What you've really done is summarize the thoughts of Kip Thorne and Stephen Hawking
Aw, you didn't mention Larry Niven or Robert Forward!
I never claimed to have invented all or even most of the concepts there, and I thought I did pretty well to give credit to those who did. I do think the section on "Practical Consequences" is relatively novel, though. If you're trying to obliquely quote Samuel Johnson at me, well, everyone has their own taste.
The document you linked to... avoids the causality issue by "inventing" backward time travel that is creating alternate (new) reality.
Um, it very specifically says that's one alternative, not the only possibility. Of course, this is Slashdot - who bothers to RTFA? (Oh, and it doesn't claim to have 'invented' it, either.)
What if causality is a local condition and not a global one? Perhaps our intuitive understanding of causality only applies to regions without closed timelike curves, just like our intuitive notions of physics only apply to macroscopic objects moving slowly relative to light. Like a fish that had always lived in a smooth-flowing stream, and never encountered turbulent flow.
Boy, that went right over your head. Since elaboration is clearly necessary, I will spell it out: No, you didn't say that. But what you did say was in the same class as the statements I listed.
Causality prevents time travel and only an idiot would not understand it.
What if the Everett Interpretation of quantum mechanics is correct, and time-travel simply allows access to (or creation of) alternate worlds? In which case, there's no 'paradox', because in the case you propose (seeing a signal and then not sending it) you are in an alternate universe already and your action will, at most, simply prevent another alternate universe from being created.
But causality itself is rather more complicated anyway if you assume time travel is possible at all. We normally see effects coming after causes, but the very definition of time travel is effects coming before causes. And we have reason to believe it may well be possible. In a region where space is heavily twisted around (e.g. around a spinning black hole, and we have observations that strongly indicate (a) the existence of black holes, and (b) that they spin) the very straightforward calculations of GR show that closed timelike curves (time travel, basically) arise naturally.
We can imagine that our universe consists of three-dimensional moments arranged in a four-dimensional sequence. Even if we walk in a circle, we haven't returned to the same point - it's the same point in the three space dimensions we normally use, but it's displaced in the fourth, time dimension.
Note that this is exactly the model used by General Relativity. The universe, which we normally think of as being made of "space" and "time", is actually a single something called "spacetime". In Einstein's view, the world really is a static four-dimensional 'sculpture', and time really is, in a real sense, another measure of distance. Time normally proceeds at the speed of light - one second ago is one light-second (186,000 miles; 300,000 kilometers) away. As Einstein himself said, "Past, present, and future are illusions, if stubborn ones."
So it may be that if you receive a message from the future, you can't prevent it from being sent - from your perspective, anyway. If you receive the message, you obviously know it'll be sent - but you don't know that it was you that sent it, for example. Maybe you don't turn on the machine... but someone else does, or turns on a different machine somewhere else, etc. In such a model (totally consistent with GR, I'll again note) the future is exactly like the past - some things can be known about it, but some things you don't know.
This is a simple proof of causality that cannot be "circumvented" or "defeated". Nothing can "travel back in time". Period.
Yeah! And time can't slow down when you go close to the speed of light! And things can't act like both a particle and a wave! And particles can't tunnel through barriers they don't have the energy to escape!
For that matter, I'm not at all sure about these magical "fields" that act at a distance. And this whole "germ theory" of disease makes no sense - clearly it's just miasmas!
(Hint: you have not come up with a brand new objection to time travel, or even one that hasn't been answered before.)
Another example of a temporal paradox: Say someone in the year 2050 reads Einstein's works, and somehow builds a time machine based on them. He then travels back in time to 1900, meets Einstein, and ends up inspiring him to create his works. Who came up with the original idea for relativity? It's a paradox.
No, that's not a paradox. A "paradox" is a self-inconsistent set of circumstances - like killing your grandfather before you were born. What you're describing is something different; it is internally consistent, but depends on effects preceeding causes. (I like Andrew Plotkin's term for them - "perpendoxes", because they are orthogonal to paradoxes.)
Of course, that's the definition of time travel - if you don't have "effects preceeding causes" you don't have time travel at all.
