We're interested in anything geeky and technical (at least I am), but you can't squeeze blood from a turnip, or at least not much. So you can talk about products that have new features as long as the features are actually interesting and new. Or you can talk about the features from a technical standpoint, showing what the features really mean, what's important, and what's physically achievable, instead of just rattling off specs like a Best Buy salesman who doesn't understand the product or the specifications.
Taking the Plantronics video as an example, there isn't a whole lot of interesting stuff going on there because they're just making very run of the mill consumer/business products. You could try and squeeze out something good talking about the wireless interface design, or frequency response, noise floor, and distortion in the audio quality, or what makes one headset ergonomic and another uncomfortable, or whether bacteria really grow faster in your ears when you're wearing headphones, just to name a few ideas. But by going with Plantronics you're limiting your options, because their products are fairly boring.
If you want to do a video about computer interface devices you'll have an easier time if you pick something that's already geeky, maybe gaming mice. Then you can get a company that really cares about its products who will tell you about the ergonomics and how their latency and movement accuracy is better than another company's, and they'll have numbers to back it up, and maybe talk a bit about how they accomplished those things. Or talk to monitor manufacturers about new display technologies like OLEDs and 3D, just make sure not to get caught up in marketing-speak. Even better if you could get a monitor manufacturer to HONESTLY discuss monitor specifications like why the contrast ratios are generally BS, how accurate the colors are and how to color calibrate your monitor, and what to look for if you're buying a monitor for watching videos or gaming.
You could also delve into wireless standards, look at all of the different technologies that carriers are calling 4G and what the actual performance of each is and whether it really deserves to be called 4G. Keep an eye on new ultra high speed wireless technologies like Intel WiDi or anything else operating in the 57-64GHz ISM band.
Of course this is just a few of my thoughts about what kinds of information about products are interesting, not about whether it makes a good video. I'm generally not a fan of videos versus static content unless the videos are really well done, or unless you're taking advantage of videos to show something that can't easily be presented in a static page. A big part of that is that videos generally take longer to watch and have less information.
Most areas quite reasonably have building height restrictions so that you can't arbitrarily block neighbor's views or cast shade on their homes/offices by building much taller than an area's prevailing building height. It will not necessarily be trivial to get a building permit to install a tower on top of your roof. And although you can obviously get more power per unit footprint by packing 32 time more solar cells into the tower which is what the researchers did this does not scale up to larger footprints because you will have to space the units out wider so that the towers are not shaded by their neighbors.
The researchers admit in their pre-print (http://arxiv.org/abs/1112.3266) that a full cost analysis (which would determine the actual value of their work) is beyond their preliminary analysis, but that does not stop them from claiming "Our results show that 3D sunlight collection has the potential to serve as a paradigm shift in solar energy conversion toward the Terawatt scale." I'm used to researchers hyping up their work to get funding, but I rarely see such arrogance in a paper.
Their work has some value in exploring solar structure designs that can get the most power in a given installation form factor without using any solar tracking solutions. But even if they do cost analysis on installed cost per average generated kWh their work is clearly incremental, not paradigm shifting.
As far as I know all superconductors have a critical current density, above which point the magnetic field generated in the wire exerts enough force on the electrons that the wire is no longer a superconductor, which means at low voltage to sustain the large currents the wires would need to be much thicker. In-town distribution before transformer conversion to +/-120V is often at around 4kV, the superconducting wire would need 800 times the area to run at 5V. The massive current levels would also result in extreme problems designing fuses and switches for substations, power lines, and customer entry points. It's even harder if the current is DC instead of AC because there is no current zero crossing to help extinguish the arc. Distribution and transmission voltages could certainly be lowered, but there will be problems lowering it by over an order of magnitude which probably outweigh the small number of people who electrocute themselves.
While 9V can be fatal, 40V is a rule of thumb lower safety limit valid under most reasonable conditions. Actual fatal voltages can vary dramatically due to skin resistance varying over orders of magnitude and whether the current path goes close to your heart or not. To be in danger below 40V generally requires (as in your Darwin award) penetration of the skin, or contact over large areas with water.
The simple and necessary action (reviewing, confirming, and releasing the video) was done very shortly after we became aware of the issue -- several hours ago.
Why weren't you already aware of the issue when Rumblefish's claim was disputed the first time? Every time your company makes a fraudulent copyright claim there won't necessarily be a Slashdot story to catch your attention and call you on your mistakes.
Was there even a review process when this was first disputed? Was this a one-off mistake or is your review process inadequate? The bar of standards should be set high when you are claiming ownership over somebody else's content.
Then the GPS industry should buy the spectrum if it's necessary for proper operation of their devices.
You mean the US government? Because they are the ones who own, built, and operate the GPS satellite system and the associated spectrum. It is a critical resource for military, commercial, and personal use, and FCC spectrum regulations have long been in place to prevent interference to satellite bands which involve very low signal levels by the time the signals reach earth.
The "GPS industry" has always had the spectrum that they need, Lightsquared is the one butting in because their transmitters leak interference into the GPS L1 band.
(1) The FCC is not in any way saying that licensed users cannot transmit close to the GPS band. The band Lightsquared is using is intended for satellite-earth transmissions because they will be at similar power levels at ground to the GPS signal and thus will not pose an interference problem. Lightsquared tried to weasel an exception out of the FCC and failed. GPS is a critical system used by millions of people on a daily basis and it is clearly more important than a cellular network that is trying to operate in a band they shouldn't be in.
