The incremental approach is precisely why we don't yet have a HAL-like intelligent machine. That's the approach that's been used up to now by the GOFAI community and it has failed miserably. If the goal of an AI researcher is to understand human cognition, the problem is indeed too big. The interconnectedness of human cognition is so astronomically complex as to be intractable to formal solutions. This problem is too big for any approach, incremental or otherwise. Therefore the goal of the sensible AI researcher is not to develop a theory of cognition, but to discover the fundamental principles that govern the emergence of intelligence. Let's get the damn thing to learn first. We can worry about what it's thinking later. We need an overarching theory of the brain. We don't need limited, isolated bits of cognition.
You're right. Brooks has created a few glorified toys and made a name for himself. MIT's Technology Review refers to him as "The Lord of the Robots". It's all PR. The AI community has failed on its promise to create a human-level artificial intelligence and they've been at it for fifty years! So what do we do? We throw more money at them. Makes sense. Not! We need new ideas and new blood in AI research. The tax-paying public should not be forced to reward failure.
What is analog about a spike fired by a neuron, pray tell? What is analog about DNA? Tilden should stick to his toys, IMO, because that's all he'll ever build. In the meantime, real AI researchers will conduct experiments in temporal spiking networks.
Sure, you've got to start with reliable components, but you have to combine them in just the right way, too.
First off, we should learn a lesson from biology. The bee, for example, has about a million interconnected neurons. Yet the bee's highly sophisticated behavior is extremely robust and efficient. How does nature do it? The answer has to do with parallelism and expectations.
1. Parallel processing insures that signals are not delayed, i.e., their relative arrival times are guaranteed to be consistent.
2. Expectations are assumptions that neurons make about the relative order of signal arrival times.
We can emulate the robustness of nature by first realizing that computing is really a genus of a species known as signal processing. We can obtain very high reliability by emulating the parallelism of nature and enforcing a program's expectations about the temporal order of messages: no signal/message should arrive before its time. The use of stringent timing constraints will ensure that interactions between multiple tiny modules remains consistently robust. Enforcement should be fully automated and an integral part of the OS.
Of course, this is only part of it. The other constraints (e.g., the use of plug-compatible links, strong typing, etc...) are known already. No message should be sent between objects unless first establishing that plugs are connected to compatible sockets, i.e., that they must be of the same type.
The most problematic aspect of computing, IMO, is that it is currently based on the algorithm. Problem is that algorithms wreak havoc in process timing and the end result is unreliability. The algorithm should not be the basis of computing. To ensure reliability, computing should be based on signal processing. Algorithms should only be part of application design, not process design. Just one man's opinion.
Let's say you have two qubits representing all superimposed numbers between 0 and 3 and you want to add 1 to all of them simultaneously. According to quantum computing experts, one can perform an operation on all the numbers at once. So after the addition operation the two qubits now have all the results between 1 and 3 (assuming the carry is thrown away). The question is, how does one get just one of the results back and be certain that it is the correct one?
The reason for not sharing information is obvious: under our economic system, the only source of income for almost everybody is individual labor. Scientific research is a very labor intensive activity and nobody is going to give their work away for nothing. Sure some scientists may share knowledge with others in the hope of winning a Nobel prize and make a name for themselves but that is a long shot.
Intellectual property laws exist only because we have a slavery system. Our livelihood depends on working for others so we can pay our taxes. The reason that we have to work for others is that 99% of people have been deprived of an inheritance in the wealth of the land. Income property is owned by a few and the state. The others are slaves. Artists, programmers and scientists depend on their work to make a living. Can we blame them? We all depend on our labor because we are all slaves. So now we are swimming in a ocean of laws and rules that take away our remaining liberties, one by one. And we are becoming more and more selfish.
But let's face it, if you cannot put a fence around it or put chains on it, it does not belong to you. Makes no difference whether it is ideas, writings, software, music or what have you. Once you've released it, like the air, it belongs to nobody and everybody. Scientists know that as soon as they reveal their secrets by sharing or even patenting them, there is nothing they can do to prevent other people from taking advantage of their labor. IP laws only serve to promote hateful competition and selfishness in a world that is becoming increasingly violent.
