Correct, all air traffic globally is regulated by international law, and in the USA the airspace is administered by the FAA. Unless you go to a huge hassle to get an airworthiness certificate and licenses (a big hassle, and probably impractical unless you are a professional or seriously hardcore enthusiast), you MUST comply with the existing exceptions for radio controlled craft. This means:
Line of sight. You must stay within line of sight of the aircraft, and you also must be able to take control of the aircraft in an emergency.
Altitude restriction, no higher than 400ft. You also need to keep clear of (and give way to) full-scale aircraft (presumably you would never be flying anywhere near a regular airport, but you still may encounter paragliders, sail planes etc).
Keep clear of built up areas. So definitely no barrel roll under a bus!
Finally, it sounds like the submitter is completely new to the field, in which case the place to start is to buy yourself a cheap R/C kit and learn how to fly it. You need to be able to fly R/C anyway so this is surely the best entry into the field. Building your own airframe is possible, but seriously hard: you certainly don't want to do it for your first airframe anyway, because you are almost certainly going to crash it, lots, while learning how to fly R/C, and you want something that will fly well immediately, without extensive tuning. And then, once you start debugging the autopilot, you will probably crash it lots more. Start from a cheap kit, and take it from there.
I think you (and a lot of posters here) are missing a basic point. Which is that you can have your own kids, observe them as much as you like or whatever, but unless you do a very careful and controlled experiment, you cannot distinguish what you think they are doing versus what is actually going on in their brain.
That is the difference that distinguishes science from superstition. The whole history of science is chock full of examples where reality turns out to be different from intuition. Even if your intuition is actually correct in this case, simply knowing for sure that your intuition is correct is useful knowledge. And without a doubt, there are some details about the functioning of your child's brain where your intuition is completely wrong. The process of science is figuring out exactly what that is.
I expect most of the carbon in a whale ends up in gaseous form, when the flesh decomposes. Some of it would dissolve in the water, but that too is a problem - increasing carbon dioxide concent in sea water is making it more acidic. And there is a saturation point at which there is so much dissolved carbon dioxide in the water that it won't absorb anymore, in which case any emitted gas goes straight into the atmosphere.
Yes, if there was an act of parliament associated with that (I don't know whether there was or not, but I would assume so). Actually this was one I was thinking about, since in the UK there was a real question as to the legality of the war. In the USA, that was never raised as a serious objection, but in the UK they went to great lengths to get a sham legal opinion justifying the legality of the war.
However, I am not sure whether the queen is allowed to get her own legal advice on legislation, prior to signing it. I suspect not, at least as far as I know it has never been done before.
Of course she rubber stamps everything - that is her job. But consider that her function is similar to the president in the old Weimar republic, but whereas the Weimar republic president was an explicitly political position with real power, and subject to influence (specifically, Hindenburg ended up playing into the hands of Hitler), the Monarchy in the UK is, in theory, above all that. Indeed, the Queen is not supposed to even comment publically on politics, although she certainly has a lot of influence, and has weekly meetings with the prime minister. But there is a last resort measure there, to refuse to sign a piece of legislation. It is unlikely to ever happen, and it would probably end up as the last thing the monarchy ever does, but nevertheless the safety net exists. Of course, that is only effective against some big 'Enabling Act' type of legislation, it does nothing against a gradual erosion of civil liberties, which is of course the problem today.
I am not a monarchist, and I'm not saying that it is a system that should be adopted anywhere that doesn't have a historical backing for it, but as far as systems of government go, a constitutional monarchy isn't bad. Compared with the USA, where if the president runs amok there is not much that can be done except impeachment (which is difficult, especially if the congress is controlled by the same political party as the president), it might even have some advantages.
In the UK there is a final arbiter; and that is the Queen, who must sign off on legislation before it becomes law. Nowdays it is mostly ceremonial, I don't think she has exercised the right to not sign legislation for a long time now (if ever, for the current monarch). But it does mean that there is an additional opportunity to stop any Enabling Act type legislation before it becomes law.
In principle, the constitution in the US is a strong document, but in the end it is people who have to uphold it. Primarily, the Justice Department is responsible for giving legal advice to the executive (and, I guess, to congress too?), and if they routinely give advice to the executive that is borderline or illegal, then there is not much recourse. The courts can usually intervene, but that is a slow process - and of course that depends on the courts finding out about the illegal activities in the first place.