(2) Better filtering requires a combination of three things: (a) increased size, (b) increased cost, (c) lower quality passband signal (higher attenuation). By making intelligent allocations of spectrum with their oversight the FCC can ensure better utilization of finite bandwidth than if it was a free-for-all and everybody had to install huge expensive filters on their RF front-ends. The FCC decrees that transmitters operating close to the GPS band (and other satellite-earth bands) do so at sufficiently low power levels to avoid interference, which ensures that the millions of GPS receivers can be (a) smaller, (b) cheaper, and (c) higher performance. For very high performance GPS receivers this filtering is very difficult too, because the bandwidth of the GPS receiver is intentionally widened to get more signal. Are you seriously suggesting that the tens to hundreds of millions of GPS receivers in use today need to be replaced with (a) larger, (b) more expensive, (c) lower performance receivers just so that we can all cater to the whims of a startup company that tried to game the system and lost?
I'm not sure if I should bother replying to you as there is a reasonable chance you are astroturfing for Lightsquared, but in case you're not I hope you will consider these issues before spouting off more of these posts which assume Lightsquared is innocent in this (they are not).
In Western theological terms, that's like saying that Christ is an inspirational person with some really interesting teachings, but not the Son of God. That's about as blasphemous as you can get.
You might be right that the place for this tech is a pre-treatment for an RO process, but it isn't mentioned in the article and the researchers appear to be looking for a gadget "where you put saltwater in one side and delicious drinking water comes out the other":
The desalinated water that comes from the battery still contains too much salt for drinking, La Mantia says: “We removed up to 50% of the original salt, but we need to arrive at 98%.”
Doing several cycles of ion removal with the battery would further desalinate the water, but those extra cycles cost energy, so La Mantia hopes to improve the efficiency enough so that the battery can remove the salt in a single pass.
I'd be dubious about the efficiency of doing this electrochemical desalinization to remove so much of the salt, I would think that the resistance of the water is going to rise substantially as salt leaves so it seems like more and more electrical energy will be required per mole of salt ions as the concentration drops.
So by pre-treating water to remove much of the salt before sending it to RO the membranes will last longer before replacement? How much of the operating cost of an RO plant is determined by this? Would there be an impact on the RO process energy consumption?
A lot of times, if you get a TA or RA assistanceship, your tuition is paid and you get a monthly stipend, in effect paying you to go to school.
Although that has been the default for most engineering PhD students, it is getting harder and harder to find funding as a grad student due to universities shrinking their TA budget and government agencies and companies shrinking their R&D budget. Masters students always have a hard time getting funding for grad school because few professors want to pay a student who will be leaving soon anyway and has little experience yet, and universities want to save their TA funding for the students who will be getting PhD's and thus making the university look good.
But for a PhD, it's much worse; it takes even more time than the MS (compounding those interest and no-pay factors), and you don't get any more salary for it except for a few select disciplines, and in fact it'll disqualify you from a lot of jobs because they'll think you want more money (which you will), and they don't want expensive workers, they want cheap ones.
Since the original article is about R&D, I'm assuming we're talking about STEM (science, technology, engineering, math) PhD's, in which case you most certainly earn more once you have the degree. Of course somebody with a lesser degree and more experience might make a similar amount, but the same person with a higher degree will generally be paid more. And yes it disqualifies you from (or at least makes it harder to get) low-level jobs, because the company rightly assumes a PhD would be unhappy doing low-level work and would quit for a better job.
Generally, PhDs in engineering fields (and most others) are only useful if your career goal in life is to become a university professor.
Most engineering PhD's go into industry either in the field of their PhD or into new fields. Becoming a university professor is actually a very challenging and competitive career path, since a university professor is expected to be both a leader in research and teaching. Of course there are still other academic jobs such as assistant/associate prof, lecturer, and there are non-PhD granting colleges which are easier academic jobs, but still most PhD's are happy to leave academia for the higher paid and less stressful industry jobs.
I thought the orangeish color was there because sodium vapor lamps are a cheap compact high-power bulb technology. White HID bulbs using rare earth metals to emit more colors are more expensive.
just wait legos will be pirated very quickly i know that if i had a 3d printer i sure would print them.
In order to make lego bricks which both hold together firmly and can be easily pried apart requires precision injection molding http://entertainment.howstuffworks.com/lego1.htm, http://en.wikipedia.org/wiki/Lego#Manufacture. 3D printers don't have the tolerance, material strength, nor finish quality required for producing strong tight-tolerance pieces like this. Printing is just a fundamentally different manufacturing process which is good for certain tasks but not this kind of task.
There are stereolithography machines which do additive manufacturing by curing a photosensitive polymer one layer at a time, and these can be quite precise. However they are slow and very expensive to run. They are useful for some specialized tasks like building structures which could not be machined in a single piece using traditional machining equipment due to internal structures. There is little choice of material though as you are limited only to liquids that are photo-curable and you only get to choose one material for a given solid piece. There's no manufacturing revolution here, it's a specialized piece of equipment which produces small quantities of parts at a high price. Useful for prototyping and specialized tasks, not mass production.
I wonder how would a young 21 year old academic with ALS fare in the USA.
