A little background (good question): To the best of our knowledge, there's no such thing as gravity "on" something; all gravity is *between* things. Think of it like magnetism (in fact, if you change the constants and swap charge and mass, the formulae for computing magnetic attraction and gravitational attraction are the same). When the Earth's gravity imparts momentum to an object (an apple you drop, say), the apple's gravity imparts the same momentum on the Earth. Of course, since momentum is mass times velocity, and the Earth masses ludicrously more than an apple, the delta-V of the Earth is basically imperceptible. Momentum is still conserved, though.
Now, as far as a space drive goes... we can't use gravity as a drive right now, because it always just pulls towards nearby massive objects (and because we can't control it in any way). We can accelerate using gravity - you've probably heard how some space probes would "slingshot" around massive planets to gain a lot of speed on a different vector - but in order to do that we first need an acceleration that we create ourselves, so that we don't just fall straight down the gravity well.
So yes, gravity imparts momentum (to both spacecraft and the planets they slingshot around) without *itself* involving a high-momentum exhaust... but only because the spacecraft already had a lot of momentum in the correct direction for the maneuver. Getting *that* momentum has, so far, always required an exhaust.
There are other options for generating thrust in space - light drives (the "exhaust" is just massless photons) and solar sails (where the high-momentum particles come from something else, like a star), for example - but neither are currently practical. Of course, even if the EmDrive happens to really work (which the experiments support but have definitely not yet proven) it isn't yet practical either. NASA has tested a *lot* of experimental drive types. However, at this time, all of the ones that have actually flown are reaction drives (throw something out the back of the ship, get an equal and opposite reaction forward). That may change at some point in the future, though.
Since there's already a pre-release version of IE12, probably not! They've increased the release rate a good bit the last few years; Win7 shipped with IE8. Still nowhere near as fast as Firefox and Chrome bump their "major" version numbers these days, of course, but that's no surprise.
Thank you. The hilarious thing is that this time, the zealots aren't even reading the report before "debunking" it. TFA (and, to be fair, lots of other sources) confused the recent NASA experiments on the Cannae Drive for experiments on the EmDrive. These are similar devices, but are invented by different people and their inventors claim different explanations for how they work. The actual inventor of the EmDrive (whose device was also tested, and produced more than twice as much thrust as the ~40 from the Cannae Drive as mentioned in TFA) is arguably vindicated by the result; having built something "different" but of basically the same design, it *also* produced thrust!
Oh, and that "null" device? That was the lack of a supposedly-required feature on the Cannae Drive, without which it supposedly is inoperative. The *actual* EmDrive has never required any such modification (radial slots on the chamber). Shawyer (inventor of the EmDrive) is probably also wrong about how it works and or even whether it does... but not for the reasons that all the idiots - most of whom *don't* even have lab coats - are claiming.
A good article refuting the claims of things like TFA (found by somebody else but worth reading): http://www.wired.co.uk/news/ar.... A more powerful test device is already in development and will be tried out at multiple labs on multiple apparatus. *THEN* we will see whether to change the textbooks...
Sadly, you're actually wrong even though you're right. Shawyer never said that the "null" device wouldn't produce thrust. That was the claim of a guy named Guido Fetta, who invented something he calls the Cannae Drive (http://en.wikipedia.org/wiki/EmDrive#Cannae_drive). Shawyer just said that the Cannae Drive is an inefficient EmDrive, with or without the slots which distinguished the "null" device from the "real" one.
Oh, and when NASA tested the actual EmDrive (which was months ago), it actually produced more than twice the thrust on just over half the power. Every result that TFA "reports" for the EmDrive is actually from the Cannae Drive test, not the EmDrive test at all! The author of that piece of dross needs to be hit with a clue-by-four...
Note that I'm not saying the EmDrive is "real". I'm definitely not saying Shawyer has a valid explanation for how it works either, even if it does. However, the experiments so far disproved nothing except Fetta's theory of the Cannae Drive; arguably, it actually provided *support* for Shawyer.
Bigger stupid one: the "null" device wasn't even supposed to be an EmDrive. It was supposed to be a Cannae Drive, which has a similar design but was invented by a completely different person and (supposedly) operates on different principles. The inventor of the Cannae Drive claimed that the difference between the null and actual test devices would mean there were different results. He was wrong, as shown experimentally.
The actual inventor of the EmDrive (whose device was also tested by NASA, months ago, and was produced twice the thrust on 60% as much power) says that the Cannae Drive is just an inefficient EmDrive in either null or "real" configuration. http://en.wikipedia.org/wiki/E...
Thank you. The Fucking "Article" in the summary gets it so wrong I want to find the moron who wrote it and force him to actually read the paper that he gets almost completely wrong.
Error 1) The Cannae Drive and the EmDrive are not the same thing, at least according to the inventor of the Cannae Drive. Every result that the article talks about for the EmDrive was actually from NASA testing the Cannae Drive.
Error 2) The difference between the test and "null" devices was that one of them had slots on it (believed to be required for the Cannae Drive) and the other did not. According to Fetta (the inventor of the Cannae Drive, not just another person who built an EmDrive to test out), these slots are required. According to Shawyer (the guy who actually invented the EmDrive), they are not required. Looks like the EmDrive guy was right: they weren't required. This is addressed in Q2 of your fine link.
Error 3) TFA never mentions this, but NASA Eagleworks *ALSO* tested Shawyer's version of the drive. It was over 3 times as efficient, producing about 91 microNewtons of thrust from 17 Watts of power (the Cannae Drive got 40uN from 27W). They didn't have a "null" device for that one, aside from a resistive dummy load... which produced no thrust when energized. Also, the tested drives produced no thrust when *not* energized.
I really wish people would stop parroting the false claims in TFA.
Oh for fuck's sake... Time to debunk this shit, again. TFA got it wrong as well, so I suppose I can't blame you people for getting it wrong too, but please try doing a little more research?
