A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Others » Misc
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Descent Thoughts (was - something and nothing)



 
 
Thread Tools Display Modes
  #11  
Old June 24th 03, 01:12 PM
G=EMC^2 Glazier
external usenet poster
 
Posts: n/a
Default Descent Thoughts (was - something and nothing)

Hi Panius What you described is why quantum gravity is better than GR
Its a particle attraction Try using curved space in your scenario.
Thing is you would get lighter,and lighter as you went deeper and
deeper,and you would know you were at the center of the earth when your
weight was zero. Quantum gravity,and general relativity are not
compatible. I have my own theory of gravity,and it comes out of QM
Bert

  #12  
Old June 25th 03, 01:35 PM
Painius
external usenet poster
 
Posts: n/a
Default Descent Thoughts (was - something and nothing)

"Odysseus" wrote...
in message ...

G=EMC^2 Glazier wrote:

Hi Odysseus Just don't want you and Sally stuck between floors in an
elevator. I say it will finally come to rest at the center of the
earth,and you say it will stop and go,and stop and go forever. Seems the
elevator would have a greater force of gravity on its sides than top to
bottom? That is another reason for it slowing down,and slowing down is
what we are really discussing. I say it will . Bert


You're the only one talking about "stopping and starting".

As for "a greater force of gravity on its sides" I can't imagine what
you mean. The radial components (WRT the 'axis' of the tunnel) of the
gravitational forces will cancel each other out; only their axial
components need be considered.

But if we let reality intrude into this discussion far enough to
admit the effects of friction the elevator will certainly make
smaller and smaller 'orbits' and eventually stop, in a pattern one
might call a 'damped oscillation'; neither Sally nor I have claimed otherwise.

--Odysseus


Alas! forgotten about again... must be my face... i just have one of
those "forgettable" faces.

"A greater force of gravity on its sides" indeed does mean what you
are calling the radial components. They stretch from the axis of the
tunnel out in all 3 dimensional directions toward the Earth's surface.
Disregarding the reality check of other frictional effects and just
focusing upon these radial components of gravitational force, i do
not believe that they will cancel out entirely.

If Earth were a sphere whose surface were smooth and whose
innards were uniformly and consistently dense, then yes, the radial
components would cancel out. Since this is not the case, since the
Earth's surface is not perfectly smooth and since its inner volume
varies in density, then these radial components would not cancel
out and would have an effect on anything that oscillates within the
tunnel. The effect would then be a sort of gravitational "friction"
that would dampen the oscillations. And this (i realize that i'm
being loose with my terminology here) gravitational friction would
also affect every cubic cm of material within Earth's surface,
wouldn't it?

Now let's imagine spreading out from Earth's surface and including
the atmosphere as well. Of course, such a mental exercise might
be easier to do on a planet such as Jupiter or Saturn, since their
"atmospheres" make up the vast majority of their huge volumes.

happy days and...
starry starry nights!

--
Planets, stars and nebulae
Hold attention in the sky--
Lay in hay and squint your eye,
Lose your youth in moaning sigh
& find the truth in every lie!

Paine Ellsworth


  #13  
Old June 25th 03, 01:52 PM
Painius
external usenet poster
 
Posts: n/a
Default Descent Thoughts (was - something and nothing)

"G=EMC^2 Glazier" wrote in message...
...

Hi Panius What you described is why quantum gravity is better than GR
Its a particle attraction Try using curved space in your scenario.
Thing is you would get lighter,and lighter as you went deeper and
deeper,and you would know you were at the center of the earth when your
weight was zero. Quantum gravity,and general relativity are not
compatible. I have my own theory of gravity,and it comes out of QM
Bert


I agree.

I also think that GR is weak in that it describes an effect rather
than a cause. But QG is also weak in that it is so ill-understood.

QG is the cause that results in the effects described by GR, but
we still don't have much of a handle on either.

It is difficult to reconcile observations with reality, probably due,
at least in part, to the fact that the very act of observing distorts
reality.

We try to be a fly on the wall, but we get swatted every time!

happy days and...
starry starry nights!

--
I'm a fool upon a hill,
See my planet spinning still?
Sun goes down and stars arise
Warm and pleasing to my eyes.

See my little telescope?
People say I'm such a dope;
I don't mind because I nurse
Secrets of the Universe!

Paine Ellsworth


  #14  
Old June 25th 03, 03:01 PM
G=EMC^2 Glazier
external usenet poster
 
Posts: n/a
Default Descent Thoughts (was - something and nothing)

Hi Odysseus It is a "given" that the object comes to a complete stop
at each end of the earth(it is going back and forth (yes) There is no
air in the tunnel,so I only used "gravity friction" Just a term,and if
you would like I'll disregard it. I did not let Sally take away the
earth's rotation,for I liked leaving that in to strengthen my side of
this discussion. I would like Scott Miller to add his thoughts,for we
don't always agree,and that is good. Bert

  #15  
Old June 26th 03, 04:01 AM
Odysseus
external usenet poster
 
Posts: n/a
Default Descent Thoughts (was - something and nothing)

Painius wrote:

"A greater force of gravity on its sides" indeed does mean what you
are calling the radial components. They stretch from the axis of the
tunnel out in all 3 dimensional directions toward the Earth's surface.
Disregarding the reality check of other frictional effects and just
focusing upon these radial components of gravitational force, i do
not believe that they will cancel out entirely.

If Earth were a sphere whose surface were smooth and whose
innards were uniformly and consistently dense, then yes, the radial
components would cancel out. Since this is not the case, since the
Earth's surface is not perfectly smooth and since its inner volume
varies in density, then these radial components would not cancel
out and would have an effect on anything that oscillates within the
tunnel. The effect would then be a sort of gravitational "friction"
that would dampen the oscillations. And this (i realize that i'm
being loose with my terminology here) gravitational friction would
also affect every cubic cm of material within Earth's surface,
wouldn't it?