US universities generally have great benefits for their employees (good health insurance policies) and tend to be pretty flexible with sick leave for professors
21 year old academics (even Stephen Hawking) are not professors, they are undergrads or grad students, and they do not get professor-level health insurance plans from the university. I'm a grad student on my university's health insurance policy, it's not bad at least for routine care although the co-pays are higher than when I was on my parent's plan. It costs me a little over $2,200/year, which is admittedly much less than tuition. Sidenote: thanks to "Obamacare" it is much easier for kids to stay on their parents health insurance plan to an older age (26 I think?), which is great if (A) your parent has a job with health insurance and (B) putting you on your parents plan doesn't cost more than you and your parent can afford.
The better question would be how would a young blue-collar worker with ALS fare. He would be completely screwed.
T-Mobile has been offering discounted no-contract plans if you bring your own phone for at least two years now, which is when I first got one of these plans. The T-Mobile Value plan for individuals with 500 minutes, unlimited texts, and 2GB of data for $50/mo is essentially equivalent to my current plan which is no longer offered on the website. It is also pretty similar to the Monthly4G prepaid plans from T-Mobile.
Of course the next issue is that of compatibility. There are so many radio bands and communication standards to cover in the USA that when you buy your own phone you have to do a bit of extra research to make sure your phone is compatible with your intended network's high speed data options.
I wrote up a little section on why wearable organic transistors are not well suited for any real digital computation to add on to your post (longer physical propagation delays, extremely slow FETs, high resistance interconnect, uneven/changing surrounding dielectric environment), but then I read the paper and realized that it's just the poor journalism at ExtremeTech that was talking up that angle. The actual researchers don't mention high power digital circuits like ExtremeTech, in fact the only application I saw that the paper directly mentioned was chemical and biological sensors.
The actual computing horsepower for wearable computers with any real complexity will obviously need to be provided by conventional CMOS chips for years to come. They are tiny and can be integrated in clothing with little impact and easily ruggedized for washing machines, they use far less battery power, they are reliable, and can actually provide real computing power. The place for integrated organic semiconductors in wearable computing is for things like displays and sensors which don't need high speed transistors but need large areas, flexibility, or interesting chemical properties. There is undoubtedly going be a place for very simple circuits directly implemented in organic textile based transistors, but it's not going to power a GPS receiver or anything fancy like that.
This is a well-known consideration when using bodies of water for cooling, and I'd be surprised if the environmental impact review for this project failed to do the calculations and address this issue. It's part of the discussion here. Some power plants even need to decrease their output power when outdoor temperatures rise in order to comply with regulations on how much heat they can dump into their sources of cooling water.
It's actually not particularly difficult these days to create a compact and cheap boost converter, chips are available with everything included but the external inductor and coupling capacitors. Inductors can be large, but nowadays it's easy to find very compact SMT inductors. The efficiency may not be great due to higher resistance and core loss but it can be made quite cheaply and compactly.
Although the article claims to be talking about a silicon *transceiver* running at *300+GHz*, the graphics included in the article just have a planar horn antenna and a diode on an InP substrate all connected up to a SMA connector. A bit disappointing to be honest. No mention of whether they're using the diode as a detector or mixer (or both), but the pieces they are talking about appear to be a long ways away from an actual communication system.
One of the big problems faced in reality will be getting enough power to overcome the high losses at THz frequencies, particularly if they are eschewing LNA's and PA's at the front end and using the diodes for up-/down-conversion. Given the simplicity of the front-end it will require a lot more complexity and high-power in the back-end circuitry which they make no mention of solving. And if they are using some high-harmonic mixing with that diode then they're probably not going to meet regulatory emission requirements using just the antenna structure to filter out radiation of the spurious mixing products.
I've never suspected students of cheating during exams, but I do notice it when grading homeworks and two students who turn in their homework assignment one after another have identical wrong answers, or answers identical to the solutions manual which any determined student can usually get.
Most of the time I did not take action when I suspected it, due the lack of complete certainty, the hassle you describe, and the fact that many professors did not encourage taking it seriously since the test scores were weighted more heavily anyway.
I did take action a couple of times. One time I was certain that a pair of students had copied from the solutions manual (it was a handwritten manual easily available as PDF online, both students had incorrectly transcribed a smudged section in a nonsensical way that made perfect sense if you had the solutions manual in front of you), so I gave them both zeros on the full assignment with a note not to copy from the solutions manual. Didn't hear a peep from either one when they collected their homework. The other time was a take home final where two students had liberally used each others' work (shoddy work I might add). When I let the prof know he just asked me to send a warning email (way to take action Prof. ______!) and so I did that and cut the two students' points in half.
This is anecdotal, but I have worked in defense contracting companies and there I was an "exempt" employee, meaning that I wouldn't get paid overtime if I go over 8 hours in a day, or 40 in a week though I was paid straight time if I worked late. I would take my lunch whenever I felt like it as nobody was checking on when or if I did. As I would set my own schedule within reason based on current projects and deadlines, I would sometimes end up working very long or short hours as necessary.
Then again I was working in R&D, it wouldn't surprise me if there are more specific rules for skilled manual labor as they probably don't want a welder working 12 hour days or skipping meals until he's tired and makes an expensive or dangerous mistake. Sometimes things like this can also a result of specific union rules.
My guess for a situation like welding on a nuclear submarine is that management and the military want to dot the i's and cross the t's as precisely as they can in terms of following laws and procedures so that if something does get screwed up on the sub or an employee gets injured they don't want anybody to be able to point a finger at the labor practices of management.
