Spherical Issues

Erm we could however use longditude and lattitude to say where on the surface of the Earth the string actually is.I think co-ordiantes are an unnecessary distraction. The question is "Where is the centre of the surface of the Earth". A geographical answer would suffice (e.g. In the middle of the Atlantic ocean).The point being made is that there is no such thing as the centre of the surface of a sphere. It is a meaningless question. Hence the fact that you are unable to answer it.Edited by Straggler, : No reason given.

You are not making any sense.How can the surface of a sphere have a centre? No matter what co-ordinates you use?If you are going to insist on co-ordinates when applying this to the surface of the Earth then longditude, lattitude and radius from the actual centre of the Earth (i.e. the Earths core) would be required to pinpoint an exact position but if the centre of the surface is actually on the surface then the radial co-ordinate is hardly necessary.
Even with these I fail to see how you can define the centre of the surface of a sphere?How can an unbounded surface have a centre?Are you confusing the centre of the Earth (i.e. the centre of a 3D sphere) with the centre of the surface of a sphere (i.e. an unbounded 2D "landscape")Edited by Straggler, : No reason given.

Good grief. Are we still debating this? Apparently so. The surface of a sphere has no centre. Obviously.
Forget the Earth for a moment. Forget co-ordinates for a second.Pick up a basketball. Point to where you think the centre of the surface of this sphererical object is supposed to be.
Not the centre of the sphere. The centre of the surface of the sphere.Where is the centre of the surface of a ball? There isn't one. Obviously.You used the example of a circle earlier on. Obviously a circle does have a centre (in the same sort of way that a sphere has a centre). But does the outline of a circle (i.e. the line that defines the boundary of a circle) have a centre? If so where is it?Imagine yourself running around a single lane running track suspended in space. At which point in your run do you cross the 'centre' of the track?
Now imagine a giant ball suspended in space. A ball large enough for you to stand on and run around on in all directions. If asked to run to the centre of this surface where would you go?The line that defines a circle has no centre. The surface that defines a sphere has no centre.Why is this so hard for you?

So where exactly is the centre of the surface of a basketball?
Can you hold a basketball in your hand and actually point to this centre of the surface?I am willing to bet my life on the fact that you cannot.Other than insist that there must be a centre you have said nothing that makes any sense regarding where this supposed centre actually is.
The centre of a sphere can be shown visually and mathematically.
If the centre of a surface of a sphere actually exists (as you repeatedly insist) why can you not show us this centre (visually or mathematically)?

If you existed in dimensions seperate to, and different from those of the universe itself and were (somehow) standing outside of the universe on the surface of the universe (whatever that is) looking "up" then I can confidently state with the full authority of absolute knowledge that......You would be looking directly up Odin's sweaty arsehole.Cheers (or skulls up as they say in Valhalla)Edited by Straggler, : No reason given.

Mathematically we can describe many things that we can not actually picture or fully conceive. A 10 dimensional universe for example. We can describe things that do not,as afar as we know, physically exist (e.g. a universe without gravity)
We can mathematically define the centre of a sphere, a triangle, a square, a cube etc. etc.
An unbounded suface however has no centre. Neither mathematically nor one that can be derived from 'common sense'This is not a lack of imagination on our part IAJ. Mathemantics can perfectly well describe many shapes and surfaces that we are utterly incapable of imagining.The centre of a surface of a sphere does not exist mathematically and it does not exist in actuality.No matter how firmly you wish to beleieve otherwise this is a fact. It is because this is a fact that you are utterly incapable of defining the centre of a surface of a sphere. Either in practical or abstract terms.

The bottom line here is that you can neither show us where the centre of an actual physical spherical surface really is. Nor can you describe this in abstract or mathematical terms.
In both theory and practice your point of view falls apart.On what basis do you claim that this centre actually exists?It seems to me that your whole argument amounts to - "I think everything has a centre therefore the surface of a sphere must have a centre. I am incapable of believing otherwise no matter what conceivable evidence, argument or even mathematical proof there is that the opposite is true"

Yes IAJ. If you take a basketball, cut it in half and then flatten each of the two circles of rubber that you are left with, each of the "circles" will indeed have a centre.
However it may have escaped your notice that you are no longer left with the surface of a sphere. You now have two circles. Each with a centre.By the bizzare law of "conservation of centres" that you seem to be alluding to, our original ball must have had two centres if we can produce two centres from the cutup material?
But wait!!!! We can cut again!!! We can produce a plethora of shapes from the rubber that made the original basketball surface and end up with no end of centres.Great scott!! Where did all of these centres come from? What magic is occurring here?If I cut a paper square (with one centre) in half I will get two rectangles (and thus two centres). Where did these mysterious centres come from?Could it be that your "law of conservation of centres" is just really quite silly?

