The Ping-Pong Ball and The Sun / S D Rodrian

On Oct 10, 1:23*pm, Aardvark wrote:
On Oct 10, 2:35 am, "Peter Webb"
Incorrect. Whilst the amount of "Sun mass"
pulling on him decreases, so does
his distance from the centre of the Sun
which causes the force of gravity to
increase (by a factor proportional to 1/r^2).

Do you even read what you're typing?
What you have just said is that "while he
is getting closer to the center of the Sun
his distance from the center of the Sun
decreases!" Your thinking processes may be
impaired, perhaps by alcohol (speculation).

He did not, liar.

I don't believe it is worth wasting time trying
to make you "see" that as he travels closer to
the center of he Sun the amount of mass "pulling
on him" is always decreasing--And how a

but at whot rate?

decreasing amount of mass can increase the
pull of gravity is something like expecting a
pebble resting on the surface of the earth to
suddenly fly off into space on its own!

He didn't say thet, liar.

Sir, think before you speak. And certainly THINK
before you type. And then please re-read it and
re-read it again. You'll come across much better.

you

"Aardvark" wrote in message
...
On Oct 10, 2:35 am, "Peter Webb"
wrote:
The instant Superman plunges past the
surface of the Sun, he will feel the pull
of the Sun's gravity begin to decrease.
And it will continue to decrease as he
flies towards the Sun's center.

[This is because as Superman travels
closer and closer to the center of the
Sun: the amount of Sun mass pulling
on him is decreasing, all the time that
there will be a growing amount of Sun-
mass behind him pulling back on his
super body. We can set aside the Sun
mass to the sides, but we must still
subtract it from the "pulling" mass.]

Incorrect. Whilst the amount of "Sun mass"
pulling on him decreases, so does
his distance from the centre of the Sun
which causes the force of gravity to
increase (by a factor proportional to 1/r^2).

Do you even read what you're typing?
What you have just said is that "while he
is getting closer to the center of the Sun
his distance from the center of the Sun
decreases!" Your thinking processes may be
impaired, perhaps by alcohol (speculation).
I don't believe it is worth wasting time trying
to make you "see" that as he travels closer to
the center of he Sun the amount of mass "pulling
on him" is always decreasing--And how a
decreasing amount of mass can increase the
pull of gravity is something like expecting a
pebble resting on the surface of the earth to
suddenly fly off into space on its own!


The mass decreases, but the distance to the centre of the mass also
decreases.

Newton's formula for acceleration (gravitational force) is

a = Gm/r^2

Whilst the value of the total mass enclosed (m in this case) decreases as
you move closer to the centre, so obviously does r, which acts to increase
the gravitational force as r decreases.

In a homogenous (constant density) body, the change in mass varies as r^3
but the distance varies as 1/r^2, so gravity decreases as you move towards
the centre. However, the earth, Sun, regular stars etc do not have constant
density, and in these cases it is very likely that the maximum acceleration
due to gravity lies well under the surface of these objects.

If you still don't believe it, I can give you a numeric counter-example.

Consider an astronomical object of radius 10r. It consists of a core of mass
m of radius r, and another far lighter shell going from x=r to x=10r also
of total mass m.

The gravitational acceleration on the surface of this body is:

A = force from central core + force from shell
= Gm/(10r)^2 + Gm/(10r)^2
= (2/100) * G m/r^2

The gravitational force at r=1 is:

A = force from central core + force from shell
= Gm/(r)^2 + 0

As you can see, the gravitational force at r=1 is 50 times greater than at
r=10 ie at the surface

Do you understand now? Is there any part of the above you don't understand?

Dear Alan Morgan:

"Alan Morgan" wrote in message
...
In article
,
Aardvark wrote:
....
Where does the pressure come from if there is no
gravity, you ask? There's no gravitational force at
the exact center, but most of the mass is
somewhere else and it is all feeling a force towards
the center. That's where the pressure comes from.

I think he should stand right between two incoming,
oppositely-directed 18-wheelers. According to his "logic", this
should be the safest place to be.