This will never get funded, of course -- it isn't "big science" in any visible way
DARPA does love crazy game changing ideas like this... but you'll have a tough time getting this one past a technical review since you appear to be unaware of some serious technical issues.
Every cell phone tower is basically a big antenna.
It really isn't. A cell phone tower is a just a tower with many directional antennas on it. Typically antennas are installed in a trio each one covering 120 degrees, to separate the three "cells" the tower covers. Each antenna has its gain focused on the ground level where the customers are located. The gain straight up will be terrible. Because of this direction you'll be raising the noise temperature of the antenna dramatically because its picking up thermal noise from the hot ground, which will hurt your sensitivity quite a bit.
Then there are issues like sidelobe mitigation (which you can't do since the towers are fixed), radio interference (these are cell phone towers after all), actually getting the phase between multiple towers synchronized (not as easy as you think), the cost will be far higher than your student's guess (you'll need your own RF hardware, the cell phone receivers won't cut it), and the tower operators and antenna operators aren't going to be nearly as accommodating as you assume.
Of course, if this is true then I guess I'll soon have somebody knocking on my door for publishing this on/., but so be it.
You are correct, there is a definitive minimum energy required to split up a water molecule and get out hydrogen and oxygen. This energy is the same as the potential energy that would be released if you burned the two gases together in an exothermic reaction, getting the water back. Typically though electrolysis uses much more energy than that, because there is a certain "activation energy" threshold that you have to reach before the reaction can occur. Without a catalyst you have to put in extra energy to get over this barrier, and the extra energy left over at the end turns into heat. If splitting the water molecule is like pulling a weight a certain height up a hill (in terms of potential energy), the activation energy is an extra hump you have to pull the weight over, after which the weight is free to roll back down to the final height. See this illustrate here: activation energy plot.
So a catalyst does not let you get energy for free, but it lets you turn electrical energy into chemical energy of hydrogen and oxygen with less wasted energy.
You are jumping the gun quite a bit with your proclamation I think. Google+ is still a very new product, Google is doing fine as a company and will not dump this attempt because they got scared after less than 6 months of operation. Plenty of people, including myself, use it in addition to Facebook, and some people I know use it instead of Facebook. Maybe your social group doesn't use it, but that's their choice. It makes a lot of sense for Google to have a social media platform at their disposal as people spend so much time on social media sites, and they need eyeballs to sell ads. I have never been pissed off or suspicious about Google's intentions with Google+. So no, Google+ is not a failure and we won't be able to say it is for some time.
Side note: I don't understand why you think a Google+ failure would leak over into other services like Gmail. Gmail is still a very distinct service from Google+.
in terms of hard infrastructure, everything has already been paid for. There's no 'state-provided' street or sidewalk on which this business is taking place, nor a state-built thoroughfare upon which a consumer has to travel to visit a store. Yes, the US gov't invented the internet, but for at least the last dozen years every iota of bandwith on which our (consumer's) signals travel is paid for commercially, and the costs passed down to either we the consumers (through our ISPs) or the businesses (through their providers)
You are correct sir! The datacenters hosting the websites selling you products online are floating in the sky, not a building on a public road. Similarly, the warehouses from which these products are shipping and the offices housing the people who run and manage the company are floating in the sky. There are no trucks that ship the products to you on public roads because physicists have perfected teleportation, but are currently only licensing it to online retailers.
whatever actual physical location a business has somewhere, the services that they consume (fire, police, etc.) from the government are already paid for in their property taxes.
This appears to be an argument against all sales tax rather than merely against online sales taxes, by saying that everything can be paid for from property tax. One might argue that it would be a more regressive tax, because in a store (online or brick-and-mortar) selling luxury or high-end products the ratio of the value of the annual transactions to the value of the property would be much higher for luxury items. It would also make the progressive exceptions to sales tax on groceries that many (all?) states implement very complicated to lay out in the property tax code.
Self-evidently there's no need for police services for the sorts of store loss-prevention actions (shoplifters, etc) for internet stores.
Yes, no crime or theft ever took place in a shipping warehouse, or on the roads that shipments travel on, but brick-and-mortar stores are wretched hives of scum and villainy (/sarcasm). Maybe there are different levels of crime, but at most that would suggest a sales tax discount for online sales, not elimination.
In short, simply because the government needs money, and can take it, doesn't mean we need to tolerate it blithely like sheep.
In 22 of the 50 states (according to Wikipedia), internet sales are already taxed as a "use tax" but many people do not report it on their state tax return, essentially committing tax fraud. Having online retailers collect the tax is simply a more effective way of collecting an existing tax, at least in those 22 states.
To put the government's argument quite simply: The states and counties had a source of tax revenue with which to provide government services. Parts of this revenue were lost due to online shopping that goes untaxed. The level of services that the taxpayers want from the government is mostly unaffected. The choice is then to collect more taxes in some other way, cut government services, or go into debt. It's so easy to say that government is wasteful and spending should be cut, but it's incredibly hard to run an organization the size of the government efficiently and the government does do a lot of useful things for us that wouldn't happen without taxes.