The internet and other communication technologies (e.g., file sharing systems) are the first major kinks in the armor of a sick system. As technology progresses, the system will eventually collapse. What will happen to a slave-based economy when robots and advanced artificial intelligences replace everybody, i. e., when human labor, knowledge and expertise become worthless?
And don't think for a minute this won't happen in your lifetime. The internet is the latest giant leap in human communication. Before that came mass telecommunication technologies and before that was the movable press. If history is any indication, we can expect a giant leap in technological progress and scientific knowledge. In fact, it is happening before our very eyes.
We should all demand a system where everybody is guaranteed income property, a piece of the pie, an estate if you will. There is plenty for everybody.
Communism confiscates all property and enslaves everybody. Capitalism gives property to a few and enslaves the rest. It's sad. The land has existed for billions of years before the first human beings appeared on the earth. Nobody has any legitimate ownership claim on the land. It should not be divided for a price. It should be an inheritance for us and our children and their children. It's the only way to guarantee freedom and a truly free market in a world where human labor is about to go the way of the dinosaurs.
I wonder if hydrogen power lines could one day replace the lossy electrical ones. Power generating companies could simply separate hydrogen from water through electrolysis and pump it to customers, kind of like the way natural gas is now distributed to homes and businesses. During slow demand hours, they could store hydrogen and release it later during peak hours.
Would this be safer and more efficient than convention power distribution? Any power engineers out there care to chime in on this?
Big Bang, Black Holes, Quantum Computing, etc...
on
Black Holes Disputed
·
· Score: -1, Troll
Big bang, time travel, black holes, quantum computing, etc... It's all Star Trek voodoo physics without any basis in reality, or even simple logic. We are being taken to the cleaners by a bunch of condescending, self-promoting pompous asses and con artists who have hijacked the science of physics.
We, the public, who pays for all this worthless crap, are the real bosses. We want good science for our money. We are tired of being treated like we are too stupid to figure out that we are being duped. We have gotten rid of condescending priesthoods in the past and we will do so again. One day, we will wake up from our stupor and wipe that smirk off their faces. The writing is on the wall.
The inevitable course of technological progress is the displacement of all workers. The internet is speeding up the rate of progress in science exponentially. HAL-like intelligent machines are just around the corner. Don't be so cocky in thinking that your expertise is indispensable for ever.
All economic systems (communism, capitalism, etc...) based on human labor and competition (read: slavery) are about to become obsolete. There is only one solution: an estate-based system. Divide the land, not for a price, but for an inheritance. Or perish! The writing is on the wall. Brave new world indeed.
It's a very depressing field right now. All the main ideas (mathematical logic, expert systems, neural nets, genetic algorithms, subsumption) have hit a wall.
I agree that the traditional AI community has reached a brick wall and it's very unlikely that any breakthrough in our understanding of intelligence will come from that sector. They've collected way too much useless baggage over the years.
However, interesting things are happening in the fields of computational neuroscience and neurobiology. The most exciting revelation that has surfaced in the last decade is that the brain is essentially a temporal processing machine. It seems that what matters is the temporal correlations between neural signals, not the manipulation of symbols (as we were led to believe by the now discredited AI crowd). Check out this interview with Jeff Hawkins. I think Jeff is onto something.
If you selfishly use patents laws to prevent other people from earning a living, don't complain when others use the same patent laws to put a monkey wrench in your works. In the meantime, the legal buzzards are laughing all the way to the bank.
I pray that I am wrong but I see a major war between the Western Christian world (mainly U.S. and Europe) and the Muslim world (especially the Arab world) in the not too distant future. The hatred between these two major groups have moved to unprecedented levels. I also see a complete destruction of the Muslim world. I don't think the people who did this realize the magnitude of the military and economic power of the Western world. Neither Jihad nor Mohammed will protect them from what's coming.
Sorry for sounding so pessimistic. I am normally an optimist but this is the two-by-four between the eyes that will bring the wrath and fury of a really pissed off giant.
Ask any of the professors you've been talking to whether this is what they meant. You'll get a resounding "yes".
I have no doubt that many physicists realize that nothing moves in spacetime. I quote several of them on my site. It does not take away from the fact that a huge number of physicists, including professors, believe that there is an actual evolution of bodies in spacetime along their geodesics. You feeble denials notwithstanding.
