The fact is, the Hubble and JWST instruments are *complementary*
Complementary would mean they don't overlap. They do. Significantly. JWST is optimized for infrared, because it's a deep-field utterly huge telescope for looking at gigantically distant things, but it reaches all the way to green.
neither does any other telescope currently available
Look, Hubble isn't perfect for UV. They've been planning on doing science in the UV without Hubble for many years now. It's not worth spending the money on Hubble rather than spending it on a telescope specifically designed for UV that doesn't overlap with JWST.
Also, I have never heard NASA say that the Hubble is just old and worn out. They say it's too risky to go up for another servicing mission.
It's not too risky. They could do it if they wanted to. They'd simply have to recertify the shuttles specifically to do it, and what they're saying is that the excess cost to do that is not worth the limited science that Hubble would do in the remaining years it has left.
In other words, Hubble is too expensive to keep running. That makes it uneconomical now.
The main problem with the controversy is that there are emotions involved, and that makes for very bad decision-making. Any of the advocates for Hubble always push the emotional attachment to Hubble, rather than the simple by-the-numbers math.
The only space telescope on the drawing board is the James Webb scope, and it's an IR scope. There's nothing even in the planning stages for a replacement for Hubble.
You're wrong. The JWST will cover some of the optical, just not up through blue. Why?
Because the optical is boring. Scientifically, it's not interesting. Deep-field objects are redshifted, and so naturally a big telescope will concentrate on the longer wavelengths.
Besides, go look at some of the pictures that Spitzer has put out. They look gorgeous. They're fake color, sure, but who cares? In fact a lot of this stuff is redshifted, as I mentioned, so you're not even looking at it in "real" light anyway.
The JWST is a replacement telescope to Hubble. Some features of Hubble's - like the ability to see in the blue band - just isn't that important for science right now.
and it'll keep going happily for a long time to come yet.
This is, of course, naive. Hubble is a space telescope, and it's already pockmarked from space debris. It's just a matter of time until Hubble is damaged beyond repair.
but suggesting that it's the most user friendly interface is, again, just stupid.
What's the pinnacle of user-friendly design? Most people would hold up the unattainable "Star Trek computer" as the pinnacle - "Computer, do this." "Computer, do that", and it just works. If you expect a response to your command, the computer speaks it to you.
That's a vocal version of a command line.
Simply put, it's more intuitive. And, quite frankly, it's easier to learn young: I started learning how to use a computer when I was 4, but there's no way I could've used Windows now when I was 4 - the manual coordination wasn't there (and yes, I learned to read young).
I don't understand why command lines are given the bad rap they are. If you're trying to say that "grep Mike files | awk {'print $2 $3'} | sed s/form/from/" is too difficult to learn, I (might) agree with you. But a prompt where you just type "find all files containing Mike, print second and third word, substitute from for form, print results." is not user-unfriendly. It's nearly perfect, in fact.
Much easier than "Click on Find. Click on 'Options'. Click on 'Output'." etc. etc.
The problem may be that the command line is too immature to be generically useful. True. But it is not a poor UI. Its main limitation - needing to know a vocabulary - is an implementation issue, because natural-language parsing isn't good yet. It's not a UI problem.
I'm glad you brought up the stick-shift, because I almost did last time. Guess what? In order to learn how to drive, I don't need to learn how to put a car into 2nd, or even 1st, with a stick shift. I can just put the big dumb circle over the big D and hit the gas! Wow! Not only do I not need to know all about gears, carberators, brake lines, etc., I don't even need to know how to drive a manual. The fact that it might be better is not the issue, it's what is easiest for 95% of the users.
Here's the interesting thing - only in the US is automatic transmission dominant. Pretty much everywhere else, manual dominates massively, and the reason is because manual transmission is simply better than automatic, and the learning curve is not that high. I doubt the people in those countries would claim that manual transmissions aren't "user-friendly". If the excess power justifies a learning curve, it's not "user-unfriendly".
I guess what I'm saying is that in my opinion, a user-friendly operating system needs to minimize the frustration of the user. With Windows (and Microsoft products), it just doesn't do that. If you're Bill Gates, it probably works fine, but for anyone who uses real products, it's a pain.
But anyway, the point is that your opinion of user-friendly is "make the common things easy", and that's not mine, because while it makes people happy when things work, the fact that you can't fix things, nor can you even figure them out, means that not only will ordinary users occasionally get frustrated, but power users will too!
Could you imagine if my brother and mom asked me "Hey, can you figure out why my wireless network card is acting weird?" and I just told them "Um. Well, Windows is broken. There isn't really a way to make it work." Remember, as far as they know, I'm the expert. This would be like a car mechanic saying that you're going to have to live with some weird "clunking" sound because there was no way to inspect the engine and figure it out!
To think that an average computer user is going to learn enough to script an auto DHCP release/renew is simply absurd.
I never said that. I said I could. If my mom needed me to, I could do it. You yourself said it - pay an expert to fix any problems. All the people who are whining about how hard it is to install a network card in Linux - why don't they just ask an expert?
Now would someone tell me how to make Windows' DHCP requesting work properly with wireless network shifts? Oh, wait! There's no way to do it! And, for more fun, I can't even pay a smarter expert to fix it, because they've already told me that they don't know, either! And Microsoft? 3 emails down, no responses yet!
Keep in mind, all I'm trying to do is make wireless networking work. If this was a common user, all they would know is that it doesn't work. Not that the DHCP release isn't working. In fact, before I knew about ipconfig, I had to physically remove the network card to get it to work. Now that I've got an integrated wireless card, I couldn't even do that. I have no idea what I'd do. Rebooting doesn't even work.
(And, for what it's worth, the DHCP release/renew daemon is already written in Linux - it's called ifplugd/waproamd, and it's heavily commented, and heavily documented.)
Let me put it this way: suppose someone can't get something to work under Linux. What do they do? Well, they could whine and complain, or they could post a message on one of many mailing lists or message boards saying "hey, this doesn't work. Anyone got any ideas?" Chances are they'd get information back very soon giving advice or, regretfully, telling them that they don't have much luck (although DriverLoader may hopefully make the driver issue moot - and yes, Windows driver emulation is a good thing in my opinion).
But what they would not be is left out in the cold, which is where they'd be if they were in Windows.
(frictional forces on the ribbon through atmosphere) and the entire system will eventually burn up in re-entry (loss of orbital momentum due to dragging 100k km of ribbon through atmosphere).
Wow, I didn't even notice this the first time through.
The elevator is stationary with respect to the atmosphere. Why would there be any friction on it from non-moving air?
This is not a troll. This is pointing out that one of the main benefits of Linux over Windows is the fact that it's open. There's information out there about it. You can learn how to do almost anything, and the operating system encourages you to do it.
Windows doesn't - it forces you into the Microsoft mindset. Anything outside of that is very, very hard to get around. It's very "closed". And that's why I get very annoyed at people who insist that Linux needs to become more like Microsoft, and "hide" things.
His point is that anyone could have set it up under WinXP in two minutes.
Ha! My mother-in-law, mother, or brother couldn't've set it up in WinXP in two days. They don't know where to start.
Us telling them "Move the mouse to the Start menu, click the left mouse button, then up to where it now says 'Settings', then over to where it will then say 'Control Panel', then click the left mouse button." and us telling them "Press Ctrl, Alt, and F1 at the same time. Type your username and password. Type "etherconf", and follow my instructions" is just as easy - in fact, as you can see, it actually takes less instructions. (Actually, if you really need to set up TCP/IP settings in Windows, it can be quite complicated for someone who hasn't used a computer before, because a lot of the interface is crazy: when you enter an IP address, you have to be very careful, as it barks at you if you even try to enter in anything greater than 255. This is dumb - it should tell you this after you enter the entire thing in and try to apply it. It slows the process down, and it frustrates the user - especially one who needs to look at the keyboard to type - that is, someone new)
If you're talking about Windows XP's autodetecting new hardware, it should be noted that Mandrake and Red Hat both have autodetect/autoconfigure mechanisms as well. And Windows XP's behavior when it can't find a driver is often times insanely stupid, and it doesn't make anything "easier" to a user.
Frankly, I think you're misappropriating the term "user friendly".
Take two people who don't know anything about computers whatsoever. Give one a computer with Windows, and one a computer with Linux. Give them both access to customer support and help. Now wait a year, and see which user is more proficient and knowledgeable about their computer.
The OS with the more procifient user is more user-friendly, because it helped them be as productive as possible. Whether or not it was easy isn't the whole story. People use computers to be more productive, not just to use them. An OS that fights with its users because it thinks it knows best isn't user-friendly.
They've learned the Desktop/Folder paradigm.
And how is that user-friendly? It actually artificially introduces a lot of things which aren't true, like only the things that are on My Desktop are easily reachable. (Windows XP, by default, discourages access to the hard drive directly).
In fact, it's "user-harmful", as it presents a paradigm to people that the rest of the computer doesn't really follow.
It also discourages people from learning how to type, as almost all of the interaction is via the mouse, and the productivity using the mouse is far worse than using a keyboard.
