Not explicitly, but I wanted to avoid a discussion involving the absorption of sunlight by air (e.g. low pressure on a mountain top). As a physicist I don't see how air pressure variations in the range 80-110 kPa would have any measurable effect on the PV efficiency, assuming all other parameters being kept equal. The same for 'humidity' which you mention in this post.
And I have yet to see an inverter last for more than 5 years without any sort of defect
Maybe you have been unlucky. I have a small (600 Wp) PV system on the roof, which is 12 years old now, without inverter problems. So, there is my anecdote.
The insolation values used are questionable.
I assume that you refer to the 1700/1000 kWh/year for South and Middle Europe? According to the official EU data for insolation, this doesn't look unreasonable. Why do you think it is? (Note: the insolation on that map is per horizontal square meter; for example at 1510 kWh/(m2 a) insolation in Northern Spain, an inclined solar panel will do 1730 kWh/(m2 a) and a 2-axis tracking panel will do even 2240 kWh/(m2a).)
panels are actually made in South-East Asia where dirty coal plants without air filters are still in common use.
That may be possible, but that is not the point of our discussion. I appreciate that you have taken the time to clarify your original unreferenced statements, but I still see handwaving arguments that I cannot argue aboutg, such as:
You know very well what I mean.
Obviously temperature is the most important factor, and even that one is often left out of the equation when they do these sort of calculations
the efficiency of the manufacturing process is also significantly lower
And I won't [provide a reference] for the simple reason that you'll just claim my source is invalid.
Maybe because you know yourself that the source is invalid? What kind of argument is this?
I have yet to see a proper counter argument based on independent data from somebody with an EE degree (solid state physics will do as well).
Well, I do have a Masters degree in solid state physics, a Ph.D. degree in spectroscopy, and I work in the semiconductor industry. But I do not claim that I have in-depth knowledge of the economics of the solar-cell industry. Your statement that it depends on air pressure (separately from the amount/quality of sun light) makes no sense to me. The performance of GaAs cells is not relevant in this discussion because they are not used to compete with conventional power plants.
I have no idea where I read the analysis in 2003, but this is what a minute of Google provides today:
US DOE: What is the energy payback for PV? - Energy payback for current thin-film modules is 3 years (including frame, mining, transportation, and so on) "Based on models and real data, the idea that PV cannot pay back its energy investment is simply a myth"
Energy Payback of Roof Mounted Photovoltaic Cells with an overview of different estimation methods, and discussion of how to account for the human labor involved. Most estimates are a couple of years, but indeed, there are estimation methods that will lead you to large values, e.g. if you assume that single-purpose concrete structures have to be erected to mount the PV cells, and that it is a one-off project involving a large amount of engineering.
"Look up how much energy is used to produce one square centimetre of a solar panel."
This argument gets really old. Maybe you can provide that number yourself, with a reference. The 1st time I looked it up (ca 2003), energy parity was reached in 1-2 years depending on the local insolation.
Android phone or not, but there are alternate keyboard layouts, there is probably a dvorak one.
Yes, Android (htc flavor), but I don't see the advantage of Dvorak when I type using only my right index finger. I tried it once, but with that implementation, I lost word prediction and letters with diacritical marks got much harder or even impossible to enter.
Better use a real corpus rather than an arbitrary text from your Books directory, e.g. http://www.wordfrequency.info/files/entriesWithoutCollocates.txt .
I ran some perl scripts over them, with the following results (all weighted by word frequency), single-handed words and words with alternating 4-letter sequences:
Note: the dvorak-"X" and the qwerty-"B" keys are assigned to the left hand. Clearly, with Dvorak you get about 40% fewer single-hand words and twice as many words with alternating sequences.
You would really want to define some merit function that takes into account the cost of moving fingers from the home row and jumping (top row to bottom row), repeated letters, strength of the fingers, and so on. I'm sure someone else has done that already, though. And here in this discussion we won't be able to agree on the merit function anyway.
I'm inclined to think that Dvorak would be mean more RSI
And I decided to switch to Dvorak because I had severe RSI (pain in the forearms and hands, couldn't use a keyboard for more than one minute at a time for several weeks and needed half a year to recover fully) and never had such serious problems again. That said, I also changed my posture, adjusted the armrests, and moved the Ctrl to the caps-lock position. Nowadays, if I have to operate a computer for as little as an hour on a desk that is 5 cm too high, my shoulders hurt like crazy. With dvorak I do get problems with my pinky finger after long sessions involving a lot of \{} characters.