A little background: The EmDrive was invented by a guy named Shawyer. It was tested by NASA, among others, and found to produce about 91 microNewtons. (I'll address the 30-50 that TFA talks about too.) That's way less than the Chinese found, but NASA was also testing it at much lower power and say they are planning to test a higher-power version.
The article mentions "... and a third person, Guido Fetta, have built three separate versions of the EmDrive". This is wrong, at least according to Fetta. Fetta invented what he calls a "Cannae Drive" (http://en.wikipedia.org/wiki/EmDrive#Cannae_drive) which resembles an EmDrive but supposedly works on a different principle. In particular, Fetta believes that his drive requires radial slots in the chamber to operate. To test this, two versions of the Cannae Drive were (also, separately from the EmDrive test) tested by NASA: one with and one without the slots. Those tests both produced the same thrust (30-50 microN, about half what the EmDrive produced), which disproves Fetta's theory as to how the Cannae Drive is supposed to work.... and nothing else.
The null test device that everybody is so dismissedly claiming claiming disproves the EmDrive wasn't even supposed to be an EmDrive! Fetta, inventor of the Cannae Drive, was disproven. Shawyer, inventor of the EmDrive, was actually vindicated because according to his theory, the Cannae Drive (slots or no) is basically an inefficiently-shaped EmDrive.
I don't know why this is so hard for people to understand.
If you're actually DDOSing my network - as opposed to, say, just using a lot of it for its intended purpose of accessing data - I might press charges. Intent matters. Slashdot regularly causes events that *look* a lot like a DDOS, but that doesn't mean slashdotting a site is a criminal activity.
If I am not authorized to physically access your closet and I do so anyhow, press charges against me - for TRESSPASSING, you moronic lump of ostensibly-sapient matter. Not for "hacking".
The funny thing about your comment - which, despite having done everything recommended here and more* in college, I still can't help but read in the voice of a sour, grumpy old man - is that you don't need to know anything more than JavaScript to study algorithms. You don't even need that much, in fact; I'm not sure if my algorithms professor actually *knew* any programming languages; examples were written in pseudo-code and code could be turned in in any language that the TAs knew. A programming language (admittedly, JS is a poor choice here) can make it convenient to implement an algorithm, but you can describe them and analyze them without any such concrete thing.
* x86, MIPS, ARM, and ATMega16 assembly, both NT and Linux kernel-mode code, multiple classes on algorithms and data structures, databases, C (obviously) including bit-twiddling and explicit memory management in a multi-threaded networked application, and yes I also wrote (a large part of) a networked 3-D real-time videogame. Ironically, everything I know about web dev I actually learned outside of my classes. University of Washington Seattle, in case you're curious.
He didn't sign a thing, retard. There's nowhere on a website's TOS to sign, nor is there anywhere to dispute or modify a clause, nor is there any prevention against one party (specifically, the one whose agreement with the terms is not required) later modifying the terms. It's not a contract. It's not even a half-decent mockup of one.
Of course, even if it were a contract, civil contract violations are a matter for lawsuits not criminal charges. So he *DID NOT* break the law. A website's TOS is not law, should never be treated as law, and the potentially horrific consequences of allowing a website's TOS to be enforced by the criminal "justice" system should be obvious to anybody whose IQ exceeds that of a baboon.
So, where does "THE FREAKING AIR IN THE CHAMBER" go then, smart guy? What does it impart its momentum to? How does this produce a *net* thrust in one direction?
Actually, screw all that shit. Fine. This thing produces a thrust in one direction when placed in a sealed chamber containing air at 1 bar. Strap it to your spaceship or satellite - sealed air-containing surrounding chamber included - and go to town.
Why do people comment on physics when they have "NO FREAKING CLUE ABOUT BASIC DYNAMICS"? You just reveal yourself as an idiot.
Fact 3: You're talking about the Cannae Drive, not the EmDrive. Fact 4: They (NASA Eagleworks) *ALSO* tested the EmDrive, and found that it produced approximately 91 microNewtons of thrust. Fact 5: According to the inventor of the EmDrive (who is NOT the inventor of the Cannae Drive), the Cannae Drive (in either normal or "null" variant) is just an inefficient EmDrive.
Now, I'm not saying that the EmDrive guy (Shawyer) is right. But *YOU* are wrong. There is no conclusive evidence of a systematic error in NASA's experiment. Ockham's Razor time: which of the following is more likely correct? 1) The inventors of the EmDrive (Shawyer) and the Cannae Drive (Fetta) are both correct that their drives produce thrust, but Fetta is wrong that the radial grooves (which the null test was lacking) are required, and Shawyer is correct that his version is more efficient (though his understanding of why may still be wrong). 2) Both inventors are completely wrong, the Chinese experiment is wrong, and the fact that all of the test devices produce detectable thrust in the appropriate direction regardless of which way they are pointed is a "a systematic error in NASA's experiment".
Uh huh. Leaving aside the problems with everything you just said, what happens when you turn it over and get the same result? How about when you place it on its side and get the same result? Seriously, that's a pretty obvious null test. They thought of it.
Actually, if it's proportional to the photon pressure, that's still pretty damn interesting... because the drive is *sealed*. There's nowhere for the photons to escape to. Light pressure is still an "equal and opposite reaction" deal. If microwave generation at one end of the chamber propels the drive one way, then microwaves impacting on the other end of the chamber ought to produce an equal propulsion the other way. Net thrust should be zero.
THE NET THRUST IS NOT ZERO! You appear to have completely misunderstood the design of the drive (not the supposed mechanism of it, the plain-English design). There's nowhere for photons, or ions, or electrons, or air molecules, or anything else to go. Either A) point out where the exhaust of these things comes from B) give a reason why they measured thrust when there actually wasn't any C) stop calling things "IMPOSSIBLE" when they are, by multiple independently conducted experimental results, happening.
