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Re: energy and mass

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On Thu, 12 Feb 2026 14:55:27 +0100, Thomas 'PointedEars' Lahn
<PointedEars@web.de> wrote:

>john larkin wrote:
>> [...] (Stefan Ram) wrote:
>>> john larkin <jl@glen--canyon.com> wrote or quoted:
>>>> Two gamma rays (zero mass total) can collide to produce a particle
>>>> pair (which has mass.)
>>>
>>> [irrelevant and misleading/wrong calculation]
>>
>> The gamma rays had no gravitational effect on the rest of the mass in
>> the universe,
>
>Wrong.
>
>> up until the instant that they collided
>                            ^^^^^^^^^^^^^
>Nonsense.
>
>> to form a particle pair.
>
>Wrong.
>
>> Then a gravitational object magically appeared.
>
>Wrong.  Since the postulation and confirmation of general relativity we know
>that gravitational effects are not (solely) based on mass, but rather more
>generally on the density of stress, energy, and momentum:
>
>The Einstein Field Equations are in units where c = 1
>
>  G_ab + Lambda g_ab = 8pi G T_ab,
>
>where
>
>  G_ab = R_ab - 1/2 R g_ab
>
>is (a component of) the Einstein tensor, R_ab is the Ricci curvature tensor,
>g_ab is the metric tensor, R = g^ab R_ab is the Ricci curvature scalar,
>Lambda is the cosmological constant, and T_ab is the
>(stress--)energy--momentum tensor.
>
>Gravitional effects are understood (in GR) as a consequence of the curvature
>of spacetime which is described by the quantities on the left-hand side of
>the equations.
>
>The energy--momentum tensor of a 1+3-dimensional spacetime has 16
>components, but it is antisymmetric so only 10 of them are unique.  Anyhow,
>the time--time component is proportional to the energy density which is at
>relative rest is proportional to the mass density:
>
>  T_00 ~ rho_E ~ dE_0/dV = c^2 dm/dV = c^2 rho_m.
>
>> Does't that create a spherical, symmetric, expanding bubble of gravity?
>
>It does not.
>
>> I'm just an engineer,
>
>IOW: This is way over your head.
>
>As an engineer, though, you should appreciate the requirement to agree and
>conform to standards.  That includes network standards which you keep
>violating by your address munging:
>
><https://www.rfc-editor.org/rfc/rfc5536.html#section-3.1.2>
>
>> but I think this is real.
>
>It is not.  You are arguing from your ignorance.
>
>> People say it's not technically possible,
>
>It is possible, just very difficult:
>
>The total energy of both photons has at least to be equal to the sum of the
>rest energies of the particle and antiparticle.
>
>You would have to separate the particle and the antiparticle to prevent them
>from annihilating again, which means that the total energy of both photons
>has to be much larger than the sum of the rest energies of the particle and
>the antiparticle.  You need energy for the magnetic fields that keep them
>separated.
>
>> or that the efffect is too small to worry about,
>
>A single electron is not very useful, indeed, and you need more energy to
>produce it this way than it could do usable work because it needs kinetic
>energy *and* rest energy E_0 = m_e c^2.
>
>> or some other excuse for not saying that it could happen.
>> 
>> There is an electrical equivalent. A metal sphere could suddenly
>> become charged,
>
>No, the total electric charge is conserved.  What happens in "charging" is
>that electric charge is added from or removed to somewhere else.
>
>Electric charge can also be "induced" by bringing an electrically charge in
>the vicinity of an electrically neutral object.  Then the carriers of
>electric charge in the formerly neutral object arrange themselves such that
>the distribution of electric charge is no longer uniform:
>
>  .---------.     ,---------.
>  : (+) (-) :     : (+) (-) :
>  : (-) (+) :     : (+) (-) :
>  : (+) (-) :     : (+) (-) :
>  : (-) (+) :     : (+) (-) :
>  : (+) (-) :     : (+) (-) :
>  : (-) (+) :     : (+) (-) :
>  : (+) (-) :     : (+) (-) :
>  : (-) (+) :     : (+) (-) :
>  : (+) (-) :     : (+) (-) :
>  : (-) (+) :     : (+) (-) :
>  '---------'     '---------'
>
>  Some time later:
>
>  .---------.     ,---------.
>  : (+) (-) :     : (+) (-) :
>  : (+) (-) :     : (+) (-) :
>  : (+) (-) :     : (+) (-) :
>  : (+) (-) :     : (+) (-) :
>  : (+) (-) :     : (+) (-) :
>  : (+) (-) :     : (+) (-) :
>  : (+) (-) :     : (+) (-) :
>  : (+) (-) :     : (+) (-) :
>  : (+) (-) :     : (+) (-) :
>  : (+) (-) :     : (+) (-) :
>  '---------'     '---------'
>
>> and it would create a symmetric e-field pulse that
>> expands at the speed of light, like a wave, but it isn't
>> electromagnetic.
>
>Nonsense.  A changing electric field induces a magnetic field, and a
>changing magnetic field induces an electric field:
>
>  ? × B = ?? J + (1/c^2) ?E/?t,
>  ? × E = -?B/?t.

Do photons have the same gravitational effects as their mass
equivalents?

Are people stupid for asking questions?