Well, anecdote versus anecdote.
86wpm on the Astronaut text
86 wpm here too, and 93 for Aesop. Both Dvorak. Astronauts on Qwerty is 55 wpm (lots of time wasted correcting typos), but I rarely use Qwerty these days (mostly on my phone).
Intel might be the only company that can justify 450mm wafers.
As another poster mentioned, Intel is not the only one who wants 450 mm wafers. A big part of the cost of wafer processing is proportional to the number of wafers and not on the surface area; that's why a transition to 450 mm will lead to cost reduction. This cost aspect actually doesn't apply for ASML's lithography tools (or so I believe), since the tool throughput (wafers per hour) is roughly inversely proportional to the wafer surface area. The throughput depends largely on how fast you can move wafers around with nanometer-level accuracy (does not get easier with a bigger wafer) and how much light power is available (which doesn't depend on the wafer size).
Disclosure: I work in ASML's R&D department (not on the 450 mm stuff), but the above views are my own.
As a Dvorak user since 16 years I'd like to mentinon can add an anecdote: my typing speed did not go up by much (back then I could do about 400 characters per minute on Qwerty, nowadays it's 480 on Dvorak). But the strain on my fingers decreased tremendously. Dvorak is not particularily pleasant for C and LaTeX with locations of the \{} keys, though.
... placing commonly used keys far apart, as with the QWERTY, actually speeds typing, since you frequently alternate hand
That's correct in a way, but not really an argument in favor of Qwerty above Dvorak, since Dvorak is actually much better in that respect than Qwerty.
These could be leveraged further to give its x86 chips a boost vis-a-vis ARM. The other players need to pull their act together & pool resources to counter this.
Not necessarily. Once ASML has developed these technologies, they will be sold to all customers on equal terms. Moreover, unlike normal shareholders, Intel will not have voting rights and can therefore not easily influence the strategy of ASML. ASML's only obligation is that the R&D investment is allocated to development of said technologies. Other ASML customers (Intel competitors) are welcome to take a share in ASML on similar terms, so similar announcements from the competition may come during the next few months. You may want to read the official press releases.
You may be interested to know that ASML has 82% of the lithography market (by revenue), with equipment installed at most if not all manufacturers of CPUs and flash/DRAM memory. The semiconductor industry is driven by Moore's law; in a way, they are dependent on how fast ASML can develop equipment to produce ever smaller features. The interest of the ASML customers in this customer co-investment program is not so much in a competive advantage against each other, but rather to keep up with Moore's law.
Disclaimer: I work for ASML (in R&D), but the views above are my own, etc.
Consider this when you hear that non-smokers exposed to second-hand smoke are 20% more likely to get lung cancer.
I think you missed this part:
The only time you can take small changes seriously is when there are multiple sources and a proposed mechanism that is consistent with our previous understanding.
In the case of passive smoking, there are ample studies confirming effects on lung and cardiovascular diseases, and the mechanism is pretty clear as well. The Wikipedia article mentions risk increases for heart disease and lung cancer between 20% and 60% (Unfortunately I don't have time now to read the references, to see under which conditions these numbers are valid).
"current distance to Alpha Centauri (give or take a couple inches i'm sure), would take over 2 trillion years to bridge the space in between"
You made an error in your calculation. Since 20 km/s is 1/15000 of the speed of light, it would take 15000*4=60000 years to travel 4 light years, which is quite a bit less than your number.
Replying to myself: of course, I realize that the OP cannot use a hard-link backup if the usb drive cannot hold all his important data. It's too long ago that I used rdiff-backup; can you reliably split the master backup and the differential backups to different filesystems (say the drive at home and the usb stick)? Preferably without risking corrupted backups if it involves manually merging diff trees.
Or he could save himself a ton of grief and just use rdiff-backup,
Interesting, since I used rdiff-backup in the past and found it a pain. If files are stored as diffs of diffs of diffs of diffs of a full copy, it is rather easy to corrupt the backup. These days, I make backups using rsync, with
For the first backup, omit the --link-target argument. Only modified files are stored. As long as you don't have tons of big files that have only a few bytes changed, I don't see the advantage of rdiff-backup. However, it requires that the backup filesystem supports hard links (see my other comment on the use of a unix filesystem on a flash drive). When you come back home, you can do something similar (with --delete) to sync back to your regular backup drive.
The modify-window option is there to because I have to backup Windows filesystems as well.
