"where water takes a lot of energy to turn into steam."
IMO, that can probably be helped along by the environment. There's heat from the sun and waste heat from the craft itself (hard vacuum: the ultimate in thermal insulation), and there's also the option of cheating by depressurizing the water.
But well, they are build by ESA, so of course they are off limits for the NASA."
First off, if you're going to use something as vague as "plasma engine," you're bound to have it come back and bite you. On 12 October 1975 and 1 September 1976, the US Navy and NASA launched the Triad 2 and TIP 3 spacecraft respectively. Both of them successfully tested a pulsed plasma engine (amongst other things). My source.
(For those of you keeping track at home, the ESA didn't even exist until April 1974.)
"With Plasma Engines the trip would take roughly 33 days..."
That's interesting. JPL's VASIMR says it will take 3 months. Where are you getting your number?
Not that your number actually matters even if its correct. To provide the kind of specific impulse needed for a manned mission to Mars with a plasma-based engine, you're going to need a lot of electricity, so much that you'll need your own nuclear reactor. And it's pretty much accepted that the US Navy is the world leader in making small, efficient and safe nuclear reactors.
"The idea that a commercial entity can incur an actionable loss because of the freedom of speech is a new and dangerous trend in our society right now"
"New trend?" Apparently you're not familar with slander/libel laws.
It's called Project Orion. Several proof-of-concept flights using plastic explosives were successful. Of course, it's not quite as fun as a nuclear salt-water rocket, which makes Orion look as environmentally friendly as solar power.:)
However, I think they have something in mind more along the lines of NERVA, which involves pumping the reaction mass through an ordinary fission reactor. It's just like a chemical, combustion-based rocket, except the thermal energy is produced by the reactor instead of combustion, and you can get a lot more oomph.
"The people who are most decisively against GW's politics are also those who are most for space exploration."
Who, the Democrats? Let me show you a quote from a town hall meeting with Al Gore in '99
Q: Are you willing to take a bold step and leave us with a legacy of having a man on Mars by 2010?
A: First, as the recent two failures of these robotic landers show, there's still a lot we don't know. Second, the cost is a completely different order of magnitude as the cost of a moon program. There's no doubt that eventually we will land a human being on Mars. But we are right now not at a point where it makes good sense. We've got to get to universal health care. We've got to revolutionize our schools
That right there is why I didn't vote for Gore. Bush has essentially been mute on the top of space exploration to this day.
"Think of it as a distraction from the pending war,"
The same could be said about the Apollo program (Vietnam). Does that make it any less signifigant?
"Some of GW's closest friends and allies are going to reap billions from the program."
By all accounts, GW's "closest friends and allies" are in the oil industry (where he's originally from). But he seems to be pusing a nuclear solution, and nuclear power is oil's greatest foe.
"Defense companies love space projects"
They're already quite happy with the current missile defense program. A Mars mission has little (if any) defense-related spin-offs. At the very least, none of the spin-offs will be defense-only. We'll see things like more efficient nuclear reactor designs, faster/smaller computers, and other things that benefit not only the military but the private sector and consumers as well.
The only way there could possibly be military-only spin-offs from a Mars mission is if we have to fight a bunch of Martians in the near future.
"good for the local economy for years after he's out of office."
Name one president that has gone into state government after having served as president.
"There's no way that the program can be finished before 2010 (we'll be VERY lucky to get it by then)"
"There's no way that the program can be finished before 1970..."
And the nay-sayers then had better reasons to nay-say as well. Unlike the NASA of the early 1960's, we can reach LEO.
"It's about sending millions/billions to defense contractors"
Why not "It's about advancing US nuclear reactor technology enough to replace our hydrocarbon-based power plants with generators that don't fund al Quaeda?"
Why not "It's about justifying the existence of (and spending on) the ISS by using it for its intended purpose?"
Why not "It's about advancing space transportation technology enough so that private enterprise will finally start picking up the tab?"
"Two words for those that say I am wrong. "Superconductor Supercollider"."
Apples and oranges. Space exploration is more popular and interesting to the public than a cyclotron by leaps and bounds.
Consider how you'll always manage to find news on a current manned space mission on Google News (today it's about Columbia's mission). And I'm not just talking about "on the page," every day since lift-off it's been in the "Top Stories" section. It doesn't make it on there if it's not a popular story.