The video you link appears to be a DIY stereolithography machine. These machines are very nice and create 3D parts with extremely high resolution. I have seen the output from one of these machines at a company I have worked out, the resolution is better than 100um and the parts that it produced needed no additional machining (in fact they were producing parts that could not have been produced in a single piece by machine). However the machine itself cost over $100k, and the resin costs $100's per liter. It makes a lot of sense for high end prototyping which needs extremely high resolution and where price is no object, but there is still a strong market for deposition style printers because the material cost is much lower. Resolution can still be quite high with the deposition style printers, the MakerBot is an entry level printer and professional users with more money to spend can get much better ones.
If you actually read the announcement from Google and watch the short video you will see that this is not even available for the typical non-celebrity/-public figure users. Google is apparently working on making it available to all users, but nothing in the announcement suggests that this is more than a voluntary feature you can use if you want people adding you know that it's the real you and not somebody else. It seems like this would be a very useful feature indeed for public figure types.
There's no point in freaking out about this unless Google does make it mandatory. Even if it is made mandatory I'm not sure I'd freak out over it. I use my real name on Facebook and on Google Plus already, so my anonymity on these sites is not an issue. I prefer Google Plus over Facebook because (so far) I have much better control over my privacy, and this doesn't appear to be a privacy issue.
Slashdot Mirror
We're interested in anything geeky and technical (at least I am), but you can't squeeze blood from a turnip, or at least not much. So you can talk about products that have new features as long as the features are actually interesting and new. Or you can talk about the features from a technical standpoint, showing what the features really mean, what's important, and what's physically achievable, instead of just rattling off specs like a Best Buy salesman who doesn't understand the product or the specifications.
Taking the Plantronics video as an example, there isn't a whole lot of interesting stuff going on there because they're just making very run of the mill consumer/business products. You could try and squeeze out something good talking about the wireless interface design, or frequency response, noise floor, and distortion in the audio quality, or what makes one headset ergonomic and another uncomfortable, or whether bacteria really grow faster in your ears when you're wearing headphones, just to name a few ideas. But by going with Plantronics you're limiting your options, because their products are fairly boring.
If you want to do a video about computer interface devices you'll have an easier time if you pick something that's already geeky, maybe gaming mice. Then you can get a company that really cares about its products who will tell you about the ergonomics and how their latency and movement accuracy is better than another company's, and they'll have numbers to back it up, and maybe talk a bit about how they accomplished those things. Or talk to monitor manufacturers about new display technologies like OLEDs and 3D, just make sure not to get caught up in marketing-speak. Even better if you could get a monitor manufacturer to HONESTLY discuss monitor specifications like why the contrast ratios are generally BS, how accurate the colors are and how to color calibrate your monitor, and what to look for if you're buying a monitor for watching videos or gaming.
You could also delve into wireless standards, look at all of the different technologies that carriers are calling 4G and what the actual performance of each is and whether it really deserves to be called 4G. Keep an eye on new ultra high speed wireless technologies like Intel WiDi or anything else operating in the 57-64GHz ISM band.
Of course this is just a few of my thoughts about what kinds of information about products are interesting, not about whether it makes a good video. I'm generally not a fan of videos versus static content unless the videos are really well done, or unless you're taking advantage of videos to show something that can't easily be presented in a static page. A big part of that is that videos generally take longer to watch and have less information.
Most areas quite reasonably have building height restrictions so that you can't arbitrarily block neighbor's views or cast shade on their homes/offices by building much taller than an area's prevailing building height. It will not necessarily be trivial to get a building permit to install a tower on top of your roof. And although you can obviously get more power per unit footprint by packing 32 time more solar cells into the tower which is what the researchers did this does not scale up to larger footprints because you will have to space the units out wider so that the towers are not shaded by their neighbors.
The researchers admit in their pre-print (http://arxiv.org/abs/1112.3266) that a full cost analysis (which would determine the actual value of their work) is beyond their preliminary analysis, but that does not stop them from claiming "Our results show that 3D sunlight collection has the potential to serve as a paradigm shift in solar energy conversion toward the Terawatt scale." I'm used to researchers hyping up their work to get funding, but I rarely see such arrogance in a paper.
Their work has some value in exploring solar structure designs that can get the most power in a given installation form factor without using any solar tracking solutions. But even if they do cost analysis on installed cost per average generated kWh their work is clearly incremental, not paradigm shifting.
As far as I know all superconductors have a critical current density, above which point the magnetic field generated in the wire exerts enough force on the electrons that the wire is no longer a superconductor, which means at low voltage to sustain the large currents the wires would need to be much thicker. In-town distribution before transformer conversion to +/-120V is often at around 4kV, the superconducting wire would need 800 times the area to run at 5V. The massive current levels would also result in extreme problems designing fuses and switches for substations, power lines, and customer entry points. It's even harder if the current is DC instead of AC because there is no current zero crossing to help extinguish the arc. Distribution and transmission voltages could certainly be lowered, but there will be problems lowering it by over an order of magnitude which probably outweigh the small number of people who electrocute themselves.
While 9V can be fatal, 40V is a rule of thumb lower safety limit valid under most reasonable conditions. Actual fatal voltages can vary dramatically due to skin resistance varying over orders of magnitude and whether the current path goes close to your heart or not. To be in danger below 40V generally requires (as in your Darwin award) penetration of the skin, or contact over large areas with water.
The simple and necessary action (reviewing, confirming, and releasing the video) was done very shortly after we became aware of the issue -- several hours ago.
Why weren't you already aware of the issue when Rumblefish's claim was disputed the first time? Every time your company makes a fraudulent copyright claim there won't necessarily be a Slashdot story to catch your attention and call you on your mistakes.
