Recent content by MikeL#

Thanks phinds for clearing that up - so I can tell the friend who asks me: 1. Real anti-matter (like positrons) definitely has positive mass/energy and not negative. 2. Black holes do not suggest anti-matter has negative mass - that would be misinterpreting QFT etc.

'the biggest misconceptions about black holes' Evapourating black holes suggest anti-matter has negative matter but is this really true? 1. I think anti-matter has positive mass - because when a positron and electron annihilate they emit 0.5MeV + 0.5MeV photons (exploited by PET-CT scanners)...

Black holes suggest anti-matter has negative matter but is this true? I think anti-matter has positive mass - e.g. a positron and electron annihilate giving off 0.5MeV + 0.5MeV photons where these photons have a huge positive energy. If the positron had negative mass then there would be no...

Thanks JorisL for your response and help. 0. I suspect you are unhappy about me writing ## g_{55} ## = 1 rather than ## \phi^2. ## This is to simplify (save space). Think of a charged star rather than nucleus. Only I am setting charge and field to zero (so ## g_{55} ## = constant is valid) - to...

Question outline: In the case of 5d Kaluza (Klein) GR with NO charge and NO gauge field we expect 5d to reduce to 4d GR exactly. So this should be a very simple useful sanity check.s the side and corner terms of Einstein, Ricci and Energy tensors are zero, then R would be the same in 4d or 5d...

Update. R(5) to R(4) + EM help needed 1. On more carefully working through original Kaluza ideas, I am having a problem with the standard reduction of the 5d GR Lagrangian expression into 4d GR + EM. I am using B_\beta = \kappa A_\beta and for now putting aside the non-standard idea (of...

Jostpurr, I wonder if you have being using these equations to grapple with the physics of our moving through time? Definitions: \tau = proper time \tau_c = proper time at centre of a mass distribution m = 1/ \tau_0 = mass Propositions: A: u(t,x) e^{ims} = v(s,t,x) is a more general idea...

Reason why \kappa so small when using Lagrangian with GR curvature. This post is a progress report where I attempt to sketch an answer to my original question (somewhat rephrased). I confess it was not so simple (as it assumes a basic intro to EM, QM, Lagrangian, curvature & GR). Then I sketch...

ict & signature 0. I think there was an excuse for using i=sqrt(-1) between 1905 & 1915. It helped to show a ‘rotational’ symmetry between x & ict, it saved using a metric, and only a few mathematicians/physicists would understand the subject anyway. 1. But it introduced unnecessary...

charge & mass 1. Country boy, thanks for your physics comments about allowing any charge, mass & x^5 (pre-QM). This encourages me to persist in clarifying what I have been referring to as the metric from Albrecht. 2. The comment that Klein’s idea was to quantize charge etc. (post-QM) gently...

Problems with the balloon thickness & radius. Jo - I like the snap-shot of your brain ticking over - I hope the following helps. 1. You are right about the 2d-balloon 2-sphere 2-surface - it is just an analogy for 3d space (or 3-sphere) volume (3-surface). Only the surface counts in this...

tips & references I would like to add some more tips I have learned for new PF users, summarise PF references to the question, comment on nomenclature & finally make some comments about Appendix 2. The first post here is a summary of the question. Later posts re-express the summaries and...

Joe, Not a dumb question, but let’s split it into 3 parts. Part 1 - ignoring expansion of universe, time dilation and quantum mechanics: Is time a dimension in the sense that we can travel through it, just as we can travel through space? 1. Yes (but see 6. below). 2. We are all time...

I have also wondered about this. I think the 'Introduction to loop quantum gravity' will help. Try dipping into the last page of the first post.The following is speculative: My explanation is that when the Kaluza metric is used with the GR Lagrangian you get the Plank Mass. Klein then went on...

experiment to see if can update here Note the expression for d_\tau(u^5) above is entirely consistent with d_\tau (1 - \kappa A_j u^j) !