It wasn't that long ago that Newtonian mechanics were "among the best tested bits of physics". Relativity showed they were only an approximation of the truth, and that under previously-untested experimental conditions they were not accurate. I'm not saying that something similar is undoubtedly happening here, but I am saying that you're an idiot for claiming that it's impossible for "one of the best tested bits of physics" to be wrong under unusual situations.
Sure, but it can't produce *consistently asymmetric* ones. If convection was responsible, than the *net* torque should have been zero since the entire system was sealed. Or rather, if it can, then hey, just make sure the drive container is full of air at atmospheric pressure when you mount it on your spacecraft!
That's not (necessarily) an "unexplained fault in the test apparatus", you idiot (speaking both to the AC and to the people who modded em up). That is an unexplained experimental result. How the fuck did at least four people, at time of writing, manage to get that wrong?
There were *THREE* test devices. (Seriously people, the summary and linked TFA sucks but what the fuck do you expect from/. anyhow? Do some further reading.)
Device 1: EmDrive, designed by Roger J. Shawyer. This is the same drive tested by the Chinese, though NASA ran the experiment at 1/50th the power of the Chinese experiment. The thrust produced per energy put in was far less than the Chinese reported, but it was non-zero. NASA apparently plans to test with a more powerful version of the drive (closer to the Chinese experiment).
Device 2: Cannae Drive (test article, as designed by Guido P. Fetta). This drive produced less thrust than the EmDrive but did produce some. Fetta claims that the drive requires "radial slots engraved along the bottom rim of the resonant cavity interior" in order to produce thrust. Shawyer claims that the Cannae Drive is basically just an inefficient EmDrive.
Device 3: Null version of Cannae Drive (lacking the slots, which Fetta says should mean no thrust but which are irrelevant to the supposed mechanism of the EmDrive). This version produced the same amount of thrust as the "real" Cannae Drive test device.
Why do you say "a version of the instrument"? There were two (non-null) test devices: an EmDrive and a Cannae Drive. According to its inventor, the Cannae Drive requires radial slots in the chamber and won't work without them. The EmDrive doesn't need such slots. According to the inventor of the EmDrive, the Cannae Drive is basically an inefficient EmDrive and the slots are irrelevant. To test the Cannae Drive (NOT the EmDrive!), a null version without the slots was tested as well.
Experimental result: All three devices produced thrust. The EmDrive produced more than the Cannae drive, but the Cannae drive produced the *same amount* of thrust whether it had the slots or not. That means Guido P. Fetta (inventor of the Cannae Drive) is wrong. It does *NOT* mean that Roger J. Shawyer, who invented the EmDrive, is wrong - in fact, to a degree it supports his claim that the Cannae Drive is just an EmDrive - although his own math is called into question by the low output even of the tested EmDrive.
Seriously, stop talking as if the inventors of Cannae Drive and EmDrive are the same group of people and believe that they work the same way. Fetta was shown to be flat-out wrong when the Null drive produced thrust too. Shawyer was shown to possibly be at least partly right (not proven, but not disproven either) when all three devices produced at least some thrust, and his produced more.
Do we know how careful the Chinese experiments were, relative to the NASA ones? Serious question, because yes, the difference *is* curious... but it's not necessarily due to one result being inaccurate. The experiments were not identical. NASA used much lower input energy, and a non-identical apparatus.
The expressing of thrust in terms of input energy (linearly) is weird and questionable for all the reasons you state. If thrust/energy does indeed remain constant regardless of velocity, then yes, that would appear to be usable for free energy. What this means is one of three things: 1) It doesn't, and we misunderstand the mechanism involved (since the latter half of that statement is almost certainly true, the first could be as well); 2) It does, but this doesn't produce free energy because our understanding of the physics there is wrong (unlikely but possible, if there is a thrust then it's caused by something our previous models did not account for and they only appeared to be accurate because of approximations at near-zero levels of this activity); 3) Free energy is possible after all, and everything that says otherwise is itself not entirely accurate).
By the way, you seem to have forgotten (or misunderstood) that there are multiple drive candidates being tested here. The null device producing thrust anyway indicates that the supposed mechanism of the second drive (the Cannae drive, *NOT* the EmDrive) is wrong. However, according to the inventor of the EmDrive, the Cannae Drive (with or without the slotting distinguishing the experimental and null devices) is basically an inefficient EmDrive. If the Cannae Drive does, in fact, produce thrust for the same reason that the EmDrive does (this assumes, as the experiment supports, that both drives produce thrust) then the supposedly-null device doesn't (dis)prove anything at all and needs no further explanation. Note that this doesn't require that the theories behind the EmDrive be correct, merely that they be less incorrect than the ones behind the Cannae Drive.
Don't get me wrong, I'm as skeptical as the physics as you are... but at the end of the day, the experimental result is what matters. The experimental result appears to disagree with your theories. Therefore, your theories appear to be wrong, or at least incomplete. What you *should* be doing is proposing modifications of your theories and ways to test their correctness. Proposing explanations for the experimental results that are consistent with the current theories (and ways to account for the discrepancy in future experiments) would also be valid. Saying "Nope, the math doesn't check out so it can't happen and anybody who says otherwise is a crank" is just flat-out bad science. We have an experimental result. The result is closer to what the alternative theory predicts than what your theory predicts. The burden is on you to explain that, if you want to maintain the current theory.
Spoken like somebody who has no fucking clue what "improvements for their core users" MS put in Windows 8 (that's 8.0 RTM, build 9200, though they've made significant improvements since then too).
Multi-monitor support: Taskbar across multiple monitors, with the option of app icons appearing on the taskbar of the monitor their window is on. Per-monitor DPI settings. Wallpaper spanning.