John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics

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Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-12 14:55 +0100
  Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-12 14:58 +0100
  Re: energy and mass john larkin <jl@glen--canyon.com> - 2026-02-12 07:43 -0800
    Re: energy and mass ram@zedat.fu-berlin.de (Stefan Ram) - 2026-02-12 16:23 +0000
      Re: energy and mass john larkin <jl@glen--canyon.com> - 2026-02-12 08:44 -0800
        Re: energy and mass ram@zedat.fu-berlin.de (Stefan Ram) - 2026-02-12 17:15 +0000
          Re: energy and mass ram@zedat.fu-berlin.de (Stefan Ram) - 2026-02-13 13:45 +0000
        Re: energy and mass Bill Sloman <bill.sloman@ieee.org> - 2026-02-14 05:12 +1100
          Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-13 20:26 +0100
            Re: energy and mass Bill Sloman <bill.sloman@ieee.org> - 2026-02-14 15:56 +1100
              Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-14 14:17 +0100
            Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-14 13:56 +0100
              Re: energy and mass Ross Finlayson <ross.a.finlayson@gmail.com> - 2026-02-14 09:39 -0800
                Re: energy and mass Ross Finlayson <ross.a.finlayson@gmail.com> - 2026-02-14 09:40 -0800
      Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-12 22:08 +0100
        Re: energy and mass Ross Finlayson <ross.a.finlayson@gmail.com> - 2026-02-13 10:07 -0800
      Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-12 22:57 +0100
        Re: energy and mass Ross Finlayson <ross.a.finlayson@gmail.com> - 2026-02-13 10:11 -0800
      Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-13 00:33 +0100
    Re: energy and mass nospam@de-ster.demon.nl (J. J. Lodder) - 2026-02-12 19:39 +0100
      Re: energy and mass john larkin <jl@glen--canyon.com> - 2026-02-12 11:04 -0800
        Re: energy and mass ram@zedat.fu-berlin.de (Stefan Ram) - 2026-02-12 19:22 +0000
          Re: energy and mass ram@zedat.fu-berlin.de (Stefan Ram) - 2026-02-12 20:16 +0000
          Re: energy and mass DJ Delorie <dj@delorie.com> - 2026-02-12 15:50 -0500
            Re: energy and mass ram@zedat.fu-berlin.de (Stefan Ram) - 2026-02-12 21:29 +0000
              Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-13 01:12 +0100
                Re: energy and mass DJ Delorie <dj@delorie.com> - 2026-02-12 20:59 -0500
                Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-13 03:15 +0100
                Re: energy and mass nospam@de-ster.demon.nl (J. J. Lodder) - 2026-02-13 11:27 +0100
                Re: energy and mass DJ Delorie <dj@delorie.com> - 2026-02-13 10:09 -0500
                Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-13 17:39 +0100
                Re: energy and mass nospam@de-ster.demon.nl (J. J. Lodder) - 2026-02-13 23:40 +0100
                Re: energy and mass ram@zedat.fu-berlin.de (Stefan Ram) - 2026-02-13 10:29 +0000
                Re: energy and mass DJ Delorie <dj@delorie.com> - 2026-02-13 10:21 -0500
                Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-13 17:34 +0100
              Re: energy and mass ram@zedat.fu-berlin.de (Stefan Ram) - 2026-02-21 15:24 +0000
            Re: energy and mass nospam@de-ster.demon.nl (J. J. Lodder) - 2026-02-12 23:12 +0100
            Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-12 23:27 +0100
        Re: energy and mass The Starmaker <starmaker@ix.netcom.com> - 2026-02-12 11:28 -0800
        Re: energy and mass nospam@de-ster.demon.nl (J. J. Lodder) - 2026-02-12 22:29 +0100
        Re: energy and mass Bill Sloman <bill.sloman@ieee.org> - 2026-02-14 05:22 +1100
          Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-13 19:58 +0100
            Re: energy and mass Bill Sloman <bill.sloman@ieee.org> - 2026-02-14 07:13 +1100
              Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-14 00:44 +0100
                Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-14 03:52 +0100
                Re: energy and mass nospam@de-ster.demon.nl (J. J. Lodder) - 2026-02-14 21:59 +0100
      Re: energy and mass Ross Finlayson <ross.a.finlayson@gmail.com> - 2026-02-13 09:50 -0800
    Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-12 22:03 +0100
      Re: energy and mass nospam@de-ster.demon.nl (J. J. Lodder) - 2026-02-12 23:12 +0100
        Re: energy and mass Bill Sloman <bill.sloman@ieee.org> - 2026-02-14 05:34 +1100
          Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-13 20:35 +0100
            Re: energy and mass nospam@de-ster.demon.nl (J. J. Lodder) - 2026-02-14 22:57 +0100
          Re: energy and mass nospam@de-ster.demon.nl (J. J. Lodder) - 2026-02-14 21:59 +0100
            Re: energy and mass Bill Sloman <bill.sloman@ieee.org> - 2026-02-15 17:50 +1100
              Re: energy and mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-02-15 12:47 +0100
                Re: energy and mass Bill Sloman <bill.sloman@ieee.org> - 2026-02-15 23:51 +1100
                Re: energy and mass nospam@de-ster.demon.nl (J. J. Lodder) - 2026-02-15 21:48 +0100
                Re: energy and mass john larkin <jl@glen--canyon.com> - 2026-02-15 08:13 -0800
                Re: energy and mass nospam@de-ster.demon.nl (J. J. Lodder) - 2026-02-15 21:48 +0100
                Re: energy and mass john larkin <jl@glen--canyon.com> - 2026-02-15 13:11 -0800
                Re: energy and mass Seymour Dobrov <ouo@yosdm.ru> - 2026-02-15 19:49 +0000
      Re: energy and mass john larkin <jl@glen--canyon.com> - 2026-02-13 10:04 -0800
      Re: energy and mass Ross Finlayson <ross.a.finlayson@gmail.com> - 2026-02-13 10:05 -0800
    Re: energy and mass Bill Sloman <bill.sloman@ieee.org> - 2026-02-14 05:00 +1100
      Re: energy and mass Ross Finlayson <ross.a.finlayson@gmail.com> - 2026-02-13 10:19 -0800

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