But it is true though. Wine on Linux is probably far more backwards compatible for older Windows applications, than new versions of the Windows OS are.
In MS's battles to keep backwards compatibility, something went horribly wrong.
Did the GP actually make a mistake though? P is a subset of NP, but the GP referred to NP _complete_, which is an equivalence class and is not, in any sense, a superset of P (unless P=NP).
I don't get it: my main point was to refute the comment "Astronomers were well aware that the region of sky used for the Hubble deep field was full of distant objects.". You, at least, seem to agree with me that that statement is a bunk, since you allow for the possibility that they see 'nothing' but claim that would sill be interesting (well, maybe, but I doubt it would have been nearly as interesting as what they did see). What, exactly, are you trying to argue?
Astronomers were well aware that the region of sky used for the Hubble deep field was full of distant objects.
Wow, what a bunch of historical revisionism. How, exactly, were astronomers supposed to be 'well aware' that that pointing Hubble at a patch of sky where all previous surveys had shown nothing at all, would produce such interesting results?
What actually happened was that the director of the observatory has some 'discretionary' observing time on the telescope, that he/she is completely free to do what they want with, without the usual procedure of submitting an application for approval (a process that is quite competitive). Most likely, a normal application to observe in the deep field would have been rejected, on the grounds that there is insufficient justification and it could easily have ended up as a waste of time. Imagine submitting an application saying "we propose to point this multi-billion dollar instrument at a region of sky that is completely black and as far as we know, contains nothing" ? But Robert Williams, the then-director, decided to devote a large proportion of his discretionary time in 1995 to deep field imaging. The rest is history. And pretty pictures.
Well, since he has survived as director of a DOE lab for over 4 years, and is still managing to keep his sanity, I give him at least a 50% chance of surviving Washington. (As part of his job as director of LBL, he would have probably weekly meetings in Washington for the past 4+ years too, so he is not inexperienced as an administrator and dealing with politicians).
Fair enough, but you need to keep in mind that the problems you describe with medical insurance companies are almost exclusively a US problem. The US medical system is quite unique.
There is reason to believe that there were other buildings targeted in other cities, including the Seattle Space Needle and downtown Los Angeles. Supposedly, the other Al-Queida teams forgot to account for differences between time zones from one end of the USA to the next and the west coast groups never got into the air, or at least never were able to take over the cockpits like what happened on the east coast.
Really? If there was another team active in LA, then why didn't we hear about the arrests?
That is the whole point, the original election promise didn't make sense on lots of levels. But one level where it didn't make sense was to spend a lot of money to install filters for a set of known illegal URL's, and then let people opt-out of the filter. That would be like the police shutting down a brothel by posting a guard at the front door stopping people from entering, while putting up a sign to point out that people are still free to get in through the side entrance.
As soon as it became a tool for blocking illegal sites it was clear it would no longer be optional. If you are going to block illegal stuff, the it makes no sense to let people opt out of it.
Conroy is known as quite a back-room numbers man and power broker, but he isn't very well liked either. There are rumors that he's been set up to take the fall when the filtering scheme fails, along with the almost inevitable failure of the national broadband infrastructure tender process.
Rudd's interest in this is that both the filtering and the national broadband scheme were election promises, and while I admire his integrity in trying to carry through with all of his election promises (unlike the previous mob, who turned election lying into a high art), I really wish he would dump the promises that were clearly stupid. (I see now he has dumped the dumb idea of forming a Department of Homeland Security. That was surely an ill-advised scheme to attract right-wingnuts to vote for the Labor party.)
But the bottom line is that there is a real possibility that Rudd is complicit in setting Conroy up for the fall: he not only gets Conroy out of the front bench (and possibly out of parliament), but he also gets to dump the election promise of internet filtering with the excuse that it isn't his fault that Conroy botched it.
Ok, but it invites you to mislead. It would be quite possible to design it in a way that encourages good practice. I mean, Microsoft are already masters at inane dialog boxes. If clippy popped up and asked "are you sure you want to chop off the axes of this plot?", or "are you sure that your bullet points accurately represent the data?" it would make statisticians very happy (as well as pissed off at the interference:-)
Tools can be designed with a focus on best practice, or they can be designed to appeal to the ignorant or liars. Similarly, a car can be designed to have features that make it perform better and safer in the event that the driver tries to misuse it. Or it can have a big bullbar on the front with spikes on it. Such a car would be very popular among some sector of the population, but is it a good idea?