It does seem weird that information could be created "out of nothing", but we didn't evolve around time travel. We didn't evolve around relativistic speeds and that seems unlikely and counterintuitive, too. We are used to thinking of things in a linear, cause-and-effect order, but you'd pretty much have to expect unusual things in a situation where that didn't apply.
Note that if you have time travel at all - if you can actually "travel to the past" (or make a photon do it) - then the past must actually exist somewhere.
As a matter of fact, in relativity it does - one second ago is physically one light-second away. But that would also mean that the future already exists - since every moment is past to some moments and future to others.
I don't think it's possible though, otherwise we would probably be getting messages from the future, wouldn't we?
That's like saying in 1870 that radio waves are impossible because nobody's received any. There weren't any receivers then. Or like saying neutrinos didn't exist before there were detectors for them.
It's quite possible that the as soon as we have something that can receive such messages it'll be flooded with spam from the future.
Hmm, my personal uneducated guess is that if you were using music tracks on the CD, rather than playing the music using the cd drive (straight to the soundcard via the tiny little cable) it's ripping the music in realtime and playing that.
Nah, when it plays the music via CD it's just using the SDL calls to start the CD playing analog, not via the digital interface. And in the one case, I don't even have the CD in at all and the framerate's still slow. But if I have the game load up an Ogg version of the song and play it in the background, something that should take more CPU, the framerate goes up. It's really weird. I'm not even sure how to debug it.
So, no CD - slow. CD playing - slow. Ogg music - fast. WTF?
I'm currently working on icculus' port of the older game "Aliens versus Predator". I noticed that the darn thing would run fine, ~30fps, on a PIII-700MHz with i810 graphics. But it ran like a dog,
On what I thought was an unrelated note, I added the ability to play the game music from Ogg files instead of off CD. For some weird reason, when the game is playing the music from files, the framerate is at least 50fps. If it can't find the files, the framerate drops again. Totally bizarre, but totally repeatable.
My current theory is that OpenAL's AL_EXT_VORBIS extension uses a hidden thread and some interaction there lets the game proceed. But that's just a guess. Anyone ever run into something like that?
Aliens versus Predator
on
Game Breakers
·
· Score: 1
The original release had a few unobtrusive FMVs (at the very beginning and very end of each species' campaign), and a whole lot of in-game FMVs that actually made some sense - they were videophones in the game and sometimes told you important information, sometimes were just for atmosphere. The in-game ones were done with actual actors.
In the "Gold" edition the programmers got to indulge their vanity and re-record the in-game FMVs themselves. An excellent example of why you should hire actors to do acting. The same lines, same framing, same lighting... but the "Gold edition" FMVs sucked compared to the originals.
(Fox/Rebellion released the source code and icculus ported it to Linux. (The cvs link there doesn't work, you need to use Subversion to get it.) It didn't link for me on Ubuntu, so I patched it. Unfortunately, the videos are in a proprietary codec (Bink/Smacker) and now I'm working on restoring them to the game. Looks like recent libavcodecs support that format...:-> )
I'd love something like this for my mom or little kids.
That's actually the primary use I've figured for it, as an introductory/educational tool. As people gain experience, they'll tend to use 2D or even 1D (command line:-> ) interfaces, but as a simple, relatively intuitive interface it has its advantages. People have hardware in their brains for quickly judging the shape, size, color, and material of an object, and for navigating by landmarks and such.
Note, too, that you could have a "home room" with doors leading off to commonly-used directories and an area with symlinks to the most-recently-used files, etc.
(And yeah, it'll need a lot of tuning to be aesthetically coherent. But I don't think it's quite so insurmountable as you say.:-> In any case, it might at least be an educational failure.)
Yeah. 3D is great for games and visualisation. Why are they trying to shoehorn all this stuff which has no real-world analogue into a model of the world? How does a Gantt chart work in this crazy place? Is it like some set of blocks which represent tasks which when I throw up into the air twists around like a Transformer toy into a diagram representing a critical path analysis?
