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What if the Earth were Hollow?

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  What if the Earth were Hollow? Sam Wormley <swormley1@gmail.com> - 2015-10-30 20:32 -0500
    Re: What if the Earth were Hollow? gilber34 <fafa@invalid.com> - 2015-10-30 21:01 -0500
      Re: What if the Earth were Hollow? Fabian Russell <root@localhost.localdomain> - 2015-10-31 02:39 +0000
        Re: What if the Earth were Hollow? gilber34 <fafa@invalid.com> - 2015-10-30 22:11 -0500
          Re: What if the Earth were Hollow? Fabian Russell <root@localhost.localdomain> - 2015-10-31 03:21 +0000
            Re: What if the Earth were Hollow? "nuny@bid.nes" <Alien8752@gmail.com> - 2015-10-31 09:01 -0700
              Re: What if the Earth were Hollow? benj <none@gmail.com> - 2015-10-31 13:40 -0400
              Re: What if the Earth were Hollow? Fabian Russell <root@localhost.localdomain> - 2015-10-31 18:10 +0000
                Re: What if the Earth were Hollow? Mahipal <mahipal7638@gmail.com> - 2015-10-31 11:38 -0700
                  Re: What if the Earth were Hollow? Fabian Russell <root@localhost.localdomain> - 2015-10-31 19:40 +0000
            Re: What if the Earth were Hollow? xxein1@att.net - 2015-10-31 09:52 -0700
              Re: What if the Earth were Hollow? gilber34 <fafa@invalid.com> - 2015-10-31 12:39 -0500
              Re: What if the Earth were Hollow? "nuny@bid.nes" <Alien8752@gmail.com> - 2015-11-01 04:11 -0800
                Re: What if the Earth were Hollow? Fabian Russell <root@localhost.localdomain> - 2015-11-01 17:40 +0000
    Re: What if the Earth were Hollow? jimp@specsol.spam.sux.com - 2015-10-31 02:24 +0000
    Re: What if the Earth were Hollow? "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-10-31 12:16 -0700
    Re: What if the Earth were Hollow? Lofty Goat <rlwatkins@gmail.com> - 2015-10-31 18:17 -0500
      Re: What if the Earth were Hollow? Sam Wormley <swormley1@gmail.com> - 2015-10-31 19:32 -0500
    Re: What if the Earth were Hollow? "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-01 14:56 -0800

#529318 — What if the Earth were Hollow?

What if the Earth were Hollow?
> https://www.youtube.com/watch?v=jN-FfJKgis8

   What if there were a tunnel through the middle of the earth and the
   jimp jumped in?

-- 

sci.physics is an unmoderated newsgroup dedicated
to the discussion of physics, news from the physics
community, and physics-related social issues.

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#529330

On 10/30/2015 8:32 PM, Sam Wormley wrote:
> What if the Earth were Hollow?
>>
>
>    What if there were a tunnel through the middle of the earth and the
>    jimp jumped in?
>

he would get roasted as he passed through.

Questions:

is this tunnel lined ?   What material would stand the heat ?

Would jimp be radioactive after the first pass through ?

Is the tunnel full of Air ?

would the air pressure slow him down as he neared the center ?

How long would it take for him to reach the center including air pressure ?

Extra Credit -draw the curve of air pressure vs. depth below surface in 
the tunnel.

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#529357

On Fri, 30 Oct 2015 21:01:04 -0500, gilber34 wrote:

> 
> he would get roasted as he passed through.
> 

You wouldn't even pass through.  Because of the differential
rotational speeds, you'd smash against the wall very quickly.

Question: What shape does a tunnel have to be to allow a complete
passage?

 

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#529366

On 10/30/2015 9:39 PM, Fabian Russell wrote:
> On Fri, 30 Oct 2015 21:01:04 -0500, gilber34 wrote:
>
>>
>> he would get roasted as he passed through.
>>
>
> You wouldn't even pass through.  Because of the differential
> rotational speeds, you'd smash against the wall very quickly.

wouldnt quite be a smash, but definatly pushed into the wall, if the 
wall was slick he could slide down, but that friction constant would 
need to be included.
if a lot of friction, he could be stuck there,



>
> Question: What shape does a tunnel have to be to allow a complete
> passage?


with or without air in the tunnel ?

with, prob a strange sprial

without .......