There are plenty of guides around on how to best design graphs and slides. These range from relatively easy to near-impossible to actually utilize in PowerPoint.
I was the one that modded it as a troll (and by posting here I am undoing it). It is now modded +5 Funny, and yeah in hindsight it is funny. But at the time I modded it Troll, it was +2 Insightful, which I thought was an abomination. Insightful?
I was thinking in particular over all of the critisism powerpoint (and other packages) have received for making it so easy to produce manipulative and misleading graphics. Plenty of stuff on Edward Tufte's site, eg on Nasa abusing powerpoint to mislead management, resulting in poor decisions, in particular the Columbia accident.
Well, we could go back and forth on this forever. In the end, 'weight' is a definition, and the definition I have been using is the commonly accepted one, in which an object in freefall has a weight of zero. If you don't believe wikipedia on this, there are links to other sites (including any number of NASA) sites elsewhere in this thread.
If you want to define weight differently you are of course free to do so, but do not expect to be able to use your term in a useful conversation! If you want to define 'weight' as the mass times the local gravitational field strength, ignoring motion of the object, then do you also include the (small but non-zero) contribution from the gravitational field of the Sun? Don't forget, that it acts in different directions (ie, either adding or subtracting to the conventionally defined weight) depending on whether the sun is below you (night time) or above you (day time). How would you define your weight on the moon, in your scheme? How does the gravitational field of the Earth (and the Sun, and Jupiter, and...) affect it?
For your question on the acceleration of the rocket, you need to be careful to distinguish the frame of reference. You are completely correct from the frame of reference of the rocket: the impulse of the engines is assumed constant, so as the mass of fuel decreases the acceleration of the rocket increase. This holds no matter whether the rocket is in a gravitational field or not: unless the astronauts looked out the window to see there is no way they can determine whether they are in empty space, or accelerating away from (or towards!) a heavy mass (ie. they cannot determine this by performing experiments to measure the local gravitational field, in all cases they get the same answer! This is the equivalence principle, which is a cornerstone of general relativity).
From the frame of reference of an outside observer on the Earth, the motion of the rocket is certainly affected by gravity. For example, if the acceleration of the rocket just happened to be 9.81m/s^2 then the rocket would be not accelerating relative to an observer on the Earth - he would see it as hovering (or moving at constant velocity relative to the observer). But to the astronauts inside the rocket, they would feel the acceleration as indistinguishable to standing on the surface of the Earth.
What we feel as weight is not the downward force -mg but rather the upward force +mg which we have to exert to resist the downward one. This is what you feel when you do a push-up, for example. In freefall, the downward force -gm is still there, but there is no reaction force acting against it. No rection force = no weight.
Put two objects floating in the ISS a metre or two apart (with the line joining them perpendicular to the direction of motion) and you'll notice that they will move together over the course of a quarter of an orbit (~22mins) due to slightly different orbits that the two objects will be in and the slightly different direction to the CoM of the Earth.
Yes, that is true - that is a very clear example! I was thinking of elevators near the surface of the Earth, which would be quite a tricky experiment to carry out;-)
By the way, if you try to define an 'actual weight' as W=M*g while ignoring your motion, in an attempt to argue that objects in orbit really do have a non-zero `weight', then I counter with the question what about the gravity of the sun? If you are going to count only forces due to gravitational masses, then you properly need to include all masses, not just the closest one. And some of them may be significant!
The mass of the sun is 1.98892 × 10^30 kg, at an average radius of 1.496*10^11m, which gives a local gravitational acceleration at the Earth due to the sun of g=Gm/r^2 = 3.27m/s^2. This is almost 1/3 of the acceleration due to gravity of the Earth itself! Are you trying to argue that the `actual weight' of an object at the surface of the earth should be some 30% higher than what we read on the scales, because of the influence of the sun? Even worse, at the equator it should be 30% higher during midnight, when the sun is in the same direction as the center of the Earth, but at midday it should be 30% less, because the sun is in the opposite direction to the center of the earth!
If that still isn't convincing, think about how you would define your weight if you were standing on the Moon. How should the (smaller, but still relevant) gravity of the Earth affect your `actual weight' ? And how is this situation fundamentally different from being on the ISS?