David A. Smith

On Oct 10, 8:38 pm, "Peter Webb" wrote:
"Aardvark" wrote in message
On Oct 10, 2:35 am, "Peter Webb"
wrote:
The instant Superman plunges past the
surface of the Sun, he will feel the pull
of the Sun's gravity begin to decrease.
And it will continue to decrease as he
flies towards the Sun's center.

[This is because as Superman travels
closer and closer to the center of the
Sun: the amount of Sun mass pulling
on him is decreasing, all the time that
there will be a growing amount of Sun-
mass behind him pulling back on his
super body. We can set aside the Sun
mass to the sides, but we must still
subtract it from the "pulling" mass.]

Incorrect. Whilst the amount of "Sun mass"
pulling on him decreases, so does
his distance from the centre of the Sun
which causes the force of gravity to
increase (by a factor proportional to 1/r^2).

Do you even read what you're typing?
What you have just said is that "while he
is getting closer to the center of the Sun
his distance from the center of the Sun
decreases!" Your thinking processes may be
impaired, perhaps by alcohol (speculation).
I don't believe it is worth wasting time trying
to make you "see" that as he travels closer to
the center of he Sun the amount of mass "pulling
on him" is always decreasing--And how a
decreasing amount of mass can increase the
pull of gravity is something like expecting a
pebble resting on the surface of the earth to
suddenly fly off into space on its own!

The mass decreases, but the distance to the centre
of the mass also decreases...

Please STOP RIGHT THE don't repeat the
nonsense you wrote (which I paraphrased
perhaps with too much sarcasm), Follow the
consequences of gravity acting on Superman
as he approaches the center of the Sun (NOT
in reality BUT as the laws of gravity would
have it be):

The Sun is not solid but a plasma ball. This
means it can expand (or contract) as much as
it needs to in order to accommodate behaving
as the laws of gravity say it ought to behave:

This means that every particle in it is free to
move to its region of the greatest gravitational
field strength from its region of lowest
gravitational field strength (even in its core,
which may be 10 times denser than lead, but
is still a plasma).

Are you suggesting that every one such particle
will move to the area of the least gravitational
field strength from the area of the highest
gravitational field strength? That's the whole
point of this series of posts right there.

There is no question that the Sun works exactly
as we all believe it does and that the highest
pressure exists at its core (I just told you how
much pressure there is there producing a
density 10 times greater than that of lead).

The question to consider is NOT how the SUN
actually behaves, but how would a plasma ball
like the Sun behave were it indeed obeying the
classically delineated laws of gravity (that say the
strength of gravity acting on a body descending
to its center decreases. Do you understand now?

I guess it's true: no one understands sarcasm.

A solid ball may convey pressures from one point
to others, but a plasma ball like the Sun would
(were it only under the design of gravity alone)
eventually describe in space the field(s) of gravity
acting upon it ... exactly like iron filings describe
the fields of a magnet acting on them.

And then you would have to "see" its mass (the
equivalent of the Sun's iron filings) describing
a "more massive" shell around a "less massive"
center.

We don't see that (in fact, it is a physical
impossibility because then the Sun would not
be ON).

Don't miss the forest for the trees.

S D Rodrian
http://sdrodrian
http://physics.sdrodrian.com
http://mp3.sdrodrian.com


..

"Aardvark" wrote in message
...
On Oct 10, 8:38 pm, "Peter Webb" wrote:
"Aardvark" wrote in message
On Oct 10, 2:35 am, "Peter Webb"
wrote:
The instant Superman plunges past the
surface of the Sun, he will feel the pull
of the Sun's gravity begin to decrease.
And it will continue to decrease as he
flies towards the Sun's center.

[This is because as Superman travels
closer and closer to the center of the
Sun: the amount of Sun mass pulling
on him is decreasing, all the time that
there will be a growing amount of Sun-
mass behind him pulling back on his
super body. We can set aside the Sun
mass to the sides, but we must still
subtract it from the "pulling" mass.]