Try realizing that you and (likely) the people you know are not average.
I don't have that much of an ego.
There are very few people I know who wouldn't be able to learn what I know in just a few months of learning. The point that I'm trying to make is that Windows discourages people from learning how a computer actually works - it hides tons of things for no good reason. This isn't "user-friendly" behavior. There's no good documentation for almost everything - there's more bad documentation than good. "Clicking the 'Close Window' button closes the window." Yah, that's useful documentation.
This statement is completely opposite to the laws of thermodynamics.
No, it isn't. The best description of the laws of thermodynamics that I've heard is (yes, I know what the actual wording is, but I think this better describes the effects:) )
1: You can't win. 2: You can't even break even. 3: You can't get out of the game.
None of these say "you can't play really, really bad." It just limits how good you could possibly play, if the Universe was fair and everything was perfect. Remember that no one can actually build a practical Carnot engine - we're forced to use the far less efficient Otto cycle, and people dream of using the Stirling cycle, which is better, but still not Carnot.
The hotter your heatsource is, the more efficient you can do work with it.
Not really. The hotter your heat source is, the more the maximum efficiency you could ever reach gets. That doesn't mean you practically can do more work with it.
The best example would be neutrinos: a neutron star gives off a tremendous amount of neutrinos when it's first born via the URCA process (neutron->neutron + electron neutrino + electron antineutrino, via inverse beta decay+beta decay) - more energy than the Sun gives off in its entire lifetime. But it's nearly impossible to convert any of that energy into work, because neutrinos barely interact at all. The volume of the "block" that heats up would probably have to be the volume of the entire solar system, and therefore it would barely heat up at all because of the huge heat capacity, and (by the second law of thermodynamics), your efficiency of conversion is terrible.
Similar things happen here: many forms of radiation are very hard to absorb, and therefore there's no practical way to convert back into useful work. Sure, you could try to absorb the radiation and heat something up that way - but the conversion efficiency would be terrible, since most of the betas and gammas would zip right through your absorber, and only deposit a small fraction of their energy, which means the engine you finally build will have even worse efficiency.
The big problem is to get some energy out of heat with a lower quality
Huh? Heat is heat is heat is heat - it's kinetic energy of particles moving around, and it's all of the same "quality". It's not sunlight. Sunlight is light, and conversion efficiencies of sunlight -> work are actually not bad. Hence the whole solar power thing.
The cable is attached to a weight that rests on the earths surface, (or on the ocean). This weight weighs much more than any climber that is to go up the ribbon, in fact it weighs more than the cable can support, so if it was over a hole the ribbon would fall to earth, however because the earth's surface will support any weight that the ribbon does not the system is in equilibrium.
What the heck are you talking about? The cable is in orbit - it's not "resting" on the Earth's surface at all. When a climber's not on the cable, the cable just hangs there. It wouldn't have to be tethered to anything at all. (Why would it? It's in orbit - satellites in geosynchronous orbit aren't tethered to anything, and they just hang there, and that's all that a space elevator is!)
When a climber pulls on the cable, the part below the cable slacks slightly because the cable starts "pulling" to the east, because its center of mass is now too low, and the orbit is faster than geosynchronous (i.e. toward the earth and westward. This is where the climber gets its angular momentum from, because it's slowing the Earth's rotation down. The slack in the cable is determined by the Young's modulus of the ribbon - i.e., how much the cable "stretches" under load.
If the cable were to break at the base, the cable would start drifting eastward, very slowly. With the climber on, the ribbon is too heavy - it doesn't head outward, it heads inward. It doesn't fall, of course, because it's in orbit - it just starts dragging around the globe in an elliptical orbit, very slowly. When the climber lets go, the ribbon slowly moves upwards back into a geosynchronous orbit, and from the Earth's frame, it stops moving. It might actually start moving around a little bit due to odd extra components.
If there was no tension in the cable it would be impossible to attach a climber.
There is tension in the cable without it being tied to the ground! Tension due to gravity - several thousand tons of tension!
only force the climber could act against would be the inertia of the system, and that means accelerating it towards the ground.
By your argument, any satellite could never stay in orbit. It is constantly accelerated towards the ground, but it's also got a tangential velocity sufficient to keep it in orbit.
Look, this is simple orbital mechanics. Ignore the fact that the ribbon's an extended object - just concentrate on the movement of the center of gravity, which is at geosynchronous orbit. When you add a climber, the c.g. moves down, so the orbit speeds up. When the climber lets go, the c.g. moves up, so the orbit slows down.
That is why you would first need to increase the mass of Mars, that is, create a new planet by tossing a few spares together. Mars, Venus, maybe some of Jupiters moons (Europa could be the iceing on the cake). Just got to make sure the pieces stay together and wait for it to become stable. It would clean up this star system some to boot.
Mars slamming into Venus would probably generate an Earth-Moon system pretty similar to what we have now - the Earth would be a little larger, the Moon would be a little bigger, but it'd be about right.
Venus is 90% mass of Earth, Moon is about 1%, and Mars is about 30%. They'd be all you need.
It would also generate a magnetic field on Venus, very likely, as Venus's problem is that it doesn't spin fast enough. The collision would also strip large portions of the dense atmosphere away, and with the rapid spinning, a thermal equilibrium would probably quickly form.
Venus's lack of rotation is probably the only real significant inhibitor to terraforming it.
However, I think it's a waste of resources using mass as a source of gravity
Why? Mass is the most efficient way of storing energy in the known Universe, and you need energy to generate gravity. Seems to me that mass is pretty ideal.
No, it isn't. This is where the research was 50 years ago when people were still trying to understand the EPR experiment. It's pretty much understood now.
If we can influence the level/wavelength/quantum parameters (e.g. spin) of a particle, we can *instantaneously* influence the energy of a particle some distance away.
That's the problem. You can't influence the determination of the outcome of the first experiment - the first determination of the spin. It's random. By definition. Random. And that's because it was determined by a random process. There is no way you could influence it, any more than an observer can influence a shadow. It was generated by a process that, if you could influence it, would eliminate any benefit of influence.
Interestingly, a lot of research is also being done into non-intrusive measurement, a method by which they can measure the state of an object without affecting it too much.
You're not understanding what they're doing. There is no way to measure certain things - like the Z-dir spin of a particle - without affecting it. That's because the Z-dir spin of a particle is determined by interactions, so interacting with it is (obviously) going to change it! There are ways to determine certain things about a state without affecting others, but that's because those variables aren't complementary.
Also, you might want to look at the results of the quantum teleportation experiments from a year or so ago, where they did indeed 'force object B's measurement to have a desired result' by superimposing a quantum wavestate of an existing photon over a new photon, effectively teleporting the photon.
That is not what happened there. What happened there was that they "teleported" the original photon by recreating its state later. You cannot do the same thing with an entangled photon. Can't. Not "can't because of some pre-established rules". Can't because it's already been proven that you can't.
Personally, I favor the latter. Specifically, if you look at some aspects of multidimensional theory, then it's feasible that the entangled particles are not violating the speed of light (provided you assume more than three dimensions, a la superstring theory.)
They're not violating the speed of light in normal quantum field theory - the Z-dir of spin is not something that's intrinsic to the particle, but conserved within interactions. It's a quantum shadow, nothing more, cast by interactions on a particle with spin.
Imagine someone with a normal flashlight, that spreads out as it gets farther. Now imagine that same flashlight seen on the Moon. Let's say, for the sake of argument, that it encompasses the full Moon's area. Now imagine someone moving their finger across that flashlight, and picture what that shadow does moving across the surface of the Moon. It moves across the Moon's area in a fraction of a second, which could be many times more than the speed of light on the surface. This isn't amazing, or surprising at all - there is nothing physical about that shadow at all. It can't convey information from one point on the moon to another, only from Earth to the Moon, which it does at the speed of light.
For a better description, with the proper math, of what I'm saying here, check Griffith's appendix on the EPR Paradox and Bell's theorem in "Introduction to Quantum Mechanics."
Yes, I believe the "hidden variables" approach to QM is correct -- it's not such a stretch for me to believe that all of the properties of a particle are set at definite values at any given instant. It's just that proving it (and it does require proof) is as difficult as proving that particles actually physically influence each other instantaneously over distances. But, the hidden variables approach doesn't violate causality and makes sense and until proven otherwise it seems to be the easier to believe.
Er? It was proven otherwise - by Bell's theorem. Hidden variables simply produces a different answer than QM - a *wrong* answer, based on experiment. The only assumption was that the variables are local. If you go to a global hidden variable theory, you'll violate causality.
The problem with what both of you are discussing is the fact that you're assuming that, for instance, the z-orientation of the "spin" of a particle is a "real" thing, something that every particle "must" have. This is the part that doesn't have to be true. The z-orientation of the spin of a particle is determined only by its relation to other particles, which is determined only by interactions. Those interactions need to conserve the quantities we observe (since they're *based* off of the symmetries that generate those conserved quantities) and so, you get "entanglement" to preserve those quantities. It's just a mathematical artifact to say that they "instantaneously influenced each other" - wavefunctions aren't directly measurable, because they're just math. The only thing that's "real" about a particle are its mass, spin, charge, and color (as in quantum color). Everything else - position, velocity, etc. - are all generated by interactions.