But all of this is really irrelevant to my argument. My argument is this, given that nothing can move in spacetime, how does one (Kip Thorne and Stephen Hawking come to mind) deduce from it that relativity does not forbid time travel. Heck, any idiot can see that relativity forbids time travel in any direction, either toward the past or the future. So don't use your obfuscations to hide the fact that some of the most celebrated physicists on the planet are dealing in snake oil.
The public is not as stupid as you so condescendingly assume. We don't like it when con artists (like Stephen Hawking and Kip Thorne), use our money to deceive us and tell us that we are too stupid to realize that we are being taken to the cleaners.
We, the public, refuse to be looked down on and, unless you (the physics priesthood) cease your shenanigans and your deceptions, we will rise up and wipe that smug superiority smile off your faces. We've gotten rid of condescending priesthoods in the past and we'll do so again in the future. You can rest assured.
Um, a "coordinate" is *defined* as a position with respect to an axis. One's coordinate, in space or time, is one's location when projected on to the appropriate space or time axis.
And what does that have to do with my stance that a temporal coordinate is invariant? Are you saying that a time coordinate can change. If you are, you are a crackpot and con artist.
Your entire premise seems to be based on the meaning of these two terms ("motion through time" and "coordinate") being garbled.
Your entire premise is tantamount to saying, "I believe that relativity does not forbid time travel and that it is possible in principle to go to one's past and visit one's great, great grandparents, but I don't really mean what you think I mean. Believe me, I've seen this sort of double talk a thousand times before. So don't think you can pass a wool over my eyes. And I am not the only one.
When they say an object "moves along a geodesic", it's shorthand for saying that the geodesic (and the object's worldline in spacetime) runs along the time axis of the graph (actually that the object's frame's time axis runs along the geodesic, but I digress). This is a linguistic short form; nothing more.
No it isn't. They use the same meaning for motion that everyone uses: a change in a coordinate within a coordinate system. How can you possibly guess what people mean when write to me since I have never shared my correspondence with you? I don't even know you.
It turns out that this is an extremely useful model of the universe, because it predicts the paths of objects in space and time more accurately than Newtonian gravity, and explains many other effects that had previously been mysterious.
It could not possibly be a model of the universe since one of its consequences is that there is no motion. It is a mere math trick that works because there is an inverse equivalence between acceleration and gravity: the principle of equivalence. Big deal though. The real intersting physics will come when someone explains gravity in terms of particles, their properties and their interactions. Anything else is either voodoo or simply following in the Ptolemaic tradition of coming up with contraptions to make predictions while having no clue as to what is really going on.
Saying that "time is an invariant" is like saying "position is an invariant" on this graph-paper sketch. It isn't - you can look at different positions in space and time on the graph. Thus, I find your statement confusing.
Not at all. When I say that time is invariant, I am talking about coordinate time, not the time axis that is graphed as an axis on a diagram. And the position of a particle is certainly not invariant since we observe moving particles all the time. But if one assumes that a particle has a temporal coordinate, then the particle immediately becomes motionless. This is the reason that nothing can move in spacetime, which you agreed to. There is no motion in time either toward the future or the past. The direction makes no difference. It's time travel either way.
My point (which you are trying so hard to obfuscate because it apparently offends your sensibilities and insults some of your idols) is that if nothing can move in spacetime, there is neither a time dimension nor time travel. An anybody (it makes no difference how famous or highly regarded that person is) who insists that the spacetime of relativity allows time travel in any direction either has no clue, or is a bona fide con artist.
I do not try to hide the fact that I am talking about people like Kip Thorne and Stephen Hawking. I value my freedom of speech and thought and I will not allow a bunch of pompous and condescending crackpots and charlatans in high places to do my thinking for me.
Nothing moves in spacetime, and nobody's saying it does.
You're kidding me? More than 3/4 of the emails I get from physicists (even professors) insist that there is motion in spacetime and that bodies are moving along their geodesics. They use this to support their notion that gravity is not a force because objects are following a straight path in spacetime.
Your statement about a "variable temporal coordinate" doesn't make much sense. All I'm doing when I "vary" the time coordinate is look at different points of the world-line, which is most certainly possible.