Or always at rest. Or anything in between. You can proove that we're always in motion. I can proove we're always at rest. We'd both be right.
"and don't have the equipment to measure an absolute (i.e., relative to the universe as a whole) reference."
It's not that "we don't have the technology," it's that special relativity says there is no absolute. You can't use the fabric of space-time as an absolute because measurement of space and time is relative to the observer.
If there were an absolute frame of reference, then not all observers would measure c to be ~3E8 m/s relative to themselves, and they could use that difference to extrapolate an absolute frame of reference. It doesn't matter if you're standing on the earth's surface or flying away from it at.99c, you always measure the speed of a beam of light coming from the earth's surface as ~3E8 m/s relative to you.
In terms of Newtonian mechanics, c +.99 c = c
"When clock A looks at Clock B and sees 8:58, and it knows that clock B is two light-minutes away, clock A knows that clock B _should_ say 9:00"
"Should" has nothing to do with it. All physical evidence demonstrates that the clock says 8:58.
"and if we were to instantly go from B to A that we would see 9:00."
First off, there is no such thing as "instantly." Two events occur simultaneously only to a particular frame of reference.
Secondly, according to special relativity, if you were able to travel faster than light, when you got to clock B it would still say 8:58. As far as you would be concerned, you just travelled backwards in time.
That's not relativity, that's the concept of causality. Relativity states that the time-order of two events can be whatever you want them to be so long as you can achieve the proper velocity. For an observer moving faster than light, the two events will be reversed ("effect" precedes "cause"). Causality is just a hunch that has survived to this day because of our inability to find any tachyons.
Causality, relativity, FTL. Pick any two.
"If the sun vanishes now, it doesn't vanish eight minutes later "for us," we just only notice it eight minutes later."
Physics is all about our ability to measure and interact with the rest of the universe. Special relativity assures us that any and all scientific, physical evidence for the sun's existence is still there on the earth. Therefore, for literally all intents and purposes, the sun is still there.
Saying that the sun "really" disappeared eight minutes ago presupposes a preferred frame of reference, an absolute frame that is somehow "more right" than another. Special relativity states that there is no such frame.
(Oh, and for an observer travelling sufficiently faster than c, the earth will leave its orbit eight minutes before the sun vanishes.)
"There really really is an objective reality and an absolute time frame & spaital system"
Proove it. All physical evidence collected in the past century or so in the study of special relativity says that you're wrong, but I will welcome hard evidence to the contrary if you can produce it.
"but it's not labled, and we have no way to see it,"
If it can't be detected/measured/etc., then as far as physics is concerned it doesn't exist.
"so those that "get" astrology tend to ignore the fact that we're just dealing with what we can percieve,"
I won't harp on your use of the word "astrology." However, you're getting hung up on the term "perception." As far as physics and pretty much all science is concerned, perception is reality. Science is the study of the measurable, observable universe. If it cannot be touched, heard, seen, measured, clocked, or otherwise detected, if it doesn't interact with the rest of the universe in any conceivable way, shape or form, then it is outside the realm of science.
You can say "It's there but we just can't detect it" all you want. Until you are able to detect it, it is purely conjecture. And, in this case, it happens to be conjecture that flies in the face of a century of physical evidence pointing to the contrary.
(I'm not saying it's impossible, I'm saying I'll believe it when I see it.)
"This doesn't require any knowledge of relativity - even in Newtonian mechanics this would happen."
Newtonian mechanics says the clock disappeared 8 minutes ago. Special relativity says the clock was 8 minutes slow in the earth frame of reference.
There is no frame of reference where you can say "it actually..." because there is no frame of reference that is more correct than any other. Measurement of time and space is relative to the observer.
That's why all observers measure c relative to them as the same value in all conditions. If there were a preferred frame of reference, then c would be different for different observers. But a century of experimental evidence shows the case to be otherwise.
"No, it has ACTUALLY happened in his frame of reference, he just hasn't SEEN it yet."
If you can't see it, hear it, or otherwise proove its existence (or lack thereof), the event hasn't happened yet. The only way the observer will know that it has (will) happened is if he has some sort of prior knowledge of a pre-arranged schedule, But that foresight doesn't mean the event happens in his frame of reference any sooner. And his frame of reference is just as valid as anybody else's frame of reference.
"Again, he doesn't need to know anything about relativity to determine this, it would work the same way in Newtonian mechanics."