You're right, there are areas where 3D doesn't make much sense. But as a file manager I think it might work reasonably well. Picture something like this:
A file is a solid column. The shape of the base tells you what type of file it is - triangle for regular file, square for block/char device, hexagon for socket/fifo, etc. The height of the column (log 2) tells you the file size. The texture of the column tells you the detailed file type (MIME type?) - movie, text, html, whatever. The color tells you what permissions you have on that file. (If it's a symlink, it has all those properties but is transluscent.)
Files are in a rectangular room, representing a directory. One wall has a door to the parent directory, the opposite wall has doors to the subdirectories. A third wall has a map of the filesystem on it, with "You Are Here". The last wall has a button on it - hit that button, the wall drops down, and you see the hidden files and subdirectories. The texture of the walls and floor of the room represents the filesystem type - FAT, ext3, SMB, etc. The color of the room tells you what permissions you have on that directory.
You can switch "tools" like in an FPS - maybe a shotgun deletes a file. (See here for an example of this.) Normal WSAD movement, but if you alt-click on something, you 'teleport' to it. So you don't have to walk all the way across a huge directory to get to a subdirectory - if you can see it, you can jump to it.
I've been slowly working on something like this, but I have three kids and one on the way - no time. If anyone wants to implement it, feel free.
That means that the 'millimeter-wave radar' that Hiro used in Snow Crash was operating at 300GHz. Basically in the 'microwave' range. Wonder how much power it put out?
Well, 2.4GHz is about.125 meters (call it 300/frequency in MHZ), so 1/8th of a meter or so. Things on a human scale would look pretty fuzzy and weird, but not completely unresolvable - you could definitely see pretty well where your wifi sources were.
60Hz wiring would be so fuzzy as to be useless... but what if you plugged in a little gizmo that put a nice high-freqency signal on the line? That could actually be useful, though it'll be a long time before something like that's practical or remotely cost-effective.
You could also use it to spot 'interference' on particular frequencies, and at least get a rough idea where it was coming from - the direction at minimum.
...don't have the teachers tell all the kids that homosexuality is all right and just an alternative lifestyle. If they are allowed to do that, they it's not the religiously-neutral public school we should have.
Teaching the fact that homosexuality exists and is observed in essentially all mammals is not the same thing as teaching that it's "all right". On the other hand, should schools be involved in teaching morals at all? If so, which ones? If not, what do you do about, say, bullying?
On another note, is there any justification besides a religious one that says homosexuality is anything but "all right"? That's where Orson Scott Card lost me with his little treatise about homosexuality - where he says 'Laws against homosexual behavior should remain on the books'. The whole article has basically been saying that he considers homosexuality bad because his church says so, and if you don't want to follow the church, leave it. So far, I have no problem with that. But then he wants his church's standards to apply even to people not in his church. Um, nope. Not just because the church says so, anyway. If they can offer some kind of evidence that such laws would be a good idea, maybe.
I'm not aware of any solid evidence that homosexuality per se is bad. About the only thing I can think of is the somewhat higher transmissibility of STDs given typical male-male sexual practices - but the opposite is true of lesbian activities in general.
Same thing for evolution : if it's taught, I don't have a problem with that as long as the present evidence against it as well as in favor of it.
I imagine a world where Windows is banned and replaced with Ubuntu (for the sake of argument). Imagine your family installing and updating software from CLI or giving up your favorite software or games.
Already done for my parents. I had them on Firefox and Thunderbird anyway, and moving them to Ubuntu was pretty painless. A short breaking-in period, but mostly they've been happy and I enjoy actually spending time with them when I visit now instead of working on their computer. The main thing they noted was that Linux had cooler screensavers.
A bit more complicated moving my wife and kids over, it's true. (Windows is corrupting its own system partition; no SMART errors detected, but booting is hit or miss now. No problems in Linux on the same machine.) Web and email are pretty much there, except for the Flash/Shockwave games the kids play sometime. I used this howto which works but is still a bit slow. Hopefully the native Flash 9 in "early 2007" will be better in that regard. A lot of the Windows educational games don't work so hot in Wine, but I'm playing with Qemu and VMWare player. Besides, they do like many of the Linux games available, so it's not so bad as all that.
