have to employ traditional AC methods that involve the phase change of a refrigerants, compressors and fans.
Transformer oil - move out!
Fast forward to the 80's and please ditch the PCB's. Just switch to mineral oil. Costs a bit more, but does the same job.
"Molar water?" Even The Google has no idea what that is.
Perhaps you meant "pure water" or just "water?"
I think that's what he means. The problem is that water is VERY reactive and is really an excellent solvent. Pure water has a fairly high PH, which means that it will leach (dissolve) most metals over time an picks up ions. As you point out, it only takes a few ions dissolved in water and it becomes an excellent conductor.
As such, water is an extremely poor choice for cooling electronics. It might be environmentally safe, but it's pretty much not going to be an insulator if it is exposed to anything metal. Coating everything in plastic might be an option, but that defeats the purpose by impeding heat transfer.
I like mineral oil myself. Not very environmentally friendly and really messy, but easy to get, it can transfer a lot of heat and doesn't react with most things electronic..
This is the most insane article I have ever read.... The deaf culture ???? Beyond words...
You are apparently ignorant of the fact that there IS a deaf culture. It is driven by a common language and has its own customs. One such custom is that your sign name must be given by an actual deaf person. There are more.
Americans tend to be very culturally illiterate as a whole. It is one of the reasons we are not so well liked overseas, because we are not sensitive to local culture and we end up coming across as rude and demanding rich folks. I'm not deaf, nor do I sign very much, but we have the same problem with their culture, we are woefully uninformed and ignorant of their culture and attitudes like yours tells me why.
Where I don't think the attempt to shore up the deaf culture and isolate it from those who might want to actually not be deaf is a good thing, one cannot simply dismiss their culture. It exists because *hearing* folks refused to learn sign language, not because deaf people could help not being able to speak.
Many!
Imagine if you didn't need to handle explosives like Cordite as propellents anymore. This will reduce storage space and make a battleship's gun turret a while lot safer place to work. One small spark won't set off a magazine anymore.
"Muzzle velocity" is higher, so the distance you can throw something is a bit further, like 5x further. If you can fire further, you have a huge advantage because you can hit your opponent before he can shoot at you. Or if you are doing ground support, you can fire further inland.
I'm assuming a rail gun will be faster to reload. Might take some time to recharge the power supply, but surely we can fire faster than a Mark 7's 2 rounds a minute. More pounds and rounds on the target than your opponent is always better.
Finally, it may be possible to more strictly control forces on the shell when firing it, which may make it possible to put more technology IN the shells, and still get very high velocity. Imagine a shell that can adjust it's flight path, even slightly, which means you can fire in the general direction you want, then fine tune the aim in flight. (I assume they don't do that now..)
Issues to watch out for: First, Rail guns tend to have tracks (rails) and said rails usually have difficulty with wear due to the huge forces and high speeds involved. Hopefully they have engineered the better materials. Second, power supplies for rail guns have to be designed to provide HUGE impulse powers with power generation systems wanting to be running at steady state. You have to match the two. Finally, weapons like this usually mean you have to redesign the whole weapons system, a process that literally takes decades.
Go Navy, this is worth the R&D money..
You are discussing "mixing" tones, where you take two tones and mix them. You will find over and under tones in the mixed signal that are separated by multiples of the difference in the two frequencies. It is because of this that you want to over sample by at least 2 times the highest frequency of the signal you want to reproduce (usually a bit more than 2 times to allow for the use of less than ideal analog filters). You choose an unfortunate mixture of tones in your example though. Keep the two tones closer together and the mixing products will be closer. Use 1Khz and 1.5Khz which will have mixing products every 500Hz which spreads out within the normal pas-band of most audio equipment.
The problem for you though is with say a 48Khz sample rate, the bandwidth approaches 24Khz. Actual bandwidth will be somewhat less, say 20Khz, owing to the analog filters you need to put before you encode during recording and after you decode on playback to avoid aliasing signals where they don't belong, due to the mixing of the sample rate frequency and the material. If you design your A to D and D to A circuits correctly and have enough roll off in your filters outside the pass band, these aliased signals will be effectively masked and you won't be able to hear them, even though they are technically measurable.
I'm guessing that what you *might* hear are unwanted side effects of digital transcoding and not signals which where part of the original material. When you listen to the same material, based on the same recording (i.e. not recorded separately) yet at different bit rates, somebody has done the conversion from one bit rate to another using some digital conversion techniques. Transcoding is pretty much going to cause noticeable artifacts within the commonly reproduced frequency spectrum (100hz though 16Khz). This is especially true for transcoding between sample rates, and less apparent when encoding (u-Law, vrs a-Law) but still adds to the S/N of the material. Even average listeners can be trained to hear the difference in side by side comparisons of transcoded material, but there are FEW who can actually tell, reliably, which signal is at a higher bit rate, even with all other things being equal.