I agree with you up to where you say the imbalanced radial forces
would cause damping. I think they'd just perturb the 'orbit' a
little. If the walls of the tunnel are frictionless and perfectly
elastic, even if the car goes 'off course' far enough to collide with
them no energy will be lost. Of course if those conditions aren't met
there will be a damping effect.

Putting it another way, for conservation of mechanical energy to be
violated there must be "dissipative" forces at work, and AFAIK
gravity is not one of them.

--Odysseus
  #16  
Old June 26th 03, 08:53 PM
Sally
external usenet poster
 
Posts: n/a
Default Descent Thoughts (was - something and nothing)

If you introduce factors into our thought experiment that are known to
produce friction and dissipate energy then, lo and behold, there will be
friction and the oscillations will get smaller.

Sally
"G=EMC^2 Glazier" wrote in message
...
Hi Odysseus Reaching the earth's center might not be its center of
gravity? The tunnel might be curved this way and that.The reason is all
the earth's particles would have to be perfectly homogenized for the
tunnel,and the object in it to go north and south in a straight line.
The earth does wobble. The 8 thousand mile distance would make this
effect noticeable. Like I've stated a tunnel going through
the earth in not an isolate system. Lots of stuff to take energy
away,even with out air friction. Bert



  #17  
Old June 26th 03, 10:24 PM
G=EMC^2 Glazier
external usenet poster
 
Posts: n/a
Default Descent Thoughts (was - something and nothing)

Hi Sally Seems energies can't be destroyed but they can be
transferred.and most end up as heat created by friction. Throw a rock in
the pond,and its energy creates an up and down wave that moves towards
the shore line,and it ends up rippling against the sandy shore and that
causes friction,and this up down wave action ends up as heat. Sally I
hope you did not think I was Cheating? The pond wave did not lose its
energy by air friction. The rock hitting the water proved that water is
non-compressible.. Bert

  #18  
Old June 27th 03, 12:09 PM
Sally
external usenet poster
 
Posts: n/a
Default Descent Thoughts (was - something and nothing)

You are quite right about the rock and its energy transfer into waves.
Similarly, if our falling/rising elevator undergoes massive acceleration due
to the G field then it may radiate gravity waves and therefore lose some
energy. This is analogous to accelerating charged particles transferring
some energy into/from electromagnetic radiation. However I said, right at
the start, that I was assuming a none-relativistic scenario. If you want to
modify the experiment so that the elevator is falling into a black hole then
I will agree that it may radiate some energy by various means, especially as
it nears the event horizon.

In the original Newtonian experiment we could construct a blockage in the
shaft and the elevator will then crash into it. Much of the energy will then
be converted to heat while some will be transferred into shock waves which
will radiate from the crash scene...just like the water waves. However, you
have now added extra features to the experiment and I will readily agree
that in this case the elevator will certainly slow down :-)

Look at masses in elliptical orbits. They are constantly moving through
gravity fields of changing intensity. Yet the only orbital decay is due to
frictional interactions with their environment, either directly or via tidal
forces.

Yes, I do know about Mercury and its orbital discrepancies which were seen
as confirmation of the theory of General Relativity. (Or was it Special
Relativity? I've forgotten...)

Sally

"G=EMC^2 Glazier" wrote in message
...
Hi Sally Seems energies can't be destroyed but they can be
transferred.and most end up as heat created by friction. Throw a rock in
the pond,and its energy creates an up and down wave that moves towards
the shore line,and it ends up rippling against the sandy shore and that
causes friction,and this up down wave action ends up as heat. Sally I
hope you did not think I was Cheating? The pond wave did not lose its
energy by air friction. The rock hitting the water proved that water is
non-compressible.. Bert



  #19  
Old June 28th 03, 01:56 PM
G=EMC^2 Glazier
external usenet poster
 
Posts: n/a
Default Descent Thoughts (was - something and nothing)

Hi Sally You mentioned "massive acceleration" Gravity is not a
constant. You enter the elevator,and it has a rate of fall indicator.
What would be your rate of fall at the 2,000 mile depth? That is half
way to the earth's center.(gravity is a particle attraction) Would your
rate of fall always be a positive 32 ft per second per second passing
though the earth's center? Now going up hill you decelerating and again
you have the same problem. Falling to the earth,or
falling towards a blackhole are different,for you don't have
particles(gravity) trying to pull in the opposite direction. Falling
through a tunnel going through the earth this is a continual problem.
Walking between two mountains their particle attraction is trying to
pull you towards them,but it is to weak to effect you. This is not the
case deep inside the earth (like 2,000 miles down) Sally this is
why a pendulum slows down even in a vacuum. Rotation is a lot better
than stop and go. We have a metal disc floating on top of a magnetic
field spinning in a vacuum,and its been spinning for 75 years.
Bert

  #20  
Old June 28th 03, 02:43 PM
G=EMC^2 Glazier
external usenet poster
 
Posts: n/a
Default Descent Thoughts (was - something and nothing)

What if the universe needs two separate laws? QM for the micro
universe,and GR for the macro universe. In the micro universe we use
Planck scales for measurements and to give you an idea these scales are
smaller than atoms by just as much as atoms are smaller than stars..
Now I've mentioned micro blackholes and macro blackholes,and I think
they will link the micro universe with the macro universe. There has to
be a link with the singularity in the core of every blackhole,and the
time before the big bang. Einstein's GR predicted blackholes,and QM is
needed to explain their singularity,and this will unite the two.
Blackholes are their common denominator. Its gravity all the way
down. Bert

 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT +1. The time now is 07:59 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.