"FTL effects" are nothing new - I don't know why people think they are. ("Quantum" makes people go "ooh" apparently - though how quantum field theory could violate something it's based on, and still be consistent, should make people's eyebrows raise) An amazing, complicated effect known as a shadow can exhibit "superluminal effects" - just imagine someone shining a flashlight at the moon, and moving their finger across it rapidly. The shadow cast by their finger will travel much faster than the speed of light at the Moon, because the distance covered is huge. But a shadow can't convey information from one point of the Moon to another, because they'd have to go through Earth first.
When the ribbon is cut in such a situation, the SE will go into an elliptical orbit.
Yes, but that's basically an academic scenario, because it will only *start* to go into an elliptical orbit. In any real-life scenario, the climber would immediately be commanded to let go (explosive bolts!). It should be noted we're also considering the elevator's CM as a point mass, which it isn't - cutting the ribbon, while loaded, would likely do very odd things, but it's unlikely that it would be unrecoverable things. It may make the ribbon oscillate wildly for a while, which could be very dangerous, but it would settle down within the course of a few days. The bottom portion of the cable would "sproing", and bounce, a few hundred km, probably, but the energy would dissipate rapidly. The elevator operators would definitely spool out significant amounts of cable to alleviate those issues.
So, I guess, to amend the above, if the ribbon is unloaded (if the lifted mass is located near GEO) then cutting the ribbon at the anchor will do absolutely nothing. If the ribbon is loaded (the lifted mass is located near Earth) then cutting the ribbon at the anchor will cause problems, but not unrecoverable ones.
But what is it exactly about water that makes it so important?
Actually, that web site you linked to shows a lot of properties that are generic to all liquids - the unique one being that water expands when it contracts.
However, the question should be "why only water?" and the basic answer to that is pretty simple.
Life, simply put, could be described as nature selecting out certain configurations from a system that contains an almost infinite amount of states. Therefore, you need something that allows for many states and many configurations to form - that is, you want a dipole - subatomic "glue", basically - something that can take ions and join them together in weird ways to get bizarre states. Dipoles also act simultaneously as solvents - that is, they break down objects into dissolved ions.
Well, if you want a dipole for life, then you're probably going to get life based on the simplest dipole available. So you start with hydrogen, the most common element. And the simplest dipole you can form with hydrogen is water.
This, of course, doesn't preclude other elements from being the basic dipole for life if the region isn't compatible with water - though, unlike what the article says, Earth is not at the triple point of water - the blackbody temperature of Earth is ~255K, which is far underneath the freezing point of water (granted, triple points require knowledge of pressure, which eliminates a simple blackbody approach, but...). Earth's atmosphere, however, is at the triple point of water, but that's because it's been tuned to get to that point by the various thermal cycles and biological cycles which keep Earth's temperature near that point. What you really needed was liquid water, because as a solid or as a gas, the dipole properties are really being wasted. So, one can imagine a world where something just slightly more complicated than water (say... ammonia) is liquid, and maybe, just maybe, you'd get a complex chemistry out of that, too.
So the cable stays taught because it has hairspray on it?
Sigh. I actually thought you might have read something about the space elevator concept.
The cable stays taut because of gravity. There is no tension between the cable and the ground. There is, in fact, no reason that the cable needs to touch the ground at all.
The cable remains taut because the center of mass is in geosync, and the inner cable needs to keep up with it - tension.
Imagine a spacecraft at geosynchronous orbit which extends 1 meter of cable downward, and 1 meter of cable upward. It, of course, stays at geosynch, because its center of mass is still at geosynch. Now have the spacecraft repeat that thousands of times, until the cable reaches near the Earth's surface. That's a space elevator. Don't think of it as interacting with the ground in any way. It isn't.
Cut it at the bottom, and it goes in orbit.
I'm sorry, but you're wrong. The cable already is in orbit. Cutting it at the bottom will simply move its center of mass infinitesimally higher, and will simply make it drift to the west very very slowly. Obviously it won't come back to the same place 24 hours later, so that part of the post was completely wrong. But cutting it at the bottom won't do anything. The cable will likely just sit there.
Ballparking some numbers: if you cut off the bottom 1 km of a 100,000 km cable, that will move the center-of-mass out about 0.001%. The cable's orbit was at a 24 hour orbit, and orbital periods go as proportional to the 3/2s power of the radius, so the period will increase about 0.001% (this is *really* ballparking). This means that the period increases by about one second per revolution. Something at the Earth's surface moves about half a kilometer a second while rotating (40K kilometers in ~ 80K seconds), so this means it moves about half a kilometer per day to the west. This means that it moves about 5 millimeters per second to the west.
Considering all they need to do is spool out 1km more cable downward, I think they might be able to recover it.
Though the orbit is geosynch, it isn't because of the distance of the center of mass of the thing. It's the distance of the center of mass of the thing while tied to the ground.
Um. No. The elevator most definitely wouldn't be "tied to the ground" in any significant way. It would be in orbit. Just like the ISS. Or the Shuttle. It just happens to be really really elongated as well, and one of its ends is near the surface of the Earth.
Cut the ribbon near the ground, and nothing happens. There's no tension against the ground - the tension is from gravity, along the object's length. Odd, and difficult to think about, yes, but absolutely one hundred percent classical physics.
Now, to correct myself - it would, of course, be tethered to the Earth. However, that would be for the sole purpose of damping out the natural 7 hour oscillation that comes from torquing a 100,000 km cable. And, of course, for compensating for an imperfect geosynch orbit, or a non-fixed anchor position (like a floating platform).
But then on my notebook I have to recompile my display drivers every fourth of fifth update, and I still haven't figured out why or when... heck, if I weren't a reasonably experienced user I probably never would've gotten the drivers going in the first place.
Pin the xserver-xfree86 release. Instructions on how are in the Debian User's Guide. That way it won't get upgraded, but everything else will. It should be noted that notebook video is *terribly* supported, but there are *plenty* of guides out there as to how to do it - tuxmobil has them.
(You also then should do the trick above which emails you changes specifically for the xserver-xfree86 release coming from the security dist.)
And as related to previous discussions, the reason that apt's better than Windows Update is that it allows you to customize in this way. With Microsoft, it's "You want to install these updates. Really you do. Trust in Microsoft. Believe Microsoft. Microsoft is good. Watch the spinning lights."
Seriously, why should she have switched? Linux has to offer something BETTER and DIFFERENT from Windows, not rip them off in the next KDE version.
There's the problem. She's just looking for Windows, again. Same reason she went to Windows XP's classic look.
What does Linux have to offer? Try WindowMaker's desktop - it's remarkably more efficient to multitask with, and it's so light that having 5-6 virtual desktops is easy, and completely not straining on the computer at all.
Try LyX as a document editor. No worrying about making things look right, or figuring out what point size looks correct, or making things work.
Or emacs as a text editor. My *word* you can type and edit at ridiculous speeds after spending maybe an hour going through the tutorial.
gnuplot for generating plots: hey, what do you know, you don't have to pay $1000 or more to actually get proper fits on graphs? Never would've known...
Yes, I know. I'm talking about Linux's apps rather than Linux, and I know that you can get them under Windows as well. But out of the box, any Linux distribution is far more user-friendly than a Windows install is.
I had to spend six hours today getting a damn network card working under Fedora. The same problem was resolved in XP with a mouse click and a textbox edit.
Oh, for crying out loud. Well, do you want me to tell you about the months that I've been waiting for a fix from Microsoft about that moronic DHCP problem? (To put it in more 'simple' terms: "My wireless card doesn't work anymore when I move it from work to home.")
Besides - if you knew how to set up the network card in Linux, it wouldn't've taken you six hours. It would've taken you two seconds. Forcing someone to learn something different does not make Linux innately less "user-friendly". It just makes it "not Windows." They had to learn Windows once, too.
For example, assembly language is a powerful tool. However, I think few people would describe it as "user-friendly", even though learning it has its benefits. In fact, it is decidedly not user-friendly: it is very easy to introduce many errors into your code and it is very hard to write good programs in assembly. So your definition fails miserably.
Easy can't be user-friendly either: an operating system that consists of a big giant button that says "Press any key to say hello" that says "Hello" when you push any key is amazingly easy. But no one would say it's "user-friendly". Can we continue with the strawmans?
User-friendly is a combination of ease and power that does not require an undue amount of stress for the user. Windows doesn't have that, not for a lot of applications.
It should also be noted that I'm a little jaded and generally lump the GNU tools into Linux, and lump only consider "Windows" to be Windows + the office apps - what most people consider to be the standard Linux distribution. The GNU tools are ridiculously more user-friendly than the Windows standard tools.
You appear to equate "make everything possible" with "user-friendly".