Newtonian mechanics say that the delay between the sun disappearing and the earth noticing will be measured as the same for all observers. Special relativity says that there is no absolute frame of reference for the measurement of time. It will be different for different people based on location and velocity relative to the event. I can give you observers that will say that that delay is anywhere between "instantaneous" and "forever," and all of these measurements will be 100% valid.
In fact, special relativity states that if an observer is able to move faster than light, they will see the earth leave its orbital path before the sun disappeared. And that observation as well would be 100% correct.
"12:00 on Earth is truly in the Past for the moving observer even though 12:00 on the Sun is Now."
You assume that one clock is "more correct" than the other two. Special relativity says that all the clocks are correct for all observers.
An earth-bound observer will see the spacecraft's clock as two minutes slow, and he will be correct. The astronaut will see the earth-bound clock as two minutes slow, and he too will be correct. They are both correct because there is no absolute frame of reference.
"No. But, when you first see the Sun peek over the horizon, the light you're seeing left the Sun eight minutes before. The fact that you aren't seeing it until now doesn't mean it didn't happen until now."
Proove it with experimental evidence. Give me hard evidence that the light I'm seeing from the sun left the sun eight minutes ago.
For every observer that you give me that says "eight minutes," I can give you an infinite number of observers that will give you an infinite number of measurements, none of which are eight minutes. And they will all have physical evidence prooving their observations.
"and determine that they really did vanish at different times"
He can compute whatever he wants. In his frame of reference, they really did disappear at the same time. His computations have no effect on the reality of the situation in his frame of reference.
"the Earth slighty before the Sun. The observer on Earth would see Earth vanish, see the Sun vanish eight minutes later, and calculate that they both vanished precisely at 12:00. They would both be correct, for their own frame of reference."
No, they're only correct for the frame of reference of the half-way point, which isn't any better than earth-based or sun-based observations. The observers can calculate whatever they want, but (barring quantum mechanics) as far as reality is concerned at their individual frames of references, there was an eight minute gap between the two occurrences. All physical evidence that can possibly be gathered by those two observers will demonstrate that eight minute gap.
It's obvious from your posts that you know little about what special relativity says. Why don't you try reading a little about the classic barn and pole scenario before you try responding again.
"Interestingly, an observer on Earth will see the Sun's clock saying 12:00. They will realize that the Sun has really been gone for eight minutes."
Can he prove it? No. Until the "sun's gone" signal reaches Earth, for all intents and purposes it is still there. There is still light and heat coming from it, and there is still its gravitational influence on everything in the star system. Special relativity says that you can't prove that isn't the case.
All he knows is that, according to an observer equidistant from both the sun and the earth, the sun will disappear eight minutes before the earth reacts accordingly. But that doesn't mean a damn thing to the people on the earth, and it can't ever mean anything because that observer's communication of "Hey, the sun is gone" is also limited by relativity.
"When the Sun's clock reads 12:08, this observer knows that Earth is moving out of orbit - but he won't see it happen until the light from Earth comes back."
"Knowing" has nothing to do with it. His knowledge of special relativity allows him to predict what will eventually happen (which is the point of studying physics), but as far as the sun-based observer is concerned, it hasn't happened yet. He can still see the reflected light off the earth and he can still feel its gravitational influence.
I know the sun will rise in my time zone in about six hours. Does that mean it's already happened?
"Where relativity comes into play is if we have a moving observer going at, let's say 0.5c. When this observer looks at the clocks on Earth and Sun, they will not be synchronized EVEN AFTER he corrects for the travel time of the light."
His clock is fine. It's the rest of us that are moving at 0.5 c, and ours are the clocks that are moving slow. And there's no way you can proove that one observation is "more correct" than the other, because Einstein tells us that both observations are equally valid.
Because c isn't just the speed of light, it's the speed of change through the universe. Every change in the universe, every interaction between two objects can only move at the speed of light. And if that change in the universe "hasn't reached you" yet, then for every conceivable purpose it simply hasn't happened yet. Period.
"I look out the window, with my powerful telescope and see yesterdays newspaper back on earth."
Here's the tricky part: It's not just that you're seeing an image that left your home yesterday, it's that you are actually looking at yesterday. Yesterday's reality is washing over you like a wave at the beach.
