Groups > sci.physics.relativity > #392521

Re: AC Gravity.

From	HGW <hw@....>
Newsgroups	sci.physics.relativity
Subject	Re: AC Gravity.
Date	2016-09-16 12:04 +1000
Organization	Aioe.org NNTP Server
Message-ID	<nrfjva$16lt$1@gioia.aioe.org> (permalink)
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On 16/09/16 02:51, Tom Roberts wrote:
> On 9/15/16 9/15/16 - 12:27 AM, Poutnik wrote:
>> Dne 15/09/2016 v 00:04 Tom Roberts napsal(a):
>>> What you propose merely generates a time-varying gravitational field;
>>> that's
>>> rather easy to detect. But it is NOT the self-propagating
>>> gravitational waves of
>>> GR, which are VASTLY more difficult to detect.
>>>
>>>     BTW "gravity waves" are something completely different --
>>>     that is the term used for waves of matter driven by gravity;
>>>     examples are waves on the surface of water, salinity waves in
>>>     the ocean, etc.
>>>
>>> Your setup will indeed emit gravitational waves, albeit extremely
>>> weakly. To
>>> identify them as such the detector needs to be several wavelengths
>>> away from the
>>> source; for 10,000 RPM it would need to be millions of kilometers
>>> away. Hopeless.
>>
>> If not waves, how would be called the periodic changes of gravity as
>> above
>> in sense of being dual periodicity phenomena, as gravity changes
>> do not propagate at infinite speed ?
>
> It is a time-varying gravitational field, as I said.
>
>
>> As such "time-varying gravitational field",
>> calls for a wave equation and a wave function the solution..
>
> No. Newtonian mechanics has no wave equation for gravitation, but can
> easily and accurately model this sort of experiment, using its
> instantaneous gravitational field.

I don't think Newton thought much about the speed of gravitational 
waves...but whether or not a static field acts instantly on a moving 
object is an interesting question.
But I'm sure Newton's theory does predict that any disturbance in a 
field would produce a traveling wave. How would it not?

>      A wave equation will have a Green's function that involves
>      retarded potentials expressed in terms of BOTH distance and
>      time delay, as in electrodynamics (see "Lienard-Wiechert
>      potentials" which are a Green's function for electrodynamics).
>      The green's function for Newtonian gravity does not involve
>      time at all, and there are no wavelike solutions.

They simply didn't consider the possibility. At that time, there was no 
known way that a gravity field could experience a sudden massive 
disturbance.

> The difference between a time-varying field and a wave is that the wave
> is self-propagating over large distances but time-varying fields are
> tied to the (time-varying) source and are restricted to a region nearby.

'Nearby' is not a scientific term. The relevant law says there is no 
limit..The amplitude just approaches 1/infinity, in this case quite rapidly.

> Light waves traverse the galaxy long after their source has been
> extinguished, but the E field from isolated charges does not leave the
> laboratory and vanishes when the charges are neutralized.-

You are comparing static fields with alternating ones. If the charge 
oscillates backwards and forwards, its field will do the same and behave 
like a spherical traveling wave. That more or less how a broadcasting 
antenna operates.

Consider what happens when a SN occurs. Beforehand, there was a static 
gravitional field. Mass suddenly disappears into radiation and the field 
collapses. I would be very surprised if such a disturbance would not 
result in massive traveling waves of broad spectrum in all directions.

> As I said above, the SELF-PROPAGATING gravitational waves of GR are
> quite different. As in electrodynamics, there are near-field effects and
> far-field effects (these involve different approximations);
> gravitational waves are far-field only, but this experiment is
> near-field only (as is the Japanese experiment Wilson mentioned).

Well, nobody wants to set of uranium bombs in their laboratory so it is 
pretty hard to experiment with 'far-field' effects.
But I cannot see any real difference in the two principles or the two 
waves..