My wife isn't quite as happy moving from MS Word to OpenOffice Writer. I've got all the fonts moved over but things don't work quite the way she's used to, and little format changes happen when moving between MS and OO formats. Hopefully this will pass, but it is a bit of an annoyance for now.
Imagine relearning all they know about their desktop in a Linux environment.
That has not been a problem, actually. For anyone - my young kids, my elderly parents, my thirtysomething wife. Desktops are pretty much desktops, and everything has its own little interface nowadays - cell phones, DVD players, stereos, practically every single website, etc. Learning another slightly different interface isn't a big deal.
Windows also has a lot of software not offered on other platforms, such as Photoshop, Flash (the IDE), Dreamweaver, 3DSMax and so on.
My family doesn't use those. Neither do I, for that matter. I do programming, not web development.
Perhaps if I were more of a web developer I'd see things your way.
First, terminate actions that are self-evidently counterproductive, above all by extricating ourselves in an orderly way from Iraq.
Second, revive in modified form the Cold War principles of containment and deterrence, incorporating explicit security guarantees for Israel, much as the United States has long guaranteed the security of Europe, Japan, and South Korea.
Third, initiate a new Manhattan Project to develop alternative sources of energy, thereby increasing US freedom of action and reducing the flow of wealth to the Persian Gulf, wealth that ends up subsidizing the Islamist cause.
Fourth, through police action, in collaboration with our allies, redouble efforts to dismantle the organizations comprising the radical Islamist network.
Fifth, patiently nurture liberalizing tendencies within the Islamic world, not by preaching or threats of regime change, but by demonstrating at home and inviting Muslims abroad to witness, the manifest advantages of freedom and democracy.
This alternative strategy will also entail costly exertions over a long period of time. Unlike the current ``war on terror," however, it promises to be affordable and sustainable, while holding out the prospect of delivering success in the long run.
Of course, I don't think any of the other browsers have something like this going on. Automatic
code analysis will turn up bugs for anyone, but nobody else makes the code so public.
Everything the humans do in that movie is either real tech or plausible extrapolations from research being done at the time the movie was made. That rat really did breathe fluid. (Unfortunately, it doesn't work so well for humans. The fluid is dense enough that moving volumes of it in and out of human-size lungs is too much work for the oxygen it can provide. Given a version that was less dense, or held a lot more oxygen...)
Sure, the aliens do a bunch of magic, but hey, they are supposed to be more advanced than us. Look around where you are right now, and I bet you could find five things that would be 'magic' and 'impossible' to people even a century ago in 1906. (Start with the computer you're reading this on.)
Sadly, I have a hard time coming up with much more. Maybe The Manhattan Project isn't too far off. Several things in it are (ahem) highly implausible, and the specific design chosen wouldn't work, but nothing that's actually physically impossible happens.
It might have been as most frequent business travellers given the chance will not take a window seat because it is a major pain to keep getting up and down for the bathroom.
So good bladder control is a sign of incipient terrorism? I'd have thought the reverse...
Travelling on business to Ireland for the third time in a year and half. Checking in at the Detroit airport, I ask them to make sure that my bags are checked through to my final destination, since I'll be making a stop. I'd had a very bad experience on my return trip six months prior and nearly missed my connecting flight home because of it.
The guy does so, then looks at me and offers to move me to a window seat. I say, "Sounds good" and hand back the boarding pass I've already received. Sure enough, the one I get back has a bunch of S's drawn on it. I get the VIP treatment at security, of course.
So, was that question really a big terrorist tipoff or something? Or did I just irritate the guy a bit and he decided to have some fun with me? And either way, am I supposed to feel safer?
The original design was to be actual nuclear weapons.
Um, yeah, I know, I was just pointing out that other technologies available to humans besides "exploding bombs behind the spacecraft" can lift similar amounts. The one I linked to basically uses a nuclear reaction to heat up hydrogen, which can't be made radioactive, and spewing that out the back. Great for liftoff from Earth.
For operation in space, I think you're referring to this, which has highly radioactive exhaust but a wonderful ISP.
Slashdot Mirror
Aw, you didn't mention Larry Niven or Robert Forward!