So, if the force of gravity is acting on you, and nothing else is, then you have no force applied to you? You expand my view of the ridiculous....
Yes from the point of view of an outside observer there is a force on you, but the point about gravity is that it applies equally to every part of your body at once. So, if you are in free fall and you raise your arm, there is no resistance to that motion (other than internal friction in your joints) and no force that would push against your arm that would tend to lower it again. From your point of view, you have no forces acting upon you. But this really means that there are not differences in the force between different parts of your body.
This is in contrast to the situation when you are standing on the surface of the Earth, or being accelerated in a car. In the case of standing on the surface of the earth, you feel a force on your body because, while the overall forces cancel out (so you have no overall motion), the forces are applied in different places. The gravitational force is being applied to every atom in your body equally, but the restoring force that is stopping you from falling into the center of the Earth is being applied at the point where your feet make contact with the ground. The restoring force that is stopping some other part of your body (your hand, for example) from falling into the center of the Earth is being transmitted through your feet and body to your hand. That is why it takes some effort to raise your hand - the gravity is acting directly on your hand, but the restoring force to hold your hand in the air needs to be transmitted through your arm.
If you are in free fall, then there is no difference in the force being applied to different parts of your body, and you cannot even tell that there is any force acting upon you! There is no difference between the situation where (1) you are falling under gravity towards the Earth, with no other forces acting upon you, and (2) you are in empty space with no massive objects anywhere near you. These two situations are completely equivalent, for the effects on your body.
Similarly, there is no difference, as far as the forces on your body are concerned, between standing on the surface of the earth and experiencing your weight of W=M*9.81m/s^2 and being accelerated in a rocket ship at 9.81m/s^2 and experiencing a force holding you to the floor of the spacecraft. The Equivalence Principle of relativity says that the forces on you are exactly the same in both cases.
Note that the wikipedia article has, at best, a limited understanding of the difference between weightlessness and freefall. Which are not, contrary to their assertion, synonyms.
They are not synonyms, because they are two words that have different meanings. Wikipedia does not claim that they are synonyms, by the way. But it is true that if you are in freefall then you are weightless. And the only way that is known to physics for an object with non-zero mass to become weightless is to let it free-fall.
If you refuse to believe Wikipedia, there are plenty of other references you could look at:
Slashdot Mirror
Correct, all air traffic globally is regulated by international law, and in the USA the airspace is administered by the FAA. Unless you go to a huge hassle to get an airworthiness certificate and licenses (a big hassle, and probably impractical unless you are a professional or seriously hardcore enthusiast), you MUST comply with the existing exceptions for radio controlled craft. This means:
Line of sight. You must stay within line of sight of the aircraft, and you also must be able to take control of the aircraft in an emergency.
Altitude restriction, no higher than 400ft. You also need to keep clear of (and give way to) full-scale aircraft (presumably you would never be flying anywhere near a regular airport, but you still may encounter paragliders, sail planes etc).
Keep clear of built up areas. So definitely no barrel roll under a bus!
Finally, it sounds like the submitter is completely new to the field, in which case the place to start is to buy yourself a cheap R/C kit and learn how to fly it. You need to be able to fly R/C anyway so this is surely the best entry into the field. Building your own airframe is possible, but seriously hard: you certainly don't want to do it for your first airframe anyway, because you are almost certainly going to crash it, lots, while learning how to fly R/C, and you want something that will fly well immediately, without extensive tuning. And then, once you start debugging the autopilot, you will probably crash it lots more. Start from a cheap kit, and take it from there.
I think you (and a lot of posters here) are missing a basic point. Which is that you can have your own kids, observe them as much as you like or whatever, but unless you do a very careful and controlled experiment, you cannot distinguish what you think they are doing versus what is actually going on in their brain.
That is the difference that distinguishes science from superstition. The whole history of science is chock full of examples where reality turns out to be different from intuition. Even if your intuition is actually correct in this case, simply knowing for sure that your intuition is correct is useful knowledge. And without a doubt, there are some details about the functioning of your child's brain where your intuition is completely wrong. The process of science is figuring out exactly what that is.
Good question. The answer may be buried in http://en.wikipedia.org/wiki/Iron_fertilization, I'm reading it now.
I expect most of the carbon in a whale ends up in gaseous form, when the flesh decomposes. Some of it would dissolve in the water, but that too is a problem - increasing carbon dioxide concent in sea water is making it more acidic. And there is a saturation point at which there is so much dissolved carbon dioxide in the water that it won't absorb anymore, in which case any emitted gas goes straight into the atmosphere.
