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Negative mass (was: More Physics Heresay)

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Thomas 'PointedEars' Lahn wrote:

> Michael J.  Strickland wrote:
>> Would [negative mass] repel positive mass and attract other negative 
>> masses?
> 
> AIUI, yes.

Apparently my understanding was not correct:

,-<https://en.wikipedia.org/wiki/Negative_mass>
| 
| […]
| Runaway motion
| 
| Although no particles are known to have negative mass, physicists 
| (primarily Hermann Bondi in 1957,[3] William B. Bonnor in 1989,[9] then 
| Robert L. Forward[10]) have been able to describe some of the anticipated 
| properties such particles may have. Assuming that all three concepts of 
| mass are equivalent the gravitational interactions between masses of 
| arbitrary sign can be explored, based on the Einstein field equations:
| 
| · Positive mass attracts both other positive masses and negative masses.
| · Negative mass repels both other negative masses and positive masses.
| 
| For two positive masses, nothing changes and there is a gravitational pull 
| on each other causing an attraction. Two negative masses would repel 
| because of their negative inertial masses. For different signs however, 
| there is a push that repels the positive mass from the negative mass, and 
| a pull that attracts the negative mass towards the positive one at the 
| same time.
| 
| Hence Bondi pointed out that two objects of equal and opposite mass would 
| produce a constant acceleration of the system towards the positive-mass 
| object,[3] an effect called "runaway motion" by Bonnor who disregarded its 
| physical existence, stating:
| 
| “	I regard the runaway (or self-accelerating) motion […] so 
| preposterous that I prefer to rule it out by supposing that inertial mass 
| is all positive or all negative.	”
|   — William B. Bonnor, in Negative mass in general relativity.[9]
| 
| Such a couple of objects would accelerate without limit (except 
| relativistic one); however, the total mass, momentum and energy of the 
| system would remain 0.
| 
| This behavior is completely inconsistent with a common-sense approach and 
| the expected behaviour of 'normal' matter; but is completely 
| mathematically consistent and introduces no violation of conservation of 
| momentum or energy. […]
  
>> If we could find or produce anti-mass, would we observe anti-gravity?
> 
> Yes, see above.

I am not so sure about that anymore.
  
-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.

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More Physics Heresay Michael J. Strickland <michael06582@comcast.net> - 2016-07-21 03:05 -0400
  Re: More Physics Heresay Alan Folmsbee <omnilobe@gmail.com> - 2016-07-21 02:15 -0700
  Re: More Physics Heresay Sergio <invalid@invalid.com> - 2016-07-21 10:22 -0500
  Re: More Physics Heresay Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-07-24 18:18 +0200
    e.e hearsay, here said ... that sylli poet? noTthaTguY <abu.kuanysh05@gmail.com> - 2016-07-25 19:59 -0700
      Re: e.e hearsay, here said ... that sylli poet? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-07-26 07:39 +0200
    Re: More Physics Heresay "Y.Porat" <y.y.porat@gmail.com> - 2016-07-26 01:08 -0700
      Proton mass (was: More Physics Heresay) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-07-26 15:35 +0200
        Re: Proton mass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-07-26 17:05 +0200
          Re: Proton mass john <johnsefton288@gmail.com> - 2016-07-26 08:09 -0700
    Negative mass (was: More Physics Heresay) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-07-31 09:05 +0200
  Re: More Physics Heresay Sylvia Else <sylvia@not.at.this.address> - 2016-07-26 13:03 +1000
  Re: More Physics Heresay Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2016-07-26 12:43 -0400
    Re: More Physics Heresay Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-07-26 20:31 +0200
      Re: More Physics Heresay noTthaTguY <abu.kuanysh05@gmail.com> - 2016-07-26 11:57 -0700
    Re: More Physics Heresay Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-07-31 09:07 +0200
      Re: More Physics Heresay ben6993 <ben6993@hotmail.com> - 2016-08-01 00:19 -0700
  Re: More Physics Heresay ben6993 <ben6993@hotmail.com> - 2016-07-26 15:10 -0700
    more sloganeers noTthaTguY <abu.kuanysh05@gmail.com> - 2016-07-27 12:19 -0700
      Re: more sloganeers noTthaTguY <abu.kuanysh05@gmail.com> - 2016-07-28 14:26 -0700

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