Performance: Page-combining for substantial reductions in RAM usage. Ludicrously fast boot time (and that's *actual* boot, not the hibernate-based thing you can do instead of real shutdowns).
System management: Greatly-improved Task Manager (examples include the ability to suspend/resume processes and the ability to control startup tasks). Win+X menu (also available by right-clicking the Start button) with a ton of handy Admin tools now at just two clicks away.
Virtualization support: Client Hyper-V is built in (OK, higher editions only). Built-in support (in the UI) for mounting VHDs.
Security: High-entropy ASLR and other exploit mitigation features/improvements. The option of using the sandboxed Windows Store apps (though yeah, their interfaces usually suck). Built-in anti-virus software. BitLocker volume encryption more widely available than before.
Convenience: Settings and some files can be set to automatically sync between different machines using the same Microsoft (formerly Windows Live) account. Password reset for your MS account - possible online - also lets you get back into your computer if you forget the password. Built-in email, calendar, and IM apps (they kind of suck but hey, they exist. It pissed me off that Vista had a perfectly good calendar app and then Win7 removed it). Ability to search the Store for an app that opens an unrecognized exception (again, app is likely to suck but that's better than getting a.7Z file from your tech-literate grandson and having no idea how to go about getting a tool that can open it). Built-in ISO mounting.
Repair/recovery: A better backup system than any previous Windows built-in one I've seen (not a very high bar, but still good). Ability to "refresh" the system to like-new state but without losing your files. Ability to easily create images for later reset operations (user-friendly OS snapshots, basically).
Other: Awareness of non-unlimited-data connections, with ability to limit background usage and set warning thresholds.
Don't get me wrong, they made a lot of wrong steps too (the way they butchered Start search pisses me off, though at least that one was fixed in 8.1, and the way you now find the Shutdown/Restart/Log Off options is initially confusing to practically everybody). The new desktop window decorations and so on (and lack of ability to go back to the old ones) is also a very questionable decision. For a lot of people, 8.0 isn't worth upgrading to even if they know about the improvements (especially since a lot of those improvements only really matter in certain configurations, like multi-monitor). But it's just wrong to claim that the OS doesn't have "improvements for their core users". That's true whether you consider "core users" to be business workstations, tech-savvy home users, or computer-illiterate grandparents.
Um... no? Networking is handled natively by NT, and both the Win32 and POSIX subsystems call into it. The network interface was exactly your standard Berkeley sockets, without WinSock initialization or special headers or anything like that.
I'll grant you that the underlying implementation of networking in SUA is a little funky - the ports are owned by psxss.exe, the native application that implements the "POSIX Subsystem Server" (similar to csrss.exe, which is the Win32 subsystem server) - but from the user perspective it works fine. OpenSSH (including server), git, svn, wget and curl, python, ruby, perl, links and lynx, Apache... hell, I even *wrote* some networked software for the subsystem, 5k lines of C that needed a total of five #ifdefs, most of just one line each, for portability to Linux as well (the main one that stands out in my mind was getting the MAC address; the IOCTL interface in the subsystem was present but a bit limited).
Until Win8.1, it was actually possible to install a "native" POSIX environment on NT-family OSes (which for most people means XP and anything since then). It had better performance and was more Unix-y than Cygwin - key differences include support for things like SetUID/SetGID/Sticky bits and case-sensitive file system (required NTFS, and could occasionally confuse Win32 programs if there were two files whose name differed only in case, but it worked), though there were others (like not tacking.EXE on the end of every program name). It was called SUA (Subsystem for Unix Application), and was quite useful for those who needed to run Windows software but wanted a bash shell and compatibility with scripts and software written for *nix (it had a complete GCC-based build toolchain, though you could also use MSVC, and was source-compatible with most portable *nix code).
It's still available, including the "tools and utilities" download that gives you basic shells and the like, but when MS released Win8.1 - which doesn't allow the POSIX subsystem - they also stopped funding the forums and package repo, so even if you can find the package files they're all getting more and more outdated.
I get that you think you're being funny, but lest somebody actually think that's going on here:
It doesn't say they lose money per sale. I strongly suspect they make a profit on each sale, though the summary doesn't say (and I haven't read TFA yet). What the summary says is that they're losing money overall, due to things like R&D costs and expanding production. In other words, investment costs are greater than profit.
In case it isn't yet obvious to you, this is the *EXACT* scenario where it's possible to "make it up in volume". Even leaving aside economies of scale, if they sell more cars (at a small profit on each) their overall income will exceed their expenses and they will be, overall, profitable.
The west coast in general has good TMo coverage (all the cities including the little ones, every time I checked when driving the I-5 from Seattle to SF, and the local ski areas) but the only other place I've checked was in DC (where it was fine). However, I scarcely even consider that "travel". For *REAL* travel, TMo is by far the best carrier option. I spent a month in Europe earlier this year. Six countries, and I had service everywhere in every one of them including on the Swiss ski slopes. I sent/received well over a thousand texts and a number of MMS, streamed music all day (at 128Kbps, that adds up fast), did email and web browsing and so forth, and Skyped with friends and family. I also received several calls which I let go to voicemail, then checked the voicemails. All on my normal US T-Mobile SIM card.
Extra cost for all that stuff while abroad? $0.00.
It would have cost something to use voice calls over the cellular network, but with things like Skype or Google Voice (plus the free and unlimited - though not super-fast - data), that was never needed. T-Mo's "WiFi Calling" feature also lets you make or receive calls, while overseas, without any charge as long as you're on WiFi. I'm planning to visit Indonesia soon, and T-Mobile says I'll be covered there too. It's a *fantastic* carrier for people who travel.