Will they care? The primary motivation is arrest statistics, and acting nervous infront of a federal agent is, by itself, probably enough for that.
Were all of them crap? First Contact was a fun movie, and Insurrection was pure Trek, albeit perhaps a bit too cheesy.
Yes, if there was an act of parliament associated with that (I don't know whether there was or not, but I would assume so). Actually this was one I was thinking about, since in the UK there was a real question as to the legality of the war. In the USA, that was never raised as a serious objection, but in the UK they went to great lengths to get a sham legal opinion justifying the legality of the war.
However, I am not sure whether the queen is allowed to get her own legal advice on legislation, prior to signing it. I suspect not, at least as far as I know it has never been done before.
Of course she rubber stamps everything - that is her job. But consider that her function is similar to the president in the old Weimar republic, but whereas the Weimar republic president was an explicitly political position with real power, and subject to influence (specifically, Hindenburg ended up playing into the hands of Hitler), the Monarchy in the UK is, in theory, above all that. Indeed, the Queen is not supposed to even comment publically on politics, although she certainly has a lot of influence, and has weekly meetings with the prime minister. But there is a last resort measure there, to refuse to sign a piece of legislation. It is unlikely to ever happen, and it would probably end up as the last thing the monarchy ever does, but nevertheless the safety net exists. Of course, that is only effective against some big 'Enabling Act' type of legislation, it does nothing against a gradual erosion of civil liberties, which is of course the problem today.
I am not a monarchist, and I'm not saying that it is a system that should be adopted anywhere that doesn't have a historical backing for it, but as far as systems of government go, a constitutional monarchy isn't bad. Compared with the USA, where if the president runs amok there is not much that can be done except impeachment (which is difficult, especially if the congress is controlled by the same political party as the president), it might even have some advantages.
In the UK there is a final arbiter; and that is the Queen, who must sign off on legislation before it becomes law. Nowdays it is mostly ceremonial, I don't think she has exercised the right to not sign legislation for a long time now (if ever, for the current monarch). But it does mean that there is an additional opportunity to stop any Enabling Act type legislation before it becomes law.
In principle, the constitution in the US is a strong document, but in the end it is people who have to uphold it. Primarily, the Justice Department is responsible for giving legal advice to the executive (and, I guess, to congress too?), and if they routinely give advice to the executive that is borderline or illegal, then there is not much recourse. The courts can usually intervene, but that is a slow process - and of course that depends on the courts finding out about the illegal activities in the first place.
But it is true though. Wine on Linux is probably far more backwards compatible for older Windows applications, than new versions of the Windows OS are.
In MS's battles to keep backwards compatibility, something went horribly wrong.
Did the GP actually make a mistake though? P is a subset of NP, but the GP referred to NP _complete_, which is an equivalence class and is not, in any sense, a superset of P (unless P=NP).
I don't get it: my main point was to refute the comment "Astronomers were well aware that the region of sky used for the Hubble deep field was full of distant objects.". You, at least, seem to agree with me that that statement is a bunk, since you allow for the possibility that they see 'nothing' but claim that would sill be interesting (well, maybe, but I doubt it would have been nearly as interesting as what they did see). What, exactly, are you trying to argue?
Wow, what a bunch of historical revisionism. How, exactly, were astronomers supposed to be 'well aware' that that pointing Hubble at a patch of sky where all previous surveys had shown nothing at all, would produce such interesting results?
What actually happened was that the director of the observatory has some 'discretionary' observing time on the telescope, that he/she is completely free to do what they want with, without the usual procedure of submitting an application for approval (a process that is quite competitive). Most likely, a normal application to observe in the deep field would have been rejected, on the grounds that there is insufficient justification and it could easily have ended up as a waste of time. Imagine submitting an application saying "we propose to point this multi-billion dollar instrument at a region of sky that is completely black and as far as we know, contains nothing" ? But Robert Williams, the then-director, decided to devote a large proportion of his discretionary time in 1995 to deep field imaging. The rest is history. And pretty pictures.
Well, since he has survived as director of a DOE lab for over 4 years, and is still managing to keep his sanity, I give him at least a 50% chance of surviving Washington. (As part of his job as director of LBL, he would have probably weekly meetings in Washington for the past 4+ years too, so he is not inexperienced as an administrator and dealing with politicians).