> Tom Roberts

--

Thread

AC Gravity. HGW <hw@....> - 2016-09-14 18:01 +1000
  Re: AC Gravity. Tom Roberts <tjroberts137@sbcglobal.net> - 2016-09-14 17:04 -0500
    Re: AC Gravity. Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-09-14 15:22 -0700
      Re: AC Gravity. HGW <hw@....> - 2016-09-15 09:53 +1000
        Re: AC Gravity. Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-09-14 19:10 -0700
        Re: AC Gravity. Tom Roberts <tjroberts137@sbcglobal.net> - 2016-09-15 00:01 -0500
          Re: AC Gravity. HGW <hw@....> - 2016-09-15 17:47 +1000
        Re: AC Gravity. moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-09-15 15:27 +0000
          Re: AC Gravity. "HGWilson, DSc." <hgw@....> - 2016-09-16 06:44 +1000
            Re: AC Gravity. Tom Roberts <tjroberts137@sbcglobal.net> - 2016-09-15 17:16 -0500
              Re: AC Gravity. HGW <hw@....> - 2016-09-16 11:20 +1000
            Re: AC Gravity. moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-09-15 22:54 +0000
              Re: AC Gravity. HGW <hw@....> - 2016-09-16 11:27 +1000
                Re: AC Gravity. moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-09-16 03:58 +0000
                Re: AC Gravity. "HGWilson, DSc." <hgw@....> - 2016-09-17 04:58 +1000
                Re: AC Gravity. Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-09-16 12:18 -0700
                Re: AC Gravity. "HGWilson, DSc." <hgw@....> - 2016-09-18 05:42 +1000
                Re: AC Gravity. Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-09-17 21:08 -0700
                Re: AC Gravity. HGW <hw@....> - 2016-09-18 20:09 +1000
                Re: AC Gravity. moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-09-18 12:57 +0000
                Re: AC Gravity. HGW <hw@....> - 2016-09-19 15:11 +1000
                Re: AC Gravity. moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-09-19 14:37 +0000
                Re: AC Gravity. "HGWilson, DSc." <hgw@....> - 2016-09-20 04:44 +1000
                Re: AC Gravity. moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-09-19 21:47 +0000
                Re: AC Gravity. Odd Bodkin <bodkinodd@gmail.com> - 2016-09-19 11:16 -0500
                Re: AC Gravity. Tom Roberts <tjroberts137@sbcglobal.net> - 2016-09-19 13:22 -0500
                Re: AC Gravity. "HGWilson, DSc." <hgw@....> - 2016-09-20 04:58 +1000
                Re: AC Gravity. Tom Roberts <tjroberts137@sbcglobal.net> - 2016-09-19 22:24 -0500
                Re: AC Gravity. HGW <hw@....> - 2016-09-21 20:04 +1000
                Re: AC Gravity. Odd Bodkin <bodkinodd@gmail.com> - 2016-09-20 07:20 -0500
                Re: AC Gravity. HGW <hw@....> - 2016-09-21 20:10 +1000
                Re: AC Gravity. Odd Bodkin <bodkinodd@gmail.com> - 2016-09-21 07:59 -0500
                Re: AC Gravity. "Paul B. Andersen" <relativity@paulba.no> - 2016-09-22 13:57 +0200
                Re: AC Gravity. Odd Bodkin <bodkinodd@gmail.com> - 2016-09-19 09:51 -0500
                Re: AC Gravity. Odd Bodkin <bodkinodd@gmail.com> - 2016-09-19 09:32 -0500
                Re: AC Gravity. "HGWilson, DSc." <hgw@....> - 2016-09-20 04:52 +1000
                Re: AC Gravity. Tom Roberts <tjroberts137@sbcglobal.net> - 2016-09-19 22:35 -0500
                Re: AC Gravity. HGW <hw@....> - 2016-09-21 20:08 +1000
                Re: AC Gravity. Odd Bodkin <bodkinodd@gmail.com> - 2016-09-20 07:18 -0500
                Re: AC Gravity. Odd Bodkin <bodkinodd@gmail.com> - 2016-09-16 14:22 -0500
                Re: AC Gravity. moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-09-16 20:55 +0000
                Re: AC Gravity. "HGWilson, DSc." <hgw@....> - 2016-09-18 05:40 +1000
                Re: AC Gravity. pnalsing@gmail.com - 2016-09-17 17:59 -0700
                Re: AC Gravity. moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-09-18 03:18 +0000
    Re: AC Gravity. Poutnik <poutnik4nntp@gmail.com> - 2016-09-15 07:27 +0200
      Re: AC Gravity. HGW <hw@....> - 2016-09-15 17:50 +1000
        Re: AC Gravity. Poutnik <poutnik4nntp@gmail.com> - 2016-09-16 07:06 +0200
        Re: AC Gravity. Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-09-16 00:54 -0700