I never claimed to have invented all or even most of the concepts there, and I thought I did pretty well to give credit to those who did. I do think the section on "Practical Consequences" is relatively novel, though. If you're trying to obliquely quote Samuel Johnson at me, well, everyone has their own taste.
Um, it very specifically says that's one alternative, not the only possibility. Of course, this is Slashdot - who bothers to RTFA? (Oh, and it doesn't claim to have 'invented' it, either.)
What if causality is a local condition and not a global one? Perhaps our intuitive understanding of causality only applies to regions without closed timelike curves, just like our intuitive notions of physics only apply to macroscopic objects moving slowly relative to light. Like a fish that had always lived in a smooth-flowing stream, and never encountered turbulent flow.
Boy, that went right over your head. Since elaboration is clearly necessary, I will spell it out: No, you didn't say that. But what you did say was in the same class as the statements I listed.
What if the Everett Interpretation of quantum mechanics is correct, and time-travel simply allows access to (or creation of) alternate worlds? In which case, there's no 'paradox', because in the case you propose (seeing a signal and then not sending it) you are in an alternate universe already and your action will, at most, simply prevent another alternate universe from being created.
But causality itself is rather more complicated anyway if you assume time travel is possible at all. We normally see effects coming after causes, but the very definition of time travel is effects coming before causes. And we have reason to believe it may well be possible. In a region where space is heavily twisted around (e.g. around a spinning black hole, and we have observations that strongly indicate (a) the existence of black holes, and (b) that they spin) the very straightforward calculations of GR show that closed timelike curves (time travel, basically) arise naturally.
We can imagine that our universe consists of three-dimensional moments arranged in a four-dimensional sequence. Even if we walk in a circle, we haven't returned to the same point - it's the same point in the three space dimensions we normally use, but it's displaced in the fourth, time dimension.
Note that this is exactly the model used by General Relativity. The universe, which we normally think of as being made of "space" and "time", is actually a single something called "spacetime". In Einstein's view, the world really is a static four-dimensional 'sculpture', and time really is, in a real sense, another measure of distance. Time normally proceeds at the speed of light - one second ago is one light-second (186,000 miles; 300,000 kilometers) away. As Einstein himself said, "Past, present, and future are illusions, if stubborn ones."
So it may be that if you receive a message from the future, you can't prevent it from being sent - from your perspective, anyway. If you receive the message, you obviously know it'll be sent - but you don't know that it was you that sent it, for example. Maybe you don't turn on the machine... but someone else does, or turns on a different machine somewhere else, etc. In such a model (totally consistent with GR, I'll again note) the future is exactly like the past - some things can be known about it, but some things you don't know.
Gee, you're right! Nobody ever, ever thought of that and proposed ways not precluded by our current understanding of physics to do those things! What strikingly original thinking you display! :->
Simple geometry shows that FTL travel or communication leads directly to time travel.
Yeah! And time can't slow down when you go close to the speed of light! And things can't act like both a particle and a wave! And particles can't tunnel through barriers they don't have the energy to escape!
For that matter, I'm not at all sure about these magical "fields" that act at a distance. And this whole "germ theory" of disease makes no sense - clearly it's just miasmas!
(Hint: you have not come up with a brand new objection to time travel, or even one that hasn't been answered before.)
No, that's not a paradox. A "paradox" is a self-inconsistent set of circumstances - like killing your grandfather before you were born. What you're describing is something different; it is internally consistent, but depends on effects preceeding causes. (I like Andrew Plotkin's term for them - "perpendoxes", because they are orthogonal to paradoxes.)
Of course, that's the definition of time travel - if you don't have "effects preceeding causes" you don't have time travel at all.
It does seem weird that information could be created "out of nothing", but we didn't evolve around time travel. We didn't evolve around relativistic speeds and that seems unlikely and counterintuitive, too. We are used to thinking of things in a linear, cause-and-effect order, but you'd pretty much have to expect unusual things in a situation where that didn't apply.
Note that if you have time travel at all - if you can actually "travel to the past" (or make a photon do it) - then the past must actually exist somewhere. As a matter of fact, in relativity it does - one second ago is physically one light-second away. But that would also mean that the future already exists - since every moment is past to some moments and future to others.