Was there even a review process when this was first disputed? Was this a one-off mistake or is your review process inadequate? The bar of standards should be set high when you are claiming ownership over somebody else's content.
Then the GPS industry should buy the spectrum if it's necessary for proper operation of their devices.
You mean the US government? Because they are the ones who own, built, and operate the GPS satellite system and the associated spectrum. It is a critical resource for military, commercial, and personal use, and FCC spectrum regulations have long been in place to prevent interference to satellite bands which involve very low signal levels by the time the signals reach earth.
The "GPS industry" has always had the spectrum that they need, Lightsquared is the one butting in because their transmitters leak interference into the GPS L1 band.
(1) The FCC is not in any way saying that licensed users cannot transmit close to the GPS band. The band Lightsquared is using is intended for satellite-earth transmissions because they will be at similar power levels at ground to the GPS signal and thus will not pose an interference problem. Lightsquared tried to weasel an exception out of the FCC and failed. GPS is a critical system used by millions of people on a daily basis and it is clearly more important than a cellular network that is trying to operate in a band they shouldn't be in.
(2) Better filtering requires a combination of three things: (a) increased size, (b) increased cost, (c) lower quality passband signal (higher attenuation). By making intelligent allocations of spectrum with their oversight the FCC can ensure better utilization of finite bandwidth than if it was a free-for-all and everybody had to install huge expensive filters on their RF front-ends. The FCC decrees that transmitters operating close to the GPS band (and other satellite-earth bands) do so at sufficiently low power levels to avoid interference, which ensures that the millions of GPS receivers can be (a) smaller, (b) cheaper, and (c) higher performance. For very high performance GPS receivers this filtering is very difficult too, because the bandwidth of the GPS receiver is intentionally widened to get more signal. Are you seriously suggesting that the tens to hundreds of millions of GPS receivers in use today need to be replaced with (a) larger, (b) more expensive, (c) lower performance receivers just so that we can all cater to the whims of a startup company that tried to game the system and lost?
I'm not sure if I should bother replying to you as there is a reasonable chance you are astroturfing for Lightsquared, but in case you're not I hope you will consider these issues before spouting off more of these posts which assume Lightsquared is innocent in this (they are not).
In Western theological terms, that's like saying that Christ is an inspirational person with some really interesting teachings, but not the Son of God. That's about as blasphemous as you can get.
So Judaism is blasphemy?
You might be right that the place for this tech is a pre-treatment for an RO process, but it isn't mentioned in the article and the researchers appear to be looking for a gadget "where you put saltwater in one side and delicious drinking water comes out the other":
I'd be dubious about the efficiency of doing this electrochemical desalinization to remove so much of the salt, I would think that the resistance of the water is going to rise substantially as salt leaves so it seems like more and more electrical energy will be required per mole of salt ions as the concentration drops.
So by pre-treating water to remove much of the salt before sending it to RO the membranes will last longer before replacement? How much of the operating cost of an RO plant is determined by this? Would there be an impact on the RO process energy consumption?
Although that has been the default for most engineering PhD students, it is getting harder and harder to find funding as a grad student due to universities shrinking their TA budget and government agencies and companies shrinking their R&D budget. Masters students always have a hard time getting funding for grad school because few professors want to pay a student who will be leaving soon anyway and has little experience yet, and universities want to save their TA funding for the students who will be getting PhD's and thus making the university look good.
Since the original article is about R&D, I'm assuming we're talking about STEM (science, technology, engineering, math) PhD's, in which case you most certainly earn more once you have the degree. Of course somebody with a lesser degree and more experience might make a similar amount, but the same person with a higher degree will generally be paid more. And yes it disqualifies you from (or at least makes it harder to get) low-level jobs, because the company rightly assumes a PhD would be unhappy doing low-level work and would quit for a better job.
Most engineering PhD's go into industry either in the field of their PhD or into new fields. Becoming a university professor is actually a very challenging and competitive career path, since a university professor is expected to be both a leader in research and teaching. Of course there are still other academic jobs such as assistant/associate prof, lecturer, and there are non-PhD granting colleges which are easier academic jobs, but still most PhD's are happy to leave academia for the higher paid and less stressful industry jobs.
I thought the orangeish color was there because sodium vapor lamps are a cheap compact high-power bulb technology. White HID bulbs using rare earth metals to emit more colors are more expensive.
In order to make lego bricks which both hold together firmly and can be easily pried apart requires precision injection molding http://entertainment.howstuffworks.com/lego1.htm, http://en.wikipedia.org/wiki/Lego#Manufacture. 3D printers don't have the tolerance, material strength, nor finish quality required for producing strong tight-tolerance pieces like this. Printing is just a fundamentally different manufacturing process which is good for certain tasks but not this kind of task.
There are stereolithography machines which do additive manufacturing by curing a photosensitive polymer one layer at a time, and these can be quite precise. However they are slow and very expensive to run. They are useful for some specialized tasks like building structures which could not be machined in a single piece using traditional machining equipment due to internal structures. There is little choice of material though as you are limited only to liquids that are photo-curable and you only get to choose one material for a given solid piece. There's no manufacturing revolution here, it's a specialized piece of equipment which produces small quantities of parts at a high price. Useful for prototyping and specialized tasks, not mass production.
