MigL

Just did a quick read of this topic. A lot of claims made; very little actual proof, and no evidence. What I took away from"prime Mechanics' is that gravity gravitates. Anywhere you have gravity you have an energy density due to that gravity, which produces large amounts of virtual particles. These virtual particles then make their own contribution to the gravitational field, and account for such things as Dark Matter ( although I don't see how it accounts for Dark Energy as that is dominant in low gravity areas ). I suppose that line of thinking could also be applied to the Big Bang, and the generation of enough gravitational energy to spawn a universe. Now, virtual paricles are scale dependent; very few at large interaction separations, but their numbers increase dramatically as interaction separation decreases. Still, for typical distances, like interactions in a galaxy, it should be possible to get a 'ballpark' number of virtual particles, the energy density they would provide, and the net effect this would have on galactic rotation, if any. Do you have such numbers ? Does your book ? Or is it merely handwaving without evidence ? ( I don't know about the 60s, but early 80s Physics required us to have evidence for any assertions we made ) Edit B the way, what exactly is a 'laminar flow' processor ? There is little or no turbulence in electron, or hole, motion in a semiconductor.

Haven't watched the full lecture yet, Genady; maybe when I have a little more time. But I definitely liked his explanation of negative pressure. A lot more elegant than the mess I posted in the 'Testing Creation' thread. ( I'll have to remember gas-filled pistons and forget about springs )

Maybe it's too subtle for me to grasp, but I fail to see a difference. All other interactions are fields acting on a fixed background stage. Gravity, as mdelled by GR ( and LQG ) goes a step further, and the formerly fixed background stage, space-time ( more specifically, its geometry ) becomes an active participant in the interaction and can be modified by it. The difference is not that large, and maybe it is renormalization ( which I find somewhat ad-hoc ) that needs to be scrapped, and a new, more robust method, devised to handle the divergences. You could be right, and it may be just wishful thinking on my part, but I like the idea of all interactions descending from an original 'superforce' at the beginning. It would make things a lot neater.

I believe some people believe in God, because they have a 'need'. I , myself, have no need for a Dog, because I have dyslexia.

Maybe I should have just left it as "all particles were massless during the radiation era", and avoided the confusion. Two other problems 'solved' by inflation, the horizon and the flatness problems. PBS SpaceTime does a better job of explaining these issues than I could. With graphics even.

Yet we find that at Planck scale energies, all interactions, including gravity, are pretty well equal. This would seem to indicate that a Grand Unified 'Force' may have been present doring the Planck epoch, and gravity dissociated from it shortly thereafter when energies dropped. I have also always considered renormalization a mathematical 'trick', and maybe we simply haven't found the right rick to handle the infinities of quantum gravity field theory. But whatever method is finally devised ( I like LQG also ), any quantized field theory, even if the quantized field is geometric, will have a mediator particle. So don't throw the graviton out yet.

Correct. Before Elecroweak dissociation, electrons/neutrinos/quarks and W/Z bosons hadn't aquired mass yet; everything moved at c .

Many cases of people mistakenly pronounced dead while still alive; some buried even. Absolutely NO cases of actually dead people coming back to life.

IIRC, A Guth's initial inflation model came in the 80s, right after Electroweak unification, and originally used theHiggs mechanism due to symmetry break, and drop from false zero point energy to account for inflation. I still have his book, somewhere. The problems without inflation are much greater than those introduced by inflation. How do you account for isotropy and homogeneity unless, at some point, the universe was small enough for information to travel across it and establish an equilibrium , ie causal contact ? That is impossible if the universe expanded linearly from a smaller size; only an exponential size increase makes sense. The Planck era is at 10-43; before that period quantum foam without geometry would have prevailed, and that is considered to be the start of the Big Bang. According to A Guth's initial conjecture ,inflation would have been caused by Electroweak dissociation, and the energies involved would put this at about 10-35 to 10-32 sec .

Causality necessitates the transfer of information. A moving shadow, or dot of light, does not transfer any information. The maximum speed of information transfer is c .

You uys seem to be talking past each other. A geometric field theory of gravity does not require a mediator particle, as Mordred states; it is 'sufficient' on its own. Yet we know that it isn't exactly 'sufficient' at small separations/hi energies, and a quantum field theory of gravity is required to cover those areas of applicability. We also know that a quantum field theory of gravity does require a spin2, massless mediator particle which we have termed the graviton, as MisterMack states. It could be quite a while before quantum gravitytheory and gravitons are an established fact, though.