Nope. User-friendly is "make easy things easy, but make everything possible." At least, that's my best interpretation of it. And while Windows does make easy things easy, it fails horribly at making everything possible. So much so that people will literally look at you like you're a computer god when you say "yah, I can get the file that's on your computer halfway across the country. No problem."
That's one positive of Windows. It makes Linux users - even average ones - look brilliant.
Look, "easy" can't be "user-friendly". There was a TV commercial a while ago which had a businessperson constantly being harassed by salesmen who would solely say "Hi, would you like to buy software? How many copies? 1000? 2000? 3000?" If you wanted to buy software, that'd be tremendously easy! But no one would even suggest that it's user-friendly.:)
Obviously a geek, at least in this context, is somebody who spends a great deal of time working with computers because they *enjoy* working with computers.
No, that's a computer geek. While there may be a few people who enjoy *only* working with computers, I'm one of the people who just likes understanding things. Linux is for people who like understanding things. The problem with Windows is the fact that people who like understanding things, unless they know that Linux exists, just think that computers are magic. Windows makes people think that computers are complicated.
For my entire working adult life, I have built systems for people who do not like computers. They don't want to use them, they don't care how they work, and quite often they HATE them.
See, that, I blame on Windows. Windows is extremely limited in what it lets people do, and so people hate them, because they're ridiculously complicated. I even think GUIs are responsible for people hating computers as well - the command line is far more efficient, and it's far more understandable (run command, get result). The command line also eliminates the "three-column start page" problem - it allows you to have literally hundreds of programs without having to sift through tons of them to find it. The downside is, of course, that you have to know what program to use - but if you're a user trying to figure out what to do, you'd rather learn "oh, I did have that program" than "I have to download something."
(It should also be noted that cygwin tends to mediate Windows significantly for me. First thing I do when I have to work on a Windows box somewhere is install Cygwin...)
It is more friendly to a user who is knows what they're doing and is looking for control and configurability, but that isn't the definition of user-friendly.
No, that's the definition of powerful. User-friendly is best described as an ideal combination of ease and power, and I do not give that to Windows. I would almost entirely credit that to Linux due to emacs and LyX, at least for anyone who writes documents. Word is an awful word processor. Ugh.
I mean, after all, user-friendly depends significantly upon what someone plans on doing with a computer. I can literally only find maybe one use - maybe two - that Windows is more user-friendly than Linux: Games and maybe media playing, as mplayer is always a bloody hassle.
You are equating "easier to use" with "easier to customize"
And you're equating "easy" with "user-friendly", which aren't the same. "Make easy things easy, but make everything possible." That's my new mantra.
but worrying about wireless DHCP is hardly type kind of thing that typifies an ease-of-use discussion.
What?! Almost all laptops nowadays have a wireless connection in them. DHCP is standard for network environments.
In fact, it took forever to realize what was screwing up in Windows, which is the *other* problem. The point is that Windows makes it so you don't have to learn, and it actively discourages you from being able to learn! (How do you find out that the DHCP lookup failed? You don't. I go and try to open a web browser, and I sit and wait for several minutes while the damned thing times out). The first is "making things easy", and it's okay. The second is making things non-userfriendly, and that's not okay.
to accomodate those who aren't hardcore day-in/day-out geeks.
What is a "geek"? Someone who wants to learn? If you're suggesting that I would prefer that Linux doesn't change and continues to cater to people who want to learn and actively investigate things that they use to see what they can do and how they can be improved, you're very right that I don't.
What Debian strives to be is a universal, free, and open operating system. (Most Linux distributions do too, but I'll just say 'Debian' here because honestly, it flat out states that's what it wants) "Open" means that it's *possible* to learn everything you can about the operating system. No one would claim that that's possible for Windows.
Or even my father, who is now a bit old, but has used computers (strictly as a user) continuously since 1980.
With your father, it'd be easy. Computers since 1980? That's DOS era, and understanding the hell that DOS is means that you'd definitely appreciate automated program downloading.
apt-get's a breeze to explain. Ask them if they've ever installed software that said "you need to install Acrobat Reader" and then asked if they want to install Acrobat 3. This is moronic, and it can really screw up your system if you just do it. (A worse example is DirectX, which Microsoft only recently put in checks to make sure that old versions don't overwrite new ones).
Linux is usable. It is not easy to use.
Nothing that's easy is worth doing.:)
As for the almost irrelevant question of how long I've been here
You're the one who brought it up, not me. As for the acoustic-coupler teletype, c'mon. Yah, my first modem was an acoustic-coupled 300 baud, but I was something like 5, so give me a break.:)
Incidentally, it's nice to see a response other than "that's stupid." Considering that's the rough equivalent of a 3-year old's response, I didn't think a harsh reply was unwarranted.
She's using Windows XP. She immediately set it to the Classic theme.
Doesn't that almost exactly justify what I said before? The new theme is much more user-friendly, yet she didn't want to switch because it was more comfortable to use.
Most people justify this behavior by saying "well, I want to use this thing, I don't want spend all my time learning" but that's idiotic. It's a justification for being lazy.
A good analogy would be a person who learns to drive a car stick-shift, but doesn't learn how to shift out of first gear. His reasoning? "Well, I want to use this car, I don't want to spend all my time learning."
Meanwhile another person spends a few more minutes learning, and blows by the guy on the highway while he's doing 10 mph.
If you want to examine whether or not something is user friendly - well, that's more difficult. Studies really have shown that the learning curve for Linux is not much different than the learning curve for Windows, and the Windows users tend to plateau at a lower level because the limited options keep them there. "User friendly" is really a combination of "how much can I do with the operating system" and "how fast can I get there"?
If the things you expected (that you listed) weren't true, then something went really wrong. I heartily agree that those things should be true of all operating systems, and in every single Debian installation I have, that is true. Package and program management is the one thing that operating systems should do well.
But again, the "user friendly" nature of an operating system isn't whether or not something that should work does work. Every operating system is broken, in some way. The "user friendly" nature is "how easy is it to figure out the problem, and fix this?" and that's where any Linux installation shines, and that's also where I really prefer Debian because of the huge knowledgebase and extensive documentation.
don't play this stupid games, please.
It's not a stupid game. I use Debian, Red Hat, and Windows (don't ask, I own/use/administer so many machines it's frightening) - I'm not a "Debian user" - I'm a computer user, and I regularly switch operating systems when one of them works better for me. Dear God, I'd like to ditch Windows because if I try to multitask and do something else while I'm waiting for something to compile or run, it's always a disaster.
Do I think Debian runs "perfectly"? Hell no - see other posts regarding a libgphoto2 problem I had. But I filed a bug, and now someone else will know as well, and more importantly, it took me less time to fix that problem than it would on, for instance, Windows (which would be -months-). Red Hat would've been about the same time, as rpm's rebuild mechanisms are pretty good.
You got one point : I'm lazy. I have a limited time in one day, and I choose the system that works. (I know, "no system works blablabla", but I think we don't live on the same planet).
Sure, and with Red Hat, I don't blame you for sticking there, because really the only reason I push for Debian is that I don't have time to remember the way that each specific machine is set up, and I stopped pushing Red Hat before urpmi/up2date/etc. came around. I still prefer Debian because apt is much more mature and has a larger software base, but Fedora is getting there, just like Gentoo is.
Besides, there's no huge reason to switch away from Red Hat, not even from a user friendly point of view - Red Hat isn't *too* bad at hiding things from the user.
You love OSs which need days or weeks to learn how they work ? Fine. I personnaly don't like to spare my time in configuration problems. I want to **use** it, not to configure it. You understand the difference ?
There isn't one. If you use something without understanding it, you're asking for problems. It's amazing that "RTFM" is an acronym. It's absolutely incredible that people don't read documentation or search for documentation at all when they use something.
How long does it take to read? Nowhere near the amount of time it takes to muck around and try to fix a problem after you've botched it beyond belief.
Note that the problem I mainly have here is *Windows*, not Red Hat. Debian has a better support infrastructure (as its mainly straight Linux, not heavily modified) in my experience, but I think that the Red Hat community with Fedora is really starting to coalesce.
But Windows is an absolute crock when it comes to this stuff. How do you fix a problem where the system doesn't want to renew the DHCP lease? Can you find this documentation *anywhere* on Windows? (You could browse the Web, and learn about ipconfig/release and ipconfig/renew, but in some cases even *they* don't work). On Linux, man dhclient will do it. Reading the Debian User's Guide will even tell you how to restart networking if you need to.
Windows is not user-friendly. It's *easy*. There's a difference. Easy things are good when you're not trying to do anything complicated. Problem is that nothing that's easy is worth doing.
I bet most of those people probably wouldn't want to learn to drive a car with the steering wheel on the wrong side of the car. But you wouldn't consider it less 'user-friendly' would you?
That's a terrific analogy. I'm going to have to use that one more often. Another easy analogy would be stick vs. automatic: a real "user-friendly" car would have *both* stick and automatic transmission modes - neither stick nor automatic are really "user-friendly" since both of them force the user into acting only the way that their paradigm encourages.
