Re: Analyse This!


Unfortunately or a fortunately, for the time being, a spacetime is usually a
manner to try to see as to try to figure out, anything which it should be a
flat but however, a pliant matter, on which would be a resting an heavy
round object, as, for instance, an iron ball.

Therefore, a weight of an iron ball would eventually cause a material on
which it would be sitting to stretch slightly.

However, it would be this, which it should be a roughly analogous along an
effect, that any mass of an any object, for instance the Sun itself has on a
spacetime along which it would strech and absolutely curve, and this is what
is all about.

--
Ahmed Ouahi, Architect
Best Regards!


"me" <ililililil@xxxxxxxxxxxx> wrote in message
news:1155850286.580415.31770@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Igor wrote:
me wrote:
Igor wrote:
me wrote:
Tom Roberts wrote:
Ahmed Ouahi, Architect wrote:
More or less reflexively, he dropped into his equations
something called the
cosmological constant, which arbitrarily counterbalanced the
effects of
gravity, serving as a kind of mathematical pause button.

Books on the history of science always forgive Einstein this
lapse, but it
was actually a fairly appalling piece of science and he knew
it. He called
it ' the biggest blunder of my life '. "

From today's perspective this was not a blunder at all.
Thinking
abstractly, one cannot eliminate from the Lagrangian any terms
that
satisfy the symmetries required of the theory (chiefly general
covariance). If one restricts the terms to those with no
derivatives
higher than the second, and requires linearity in those second
derivatives, one obtains the Lagrangian that yields the Einstein
field
equation, with cosmological constant. It is the simplest
non-trivial
Lagrangian that obeys the necessary symmetries.

It is, of course, up to experiments to determine the value of
the
cosmological constant. Until rather recently, the value was
"quite
small, consistent with zero"; with improved techniques we now
measure it
to be nonzero. Einstein originally favored zero, because then
the
Newtonian limit comes out correct; with a very small value,
however,
deviations from Newtonian mechanics would not be detectable.


Tom Roberts

if it is consistent with zero, who is expanding the universe


thank you for this email

You don't need a cosmological constant to provide expansion. In
fact,
Einstein originally used it to pull the universe back together, but

whay, was the gravity not strong enuff?

Not strong enough to maintain a static universe that wasn't expanding.

when the universe was found to actually be expanding,.he discarded
it.
Or haven't you been paying attention?

is it pushed from inside or is it pulled from outside?

It's the result of the big bang.

from inside or from outside?

No inside or outside on a manifold. There's just spacetime. The
actual "shape" of that manifold is what has always been debated.


this because there should be more vacum and empty space
outside than it is here inside

Where's this outside that you're talking about? GR models the
universe
as an open or closed spacetime manifold. There is no outside.

i tell you what, is somthing bigbang is exploding then
expanding, it does it against the outside

an imploding and contraction does it against inside

dont you know it? where have you been?

You don't know what you're talking about. Tell me where the inside and
outside are on the surface of a sphere. They don't exist. All you
have is the surface. Think of it in those terms. A spacetime manifold
is somewhat analagous to this, except in 4 dimensions instead of the 2
dimensions on the sphere.

thank you for this new e-mail

apparently you make things clear for me,
but still,

this surface to universe analogy went too
far, everybody use it, even reporters and
moviemakers, and obviously thay dont
know what they are talkin aboit

whay using a 2d surface analoguous to
a 4d manifold

whay not using 3d analogous to 4d



another question I have is about the big bang

if by using powerful telescopes
1. we can detect the primitive bigbang light and radiation
2. we can detect that everywhere in 3D
3. the distance to the bigbang light is increasing because
expansion

are we inside the bigbang now?

In a sense. We see the effects of the big bang all around us, but
the
temperature of the universe has cooled to just under 3 K.

thanks, now that you agree with inside, then an outside must
exists

Depends on whether you are talking about 3 dimensions of 4. In 3
dimensions, we appear to be inside something, but that space is not the
total picture and is emnbedded in 4 dimensional spacetime, where the

is it a rank 3 tensor with 4 elements?

universe is a self-contained manifold. No inside or outside. Now, you
might be able to come up with a theory where spacetime were embedded in
higher dimensions, but it would not be GR.

only a holywood filmmaker would do that



because if we reverese the expantion, then we have no choice, but
being inside the bigbang

That's called the big crunch, essentially running the big bang in
reverse. It was once thought that it might be the ultimate fate of
the
universe if there was sufficient total mass for gravity to overcome
the
outward expansion and pull everything back together again. But it
doesn't look like it will happen due to the accelerated expansion
that
we now see.

what is better, to expand or to impand?

Impand is not even a word. Why am I wasting my time?

no, you dont, you make things more clear to me, thanks



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