Brillaint!! But unless you can tell me what I would see if I stood on the surface of the infintely dimensional volume of the supreme spherical hot dog (with relish) and looked upwards - you will have been utterly refuted.Obviously.

IAJ Writes IAJ you are inventing meanings for words as you go along.If you are going to get into actuals vs academics you should also factor in the fact that there is no such thing as an actual sphere. Rough approximations to the ideal of a mathematically defined sphere exist but a perfect sphere with each point equidistant from the centre is but an abstract concept not found in reality.The Earth is a lumpy "sphere". A Basketball is a slightly squashed knobbly "sphere".Where does that leave you with regard to "actuals and academics"? No it is you confusing the two. Endelessly.
A sphere has a volume. This volume has a point that is equidistant from every point on the boundary of this volume. We call this point the centre of a sphere. We measure volumes in terms of cubic capacity. Things with volumes are 3D objects.The boundary of the 3D sphere itself is called the surface of the sphere. This is two dimensional and has an area NOT a volume. This surface is unbounded. Whichever direction you go on this 2D surface you will never reach an edge or a boundary. On this surface there is no point that is equidistant from every boundary because there are no bounadaries.The volume and the surface are very diferent (although mathematically related) entities. They are measured differently and have different properties.
Confusing and conflating the properties of a 3D sphere with the properties of a 2D surface is exactly like adding 2 miles to 3 gallons and coming up with 16 square acres.I.e. silly. Obviously silly.

This is a genuine attempt to explain the concepts that seem so obvious to many of us but which you seem genuinely to dispute.
You do not have to agree but at least hear this out before commenting.Imagine a ball of putty (or any other soft malleable material you can think of)
This ball is 3D solid and spherical
Imagine that you are a particle within this putty. A particle that can move around within the putty but never actually leave the putty.
You can travel to the centre of this ball
You can travel anywhere you want within the ball.
But whichever single direction you go in you will eventually reach the end of the putty and be able to travel no further in that direction
You will reach the boundary of the putty sphereNow we squash the putty ball flat. Completely flat.
You are still a particle in the putty and you can still move within the putty
But now our putty is a circle
You still cannot leave the putty so now your motion is restricted to two dimensions. There is effectively no “up” or “down” just forwards, backwards and sideways in either direction.
You can travel to the centre of this circle
You can travel anywhere you want within the circle.
But whichever single direction you go in you will eventually reach the end of the putty and be able to travel no further in that direction
You will reach the boundary of the putty circleNow we place our flat putty circle on top of a perfectly spherical balloon
We blow the balloon up
Then we pop the balloon and remove the balloon leaving a perfectly spherical flat layer of putty
You are still a particle in the putty and you can still move within the putty
But now our putty is the surface of a sphere
You still cannot leave the putty so your motion is still restricted to two dimensions. There is effectively no “up” or “down” just forwards, backwards and sideways in either direction.
You can travel anywhere you want within this spherical surface
You can travel in any one direction forever. You will never come to a boundary. You may well come back to the point you started but you will never reach the end of the putty and there will be no barrier to your motion.
Can you locate the centre?This is what we mean by the surface of a sphere.
This is what we mean by no boundary
This is what we mean when we say that the surface of a sphere has no centre.Please. Think about it.

OK. If you are incapable of thinking in 2D try this.The "thickness" of the putty is one particle thick.
You, inside the circle of putty are also one particle thick because you are one of those particles that make up the putty.No mass has been lost. The putty has just been squashed to it's actual physical limit of one particle thick.As a particle in that putty your motions are as restricted as they would be in an imaginary 2D situation.Now consider the 1 particle thick hollow sphere of putty and tell me where the boundaries are and where the centre is.

Exactly as you predicted.Does post 183 above counter this?

No we don't. There are 2 dimensions. The surface has an area.When we measure the surface area of a sphere in cm squared what does this number mean to you?Are you claiming this is not a real measurment? That the surface area of a sphere is a made up quantity?If I asked you to paint a ball what measurement would you ask for to work out how much paint you needed to do this?

Are you now saying that a sphere has infinite centres?