Didn't notice this when you first posted a couple of years back, but that 1038 times is actually 1038, or 38 orders of magnitude weaker. Same goes for the other numbers posted. Keep in mind that this is at atomic particle scale; if you compare at scales approximately 10 times the mass of our sun, you will find that gravity is the strongest and no other interactions can resist gravitational collapse to a Black Hole As Studiot mentions in the first answer, scale matters. A lot of the differences between Newtonian gravity and GR are due to temporal curvature. The anomalous orbit of Mercury, in the strong gravity field of the Sun, is mostly due to temporal curvature..

It is very difficult to think of an analogy for negative gravitational pressure. Think of it as a coiled spring. Gravity, in GR, acts on all forms of energy, and if gravity were to compress this spring slightly, its gravity would further increase because of the added energy of compression. This would be an example of positive gravitational pressure, and gravity acts like we expect it to. Now, for the negative pressure example, the best I can come up with is a stretched spring, under tension, but it's not gravity that's pulling it apart ( no such thing as repulsive gravity ) rather, it is the universe itself through the gravity field, or Cosmological Constant, aka Dark Energy, that is doing the stretching. This CC or Dark Energy is a scalar term that does not vary with distance, whereas the rest of the gravitational terms do, and so we have gravity dominating at close distances. But when gravity decreases with the square of the distance, it is a given that at a certain distance the gravitational terms will be less than the CC or Dark Energy term, resulting in expansion. Sorry if I could not be clearer.

Interesting read, Mordred. I especially enjoyed the speculative sections near the end.

I'm very particular about social contact also. I would prefer if fat smelly old men kept their distance. However, Covid or not, good looking women can hug me whenever they want ...

On the other hand, my front wheel bearing is getting noisy. Any 'theories' on the easiest way to knock out the bearing ? But seriously, the only part of your post I'll agree with is that 'prior to the Big Bang and inflation,the universe may have existed in a razor's edge equilibrium for a very long time, depending, of course, on how one measures time in a universe where there is no time yet. The Big Bang was the disruption of that equilibrium.

If I may ... It makes no sense to talk about energies needed to create a universe at the beginning of time. Noether's theorem states that 'every differentiable symmetry of the action of a physical system with conservative forces has a corresponding conservation law'. If a process exhibits the same outcomes regardless of time. then its Lagrangian is symmetric under continuous translations in time, and as per Noether's theorem, this symmetry accounts for thelaw of energy conservation of this system. ( paraphrased from Wiki ) As the beginning of time is decidedly non-symmetric, the energy conservation law is not constrained to hold, and the quantum fluctuation would not be constrained in the amount of energy it could introduce to the system. Maybe enough to create a universe.

Notice that I did not call you any of those; what I said was 'hare-brained ideas' . IOW, a criticism of your idea, not you personally. Judging by your answer, however, one could be led to believe that you may have been accused of those qualities previously.

That's gotta be a lifetime's worth of nail clippings. Some people collect the most odd things. And I do use a SS stovetop espresso maker , but I have a few small 1-2 cup traditional aluminum ones. Those are the ones I remember from my youth in the 60s and 70s, Eise; like the Motta model in your photo. The link between Alzheimer's and Aluminum has never been factually estabilished, and while the prevalence of Aluminum cooking utensils has decreased dramatically over the last 40 years, the incidence of Alzheimer's has increased considerably during that time ( expected to almost double in 20 years ).

Yeah ... Right. ( why do all these hare-brained ides involve pyramids and vortices ? )

100 espresso pods at CostCo for Can$ 30, comes to 30 cents per espresso. ( as compared to Can$ 2.50 at the coffee shop down the street, never mind Starbucks ) But it's more about time and effort saving. Isn't that what money is for ? Personally I prefer the stove-top percolating aluminum espresso makers. When I was younger my dad would make espresso on Saturday mornings because he didn't have to work. The aroma would spread through the house and wake me when it started percolating. Every once in a while, when tme allows, I'll make it that way, just to re-live those memories.

You just kicked the can down the road. What is 'fair', to whom, and who gets to decide ?

Nespresso. Drop in a pod. Push the button. Enjoy your espresso.

People keep kicking them. They handle one more than the other. Looks like you had a vasectomy; one still has visible stitches ...

Not without defining 'moral' first. ( do you consider 'moral' an axiom, or self apparent truth ? ) We should all be talking about the same thing, should we not ?