Slashdot Mirror
A little background (good question): To the best of our knowledge, there's no such thing as gravity "on" something; all gravity is *between* things. Think of it like magnetism (in fact, if you change the constants and swap charge and mass, the formulae for computing magnetic attraction and gravitational attraction are the same). When the Earth's gravity imparts momentum to an object (an apple you drop, say), the apple's gravity imparts the same momentum on the Earth. Of course, since momentum is mass times velocity, and the Earth masses ludicrously more than an apple, the delta-V of the Earth is basically imperceptible. Momentum is still conserved, though.
Now, as far as a space drive goes... we can't use gravity as a drive right now, because it always just pulls towards nearby massive objects (and because we can't control it in any way). We can accelerate using gravity - you've probably heard how some space probes would "slingshot" around massive planets to gain a lot of speed on a different vector - but in order to do that we first need an acceleration that we create ourselves, so that we don't just fall straight down the gravity well.
So yes, gravity imparts momentum (to both spacecraft and the planets they slingshot around) without *itself* involving a high-momentum exhaust... but only because the spacecraft already had a lot of momentum in the correct direction for the maneuver. Getting *that* momentum has, so far, always required an exhaust.
There are other options for generating thrust in space - light drives (the "exhaust" is just massless photons) and solar sails (where the high-momentum particles come from something else, like a star), for example - but neither are currently practical. Of course, even if the EmDrive happens to really work (which the experiments support but have definitely not yet proven) it isn't yet practical either. NASA has tested a *lot* of experimental drive types. However, at this time, all of the ones that have actually flown are reaction drives (throw something out the back of the ship, get an equal and opposite reaction forward). That may change at some point in the future, though.
Since there's already a pre-release version of IE12, probably not! They've increased the release rate a good bit the last few years; Win7 shipped with IE8. Still nowhere near as fast as Firefox and Chrome bump their "major" version numbers these days, of course, but that's no surprise.
Thank you. The hilarious thing is that this time, the zealots aren't even reading the report before "debunking" it. TFA (and, to be fair, lots of other sources) confused the recent NASA experiments on the Cannae Drive for experiments on the EmDrive. These are similar devices, but are invented by different people and their inventors claim different explanations for how they work. The actual inventor of the EmDrive (whose device was also tested, and produced more than twice as much thrust as the ~40 from the Cannae Drive as mentioned in TFA) is arguably vindicated by the result; having built something "different" but of basically the same design, it *also* produced thrust!
Oh, and that "null" device? That was the lack of a supposedly-required feature on the Cannae Drive, without which it supposedly is inoperative. The *actual* EmDrive has never required any such modification (radial slots on the chamber). Shawyer (inventor of the EmDrive) is probably also wrong about how it works and or even whether it does... but not for the reasons that all the idiots - most of whom *don't* even have lab coats - are claiming.
A good article refuting the claims of things like TFA (found by somebody else but worth reading): http://www.wired.co.uk/news/ar.... A more powerful test device is already in development and will be tried out at multiple labs on multiple apparatus. *THEN* we will see whether to change the textbooks...
Sadly, you're actually wrong even though you're right. Shawyer never said that the "null" device wouldn't produce thrust. That was the claim of a guy named Guido Fetta, who invented something he calls the Cannae Drive (http://en.wikipedia.org/wiki/EmDrive#Cannae_drive). Shawyer just said that the Cannae Drive is an inefficient EmDrive, with or without the slots which distinguished the "null" device from the "real" one.
Oh, and when NASA tested the actual EmDrive (which was months ago), it actually produced more than twice the thrust on just over half the power. Every result that TFA "reports" for the EmDrive is actually from the Cannae Drive test, not the EmDrive test at all! The author of that piece of dross needs to be hit with a clue-by-four...
Note that I'm not saying the EmDrive is "real". I'm definitely not saying Shawyer has a valid explanation for how it works either, even if it does. However, the experiments so far disproved nothing except Fetta's theory of the Cannae Drive; arguably, it actually provided *support* for Shawyer.
Bigger stupid one: the "null" device wasn't even supposed to be an EmDrive. It was supposed to be a Cannae Drive, which has a similar design but was invented by a completely different person and (supposedly) operates on different principles. The inventor of the Cannae Drive claimed that the difference between the null and actual test devices would mean there were different results. He was wrong, as shown experimentally.
The actual inventor of the EmDrive (whose device was also tested by NASA, months ago, and was produced twice the thrust on 60% as much power) says that the Cannae Drive is just an inefficient EmDrive in either null or "real" configuration. http://en.wikipedia.org/wiki/E...
Thank you. The Fucking "Article" in the summary gets it so wrong I want to find the moron who wrote it and force him to actually read the paper that he gets almost completely wrong.
Error 1) The Cannae Drive and the EmDrive are not the same thing, at least according to the inventor of the Cannae Drive. Every result that the article talks about for the EmDrive was actually from NASA testing the Cannae Drive.
Error 2) The difference between the test and "null" devices was that one of them had slots on it (believed to be required for the Cannae Drive) and the other did not. According to Fetta (the inventor of the Cannae Drive, not just another person who built an EmDrive to test out), these slots are required. According to Shawyer (the guy who actually invented the EmDrive), they are not required. Looks like the EmDrive guy was right: they weren't required. This is addressed in Q2 of your fine link.
Error 3) TFA never mentions this, but NASA Eagleworks *ALSO* tested Shawyer's version of the drive. It was over 3 times as efficient, producing about 91 microNewtons of thrust from 17 Watts of power (the Cannae Drive got 40uN from 27W). They didn't have a "null" device for that one, aside from a resistive dummy load... which produced no thrust when energized. Also, the tested drives produced no thrust when *not* energized.
I really wish people would stop parroting the false claims in TFA.
Oh for fuck's sake... Time to debunk this shit, again.
TFA got it wrong as well, so I suppose I can't blame you people for getting it wrong too, but please try doing a little more research?