Fair enough, but you need to keep in mind that the problems you describe with medical insurance companies are almost exclusively a US problem. The US medical system is quite unique.
Really? If there was another team active in LA, then why didn't we hear about the arrests?
That is the whole point, the original election promise didn't make sense on lots of levels. But one level where it didn't make sense was to spend a lot of money to install filters for a set of known illegal URL's, and then let people opt-out of the filter. That would be like the police shutting down a brothel by posting a guard at the front door stopping people from entering, while putting up a sign to point out that people are still free to get in through the side entrance.
As soon as it became a tool for blocking illegal sites it was clear it would no longer be optional. If you are going to block illegal stuff, the it makes no sense to let people opt out of it.
Conroy is known as quite a back-room numbers man and power broker, but he isn't very well liked either. There are rumors that he's been set up to take the fall when the filtering scheme fails, along with the almost inevitable failure of the national broadband infrastructure tender process.
Rudd's interest in this is that both the filtering and the national broadband scheme were election promises, and while I admire his integrity in trying to carry through with all of his election promises (unlike the previous mob, who turned election lying into a high art), I really wish he would dump the promises that were clearly stupid. (I see now he has dumped the dumb idea of forming a Department of Homeland Security. That was surely an ill-advised scheme to attract right-wingnuts to vote for the Labor party.)
But the bottom line is that there is a real possibility that Rudd is complicit in setting Conroy up for the fall: he not only gets Conroy out of the front bench (and possibly out of parliament), but he also gets to dump the election promise of internet filtering with the excuse that it isn't his fault that Conroy botched it.
Ok, but it invites you to mislead. It would be quite possible to design it in a way that encourages good practice. I mean, Microsoft are already masters at inane dialog boxes. If clippy popped up and asked "are you sure you want to chop off the axes of this plot?", or "are you sure that your bullet points accurately represent the data?" it would make statisticians very happy (as well as pissed off at the interference :-)
Tools can be designed with a focus on best practice, or they can be designed to appeal to the ignorant or liars. Similarly, a car can be designed to have features that make it perform better and safer in the event that the driver tries to misuse it. Or it can have a big bullbar on the front with spikes on it. Such a car would be very popular among some sector of the population, but is it a good idea?
There are plenty of guides around on how to best design graphs and slides. These range from relatively easy to near-impossible to actually utilize in PowerPoint.
I was the one that modded it as a troll (and by posting here I am undoing it). It is now modded +5 Funny, and yeah in hindsight it is funny. But at the time I modded it Troll, it was +2 Insightful, which I thought was an abomination. Insightful?
I was thinking in particular over all of the critisism powerpoint (and other packages) have received for making it so easy to produce manipulative and misleading graphics. Plenty of stuff on Edward Tufte's site, eg on Nasa abusing powerpoint to mislead management, resulting in poor decisions, in particular the Columbia accident.
Well, we could go back and forth on this forever. In the end, 'weight' is a definition, and the definition I have been using is the commonly accepted one, in which an object in freefall has a weight of zero. If you don't believe wikipedia on this, there are links to other sites (including any number of NASA) sites elsewhere in this thread.
If you want to define weight differently you are of course free to do so, but do not expect to be able to use your term in a useful conversation! If you want to define 'weight' as the mass times the local gravitational field strength, ignoring motion of the object, then do you also include the (small but non-zero) contribution from the gravitational field of the Sun? Don't forget, that it acts in different directions (ie, either adding or subtracting to the conventionally defined weight) depending on whether the sun is below you (night time) or above you (day time). How would you define your weight on the moon, in your scheme? How does the gravitational field of the Earth (and the Sun, and Jupiter, and ...) affect it?
For your question on the acceleration of the rocket, you need to be careful to distinguish the frame of reference. You are completely correct from the frame of reference of the rocket: the impulse of the engines is assumed constant, so as the mass of fuel decreases the acceleration of the rocket increase. This holds no matter whether the rocket is in a gravitational field or not: unless the astronauts looked out the window to see there is no way they can determine whether they are in empty space, or accelerating away from (or towards!) a heavy mass (ie. they cannot determine this by performing experiments to measure the local gravitational field, in all cases they get the same answer! This is the equivalence principle, which is a cornerstone of general relativity).
