Is negative energy possible ?

Discussion in 'Physics & Math' started by Mark Turner, Jul 11, 2019.

  1. Mark Turner Registered Member

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    y-y=+v ?
     
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  3. exchemist Valued Senior Member

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    No, y-y = 0, obviously, though what this has to do with your question is not clear.

    Energy is a property of a physical system and is really a form of book-keeping. As such it can be negative, relative to a datum level chosen in a particular way. For instance, gravitational potential of a pair of masses is customarily measured relative to a datum zero energy at infinite separation. So their GPE, as they move closer together from infinite separation, becomes increasingly -ve.

    Similarly the energies of chemical compounds are generally described as negative values, relative to the energy of the elements of which they are composed.

    In both cases, this convention reflects the fact that the combined objects have less energy than the separate ones and that, conversely, it takes an input of energy to separate them.
     
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  5. Mark Turner Registered Member

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    Thank you for your reply .

    My question and math is related to spacetime curvature and -y creating +ve .

    If we could curve a hypothetical Higgs field towards us , according to Newton , every action has an equal and opposite reaction .Wouldn't the hypothetical Higgs field , pull back creating +ve of the force source ?

    Wouldn't that be considered a negative energy ?

    Thanks in advance .
     
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  7. DaveC426913 Valued Senior Member

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    Sorry, this is word salad.
     
  8. exchemist Valued Senior Member

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    I agree with Dave. If you care to raise a point that has some meaning in physical science, I'll try to respond.
     
  9. Seattle Valued Senior Member

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    No matter how often it happens on here, I'm always amazed. How does one start from a point of not understanding a subject and then go to assuming that you know enough to start making up the rules as you go along?

    Is it a troll or just a special kind of personality? Surprise, we just don't know...

    y-y=ve
     
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  10. DaveC426913 Valued Senior Member

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    As long as they're asking questions - as opposed to asserting - I'm OK.

    I'm going with the benefit of the doubt. MT is learning, and trying to apply what he's learned, then asking if his extrapolation makes sense.

    That's kind of what you're taught to do in school. When you come across a problem that's not exactly like the one that was on the board - you try to take the specific example, and generalize the lesson to other applications.
     
  11. exchemist Valued Senior Member

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    Absolutely. Trolls are plentiful enough that on occasions like this I find myself asking the question: "Is this serious or a wind-up?" But usually wind-ups have a giveaway annoying quality about them, which this does not have. Let's see if this person can come down to earth a bit and ask something with a meaning to it.

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  12. Seattle Valued Senior Member

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    Thanks in advance.

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  13. exchemist Valued Senior Member

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    Yeah yeah, I know, I've booked myself in for an "I told you so".

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  14. Q-reeus Valued Senior Member

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  15. exchemist Valued Senior Member

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  16. Q-reeus Valued Senior Member

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    You've got me re double amber vs single amber, but - amber is imo the right color for sure. Anyway, not to be in this thread just to be 'mean spirited', here's a hopefully positive input:

    Below is reproduced with slight editing, a post that was for whatever reason, blocked even though claiming to have been posted, on Sabine Hossenfelder's BackReaction blog in
    https://backreaction.blogspot.com/2018/12/no-negative-masses-have-not.html

    On p2, 2nd para in that Farnes authored arXiv article https://arxiv.org/abs/1712.07962 there is the following:

    "...However, throughout this paper I specifically only consider a negative mass that is consistent with general relativity, so that the weak equivalence principle always holds and negative mass matter always has identical inertial and gravitational mass..."

    That single statement imo dooms the author's hypothesized DE/DM 'solution'. His accompanying scenarios in Fig.1 is (imo!) only correct wrt uppermost one. The other two follow Hermann Bondi's fundamentally wrong 1957 formulation of 'negative mass basic dynamical characteristics'. Thereafter adopted as mainstream position - with various dissenters however. In the 3rd para p2, it reads in part:

    "...However, if a force is exerted on a negative mass, the mass will move towards the applied force. Nevertheless, a negative mass at the surface of the Earth would fall downwards in a similar manner to a positive mass..."