A little background: The EmDrive was invented by a guy named Shawyer. It was tested by NASA, among others, and found to produce about 91 microNewtons. (I'll address the 30-50 that TFA talks about too.) That's way less than the Chinese found, but NASA was also testing it at much lower power and say they are planning to test a higher-power version.
The article mentions "... and a third person, Guido Fetta, have built three separate versions of the EmDrive". This is wrong, at least according to Fetta. Fetta invented what he calls a "Cannae Drive" (http://en.wikipedia.org/wiki/EmDrive#Cannae_drive) which resembles an EmDrive but supposedly works on a different principle. In particular, Fetta believes that his drive requires radial slots in the chamber to operate. To test this, two versions of the Cannae Drive were (also, separately from the EmDrive test) tested by NASA: one with and one without the slots. Those tests both produced the same thrust (30-50 microN, about half what the EmDrive produced), which disproves Fetta's theory as to how the Cannae Drive is supposed to work.... and nothing else.
The null test device that everybody is so dismissedly claiming claiming disproves the EmDrive wasn't even supposed to be an EmDrive! Fetta, inventor of the Cannae Drive, was disproven. Shawyer, inventor of the EmDrive, was actually vindicated because according to his theory, the Cannae Drive (slots or no) is basically an inefficiently-shaped EmDrive.
I don't know why this is so hard for people to understand.
If you're actually DDOSing my network - as opposed to, say, just using a lot of it for its intended purpose of accessing data - I might press charges. Intent matters. Slashdot regularly causes events that *look* a lot like a DDOS, but that doesn't mean slashdotting a site is a criminal activity.
If I am not authorized to physically access your closet and I do so anyhow, press charges against me - for TRESSPASSING, you moronic lump of ostensibly-sapient matter. Not for "hacking".
See the last line of my previous comment.
*JAVA* lacks destructors, but that's not a universal problem of GC languages.
The funny thing about your comment - which, despite having done everything recommended here and more* in college, I still can't help but read in the voice of a sour, grumpy old man - is that you don't need to know anything more than JavaScript to study algorithms. You don't even need that much, in fact; I'm not sure if my algorithms professor actually *knew* any programming languages; examples were written in pseudo-code and code could be turned in in any language that the TAs knew. A programming language (admittedly, JS is a poor choice here) can make it convenient to implement an algorithm, but you can describe them and analyze them without any such concrete thing.
* x86, MIPS, ARM, and ATMega16 assembly, both NT and Linux kernel-mode code, multiple classes on algorithms and data structures, databases, C (obviously) including bit-twiddling and explicit memory management in a multi-threaded networked application, and yes I also wrote (a large part of) a networked 3-D real-time videogame. Ironically, everything I know about web dev I actually learned outside of my classes. University of Washington Seattle, in case you're curious.
He didn't sign a thing, retard. There's nowhere on a website's TOS to sign, nor is there anywhere to dispute or modify a clause, nor is there any prevention against one party (specifically, the one whose agreement with the terms is not required) later modifying the terms. It's not a contract. It's not even a half-decent mockup of one.
Of course, even if it were a contract, civil contract violations are a matter for lawsuits not criminal charges. So he *DID NOT* break the law. A website's TOS is not law, should never be treated as law, and the potentially horrific consequences of allowing a website's TOS to be enforced by the criminal "justice" system should be obvious to anybody whose IQ exceeds that of a baboon.
Damn, the stupid is out in force today...
You can't steal what you already have a right to, genius. He had a legitimate right to access that data.
Now, if you want to charge him with trespassing, that is another matter. That's not what they were charging him with.
Oh, and you're an idiot. Thought you should know.
Uh huh. That is a possibility.
So, where does "THE FREAKING AIR IN THE CHAMBER" go then, smart guy? What does it impart its momentum to? How does this produce a *net* thrust in one direction?
Actually, screw all that shit. Fine. This thing produces a thrust in one direction when placed in a sealed chamber containing air at 1 bar. Strap it to your spaceship or satellite - sealed air-containing surrounding chamber included - and go to town.
Why do people comment on physics when they have "NO FREAKING CLUE ABOUT BASIC DYNAMICS"? You just reveal yourself as an idiot.
Fact 3: You're talking about the Cannae Drive, not the EmDrive.
Fact 4: They (NASA Eagleworks) *ALSO* tested the EmDrive, and found that it produced approximately 91 microNewtons of thrust.
Fact 5: According to the inventor of the EmDrive (who is NOT the inventor of the Cannae Drive), the Cannae Drive (in either normal or "null" variant) is just an inefficient EmDrive.
Now, I'm not saying that the EmDrive guy (Shawyer) is right. But *YOU* are wrong. There is no conclusive evidence of a systematic error in NASA's experiment.
Ockham's Razor time: which of the following is more likely correct?
1) The inventors of the EmDrive (Shawyer) and the Cannae Drive (Fetta) are both correct that their drives produce thrust, but Fetta is wrong that the radial grooves (which the null test was lacking) are required, and Shawyer is correct that his version is more efficient (though his understanding of why may still be wrong).
2) Both inventors are completely wrong, the Chinese experiment is wrong, and the fact that all of the test devices produce detectable thrust in the appropriate direction regardless of which way they are pointed is a "a systematic error in NASA's experiment".
Option 2 doesn't sound "obvious" at all.
Uh huh. Leaving aside the problems with everything you just said, what happens when you turn it over and get the same result? How about when you place it on its side and get the same result? Seriously, that's a pretty obvious null test. They thought of it.
Actually, if it's proportional to the photon pressure, that's still pretty damn interesting... because the drive is *sealed*. There's nowhere for the photons to escape to. Light pressure is still an "equal and opposite reaction" deal. If microwave generation at one end of the chamber propels the drive one way, then microwaves impacting on the other end of the chamber ought to produce an equal propulsion the other way. Net thrust should be zero.
