Q-reeus

And even then best to consult a specialist astrophysicist who could guess well enough if the general environment would be clean enough for a magnetic field gravitationally induced deflection to be extracted. For instance the mass quadrupole moment of magnatar might well dominate as a first order correction to spherical mass approximation. And maybe geodetic effect too (just guessing here). It's the specialist's job to try and account for all such things but such headaches I happily leave to them.

But maximum magnetic field can be according to the Wiki article 'greater than 10^11 Tesla'. That bumps up the field energy density by more than two orders of magnitude. But only over a relatively short time frame given field decay is in theory fairly rapid.

You were quite right to question validity of that earlier quote-mined passage claiming a magnetic field has *no* effect on a light trajectory. In GR any source of stress-energy-momentum density is a source of gravitation. And a magnetic field is at least a source of energy density and stress (Maxwell stresses). So it for sure will contribute to bending of a light trajectory. At 'normal' terrestrially available magnetic energy densities, the effect is minuscule. What that quote-mined passage was evidently implying was there is no appreciable *electromagnetic* coupling between a magnetic field and EM radiation. Even there, at extremely high magnetic field energy densities, QED nonlinearities come into play and there is actually a non-zero coupling - 'vacuum birefringence' e.g. https://cds.cern.ch/record/357780/files/9806417.pdf

As follow-on from my last post here: https://www.scienceforums.net/topic/117068-vector-theory-of-gravity/?do=findComment&comment=1081814 The mentioned then still forthcoming reply by Svidzinsky & Hilborn has now been posted at arXiv.org: Comment on 'Tests of general relativity with GW170817' https://arxiv.org/abs/1812.02604

Saying everything and therefore saying nothing. And even that only ventured after a definitive clarification from me that should have been too plain to misconstrue. Vintage effort.

You still don't get it. My main point there is not about whether J. S. Farnes's hypothesized 'solution' to DE/DM problem(s) is speculative and unproven or not. Of course it's speculative and unproven. The real point is his foundational position re dynamical properties of 'negative mass' follow Hermann Bondi's 1957 formulation. And that formulation is fundamentally flawed. When corrected, there is absolutely no possibility of 'negative mass' whose inertial mass (regardless of passive/active gravitational mass sign) is also negative. Not just speculative/unproven/hypothetical - utterly impossible. Since no-one with basic physics knowledge has had the balls to constructively and critically comment, here at last I provide a link to that article obliquely mentioned in the now oft linked to post: https://www.semanticscholar.org/paper/Negative-Masses%2C-Even-If-Isolated%2C-Imply-Hence-a-TonniUniversit/aa73b5b07e669a1dad279bf96f22484ba581296f Click on 'View Paper' tab for freely downloadable pdf doc. It probably has very few citations to it. For those most impressed by such, as opposed to quality of content, feel free to dismiss out of hand. I go by quality of content.

My actual position is crystal clear. Again: https://www.scienceforums.net/topic/117292-quantum-fluctuation-origin-and-anti-gravity-voids-expansion-theory-of-the-universe/?do=findComment&comment=1084150 That you cannot understand it and further choose as usual to misrepresent, is as expected.

Asserts the 110% for mainstream everything bulldog. At least here at ScienceForums.net, you're on a somewhat tight leash and aren't free to liberally pepper your real feelings towards me with f words. Have a nice day.

That propensity for quote mining brings the recent fork here full circle in a way: The actual situation is far worse than Bonnor supposed. Deafening silence from anyone with physics knowledge, and 'interesting' penalizing, tells me all I need to know about the worth of further participation here at ScienceForums.net.

Again - no it hasn't. Completely skew of the mark. Still hopeful someone with physics knowledge will respond as repeatedly asked. Nothing difficult involved. I made no 'stuff up' except in your mind. A general opinion with nothing specifically aimed at me needed no response. Making an issue out of matters lending themselves to artfully distorting and taking out of context an opponents position is not my idea of useful forum discourse.