If you see yourself in that telescope, that's not just an image of you, that is you. Changes you made in the universe, everything you did "yesterday" is happening now, as you watch it. As far as space, time, and the universe (from where you sit) are concerned, you are now in two places at the same time. If you were able to step back into your teleportation device, you would end up back on the earth "yesterday."
There's a more drawn-out explaination of the circumstances and the consequences using the classic example of a duel with tachyon pistols here
"Just because no force can travel faster than c doesn't mean that time is all wacky."
Yes, it does. Special relativity says that no frame of reference is any more "correct" than any other when it comes to measuring time and space. Space and time "rearrange themselves" (or, more honestly, you perceive them to be rearranged) so that c relative to you is ~3E8 m/s no matter what you do.
"If you take two syncronized clocks, travel for one light-minute in opposite diretions at equal speeds, and then smash one of the clocks when it reads 9:00 a.m., the other clock can know that it lots its twin when IT says "9:00 a.m.", not when it says 9:02 a.m."
When clock A is smashed, it will look back across the two light-minute gap and see that clock B reads 8:58. Clock A will know that clock B is two minutes slow and it will be correct.
When clock B sees clock A is smashed, it will see clock A read 9:00 while clock B itself read 9:02. Clock B will know that clock A was two minutes slow when it was smashed and it will be correct.
Both are correct. Neither one is more correct than the other because neither frame of reference is any better or more provable than the other. That's special relativity.
"Of course, if you really understood it"
If you really understood it, you wouldn't have stuck your foot in your mouth like you did with your very first sentence. Unless you have some astounding new evidence of a flaw in the theory of special relativity (something nobody has done in about a century or so), this is the way the universe works.
"For one thing, if gravity was instananeous it could conceivably be used to send information anywhere in the universe with zero ping time."
According to special relativity, if gravity (or any other form of information transmittal) were instantaneous, you could talk to yourself in the past.
If FTL anything is possible and special relativity still holds true, FTL = time travel. It also throws the concept of causality out the window (and the concepts of "consciousness" and "free will" along with it).
"My bathroom scales don't measure weight, they measure mass."
Unless your bathroom scale is a beam-balance scale, it measures weight. If it measured mass, it would read exactly the same on the surface of the moon (as well as any latitude on Earth) with no adjustments necessary.
Scales ordinarily found in typical consumer bathrooms, grocery stores, etc. measure the amount of tension or compression placed on a spring (or some electromechanical device). It measures the force put on the spring, therefore it measures weight, not mass.
"People just don't like change, and whine at anything that will cause any kind of bother, even if it's minor and short lived."
We'll change to using metric-only just as soon as every other country in the world changes their national language to English.
"I moved to Canada a few years ago which isn't just metric, but ISO too (that means the weatherman uses kilo-Pascals rather than the metric sounding milli-bars.)"
Does your bathroom scale tell you your weight in Newtons, or "kilograms?"
"Who in his right mind would like to have his brain fondled by a MS product?"
My answer to that question depends entirely on who wrote the hardware drivers. Windows may have its flaws, but at least 99.9% of the hardware out there works with it out of the box.
"The apostrophe is used to indicated contraction and possetion"
The posession bit only works with proper nouns, such as "Mike's" or "Joe's." The posessive pronoun is spelled "its." If you had to include the apostrophy in the pronouns, you'd also be spelling the masculine pronoun "hi's".
"Tell me again how one puts a "virus-worm hybrid" into a non-executable file and have it infect mp3 players on multiple platforms?"
Possibly the same way non-executable e-mail text can be infected: Through the "feature" set in a Microsoft client. Remember the good ol' days when there was no such thing as an e-mail virus?
Slashdot Mirror
"where water takes a lot of energy to turn into steam."
IMO, that can probably be helped along by the environment. There's heat from the sun and waste heat from the craft itself (hard vacuum: the ultimate in thermal insulation), and there's also the option of cheating by depressurizing the water.
" We allredy have Plasma Engines as well.
..."
But well, they are build by ESA, so of course they are off limits for the NASA."
First off, if you're going to use something as vague as "plasma engine," you're bound to have it come back and bite you. On 12 October 1975 and 1 September 1976, the US Navy and NASA launched the Triad 2 and TIP 3 spacecraft respectively. Both of them successfully tested a pulsed plasma engine (amongst other things). My source.
(For those of you keeping track at home, the ESA didn't even exist until April 1974.)