You can vary the time coodinate in your mind as much as you want but, in reality, a time coordinate cannot change. It is invariant. This is the reason that there is no time dimension, no spacetime and especially no time travel. Time is an *evolution* parameter, not a degree of freedom.
One of the most brilliant physists in the world is wrong and you are right.
You have no argument. You would rather attack the messenger than respond to the message. That's a cowardly tactic. But since you bring it up, there is always the possibility he's not as brilliant as you were led to believe. But what's the point of arguing with a cult follower?
As the parent described, what SF writers call "time travel" is not motion in time but rather a misnomer for a nearly closed loop in the object's geodesic.
It does not matter. There is no motion along geodesics. I realize that this is taught in many relativity classes but it's a fallacy nonetheless. IOW, geodesics do not exist. It's an abstraction.
Do the equations allow that an object's geodesic may loop around and nearly cross itself, creating an effect that would be perceived as "time travel" under the lay definition of travel?
The equations only describe a static (invariant) historical mapping of events. There is no motion at all in spacetime. One can talk about motion in space but not in spacetime. Advanced relativists like Fanchi and Howrwitz (e.g., see the latter's invariant tau formalism) know that worldline time (tau) does not change.
The idea that one can extrapolate closed time loop from extreme gravitational spacetime curvature is ludicrous. It's even more absurd when people talk about traveling in the loop to a time in the past. Yet, this is what Kip Thorne and Hawking claim is possible.
Spacetime is an abstract math construct used for making predictions about the motion of a body in space and the internal speed of clocks. It does not represent anything in nature. If it did there would be no motion. Physicists have no idea why the construct appears curved in the presence of mass when they map distance and clock measurements on graph paper. Here is what Dr. Robert Geroch has to say about motion in spacetime in his book "Relativity from A to B (page 20):
"There is no dynamics within space-time itself: nothing ever moves therein; nothing happens; nothing changes."
So there you have it. In conclusion, it is fallacy that time changes. tau (worldline time) is invariant regardless of what you think your clock says. Clocks change and from that we obtain time intervals.
Possibly I have misinterpreted the document, but this seems unlikely, as it makes it abundantly clear that time travel involves "motion" of spacetime, which "is impossible".
Certainly but you misinterpreted my argument. Why is there no motion in spacetime? Because for something to move in spacetime (or in time) it would need to have a variable temporal coordinate. This is impossible because a changing time coordinate is self-referential: it takes time to change, by definition.
And it is not simply a matter of not being able to move backward in time. There is no motion at all in time, forward or backward. Therefore there is no time dimension. And if there is no time dimension, there is no time travel either, closed time-like loop notwithstanding.
Personally, I'd recommend a university course, if you can find a good professor and a relatively intelligent class. If you've studied a foreign language, that will be very helpful, especially with the grammar.
Arne, thanks for the advice and your help in transliterating from NT Greek. I really appreciate your informed posts.
Technically, the word transliterated as "'autou" is ambiguous.
Well, it seems like I may be back to my original interpretation.
However, it's basically clear from the context that the referent is in fact the beast (so it's neuter in Greek).
I am not so sure about that. Logically speaking, when one is asked to calculate a result, the result is not given. What would be the point?
Having said that, I envy you people's grasp of the NT Greek language. I find it to be a fascinating field, not unlike encryption but much more interesting because it deals with history. Thanks to all of you for your input.
P.S. Which of the following alternatives would you guys recommend as the best way to become reasonably proficient in ancient Greek in a short time? A university course or self-study using a good text book?
The original (or, as close to the original as i have available, if you're of that line of htinking) Greek is clear that the number being calculated is associated with the calculatee, not the calculator.
Thanks for that informative post. If I understand what you wrote correctly, the part translated "and his number is..." in English should have been "and it is..."
18. hic sapientia est qui habet intellectum conputet numerum bestiae numerus enim hominis est et numerus eius est sescenti sexaginta sex
It seems to me that "sescenti sexaginta sex" refers to the beast here.
The question is, who does "et numerus eius" refer to? And what happened to the original punctuation marks? I am pretty sure there were punctuation marks in the original Greek.
Slashdot Mirror
This problem is too big to solve in one big step.
