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| Tags: allien, genius, learn, wants, who |
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#81
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On May 15, 7:04*pm, JanPB wrote:
On May 14, 10:08*pm, Koobee Wublee wrote: On May 14, 7:10 am, Mike wrote: On May 13, 5:46 pm, Koobee Wublee wrote: The spacetime described by the Schwarzschild metric only applied to the spherically symmetric polar coordinate. *You are welcome to transform to another coordinate system with a different metric. No, the Schwarzschild metric IS the metric. There is no such thing as Schwarzschild metric in a coordinate system with a metric. Mathematically, you are just wrong. *For example, describing flat spacetime using the linear rectangular (Euclidean) and using the spherically symmetric polar coordinate systems require you to supply different metric for each choice of coordinate system. *shrug No, it's the same metric in both cases, e.g. in the plane the following are equal: * * dx^2 + dy^2 and: * * dr^2 + r^2 dtheta^2 ...where x = r cos(theta) and y = r sin(theta) (polar coordinates). The above are two different coordinate decompositions of the same metric. To see that they are equal, just evaluate them on an arbitrary vector and see you get the same value in both cases. This is where KW gets the small chicken bone stuck in his throat, completely unable to swallow the distinction between a vector or tensor and its coordinate decompositions. To him, if you have a different component representation, you're talking about a physically different thing, and he pretends to sniff that it is "mathematically so". For example, consider vector v defined in Cartesian coordinates like this: * * v is situated at point (1,1), * * v = (1,2) Then, applying ds^2 = dx^2 + dy^2: * * ds^2(v) = v.v = dx(v) * dx(v) + dy(v) * dy(v) = 1^2 + 2^2 = 5 Now calculate using the polar representation of ds^2: * * v is situated at (sqrt(2), pi/4), * * v = (3/sqrt(2), -1/2) Then, applying ds^2 = dr^2 + r^2 dtheta^2: * * ds^2(v) = v.v = dr(v) * dr(v) + (sqrt(2))^2 * dtheta(v) * dtheta(v) = * * * * * * = (3/sqrt(2))^2 + 2 * (-1/2)^2 = * * * * * * = 9/2 + 2 * 1/4 = * * * * * * = 9/2 + 1/2 = 10/2 = 5 Same result! Yout hink that's an accident? :-) You'd obtain the corresponding same results with any vector. It must be so because both expressions for ds^2 are equal. Same thing with Schwarzschild, etc. The term "metric" as used by everyone refers to that mapping that takes tangent vectors (like v) to their squared lengths (like v.v). That mapping is coordinate-INdependent. OTOH its _coordinate representation_ of course depends on coordinates (by definition). But dx^2+dy^2 and dr^2 + r^2 dtheta^2 are two different coordinate representations of the same metric (the same mapping taking v to v.v, or equivalently, a mapping taking vector pairs v,w to v.w - that's what metric _is_). -- Jan Bielawski |
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#82
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On May 15, 5:04 pm, JanPB wrote:
On May 14, 10:08 pm, Koobee Wublee wrote: Mathematically, you are just wrong. For example, describing flat spacetime using the linear rectangular (Euclidean) and using the spherically symmetric polar coordinate systems require you to supply different metric for each choice of coordinate system. shrug No, it's the same metric in both cases, e.g. in the plane the following are equal: dx^2 + dy^2 and: dr^2 + r^2 dtheta^2 ...where x = r cos(theta) and y = r sin(theta) (polar coordinates). The above are two different coordinate decompositions of the same metric. To see that they are equal, just evaluate them on an arbitrary vector and see you get the same value in both cases. You are making the same mistake again. What you refer to is the geometry itself not the metric. The equations above represent the same geometry, yes. They are equivalent. However, the coordinates are different, and the metrics are different. The metric cannot adequately describe the geometry despite your voodoo conjectures of dot products, and the coordinates itself cannot adequately describe the geometry. It takes both well specified coordinate systems and the metrics to fully describe the geometries. shrug We cannot go on without you understand my point of view, and I have understood yours and pointed the errors in your logic. If you are not malicious as Eric Gisse is, you need to understand my point of view. shrug |
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#83
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On May 15, 10:24*pm, Koobee Wublee wrote:
[snip] How can you be so confident in your assertions that the math supports you when nobody else agrees with you along with your inability to actually calculate anything? |
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#84
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On May 16, 1:24*am, Koobee Wublee wrote:
On May 15, 5:04 pm, JanPB wrote: On May 14, 10:08 pm, Koobee Wublee wrote: Mathematically, you are just wrong. *For example, describing flat spacetime using the linear rectangular (Euclidean) and using the spherically symmetric polar coordinate systems require you to supply different metric for each choice of coordinate system. *shrug No, it's the same metric in both cases, e.g. in the plane the following are equal: * * dx^2 + dy^2 and: * * dr^2 + r^2 dtheta^2 ...where x = r cos(theta) and y = r sin(theta) (polar coordinates). The above are two different coordinate decompositions of the same metric. To see that they are equal, just evaluate them on an arbitrary vector and see you get the same value in both cases. You are making the same mistake again. *What you refer to is the geometry itself not the metric. Then you are suffering from a basic misalignment on terminology. The metric *is* the geometry. That's the point. *The equations above represent the same geometry, yes. *They are equivalent. *However, the coordinates are different, and the metrics are different. *The metric cannot adequately describe the geometry despite your voodoo conjectures of dot products, and the coordinates itself cannot adequately describe the geometry. *It takes both well specified coordinate systems and the metrics to fully describe the geometries. *shrug We cannot go on without you understand my point of view, and I have understood yours and pointed the errors in your logic. *If you are not malicious as Eric Gisse is, you need to understand my point of view. shrug |
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#85
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On May 16, 8:45*am, PD wrote:
On May 16, 1:24*am, Koobee Wublee wrote: On May 15, 5:04 pm, JanPB wrote: On May 14, 10:08 pm, Koobee Wublee wrote: Mathematically, you are just wrong. *For example, describing flat spacetime using the linear rectangular (Euclidean) and using the spherically symmetric polar coordinate systems require you to supply different metric for each choice of coordinate system. *shrug No, it's the same metric in both cases, e.g. in the plane the following are equal: * * dx^2 + dy^2 and: * * dr^2 + r^2 dtheta^2 ...where x = r cos(theta) and y = r sin(theta) (polar coordinates).. The above are two different coordinate decompositions of the same metric. To see that they are equal, just evaluate them on an arbitrary vector and see you get the same value in both cases. You are making the same mistake again. *What you refer to is the geometry itself not the metric. Then you are suffering from a basic misalignment on terminology. The metric *is* the geometry. That's the point. You are wrong once more along with your wannabees friends. You confuse metrics with metric spaces. A metric is just a function that defines distance between elements of a set. A metric space is a set WITH a metric defined. A metric induces a topology on a set but it may not be sufficient to generate a topology. Listen you morons: KW is right, you have no freaken idea of what you are talking about. My suspicion that you are just cranks has been confirmed many times. Hey stupidos, I can have a Manhattan metric in Euclidean space. But given just the Manhattan metric, how would anyone know the geometry is Euclidean? Hey stupid, I tell you my metric is abs(x1-x2)+abs(y1-y2) what tha fok do you know from that? Pther than how I measure distance. The metric, especially a strange one like the ones imagined in GR, does not tell you much about the topology. OFTEN THE UNDERLINE TOPOLOGY IS ASSUMED, AND THIS AMOUNTS TO SCIENTIFIC CON. Mike *The equations above represent the same geometry, yes. *They are equivalent. *However, the coordinates are different, and the metrics are different. *The metric cannot adequately describe the geometry despite your voodoo conjectures of dot products, and the coordinates itself cannot adequately describe the geometry. *It takes both well specified coordinate systems and the metrics to fully describe the geometries. *shrug We cannot go on without you understand my point of view, and I have understood yours and pointed the errors in your logic. *If you are not malicious as Eric Gisse is, you need to understand my point of view. shrug- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text - |