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#529369

On Fri, 30 Oct 2015 22:11:20 -0500, gilber34 wrote:

>>
>> Question: What shape does a tunnel have to be to allow a complete
>> passage?
> 
> 
> with or without air in the tunnel ?
> 
> with, prob a strange sprial
> 
> without .......
>

Let consider without air.  Dropping a ball at the surface is
essentially putting an object into orbit with an initial velocity
equal to the rotational speed at the latitude of the drop.
The path then would have to be an ellipse.

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#529421

On Friday, October 30, 2015 at 8:21:53 PM UTC-7, Fabian Russell wrote:
> On Fri, 30 Oct 2015 22:11:20 -0500, gilber34 wrote:
> 
> >>
> >> Question: What shape does a tunnel have to be to allow a complete
> >> passage?
> > 
> > 
> > with or without air in the tunnel ?
> > 
> > with, prob a strange sprial
> > 
> > without .......
> >
> 
> Let consider without air.  Dropping a ball at the surface is
> essentially putting an object into orbit with an initial velocity
> equal to the rotational speed at the latitude of the drop.
> The path then would have to be an ellipse.

  Yes, if the Earth didn't rotate.


  Mark L. Fergerson

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#529438

On 10/31/2015 12:01 PM, nuny@bid.nes wrote:
> On Friday, October 30, 2015 at 8:21:53 PM UTC-7, Fabian Russell wrote:
>> On Fri, 30 Oct 2015 22:11:20 -0500, gilber34 wrote:
>>
>>>>
>>>> Question: What shape does a tunnel have to be to allow a complete
>>>> passage?
>>>
>>>
>>> with or without air in the tunnel ?
>>>
>>> with, prob a strange sprial
>>>
>>> without .......
>>>
>>
>> Let consider without air.  Dropping a ball at the surface is
>> essentially putting an object into orbit with an initial velocity
>> equal to the rotational speed at the latitude of the drop.
>> The path then would have to be an ellipse.
>
>    Yes, if the Earth didn't rotate.
>
>
>    Mark L. Fergerson

why drill a tunnel, Mark, when there is already a nice hole into the 
hollow center near the North pole?  Oh that's right, the physics is more 
interesting down at the equator!



-- 

       ___           ___           ___            ___
      /\  \         /\  \         /\__\          /\  \
     /::\  \       /::\  \       /::|  |         \:\  \
    /:/\:\  \     /:/\:\  \     /:|:|  |     ___ /::\__\
   /::\~\:\__\   /::\~\:\  \   /:/|:|  |__  /\  /:/\/__/
  /:/\:\ \:|__| /:/\:\ \:\__\ /:/ |:| /\__\ \:\/:/  /
  \:\~\:\/:/  / \:\~\:\ \/__/ \/__|:|/:/  /  \::/  /
   \:\ \::/  /   \:\ \:\__\       |:/:/  /    \/__/
    \:\/:/  /     \:\ \/__/       |::/  /
     \::/__/       \:\__\         /:/  /
      ~~            \/__/         \/__/

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#529446

On Sat, 31 Oct 2015 09:01:37 -0700, nuny@bid.nes wrote:

> 
>   Yes, if the Earth didn't rotate.
> 

Rotation is only an extra factor if one is concerned about the
precise location of the exit point.

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#529457

On Saturday, October 31, 2015 at 2:10:03 PM UTC-4, Fabian Russell wrote:
> On Sat, 31 Oct 2015 09:01:37 -0700, nuny@bid.nes wrote:
> > 
> >   Yes, if the Earth didn't rotate.
> > 
> Rotation is only an extra factor if one is concerned about the
> precise location of the exit point.

If if if... anybody ever seen a hollow Earth? Anybody? Got selfies?