The incremental approach is precisely why we don't yet have a HAL-like intelligent machine. That's the approach that's been used up to now by the GOFAI community and it has failed miserably. If the goal of an AI researcher is to understand human cognition, the problem is indeed too big. The interconnectedness of human cognition is so astronomically complex as to be intractable to formal solutions. This problem is too big for any approach, incremental or otherwise. Therefore the goal of the sensible AI researcher is not to develop a theory of cognition, but to discover the fundamental principles that govern the emergence of intelligence. Let's get the damn thing to learn first. We can worry about what it's thinking later. We need an overarching theory of the brain. We don't need limited, isolated bits of cognition.
You're right. Brooks has created a few glorified toys and made a name for himself. MIT's Technology Review refers to him as "The Lord of the Robots". It's all PR. The AI community has failed on its promise to create a human-level artificial intelligence and they've been at it for fifty years! So what do we do? We throw more money at them. Makes sense. Not! We need new ideas and new blood in AI research. The tax-paying public should not be forced to reward failure.
What is analog about a spike fired by a neuron, pray tell? What is analog about DNA? Tilden should stick to his toys, IMO, because that's all he'll ever build. In the meantime, real AI researchers will conduct experiments in temporal spiking networks.
Sure, you've got to start with reliable components, but you have to combine them in just the right way, too.
First off, we should learn a lesson from biology. The bee, for example, has about a million interconnected neurons. Yet the bee's highly sophisticated behavior is extremely robust and efficient. How does nature do it? The answer has to do with parallelism and expectations.
1. Parallel processing insures that signals are not delayed, i.e., their relative arrival times are guaranteed to be consistent.
2. Expectations are assumptions that neurons make about the relative order of signal arrival times.
We can emulate the robustness of nature by first realizing that computing is really a genus of a species known as signal processing. We can obtain very high reliability by emulating the parallelism of nature and enforcing a program's expectations about the temporal order of messages: no signal/message should arrive before its time. The use of stringent timing constraints will ensure that interactions between multiple tiny modules remains consistently robust. Enforcement should be fully automated and an integral part of the OS.
Of course, this is only part of it. The other constraints (e.g., the use of plug-compatible links, strong typing, etc...) are known already. No message should be sent between objects unless first establishing that plugs are connected to compatible sockets, i.e., that they must be of the same type.
The most problematic aspect of computing, IMO, is that it is currently based on the algorithm. Problem is that algorithms wreak havoc in process timing and the end result is unreliability. The algorithm should not be the basis of computing. To ensure reliability, computing should be based on signal processing. Algorithms should only be part of application design, not process design. Just one man's opinion.
Let's say you have two qubits representing all superimposed numbers between 0 and 3 and you want to add 1 to all of them simultaneously. According to quantum computing experts, one can perform an operation on all the numbers at once. So after the addition operation the two qubits now have all the results between 1 and 3 (assuming the carry is thrown away). The question is, how does one get just one of the results back and be certain that it is the correct one?
I've said this before but it bears repeating.
The reason for not sharing information is obvious: under our economic system, the only source of income for almost everybody is individual labor. Scientific research is a very labor intensive activity and nobody is going to give their work away for nothing. Sure some scientists may share knowledge with others in the hope of winning a Nobel prize and make a name for themselves but that is a long shot.
Intellectual property laws exist only because we have a slavery system. Our livelihood depends on working for others so we can pay our taxes. The reason that we have to work for others is that 99% of people have been deprived of an inheritance in the wealth of the land. Income property is owned by a few and the state. The others are slaves. Artists, programmers and scientists depend on their work to make a living. Can we blame them? We all depend on our labor because we are all slaves. So now we are swimming in a ocean of laws and rules that take away our remaining liberties, one by one. And we are becoming more and more selfish.
But let's face it, if you cannot put a fence around it or put chains on it, it does not belong to you. Makes no difference whether it is ideas, writings, software, music or what have you. Once you've released it, like the air, it belongs to nobody and everybody. Scientists know that as soon as they reveal their secrets by sharing or even patenting them, there is nothing they can do to prevent other people from taking advantage of their labor. IP laws only serve to promote hateful competition and selfishness in a world that is becoming increasingly violent.