"With Plasma Engines the trip would take roughly 33 days
That's interesting. JPL's VASIMR says it will take 3 months. Where are you getting your number?
Not that your number actually matters even if its correct. To provide the kind of specific impulse needed for a manned mission to Mars with a plasma-based engine, you're going to need a lot of electricity, so much that you'll need your own nuclear reactor. And it's pretty much accepted that the US Navy is the world leader in making small, efficient and safe nuclear reactors.
"Suppose you stand outside the restaurant telling people you got food poisoning while eating there. You have a constitutional right to do so."
If you're lying about it, the owner of the restaurant has the right to sue you for slander/libel.
"freedom of speech" != "freedom from responsibility"
"The idea that a commercial entity can incur an actionable loss because of the freedom of speech is a new and dangerous trend in our society right now"
"New trend?" Apparently you're not familar with slander/libel laws.
It's called Project Orion. Several proof-of-concept flights using plastic explosives were successful. Of course, it's not quite as fun as a nuclear salt-water rocket, which makes Orion look as environmentally friendly as solar power. :)
However, I think they have something in mind more along the lines of NERVA, which involves pumping the reaction mass through an ordinary fission reactor. It's just like a chemical, combustion-based rocket, except the thermal energy is produced by the reactor instead of combustion, and you can get a lot more oomph.
Who, the Democrats? Let me show you a quote from a town hall meeting with Al Gore in '99That right there is why I didn't vote for Gore. Bush has essentially been mute on the top of space exploration to this day.
"Think of it as a distraction from the pending war,"
The same could be said about the Apollo program (Vietnam). Does that make it any less signifigant?
"Some of GW's closest friends and allies are going to reap billions from the program."
By all accounts, GW's "closest friends and allies" are in the oil industry (where he's originally from). But he seems to be pusing a nuclear solution, and nuclear power is oil's greatest foe.
"Defense companies love space projects"
They're already quite happy with the current missile defense program. A Mars mission has little (if any) defense-related spin-offs. At the very least, none of the spin-offs will be defense-only. We'll see things like more efficient nuclear reactor designs, faster/smaller computers, and other things that benefit not only the military but the private sector and consumers as well.
The only way there could possibly be military-only spin-offs from a Mars mission is if we have to fight a bunch of Martians in the near future.
"good for the local economy for years after he's out of office."
Name one president that has gone into state government after having served as president.
"There's no way that the program can be finished before 2010 (we'll be VERY lucky to get it by then)"
"There's no way that the program can be finished before 1970..."
And the nay-sayers then had better reasons to nay-say as well. Unlike the NASA of the early 1960's, we can reach LEO.
"It's about sending millions/billions to defense contractors"
Why not "It's about advancing US nuclear reactor technology enough to replace our hydrocarbon-based power plants with generators that don't fund al Quaeda?"
Why not "It's about justifying the existence of (and spending on) the ISS by using it for its intended purpose?"
Why not "It's about advancing space transportation technology enough so that private enterprise will finally start picking up the tab?"
"Two words for those that say I am wrong. "Superconductor Supercollider"."
Apples and oranges. Space exploration is more popular and interesting to the public than a cyclotron by leaps and bounds.
Consider how you'll always manage to find news on a current manned space mission on Google News (today it's about Columbia's mission). And I'm not just talking about "on the page," every day since lift-off it's been in the "Top Stories" section. It doesn't make it on there if it's not a popular story.
"about all they're going to find up there"
He says on an IC-based computer, a spin-off of the Apollo program...
By 2010 we should have launched a second manned mission to Jupiter! It's supposed to be a combined US/Russian endeavor...
Where's my Pan Am flight to the moon!?
"That's because we're always in motion,"
.99c, you always measure the speed of a beam of light coming from the earth's surface as ~3E8 m/s relative to you.
.99 c = c
Or always at rest. Or anything in between. You can proove that we're always in motion. I can proove we're always at rest. We'd both be right.
"and don't have the equipment to measure an absolute (i.e., relative to the universe as a whole) reference."
It's not that "we don't have the technology," it's that special relativity says there is no absolute. You can't use the fabric of space-time as an absolute because measurement of space and time is relative to the observer.