In a hollow sphere, Earth or otherwise, no mass is moving anywhere.
The gravitational attraction/repulsion is zero at all points inside
the hollow sphere. You all must be too ...youKnow to remember having
to mathematically prove for homework this shell game problem.

https://www.google.com/?gws_rd=ssl#q=gravity+inside+hollow+sphere   
In the age of ALPHABET, I just redid all you's homework for you.
Now hide your faces in your #smartestphones and click Click CLICK...

-- Mahipal "IPMM, You're welcome... hold your applause... humble me."

Mark, you'll like/remember this song: Supertramp, Hide In Your Shell
https://www.google.com/?gws_rd=ssl#q=Supertramp:+Hide+In+Your+Shell

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#529482

On Sat, 31 Oct 2015 11:38:45 -0700, Mahipal wrote:

> 
> If if if... anybody ever seen a hollow Earth? Anybody? 
> 

It's all just a theoretical exercise.  The challenge is to develop
the mathematical equations to describe the motion.

The gravity train is one example.  Such a train could provide
powerless transport between surface points on the globe by digging
a tunnel of a certain shape.

 









> In a hollow sphere, Earth or otherwise, no mass is moving anywhere.
> The gravitational attraction/repulsion is zero at all points inside
> the hollow sphere. You all must be too ...youKnow to remember having
> to mathematically prove for homework this shell game problem.
> 
> https://www.google.com/?gws_rd=ssl#q=gravity+inside+hollow+sphere   
> In the age of ALPHABET, I just redid all you's homework for you.
> Now hide your faces in your #smartestphones and click Click CLICK...
> 
> -- Mahipal "IPMM, You're welcome... hold your applause... humble me."
> 
> Mark, you'll like/remember this song: Supertramp, Hide In Your Shell
> https://www.google.com/?gws_rd=ssl#q=Supertramp:+Hide+In+Your+Shell

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#529423

On Friday, October 30, 2015 at 11:21:53 PM UTC-4, Fabian Russell wrote:
> On Fri, 30 Oct 2015 22:11:20 -0500, gilber34 wrote:
> 
> >>
> >> Question: What shape does a tunnel have to be to allow a complete
> >> passage?
> > 
> > 
> > with or without air in the tunnel ?
> > 
> > with, prob a strange sprial
> > 
> > without .......
> >
> 
> Let consider without air.  Dropping a ball at the surface is
> essentially putting an object into orbit with an initial velocity
> equal to the rotational speed at the latitude of the drop.
> The path then would have to be an ellipse.

xxein:  I'm starting to have trouble here.  The video says that once inside, gravity is equal in every direction.  I can't buy that.  If the whole mass was homogeneous, then I could.  But not for the empty shell scenario.

That aside for the moment, if once inside, gravity is equal in all directions, - how could you expect a ball to drop?

Then it depends on where you drill the hole also.  Pole (no lateral rotation) or equator (max lateral rotation).  Hollow below surface, homogeneous or mantle and core.

IOW, I lost where we're at and disagree with the video.  ???  There's probably more.

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#529437

On 10/31/2015 11:52 AM, xxein1@att.net wrote:
> On Friday, October 30, 2015 at 11:21:53 PM UTC-4, Fabian Russell
> wrote:
>> On Fri, 30 Oct 2015 22:11:20 -0500, gilber34 wrote:
>>
>>>>
>>>> Question: What shape does a tunnel have to be to allow a
>>>> complete passage?
>>>
>>>
>>> with or without air in the tunnel ?

>>> with, prob a strange sprial
>>>
>>> without .......
>>>

>> Let consider without air.  Dropping a ball at the surface is
>> essentially putting an object into orbit with an initial velocity
>> equal to the rotational speed at the latitude of the drop. The path
>> then would have to be an ellipse.

> xxein:  I'm starting to have trouble here.  The video says that once
> inside, gravity is equal in every direction.  I can't buy that.  If
> the whole mass was homogeneous, then I could.  But not for the empty
> shell scenario.
>
> That aside for the moment, if once inside, gravity is equal in all
> directions, - how could you expect a ball to drop?