Your typically convoluted and skewed reply was addressed specifically to me. So how about correcting point 6 which reads: [6] The "pushing" you describe is really the gravitational attraction of matter towards more dense regions of matter and away from the less dense regions. Wrong. I never claimed any such thing, and in fact you offered faint praise for one in particular of my earlier posts refuting that notion. GET YOUR FACTS STRAIGHT! The rest of your post there is not worth a dignified response. Everyone knows your militant 110% support for mainstream everything. And how you love to aggressively hound anyone not at that same 110% unqualified adoration level. PS: Another late edit of yours and the all important you word has been excised. Whatever - I'm looking for a knowledgeable physics/maths based reply to a specific claim. Not bluster.

If it doesn't exist, then it is quite relevant to any argument by anyone with regards to any perceived properties of that doubtful quantity. "However the big difference, arguably the biggest difference, between anti-matter and negative matter is that negative matter doesn’t exist". I recall you as being a long time enthusiast for the Alcubierre Drive notion that iirc absolutely required 'exotic matter' aka 'negative mass' for it's hypothetical justification. Are you now saying negative mass for sure does not exist? That is, abandoning unconditionally all support for Alcubierre Drive and similar exotica? Dear StringJunky, hello. I note your title is Glorious Leader and rank is Genius. Given those nice attributes, may I assume that having ventured in here, you will now have no difficulty or reticence in offering a meaningful, specific response to my earlier post 'hinting' Bondi's position re 'negative mass' is unphysical? [Why the hell are my posts merged like this? Is there no easy fix?]

To deny there are entrenched positions in mainstream science is your prerogative. To gain a feel for the relevant subtle issues I suggest a read through e.g.: https://plato.stanford.edu/entries/scientific-objectivity/ It's clearly - and intentionally briefly - laid out back in my earlier post: https://www.scienceforums.net/topic/117292-quantum-fluctuation-anti-gravity-anti-matter-void-expansion/?do=findComment&comment=1084150 Well as stated earlier, I prefer feedback from folks here with actual physics/maths background. But if you want to give it a stab - try and keep it actually relevant to my argument. Your late edit addition above does not address my argument against Hermann Bondi's 'standard' negative mass basic propositions.

I cut & pasted largely from what was posted at another forum - which IS overwhelmingly a PC-centric platform despite it's pretending-to-be-otherwise forum name. So I forgot to excise the PC bit here. As for your comment re mainstream - well my earlier post here is meant to highlight imo one example where entrenched mainstream thinking has been plain wrong. If you have a specific physics/maths based response arguing otherwise - let's have it! PS - I won't post a link, but this back-and-forth between sub-forums episode reminds me of a golden oldie Tommy Roe song 'Dizzy'. There on YouTube btw.

Where to start..... I received NO email alert re responses to my last post that evidently was the trigger for this thread being moved from Speculations to A & C. The next posting linked to a redundant and inferior article to that which I had linked to. And made NO comment on my own poser. The next post which responded to mine basically butchered mine by placing a next to final passage to the front, and then failing to include my all-important quotes that left the rest quoted as almost meaningless. Seems no-one here with actual physics/maths training is prepared to risk a focused response to: 'What say you good PC/mainstream folks here - was he right or wrong?' As I wrote then, there is a newly discovered article backing my pov. But I expected a reasoned response from knowledgeable folks to just the intentionally brief argument already given. And btw, the original thread title during its Speculations sojourn: 'Quantum Fluctuation Origin and Anti-Gravity Voids Expansion Theory of the Univers' (yes an e was missing at the end - likely owing to title exceeding allowed length)