THE NET THRUST IS NOT ZERO! You appear to have completely misunderstood the design of the drive (not the supposed mechanism of it, the plain-English design). There's nowhere for photons, or ions, or electrons, or air molecules, or anything else to go. Either
A) point out where the exhaust of these things comes from
B) give a reason why they measured thrust when there actually wasn't any
C) stop calling things "IMPOSSIBLE" when they are, by multiple independently conducted experimental results, happening.
It wasn't that long ago that Newtonian mechanics were "among the best tested bits of physics". Relativity showed they were only an approximation of the truth, and that under previously-untested experimental conditions they were not accurate. I'm not saying that something similar is undoubtedly happening here, but I am saying that you're an idiot for claiming that it's impossible for "one of the best tested bits of physics" to be wrong under unusual situations.
Sure, but it can't produce *consistently asymmetric* ones. If convection was responsible, than the *net* torque should have been zero since the entire system was sealed. Or rather, if it can, then hey, just make sure the drive container is full of air at atmospheric pressure when you mount it on your spacecraft!
That's not (necessarily) an "unexplained fault in the test apparatus", you idiot (speaking both to the AC and to the people who modded em up). That is an unexplained experimental result. How the fuck did at least four people, at time of writing, manage to get that wrong?
There were *THREE* test devices. (Seriously people, the summary and linked TFA sucks but what the fuck do you expect from /. anyhow? Do some further reading.)
Device 1: EmDrive, designed by Roger J. Shawyer. This is the same drive tested by the Chinese, though NASA ran the experiment at 1/50th the power of the Chinese experiment. The thrust produced per energy put in was far less than the Chinese reported, but it was non-zero. NASA apparently plans to test with a more powerful version of the drive (closer to the Chinese experiment).
Device 2: Cannae Drive (test article, as designed by Guido P. Fetta). This drive produced less thrust than the EmDrive but did produce some. Fetta claims that the drive requires "radial slots engraved along the bottom rim of the resonant cavity interior" in order to produce thrust. Shawyer claims that the Cannae Drive is basically just an inefficient EmDrive.
Device 3: Null version of Cannae Drive (lacking the slots, which Fetta says should mean no thrust but which are irrelevant to the supposed mechanism of the EmDrive). This version produced the same amount of thrust as the "real" Cannae Drive test device.
Why do you say "a version of the instrument"? There were two (non-null) test devices: an EmDrive and a Cannae Drive. According to its inventor, the Cannae Drive requires radial slots in the chamber and won't work without them. The EmDrive doesn't need such slots. According to the inventor of the EmDrive, the Cannae Drive is basically an inefficient EmDrive and the slots are irrelevant. To test the Cannae Drive (NOT the EmDrive!), a null version without the slots was tested as well.
Experimental result: All three devices produced thrust. The EmDrive produced more than the Cannae drive, but the Cannae drive produced the *same amount* of thrust whether it had the slots or not. That means Guido P. Fetta (inventor of the Cannae Drive) is wrong. It does *NOT* mean that Roger J. Shawyer, who invented the EmDrive, is wrong - in fact, to a degree it supports his claim that the Cannae Drive is just an EmDrive - although his own math is called into question by the low output even of the tested EmDrive.
Seriously, stop talking as if the inventors of Cannae Drive and EmDrive are the same group of people and believe that they work the same way. Fetta was shown to be flat-out wrong when the Null drive produced thrust too. Shawyer was shown to possibly be at least partly right (not proven, but not disproven either) when all three devices produced at least some thrust, and his produced more.
Do we know how careful the Chinese experiments were, relative to the NASA ones? Serious question, because yes, the difference *is* curious... but it's not necessarily due to one result being inaccurate. The experiments were not identical. NASA used much lower input energy, and a non-identical apparatus.
The expressing of thrust in terms of input energy (linearly) is weird and questionable for all the reasons you state. If thrust/energy does indeed remain constant regardless of velocity, then yes, that would appear to be usable for free energy. What this means is one of three things: 1) It doesn't, and we misunderstand the mechanism involved (since the latter half of that statement is almost certainly true, the first could be as well); 2) It does, but this doesn't produce free energy because our understanding of the physics there is wrong (unlikely but possible, if there is a thrust then it's caused by something our previous models did not account for and they only appeared to be accurate because of approximations at near-zero levels of this activity); 3) Free energy is possible after all, and everything that says otherwise is itself not entirely accurate).
By the way, you seem to have forgotten (or misunderstood) that there are multiple drive candidates being tested here. The null device producing thrust anyway indicates that the supposed mechanism of the second drive (the Cannae drive, *NOT* the EmDrive) is wrong. However, according to the inventor of the EmDrive, the Cannae Drive (with or without the slotting distinguishing the experimental and null devices) is basically an inefficient EmDrive. If the Cannae Drive does, in fact, produce thrust for the same reason that the EmDrive does (this assumes, as the experiment supports, that both drives produce thrust) then the supposedly-null device doesn't (dis)prove anything at all and needs no further explanation. Note that this doesn't require that the theories behind the EmDrive be correct, merely that they be less incorrect than the ones behind the Cannae Drive.
Don't get me wrong, I'm as skeptical as the physics as you are... but at the end of the day, the experimental result is what matters. The experimental result appears to disagree with your theories. Therefore, your theories appear to be wrong, or at least incomplete. What you *should* be doing is proposing modifications of your theories and ways to test their correctness. Proposing explanations for the experimental results that are consistent with the current theories (and ways to account for the discrepancy in future experiments) would also be valid. Saying "Nope, the math doesn't check out so it can't happen and anybody who says otherwise is a crank" is just flat-out bad science. We have an experimental result. The result is closer to what the alternative theory predicts than what your theory predicts. The burden is on you to explain that, if you want to maintain the current theory.
Spoken like somebody who has no fucking clue what "improvements for their core users" MS put in Windows 8 (that's 8.0 RTM, build 9200, though they've made significant improvements since then too).