          Re: AC Gravity. RichD <r_delaney2001@yahoo.com> - 2016-09-30 09:44 -0700
      Re: AC Gravity. Tom Roberts <tjroberts137@sbcglobal.net> - 2016-09-15 11:51 -0500
        Re: AC Gravity. HGW <hw@....> - 2016-09-16 12:04 +1000
          Re: AC Gravity. Tom Roberts <tjroberts137@sbcglobal.net> - 2016-09-16 22:17 -0500
            Re: AC Gravity. "HGWilson, DSc." <hgw@....> - 2016-09-18 06:27 +1000
              Re: AC Gravity. Tom Roberts <tjroberts137@sbcglobal.net> - 2016-09-20 19:47 -0500
                Re: AC Gravity. HGW <hw@....> - 2016-09-21 19:48 +1000
        Re: AC Gravity. Poutnik <poutnik4nntp@gmail.com> - 2016-09-16 07:21 +0200
          Re: AC Gravity. jaymoseley@hotmail.com - 2016-09-22 01:33 -0700
            Re: AC Gravity. Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-09-22 04:50 -0700
              Re: AC Gravity. jaymoseley@hotmail.com - 2016-09-22 05:53 -0700
                Re: AC Gravity. Gary Harnagel <hitlong@yahoo.com> - 2016-09-22 14:43 -0700
                Re: AC Gravity. HGW <hw@....> - 2016-09-23 08:18 +1000
                Re: AC Gravity. Gary Harnagel <hitlong@yahoo.com> - 2016-09-22 15:39 -0700
                Re: AC Gravity. Odd Bodkin <bodkinodd@gmail.com> - 2016-09-23 07:01 -0500
                Re: AC Gravity. jaymoseley@hotmail.com - 2016-09-23 01:12 -0700
                Re: AC Gravity. Ned Latham <nedlatham@woden.valhalla.oz> - 2016-09-23 09:46 +0000
                Re: AC Gravity. jaymoseley@hotmail.com - 2016-09-24 05:37 -0700
                Re: AC Gravity. Gary Harnagel <hitlong@yahoo.com> - 2016-09-24 07:32 -0700
                Re: AC Gravity. jaymoseley@hotmail.com - 2016-09-25 06:35 -0700
                Re: AC Gravity. Gary Harnagel <hitlong@yahoo.com> - 2016-09-25 10:58 -0700
                Re: AC Gravity. jaymoseley@hotmail.com - 2016-09-26 02:37 -0700
                Re: AC Gravity. Gary Harnagel <hitlong@yahoo.com> - 2016-09-26 04:32 -0700
                Re: AC Gravity. Odd Bodkin <bodkinodd@gmail.com> - 2016-09-24 13:05 -0500
                Re: AC Gravity. jaymoseley@hotmail.com - 2016-09-25 06:00 -0700
                Re: AC Gravity. Odd Bodkin <bodkinodd@gmail.com> - 2016-09-25 17:15 -0500
                Re: AC Gravity. jaymoseley@hotmail.com - 2016-09-26 02:54 -0700
                Re: AC Gravity. Odd Bodkin <bodkinodd@gmail.com> - 2016-09-26 08:29 -0500
                Re: AC Gravity. Gary Harnagel <hitlong@yahoo.com> - 2016-09-23 05:34 -0700
                Re: AC Gravity. jaymoseley@hotmail.com - 2016-09-26 04:10 -0700
                Re: AC Gravity. Gary Harnagel <hitlong@yahoo.com> - 2016-09-26 05:30 -0700
                Re: AC Gravity. mlwozniak@wp.pl - 2016-09-26 06:38 -0700
                Re: AC Gravity. jaymoseley@hotmail.com - 2016-09-27 05:11 -0700
                Re: AC Gravity. Gary Harnagel <hitlong@yahoo.com> - 2016-09-27 08:47 -0700
                Re: AC Gravity. jaymoseley@hotmail.com - 2016-09-28 10:16 -0700
                Re: AC Gravity. Gary Harnagel <hitlong@yahoo.com> - 2016-09-28 14:03 -0700
                Re: AC Gravity. jaymoseley@hotmail.com - 2016-09-30 05:33 -0700
                Re: AC Gravity. Gary Harnagel <hitlong@yahoo.com> - 2016-09-30 06:41 -0700
                Re: AC Gravity. jaymoseley@hotmail.com - 2016-10-02 02:39 -0700
                Re: AC Gravity. Gary Harnagel <hitlong@yahoo.com> - 2016-10-02 05:26 -0700
                Re: AC Gravity. jaymoseley@hotmail.com - 2016-10-05 04:54 -0700
                Re: AC Gravity. Gary Harnagel <hitlong@yahoo.com> - 2016-10-06 06:59 -0700
                Re: AC Gravity. jaymoseley@hotmail.com - 2016-10-09 05:25 -0700
                Re: AC Gravity. Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-10-09 06:06 -0700
                Re: AC Gravity. Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2016-10-09 10:06 -0700
                Re: AC Gravity. jaymoseley@hotmail.com - 2016-10-12 08:28 -0700
                Re: AC Gravity. Odd Bodkin <bodkinodd@gmail.com> - 2016-09-26 08:32 -0500
  Re: AC Gravity. "Paul B. Andersen" <relativity@paulba.no> - 2016-09-15 15:38 +0200
    Re: AC Gravity. "HGWilson, DSc." <hgw@....> - 2016-09-16 06:48 +1000

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