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#86
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On May 16, 6:10*am, Mike wrote:
[snip] Wow, the first person who actually agrees with ol' kooby is an idiot. Didn't see that one coming. |
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#87
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On May 16, 10:40*am, Eric Gisse wrote:
On May 16, 6:10*am, Mike wrote: [snip] Wow, the first person who actually agrees with ol' kooby is an idiot. Didn't see that one coming. YOu stupid dropout. What do you know about metric spaces when you think that a = GM.r^2 is an Euler ODE? http://groups.google.gr/group/sci.ph...b?dmode=source How do you have the nerve to discuss such issues when you javen't gone past high school algebra? NOw, send email to your friend DIrt to come and throw his Dirt. Cry stupid to Dirt, cry. "Dirt, Dirt please wake up, please, wake up, come and post, Mike is again showing that ODE thing... Please Dirt, when I come to Belgium I buy you a six pack... please Dirt. You can do to me anything you want...." Moron.... Mike |
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#88
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On May 16, 9:10*am, Mike wrote:
On May 16, 8:45*am, PD wrote: On May 16, 1:24*am, Koobee Wublee wrote: On May 15, 5:04 pm, JanPB wrote: On May 14, 10:08 pm, Koobee Wublee wrote: Mathematically, you are just wrong. *For example, describing flat spacetime using the linear rectangular (Euclidean) and using the spherically symmetric polar coordinate systems require you to supply different metric for each choice of coordinate system. *shrug No, it's the same metric in both cases, e.g. in the plane the following are equal: * * dx^2 + dy^2 and: * * dr^2 + r^2 dtheta^2 ...where x = r cos(theta) and y = r sin(theta) (polar coordinates). The above are two different coordinate decompositions of the same metric. To see that they are equal, just evaluate them on an arbitrary vector and see you get the same value in both cases. You are making the same mistake again. *What you refer to is the geometry itself not the metric. Then you are suffering from a basic misalignment on terminology. The metric *is* the geometry. That's the point. You are wrong once more along with your wannabees friends. You confuse metrics with metric spaces. A metric is just a function that defines distance between elements of a set. A metric space is a set WITH a metric defined. A metric induces a topology on a set but it may not be sufficient to generate a topology. But the topology doesn't tell you (much of) anything about the *shape* of the space as is relevant for physics, where the relevant feeds from shape pertain to *interval* and, for a particular observer, perhaps space and time coordinates, and these have everything to do with the metric. Moreover, the notion of a geodesic, which is a path of extremal measure between two points in the manifold, has everything to do with the metric. Likewise, acceleration due to non-gravitational forces is defined in terms of the metric. Listen you morons: KW is right, you have no freaken idea of what you are talking about. My suspicion that you are just cranks has been confirmed many times. Hey stupidos, I can have a Manhattan metric in Euclidean space. But given just the Manhattan metric, how would anyone know the geometry is Euclidean? Because it is a constant metric with a zero curvature. That's what flat means. Hey stupid, I tell you my metric is abs(x1-x2)+abs(y1-y2) what tha fok do you know from that? Pther than how I measure distance. The metric, especially a strange one like the ones imagined in GR, does not tell you much about the topology. OFTEN THE UNDERLINE TOPOLOGY IS ASSUMED, AND THIS AMOUNTS TO SCIENTIFIC CON. Mike *The equations above represent the same geometry, yes. *They are equivalent. *However, the coordinates are different, and the metrics are different. *The metric cannot adequately describe the geometry despite your voodoo conjectures of dot products, and the coordinates itself cannot adequately describe the geometry. *It takes both well specified coordinate systems and the metrics to fully describe the geometries. *shrug We cannot go on without you understand my point of view, and I have understood yours and pointed the errors in your logic. *If you are not malicious as Eric Gisse is, you need to understand my point of view. shrug- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text - |
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#89