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The fact is, the Hubble and JWST instruments are *complementary*
Complementary would mean they don't overlap. They do. Significantly. JWST is optimized for infrared, because it's a deep-field utterly huge telescope for looking at gigantically distant things, but it reaches all the way to green.
neither does any other telescope currently available
Look, Hubble isn't perfect for UV. They've been planning on doing science in the UV without Hubble for many years now. It's not worth spending the money on Hubble rather than spending it on a telescope specifically designed for UV that doesn't overlap with JWST.
Also, I have never heard NASA say that the Hubble is just old and worn out. They say it's too risky to go up for another servicing mission.
It's not too risky. They could do it if they wanted to. They'd simply have to recertify the shuttles specifically to do it, and what they're saying is that the excess cost to do that is not worth the limited science that Hubble would do in the remaining years it has left.
In other words, Hubble is too expensive to keep running. That makes it uneconomical now.
The main problem with the controversy is that there are emotions involved, and that makes for very bad decision-making. Any of the advocates for Hubble always push the emotional attachment to Hubble, rather than the simple by-the-numbers math.
The only space telescope on the drawing board is the James Webb scope, and it's an IR scope. There's nothing even in the planning stages for a replacement for Hubble.
You're wrong. The JWST will cover some of the optical, just not up through blue. Why?
Because the optical is boring. Scientifically, it's not interesting. Deep-field objects are redshifted, and so naturally a big telescope will concentrate on the longer wavelengths.
Besides, go look at some of the pictures that Spitzer has put out. They look gorgeous. They're fake color, sure, but who cares? In fact a lot of this stuff is redshifted, as I mentioned, so you're not even looking at it in "real" light anyway.
The JWST is a replacement telescope to Hubble. Some features of Hubble's - like the ability to see in the blue band - just isn't that important for science right now.
and it'll keep going happily for a long time to come yet.
This is, of course, naive. Hubble is a space telescope, and it's already pockmarked from space debris. It's just a matter of time until Hubble is damaged beyond repair.
It was never meant to last forever. Let it die.
but suggesting that it's the most user friendly interface is, again, just stupid.
What's the pinnacle of user-friendly design? Most people would hold up the unattainable "Star Trek computer" as the pinnacle - "Computer, do this." "Computer, do that", and it just works. If you expect a response to your command, the computer speaks it to you.
That's a vocal version of a command line.
Simply put, it's more intuitive. And, quite frankly, it's easier to learn young: I started learning how to use a computer when I was 4, but there's no way I could've used Windows now when I was 4 - the manual coordination wasn't there (and yes, I learned to read young).
I don't understand why command lines are given the bad rap they are. If you're trying to say that "grep Mike files | awk {'print $2 $3'} | sed s/form/from/" is too difficult to learn, I (might) agree with you. But a prompt where you just type
"find all files containing Mike, print second and third word, substitute from for form, print results." is not user-unfriendly. It's nearly perfect, in fact.
Much easier than "Click on Find. Click on 'Options'. Click on 'Output'." etc. etc.
The problem may be that the command line is too immature to be generically useful. True. But it is not a poor UI. Its main limitation - needing to know a vocabulary - is an implementation issue, because natural-language parsing isn't good yet. It's not a UI problem.
I'm glad you brought up the stick-shift, because I almost did last time. Guess what? In order to learn how to drive, I don't need to learn how to put a car into 2nd, or even 1st, with a stick shift. I can just put the big dumb circle over the big D and hit the gas! Wow! Not only do I not need to know all about gears, carberators, brake lines, etc., I don't even need to know how to drive a manual. The fact that it might be better is not the issue, it's what is easiest for 95% of the users.
Here's the interesting thing - only in the US is automatic transmission dominant. Pretty much everywhere else, manual dominates massively, and the reason is because manual transmission is simply better than automatic, and the learning curve is not that high. I doubt the people in those countries would claim that manual transmissions aren't "user-friendly". If the excess power justifies a learning curve, it's not "user-unfriendly".
I guess what I'm saying is that in my opinion, a user-friendly operating system needs to minimize the frustration of the user. With Windows (and Microsoft products), it just doesn't do that. If you're Bill Gates, it probably works fine, but for anyone who uses real products, it's a pain.
But anyway, the point is that your opinion of user-friendly is "make the common things easy", and that's not mine, because while it makes people happy when things work, the fact that you can't fix things, nor can you even figure them out, means that not only will ordinary users occasionally get frustrated, but power users will too!
Could you imagine if my brother and mom asked me "Hey, can you figure out why my wireless network card is acting weird?" and I just told them "Um. Well, Windows is broken. There isn't really a way to make it work." Remember, as far as they know, I'm the expert. This would be like a car mechanic saying that you're going to have to live with some weird "clunking" sound because there was no way to inspect the engine and figure it out!
To think that an average computer user is going to learn enough to script an auto DHCP release/renew is simply absurd.
I never said that. I said I could. If my mom needed me to, I could do it. You yourself said it - pay an expert to fix any problems. All the people who are whining about how hard it is to install a network card in Linux - why don't they just ask an expert?
Now would someone tell me how to make Windows' DHCP requesting work properly with wireless network shifts? Oh, wait! There's no way to do it! And, for more fun, I can't even pay a smarter expert to fix it, because they've already told me that they don't know, either! And Microsoft? 3 emails down, no responses yet!
Keep in mind, all I'm trying to do is make wireless networking work. If this was a common user, all they would know is that it doesn't work. Not that the DHCP release isn't working. In fact, before I knew about ipconfig, I had to physically remove the network card to get it to work. Now that I've got an integrated wireless card, I couldn't even do that. I have no idea what I'd do. Rebooting doesn't even work.
(And, for what it's worth, the DHCP release/renew daemon is already written in Linux - it's called ifplugd/waproamd, and it's heavily commented, and heavily documented.)
Let me put it this way: suppose someone can't get something to work under Linux. What do they do? Well, they could whine and complain, or they could post a message on one of many mailing lists or message boards saying "hey, this doesn't work. Anyone got any ideas?" Chances are they'd get information back very soon giving advice or, regretfully, telling them that they don't have much luck (although DriverLoader may hopefully make the driver issue moot - and yes, Windows driver emulation is a good thing in my opinion).
But what they would not be is left out in the cold, which is where they'd be if they were in Windows.
I'm
(frictional forces on the ribbon through atmosphere) and the entire system will eventually burn up in re-entry (loss of orbital momentum due to dragging 100k km of ribbon through atmosphere).
Wow, I didn't even notice this the first time through.
The elevator is stationary with respect to the atmosphere. Why would there be any friction on it from non-moving air?
Yum yum, get me some of this troll bait!
This is not a troll. This is pointing out that one of the main benefits of Linux over Windows is the fact that it's open. There's information out there about it. You can learn how to do almost anything, and the operating system encourages you to do it.
Windows doesn't - it forces you into the Microsoft mindset. Anything outside of that is very, very hard to get around. It's very "closed". And that's why I get very annoyed at people who insist that Linux needs to become more like Microsoft, and "hide" things.
His point is that anyone could have set it up under WinXP in two minutes.
Ha! My mother-in-law, mother, or brother couldn't've set it up in WinXP in two days. They don't know where to start.
Us telling them "Move the mouse to the Start menu, click the left mouse button, then up to where it now says 'Settings', then over to where it will then say 'Control Panel', then click the left mouse button." and us telling them "Press Ctrl, Alt, and F1 at the same time. Type your username and password. Type "etherconf", and follow my instructions" is just as easy - in fact, as you can see, it actually takes less instructions. (Actually, if you really need to set up TCP/IP settings in Windows, it can be quite complicated for someone who hasn't used a computer before, because a lot of the interface is crazy: when you enter an IP address, you have to be very careful, as it barks at you if you even try to enter in anything greater than 255. This is dumb - it should tell you this after you enter the entire thing in and try to apply it. It slows the process down, and it frustrates the user - especially one who needs to look at the keyboard to type - that is, someone new)
If you're talking about Windows XP's autodetecting new hardware, it should be noted that Mandrake and Red Hat both have autodetect/autoconfigure mechanisms as well. And Windows XP's behavior when it can't find a driver is often times insanely stupid, and it doesn't make anything "easier" to a user.
Frankly, I think you're misappropriating the term "user friendly".
Take two people who don't know anything about computers whatsoever. Give one a computer with Windows, and one a computer with Linux. Give them both access to customer support and help. Now wait a year, and see which user is more proficient and knowledgeable about their computer.
The OS with the more procifient user is more user-friendly, because it helped them be as productive as possible. Whether or not it was easy isn't the whole story. People use computers to be more productive, not just to use them. An OS that fights with its users because it thinks it knows best isn't user-friendly.
They've learned the Desktop/Folder paradigm.
And how is that user-friendly? It actually artificially introduces a lot of things which aren't true, like only the things that are on My Desktop are easily reachable. (Windows XP, by default, discourages access to the hard drive directly).
In fact, it's "user-harmful", as it presents a paradigm to people that the rest of the computer doesn't really follow.
It also discourages people from learning how to type, as almost all of the interaction is via the mouse, and the productivity using the mouse is far worse than using a keyboard.