The internet and other communication technologies (e.g., file sharing systems) are the first major kinks in the armor of a sick system. As technology progresses, the system will eventually collapse. What will happen to a slave-based economy when robots and advanced artificial intelligences replace everybody, i. e., when human labor, knowledge and expertise become worthless?
And don't think for a minute this won't happen in your lifetime. The internet is the latest giant leap in human communication. Before that came mass telecommunication technologies and before that was the movable press. If history is any indication, we can expect a giant leap in technological progress and scientific knowledge. In fact, it is happening before our very eyes.
We should all demand a system where everybody is guaranteed income property, a piece of the pie, an estate if you will. There is plenty for everybody.
Communism confiscates all property and enslaves everybody. Capitalism gives property to a few and enslaves the rest. It's sad. The land has existed for billions of years before the first human beings appeared on the earth. Nobody has any legitimate ownership claim on the land. It should not be divided for a price. It should be an inheritance for us and our children and their children. It's the only way to guarantee freedom and a truly free market in a world where human labor is about to go the way of the dinosaurs.
Demand liberty! Nothing less.
-----
At least for cars anyway. Check out this MSNBC news article
I wonder if hydrogen power lines could one day replace the lossy electrical ones. Power generating companies could simply separate hydrogen from water through electrolysis and pump it to customers, kind of like the way natural gas is now distributed to homes and businesses. During slow demand hours, they could store hydrogen and release it later during peak hours.
Would this be safer and more efficient than convention power distribution? Any power engineers out there care to chime in on this?
Big bang, time travel, black holes, quantum computing, etc... It's all Star Trek voodoo physics without any basis in reality, or even simple logic. We are being taken to the cleaners by a bunch of condescending, self-promoting pompous asses and con artists who have hijacked the science of physics.
We, the public, who pays for all this worthless crap, are the real bosses. We want good science for our money. We are tired of being treated like we are too stupid to figure out that we are being duped. We have gotten rid of condescending priesthoods in the past and we will do so again. One day, we will wake up from our stupor and wipe that smirk off their faces. The writing is on the wall.
The inevitable course of technological progress is the displacement of all workers. The internet is speeding up the rate of progress in science exponentially. HAL-like intelligent machines are just around the corner. Don't be so cocky in thinking that your expertise is indispensable for ever.
All economic systems (communism, capitalism, etc...) based on human labor and competition (read: slavery) are about to become obsolete. There is only one solution: an estate-based system. Divide the land, not for a price, but for an inheritance. Or perish! The writing is on the wall. Brave new world indeed.
It's a very depressing field right now. All the main ideas (mathematical logic, expert systems, neural nets, genetic algorithms, subsumption) have hit a wall.
I agree that the traditional AI community has reached a brick wall and it's very unlikely that any breakthrough in our understanding of intelligence will come from that sector. They've collected way too much useless baggage over the years.
However, interesting things are happening in the fields of computational neuroscience and neurobiology. The most exciting revelation that has surfaced in the last decade is that the brain is essentially a temporal processing machine. It seems that what matters is the temporal correlations between neural signals, not the manipulation of symbols (as we were led to believe by the now discredited AI crowd). Check out this interview with Jeff Hawkins. I think Jeff is onto something.
If you selfishly use patents laws to prevent other people from earning a living, don't complain when others use the same patent laws to put a monkey wrench in your works. In the meantime, the legal buzzards are laughing all the way to the bank.
I pray that I am wrong but I see a major war between the Western Christian world (mainly U.S. and Europe) and the Muslim world (especially the Arab world) in the not too distant future. The hatred between these two major groups have moved to unprecedented levels. I also see a complete destruction of the Muslim world. I don't think the people who did this realize the magnitude of the military and economic power of the Western world. Neither Jihad nor Mohammed will protect them from what's coming.
Sorry for sounding so pessimistic. I am normally an optimist but this is the two-by-four between the eyes that will bring the wrath and fury of a really pissed off giant.
Ask any of the professors you've been talking to whether this is what they meant. You'll get a resounding "yes".
I have no doubt that many physicists realize that nothing moves in spacetime. I quote several of them on my site. It does not take away from the fact that a huge number of physicists, including professors, believe that there is an actual evolution of bodies in spacetime along their geodesics. You feeble denials notwithstanding.