Anyway, here's the lowdown if you want it in excruciating detail.
That's like saying in 1870 that radio waves are impossible because nobody's received any. There weren't any receivers then. Or like saying neutrinos didn't exist before there were detectors for them. It's quite possible that the as soon as we have something that can receive such messages it'll be flooded with spam from the future.
Anyway, I've thought about time travel rather more than anyone probably should, if you're interested. I address that point and a lot of others.
For a summary of why the movie was nothing like the book, see here.
Yup, a cluster of PS2's running Linux.
Nah, when it plays the music via CD it's just using the SDL calls to start the CD playing analog, not via the digital interface. And in the one case, I don't even have the CD in at all and the framerate's still slow. But if I have the game load up an Ogg version of the song and play it in the background, something that should take more CPU, the framerate goes up. It's really weird. I'm not even sure how to debug it.
So, no CD - slow. CD playing - slow. Ogg music - fast. WTF?
My current theory is that OpenAL's AL_EXT_VORBIS extension uses a hidden thread and some interaction there lets the game proceed. But that's just a guess. Anyone ever run into something like that?
In the "Gold" edition the programmers got to indulge their vanity and re-record the in-game FMVs themselves. An excellent example of why you should hire actors to do acting. The same lines, same framing, same lighting... but the "Gold edition" FMVs sucked compared to the originals.
(Fox/Rebellion released the source code and icculus ported it to Linux. (The cvs link there doesn't work, you need to use Subversion to get it.) It didn't link for me on Ubuntu, so I patched it. Unfortunately, the videos are in a proprietary codec (Bink/Smacker) and now I'm working on restoring them to the game. Looks like recent libavcodecs support that format... :-> )
That's actually the primary use I've figured for it, as an introductory/educational tool. As people gain experience, they'll tend to use 2D or even 1D (command line :-> ) interfaces, but as a simple, relatively intuitive interface it has its advantages. People have hardware in their brains for quickly judging the shape, size, color, and material of an object, and for navigating by landmarks and such.
Note, too, that you could have a "home room" with doors leading off to commonly-used directories and an area with symlinks to the most-recently-used files, etc.
(And yeah, it'll need a lot of tuning to be aesthetically coherent. But I don't think it's quite so insurmountable as you say. :-> In any case, it might at least be an educational failure.)
You're right, there are areas where 3D doesn't make much sense. But as a file manager I think it might work reasonably well. Picture something like this:
A file is a solid column. The shape of the base tells you what type of file it is - triangle for regular file, square for block/char device, hexagon for socket/fifo, etc. The height of the column (log 2) tells you the file size. The texture of the column tells you the detailed file type (MIME type?) - movie, text, html, whatever. The color tells you what permissions you have on that file. (If it's a symlink, it has all those properties but is transluscent.)
Files are in a rectangular room, representing a directory. One wall has a door to the parent directory, the opposite wall has doors to the subdirectories. A third wall has a map of the filesystem on it, with "You Are Here". The last wall has a button on it - hit that button, the wall drops down, and you see the hidden files and subdirectories. The texture of the walls and floor of the room represents the filesystem type - FAT, ext3, SMB, etc. The color of the room tells you what permissions you have on that directory.
You can switch "tools" like in an FPS - maybe a shotgun deletes a file. (See here for an example of this.) Normal WSAD movement, but if you alt-click on something, you 'teleport' to it. So you don't have to walk all the way across a huge directory to get to a subdirectory - if you can see it, you can jump to it.
I've been slowly working on something like this, but I have three kids and one on the way - no time. If anyone wants to implement it, feel free.
That means that the 'millimeter-wave radar' that Hiro used in Snow Crash was operating at 300GHz. Basically in the 'microwave' range. Wonder how much power it put out?
60Hz wiring would be so fuzzy as to be useless... but what if you plugged in a little gizmo that put a nice high-freqency signal on the line? That could actually be useful, though it'll be a long time before something like that's practical or remotely cost-effective. You could also use it to spot 'interference' on particular frequencies, and at least get a rough idea where it was coming from - the direction at minimum.
