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Re: What has stopped rotating?

Subject	Re: What has stopped rotating?
Newsgroups	sci.physics.relativity
References	(11 earlier) <hqj9N.405963$YBDd.188445@fx09.ams4> <5ad12383-78bc-4393-b69d-c040cfe1b31an@googlegroups.com> <enO9N.248687$2E8a.137547@fx07.ams4> <acaab06b-6361-4920-b699-74a25e2ff641n@googlegroups.com> <3d42f256-a3c1-452a-a0a3-50fed470475an@googlegroups.com>
From	"Paul B. Andersen" <relativity@paulba.no>
Message-ID	<YbkaN.2$GEe7.0@fx06.ams4> (permalink)
Organization	Eweka Internet Services
Date	2023-12-01 13:22 +0100

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Den 30.11.2023 21:12, skrev patdolan:
>> On Wednesday, 29 November 2023 at 22:51:11 UTC+1, Paul B. Andersen wrote:
>>> Den 28.11.2023 20:53, skrev patdolan:
>>>> On Tuesday, November 28, 2023 at 2:38:09 AM UTC-8, Paul B. Andersen wrote:
>>>>>
>>>>> Second challenge:
>>>>> A long heavy pendulum is hanging under the ISS.
>>>>> A stable situation is that the pendulum is always
>>>>> pointing towards the centre of the Earth.
>>>>>
>>>>> Which forces are acting on the pendulum mass?

>>>
>>>> Neither the sun's gravitational field nor the earth's gravitational field exerts a force on the pendulum you discribe. Because the pendulum is in free fall around both. Only Mach's mysterious trans-universe space-brace field acts on the pendulum and the ISS gyroscope.

>>> According to Newton:
>>> 
>>> The gravitational force on any object with mass m is
>>> always GMm/r² pointing towards the centre of the Earth.
>>> If the object is free falling, the gravitational
>>> (coordinate) acceleration will be GM/r², pointing
>>> towards the centre of the Earth.
>>> 
>>> The CG of ISS + pendulum is moving in circular orbit,
>>> which means that the acceleration is perpendicular to
>>> the velocity, so the acceleration ω²⋅r₀ is the centripetal
>>> acceleration which make the ISS move in circular orbit.
>>> The centripetal acceleration is equal to the gravitational
>>> acceleration:
>>>    ω²⋅r₀ = GM/r₀²      (1)
>>> where ω is the angular velocity off the ISS, and r₀ is the
>>> distance from the CG of ISS+pendulum to the centre of the Earth.
>>> 
>>> Equation (1) say that an object with angular velocity ω
>>> must have a distance from the centre of the Earth:
>>>  r₀  = ∛(GM/ω²) to make the centripetal acceleration equal
>>> to the gravitational acceleration.
>>> 
>>> The pendulum mass m is not free falling because:
>>> 
>>> Its distance to the centre of the Earth is:
>>>  r₁ = r₀-L where L is the length of the pendulum.
>>> So r₁ < r₀, but the angular velocity of m is the same ω,
>>> and  r₁ <  ∛(GM/ω²), which means that:
>>>     ω²⋅r₁ < GM/r₁²      (2)
>>> The centripetal acceleration is smaller than the gravitational
>>> acceleration, so the force the string is acting on
>>> the pendulum mass is F₁ = m⋅(GM/r₁²-ω²⋅r₁)
>>> 
>>> ---
>>> 
>>> An interesting point is that you could have a pendulum
>>> on the other side of the ISS, pointing outwards from the
>>> centre of the Earth.
>>> The force the string is acting on the mass m is:
>>> F₂ = m⋅(ω²⋅r₂-GM/r₂²)
>>> 
>>> F₁ and F₂ are called tidal forces.
>>> (It's a tidal bulge on both sides of the Earth)


No comment, Pat?

You claimed that there were no forces on the pendulum.
I showed you that you could have a pendulum on both
sides of the ISS, and the pendulum strings will exert
forces on the pendulum masses, acting towards the ISS.

And GR predicts the same!

Do you realise that you were wrong, but won't admit it,
so you ignore my post, hoping that nobody will notice
your failure.