21 year old academics (even Stephen Hawking) are not professors, they are undergrads or grad students, and they do not get professor-level health insurance plans from the university. I'm a grad student on my university's health insurance policy, it's not bad at least for routine care although the co-pays are higher than when I was on my parent's plan. It costs me a little over $2,200/year, which is admittedly much less than tuition. Sidenote: thanks to "Obamacare" it is much easier for kids to stay on their parents health insurance plan to an older age (26 I think?), which is great if (A) your parent has a job with health insurance and (B) putting you on your parents plan doesn't cost more than you and your parent can afford.
Yep :(
T-Mobile has been offering discounted no-contract plans if you bring your own phone for at least two years now, which is when I first got one of these plans. The T-Mobile Value plan for individuals with 500 minutes, unlimited texts, and 2GB of data for $50/mo is essentially equivalent to my current plan which is no longer offered on the website. It is also pretty similar to the Monthly4G prepaid plans from T-Mobile.
Of course the next issue is that of compatibility. There are so many radio bands and communication standards to cover in the USA that when you buy your own phone you have to do a bit of extra research to make sure your phone is compatible with your intended network's high speed data options.
I wrote up a little section on why wearable organic transistors are not well suited for any real digital computation to add on to your post (longer physical propagation delays, extremely slow FETs, high resistance interconnect, uneven/changing surrounding dielectric environment), but then I read the paper and realized that it's just the poor journalism at ExtremeTech that was talking up that angle. The actual researchers don't mention high power digital circuits like ExtremeTech, in fact the only application I saw that the paper directly mentioned was chemical and biological sensors.
The actual computing horsepower for wearable computers with any real complexity will obviously need to be provided by conventional CMOS chips for years to come. They are tiny and can be integrated in clothing with little impact and easily ruggedized for washing machines, they use far less battery power, they are reliable, and can actually provide real computing power. The place for integrated organic semiconductors in wearable computing is for things like displays and sensors which don't need high speed transistors but need large areas, flexibility, or interesting chemical properties. There is undoubtedly going be a place for very simple circuits directly implemented in organic textile based transistors, but it's not going to power a GPS receiver or anything fancy like that.
This is a well-known consideration when using bodies of water for cooling, and I'd be surprised if the environmental impact review for this project failed to do the calculations and address this issue. It's part of the discussion here. Some power plants even need to decrease their output power when outdoor temperatures rise in order to comply with regulations on how much heat they can dump into their sources of cooling water.
It's actually not particularly difficult these days to create a compact and cheap boost converter, chips are available with everything included but the external inductor and coupling capacitors. Inductors can be large, but nowadays it's easy to find very compact SMT inductors. The efficiency may not be great due to higher resistance and core loss but it can be made quite cheaply and compactly.
Although the article claims to be talking about a silicon *transceiver* running at *300+GHz*, the graphics included in the article just have a planar horn antenna and a diode on an InP substrate all connected up to a SMA connector. A bit disappointing to be honest. No mention of whether they're using the diode as a detector or mixer (or both), but the pieces they are talking about appear to be a long ways away from an actual communication system.
One of the big problems faced in reality will be getting enough power to overcome the high losses at THz frequencies, particularly if they are eschewing LNA's and PA's at the front end and using the diodes for up-/down-conversion. Given the simplicity of the front-end it will require a lot more complexity and high-power in the back-end circuitry which they make no mention of solving. And if they are using some high-harmonic mixing with that diode then they're probably not going to meet regulatory emission requirements using just the antenna structure to filter out radiation of the spurious mixing products.
I've never suspected students of cheating during exams, but I do notice it when grading homeworks and two students who turn in their homework assignment one after another have identical wrong answers, or answers identical to the solutions manual which any determined student can usually get.
Most of the time I did not take action when I suspected it, due the lack of complete certainty, the hassle you describe, and the fact that many professors did not encourage taking it seriously since the test scores were weighted more heavily anyway.
I did take action a couple of times. One time I was certain that a pair of students had copied from the solutions manual (it was a handwritten manual easily available as PDF online, both students had incorrectly transcribed a smudged section in a nonsensical way that made perfect sense if you had the solutions manual in front of you), so I gave them both zeros on the full assignment with a note not to copy from the solutions manual. Didn't hear a peep from either one when they collected their homework. The other time was a take home final where two students had liberally used each others' work (shoddy work I might add). When I let the prof know he just asked me to send a warning email (way to take action Prof. ______!) and so I did that and cut the two students' points in half.
This is anecdotal, but I have worked in defense contracting companies and there I was an "exempt" employee, meaning that I wouldn't get paid overtime if I go over 8 hours in a day, or 40 in a week though I was paid straight time if I worked late. I would take my lunch whenever I felt like it as nobody was checking on when or if I did. As I would set my own schedule within reason based on current projects and deadlines, I would sometimes end up working very long or short hours as necessary.
Then again I was working in R&D, it wouldn't surprise me if there are more specific rules for skilled manual labor as they probably don't want a welder working 12 hour days or skipping meals until he's tired and makes an expensive or dangerous mistake. Sometimes things like this can also a result of specific union rules.
My guess for a situation like welding on a nuclear submarine is that management and the military want to dot the i's and cross the t's as precisely as they can in terms of following laws and procedures so that if something does get screwed up on the sub or an employee gets injured they don't want anybody to be able to point a finger at the labor practices of management.