If you go for a system where the files are stored in a Unix-like filesystem (case-sensitive filenames, permissions), what kind of filesystem would you need to use on the USB stick? I believe that the wear-leveling system on USB sticks and flash cards is optimized for FAT filesystems (with the file allocation table right at the beginning). I think that a journalling filesystem would be a good idea on a flash drive, which leaves you with ext2 (with noatime) and very long filesystem checks every time you accidentally pull out the USB stick without unmounting.
With backup drives and file transfers, I also tend to run into the problem that I have different UIDs on different systems. Maybe not such a problem for the OP, but you mention backups of/var which is typically full of files owned by system users (e.g. cups, and mysqld/apache if you use the laptop for web development).
You don't think JAXA has a large team of experts? They work with universities and have their own highly educated staff,
Like with the research on nuclear-fusion energy and space elevators. I'm not completely against doing some research in those fields, since in case of success, the payoff would be huge. But I wouldn't bet on it, since the technical hurdles are huge, in all of these three fields.
hilarious about these blog posts is how they assume that somehow their few hours with a pen, paper and Google has somehow uncovered a huge flaw in a plan that academics
There's no link on the web site to any supporting institutions, grants, or anything like that, even though the summary twice mentions the Max Planck Institute.
whois crpt.me results in:
Registrant Name:Sergej Flach Registrant Address:Noethnitzer Str. 28 Registrant City:Dresden Registrant State/Province:Saxony Registrant Country/Economy:DE Registrant Postal Code:01187 Registrant Phone:+65.03267603
At least, it is one of the authors and the address matches the Max Planck institute. I'm not sure whether a.me (Montenegro) domain requires proof of identity, though.
Detecting gamma rays on a flat sensor is one thing. But how do you actually image gamma rays? You cannot use a lens or curved mirror. A cursory check on google/Wikipedia does not answer this. I can only think of a pinhole camera, which is very inefficient and would have to deal with radiation passing through the supposedly opaque walls.
"Since small impurities in *pure* water make a huge difference in the freezing point, but bugger all difference in brine,"
The freezing point depression of water is 3.7 K for every mol/l of dissolved salt (assuming two mol ions per mol salt). Adding the same impurity to the saturated brine will lower the freezing point by the same amount as for pure water. Moreover, medium hard water is about 1 mmol/l, so it's just a few mK error anyway.
Do these forensic extraction devices really work on an arbitrary phone, or only if the phone is configured to go into usb debug mode as soon as a usb cable is plugged in?
My Android phone defaults to "usb charge only". I find it difficult to believe that a special usb host would be able to take control over the phone.
[incandescent bulbs] didn't use as much power as the CFLs do (I'm including the power to ship from China & drive them to the landfill).
One 12 W CFL, equivalent with 60 W incandescent, over 5000 hours: electricity savings = 225 kWh = 800 MJ electrical energy = 2 GJ heat of combustion in a power plant.
Equivalent car fuel @ 35 MJ/liter: 57 liters (15 gallons). How far do you live from the landfill?
Let 0s be room temperature and let 1s be somewhat below room temperature.
Yes, the memory will absorb heat, but it costs heat from the hot room. You have to consider the total energy of a closed system and it your naïve approach, the best you can get is a net neutral energy balance. The argument is primarily about the fundamental increase of entropy associated with erasing a bit, and thermal equilibration (between a hot and a cold object) definitely represents an increase in entropy.
assuming you meant to write parentheses (xdist*xdist), if the particle coordinates are (0,0) and (0,1), then xforce would become infinite. you'd need something like
xforce = g*mass1*mass2*xdist / pow(xdist*xdist+ydist*ydist, 1.5)
Slashdot Mirror
Not explicitly, but I wanted to avoid a discussion involving the absorption of sunlight by air (e.g. low pressure on a mountain top). As a physicist I don't see how air pressure variations in the range 80-110 kPa would have any measurable effect on the PV efficiency, assuming all other parameters being kept equal. The same for 'humidity' which you mention in this post.
Maybe you have been unlucky. I have a small (600 Wp) PV system on the roof, which is 12 years old now, without inverter problems. So, there is my anecdote.
I assume that you refer to the 1700/1000 kWh/year for South and Middle Europe? According to the official EU data for insolation, this doesn't look unreasonable. Why do you think it is? (Note: the insolation on that map is per horizontal square meter; for example at 1510 kWh/(m2 a) insolation in Northern Spain, an inclined solar panel will do 1730 kWh/(m2 a) and a 2-axis tracking panel will do even 2240 kWh/(m2a).)