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On May 16, 10:53*am, PD wrote:
On May 16, 9:10*am, Mike wrote: On May 16, 8:45*am, PD wrote: On May 16, 1:24*am, Koobee Wublee wrote: On May 15, 5:04 pm, JanPB wrote: On May 14, 10:08 pm, Koobee Wublee wrote: Mathematically, you are just wrong. *For example, describing flat spacetime using the linear rectangular (Euclidean) and using the spherically symmetric polar coordinate systems require you to supply different metric for each choice of coordinate system. *shrug No, it's the same metric in both cases, e.g. in the plane the following are equal: * * dx^2 + dy^2 and: * * dr^2 + r^2 dtheta^2 ...where x = r cos(theta) and y = r sin(theta) (polar coordinates). The above are two different coordinate decompositions of the same metric. To see that they are equal, just evaluate them on an arbitrary vector and see you get the same value in both cases. You are making the same mistake again. *What you refer to is the geometry itself not the metric. Then you are suffering from a basic misalignment on terminology. The metric *is* the geometry. That's the point. You are wrong once more along with your wannabees friends. You confuse metrics with metric spaces. A metric is just a function that defines distance between elements of a set. A metric space is a set WITH a metric defined. A metric induces a topology on a set but it may not be sufficient to generate a topology. But the topology doesn't tell you (much of) anything about the *shape* of the space as is relevant for physics, where the relevant feeds from shape pertain to *interval* and, for a particular observer, perhaps space and time coordinates, and these have everything to do with the metric. Moreover, the notion of a geodesic, which is a path of extremal measure between two points in the manifold, has everything to do with the metric. Likewise, acceleration due to non-gravitational forces is defined in terms of the metric. Listen you morons: KW is right, you have no freaken idea of what you are talking about. My suspicion that you are just cranks has been confirmed many times. Hey stupidos, I can have a Manhattan metric in Euclidean space. But given just the Manhattan metric, how would anyone know the geometry is Euclidean? Because it is a constant metric with a zero curvature. That's what flat means. N, a metric by itself tells you nothing about the UNDERLINE geometry, what KW I think calls a coordinate system. I can use that metric in any geometry, flat or non-flat. A metric space is a set with a metric defined. Mike Hey stupid, I tell you my metric is abs(x1-x2)+abs(y1-y2) what tha fok do you know from that? Pther than how I measure distance. The metric, especially a strange one like the ones imagined in GR, does not tell you much about the topology. OFTEN THE UNDERLINE TOPOLOGY IS ASSUMED, AND THIS AMOUNTS TO SCIENTIFIC CON. Mike *The equations above represent the same geometry, yes. *They are equivalent. *However, the coordinates are different, and the metrics are different. *The metric cannot adequately describe the geometry despite your voodoo conjectures of dot products, and the coordinates itself cannot adequately describe the geometry. *It takes both well specified coordinate systems and the metrics to fully describe the geometries. *shrug We cannot go on without you understand my point of view, and I have understood yours and pointed the errors in your logic. *If you are not malicious as Eric Gisse is, you need to understand my point of view. shrug- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text - |
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#90
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On May 16, 6:51*am, Mike wrote:
On May 16, 10:40*am, Eric Gisse wrote: On May 16, 6:10*am, Mike wrote: [snip] Wow, the first person who actually agrees with ol' kooby is an idiot. Didn't see that one coming. YOu stupid dropout. What do you know about metric spaces when you think that a = GM.r^2 is an Euler ODE? http://groups.google.gr/group/sci.ph...g/01b8793b2b1f... How do you have the nerve to discuss such issues when you javen't gone past high school algebra? NOw, send email to your friend DIrt to come and throw his Dirt. Cry stupid to Dirt, cry. "Dirt, Dirt please wake up, please, wake up, come and post, Mike is again showing that ODE thing... Please Dirt, when I come to Belgium I buy you a six pack... please Dirt. You can do to me anything you want...." Moron.... Mike I wonder what's wrong with your head that makes you think writing stuff like this is a good idea. |
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