geordief

Is that just a mathematical convention?Could it just as well be the other way round ? (positive energy could be considered negative and vice versa) Or does it have to be that way?

Is the the energy that is bound up in matter (= its mass?) bound up in the form of the various bonds between its constituent parts? If so ,is that a bit like Cheshire cat territory where all that was left of the cat was its grin? I think Lewis Caroll was also a foremost mathematician of his day before falling out of favour for some reason I don't recall.

Yes I think it is accepted that ,as the universe expands galaxies ,one by one will recede from our point of observation at greater and greater speeds If we look closely enough and long enough I assume that we will ,at least in theory catch one of these galaxies in the process of actually disappearing from view (when its speed of recession exceeds the speed of light) At that point we will conclude that that particular galaxy we no longer see is still there , but no longer as a part of the observable universe Now it would be a part of the "unobservable universe "-and so "beyond the observable universe" We cannot see anything beyond the observable universe but can deduce its existence in an empirical way Does that clarify what I was saying? (Hope I didn't sound like Mystic Meg in that previous post😀

What might be the overall energy of the observable universe? Is it possible that ,to an approximation it might add up to zero? Since there is a universe beyond what we can observe that may mean we can never know the answer but are there any models that could be used to answer the question? (Are there as many possible answers to the question as there are frames of reference?)

Nowhere ,but it is on the back foot and under attack. First priority is to keep the democratic gains it has acquired over the years.

I meant defending from within.

Authoritarian regimes will just remain fans (if with the usual competing interests) Democracies seem to have enough on the plates just defending their own political systems. What would be good would be if the Chinese people saw the monkey on their back.

Do we have any empirical evidence as to which of the different forms of democracy are most effective in truly representing the population -and which do so without pandering to their "worse"(eye of the beholder and all that) qualities. For example ,voting is obligatory in some countries Does that seem to make a positive difference?(not sure I am enamoured of the Australian political system-or the policies that have been pursued of late)

I am still wondering how one calculates the new waveform 'or rather what is the relationship between the "ingoing" waveform and the"post interaction" waveform? Is it again a probabilistic relationship? Is there any relationship as such?

Should our politicians concern be to just get reelected? After all they will only get to be reelected if enough voters approve of what they have done in office. Is it not good enough for them to just fulfil that commitment,(to be sufficiently popular)? Do they have to be "better" than the people who voted them in or it it their highest duty to represent them warts and all?(men of the people or the vanguard of the people?)

What happens when the waveform "collapses"? Is a new waveform created? What ,then is the relationship of the new waveform to the old? There is no throwing of the dice in this process ,is there?

Have noticed fewer moths this year in the garden or inside the house.Even the cabbage whites I have hardly seen. Hundreds upon thousands of flying ants and a bare minimum of ladybirds No shortage of dragon flies ,young ones around this time-or young frogs in the weeds. (We got none of that heatwave around here ,if that would account for anything)

Where did you see it ?(it looks a bit worse for wear now😉

So it seems possible (ie not ruled out) that the acceleration could come to a halt and become negative ,leading to a big Crunch -even though, as I understood it at the time the big Crunch idea fell out of favour when the accelerating expansion was first observed. Is that fair?

How did they measure that the actual acceleration was accelerating? It sounds very hard to me.

I have learned that the rate at which the galaxies are receding from each other is accelerating. (Quite the surprise when this was discovered ,I seem to recall) So we have an ongoing acceleration of the recessionary process. Is there any way to quantify this acceleration and so determine whether this acceleration itself is constant or whether it could be slowing down ?(or even speeding up) I think the mathematical term is "jerk" Could the jerk be negative and how could we know?

So ,in practice one would just revert to the Newtonian model? There is just too much gravitational self interaction for the process to be fruitful? Does that change at all if the system reduces to fewer and fewer sources of mass and energy-momentum? Might the gravitational wave simulation that so successfully predicted the wave pattern when those two black holes collided have been done the way you suggested?(they didn't fall back on Newtonian mechanics for that ,surely did they?) I realize that modeling gravitational waves is not the same thing as adding spacetime curvatures.

Some gardening can be dishonest-there is hope for us all

They should have given him a proper job like a gardener when they caught him hiding in the shrubbery. https://gizmodo.com/correction-sean-spicer-wasnt-hiding-in-the-bushes-he-1795117363

Do the multiple sources all have to be calculated individually ? How does the boundary allow one to get to the curvature of the point in space we are interested in? Is there a spacetime distance between that point and the boundary? Do directions come into play ?(is/are there a spatial or tempero-spatial relationship between the sources and the point of which we wish to calculate the curvature?)

I understand that spacetime curvature is mathematically modelled as a local effect. But the effect of gravity is felt at great distances Is it necessary for all the local spacetime curvatures to be summed geometrically for this large gravitational field to be modelled? If so,is there some technique for doing this ? Suppose we are looking at the curvatures produced by the moon and the earth and we pick a point midway between the line that joins their respective centres,how would one calculate the curvature due to the earth and the curvature due to the moon at that point? And how do we add them?

So am I now.I still can't see it :-(

Can't see it either (I see the "achievements" section but it just lists my rank and my rep there) Does that facility only work on a desktop,maybe?

Well if Trump was in custody I might well be tempted to dig a moat around the place and fill it with stingrays and prepared sinkholes -rather than contribute to a GoFundMe account to raise his bail (which would be promoting violence,no?)

I hid in my own garden in the dark after knocking for fun at a neighbour's door. "I know you are there" he called out. We also used to throw stones on the roof of the neighbouring chapel when they sang their piece. We were the hard boys.