geordief

Can you fire a continuous beam of light at it and read the " reflection"? A laser radar/sonar in other words.

Yes it took a long time to sink in.

What I found hard to accept was that both parties saw the others' clocks (and general movements) as slower than each others' . Also bizarre was the finding that when the mutually moving parties were reunited the time difference accumulated did not disappear to zero. So no "optical illusion" ,but a stark reality born out by experimental observation.

How much of a difference will it make to the time discrepancies if the accelerations required for departure,turnaround and homecoming are maximized or minimized?

I didn't realize GR could\did model the expansion of the Universe. Are we getting into "Einstein's greatest mistake" territory?

It was Strange's "but not general relativity" that had me intrigued.

That seems an interesting observation . I am not sure I understand that. You can't expand ( a tiny bit) on that can you?

Space between non gravitationaly bound objects such as galaxies increases with time. I have read about the consequences of this phenomenon but not so much about the phenomenon itself. It permits objects to recede from one another at speeds higher than c,I think. Is this speed as seen from a third frame of reference or also from that of one of the objects in question? If the latter is true does that imply that these objects are (never were) not connected in the causative sense? Also ,is Inflation similar to Expansion (differing in degree and circumstance as it were) or are they completely different animals?

By "laws being different" does this just mean that values for quantities like c could have been different or might there be "qualitative" **different in the way things worked? Is our imagination the limit as to what rules the universe could play by? **"qualitative"not the right word......

Was that a philosophical observation or a scientific one?

Apparently " Psychology was once a part of philosophy, but separated from it due to its reliance on biology and the physical sciences" according to this man http://psycnet.apa.org/record/1926-03228-001 Not that I am familiar with him.

That's psychology, surely.(unless you are putting a spin on it)

When you feed the scientific (or unscientific) results back into the process in a manner like feedback or ""chewing the cud" you come up with "meta information" that could pass for philosophy. As the noted philosopher Spike Milligan KBE penned, Bigger fleas have little fleas Upon their backs to bite 'em And little fleas have lesser fleas And so on, ad infinitum

Yes I see that.(have just come to appreciate it actually). I have just realized that GR is seemingly put together using Euclidean geometry for all the buzz about its curved geometry(and arcane terminology). It reminds me of my DIY work around the house and garden. Nothing fits at first until I find a way of "making it fit"

Thanks. That will take me quite a while to (hopefully ) ingest or work around . I don't know if you have time (worthwhile time) to skim through this Youtube video (not mine of course ) to pass comment as to whether it seems rigorous. The animations seem top notch to me but if the analysis does not match up then it might be dangerous for those of us with "little knowledge". https://www.youtube.com/watch?v=UfThVvBWZxM

They are not spacetime geometries are they?

Off-linearity? Thanks to the technical staff

Wonder what that was....?

Not homework as such but I would appreciate feedback as to whether I am making progress into understanding the main principles of this theory Can I take Special Relativity as setting the stage with a "clean sheet" of flat spacetime? As I see it the main understanding in GR is that ,in a spacetime populated by massive objects at every point it is possible to find 3 2D surfaces corresponding to each spacial dimension plus the time dimension As one finds each of the 3 curvatures on these 3 surfaces (caused by the presence of nearby massive bodies or energetic effects) this overall curvature will allow one to draw a geodesic at any point which will indicate the "natural" direction of movement at the point in question Have I made any obvious errors ? Is that a decent basic understanding?

So the electron can be seen as a bearer of charge rather than originator (if that makes sense)

At what level does the magnetic "charge" originate ? " Inside" the electron?

Does that also answer Giorgio's question regarding the nucleus in this post? http://www.scienceforums.net/topic/111984-does-the-spin-of-a-nucleus-have-kinetic-energy/?do=findComment&comment=1030511 The nucleus does spin classically?

Did you read the OP carefully? Imagine an observer at the centre of an extremely curved BH. How would he "do geometry"? Similar "impossible"questions are asked regarding "flatlanders" So why cannot we ask this kind of a question too?

My question was really ;If spacetime curvature is extremely curved (as in the region of something close to a mathematical singularity ) does a new type of geometry "hove into view" quite unlike Euclidean geometry but very simple in functionality? If this geometry was understood would it be possible to derive Euclidean geometry from it in the same way as the geometry of curved spacetime is (painfully ,it seems) derived from Euclidean geometry? Might this geometry be seen as a "special case" in a mirrior image way to the way that Euclidean geometry can be seen as a "special case" of "normal" curved geometry?

Why is the term "spin" used at all in QM if it causes confusion with classical terminology? Are there any other appellations of the phenomenon?