Incorrect. Whilst the amount of "Sun mass"
pulling on him decreases, so does
his distance from the centre of the Sun
which causes the force of gravity to
increase (by a factor proportional to 1/r^2).

Do you even read what you're typing?
What you have just said is that "while he
is getting closer to the center of the Sun
his distance from the center of the Sun
decreases!" Your thinking processes may be
impaired, perhaps by alcohol (speculation).
I don't believe it is worth wasting time trying
to make you "see" that as he travels closer to
the center of he Sun the amount of mass "pulling
on him" is always decreasing--And how a
decreasing amount of mass can increase the
pull of gravity is something like expecting a
pebble resting on the surface of the earth to
suddenly fly off into space on its own!

The mass decreases, but the distance to the centre
of the mass also decreases...

Please STOP RIGHT THE don't repeat the
nonsense you wrote (which I paraphrased
perhaps with too much sarcasm),

Consider an astronomical object of radius 10r. It consists of a core of mass
m of radius r, and another far lighter shell going from x=r to x=10r also
of total mass m.

The gravitational acceleration on the surface of this body is:

A = force from central core + force from shell
= Gm/(10r)^2 + Gm/(10r)^2
= (2/100) * G m/r^2

The gravitational force at r=1 is:

A = force from central core + force from shell
= Gm/(r)^2 + 0

As you can see, the gravitational force at r=1 is 50 times greater than at
r=10 ie at the surface

Do you understand now? Is there any part of the above you don't understand?

On Oct 8, 11:37 pm, "Nightcrawler"
wrote:
"John Santos" .
edu wrote in messagenews:
MPG.2538809c369d2948989686
@news.giganews.com...
No. This is where you go wrong.
It would *not* stop.
All the while it was approaching the center
of the Sun, it would
continue to accelerate, though the rate
of acceleration would
decline to 0 at the center. However,
it would continue to
possess all the velocity, momentum and
kinetic energy it had
acquired while accelerating downward.
As it reached the center,
it would have exactly enough velocity to
reach the surface of
the Sun on the other side, plus whatever
initial velocity it
had when it first reached the surface
of the Sun. So it would
go flying off into space after emerging
from the far side of
the Sun. (If it had originally fallen
from a long distance,
such as interstellar space, it would
eventually fly off again
and never return, since the velocity
it would acquire falling
from interstellar space to the surface
of the Sun would be
exactly the escape velocity *from*
the surface of the sun.
It is easy to prove this by conservation
of energy, as well
as by a detailed integration
of the forces involved.
All your subsequent conclusions are
incorrect, due to this
fundamental error.

That misunderstanding is why I substituted
Superman for the ping-pong ball AND YET
so many monkeys [yes: here] continued to
misunderstand my simple little thought-
experiment that I despair of my fellow
monkeys ever evolving into thinking beings
any time in the near future. --SDR

Of course, the OP did not state that
the ping pong ball would
be immune to the density of the matter
within the sun. So, the
ball would essentially just get buffeted
around and most likely
would never even get close to the sun.

This poster is obviously slowing crawling
his way towards becoming some sort of
hominid. He is probably capable of standing
upright and his legs are also probably
longer than his arms now (from his post).

He's also in error in that he is
presuming that the matter of the
sun will not press in and fill any voids

Unfortunately he's thinking of the Sun
sphere more like a vessel in his hand
here on earth [instead of a free-floating
ball of gas/plasma out in space] wherein
the more water he pours into his vessel
the more it weighs (whereas the whole
entire Sun doesn't really weigh anything
whatever at all [pouring "more" into it
doesn't really make it "weigh" more]:
the Sun's "weights" are all relativistically
spread about/inside its space... much like
"a pound of stuff" only weighs a pound
on the surface of the earth... and if it
is out "in space" it weighs nothing whatever
at all--you know, much like the Sun itself).