-- 
Paul

https://paulba.no/

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Re: What has stopped rotating? patdolan <patdolan@comcast.net> - 2023-11-23 20:14 -0800
  Re: What has stopped rotating? patdolan <patdolan@comcast.net> - 2023-11-23 20:26 -0800
  Re: What has stopped rotating? Volney <volney@invalid.invalid> - 2023-11-23 23:29 -0500
    Re: What has stopped rotating? patdolan <patdolan@comcast.net> - 2023-11-23 20:36 -0800
      Re: What has stopped rotating? patdolan <patdolan@comcast.net> - 2023-11-23 20:59 -0800
        Re: What has stopped rotating? patdolan <patdolan@comcast.net> - 2023-11-23 21:16 -0800
          Re: What has stopped rotating? patdolan <patdolan@comcast.net> - 2023-11-23 22:16 -0800
          Re: What has stopped rotating? Volney <volney@invalid.invalid> - 2023-11-27 02:13 -0500
            Re: What has stopped rotating? Maciej Wozniak <maluwozniak@gmail.com> - 2023-11-26 23:48 -0800
            Re: What has stopped rotating? patdolan <patdolan@comcast.net> - 2023-11-27 11:36 -0800
              Re: What has stopped rotating? Volney <volney@invalid.invalid> - 2023-11-29 23:36 -0500
                Re: What has stopped rotating? patdolan <patdolan@comcast.net> - 2023-11-29 21:03 -0800
                Re: What has stopped rotating? Tom Roberts <tjoberts137@sbcglobal.net> - 2023-11-30 12:22 -0600
                Re: What has stopped rotating? patdolan <patdolan@comcast.net> - 2023-11-30 12:16 -0800
                Re: What has stopped rotating? patdolan <patdolan@comcast.net> - 2023-12-02 20:02 -0800
            Re: What has stopped rotating? Dearl Numerov Hasbulatov <veav@rvdlevom.lr> - 2023-11-27 20:11 +0000
      Re: What has stopped rotating? Volney <volney@invalid.invalid> - 2023-11-24 13:17 -0500
        Re: What has stopped rotating? Yoslan Beknazar Yuzbashev <vasv@eohlsyeu.vn> - 2023-11-24 18:32 +0000
          Re: What has stopped rotating? Physfitfreak <Physfitfreak@gmail.com> - 2023-11-24 12:59 -0600
            Re: What has stopped rotating? Duan Turkestanov <nank@tautkvtd.nd> - 2023-11-24 20:40 +0000
        Re: What has stopped rotating? patdolan <patdolan@comcast.net> - 2023-11-24 13:18 -0800
        Re: What has stopped rotating? Baldemar Baburkin <bled@ebabrrkd.ad> - 2023-11-25 21:31 +0000
          Re: What has stopped rotating? Physfitfreak <Physfitfreak@gmail.com> - 2023-11-25 20:26 -0600
            Re: What has stopped rotating? Russell Baibikov Dobrohotov <rlia@lvlsbkrs.ia> - 2023-11-26 11:50 +0000
            Re: What has stopped rotating? The Starmaker <starmaker@ix.netcom.com> - 2023-11-26 13:30 -0800
              Re: What has stopped rotating? Physfitfreak <Physfitfreak@gmail.com> - 2023-11-26 15:43 -0600
                Re: What has stopped rotating? The Starmaker <starmaker@ix.netcom.com> - 2023-11-26 14:09 -0800
                Re: What has stopped rotating? Physfitfreak <Physfitfreak@gmail.com> - 2023-11-26 19:27 -0600
                Re: What has stopped rotating? The Starmaker <starmaker@ix.netcom.com> - 2023-12-02 12:17 -0800
                Re: What has stopped rotating? Physfitfreak <Physfitfreak@gmail.com> - 2023-12-02 18:19 -0600
                Re: What has stopped rotating? The Starmaker <starmaker@ix.netcom.com> - 2023-12-02 19:59 -0800
                Re: What has stopped rotating? Physfitfreak <Physfitfreak@gmail.com> - 2023-12-02 22:29 -0600
                Re: What has stopped rotating? The Starmaker <starmaker@ix.netcom.com> - 2023-12-02 22:01 -0800
                Re: What has stopped rotating? Physfitfreak <Physfitfreak@gmail.com> - 2023-12-03 00:24 -0600