If there were an absolute frame of reference, then not all observers would measure c to be ~3E8 m/s relative to themselves, and they could use that difference to extrapolate an absolute frame of reference. It doesn't matter if you're standing on the earth's surface or flying away from it at
In terms of Newtonian mechanics, c +
"When clock A looks at Clock B and sees 8:58, and it knows that clock B is two light-minutes away, clock A knows that clock B _should_ say 9:00"
"Should" has nothing to do with it. All physical evidence demonstrates that the clock says 8:58.
"and if we were to instantly go from B to A that we would see 9:00."
First off, there is no such thing as "instantly." Two events occur simultaneously only to a particular frame of reference.
Secondly, according to special relativity, if you were able to travel faster than light, when you got to clock B it would still say 8:58. As far as you would be concerned, you just travelled backwards in time.
More information on this here.
"that is, one moment always follows the next"
That's not relativity, that's the concept of causality. Relativity states that the time-order of two events can be whatever you want them to be so long as you can achieve the proper velocity. For an observer moving faster than light, the two events will be reversed ("effect" precedes "cause"). Causality is just a hunch that has survived to this day because of our inability to find any tachyons.
Causality, relativity, FTL. Pick any two.
"If the sun vanishes now, it doesn't vanish eight minutes later "for us," we just only notice it eight minutes later."
Physics is all about our ability to measure and interact with the rest of the universe. Special relativity assures us that any and all scientific, physical evidence for the sun's existence is still there on the earth. Therefore, for literally all intents and purposes, the sun is still there.
Saying that the sun "really" disappeared eight minutes ago presupposes a preferred frame of reference, an absolute frame that is somehow "more right" than another. Special relativity states that there is no such frame.
(Oh, and for an observer travelling sufficiently faster than c, the earth will leave its orbit eight minutes before the sun vanishes.)
"There really really is an objective reality and an absolute time frame & spaital system"
Proove it. All physical evidence collected in the past century or so in the study of special relativity says that you're wrong, but I will welcome hard evidence to the contrary if you can produce it.
"but it's not labled, and we have no way to see it,"
If it can't be detected/measured/etc., then as far as physics is concerned it doesn't exist.
"so those that "get" astrology tend to ignore the fact that we're just dealing with what we can percieve,"
I won't harp on your use of the word "astrology." However, you're getting hung up on the term "perception." As far as physics and pretty much all science is concerned, perception is reality. Science is the study of the measurable, observable universe. If it cannot be touched, heard, seen, measured, clocked, or otherwise detected, if it doesn't interact with the rest of the universe in any conceivable way, shape or form, then it is outside the realm of science.
You can say "It's there but we just can't detect it" all you want. Until you are able to detect it, it is purely conjecture. And, in this case, it happens to be conjecture that flies in the face of a century of physical evidence pointing to the contrary.
(I'm not saying it's impossible, I'm saying I'll believe it when I see it.)
"This doesn't require any knowledge of relativity - even in Newtonian mechanics this would happen."
Newtonian mechanics says the clock disappeared 8 minutes ago. Special relativity says the clock was 8 minutes slow in the earth frame of reference.
There is no frame of reference where you can say "it actually..." because there is no frame of reference that is more correct than any other. Measurement of time and space is relative to the observer.
That's why all observers measure c relative to them as the same value in all conditions. If there were a preferred frame of reference, then c would be different for different observers. But a century of experimental evidence shows the case to be otherwise.
"No, it has ACTUALLY happened in his frame of reference, he just hasn't SEEN it yet."
If you can't see it, hear it, or otherwise proove its existence (or lack thereof), the event hasn't happened yet. The only way the observer will know that it has (will) happened is if he has some sort of prior knowledge of a pre-arranged schedule, But that foresight doesn't mean the event happens in his frame of reference any sooner. And his frame of reference is just as valid as anybody else's frame of reference.
"Again, he doesn't need to know anything about relativity to determine this, it would work the same way in Newtonian mechanics."
Newtonian mechanics say that the delay between the sun disappearing and the earth noticing will be measured as the same for all observers. Special relativity says that there is no absolute frame of reference for the measurement of time. It will be different for different people based on location and velocity relative to the event. I can give you observers that will say that that delay is anywhere between "instantaneous" and "forever," and all of these measurements will be 100% valid.
In fact, special relativity states that if an observer is able to move faster than light, they will see the earth leave its orbital path before the sun disappeared. And that observation as well would be 100% correct.
"12:00 on Earth is truly in the Past for the moving observer even though 12:00 on the Sun is Now."