This monkey, unlike the other poster, may
be able to stand upright, but he's still a
poor ole monkey, pure & simple...

that there are, and specifically
ignores the fact that the sun is a fusion
reactor which needs a
constant supply of fuel to maintain
the reaction. If there was a

"if there were" ...

"void", then the reaction would stop.

Yes! --That-- happens to be my point:

The ongoing fusion reaction proves that
in the Sun sphere Gravity could NOT be
working as it OUGHT TO BE working:

There is NO MECHANISM in a gas/plasma
ball (large enough for 1,300,000 Earths
to fit in it) for the outer shell mass to
transmit enough cumulative pressures
to the core ... since gravity is actually
declining the closer one gets to the co

There are too many earth-masses around
every earth-mass at, say, 1/4 of the way
to the core pulling out towards the surface
for it to "press" all its mass towards the
co In the end, once you start getting to
98/100th of the way to the core those earth-
masses are pressing more against core-
wards than core-wise [or, negative gravity
--at the core itself there should be no
gravity pressure at all]. Not being ONE
SOLID BALL the earth-masses in the Sun
have no way to add their gravitational
pressure towards the core. SINCE they
are obviously not falling towards the center
like Newton apples but existing in place. Or:

Imagine not an earth-mass but one given
atom "existing" inside the Sun sphe
ANYWHERE YOU PLACE IT it will always
"feel" less and less "pull" towards the center
the closer to the center you put it. THE SUM
RESULT being:

The Sun is undergoing the pressure it's
undergoing at its core NOT because of
"gravitational pressures" but due to some
other mechanism--And that mechanism...
a velocity pressing towards center(s) ever
since the beginning of time, is explained
he

http://physics.sdrodrian.com

S D Rodrian
http://sdrodrian.com
http://mp3.sdrodrian.com
http://islamisbad.com


"Give it up. Dude:
We are monkeys."

Oh, yeah. Sorry.

"Eat our feces, dude."



..

There is NO MECHANISM in a gas/plasma
ball (large enough for 1,300,000 Earths
to fit in it) for the outer shell mass to
transmit enough cumulative pressures
to the core ... since gravity is actually
declining the closer one gets to the co


Gravity doesn't actually necessarily decrease as you get closer to the
centre. This has been pointed out to you several times. It is zero at the
centre, as you say.

Pressure however is at its maximum in the centre. It is caused by the
"weight" of the Sun's mass bearing down on its centre. While bits of the Sun
at the very centre have no "weight", all the rest of the Sun does.

You will note that gravity and pressure and very different things. Gravity
is most usually defined as a "force" with units of mass x length x
time^(-2), pressure is a force per unit area with units of mass x
length^(-1) x time^(-2).

Later when you learn the "ideal gas law" and some basic calculus, you will
be able to model the pressure inside the Sun at various depths by assuming
it is comprised of an ideal gas and it is in thermal equilibrium. This will
give you a better feel for what is going on.

HTH

On Oct 26, 12:08*am, "Peter Webb"
wrote:
There is NO MECHANISM in a gas/plasma
ball (large enough for 1,300,000 Earths
to fit in it) for the outer shell mass to
transmit enough cumulative pressures
to the core ... since gravity is actually
declining the closer one gets to the co

Gravity doesn't actually necessarily decrease as you get closer to the
centre. This has been pointed out to you several times. It is zero at the
centre, as you say.

Pressure however is at its maximum in the centre. It is caused by the
"weight" of the Sun's mass bearing down on its centre. While bits of the Sun
at the very centre have no "weight", all the rest of the Sun does.

You will note that gravity and pressure and very different things. Gravity
is most usually defined as a "force" *with units of mass x length x
time^(-2), pressure is a force per unit area with units of mass x
length^(-1) x time^(-2).

Later when you learn the "ideal gas law" and some basic calculus, you will
be able to model the pressure inside the Sun at various depths by assuming
it is comprised of an ideal gas and it is in thermal equilibrium. This will
give you a better feel for what is going on.

HTH

Monkeys, sir: Monkeys!

