We have considered nothing and I hope that thread took a few minds away from the weather.
I know so little about the concept of space time I spend a lot of time trying to work out what it says .... it seems to be geometry to me however so many speak about it as if it is a mystery and dont buy into some of the propositions used to expalin it... I think I understand it a little but have a problem with some examples I see in mags and sites that seek to explain it to the masses ..of which I am but a small part.
I have seen an example of how space time bends or warps space by the use of a ball on a rubber sheet or blanket...I am sure that anyone familar with the subject have had the example used when the concept of space time was first put to them..and indeed may have used the example to explain space time to others.
I look at that example and suspect it is misleading... to me general relativity would have the ball under the blanket. If the blanket represents a grid line I feel it is entirely placed in the wrong position...
I have placed this in general chat and hope someone can see what I am driving at and put me straight. And although moderators may feel this post should be placed in the science section I submit that given the fact I am not a scientist any discussion in the science forum could be seen as inappropriate by those frustrated by laymen trying to understand matters that may well be beyond their educational resources.
I notice that so many artist impressions follow this approach when attempting to show gravitational lensing... and to me the representation is entirely incorrect..you may notice in the many artist representations that light bends around an object where as I think general relativity would see the light bending in and then out again... that is space is bent in toward an object and bends out having passed...
Back to the ball and blanket... if we use the blanket and ball example it would mean that in a 3d (leave out the 4th as it is not relevant at this level I feel but if it is the reason the example seems around the wrong way please point it out)..sorry in a 3d representation the ball would be pushing space away and that the space time graph must therefore necessarily end at the surface of the object..planet Sun or ball..which suggests that general relativity must stop at an objects surface which I doubt is the case..
I know if I knew more I would not have to ask however I feel that such a fundamentally incorrect example should be exposed...that is on the assumption that others see the point I make and agree with my humble and simple observation or disagree and can point out where I have missed the point...
alex
alex