So, I contend that there really is no advantage to going to higher bit rates, once you have about the equivalent to CD quality on the best of equipment and for most playback equipment out there, quite a bit less. If your playback equipment is limited to 200Hz to 16Khz (and unless you spent a LOT of money, that's what you likely have) don't bother with the high bit rate stuff. Certainly don't pay extra for it. The ONLY reason you possibly MIGHT want to do high bit rates is if you like to transcode down to lower rates on various devices. When transcoding, you can usually lower the artifacts of the conversion process if you start with higher bit rates, but almost nobody has hearing that is that good, and fewer of those have equipment where it's going to be possible anyway. And there is a dirty little secret many equipment manufactures don't tell you about MP3 players. Few of them actually have decoding hardware for everything they can play, and many just transcode the material into something the D-A devices understand. So many times, what you *really* hear are artifacts induced by the equipment you choose and not stuff that is actually IN the data you are feeding it.
Actually, the invasion of Iraq was about terror and removing a dictator that said he had WMD's and harbored terrorists.
All the rest of your tripe is stuff that has been trumped up in an effort to discredit the president who initiated the action, even though it was will full UN and congressional approval and thus not totally his responsibility. After all, he may have made the final decision, but pretty much everybody involved agreed (the UN, Congress, NATO countries etc..) that it was the right thing to do. FEW where out there decrying the injustice of the action BEFORE it was done, even though many would love to revise history to make it sound like they opposed the war when they actually voted FOR the use of force.
So, I will say this. I think YOU are the one who is revising history to suit your argument and political leanings. At which point, this discussion stops being useful and ends, at least for me.... Full Stop.
In short, if you are afraid of knives, get out of the kitchen.
Which, in this case, I do already. Not that I'm afraid of Torvalds, but that I have better and more rewarding things to do with my time that deal with his temperament. But I've said all this before.
Care to go around the bush again? Personally I don't. Full Stop for me.
Middle C (C4) is 261.626 Hz, Base C (C3) is 130.813, and Low C (C2) is 65.406. So, you are telling me you, as a baratone routinely can hit "low C" i.e. "C2"? You must be mistaken or I'm misunderstanding you, would that not be Base C or (C3)? Low C (C2) is the note two lines BELOW the base-clef, the last "C" on an 88 key piano. I'm not sure I've ever heard of a base who can routinely go that low.
But even so, 100 Hz is below what most consumer quality audio equipment will do. Most speaker systems roll of fairly fast below 200 and you will have to have a powered sub-woofer to do much more. Even then, these things roll off even quicker below 40 Hz unless you go physically big and electrically powerful. But for lows, there is the law of diminishing returns. Every time you half the frequency, you double the size and at least double the power (or more). But few people ever bother spending that kind of money.
Remember, I'm talking about "consumer grade" stuff routinely sold by large box retailers for a few C notes which is the target audience for 99.99% of all the recordings sold. They are playing their hip-hop, country, rap, pop or possibly jazz on the boom box as loud as it will go. Quality is defined as being able to survive the abuse and being loud enough to make it hard to hear the conversation across the room. Nobody really cares what the %THD is or if the amp is clipping because nobody there can tell the difference.
Then there are the "audiophiles" which fall into two classes. Those who are out to spend money and those who can actually HEAR what they are buying. The money spenders fall for all the sales hype and salesman tricks (like making the more expensive speakers louder) and buy stuff they really don't need. These guys stress out over THD and SPL's without knowing what these numbers mean or if anybody (including themselves) could possibly hear the difference they just paid a premium to achieve. Then you have the real listeners who understand that it's not about specs, but more about matching the equipment to the room and selecting the location of the speakers and listener than getting another 0.1% better THD and it becomes more important to select your recording sources and processing equipment that matches the material you like over spending just to spend.
Either way, the limits of human hearing are quite clear. Nothing above 18Khz for most of us. While the limits of what we can afford for audio equipment means we don't listen to anything under about 100Hz. One is physical, the other is about money.
I think that an article whose author claims that "Germanium ... doesn't occur naturally" and that "400Ghz ... should make for some strong signals" ought to be taken with a very large lab-grown monocrystal of salt.
Very good advice. I'd mod this up if I had any points today.
That seems like an odd announcement to make...if it's just one more step in the research process and this doesn't make graphene a viable replacement *yet*...