Try realizing that you and (likely) the people you know are not average.
I don't have that much of an ego.
There are very few people I know who wouldn't be able to learn what I know in just a few months of learning. The point that I'm trying to make is that Windows discourages people from learning how a computer actually works - it hides tons of things for no good reason. This isn't "user-friendly" behavior. There's no good documentation for almost everything - there's more bad documentation than good. "Clicking the 'Close Window' button closes the window." Yah, that's useful documentation.
This statement is completely opposite to the laws of thermodynamics.
:) )
No, it isn't. The best description of the laws of thermodynamics that I've heard is (yes, I know what the actual wording is, but I think this better describes the effects
1: You can't win.
2: You can't even break even.
3: You can't get out of the game.
None of these say "you can't play really, really bad." It just limits how good you could possibly play, if the Universe was fair and everything was perfect. Remember that no one can actually build a practical Carnot engine - we're forced to use the far less efficient Otto cycle, and people dream of using the Stirling cycle, which is better, but still not Carnot.
The hotter your heatsource is, the more efficient you can do work with it.
Not really. The hotter your heat source is, the more the maximum efficiency you could ever reach gets. That doesn't mean you practically can do more work with it.
The best example would be neutrinos: a neutron star gives off a tremendous amount of neutrinos when it's first born via the URCA process (neutron->neutron + electron neutrino + electron antineutrino, via inverse beta decay+beta decay) - more energy than the Sun gives off in its entire lifetime. But it's nearly impossible to convert any of that energy into work, because neutrinos barely interact at all. The volume of the "block" that heats up would probably have to be the volume of the entire solar system, and therefore it would barely heat up at all because of the huge heat capacity, and (by the second law of thermodynamics), your efficiency of conversion is terrible.
Similar things happen here: many forms of radiation are very hard to absorb, and therefore there's no practical way to convert back into useful work. Sure, you could try to absorb the radiation and heat something up that way - but the conversion efficiency would be terrible, since most of the betas and gammas would zip right through your absorber, and only deposit a small fraction of their energy, which means the engine you finally build will have even worse efficiency.
The big problem is to get some energy out of heat with a lower quality
Huh? Heat is heat is heat is heat - it's kinetic energy of particles moving around, and it's all of the same "quality". It's not sunlight. Sunlight is light, and conversion efficiencies of sunlight -> work are actually not bad. Hence the whole solar power thing.
The cable is attached to a weight that rests on the earths surface, (or on the ocean). This weight weighs much more than any climber that is to go up the ribbon, in fact it weighs more than the cable can support, so if it was over a hole the ribbon would fall to earth, however because the earth's surface will support any weight that the ribbon does not the system is in equilibrium.
What the heck are you talking about? The cable is in orbit - it's not "resting" on the Earth's surface at all. When a climber's not on the cable, the cable just hangs there. It wouldn't have to be tethered to anything at all. (Why would it? It's in orbit - satellites in geosynchronous orbit aren't tethered to anything, and they just hang there, and that's all that a space elevator is!)
When a climber pulls on the cable, the part below the cable slacks slightly because the cable starts "pulling" to the east, because its center of mass is now too low, and the orbit is faster than geosynchronous (i.e. toward the earth and westward. This is where the climber gets its angular momentum from, because it's slowing the Earth's rotation down. The slack in the cable is determined by the Young's modulus of the ribbon - i.e., how much the cable "stretches" under load.
If the cable were to break at the base, the cable would start drifting eastward, very slowly. With the climber on, the ribbon is too heavy - it doesn't head outward, it heads inward. It doesn't fall, of course, because it's in orbit - it just starts dragging around the globe in an elliptical orbit, very slowly. When the climber lets go, the ribbon slowly moves upwards back into a geosynchronous orbit, and from the Earth's frame, it stops moving. It might actually start moving around a little bit due to odd extra components.
If there was no tension in the cable it would be impossible to attach a climber.
There is tension in the cable without it being tied to the ground! Tension due to gravity - several thousand tons of tension!
only force the climber could act against would be the inertia of the system, and that means accelerating it towards the ground.
By your argument, any satellite could never stay in orbit. It is constantly accelerated towards the ground, but it's also got a tangential velocity sufficient to keep it in orbit.
Look, this is simple orbital mechanics. Ignore the fact that the ribbon's an extended object - just concentrate on the movement of the center of gravity, which is at geosynchronous orbit. When you add a climber, the c.g. moves down, so the orbit speeds up. When the climber lets go, the c.g. moves up, so the orbit slows down.
That is why you would first need to increase the mass of Mars, that is, create a new planet by tossing a few spares together. Mars, Venus, maybe some of Jupiters moons (Europa could be the iceing on the cake). Just got to make sure the pieces stay together and wait for it to become stable. It would clean up this star system some to boot.
Mars slamming into Venus would probably generate an Earth-Moon system pretty similar to what we have now - the Earth would be a little larger, the Moon would be a little bigger, but it'd be about right.
Venus is 90% mass of Earth, Moon is about 1%, and Mars is about 30%. They'd be all you need.
It would also generate a magnetic field on Venus, very likely, as Venus's problem is that it doesn't spin fast enough. The collision would also strip large portions of the dense atmosphere away, and with the rapid spinning, a thermal equilibrium would probably quickly form.
Venus's lack of rotation is probably the only real significant inhibitor to terraforming it.
However, I think it's a waste of resources using mass as a source of gravity
Why? Mass is the most efficient way of storing energy in the known Universe, and you need energy to generate gravity. Seems to me that mass is pretty ideal.
Dangit! Water expands when it FREEZES. Arrgh!
That's where the research is.
No, it isn't. This is where the research was 50 years ago when people were still trying to understand the EPR experiment. It's pretty much understood now.
If we can influence the level/wavelength/quantum parameters (e.g. spin) of a particle, we can *instantaneously* influence the energy of a particle some distance away.
That's the problem. You can't influence the determination of the outcome of the first experiment - the first determination of the spin. It's random. By definition. Random. And that's because it was determined by a random process. There is no way you could influence it, any more than an observer can influence a shadow. It was generated by a process that, if you could influence it, would eliminate any benefit of influence.
Interestingly, a lot of research is also being done into non-intrusive measurement, a method by which they can measure the state of an object without affecting it too much.
You're not understanding what they're doing. There is no way to measure certain things - like the Z-dir spin of a particle - without affecting it. That's because the Z-dir spin of a particle is determined by interactions, so interacting with it is (obviously) going to change it! There are ways to determine certain things about a state without affecting others, but that's because those variables aren't complementary.
Also, you might want to look at the results of the quantum teleportation experiments from a year or so ago, where they did indeed 'force object B's measurement to have a desired result' by superimposing a quantum wavestate of an existing photon over a new photon, effectively teleporting the photon.
That is not what happened there. What happened there was that they "teleported" the original photon by recreating its state later. You cannot do the same thing with an entangled photon. Can't. Not "can't because of some pre-established rules". Can't because it's already been proven that you can't.
Personally, I favor the latter. Specifically, if you look at some aspects of multidimensional theory, then it's feasible that the entangled particles are not violating the speed of light (provided you assume more than three dimensions, a la superstring theory.)
They're not violating the speed of light in normal quantum field theory - the Z-dir of spin is not something that's intrinsic to the particle, but conserved within interactions. It's a quantum shadow, nothing more, cast by interactions on a particle with spin.
Imagine someone with a normal flashlight, that spreads out as it gets farther. Now imagine that same flashlight seen on the Moon. Let's say, for the sake of argument, that it encompasses the full Moon's area. Now imagine someone moving their finger across that flashlight, and picture what that shadow does moving across the surface of the Moon. It moves across the Moon's area in a fraction of a second, which could be many times more than the speed of light on the surface. This isn't amazing, or surprising at all - there is nothing physical about that shadow at all. It can't convey information from one point on the moon to another, only from Earth to the Moon, which it does at the speed of light.
For a better description, with the proper math, of what I'm saying here, check Griffith's appendix on the EPR Paradox and Bell's theorem in "Introduction to Quantum Mechanics."
Yes, I believe the "hidden variables" approach to QM is correct -- it's not such a stretch for me to believe that all of the properties of a particle are set at definite values at any given instant. It's just that proving it (and it does require proof) is as difficult as proving that particles actually physically influence each other instantaneously over distances. But, the hidden variables approach doesn't violate causality and makes sense and until proven otherwise it seems to be the easier to believe.
Er? It was proven otherwise - by Bell's theorem. Hidden variables simply produces a different answer than QM - a *wrong* answer, based on experiment. The only assumption was that the variables are local. If you go to a global hidden variable theory, you'll violate causality.
The problem with what both of you are discussing is the fact that you're assuming that, for instance, the z-orientation of the "spin" of a particle is a "real" thing, something that every particle "must" have. This is the part that doesn't have to be true. The z-orientation of the spin of a particle is determined only by its relation to other particles, which is determined only by interactions. Those interactions need to conserve the quantities we observe (since they're *based* off of the symmetries that generate those conserved quantities) and so, you get "entanglement" to preserve those quantities. It's just a mathematical artifact to say that they "instantaneously influenced each other" - wavefunctions aren't directly measurable, because they're just math. The only thing that's "real" about a particle are its mass, spin, charge, and color (as in quantum color). Everything else - position, velocity, etc. - are all generated by interactions.