Now, what would an UWB device 'look like'?
Teaching the fact that homosexuality exists and is observed in essentially all mammals is not the same thing as teaching that it's "all right". On the other hand, should schools be involved in teaching morals at all? If so, which ones? If not, what do you do about, say, bullying?
On another note, is there any justification besides a religious one that says homosexuality is anything but "all right"? That's where Orson Scott Card lost me with his little treatise about homosexuality - where he says 'Laws against homosexual behavior should remain on the books'. The whole article has basically been saying that he considers homosexuality bad because his church says so, and if you don't want to follow the church, leave it. So far, I have no problem with that. But then he wants his church's standards to apply even to people not in his church. Um, nope. Not just because the church says so, anyway. If they can offer some kind of evidence that such laws would be a good idea, maybe.
I'm not aware of any solid evidence that homosexuality per se is bad. About the only thing I can think of is the somewhat higher transmissibility of STDs given typical male-male sexual practices - but the opposite is true of lesbian activities in general.
"[E]vidence against it"? Such as?
Already done for my parents. I had them on Firefox and Thunderbird anyway, and moving them to Ubuntu was pretty painless. A short breaking-in period, but mostly they've been happy and I enjoy actually spending time with them when I visit now instead of working on their computer. The main thing they noted was that Linux had cooler screensavers.
A bit more complicated moving my wife and kids over, it's true. (Windows is corrupting its own system partition; no SMART errors detected, but booting is hit or miss now. No problems in Linux on the same machine.) Web and email are pretty much there, except for the Flash/Shockwave games the kids play sometime. I used this howto which works but is still a bit slow. Hopefully the native Flash 9 in "early 2007" will be better in that regard. A lot of the Windows educational games don't work so hot in Wine, but I'm playing with Qemu and VMWare player. Besides, they do like many of the Linux games available, so it's not so bad as all that.
My wife isn't quite as happy moving from MS Word to OpenOffice Writer. I've got all the fonts moved over but things don't work quite the way she's used to, and little format changes happen when moving between MS and OO formats. Hopefully this will pass, but it is a bit of an annoyance for now.
That has not been a problem, actually. For anyone - my young kids, my elderly parents, my thirtysomething wife. Desktops are pretty much desktops, and everything has its own little interface nowadays - cell phones, DVD players, stereos, practically every single website, etc. Learning another slightly different interface isn't a big deal.
My family doesn't use those. Neither do I, for that matter. I do programming, not web development. Perhaps if I were more of a web developer I'd see things your way.
http://www.boston.com/news/globe/ideas/articles/20 06/08/27/no_win/?page=full
Of course, I don't think any of the other browsers have something like this going on. Automatic code analysis will turn up bugs for anyone, but nobody else makes the code so public.
Sure, the aliens do a bunch of magic, but hey, they are supposed to be more advanced than us. Look around where you are right now, and I bet you could find five things that would be 'magic' and 'impossible' to people even a century ago in 1906. (Start with the computer you're reading this on.)
Sadly, I have a hard time coming up with much more. Maybe The Manhattan Project isn't too far off. Several things in it are (ahem) highly implausible, and the specific design chosen wouldn't work, but nothing that's actually physically impossible happens.
So good bladder control is a sign of incipient terrorism? I'd have thought the reverse...
The guy does so, then looks at me and offers to move me to a window seat. I say, "Sounds good" and hand back the boarding pass I've already received. Sure enough, the one I get back has a bunch of S's drawn on it. I get the VIP treatment at security, of course.
So, was that question really a big terrorist tipoff or something? Or did I just irritate the guy a bit and he decided to have some fun with me? And either way, am I supposed to feel safer?
Um, yeah, I know, I was just pointing out that other technologies available to humans besides "exploding bombs behind the spacecraft" can lift similar amounts. The one I linked to basically uses a nuclear reaction to heat up hydrogen, which can't be made radioactive, and spewing that out the back. Great for liftoff from Earth.
For operation in space, I think you're referring to this, which has highly radioactive exhaust but a wonderful ISP.