i recall that some of the tightly rolled dimensions are those of a calabi - yau complex threefold, but this only accounts for 6 real dimensions. what is the 7th?
Here's a quote from The Elegant Universe that should answer that (from the notes at the back of the book):mathwonk said:i recall that some of the tightly rolled dimensions are those of a calabi - yau complex threefold, but this only accounts for 6 real dimensions. what is the 7th?
The Elegant Universe by Brian Greene said:With the discovery of M-theory and the recognition of an eleventh dimension, string theorists have begun studying ways of curling up all seven extra dimensions in a manner that puts them all on more or less equal footing. The possible choices for such seven-dimensional manifolds are known as Joyce manifolds, after Domenic Joyce of Oxford University, who is credited with finding the first techniques for their mathematical construction.
Try this: http://www.maths.ox.ac.uk/~joyce/mrrev.html. Joyce wrote a book.Moo Of Doom said:Sorry, but I don't know more about Joyce manifolds than you do. You can always Google it. Or maybe someone else on here happens to be able to explain them...
G_2 is the automorphism group of the octonian algebra. it is also one of the exceptional Lie groups that Calabi (or was it Cartan?) found could be the holonomy group of a compact, simply-connected Riemannian manifold.mathwonk said:thanks, that was very helpful, except i do not know which group G2 refers to.
i.e. apparently a joyce manifold is a compact riemannian manifold with holonomy group G2.
If that is true, how does one quantify "stationary" ? This was actually a lively debate during the creation of general relativity.Werg22 said:Does time exists if there is no movement, meaning that everything is stationnary relatively to everything?
Well, I do not quite agree on your "Addit 2" for the moment. Mathematics let you calculate spacial information indeed, but if spacetime is a dimension, then mathematics cannot represent it. That's why this dimension is split into two information; themporal and spatial. How to express spacetime in terms of mathematics? Also is spacetime absolute?meckano said:Yup, that is how I understand it.
Once you reach the speed of light:
1) time stops for you. The beginning of your light speed journey is the end.
2) you must be energy to attain that speed, no living there.
obviously there is more to decode. :)
about my bringing maths into this:
1) oops, sorry
2) I'm not a wizz, I use math to find comparisons, visualize, and then theorize.
I understand in 3D why I need:
64 1"dia. spheres to equal 1 4"dia. sphere when dealing with volume,
and only 8 2"dia. spheres
and only 2.370repeating 3"dia. spheres
So to visualize 4D I use:
256 1"dia. abc's to equal 1 4"dia. abc,
vs. only 16 2"dia. abc's
vs. only 3.16... 3"dia. abc's
and unlike cubes, the diameter is a friendly 'known' place to start.
sometimes i think cubes to visualize the ^2 ness or ^3 edness.
oops, stationary question was not for me.
well, light and gamma rays and whatnot are pretty good at defying gravity and being imparted with circular motion about something.
so I again get more appreciation for something, black holes.
- seem! to suck light back towards the living, but spits out some of it as dead gamma rays and whatnot.
I don't see math as splitting time and space.
It lets me calculate what we call spacial difference.
As I understand space, time, and spacetime, they too are people made words to try and understand what we see.
If time is tied to space, and we calculate the space, are we not calculating the time as well?
That to me is the real question about spacetime. But I'm new and unbound by higher education which invariably imposes thought constraints too.
- Not just words, I always fought the math teacher, he loved me. I did well.
-- In higher maths, there were too many unknowns for my questions to be answered in time to graduate. Now That made/makes no sense to me.
So here we all are, some great thinkers without math skills, and some great mathematicians with their thought process in 'the box'.
- I'm working my free mind towards higher education. Join me, free your mind.
oops, that's the Mars movie. :)
I just want you guys to know that this very old post isn't completely correct.Thougt of a thing, reading a topic about dimnesions...
if we think like this...
a point had 0 dimensions...
there are infinite many points in a line (which has 1 dimension)
there are infinte many lines in a square (which has 2 dimensions)
there are infinte many squares in a cube (which has 3 dimensions)
following this patterns, I see it reasonable to suggest:
that there are infinte many "cubes" (objects with 3 dimensions) in a 4 dimensional "object"...
so in an "field" (or what to call it) with 4 dimesnions we can fit EVERYTHING that we can see.. like the sun.... or maybe ven the whole univerese....
it might then be that our universe is 4 dimensional, an therfore has infinte "space" (3 dimensions).....
hope I wasnt confusing...