I was just reading in that relativity book mentioned above about Minkowski space and I am not sure a sphere is the best analogy for my point I think as with light cones there is only a forward / future and back / past in visibility. I see your point that the space we inhabit is simply stretched...
I agreer 100% with your first paragraph. But- when you take this as the 3d rubber ball analogy- at the point of CMB there was nothing outside of the ball- but of course lots of matter inside. Then after it stretches -spacetime- alters the location of all the matter inside and at the "outer...
Ok after some thought and a few drawings- I am going to disagree with you Allday. Let me explain. First let me ask if CMB was emitted everywhere- how and why and what "region" are we only seeing? Now to my thoughts- First there is no "backround space" . CMB does exist everywhere in space but...
Ok, I know there is no backround static space- but- using spacetime coordinates and the recession of galaxies then the "position" of everything would change constantly on a spacetime coordinate graph so to speak.
As for the CMb- using an analogy I guess I was theorizing using the crust of...
In the Feb 2007 Astronomy magazine there is an article -Bob Berman's Strange Universe talking about shadows. At the end he talks about the lack of shadows- more specifically that Astronomers from the Wilkinson Microwave Anisotropy Probe observatory published analyses of data showing that the CMB...
Allright Allday! If this were a contest you would be a winner! That was a great explanation and example! I have had up to advanced calculus in math so it wasn't too hard to read and comprehend. Even if it has been 13 years since I have had any real use for it in my day to day life!
Along...
"I think your difficulty was that you were picturing a background static space that this expansion is happening in (which the raisin in dough model leads people to believe sometimes)"
Yes this is what I was doing. I still haven't fully resolved it in my mind- but- all I read early today...
Ok sorry this brings me to another sort of related question. The Hubble deep space pics collected light for quite awhile to get those pics. If there is a light cone and world line for each instant of light emission- how the heck is that instant caught. Wouldn't be a jumbled mess of light cone...
No, not about the speed of light at all. I totally get redshift/blueshift. It's about "position" of where light is emitted in relation to our "position" in space. Not the object moving away or space stretching- but that fact that no matter how you look at it so to speak- when using such large...
But- we are pointing at the direction of yesterday with the Hubble though- right? So aren't we in a sense including this dimension in dating and sizing the universe? Then wouldn't it alter what we think we are seeing and calculating? Especially as we don't know for sure the shape and...
I completely get what you are saying- but back to the balloon analogy. Is there no up and down or say in and out? Are all galaxies in the same plane? If the universe were a sphere And no galaxy were above or below the plane then the balloon analogy makes perfect sense to me. ( well, see below)...
I guess that's the part I am not grasping. If from our perspective all other galaxies are receding- then- from another galaxy's perspective we are in turn receding to them. Well say the universe was much smaller- say the dough for the bread- and the bread is baking our raisin is really moving...
I recently watched a show the Theory of Relativity on this with Carl Sagan- but will have to revisit it. I understand that the speed of light stays constant but if light left point A and we approached point A due to expansion as point A then grew further could the speed of expansion allow us to...
I am a bit "obsessed" with cosmology and the universe. Unfortunately, although very intelligent physics is not my strong suit. But- even the most detailed available books cannot always answer my questions and thoughts. With that said I have another question- not exactly a physics one though :)...
So if time is based atomically then a second is a second- but a "day" is said to be different on each planet based on sun and orbit. So from a different perspective in the universe then time woiuld be same. It almost seems as though it is putting us incorrectly at the center of the universe...