You assume that one clock is "more correct" than the other two. Special relativity says that all the clocks are correct for all observers.
An earth-bound observer will see the spacecraft's clock as two minutes slow, and he will be correct. The astronaut will see the earth-bound clock as two minutes slow, and he too will be correct. They are both correct because there is no absolute frame of reference.
"No. But, when you first see the Sun peek over the horizon, the light you're seeing left the Sun eight minutes before. The fact that you aren't seeing it until now doesn't mean it didn't happen until now."
Proove it with experimental evidence. Give me hard evidence that the light I'm seeing from the sun left the sun eight minutes ago.
For every observer that you give me that says "eight minutes," I can give you an infinite number of observers that will give you an infinite number of measurements, none of which are eight minutes. And they will all have physical evidence prooving their observations.
"and determine that they really did vanish at different times"
He can compute whatever he wants. In his frame of reference, they really did disappear at the same time. His computations have no effect on the reality of the situation in his frame of reference.
"the Earth slighty before the Sun. The observer on Earth would see Earth vanish, see the Sun vanish eight minutes later, and calculate that they both vanished precisely at 12:00. They would both be correct, for their own frame of reference."
No, they're only correct for the frame of reference of the half-way point, which isn't any better than earth-based or sun-based observations. The observers can calculate whatever they want, but (barring quantum mechanics) as far as reality is concerned at their individual frames of references, there was an eight minute gap between the two occurrences. All physical evidence that can possibly be gathered by those two observers will demonstrate that eight minute gap.
It's obvious from your posts that you know little about what special relativity says. Why don't you try reading a little about the classic barn and pole scenario before you try responding again.
"Interestingly, an observer on Earth will see the Sun's clock saying 12:00. They will realize that the Sun has really been gone for eight minutes."
Can he prove it? No. Until the "sun's gone" signal reaches Earth, for all intents and purposes it is still there. There is still light and heat coming from it, and there is still its gravitational influence on everything in the star system. Special relativity says that you can't prove that isn't the case.
All he knows is that, according to an observer equidistant from both the sun and the earth, the sun will disappear eight minutes before the earth reacts accordingly. But that doesn't mean a damn thing to the people on the earth, and it can't ever mean anything because that observer's communication of "Hey, the sun is gone" is also limited by relativity.
"When the Sun's clock reads 12:08, this observer knows that Earth is moving out of orbit - but he won't see it happen until the light from Earth comes back."
"Knowing" has nothing to do with it. His knowledge of special relativity allows him to predict what will eventually happen (which is the point of studying physics), but as far as the sun-based observer is concerned, it hasn't happened yet. He can still see the reflected light off the earth and he can still feel its gravitational influence.
I know the sun will rise in my time zone in about six hours. Does that mean it's already happened?
"Where relativity comes into play is if we have a moving observer going at, let's say 0.5c. When this observer looks at the clocks on Earth and Sun, they will not be synchronized EVEN AFTER he corrects for the travel time of the light."
His clock is fine. It's the rest of us that are moving at 0.5 c, and ours are the clocks that are moving slow. And there's no way you can proove that one observation is "more correct" than the other, because Einstein tells us that both observations are equally valid.
"Why?"
Because c isn't just the speed of light, it's the speed of change through the universe. Every change in the universe, every interaction between two objects can only move at the speed of light. And if that change in the universe "hasn't reached you" yet, then for every conceivable purpose it simply hasn't happened yet. Period.
"I look out the window, with my powerful telescope and see yesterdays newspaper back on earth."
Here's the tricky part: It's not just that you're seeing an image that left your home yesterday, it's that you are actually looking at yesterday. Yesterday's reality is washing over you like a wave at the beach.
If you see yourself in that telescope, that's not just an image of you, that is you. Changes you made in the universe, everything you did "yesterday" is happening now, as you watch it. As far as space, time, and the universe (from where you sit) are concerned, you are now in two places at the same time. If you were able to step back into your teleportation device, you would end up back on the earth "yesterday."
There's a more drawn-out explaination of the circumstances and the consequences using the classic example of a duel with tachyon pistols here
"Just because no force can travel faster than c doesn't mean that time is all wacky."
Yes, it does. Special relativity says that no frame of reference is any more "correct" than any other when it comes to measuring time and space. Space and time "rearrange themselves" (or, more honestly, you perceive them to be rearranged) so that c relative to you is ~3E8 m/s no matter what you do.
