Ever use cylindrical coordinates?

Brent


On 9/5/2024 2:07 PM, Alan Grayson wrote:
Since the metric tensor is defined on the*flat *tangent space, will its matrix representation always be diagonal? TY, AG

On Thursday, September 5, 2024 at 12:35:03 PM UTC-6 Brent Meeker wrote:

    If  you change coordinate systems the vectors and tensors
    transform in such a way that the physics is unchanged.  That's the
    defining property of vectors and tensors and why they are not just
    the arrays used to represent them.

    Brent



    On 9/4/2024 10:42 PM, Alan Grayson wrote:
    How is the foregoing consistent with the statement that tensors
    are independent of coordinate systems? TY, AG

    On Wednesday, September 4, 2024 at 10:39:33 PM UTC-6 Alan Grayson
    wrote:

        No; you never posted any page numbers in your reference. Had
        you done that, I would have immediately studied your specific
        reference. But I was about to post something like what you
        wrote; namely, that *solving* for the metric tensor *MEANS*
        solving for the 16 components defining its function, given a
        stress-energy tensor and a coordinate system. The form of the
        components must depend on the coordinates. And given a
        coordinate system, the components will vary depending on
        location in spacetime, and this is what's meant by the
        "metric tensor field". I thought the "field" refers to a
        *unique* *real numbe*r at each point in spacetime, but it
        must refer to the components of the matrix representing the
        tensor. Wiki's definition seems misleading since it states
        that the metric tensor is a bilinear function of two vectors
        on the tangent plane. Those vectors are its arguments, but
        sort-of misleading. Is there anything in the foregoing that I
        got wrong? AG
        On Wednesday, September 4, 2024 at 8:09:07 PM UTC-6 Brent
        Meeker wrote:

            The metric field is the set of metric tensors, one at
            each point.  It's not some vector lengths.

            When are you gonna read "Relativity DeMystifie".  I told
            you the page numbers and you can look up more in the index.

            Brent



            On 9/4/2024 5:59 PM, Alan Grayson wrote:
            But my point is therefore that the metric tensor field
            is ambiguous !

            On Wednesday, September 4, 2024 at 6:40:38 PM UTC-6
            Brent Meeker wrote:

                It explains this "...and yields *different *real
                values for most different pairs."

                Brent



                On 9/4/2024 1:03 PM, Alan Grayson wrote:
                and yields *different *real values for most
                different pairs.

-- You received this message because you are subscribed to
            the Google Groups "Everything List" group.
            To unsubscribe from this group and stop receiving emails
            from it, send an email to [email protected].
            To view this discussion on the web visit
            
https://groups.google.com/d/msgid/everything-list/ae301a72-9969-4e60-a132-0c8fe6d6f16cn%40googlegroups.com
            
<https://groups.google.com/d/msgid/everything-list/ae301a72-9969-4e60-a132-0c8fe6d6f16cn%40googlegroups.com?utm_medium=email&utm_source=footer>.

-- You received this message because you are subscribed to the
    Google Groups "Everything List" group.
    To unsubscribe from this group and stop receiving emails from it,
    send an email to [email protected].
    To view this discussion on the web visit
    
https://groups.google.com/d/msgid/everything-list/ddfc2b2c-28de-4338-b2eb-41d69bbcd58an%40googlegroups.com
    
<https://groups.google.com/d/msgid/everything-list/ddfc2b2c-28de-4338-b2eb-41d69bbcd58an%40googlegroups.com?utm_medium=email&utm_source=footer>.

--
You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/17a5202a-0dfd-4cfc-98fd-7e1e20e90f94n%40googlegroups.com <https://groups.google.com/d/msgid/everything-list/17a5202a-0dfd-4cfc-98fd-7e1e20e90f94n%40googlegroups.com?utm_medium=email&utm_source=footer>.

--
You received this message because you are subscribed to the Google Groups 
"Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To view this discussion on the web visit 
https://groups.google.com/d/msgid/everything-list/292cb676-7777-4d0d-9a9e-98900fa895f9%40gmail.com.

Reply via email to