                Re: What has stopped rotating? Renato Tsval Dobrushkin <olta@snosnavl.vl> - 2023-12-03 11:25 +0000
                Re: What has stopped rotating? Physfitfreak <Physfitfreak@gmail.com> - 2023-12-03 14:34 -0600
                Re: What has stopped rotating? Fabian Tzaregorodtsev Babayan <izab@sogfafrz.tb> - 2023-12-04 15:57 +0000
                Re: What has stopped rotating? The Starmaker <starmaker@ix.netcom.com> - 2023-12-03 14:21 -0800
                Re: What has stopped rotating? Physfitfreak <Physfitfreak@gmail.com> - 2023-12-03 19:38 -0600
                Re: What has stopped rotating? The Starmaker <starmaker@ix.netcom.com> - 2023-12-03 21:03 -0800
                Re: What has stopped rotating? Volney <volney@invalid.invalid> - 2023-12-04 14:40 -0500
                Re: What has stopped rotating? Brennon Bestuzhev Ryumin <znhb@bseeuntz.rn> - 2023-12-04 21:48 +0000
                Re: What has stopped rotating? Physfitfreak <Physfitfreak@gmail.com> - 2023-12-04 18:40 -0600
    Re: What has stopped rotating? Buck Musatov <sckv@cuvvtsmb.cs> - 2023-11-24 14:15 +0000
    Re: What has stopped rotating? Richard Hertz <hertz778@gmail.com> - 2023-11-24 09:37 -0800
      Re: What has stopped rotating? Richard Hertz <hertz778@gmail.com> - 2023-11-24 14:25 -0800
        Re: What has stopped rotating? "Paul B. Andersen" <relativity@paulba.no> - 2023-11-27 20:48 +0100
          Re: What has stopped rotating? patdolan <patdolan@comcast.net> - 2023-11-27 11:50 -0800
            Re: What has stopped rotating? "Paul B. Andersen" <relativity@paulba.no> - 2023-11-28 11:40 +0100
              Re: What has stopped rotating? patdolan <patdolan@comcast.net> - 2023-11-28 11:53 -0800
                Re: What has stopped rotating? "Paul B. Andersen" <relativity@paulba.no> - 2023-11-29 22:53 +0100
                Re: What has stopped rotating? Maciej Wozniak <maluwozniak@gmail.com> - 2023-11-30 11:00 -0800
                Re: What has stopped rotating? patdolan <patdolan@comcast.net> - 2023-11-30 12:12 -0800
                Re: What has stopped rotating? "Paul B. Andersen" <relativity@paulba.no> - 2023-12-01 13:22 +0100
                Re: What has stopped rotating? patdolan <patdolan@comcast.net> - 2023-12-01 18:34 -0800
                Re: What has stopped rotating? "Paul B. Andersen" <relativity@paulba.no> - 2023-12-02 12:39 +0100
                Re: What has stopped rotating? The Starmaker <starmaker@ix.netcom.com> - 2023-12-02 11:00 -0800
                Re: What has stopped rotating? "mitchr...@gmail.com" <mitchrae3323@gmail.com> - 2023-12-02 11:08 -0800
                Re: What has stopped rotating? Prokaryotic Capase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2023-12-02 15:23 -0800
                Re: What has stopped rotating? Physfitfreak <Physfitfreak@gmail.com> - 2023-12-02 18:23 -0600
                Re: What has stopped rotating? The Starmaker <starmaker@ix.netcom.com> - 2023-12-02 20:02 -0800
                Re: What has stopped rotating? Physfitfreak <Physfitfreak@gmail.com> - 2023-12-02 22:35 -0600
                Re: What has stopped rotating? Maciej Wozniak <maluwozniak@gmail.com> - 2023-12-04 18:27 -0800
  Re: What has stopped rotating? Emilio Marchanukov <kmlo@iommueml.om> - 2023-11-24 16:26 +0000
  Re: What has stopped rotating? The Starmaker <starmaker@ix.netcom.com> - 2023-11-24 10:47 -0800
  Re: What has stopped rotating? The Starmaker <starmaker@ix.netcom.com> - 2023-11-24 10:49 -0800

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