    Wrong and wrong. Here's imo why. The well known 'natural' response of an RL circuit is a decaying exponential current I(t) = Io(exp(-Rt/L)), where Io is the initial current flowing at time t = 0, R the circuit resistance, and L the positive valued circuit inductance. Substitute a negative inductance -L, which is perfectly valid mathematically, and of course one then has an exponentially rising current - a runaway situation.
    The valid analog is that of a fluid flowing in a resistive closed-loop tube. With positive fluid inertial mass density, the flow velocity again exponentially decays with time, but if negative, one has bizarre runaway exponential growth.
    For standard derivation and definition of terms, see e.g. Appendix here:
    https://www.khanacademy.org/science...-and-forced-response/a/ee-rl-natural-response

    This fairly obviously translates more or less directly over to the case of a supposed negative inertial mass particle or field. Negative inertial mass particles, given the slightest initial nudge, would self-accelerate towards infinite negative KE. Likewise negative inertial mass density fields are unstable against perturbative oscillations self-amplifying to impossible levels.
    [With likely the exception of initial cosmic inflation phase, where indeed exponential self-acceleration results. Probably most formulations invoke negative pressure but positive energy instead.]
    Such was obvious to me for quite some years back, but only a short while ago found an article explicitly backing that up, howbeit in a more long-winded but rigorous manner:
    https://www.semanticscholar.org/paper/Negative-Masses,-Even-If-Isolated,-Imply-Hence-a-TonniUniversit/aa73b5b07e669a1dad279bf96f22484ba581296f
    "Negative Masses, Even If Isolated, Imply Self-Acceleration, Hence a Catastrophic World."

    See esp. p5. I endorse entirely the main claim. Regardless of the notional sign for passive/active gravitational mass (or mass density), negative inertial mass (or mass density) is totally unphysical. I would take it one further - apart from the gross runaway motion, how could a negative inertial mass particle even stably exist in the first place? Similarly, anyone think a stable atom with negative inertial mass electrons could make sense?

    Both Farnes and Bondi whose hypothesized negative mass properties Farnes has adopted, imo got it wrong at a basic conceptual level.
     
    Last edited: Jul 12, 2019 at 2:32 PM
  17. DaveC426913 Valued Senior Member

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    In my view, the consequences of assuming trolling greatly outweigh assuming sincerity.

    I assume sincerity, and I am right: I teach a potential science fan some new stuff. (This is why I'm here.)
    I assume sincerity, but I am wrong: My ego is tested because someone catfished me.
    I assume trolling, and I am right: I pat myself on the back for being clever.
    I assume trolling, but I am wrong: I likely have put a potential science fan off.

    If someone asks some science questions - and I answer them in good faith - and they later turn out to be a troll, what exactly have I lost? My ego is not so fragile that I have to be wary of being tricked. Trolling is not a contest of smarts - no matter how much a troll might like to think so - that's just handing power to them to try to outsmart you.

    Once I ran through all those possibilities, it leads to a very simple set of rules:
    - provide answers to questions in good faith
    - stop engaging if trolling sets in*
     
  18. DaveC426913 Valued Senior Member

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    *unless it's river. He's too harmless for normal trolling rules to apply. Like a kitten that thinks it's a tiger, river is just too entertaining.
     
  19. Michael 345 New year. PRESENT is 69 years old Valued Senior Member

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    Used to think same, along with Jan until both became to tedious

    Iggy to the rescue

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  20. exchemist Valued Senior Member

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    Yes that is generally my approach too and for the same reasons: benefit of the doubt, at least initially. The point at which the troll detector goes off is different for different people, however. Let's see if this person comes back. If it is Theorist again, I suspect this discussion will put him off.

    Correction: This is Theorist. Look at this post 7: http://www.sciforums.com/threads/what-is-the-difference-between-sr-and-gr.162093/

    "Could of", "must of", "I'd of thought", is a classic Theorist grammatical error. Also the "thanks in advance" is reminiscent of the "kind sir" stuff we had from Dylan a.k. a Theorist: http://www.sciforums.com/threads/is...ion-caused-by-heat.160007/page-7#post-3480113

    Plus of course the classic mathematical nonsense, 2-2= 3 stuff.

    So Q-reeus was right all along. I'd better let James know.
     
    Last edited: Jul 12, 2019 at 7:33 PM
  21. Q-reeus Valued Senior Member

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    Good catches! I merely went on the bizarre nature of OP queries. We have a forensics expert here.
     
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  22. James R Just this guy, you know? Staff Member

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    It's suggestive of a sock puppetry, but not quite enough to confirm at this point. Apart from that, IP records are not a definite match, although once again there are potential indicators. On balance, there's just not enough here to justify moderator action right now.
     
  23. DaveC426913 Valued Senior Member

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    Well let's get the bottom of this then!

    Hey Mark Turner, are you banned member Theorist?
     

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