From the frame of reference of an outside observer on the Earth, the motion of the rocket is certainly affected by gravity. For example, if the acceleration of the rocket just happened to be 9.81m/s^2 then the rocket would be not accelerating relative to an observer on the Earth - he would see it as hovering (or moving at constant velocity relative to the observer). But to the astronauts inside the rocket, they would feel the acceleration as indistinguishable to standing on the surface of the Earth.
What we feel as weight is not the downward force -mg but rather the upward force +mg which we have to exert to resist the downward one. This is what you feel when you do a push-up, for example. In freefall, the downward force -gm is still there, but there is no reaction force acting against it. No rection force = no weight.
Yes, that is true - that is a very clear example! I was thinking of elevators near the surface of the Earth, which would be quite a tricky experiment to carry out ;-)
By the way, if you try to define an 'actual weight' as W=M*g while ignoring your motion, in an attempt to argue that objects in orbit really do have a non-zero `weight', then I counter with the question what about the gravity of the sun? If you are going to count only forces due to gravitational masses, then you properly need to include all masses, not just the closest one. And some of them may be significant!
The mass of the sun is 1.98892 × 10^30 kg, at an average radius of 1.496*10^11m, which gives a local gravitational acceleration at the Earth due to the sun of g=Gm/r^2 = 3.27m/s^2. This is almost 1/3 of the acceleration due to gravity of the Earth itself! Are you trying to argue that the `actual weight' of an object at the surface of the earth should be some 30% higher than what we read on the scales, because of the influence of the sun? Even worse, at the equator it should be 30% higher during midnight, when the sun is in the same direction as the center of the Earth, but at midday it should be 30% less, because the sun is in the opposite direction to the center of the earth!
If that still isn't convincing, think about how you would define your weight if you were standing on the Moon. How should the (smaller, but still relevant) gravity of the Earth affect your `actual weight' ? And how is this situation fundamentally different from being on the ISS?
Yes from the point of view of an outside observer there is a force on you, but the point about gravity is that it applies equally to every part of your body at once. So, if you are in free fall and you raise your arm, there is no resistance to that motion (other than internal friction in your joints) and no force that would push against your arm that would tend to lower it again. From your point of view, you have no forces acting upon you. But this really means that there are not differences in the force between different parts of your body.
This is in contrast to the situation when you are standing on the surface of the Earth, or being accelerated in a car. In the case of standing on the surface of the earth, you feel a force on your body because, while the overall forces cancel out (so you have no overall motion), the forces are applied in different places. The gravitational force is being applied to every atom in your body equally, but the restoring force that is stopping you from falling into the center of the Earth is being applied at the point where your feet make contact with the ground. The restoring force that is stopping some other part of your body (your hand, for example) from falling into the center of the Earth is being transmitted through your feet and body to your hand. That is why it takes some effort to raise your hand - the gravity is acting directly on your hand, but the restoring force to hold your hand in the air needs to be transmitted through your arm.
If you are in free fall, then there is no difference in the force being applied to different parts of your body, and you cannot even tell that there is any force acting upon you! There is no difference between the situation where (1) you are falling under gravity towards the Earth, with no other forces acting upon you, and (2) you are in empty space with no massive objects anywhere near you. These two situations are completely equivalent, for the effects on your body.
Similarly, there is no difference, as far as the forces on your body are concerned, between standing on the surface of the earth and experiencing your weight of W=M*9.81m/s^2 and being accelerated in a rocket ship at 9.81m/s^2 and experiencing a force holding you to the floor of the spacecraft. The Equivalence Principle of relativity says that the forces on you are exactly the same in both cases.
They are not synonyms, because they are two words that have different meanings. Wikipedia does not claim that they are synonyms, by the way. But it is true that if you are in freefall then you are weightless. And the only way that is known to physics for an object with non-zero mass to become weightless is to let it free-fall.
If you refuse to believe Wikipedia, there are plenty of other references you could look at:
http://en.allexperts.com/q/Physics-1358/free-fall-weightless-ness.htm
http://www.windows.ucar.edu/tour/link=/teacher_resources/weightlessness_edu.html
http://www.physics.umd.edu/lecdem/services/demos/demosc4/c4-54.htm
http://www.nasa.gov/centers/glenn/shuttlestation/station/microgex.html
http://www.hq.nasa.gov/office/pao/History/SP-4026/noord27.html