DARPA does love crazy game changing ideas like this... but you'll have a tough time getting this one past a technical review since you appear to be unaware of some serious technical issues.
It really isn't. A cell phone tower is a just a tower with many directional antennas on it. Typically antennas are installed in a trio each one covering 120 degrees, to separate the three "cells" the tower covers. Each antenna has its gain focused on the ground level where the customers are located. The gain straight up will be terrible. Because of this direction you'll be raising the noise temperature of the antenna dramatically because its picking up thermal noise from the hot ground, which will hurt your sensitivity quite a bit.
Then there are issues like sidelobe mitigation (which you can't do since the towers are fixed), radio interference (these are cell phone towers after all), actually getting the phase between multiple towers synchronized (not as easy as you think), the cost will be far higher than your student's guess (you'll need your own RF hardware, the cell phone receivers won't cut it), and the tower operators and antenna operators aren't going to be nearly as accommodating as you assume.
I think you'll be fine :-)
You are correct, there is a definitive minimum energy required to split up a water molecule and get out hydrogen and oxygen. This energy is the same as the potential energy that would be released if you burned the two gases together in an exothermic reaction, getting the water back. Typically though electrolysis uses much more energy than that, because there is a certain "activation energy" threshold that you have to reach before the reaction can occur. Without a catalyst you have to put in extra energy to get over this barrier, and the extra energy left over at the end turns into heat. If splitting the water molecule is like pulling a weight a certain height up a hill (in terms of potential energy), the activation energy is an extra hump you have to pull the weight over, after which the weight is free to roll back down to the final height. See this illustrate here: activation energy plot.
So a catalyst does not let you get energy for free, but it lets you turn electrical energy into chemical energy of hydrogen and oxygen with less wasted energy.
You are jumping the gun quite a bit with your proclamation I think. Google+ is still a very new product, Google is doing fine as a company and will not dump this attempt because they got scared after less than 6 months of operation. Plenty of people, including myself, use it in addition to Facebook, and some people I know use it instead of Facebook. Maybe your social group doesn't use it, but that's their choice. It makes a lot of sense for Google to have a social media platform at their disposal as people spend so much time on social media sites, and they need eyeballs to sell ads. I have never been pissed off or suspicious about Google's intentions with Google+. So no, Google+ is not a failure and we won't be able to say it is for some time.
Side note: I don't understand why you think a Google+ failure would leak over into other services like Gmail. Gmail is still a very distinct service from Google+.
You are correct sir! The datacenters hosting the websites selling you products online are floating in the sky, not a building on a public road. Similarly, the warehouses from which these products are shipping and the offices housing the people who run and manage the company are floating in the sky. There are no trucks that ship the products to you on public roads because physicists have perfected teleportation, but are currently only licensing it to online retailers.
This appears to be an argument against all sales tax rather than merely against online sales taxes, by saying that everything can be paid for from property tax. One might argue that it would be a more regressive tax, because in a store (online or brick-and-mortar) selling luxury or high-end products the ratio of the value of the annual transactions to the value of the property would be much higher for luxury items. It would also make the progressive exceptions to sales tax on groceries that many (all?) states implement very complicated to lay out in the property tax code.
Yes, no crime or theft ever took place in a shipping warehouse, or on the roads that shipments travel on, but brick-and-mortar stores are wretched hives of scum and villainy (/sarcasm). Maybe there are different levels of crime, but at most that would suggest a sales tax discount for online sales, not elimination.
In 22 of the 50 states (according to Wikipedia), internet sales are already taxed as a "use tax" but many people do not report it on their state tax return, essentially committing tax fraud. Having online retailers collect the tax is simply a more effective way of collecting an existing tax, at least in those 22 states.
To put the government's argument quite simply: The states and counties had a source of tax revenue with which to provide government services. Parts of this revenue were lost due to online shopping that goes untaxed. The level of services that the taxpayers want from the government is mostly unaffected. The choice is then to collect more taxes in some other way, cut government services, or go into debt. It's so easy to say that government is wasteful and spending should be cut, but it's incredibly hard to run an organization the size of the government efficiently and the government does do a lot of useful things for us that wouldn't happen without taxes.
The video you link appears to be a DIY stereolithography machine. These machines are very nice and create 3D parts with extremely high resolution. I have seen the output from one of these machines at a company I have worked out, the resolution is better than 100um and the parts that it produced needed no additional machining (in fact they were producing parts that could not have been produced in a single piece by machine). However the machine itself cost over $100k, and the resin costs $100's per liter. It makes a lot of sense for high end prototyping which needs extremely high resolution and where price is no object, but there is still a strong market for deposition style printers because the material cost is much lower. Resolution can still be quite high with the deposition style printers, the MakerBot is an entry level printer and professional users with more money to spend can get much better ones.
If you actually read the announcement from Google and watch the short video you will see that this is not even available for the typical non-celebrity/-public figure users. Google is apparently working on making it available to all users, but nothing in the announcement suggests that this is more than a voluntary feature you can use if you want people adding you know that it's the real you and not somebody else. It seems like this would be a very useful feature indeed for public figure types.
There's no point in freaking out about this unless Google does make it mandatory. Even if it is made mandatory I'm not sure I'd freak out over it. I use my real name on Facebook and on Google Plus already, so my anonymity on these sites is not an issue. I prefer Google Plus over Facebook because (so far) I have much better control over my privacy, and this doesn't appear to be a privacy issue.