But all of this is really irrelevant to my argument. My argument is this, given that nothing can move in spacetime, how does one (Kip Thorne and Stephen Hawking come to mind) deduce from it that relativity does not forbid time travel. Heck, any idiot can see that relativity forbids time travel in any direction, either toward the past or the future. So don't use your obfuscations to hide the fact that some of the most celebrated physicists on the planet are dealing in snake oil.
The public is not as stupid as you so condescendingly assume. We don't like it when con artists (like Stephen Hawking and Kip Thorne), use our money to deceive us and tell us that we are too stupid to realize that we are being taken to the cleaners.
We, the public, refuse to be looked down on and, unless you (the physics priesthood) cease your shenanigans and your deceptions, we will rise up and wipe that smug superiority smile off your faces. We've gotten rid of condescending priesthoods in the past and we'll do so again in the future. You can rest assured.
Um, a "coordinate" is *defined* as a position with respect to an axis. One's coordinate, in space or time, is one's location when projected on to the appropriate space or time axis.
And what does that have to do with my stance that a temporal coordinate is invariant? Are you saying that a time coordinate can change. If you are, you are a crackpot and con artist.
Your entire premise seems to be based on the meaning of these two terms ("motion through time" and "coordinate") being garbled.
Your entire premise is tantamount to saying, "I believe that relativity does not forbid time travel and that it is possible in principle to go to one's past and visit one's great, great grandparents, but I don't really mean what you think I mean. Believe me, I've seen this sort of double talk a thousand times before. So don't think you can pass a wool over my eyes. And I am not the only one.
When they say an object "moves along a geodesic", it's shorthand for saying that the geodesic (and the object's worldline in spacetime) runs along the time axis of the graph (actually that the object's frame's time axis runs along the geodesic, but I digress). This is a linguistic short form; nothing more.
No it isn't. They use the same meaning for motion that everyone uses: a change in a coordinate within a coordinate system. How can you possibly guess what people mean when write to me since I have never shared my correspondence with you? I don't even know you.
It turns out that this is an extremely useful model of the universe, because it predicts the paths of objects in space and time more accurately than Newtonian gravity, and explains many other effects that had previously been mysterious.
It could not possibly be a model of the universe since one of its consequences is that there is no motion. It is a mere math trick that works because there is an inverse equivalence between acceleration and gravity: the principle of equivalence. Big deal though. The real intersting physics will come when someone explains gravity in terms of particles, their properties and their interactions. Anything else is either voodoo or simply following in the Ptolemaic tradition of coming up with contraptions to make predictions while having no clue as to what is really going on.
Saying that "time is an invariant" is like saying "position is an invariant" on this graph-paper sketch. It isn't - you can look at different positions in space and time on the graph. Thus, I find your statement confusing.
Not at all. When I say that time is invariant, I am talking about coordinate time, not the time axis that is graphed as an axis on a diagram. And the position of a particle is certainly not invariant since we observe moving particles all the time. But if one assumes that a particle has a temporal coordinate, then the particle immediately becomes motionless. This is the reason that nothing can move in spacetime, which you agreed to. There is no motion in time either toward the future or the past. The direction makes no difference. It's time travel either way.
My point (which you are trying so hard to obfuscate because it apparently offends your sensibilities and insults some of your idols) is that if nothing can move in spacetime, there is neither a time dimension nor time travel. An anybody (it makes no difference how famous or highly regarded that person is) who insists that the spacetime of relativity allows time travel in any direction either has no clue, or is a bona fide con artist.
I do not try to hide the fact that I am talking about people like Kip Thorne and Stephen Hawking. I value my freedom of speech and thought and I will not allow a bunch of pompous and condescending crackpots and charlatans in high places to do my thinking for me.
Nothing moves in spacetime, and nobody's saying it does.
You're kidding me? More than 3/4 of the emails I get from physicists (even professors) insist that there is motion in spacetime and that bodies are moving along their geodesics. They use this to support their notion that gravity is not a force because objects are following a straight path in spacetime.
Your statement about a "variable temporal coordinate" doesn't make much sense. All I'm doing when I "vary" the time coordinate is look at different points of the world-line, which is most certainly possible.