> Then it depends on where you drill the hole also.  Pole (no lateral
> rotation) or equator (max lateral rotation).  Hollow below surface,
> homogeneous or mantle and core.
>
> IOW, I lost where we're at and disagree with the video.  ???  There's
> probably more.
>

Gravity is simply the vector summation of the mass around you, so once
inside, pick 1000 miles, then a slice of spherical earth 1000 is on one
side and another spherical slice 3000 miles is on the other, so you do
have a lot of gravity, not as much as the surface.


if you add air into the tunnel, everything changes.

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#529668

On Saturday, October 31, 2015 at 9:52:59 AM UTC-7, xxe...@att.net wrote:
> On Friday, October 30, 2015 at 11:21:53 PM UTC-4, Fabian Russell wrote:
> > On Fri, 30 Oct 2015 22:11:20 -0500, gilber34 wrote:
> > 
> > >>
> > >> Question: What shape does a tunnel have to be to allow a complete
> > >> passage?
> > > 
> > > 
> > > with or without air in the tunnel ?
> > > 
> > > with, prob a strange sprial
> > > 
> > > without .......
> > >
> > 
> > Let consider without air.  Dropping a ball at the surface is
> > essentially putting an object into orbit with an initial velocity
> > equal to the rotational speed at the latitude of the drop.
> > The path then would have to be an ellipse.
> 
> xxein:  I'm starting to have trouble here.  The video says that once inside,
> gravity is equal in every direction.  I can't buy that.  If the whole mass
> was homogeneous, then I could.  But not for the empty shell scenario.

  I haven't looked at Sam's video because I can read faster than they can talk. I'm trying to get Sam to link to text-based sources instead of cartoons.

  The usual derivation is to consider the Earth as a nested set of practically infinitesimally thin (an atom thick is plenty close) shells- it's each shell you're to consider homogenous, not all the shells as a group.

  From outside, such a shell's gravitational field is identical to that of an equivalent (point) mass located at the center of the shell, just like a solid planet.

  Once you pass through a hole into the interior, you have to divide up the entire shell into as many small segments as you have computational capacity to handle because some of it is now attracting from above you. Compute the gravitational pull of each element, noting that there are a relative few that attract strongly just above you but a lot more farther away in all other directions that attract less strongly per inverse square. Taken together they all sum neatly to zero for all points within the shell.

  See, a homogenous shell generates a spherical surface of constant gravitational potential seen from outside; its geometric and gravitational centers coincide.

  If the shell is not homogenous (say one half is glass and the other is tungsten), the center of the gravitational field it generates won't be at the geometric center of the physical sphere any. IOW when you stand on it, gravity won't point straight down unless you're at a pole. If a hole opens under you, you fall at an angle to the surface (except at a pole).

  If you're falling straight into a hole centered on the glass hemisphere the center of the equipotential surface is farther away than if the shell were homogenous, so when you watch the edge of the hole whiz by, you're still accelerating downward. Once you pass the radius of the equipotential generated by the inhomogenous sphere you stop accelerating and coast.

> That aside for the moment, if once inside, gravity is equal in all
> directions, - how could you expect a ball to drop?

  In the case of the real Earth, all of the mass inside any shell you cross will still attract. In the Hollow Earth case, you have whatever momentum you got from falling in in the first place but it stops changing as you pass into the shell- you stop accelerating.

> Then it depends on where you drill the hole also.  Pole (no lateral rotation)
> or equator (max lateral rotation).

  For the pole, straight down through the center.

  At the equator, in a line that doesn't pass through the center.

  At the equator, your velocity has a radial component proportional to release height above the shell and a horizontal component due to rotation as the Earth rotates and drags you with it. Once released the rotation component stops changing.

>  Hollow below surface, homogeneous or mantle and core.

  Doesn't matter unless your shell is inhomogenous locally as long as it's homogenous globally. Say there's a huge chunk of basalt to your left in the granite shell you're falling through. You would fall in at a slight angle to the physical surface, but the chunk's local variation is still cancelled out by other chunks distributed throughout the shell (that's how you get a chunky yet homogenous shell).