"If you take two syncronized clocks, travel for one light-minute in opposite diretions at equal speeds, and then smash one of the clocks when it reads 9:00 a.m., the other clock can know that it lots its twin when IT says "9:00 a.m.", not when it says 9:02 a.m."
When clock A is smashed, it will look back across the two light-minute gap and see that clock B reads 8:58. Clock A will know that clock B is two minutes slow and it will be correct.
When clock B sees clock A is smashed, it will see clock A read 9:00 while clock B itself read 9:02. Clock B will know that clock A was two minutes slow when it was smashed and it will be correct.
Both are correct. Neither one is more correct than the other because neither frame of reference is any better or more provable than the other. That's special relativity.
"Of course, if you really understood it"
If you really understood it, you wouldn't have stuck your foot in your mouth like you did with your very first sentence. Unless you have some astounding new evidence of a flaw in the theory of special relativity (something nobody has done in about a century or so), this is the way the universe works.
"For one thing, if gravity was instananeous it could conceivably be used to send information anywhere in the universe with zero ping time."
According to special relativity, if gravity (or any other form of information transmittal) were instantaneous, you could talk to yourself in the past.
If FTL anything is possible and special relativity still holds true, FTL = time travel. It also throws the concept of causality out the window (and the concepts of "consciousness" and "free will" along with it).
"The sun can't suddenly disappear."
It can if you hook it up to an infinite improbability drive.
(Douglas Adams books and Road Runner cartoons make more sense the more quantum you learn)
"would the Earth continue to hold its orbit for 8 or so minutes, or would it go whizzing off into space instantly?"
Yes and yes.
For an observer on Earth, the planet will start leaving the star system as soon as the sun vanishes.
For an observer equidistant from both the sun and the earth, the earth will start flying out of the star system ~8.5 minutes after the sun vanishes.
For an observer on/near the sun, the earth will start to leave its path ~17 minutes after the sun vanishes.
And they're all right. Ain't relativity grand?
"My bathroom scales don't measure weight, they measure mass."
Unless your bathroom scale is a beam-balance scale, it measures weight. If it measured mass, it would read exactly the same on the surface of the moon (as well as any latitude on Earth) with no adjustments necessary.
Scales ordinarily found in typical consumer bathrooms, grocery stores, etc. measure the amount of tension or compression placed on a spring (or some electromechanical device). It measures the force put on the spring, therefore it measures weight, not mass.
"For those of you using sane units, this is about 250 gigabits per cm^2."
Closer to 270 GB per cm^2. If you're using "sane" units, then there's 1000 bytes/kilobytes/megabytes in a kilobyte/megabyte/gigabyte, not 1024.
SI is base-10 only. If you're going to insinuate that SI is the "one true measuring system," you had best get it right.
"People just don't like change, and whine at anything that will cause any kind of bother, even if it's minor and short lived."
We'll change to using metric-only just as soon as every other country in the world changes their national language to English.
"I moved to Canada a few years ago which isn't just metric, but ISO too (that means the weatherman uses kilo-Pascals rather than the metric sounding milli-bars.)"
Does your bathroom scale tell you your weight in Newtons, or "kilograms?"
"Who in his right mind would like to have his brain fondled by a MS product?"
My answer to that question depends entirely on who wrote the hardware drivers. Windows may have its flaws, but at least 99.9% of the hardware out there works with it out of the box.
"And by doing so, the "rich world" will eventually give away so much work that they will be poor."
How will outsourcing what is essentially a manufacturing industry to other parts of the world seriously hurt a services-based economy like the US?
"They'd have to prove computers have no other use besides playing media."
Well, what do you do with your computer, then? For the most part, I use mine to browse the web (media) and play games (media).
"The apostrophe is used to indicated contraction and possetion"
The posession bit only works with proper nouns, such as "Mike's" or "Joe's." The posessive pronoun is spelled "its." If you had to include the apostrophy in the pronouns, you'd also be spelling the masculine pronoun "hi's".
"Tell me again how one puts a "virus-worm hybrid" into a non-executable file and have it infect mp3 players on multiple platforms?"
Possibly the same way non-executable e-mail text can be infected: Through the "feature" set in a Microsoft client. Remember the good ol' days when there was no such thing as an e-mail virus?