You can vary the time coodinate in your mind as much as you want but, in reality, a time coordinate cannot change. It is invariant. This is the reason that there is no time dimension, no spacetime and especially no time travel. Time is an *evolution* parameter, not a degree of freedom.
One of the most brilliant physists in the world is wrong and you are right.
You have no argument. You would rather attack the messenger than respond to the message. That's a cowardly tactic. But since you bring it up, there is always the possibility he's not as brilliant as you were led to believe. But what's the point of arguing with a cult follower?
As the parent described, what SF writers call "time travel" is not motion in time but rather a misnomer for a nearly closed loop in the object's geodesic.
It does not matter. There is no motion along geodesics. I realize that this is taught in many relativity classes but it's a fallacy nonetheless. IOW, geodesics do not exist. It's an abstraction.
Do the equations allow that an object's geodesic may loop around and nearly cross itself, creating an effect that would be perceived as "time travel" under the lay definition of travel?
The equations only describe a static (invariant) historical mapping of events. There is no motion at all in spacetime. One can talk about motion in space but not in spacetime. Advanced relativists like Fanchi and Howrwitz (e.g., see the latter's invariant tau formalism) know that worldline time (tau) does not change.
The idea that one can extrapolate closed time loop from extreme gravitational spacetime curvature is ludicrous. It's even more absurd when people talk about traveling in the loop to a time in the past. Yet, this is what Kip Thorne and Hawking claim is possible.
Spacetime is an abstract math construct used for making predictions about the motion of a body in space and the internal speed of clocks. It does not represent anything in nature. If it did there would be no motion. Physicists have no idea why the construct appears curved in the presence of mass when they map distance and clock measurements on graph paper. Here is what Dr. Robert Geroch has to say about motion in spacetime in his book "Relativity from A to B (page 20):
"There is no dynamics within space-time itself: nothing ever moves therein; nothing happens; nothing changes."
So there you have it. In conclusion, it is fallacy that time changes. tau (worldline time) is invariant regardless of what you think your clock says. Clocks change and from that we obtain time intervals.
Possibly I have misinterpreted the document, but this seems unlikely, as it makes it abundantly clear that time travel involves "motion" of spacetime, which "is impossible".
Certainly but you misinterpreted my argument. Why is there no motion in spacetime? Because for something to move in spacetime (or in time) it would need to have a variable temporal coordinate. This is impossible because a changing time coordinate is self-referential: it takes time to change, by definition.
And it is not simply a matter of not being able to move backward in time. There is no motion at all in time, forward or backward. Therefore there is no time dimension. And if there is no time dimension, there is no time travel either, closed time-like loop notwithstanding.
If you think lichen spots are cool, check out the trees of Mars.
Personally, I'd recommend a university course, if you can find a good professor and a relatively intelligent class. If you've studied a foreign language, that will be very helpful, especially with the grammar.
Arne, thanks for the advice and your help in transliterating from NT Greek. I really appreciate your informed posts.
Technically, the word transliterated as "'autou" is ambiguous.
Well, it seems like I may be back to my original interpretation.
However, it's basically clear from the context that the referent is in fact the beast (so it's neuter in Greek).
I am not so sure about that. Logically speaking, when one is asked to calculate a result, the result is not given. What would be the point?
Having said that, I envy you people's grasp of the NT Greek language. I find it to be a fascinating field, not unlike encryption but much more interesting because it deals with history. Thanks to all of you for your input.
P.S. Which of the following alternatives would you guys recommend as the best way to become reasonably proficient in ancient Greek in a short time? A university course or self-study using a good text book?
The original (or, as close to the original as i have available, if you're of that line of htinking) Greek is clear that the number being calculated is associated with the calculatee, not the calculator.
Thanks for that informative post. If I understand what you wrote correctly, the part translated "and his number is..." in English should have been "and it is..."
Don't you mean original Aramaeic?
No. AFAIK, the book of Revelations was written in Greek on the island of Patmos.
18. hic sapientia est qui habet intellectum conputet numerum bestiae numerus enim hominis est et numerus eius est sescenti sexaginta sex
It seems to me that "sescenti sexaginta sex" refers to the beast here.
The question is, who does "et numerus eius" refer to? And what happened to the original punctuation marks? I am pretty sure there were punctuation marks in the original Greek.