"FTL effects" are nothing new - I don't know why people think they are. ("Quantum" makes people go "ooh" apparently - though how quantum field theory could violate something it's based on, and still be consistent, should make people's eyebrows raise) An amazing, complicated effect known as a shadow can exhibit "superluminal effects" - just imagine someone shining a flashlight at the moon, and moving their finger across it rapidly. The shadow cast by their finger will travel much faster than the speed of light at the Moon, because the distance covered is huge. But a shadow can't convey information from one point of the Moon to another, because they'd have to go through Earth first.
When the ribbon is cut in such a situation, the SE will go into an elliptical orbit.
Yes, but that's basically an academic scenario, because it will only *start* to go into an elliptical orbit. In any real-life scenario, the climber would immediately be commanded to let go (explosive bolts!). It should be noted we're also considering the elevator's CM as a point mass, which it isn't - cutting the ribbon, while loaded, would likely do very odd things, but it's unlikely that it would be unrecoverable things. It may make the ribbon oscillate wildly for a while, which could be very dangerous, but it would settle down within the course of a few days. The bottom portion of the cable would "sproing", and bounce, a few hundred km, probably, but the energy would dissipate rapidly. The elevator operators would definitely spool out significant amounts of cable to alleviate those issues.
So, I guess, to amend the above, if the ribbon is unloaded (if the lifted mass is located near GEO) then cutting the ribbon at the anchor will do absolutely nothing. If the ribbon is loaded (the lifted mass is located near Earth) then cutting the ribbon at the anchor will cause problems, but not unrecoverable ones.
But what is it exactly about water that makes it so important?
Actually, that web site you linked to shows a lot of properties that are generic to all liquids - the unique one being that water expands when it contracts.
However, the question should be "why only water?" and the basic answer to that is pretty simple.
Life, simply put, could be described as nature selecting out certain configurations from a system that contains an almost infinite amount of states. Therefore, you need something that allows for many states and many configurations to form - that is, you want a dipole - subatomic "glue", basically - something that can take ions and join them together in weird ways to get bizarre states. Dipoles also act simultaneously as solvents - that is, they break down objects into dissolved ions.
Well, if you want a dipole for life, then you're probably going to get life based on the simplest dipole available. So you start with hydrogen, the most common element. And the simplest dipole you can form with hydrogen is water.
This, of course, doesn't preclude other elements from being the basic dipole for life if the region isn't compatible with water - though, unlike what the article says, Earth is not at the triple point of water - the blackbody temperature of Earth is ~255K, which is far underneath the freezing point of water (granted, triple points require knowledge of pressure, which eliminates a simple blackbody approach, but...). Earth's atmosphere, however, is at the triple point of water, but that's because it's been tuned to get to that point by the various thermal cycles and biological cycles which keep Earth's temperature near that point. What you really needed was liquid water, because as a solid or as a gas, the dipole properties are really being wasted. So, one can imagine a world where something just slightly more complicated than water (say... ammonia) is liquid, and maybe, just maybe, you'd get a complex chemistry out of that, too.
No tension eh?
So the cable stays taught because it has hairspray on it?
Sigh. I actually thought you might have read something about the space elevator concept.
The cable stays taut because of gravity. There is no tension between the cable and the ground. There is, in fact, no reason that the cable needs to touch the ground at all.
The cable remains taut because the center of mass is in geosync, and the inner cable needs to keep up with it - tension.
Imagine a spacecraft at geosynchronous orbit which extends 1 meter of cable downward, and 1 meter of cable upward. It, of course, stays at geosynch, because its center of mass is still at geosynch. Now have the spacecraft repeat that thousands of times, until the cable reaches near the Earth's surface. That's a space elevator. Don't think of it as interacting with the ground in any way. It isn't.
Cut it at the bottom, and it goes in orbit.
I'm sorry, but you're wrong. The cable already is in orbit . Cutting it at the bottom will simply move its center of mass infinitesimally higher, and will simply make it drift to the west very very slowly. Obviously it won't come back to the same place 24 hours later, so that part of the post was completely wrong. But cutting it at the bottom won't do anything. The cable will likely just sit there.
Ballparking some numbers: if you cut off the bottom 1 km of a 100,000 km cable, that will move the center-of-mass out about 0.001%. The cable's orbit was at a 24 hour orbit, and orbital periods go as proportional to the 3/2s power of the radius, so the period will increase about 0.001% (this is *really* ballparking). This means that the period increases by about one second per revolution. Something at the Earth's surface moves about half a kilometer a second while rotating (40K kilometers in ~ 80K seconds), so this means it moves about half a kilometer per day to the west. This means that it moves about 5 millimeters per second to the west.
Considering all they need to do is spool out 1km more cable downward, I think they might be able to recover it.
Though the orbit is geosynch, it isn't because of the distance of the center of mass of the thing. It's the distance of the center of mass of the thing while tied to the ground.
Um. No. The elevator most definitely wouldn't be "tied to the ground" in any significant way. It would be in orbit . Just like the ISS. Or the Shuttle. It just happens to be really really elongated as well, and one of its ends is near the surface of the Earth.
Cut the ribbon near the ground, and nothing happens . There's no tension against the ground - the tension is from gravity, along the object's length. Odd, and difficult to think about, yes, but absolutely one hundred percent classical physics.
Now, to correct myself - it would, of course, be tethered to the Earth. However, that would be for the sole purpose of damping out the natural 7 hour oscillation that comes from torquing a 100,000 km cable. And, of course, for compensating for an imperfect geosynch orbit, or a non-fixed anchor position (like a floating platform).
But then on my notebook I have to recompile my display drivers every fourth of fifth update, and I still haven't figured out why or when... heck, if I weren't a reasonably experienced user I probably never would've gotten the drivers going in the first place.
Pin the xserver-xfree86 release. Instructions on how are in the Debian User's Guide. That way it won't get upgraded, but everything else will. It should be noted that notebook video is *terribly* supported, but there are *plenty* of guides out there as to how to do it - tuxmobil has them.
(You also then should do the trick above which emails you changes specifically for the xserver-xfree86 release coming from the security dist.)
And as related to previous discussions, the reason that apt's better than Windows Update is that it allows you to customize in this way. With Microsoft, it's "You want to install these updates. Really you do. Trust in Microsoft. Believe Microsoft. Microsoft is good. Watch the spinning lights."
Seriously, why should she have switched? Linux has to offer something BETTER and DIFFERENT from Windows, not rip them off in the next KDE version.
There's the problem. She's just looking for Windows, again. Same reason she went to Windows XP's classic look.
What does Linux have to offer? Try WindowMaker's desktop - it's remarkably more efficient to multitask with, and it's so light that having 5-6 virtual desktops is easy, and completely not straining on the computer at all.
Try LyX as a document editor. No worrying about making things look right, or figuring out what point size looks correct, or making things work.
Or emacs as a text editor. My *word* you can type and edit at ridiculous speeds after spending maybe an hour going through the tutorial.
gnuplot for generating plots: hey, what do you know, you don't have to pay $1000 or more to actually get proper fits on graphs? Never would've known...
Yes, I know. I'm talking about Linux's apps rather than Linux, and I know that you can get them under Windows as well. But out of the box, any Linux distribution is far more user-friendly than a Windows install is.
I had to spend six hours today getting a damn network card working under Fedora. The same problem was resolved in XP with a mouse click and a textbox edit.
Oh, for crying out loud. Well, do you want me to tell you about the months that I've been waiting for a fix from Microsoft about that moronic DHCP problem? (To put it in more 'simple' terms: "My wireless card doesn't work anymore when I move it from work to home.")
Besides - if you knew how to set up the network card in Linux, it wouldn't've taken you six hours. It would've taken you two seconds. Forcing someone to learn something different does not make Linux innately less "user-friendly". It just makes it "not Windows." They had to learn Windows once, too.
For example, assembly language is a powerful tool. However, I think few people would describe it as "user-friendly", even though learning it has its benefits. In fact, it is decidedly not user-friendly: it is very easy to introduce many errors into your code and it is very hard to write good programs in assembly. So your definition fails miserably.
Easy can't be user-friendly either: an operating system that consists of a big giant button that says "Press any key to say hello" that says "Hello" when you push any key is amazingly easy. But no one would say it's "user-friendly". Can we continue with the strawmans?
User-friendly is a combination of ease and power that does not require an undue amount of stress for the user. Windows doesn't have that, not for a lot of applications.
It should also be noted that I'm a little jaded and generally lump the GNU tools into Linux, and lump only consider "Windows" to be Windows + the office apps - what most people consider to be the standard Linux distribution. The GNU tools are ridiculously more user-friendly than the Windows standard tools.
You appear to equate "make everything possible" with "user-friendly".