S D Rodrian
http://sdrodrian
http://physics.sdrodrian.com
http://mp3.sdrodrian.com

..

On Oct 26, 1:51 am, BradGuth
wrote:
Gravity Force Inside a Spherical Shell
(is always zero)

http://hyperphysics.phy-astr.gsu.edu...ell2.html#wtls

So, how thick is the shell or
gaseous outer wall of our sun?

If the universe operated as described
by classical laws of gravity (e.g. via
your mythical graviton) then probably
the Sun would look like a big frozen
planet (along with every other star).
The "shell" might simply descend in
density to a least dense center, that's all.

Fortunately the universe doesn't look
inside the craniums of men to learn
how it's permitted to work (or not):

Eventually men LEARN the Earth isn't flat.
That the universe does not revolve around
their itty bitty planet. And that the reason
why gravitational anomalies suffuse the
universe everywhere they look is NOT
because "God likes lo create complex
puzzles with wandering planets, and
gravitational forces that don't act on the
parts of a mass just on the whole of it"
BUT because they have yet to fully grasp
(understand) exactly how perfectly simple
the workings of the universe really are.

You can learn a bit of it by traveling to:

http://physics.sdrodrian.com

You will have to shut your mind to the bunk
more primitive monkeys than you have come
up with throughout theis ascent from more
primitive ages... to our howling day. But it
can be done (by most monkeys, if not all).

Good luck!

S D Rodrian
http://sdrodrian.com
http://physics.sdrodrian.com
http://mp3.sdrodrian.com




..

On Oct 29, 7:59 pm, "Peter Webb" wrote:
"Aardvark" wrote in message

If the universe operated as described
by classical laws of gravity (e.g. via
your mythical graviton) then probably
the Sun would look like a big frozen
planet (along with every other star).
The "shell" might simply descend in
density to a least dense center, that's all.

The Sun is a fluid.

On earth, more dense objects sink in fluids,
and less dense objects float.
But you believe that on the Sun, the highest
density matter floats on top of
less dense matter?

You're not thinking straight:

I do not claim that the universe works
in any way differently from how we
know it works.

I do know that if gravity were producing
"the effects of gravity," then the universe
could NOT work the way we know it works
(from the way gravity should work if it were
to work according to its own laws).

ERGO my scenario of a "less dense core"
for the Sun... if the universe worked according
to the laws of gavity.

The Sun does not actually have a less
dense core BECAUSE (see Newton's laws
of motion) since the beginning of the
universe everything in it has been
accelerating towards ITS CENTER(s).

NOTE: Not towards "a" center because
the sum total of its matter IS its center.
THERE is no other matter in the universe
than matter---I know this simplicity
is hard for monkeys to grasp. And I have
great sympathy for you, believe me.
But eventually you will all understand it;
just as you now understand that the math
that proved Ptolemy's earh-centered notion
didn't really prove anything except perhaps
the over-cleverness of us monkeys.

In affect, the universe is acting like
THE MOTHER OF ALL BLACK HOLES
with every "bit of matter in it" being
its "point of infinite density" (the very
obviously misnamed "singularity").

EVERYTHING about us is telling us
this is the case, but we are not yet
prepared (as a monkey society) to see it
(only I can see it--others may see it as
well, or perhaps blurrily, sooner or later).

THAT is why denser (the more mass, given
the same space) stuff "moves" toward center
with "greater weight" (more impetus) than
less massive matter (and why nearly mass-
less particles like the photon seen to shoot
about AT AN ALMOST INCREDIBLY CONSTANT
SPEED regardless of where in the universe
they are). And without knowing each other.

And why, the photon, after it slows down
while passing through a denser medium
suddenly re-speeds up after it hits a less
dense medium, and WITHOUT having to fire
any after-burners!

It's all explained from several different angles
at:

http://physics.sdrodrian.com

and in a plain/simple English language
which even a six year old can follow.

See if you can,

S D Rodrian
http://sdrodrian.com
http://physics.sdrodrian.com
http://mp3.sdrodrian.com

..