That may be possible, but that is not the point of our discussion. I appreciate that you have taken the time to clarify your original unreferenced statements, but I still see handwaving arguments that I cannot argue aboutg, such as:
Maybe because you know yourself that the source is invalid? What kind of argument is this?
Well, I do have a Masters degree in solid state physics, a Ph.D. degree in spectroscopy, and I work in the semiconductor industry. But I do not claim that I have in-depth knowledge of the economics of the solar-cell industry. Your statement that it depends on air pressure (separately from the amount/quality of sun light) makes no sense to me. The performance of GaAs cells is not relevant in this discussion because they are not used to compete with conventional power plants.
I have no idea where I read the analysis in 2003, but this is what a minute of Google provides today:
"Look up how much energy is used to produce one square centimetre of a solar panel."
This argument gets really old. Maybe you can provide that number yourself, with a reference. The 1st time I looked it up (ca 2003), energy parity was reached in 1-2 years depending on the local insolation.
Yes, Android (htc flavor), but I don't see the advantage of Dvorak when I type using only my right index finger. I tried it once, but with that implementation, I lost word prediction and letters with diacritical marks got much harder or even impossible to enter.
Note: the dvorak-"X" and the qwerty-"B" keys are assigned to the left hand. Clearly, with Dvorak you get about 40% fewer single-hand words and twice as many words with alternating sequences.
You would really want to define some merit function that takes into account the cost of moving fingers from the home row and jumping (top row to bottom row), repeated letters, strength of the fingers, and so on. I'm sure someone else has done that already, though. And here in this discussion we won't be able to agree on the merit function anyway.
And I decided to switch to Dvorak because I had severe RSI (pain in the forearms and hands, couldn't use a keyboard for more than one minute at a time for several weeks and needed half a year to recover fully) and never had such serious problems again. That said, I also changed my posture, adjusted the armrests, and moved the Ctrl to the caps-lock position. Nowadays, if I have to operate a computer for as little as an hour on a desk that is 5 cm too high, my shoulders hurt like crazy. With dvorak I do get problems with my pinky finger after long sessions involving a lot of \{} characters.
Well, anecdote versus anecdote.
86 wpm here too, and 93 for Aesop. Both Dvorak. Astronauts on Qwerty is 55 wpm (lots of time wasted correcting typos), but I rarely use Qwerty these days (mostly on my phone).
As another poster mentioned, Intel is not the only one who wants 450 mm wafers. A big part of the cost of wafer processing is proportional to the number of wafers and not on the surface area; that's why a transition to 450 mm will lead to cost reduction. This cost aspect actually doesn't apply for ASML's lithography tools (or so I believe), since the tool throughput (wafers per hour) is roughly inversely proportional to the wafer surface area. The throughput depends largely on how fast you can move wafers around with nanometer-level accuracy (does not get easier with a bigger wafer) and how much light power is available (which doesn't depend on the wafer size).
Disclosure: I work in ASML's R&D department (not on the 450 mm stuff), but the above views are my own.
As a Dvorak user since 16 years I'd like to mentinon can add an anecdote: my typing speed did not go up by much (back then I could do about 400 characters per minute on Qwerty, nowadays it's 480 on Dvorak). But the strain on my fingers decreased tremendously. Dvorak is not particularily pleasant for C and LaTeX with locations of the \{} keys, though.
That's correct in a way, but not really an argument in favor of Qwerty above Dvorak, since Dvorak is actually much better in that respect than Qwerty.
Not necessarily. Once ASML has developed these technologies, they will be sold to all customers on equal terms. Moreover, unlike normal shareholders, Intel will not have voting rights and can therefore not easily influence the strategy of ASML. ASML's only obligation is that the R&D investment is allocated to development of said technologies. Other ASML customers (Intel competitors) are welcome to take a share in ASML on similar terms, so similar announcements from the competition may come during the next few months. You may want to read the official press releases.
You may be interested to know that ASML has 82% of the lithography market (by revenue), with equipment installed at most if not all manufacturers of CPUs and flash/DRAM memory. The semiconductor industry is driven by Moore's law; in a way, they are dependent on how fast ASML can develop equipment to produce ever smaller features. The interest of the ASML customers in this customer co-investment program is not so much in a competive advantage against each other, but rather to keep up with Moore's law.
Disclaimer: I work for ASML (in R&D), but the views above are my own, etc.