It's about the research funding and securing more... They must be out of money so they need to go out hawking their wares to secure more R&D funding.
> Most audio systems out there cannot reproduce much above 16Khz
Don't you mean 20 Hz ??
i.e. http://www.avsforum.com/t/8102...
Way back in the 80's, Popular Electronics published a series of articles that described an active crossover that split 150Hz (or so) off and sent it out a separate output to drive a sub-woofer. They also had two designs for a ported enclosure that used either a 18" or 22" JBL driver. The smaller of the two, which was as big as a coffee table, required 200W and would get you down to about 30Hz on it's own or with equalization you could get down to 20 Hz. The 22" driver design was about 50% bigger enclosure and it would get you down to 16Hz with equalization and about 400 Watts. Always dreamed of doing this and I kept the articles all these years. Now days, you cannot buy the drivers and active crossovers are really cheap so why build your own?
But who needs 20hz? That's more earthquake you feel than sound you hear. Most stereos are going to roll off the low end someplace above 60Hz. The size of the speaker enclosures and the power required start to get really large, really quick as you go much under 100Hz. To do 20 Hz properly is going to take a really large enclosure and a large speaker (something like 18" or bigger) and you will need quite a bit of power (300 Watts or so for 100 Wat stereo) to get a flat response from 100Hz down to 20Hz. But this is WAY below what most stereo systems can do.
But, I'm claiming that nobody really cares about anything below about 100Hz. There is very little material that you can find that uses much below 100Hz beyond action movies and some specialized recordings. (I have some of these recordings). Nobody has equipment capable of reproducing such low frequencies, so in order to avoid 60 Hz hum issues they just cut everything below about 100 in the studio. I'm also claiming that most material doesn't have much content above 16Kzh either, mainly because nobody can hear it and most stereo systems cannot reproduce it. Most recording studios just EQ away anything above 18Khz and below 100Hz just before they compress the life out of their recordings anyway, especially for any material like Country, Rock, Pop, Jazz (less so) that goes out over the radio. Classical is *sometimes* left alone, but in my experience the recordings are usually not done in studios and usually there are significant deficiencies in microphone selection and placement not to mention issues from the acoustics of the venue. My point being, that there is extremely limited material out there where anybody could tell the difference between 20-20Kz system and a 100-18Kz system and of that material, very little of it is anything you'd be willing to listen to in the first place.
There are people who insist that they can hear the difference
They are fooling themselves if they think they can tell which was recorded with the higher bit rate. What they MIGHT be able to hear are the trans-coding artifacts, but in most cases, I'll bet they really are just hearing the limitations of their equipment (distortion products) caused by encoding/decoding artifacts that are outside their ability to hear.
Sorry, that is bullshit!
Not exactly. Most audio systems out there cannot reproduce much above 16Khz or below 60Hz. Your average amplifiers and speakers are going to be rolling off pretty badly at 16Khz so even if YOU could hear stuff above 20Khz, it won't be coming from your speakers trying to reproduce the material. You might be hearing distortion products that high, but I doubt it. Headphones tend to be a bit better on the high end, but even then the average starts to roll off at 20Khz but most of us simply cannot hear above 20Kzh, ever.
Human hearing rolls off pretty badly above 18Khz, even for the young. It's worse when you get older. And I dare say that you know NOBODY who can hear much above 25Khz and if they do they are under 25 years old. Nobody is going to hear 30K, so I have no idea how you think you can hear 100K. What you MIGHT be hearing is distortion products caused by your equipment trying to reproduce material above 20K, but these products will be BELOW 20K and are actually DISTORTION not really the material.
So your point is correct in part, just not for the reasons you suggest. I'll bet you cannot hear above 25Khz (20Khz if you are over 30) measured using a pure single frequency sine tone no more than 10dB louder than a minimum discernible 1Khz pure tone. Higher sampling rates really only matter when transcoding between sampling rates, which points to the ONLY real reason you would like to over sample beyond the Nyquest rate for the highest frequency you can hear. What's more, I'll bet that while you MIGHT be able to hear a difference, you won't be able to reliability tell me which material was recorded at a higher sample rate if you let me choose the material. In fact, I'll bet I can get you to prefer the lower sample rate more often than not.
"cannot tell the difference" -- that's not what is being said here. Instead, the violinists were asked which ones they preferred. Certainly they could distinguish between them.
One would assume that a preferred violin would be the one that was both easy to tune, play and sounded the best. I'm personally surprised that the older ones where not the preferred ones, but if you think about it, it sort of makes sense.
Can you play with the other hand too?
Wow! Stereo!