Re: [Vo]:cannon balls and curling stones

[H LV]

On Wed, Jan 22, 2020 at 4:46 PM H LV  wrote:

>
>
> On Mon, Jan 13, 2020 at 12:21 PM H LV  wrote:
>
>>
>>
>> On Mon, Jan 13, 2020 at 10:15 AM H LV  wrote:
>>
>>> This is an illustration from Newton's Principia of his famous cannon
>>> thought experiment. It shows how a cannonball fired horizontally from a
>>> mountain top (assuming no air resistance) will orbit the Earth without
>>> falling to the ground if it is fired with sufficient speed.
>>> https://imgur.com/gallery/dzSLWaa
>>>
>>> Now imagine an ice covered planet which is perfectly smooth, with no
>>> mountains or valleys. On the surface rests a curling stone of a given
>>> _weight_. If the curling stone is propelled horizontally with sufficient
>>> speed it will orbit the planet while sliding over the surface. At this
>>> velocity it will be in free fall so its weight will be effectively zero.
>>> The question is does the weight of the curling stone gradually increase as
>>> the horizontal velocity gradually decreases or does the curling stone
>>> resume its full weight for any velocity less than the orbital velocity?
>>>
>>> Harry
>>>
>>
>> To answer my own question... the classical prediction is the weight of
>> the stone should increase, because the centrifugal force is decreasing in
>> the frame of reference of the stone. However, if gravity in General
>> Relativity is not a force then a corresponding a centrifugal force does not
>> arise. Therefore, if GR is true, the weight of the stone should jump to its
>> full weight for any value less than the orbital speed. (Actually I think
>> there is argument to be made that even Newtonian gravity is not a force and
>> is just an acceleration).
>> Harry
>>
>
> Just a follow up. Since a body sitting at the equator is moving faster
> than the same body near the pole it should weigh less due to the greater
> centrifugal force caused by the Earth's rotation. Until  recently I don't
> think anyone had tried to measure this predicted effect and it was just
> taken for granted to be true. (There have been tests on the equivalence of
> inertial mass and gravitational mass but this is a different test).
> However arguments between Flat-Earthers and Anti-Flat earthers have
> resulted in amateur empirical investigations of the matter. Flat Earther's
> contend the weight should be constant since they hold the earth is flat and
> does not rotate.  The results so far seem to be open to interpretation. I
> am not a Flat- Earther but it is interersting how this fringe community has
> turned it into an empirical question.
>
> Harry
>


So it seems Eotvos in the first decade of the 1900s used Earth's rotation
and centrifugal force to explain observed differences in some weights on
ships moving in opposite directions. Until now I was only familiar with his
work on the equivalence of gravitational and inertial mass in 1889. see
https://en.wikipedia.org/wiki/E%C3%B6tv%C3%B6s_effect

[Vo]:There is no dark matter. Instead, information has mass, physicist says

[Terry Blanton]

bigthink.com:
https://bigthink.com/surprising-science/dark-matter-theory

Re: [Vo]:cannon balls and curling stones

[Jürg Wyttenbach]

Unluckily the earth is not flat even in the curved sense as it is an 
ellipsoid with at least a delta north-south/east-west in radius of about 
10km.


Even more unluckily gravitation is not a constant it slightly depends on 
the density of matter. And last but not least gravity is a force and not 
just a curvature of space. From a mathematical point of view there is no 
difference between the two views as long as you do not believe that the 
gravity force is of purely central nature.
The idea of curvature emerged because physicist had no clue why a photon 
could be attracted by a mass. But all EM-mass interact with other EM 
mass what leads to the other erroneous picture of virtual particle 
background.
I you once understand why/how all mass is EM-mass, then you also will 
understand all mistakes of 100 year physics.


J.W.

PS: Who will construct this perfect cannon that is able to do a shot 
exactly along the horizon line? Not Boing...