I think you missed this part:
In the case of passive smoking, there are ample studies confirming effects on lung and cardiovascular diseases, and the mechanism is pretty clear as well. The Wikipedia article mentions risk increases for heart disease and lung cancer between 20% and 60% (Unfortunately I don't have time now to read the references, to see under which conditions these numbers are valid).
"current distance to Alpha Centauri (give or take a couple inches i'm sure), would take over 2 trillion years to bridge the space in between"
You made an error in your calculation. Since 20 km/s is 1/15000 of the speed of light, it would take 15000*4=60000 years to travel 4 light years, which is quite a bit less than your number.
"In some places, like where I live ... However, Bing Maps is the best one of them with most information"
And where is that place where you live? Sorry, I get suspicious if a newish user account promotes Bing like that.
Replying to myself: of course, I realize that the OP cannot use a hard-link backup if the usb drive cannot hold all his important data. It's too long ago that I used rdiff-backup; can you reliably split the master backup and the differential backups to different filesystems (say the drive at home and the usb stick)? Preferably without risking corrupted backups if it involves manually merging diff trees.
Interesting, since I used rdiff-backup in the past and found it a pain. If files are stored as diffs of diffs of diffs of diffs of a full copy, it is rather easy to corrupt the backup. These days, I make backups using rsync, with
For the first backup, omit the --link-target argument. Only modified files are stored. As long as you don't have tons of big files that have only a few bytes changed, I don't see the advantage of rdiff-backup. However, it requires that the backup filesystem supports hard links (see my other comment on the use of a unix filesystem on a flash drive). When you come back home, you can do something similar (with --delete) to sync back to your regular backup drive.
The modify-window option is there to because I have to backup Windows filesystems as well.
With backup drives and file transfers, I also tend to run into the problem that I have different UIDs on different systems. Maybe not such a problem for the OP, but you mention backups of /var which is typically full of files owned by system users (e.g. cups, and mysqld/apache if you use the laptop for web development).
Like with the research on nuclear-fusion energy and space elevators. I'm not completely against doing some research in those fields, since in case of success, the payoff would be huge. But I wouldn't bet on it, since the technical hurdles are huge, in all of these three fields.
Well, this blogger is actually an associate professor in the physics department at UCSD, and a member of CASS, the Center for Astrophysics and Space Sciences..
whois crpt.me results in:
At least, it is one of the authors and the address matches the Max Planck institute. I'm not sure whether a .me (Montenegro) domain requires proof of identity, though.
Detecting gamma rays on a flat sensor is one thing. But how do you actually image gamma rays? You cannot use a lens or curved mirror. A cursory check on google/Wikipedia does not answer this. I can only think of a pinhole camera, which is very inefficient and would have to deal with radiation passing through the supposedly opaque walls.
"Since small impurities in *pure* water make a huge difference in the freezing point, but bugger all difference in brine,"
The freezing point depression of water is 3.7 K for every mol/l of dissolved salt (assuming two mol ions per mol salt). Adding the same impurity to the saturated brine will lower the freezing point by the same amount as for pure water. Moreover, medium hard water is about 1 mmol/l, so it's just a few mK error anyway.
http://en.m.wikipedia.org/wiki/Freezing_point_depression
Do these forensic extraction devices really work on an arbitrary phone, or only if the phone is configured to go into usb debug mode as soon as a usb cable is plugged in?
My Android phone defaults to "usb charge only". I find it difficult to believe that a special usb host would be able to take control over the phone.
I think you have to double-check your math. A factor 4.5 in lifetime cannot result in a factor 15 in equivalent fuel usage.
One 12 W CFL, equivalent with 60 W incandescent, over 5000 hours: electricity savings = 225 kWh = 800 MJ electrical energy = 2 GJ heat of combustion in a power plant.
Equivalent car fuel @ 35 MJ/liter: 57 liters (15 gallons). How far do you live from the landfill?
Yes, the memory will absorb heat, but it costs heat from the hot room. You have to consider the total energy of a closed system and it your naïve approach, the best you can get is a net neutral energy balance. The argument is primarily about the fundamental increase of entropy associated with erasing a bit, and thermal equilibration (between a hot and a cold object) definitely represents an increase in entropy.
quote: xforce = g*mass1*mass2 / xdist*xdist
assuming you meant to write parentheses (xdist*xdist), if the particle coordinates are (0,0) and (0,1), then xforce would become infinite. you'd need something like
xforce = g*mass1*mass2*xdist / pow(xdist*xdist+ydist*ydist, 1.5)