View Single Post
  #85  
Old May 16th 08 posted to sci.physics.relativity
Mike
external usenet poster
 
Posts: 3,599
Default I have an Allien genius who wants to learn GR

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 -


Ads
 

Symbian Cell Phone Software - Mortgages - Mortgage Calculator - Teen Chat - Php Script