I'm a little hesitant to bring this thread back to life, but...quite recently in another forum, the following was posted: https://www.independent.co.uk/news/science/dark-matter-energy-solution-theory-negative-mass-astronomy-astrophysics-a8668476.html Then another posted this arXiv link: https://arxiv.org/abs/1712.07962 On p2, 2nd para in that arXiv article there is the following: 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: Wrong, and wrong. To (hopefully) see why, realize that an inductor is properly the magnetic inertia analog of mass. The well known 'natural response' of an RL circuit is: I(t) = I_0(exp(-Rt/L)) For standard derivation and definition of terms, see e.g. Appendix here: https://www.khanacademy.org/science/electrical-engineering/ee-circuit-analysis-topic/ee-natural-and-forced-response/a/ee-rl-natural-response Substituting -L i.e. negative inductance for positive inductance L there is perfectly legitimate mathematically. Physically, the result should be obvious. As also the implication for supposed negative inertial mass. I knew this result for quite some years, but only just now found an article backing it up explicitly. In a somewhat long-winded but imo rigorous manner. (No I won't post a link to it, just yet anyway.) Now Hermann Bondi was a 'giant' in the GR community with a very impressive track record. Moreover, his general conclusions re 'negative mass' have been scrutinized by many other famous names within the GR community, and in general adopted as 'physically sound'. What say you good PC/mainstream folks here - was he right or wrong? PS: The author J. S. Farnes of 1st and 2nd linked articles above does NOT claim his DE/DM is anti-matter! The basic dynamical implications there have imo relevance here.

I skimmed back through earlier posts just to check if there was a link to fairly recent large scale cosmic evolution simulations. Here's one hit: https://www.youtube.com/watch?v=32qqEzBG9OI Indicates just how good the match between theory prediction and observation has become. No input assuming anti-gravity anywhere. Another one that goes into technical details I cannot follow but you get the idea it's very complex with lots of factors involved: https://www.youtube.com/watch?v=wI12X2zczqI Again - the physics makes no use of anti-gravity to arrive at voids and webs structures actually observed. Recall too that growth is in part a consequence of an overall cosmic expansion - hence voids growing reflects that.

OK thanks that sufficiently clarifies.

Really? Then if my itemized list was such 'common knowledge', why only I made the responsible effort to actually post it all here? No need to answer btw. It's all too obvious - obviously.

coffeesippin - you may have noticed I'm the only one to point out a basic physics reason why it's hugely unlikely anti-matter anti-gravitates. There is more. To itemize: 1: Consistent observations of deflection in magnetic fields shows that at least for charged anti-matter, matter and anti-matter inertial mass are equal. Equivalence Principle then requires equivalence of gravitational mass. Only Wheeler-Feynman notion of anti-particles being ordinary particles traveling backwards in time logiocally suggests anti-particles anti-gravitate. But since that violates EP as per above, few these days give the idea any credence (1: here already covered in earlier post). 2: When particle-anti-particle annihilation occurs e.g. electron-positron -> gamma ray pair, one doesn't have a net zero gravitational mass outcome. Which outcome should be the logical expectation if indeed the input is positive gravitational mass electron + negative gravitational mass positron. (There is also a conundrum for standard physics hidden in positron-electron annihilation btw, but I won't expand on that here). Point is, anti-gravitation of anti-particle idea fundamentally conflicts with the expectation of conserved net gravitational mass. 3: According to the vixra article you cited earlier: http://vixra.org/pdf/1001.0007v2.pdf , anti-particle anti-gravitation has a very strange character. Anti-particles repel both ordinary particles AND other anti-particles. Which is equivalent to claiming negatively charged particles repel each other and attract positively charged particles (what actually occurs), but positively charged particles attract negatively charged AND other positively charged particles (which does NOT occur). Hence there is imo no logical consistency to what that author posits. It leads to bizarre runaway scenarios. 4: The standard picture requires BSM physics to cope with the observed ~ 1 to 10^10 ratio between matter particle and photon numbers. Which outcome implies a slight asymmetry between particle and anti-particle annihilation in the very early universe. As posited by voids = anti-matter regions scenario, there is actually a perfect net balance between matter and anti-matter in current universe. But there simply was no chance for gravity to appreciably separate matter from anti-matter in the early hot BB. Either total annihilation to radiation occurred if there was no BSM annihilation asymmetry, or you have the standard picture of an entirely matter over anti-matter dominated matter content. It's ok to hypothesize a radically new model, but also important to dispassionately check for consistency with known physical principles and their implications.