Multi-monitor support: Taskbar across multiple monitors, with the option of app icons appearing on the taskbar of the monitor their window is on. Per-monitor DPI settings. Wallpaper spanning.
Performance: Page-combining for substantial reductions in RAM usage. Ludicrously fast boot time (and that's *actual* boot, not the hibernate-based thing you can do instead of real shutdowns).
System management: Greatly-improved Task Manager (examples include the ability to suspend/resume processes and the ability to control startup tasks). Win+X menu (also available by right-clicking the Start button) with a ton of handy Admin tools now at just two clicks away.
Virtualization support: Client Hyper-V is built in (OK, higher editions only). Built-in support (in the UI) for mounting VHDs.
Security: High-entropy ASLR and other exploit mitigation features/improvements. The option of using the sandboxed Windows Store apps (though yeah, their interfaces usually suck). Built-in anti-virus software. BitLocker volume encryption more widely available than before.
Convenience: Settings and some files can be set to automatically sync between different machines using the same Microsoft (formerly Windows Live) account. Password reset for your MS account - possible online - also lets you get back into your computer if you forget the password. Built-in email, calendar, and IM apps (they kind of suck but hey, they exist. It pissed me off that Vista had a perfectly good calendar app and then Win7 removed it). Ability to search the Store for an app that opens an unrecognized exception (again, app is likely to suck but that's better than getting a .7Z file from your tech-literate grandson and having no idea how to go about getting a tool that can open it). Built-in ISO mounting.
Repair/recovery: A better backup system than any previous Windows built-in one I've seen (not a very high bar, but still good). Ability to "refresh" the system to like-new state but without losing your files. Ability to easily create images for later reset operations (user-friendly OS snapshots, basically).
Other: Awareness of non-unlimited-data connections, with ability to limit background usage and set warning thresholds.
Don't get me wrong, they made a lot of wrong steps too (the way they butchered Start search pisses me off, though at least that one was fixed in 8.1, and the way you now find the Shutdown/Restart/Log Off options is initially confusing to practically everybody). The new desktop window decorations and so on (and lack of ability to go back to the old ones) is also a very questionable decision. For a lot of people, 8.0 isn't worth upgrading to even if they know about the improvements (especially since a lot of those improvements only really matter in certain configurations, like multi-monitor). But it's just wrong to claim that the OS doesn't have "improvements for their core users". That's true whether you consider "core users" to be business workstations, tech-savvy home users, or computer-illiterate grandparents.
Um... no? Networking is handled natively by NT, and both the Win32 and POSIX subsystems call into it. The network interface was exactly your standard Berkeley sockets, without WinSock initialization or special headers or anything like that.
I'll grant you that the underlying implementation of networking in SUA is a little funky - the ports are owned by psxss.exe, the native application that implements the "POSIX Subsystem Server" (similar to csrss.exe, which is the Win32 subsystem server) - but from the user perspective it works fine. OpenSSH (including server), git, svn, wget and curl, python, ruby, perl, links and lynx, Apache... hell, I even *wrote* some networked software for the subsystem, 5k lines of C that needed a total of five #ifdefs, most of just one line each, for portability to Linux as well (the main one that stands out in my mind was getting the MAC address; the IOCTL interface in the subsystem was present but a bit limited).
Until Win8.1, it was actually possible to install a "native" POSIX environment on NT-family OSes (which for most people means XP and anything since then). It had better performance and was more Unix-y than Cygwin - key differences include support for things like SetUID/SetGID/Sticky bits and case-sensitive file system (required NTFS, and could occasionally confuse Win32 programs if there were two files whose name differed only in case, but it worked), though there were others (like not tacking .EXE on the end of every program name). It was called SUA (Subsystem for Unix Application), and was quite useful for those who needed to run Windows software but wanted a bash shell and compatibility with scripts and software written for *nix (it had a complete GCC-based build toolchain, though you could also use MSVC, and was source-compatible with most portable *nix code).
It's still available, including the "tools and utilities" download that gives you basic shells and the like, but when MS released Win8.1 - which doesn't allow the POSIX subsystem - they also stopped funding the forums and package repo, so even if you can find the package files they're all getting more and more outdated.
I get that you think you're being funny, but lest somebody actually think that's going on here:
It doesn't say they lose money per sale. I strongly suspect they make a profit on each sale, though the summary doesn't say (and I haven't read TFA yet). What the summary says is that they're losing money overall, due to things like R&D costs and expanding production. In other words, investment costs are greater than profit.
In case it isn't yet obvious to you, this is the *EXACT* scenario where it's possible to "make it up in volume". Even leaving aside economies of scale, if they sell more cars (at a small profit on each) their overall income will exceed their expenses and they will be, overall, profitable.
The west coast in general has good TMo coverage (all the cities including the little ones, every time I checked when driving the I-5 from Seattle to SF, and the local ski areas) but the only other place I've checked was in DC (where it was fine). However, I scarcely even consider that "travel". For *REAL* travel, TMo is by far the best carrier option. I spent a month in Europe earlier this year. Six countries, and I had service everywhere in every one of them including on the Swiss ski slopes. I sent/received well over a thousand texts and a number of MMS, streamed music all day (at 128Kbps, that adds up fast), did email and web browsing and so forth, and Skyped with friends and family. I also received several calls which I let go to voicemail, then checked the voicemails. All on my normal US T-Mobile SIM card.
Extra cost for all that stuff while abroad? $0.00.
It would have cost something to use voice calls over the cellular network, but with things like Skype or Google Voice (plus the free and unlimited - though not super-fast - data), that was never needed. T-Mo's "WiFi Calling" feature also lets you make or receive calls, while overseas, without any charge as long as you're on WiFi. I'm planning to visit Indonesia soon, and T-Mobile says I'll be covered there too. It's a *fantastic* carrier for people who travel.