Recent content by starkind

yes, that is an excellent article, and thanks for the lead. I was interested in the torus explanation, which seems to me to attempt to answer the flat-ended cone question. However, if the structure were a torus on edge, would not the evacuated cones sides appear curved?

You have to look at the pictures. If this is two ejecta cones, there are some unanswered questions. Notice that the ejecta cones are spreading out at an internal angle of 90 degrees. I have seen no other ejecta spread like that. What kind of ejection can result in such a wide spread? Also...

further web search, there is a similar object, The Red Rectangle nebula, HD 44179, very close, I think, to the directly opposite side of the sky. Simbad shows HD 44179 at right ascension 18:21:15.94 declination -10:39, and MWC 922 at right ascension 06:20.0 declination -13:01:27.1

http://apod.nasa.gov/apod/ap070416.html http://apod.nasa.gov/apod/ap070416.html Found this yesterday on dailygalaxy.com. explanation given is that this is ejecta of two cones from a central star, seen edgewise. I am not convinced by that explanation for several reasons. My first thought...

Marcus, where could I best initiate a discussion of concepts presented in these papers? For example, the argument that time is a result of motion...it seems to me that the idea of motion already includes time, and leads to a circular argument when motion is used to define time. And ephemeral...

I noticed that too, but it could just be that we have not established basic definitions. As I keep saying, words are slippery, and of limited use in logic. however, you can find my supporting text if you go to wikipedia and search for n-sphere. I think the link was above in another post, but...

basically, yes. the ball inside a sphere has one more dimension than the sphere itself. Remember that the surface of a three dimensional ball is two dimensional, and in general a surface has one less dimension than the volume under it. if this is still confusing, think of the ocean on the...

benk99nenm312, I have to draw your attention to the meanings of words again. Your question needs to be rephrased to establish a ground upon which to address it. To review, a sphere of any dimension is the set of points equidistant from an origin point. In common language, a sphere is the...

I am not reinventing it, Apeiron, merely trying to get a better understanding. Mathematically a field is just a collection of numbers that obey certain rules of addition and multiplication. Physically we have gravitational fields, electromagnetic fields, and corn fields, as well as others. I...

I think I see that one could assign a stress value to every point in a plane, or more generally on a manifold, and that the stress value could be independent of any geometric distortion of the surface. Think of pulling on a rope that does not stretch. You can pull harder, so long as there is a...

benk99nenm312, thanks for your good wishes. Apeiron, are you talking about tensors? Vector spaces? Covector spaces? Covariance and contravariance? I am studying these things but still not entirely comfortable with them. But maybe this conversation helps my understanding. I think I...

I need time to think about this. I would normally respond now, but I got married this afternoon and my bride is waiting.

I know a way that 3-balls can be seen to self-organize into complicated structures, and I feel like I'm getting close to the maths. Wikipedia is becoming comprehensive enough now to be a useful independent study tool in learning the mathematics. Sometimes I think it would be good to discuss...

I think it is probably incorrect to say that a sphere by definition has no inside. The definition of a sphere, including an n-sphere, starts with a defined origin point, from which every point on the sphere is equidistant. That point, as far as I can see, would be 'inside', for a 2-sphere...

I am not sure CDT is entirely as you say. I have heard they start with a small but not infinitely small triangle, overlaying the manifold of interest, then in the manner of differentiation they reduce the size of the triangle to get closer approximations to the real surface, which of course is...