> IOW, I lost where we're at and disagree with the video.  ???  There's
> probably more.

  Okay.


  Mark L. Fergerson

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#529717

On Sun, 01 Nov 2015 04:11:33 -0800, nuny@bid.nes wrote:

> 
>   I haven't looked at Sam's video because I can read faster than they can talk.
>

That is the ultimate critique and condemnation of the video medium.
For conveying information, it is inefficiency in the extreme.

Consider a 1 hour long video.  At current technology this represents
about 500 megabytes of encoding.

The same information contained in a text-based source would be only
10-20 kilobytes (uncompressed), but if we include ample graphics the
total would increase to the still paltry 5-10 megabytes.  Furthermore,
it wouldn't take 1 solid hour to digest the same material but more like
5-10 minutes.

As an instructional tool, video is a joke.

There are times when the video medium is desirable, such as viewing
historical footage or animated digital graphics, but such material
can never actually stand alone and must only be a supplement to
a text-based source.

But regarding text, the world still fails to realize the possibilities.
Unicode characters for mathematics, for example, are rarely encountered
and MathML in web sites is scarce as well.  These methods have been
present for many years but, for some reason, remain largely unknown.

In conclusion, video should be entirely abandoned in favor of rich
text sources, that is, text formats that utilize modern character
encodings and that contain embedded multimedia material as a supplement.

Instead of YouTube there should be YouRichText (trite, but one gets
the idea).

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#529350

Sam Wormley <swormley1@gmail.com> wrote:
> What if the Earth were Hollow?
>> https://www.youtube.com/watch?v=jN-FfJKgis8

How many more times are you going to reapeat this, spamming shit head?


-- 
Jim Pennino

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#529475

On Friday, October 30, 2015 at 6:32:47 PM UTC-7, Sam Wormley wrote:
> What if the Earth were Hollow?
> > https://www.youtube.com/watch?v=jN-FfJKgis8
> 
>    What if there were a tunnel through the middle of the earth and the
>    jimp jumped in?
> 
> -- 
> 
> sci.physics is an unmoderated newsgroup dedicated
> to the discussion of physics, news from the physics
> community, and physics-related social issues.

Sounds like HG Wells.Good science tells its the last place to find the vacuum .However it has atoms with great space between particles.There is more oif nothing in the quantum realm. TreBert

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#529556

On Fri, 30 Oct 2015 20:32:44 -0500, Sam Wormley wrote:

> What if the Earth were Hollow?
>> https://www.youtube.com/watch?v=jN-FfJKgis8
> 
>    What if there were a tunnel through the middle of the earth and the
>    jimp jumped in?

Unless it was precisely from pole to pole, he'd eventually hit the eastern 
wall of the hold and slide the rest of the say down.

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#529584

On 10/31/15 6:17 PM, Lofty Goat wrote:
> On Fri, 30 Oct 2015 20:32:44 -0500, Sam Wormley wrote:
>
>> What if the Earth were Hollow?
>>> https://www.youtube.com/watch?v=jN-FfJKgis8
>>
>>     What if there were a tunnel through the middle of the earth and the
>>     jimp jumped in?
>
> Unless it was precisely from pole to pole, he'd eventually hit the eastern
> wall of the hold and slide the rest of the say down.
>

   Ouch -- that's a lot of friction for the jimp to endure.


-- 

sci.physics is an unmoderated newsgroup dedicated
to the discussion of physics, news from the physics
community, and physics-related social issues.

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#529786

On Friday, October 30, 2015 at 6:32:47 PM UTC-7, Sam Wormley wrote:
> What if the Earth were Hollow?
> > https://www.youtube.com/watch?v=jN-FfJKgis8
> 
>    What if there were a tunnel through the middle of the earth and the
>    jimp jumped in?
> 
> -- 
> 
> sci.physics is an unmoderated newsgroup dedicated
> to the discussion of physics, news from the physics
> community, and physics-related social issues.

If earth had a hollow core it would have continual lightning .Think capasitor TreBert

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