Nope. User-friendly is "make easy things easy, but make everything possible." At least, that's my best interpretation of it. And while Windows does make easy things easy, it fails horribly at making everything possible. So much so that people will literally look at you like you're a computer god when you say "yah, I can get the file that's on your computer halfway across the country. No problem."
That's one positive of Windows. It makes Linux users - even average ones - look brilliant.
Look, "easy" can't be "user-friendly". There was a TV commercial a while ago which had a businessperson constantly being harassed by salesmen who would solely say "Hi, would you like to buy software? How many copies? 1000? 2000? 3000?" If you wanted to buy software, that'd be tremendously easy! But no one would even suggest that it's user-friendly.
Obviously a geek, at least in this context, is somebody who spends a great deal of time working with computers because they *enjoy* working with computers.
No, that's a computer geek. While there may be a few people who enjoy *only* working with computers, I'm one of the people who just likes understanding things. Linux is for people who like understanding things. The problem with Windows is the fact that people who like understanding things, unless they know that Linux exists, just think that computers are magic. Windows makes people think that computers are complicated.
For my entire working adult life, I have built systems for people who do not like computers. They don't want to use them, they don't care how they work, and quite often they HATE them.
See, that, I blame on Windows. Windows is extremely limited in what it lets people do, and so people hate them, because they're ridiculously complicated. I even think GUIs are responsible for people hating computers as well - the command line is far more efficient, and it's far more understandable (run command, get result). The command line also eliminates the "three-column start page" problem - it allows you to have literally hundreds of programs without having to sift through tons of them to find it. The downside is, of course, that you have to know what program to use - but if you're a user trying to figure out what to do, you'd rather learn "oh, I did have that program" than "I have to download something."
(It should also be noted that cygwin tends to mediate Windows significantly for me. First thing I do when I have to work on a Windows box somewhere is install Cygwin...)
It is more friendly to a user who is knows what they're doing and is looking for control and configurability, but that isn't the definition of user-friendly.
No, that's the definition of powerful. User-friendly is best described as an ideal combination of ease and power, and I do not give that to Windows. I would almost entirely credit that to Linux due to emacs and LyX, at least for anyone who writes documents. Word is an awful word processor. Ugh.
I mean, after all, user-friendly depends significantly upon what someone plans on doing with a computer. I can literally only find maybe one use - maybe two - that Windows is more user-friendly than Linux: Games and maybe media playing, as mplayer is always a bloody hassle.
You are equating "easier to use" with "easier to customize"
:)
:)
And you're equating "easy" with "user-friendly", which aren't the same. "Make easy things easy, but make everything possible." That's my new mantra.
but worrying about wireless DHCP is hardly type kind of thing that typifies an ease-of-use discussion.
What?! Almost all laptops nowadays have a wireless connection in them. DHCP is standard for network environments.
In fact, it took forever to realize what was screwing up in Windows, which is the *other* problem. The point is that Windows makes it so you don't have to learn, and it actively discourages you from being able to learn! (How do you find out that the DHCP lookup failed? You don't. I go and try to open a web browser, and I sit and wait for several minutes while the damned thing times out). The first is "making things easy", and it's okay. The second is making things non-userfriendly, and that's not okay.
to accomodate those who aren't hardcore day-in/day-out geeks.
What is a "geek"? Someone who wants to learn? If you're suggesting that I would prefer that Linux doesn't change and continues to cater to people who want to learn and actively investigate things that they use to see what they can do and how they can be improved, you're very right that I don't.
What Debian strives to be is a universal, free, and open operating system. (Most Linux distributions do too, but I'll just say 'Debian' here because honestly, it flat out states that's what it wants) "Open" means that it's *possible* to learn everything you can about the operating system. No one would claim that that's possible for Windows.
Or even my father, who is now a bit old, but has used computers (strictly as a user) continuously since 1980.
With your father, it'd be easy. Computers since 1980? That's DOS era, and understanding the hell that DOS is means that you'd definitely appreciate automated program downloading.
apt-get's a breeze to explain. Ask them if they've ever installed software that said "you need to install Acrobat Reader" and then asked if they want to install Acrobat 3. This is moronic, and it can really screw up your system if you just do it. (A worse example is DirectX, which Microsoft only recently put in checks to make sure that old versions don't overwrite new ones).
Linux is usable. It is not easy to use.
Nothing that's easy is worth doing.
As for the almost irrelevant question of how long I've been here
You're the one who brought it up, not me. As for the acoustic-coupler teletype, c'mon. Yah, my first modem was an acoustic-coupled 300 baud, but I was something like 5, so give me a break.
Incidentally, it's nice to see a response other than "that's stupid." Considering that's the rough equivalent of a 3-year old's response, I didn't think a harsh reply was unwarranted.
She's using Windows XP. She immediately set it to the Classic theme.
Doesn't that almost exactly justify what I said before? The new theme is much more user-friendly, yet she didn't want to switch because it was more comfortable to use.
Most people justify this behavior by saying "well, I want to use this thing, I don't want spend all my time learning" but that's idiotic. It's a justification for being lazy.
A good analogy would be a person who learns to drive a car stick-shift, but doesn't learn how to shift out of first gear. His reasoning? "Well, I want to use this car, I don't want to spend all my time learning."
Meanwhile another person spends a few more minutes learning, and blows by the guy on the highway while he's doing 10 mph.
If you want to examine whether or not something is user friendly - well, that's more difficult. Studies really have shown that the learning curve for Linux is not much different than the learning curve for Windows, and the Windows users tend to plateau at a lower level because the limited options keep them there. "User friendly" is really a combination of "how much can I do with the operating system" and "how fast can I get there"?
I *expect* something from an operating system.
/release and ipconfig /renew, but in some cases even *they* don't work). On Linux, man dhclient will do it. Reading the Debian User's Guide will even tell you how to restart networking if you need to.
If the things you expected (that you listed) weren't true, then something went really wrong. I heartily agree that those things should be true of all operating systems, and in every single Debian installation I have, that is true. Package and program management is the one thing that operating systems should do well.
But again, the "user friendly" nature of an operating system isn't whether or not something that should work does work. Every operating system is broken, in some way. The "user friendly" nature is "how easy is it to figure out the problem, and fix this?" and that's where any Linux installation shines, and that's also where I really prefer Debian because of the huge knowledgebase and extensive documentation.
don't play this stupid games, please.
It's not a stupid game. I use Debian, Red Hat, and Windows (don't ask, I own/use/administer so many machines it's frightening) - I'm not a "Debian user" - I'm a computer user, and I regularly switch operating systems when one of them works better for me. Dear God, I'd like to ditch Windows because if I try to multitask and do something else while I'm waiting for something to compile or run, it's always a disaster.
Do I think Debian runs "perfectly"? Hell no - see other posts regarding a libgphoto2 problem I had. But I filed a bug, and now someone else will know as well, and more importantly, it took me less time to fix that problem than it would on, for instance, Windows (which would be -months-). Red Hat would've been about the same time, as rpm's rebuild mechanisms are pretty good.
You got one point : I'm lazy. I have a limited time in one day, and I choose the system that works. (I know, "no system works blablabla", but I think we don't live on the same planet).
Sure, and with Red Hat, I don't blame you for sticking there, because really the only reason I push for Debian is that I don't have time to remember the way that each specific machine is set up, and I stopped pushing Red Hat before urpmi/up2date/etc. came around. I still prefer Debian because apt is much more mature and has a larger software base, but Fedora is getting there, just like Gentoo is.
Besides, there's no huge reason to switch away from Red Hat, not even from a user friendly point of view - Red Hat isn't *too* bad at hiding things from the user.
You love OSs which need days or weeks to learn how they work ? Fine. I personnaly don't like to spare my time in configuration problems. I want to **use** it, not to configure it. You understand the difference ?
There isn't one. If you use something without understanding it, you're asking for problems. It's amazing that "RTFM" is an acronym. It's absolutely incredible that people don't read documentation or search for documentation at all when they use something.
How long does it take to read? Nowhere near the amount of time it takes to muck around and try to fix a problem after you've botched it beyond belief.
Note that the problem I mainly have here is *Windows*, not Red Hat. Debian has a better support infrastructure (as its mainly straight Linux, not heavily modified) in my experience, but I think that the Red Hat community with Fedora is really starting to coalesce.
But Windows is an absolute crock when it comes to this stuff. How do you fix a problem where the system doesn't want to renew the DHCP lease? Can you find this documentation *anywhere* on Windows? (You could browse the Web, and learn about ipconfig
Windows is not user-friendly. It's *easy*. There's a difference. Easy things are good when you're not trying to do anything complicated. Problem is that nothing that's easy is worth doing.
Mac OS X r
I bet most of those people probably wouldn't want to learn to drive a car with the steering wheel on the wrong side of the car. But you wouldn't consider it less 'user-friendly' would you?
That's a terrific analogy. I'm going to have to use that one more often. Another easy analogy would be stick vs. automatic: a real "user-friendly" car would have *both* stick and automatic transmission modes - neither stick nor automatic are really "user-friendly" since both of them force the user into acting only the way that their paradigm encourages.