Am 22.01.20 um 22:46 schrieb H LV:



On Mon, Jan 13, 2020 at 12:21 PM H LV > wrote:




On Mon, Jan 13, 2020 at 10:15 AM H LV mailto:hveeder...@gmail.com>> wrote:

This is an illustration from Newton's Principia of his famous
cannon thought experiment. It shows how a cannonball fired
horizontally from a mountain top (assuming no air resistance)
will orbit the Earth without falling to the ground if it is
fired with sufficient speed.
https://imgur.com/gallery/dzSLWaa

Now imagine an ice covered planet which is perfectly smooth,
with no mountains or valleys. On the surface rests a curling
stone of a given _weight_. If the curling stone is propelled
horizontally with sufficient speed it will orbit the planet
while sliding over the surface. At this velocity it will be in
free fall so its weight will be effectively zero. The question
is does the weight of the curling stone gradually increase as
the horizontal velocity gradually decreases or does the
curling stone resume its full weight for any velocity less
than the orbital velocity?

Harry


To answer my own question... the classical prediction is the
weight of the stone should increase, because the centrifugal force
is decreasing in the frame of reference of the stone. However, if
gravity in General Relativity is not a force then a corresponding
a centrifugal force does not arise. Therefore, if GR is true, the
weight of the stone should jump to its full weight for any value
less than the orbital speed. (Actually I think there is argument
to be made that even Newtonian gravity is not a force and is just
an acceleration).
Harry


Just a follow up. Since a body sitting at the equator is moving faster 
than the same body near the pole it should weigh less due to the 
greater centrifugal force caused by the Earth's rotation. Until  
recently I don't think anyone had tried to measure this predicted 
effect and it was just taken for granted to be true. (There have been 
tests on the equivalence of inertial mass and gravitational mass but 
this is a different test). However arguments between Flat-Earthers and 
Anti-Flat earthers have resulted in amateur empirical investigations 
of the matter. Flat Earther's contend the weight should be constant 
since they hold the earth is flat and does not rotate.  The results so 
far seem to be open to interpretation. I am not a Flat- Earther but it 
is interersting how this fringe community has turned it into an 
empirical question.


Harry



--
Jürg Wyttenbach
Bifangstr.22
8910 Affoltern a.A.
044 760 14 18
079 246 36 06

Re: [Vo]:cannon balls and curling stones

[H LV]

On Mon, Jan 13, 2020 at 12:21 PM H LV  wrote:

>
>
> On Mon, Jan 13, 2020 at 10:15 AM H LV  wrote:
>
>> This is an illustration from Newton's Principia of his famous cannon
>> thought experiment. It shows how a cannonball fired horizontally from a
>> mountain top (assuming no air resistance) will orbit the Earth without
>> falling to the ground if it is fired with sufficient speed.
>> https://imgur.com/gallery/dzSLWaa
>>
>> Now imagine an ice covered planet which is perfectly smooth, with no
>> mountains or valleys. On the surface rests a curling stone of a given
>> _weight_. If the curling stone is propelled horizontally with sufficient
>> speed it will orbit the planet while sliding over the surface. At this
>> velocity it will be in free fall so its weight will be effectively zero.
>> The question is does the weight of the curling stone gradually increase as
>> the horizontal velocity gradually decreases or does the curling stone
>> resume its full weight for any velocity less than the orbital velocity?
>>
>> Harry
>>
>
> To answer my own question... the classical prediction is the weight of the
> stone should increase, because the centrifugal force is decreasing in the
> frame of reference of the stone. However, if gravity in General Relativity
> is not a force then a corresponding a centrifugal force does not arise.
> Therefore, if GR is true, the weight of the stone should jump to its full
> weight for any value less than the orbital speed. (Actually I think there
> is argument to be made that even Newtonian gravity is not a force and is
> just an acceleration).
> Harry
>

Just a follow up. Since a body sitting at the equator is moving faster than
the same body near the pole it should weigh less due to the greater
centrifugal force caused by the Earth's rotation. Until  recently I don't
think anyone had tried to measure this predicted effect and it was just
taken for granted to be true. (There have been tests on the equivalence of
inertial mass and gravitational mass but this is a different test).
However arguments between Flat-Earthers and Anti-Flat earthers have
resulted in amateur empirical investigations of the matter. Flat Earther's
contend the weight should be constant since they hold the earth is flat and
does not rotate.  The results so far seem to be open to interpretation. I
am not a Flat- Earther but it is interersting how this fringe community has
turned it into an empirical question.

Harry