Re: How does one calculate the metric tensor?

2024-10-03 Thread Alan Grayson
er tensors in Einstein's Field Equation because I am doubtful that it matters, since any tangent space on which the metric tensor is defined, will always contain an infinite set of vectors in the vector space defining that tangent space, so the same problem arises; namely, which pair of v

Re: How does one calculate the metric tensor?

2024-10-03 Thread Alan Grayson
er tensors in Einstein's Field Equation because I am doubtful that it matters, since any tangent space on which the metric tensor is defined, will always contain an infinite set of vectors in the vector space defining that tangent space, so the same problem arises; namely, which pair of v

Re: How does one calculate the metric tensor?

2024-10-02 Thread Alan Grayson
that it matters, since any tangent space on which the metric tensor is defined, will always contain an infinite set of vectors in the vector space defining that tangent space, so the same problem arises; namely, which pair of vectors must one chose, to calculate the metric tensor? TY, AG -- Yo

How does one calculate the metric tensor?

2024-10-02 Thread Alan Grayson
Wiki states it's a linear function of two variables whose domain is the vector space of velocity vectors on the tangent plane at some point P, say, on a spacetime manifold. But assuming we know the function, given by its 4x4 matrix representation defined on some coordinate system, which pair of

Re: Questions about the Metric Tensor and thenangent Space

2024-08-26 Thread Alan Grayson
2:13 AM (1 minute ago) >  >  >  > to Everything List > I've posed this question to several physicists, but so far none has been > able to solve it. Namely, since the metric tensor is defined on *vector > spaces on tangent planes on the spacetime* *manifold*, and it'

Re: Questions about the Metric Tensor and thenangent Space

2024-08-19 Thread Alan Grayson
[image: Alan Grayson's profile photo] Alan Grayson 2:13 AM (1 minute ago)    to Everything List I've posed this question to several physicists, but so far none has been able to solve it. Namely, since the metric tensor is defined on *vector spaces on tangent planes on the

Re: Questions about the Metric Tensor and the Tangent Space

2024-08-19 Thread Alan Grayson
I've posed this question to several physicists, but so far none has been able to solve it. Namely, if the metric tensor is defined on tangent spaces on the spacetime manifold, and it's a bilinear map to the real numbers, how do we know which pair of vectors to use to perform the c

Re: Questions about the Metric Tensor and thenangent Space

2024-08-17 Thread Alan Grayson
Wiki says the METRIC tensor is a bilinear function which maps to the real numbers. And the METRIC tensor FIELD is a scalar field, thus a real number at every point of spacetime. AG On Saturday, August 17, 2024 at 6:55:37 PM UTC-6 Brent Meeker wrote: You can't "resolve" a tenso

Re: Questions about the Metric Tensor and thenangent Space

2024-08-17 Thread Brent Meeker
You can't "resolve" a tensor into a number. Brent On 8/17/2024 3:59 PM, Alan Grayson wrote: Since the metric tensor is defined on the vector space on the tangent plane, it's defined on pairs (u, v), some of which can be tachyons. But how do we choose which pairs, with or

Re: Questions about the Metric Tensor and thenangent Space

2024-08-17 Thread Alan Grayson
Since the metric tensor is defined on the vector space on the tangent plane, it's defined on pairs (u, v), some of which can be tachyons. But how do we choose which pairs, with or without tachyons, to resolve the metric tensor into some real number? AG On Saturday, August 17, 2024 at

Re: Questions about the Metric Tensor and thenangent Space

2024-08-17 Thread Brent Meeker
the Metric Tensor, denoted as g (without its two subscripts), is a bilinear function of vectors *u *and*v,* in the *_vector_ _space_* resident in the tangent space, say at point P, of an underlying manifold, which maps to the real numbers. There’s also the concept of the Metric Tensor *Field*

Questions about the Metric Tensor and the Tangent Plane

2024-08-17 Thread Alan Grayson
According to Wikipedia and other reliable sources, the Metric Tensor, denoted as g (without its two subscripts), is a bilinear function of vectors *u *and* v,* in the *vector space* resident in the tangent space, say at point P, of an underlying manifold, which maps to the real numbers

Questions about the Metric Tensor and thenangent Space

2024-08-17 Thread Alan Grayson
According to Wikipedia and other reliable sources, the Metric Tensor, denoted as g (without its two subscripts), is a bilinear function of vectors *u *and* v,* in the *vector space* resident in the tangent space, say at point P, of an underlying manifold, which maps to the real numbers

Re: The Metric Tensor

2022-05-18 Thread Alan Grayson
On Tuesday, May 17, 2022 at 11:42:37 AM UTC-6 meeke...@gmail.com wrote: > Of course it depends on the energy distribution. That's what's on the > right side of Einstein's equation and if it's given you can solve for the > metric on the left side. The proper time between two time-like events

Re: The Metric Tensor

2022-05-17 Thread Brent Meeker
Of course it depends on the energy distribution.  That's what's on the right side of Einstein's equation and if it's given you can solve for the metric on the left side.  The proper time between two time-like events is the metric measure along a geodesic between them, which is  force-free path.

Re: The Metric Tensor

2022-05-15 Thread Alan Grayson
I'm getting it. Defined abstractly, without reference to any particular spacetime, the inner products from which the metric tensor derives, must be abstract. It's only by applying the EFE's that we can SOLVE for the specific metric tensor associated with a particular spacetime.

Re: The Metric Tensor

2022-05-15 Thread Alan Grayson
Looks like I'm spinning my wheels and getting nowhere, since the Metric Tensor has nothing to do any particular spacetime one is assuming and its energy distribution, when writing and trying to solve EFE's, since the inner products on the basis vectors in V, are completely arbitr

The Metric Tensor

2022-05-14 Thread Alan Grayson
It appears in Einstein's Field Equations and presumably allows us to calculate the Metric of spacetime, which is a bilinear map from a pair of spacetime coordinates to a real number. If the foregoing is correct, what is the definition of distance between any pair of spacetime points, and does i