coffeesippin - there is a very good argument why anti-matter should have the same gravitational sign as ordinary matter. In every anti-matter particle detection so far observed, stretching back many decades, it's always the case deflection in a magnetic field is exactly opposite to the corresponding ordinary matter particle. This immediately means the inertial mass of both particle and anti-particle must be identical in magnitude and sign. The Equivalence Principle then requires the gravitational masses to likewise be identical. So if anti-gravity anti-particles were true, that fundamentally violates the Equivalence Principle. It's why afaik a main reason the Wheeler-Feynman notion of anti-particles being ordinary particles traveling back in time, was abandoned. Because that idea does naturally imply anti-gravitation of anti-particles. ????? Just read the two paras under 'The evidence spoke for itself' in that very article you linked to!! First observed in 1932 (positrons), and whole anti-hydrogen atoms made back in 1995. Now if you meant antimatter in an astronomical/cosmological setting, that should have been clearly stated. And you would still have been wrong: https://arxiv.org/abs/1009.4620 What hasn't been identified is large scale structures i.e. voids comprised mostly or entirely of anti-matter as neutral atoms/molecules. [Just saw your late edit at bottom admitting positrons have been created in lab. Also anti-hydrogen - as mentioned in the very article you cited.]

https://www.scienceforums.net/topic/117068-vector-theory-of-gravity/?do=findComment&comment=1081799 You evidently have a conveniently short memory - or just straight-out sheer 'GR = Truth' prejudice. No. There is no objective justification for booting this forked thread to Speculations. That many GR buffs and even famous authority figures, and also higher-ups here, cannot properly handle the straightforward and entirely unambiguous meaning of R_μν = 0 (in vacuo), is no reason to characterize my pointing out it's rigorously logical consequences as 'speculation'. But I well understand why forum 'realpolitik' has processed it here differently. There are conflicting positions on 'gravity does/does not gravitate' among GR authorities. Unfortunate fact. As you see it - as one having zero technical expertise to pass objective judgement.

I could quote you from elsewhere as having stated on numerous occasions that GR is 'as perfect a theory as could ever be' (exact words may vary but that was your position). Since then you have picked up on articles toning that down somewhat - like your bold text quote above. What exactly you are inferring re my position baffles me. Nothing there to really comment on. It's a safe statement re 'GR is not the last word' - but the hidden subtext to that is 'which will only be modified via a quantum gravity 'final theory'. As for the 't Hooft article - stop being lazy. Reproduce here any passage(s) specifically bearing on whatever your unstated, notionally relevant point actually is.

Only to further demonstrate your confused thinking and erroneous claims. I could hope you would lay off continued serial posting here. But knowing you that is sadly unlikely.

When mining with the evident hope of finding a 'dagger' article(s) to 'kill' my arguments here, it pays to actually understand what said article(s) really covers. Important clue in your own reproduced Abstract re ScienceMag article (non-paywall version: https://arxiv.org/abs/1806.08300): WEAK FIELD. Immediately, the finding cannot be a threat to either of the two rival to GR theories mentioned earlier this thread. Both of which are known to reproduce all the weak-field 'confirmations' of GR. So what 'other theories' have been ruled out here? Well the Forbes article makes it pretty clear - MOND type theories meant to do away with dark matter. The authors, as typically done, forget to mention that leaves quite a few rival theories to GR intact, which all likewise pass this galactic lensing study findings. Sorry - your dagger appears to be pointing inwards. Since you failed to pick up on the weak field implications. Had you done so, it would have been pointless posting the links and cut and paste selections. Back to mining the internet for more ammo.