make me believe... 
Flat space time sounds as bad as our ancestors saying the Earth was flat, but it might just bee my understanding of it... make me believe...
make me believe...
QUOTE (bee+Oct 24 2011, 10:46 PM)
Flat space time sounds as bad as our ancestors saying the Earth was flat, but it might just bee my understanding of it... make me believe...
What don't you like about it? More than just your feelings please.
make me believe... What don't you like about it? More than just your feelings please.
Well, I dont really know anything about it so... maybe you can tell me what you like about it.
QUOTE (bee+Oct 24 2011, 11:10 PM)
Well, I dont really know anything about it so... maybe you can tell me what you like about it.
Well the first thing to do is to do a Google search and if you see the Wikipedia section on Flat space time read that and if you still have a question you will at least know as much as most on here.
Well the first thing to do is to do a Google search and if you see the Wikipedia section on Flat space time read that and if you still have a question you will at least know as much as most on here.
QUOTE (bee+Oct 25 2011, 01:46 AM)
Flat space time sounds as bad as our ancestors saying the Earth was flat, but it might just bee my understanding of it... make me believe...
No. Our ancestors had a flat earth and spherical space which they later imagined to be unbounded space. That they believed the earth to be flat was a stroke of genius in their time(I think someonoe thought as much, wiki?). The realized hills and valleys were just accidents of geography. A shift from a flat earth and spherical space to spherical earth and flat space is quite a leap to some of us. Next you'll hear of spherical prisms and cylindrical cubes.
make me believe... No. Our ancestors had a flat earth and spherical space which they later imagined to be unbounded space. That they believed the earth to be flat was a stroke of genius in their time(I think someonoe thought as much, wiki?). The realized hills and valleys were just accidents of geography. A shift from a flat earth and spherical space to spherical earth and flat space is quite a leap to some of us. Next you'll hear of spherical prisms and cylindrical cubes.
QUOTE (boit+Oct 26 2011, 03:06 PM)
No. Our ancestors had a flat earth and spherical space which they later imagined to be unbounded space. That they believed the earth to be flat was a stroke of genius in their time(I think someonoe thought as much, wiki?). The realized hills and valleys were just accidents of geography. A shift from a flat earth and spherical space to spherical earth and flat space is quite a leap to some of us. Next you'll hear of spherical prisms and cylindrical cubes.
Locally flat spacetime
Strictly speaking, the use of the Minkowski space to describe physical systems over finite distances applies only in the Newtonian limit of systems without significant gravitation. In the case of significant gravitation, spacetime becomes curved and one must abandon special relativity in favor of the full theory of general relativity.
Nevertheless, even in such cases, Minkowski space is still a good description in an infinitesimally small region surrounding any point (barring gravitational singularities). More abstractly, we say that in the presence of gravity spacetime is described by a curved 4-dimensional manifold for which the tangent space to any point is a 4-dimensional Minkowski space. Thus, the structure of Minkowski space is still essential in the description of general relativity.
In the realm of weak gravity, spacetime becomes flat and looks globally, not just locally, like Minkowski space. For this reason Minkowski space is often referred to as flat spacetime.
From wikipedia thanks
Locally flat spacetime
Strictly speaking, the use of the Minkowski space to describe physical systems over finite distances applies only in the Newtonian limit of systems without significant gravitation. In the case of significant gravitation, spacetime becomes curved and one must abandon special relativity in favor of the full theory of general relativity.
Nevertheless, even in such cases, Minkowski space is still a good description in an infinitesimally small region surrounding any point (barring gravitational singularities). More abstractly, we say that in the presence of gravity spacetime is described by a curved 4-dimensional manifold for which the tangent space to any point is a 4-dimensional Minkowski space. Thus, the structure of Minkowski space is still essential in the description of general relativity.
In the realm of weak gravity, spacetime becomes flat and looks globally, not just locally, like Minkowski space. For this reason Minkowski space is often referred to as flat spacetime.
From wikipedia thanks
QUOTE (bee+Oct 24 2011, 10:46 PM)
Flat space time sounds as bad as our ancestors saying the Earth was flat, but it might just bee my understanding of it... make me believe...
Guth shows the three possible spatial geometries and our universe spatial geometry is flat.
http://web.mit.edu/physics/news/physicsatm...2_cosmology.pdf
Figure 5 is a good illustration. Our ancesters didn't understand the Earth was spherical like the other objects they could see in the night sky. Seems like they might be able to easily deduce that but I'm not going to 2nd guess them. When they looked across the Earth it was flat.
Flat spacetime can be another discussion.
make me believe... Guth shows the three possible spatial geometries and our universe spatial geometry is flat.
http://web.mit.edu/physics/news/physicsatm...2_cosmology.pdf
Figure 5 is a good illustration. Our ancesters didn't understand the Earth was spherical like the other objects they could see in the night sky. Seems like they might be able to easily deduce that but I'm not going to 2nd guess them. When they looked across the Earth it was flat.
Flat spacetime can be another discussion.
QUOTE (brucep+Oct 26 2011, 09:53 PM)
Guth shows the three possible spatial geometries and our universe spatial geometry is flat.
http://web.mit.edu/physics/news/physicsatm...2_cosmology.pdf
Flat spacetime can be another discussion.
so flat space is not the same as flat space time?
http://web.mit.edu/physics/news/physicsatm...2_cosmology.pdf
Flat spacetime can be another discussion.
so flat space is not the same as flat space time?
QUOTE (brucep+Oct 26 2011, 09:53 PM)
QUOTE
Figure 5 is a good illustration.
IMO everything is according to the eyes of the beholder - or put in other words - is according to the perspective of the observer - the frame of the observer.
Is Earth round or flat - and the answer is yes - Earth is flat as viewed by human when standing on the surface of earth and Earth is round when viewed by human from a space vehicle.
Mother earth looks according to the mind metaphors that we humans construct in our perceiving process. Everything is soo very much anthropocentric.
QUOTE (Robittybob1+Oct 26 2011, 10:01 PM)
so flat space is not the same as flat space time?
That's a beginning discussion on relativity theory. Which is a geometric theory. Flat spacetime is described by the metric of SR. SR is the special case of a more general theory of gravity [GR] where gravitational effects can be ignored when conducting experiments. IE: the effects of gravity don't change the results of empirical tests in a meaningful way. This means there's always a segment of an objects path which can be approximated as flat spacetime and the mathematics of SR can be used to to describe events local to that path segment. Except for the GPS.
http://www.eftaylor.com/download.html#general_relativity
Chapter 1&2 is instructive on that stuff.
That's a beginning discussion on relativity theory. Which is a geometric theory. Flat spacetime is described by the metric of SR. SR is the special case of a more general theory of gravity [GR] where gravitational effects can be ignored when conducting experiments. IE: the effects of gravity don't change the results of empirical tests in a meaningful way. This means there's always a segment of an objects path which can be approximated as flat spacetime and the mathematics of SR can be used to to describe events local to that path segment. Except for the GPS.
http://www.eftaylor.com/download.html#general_relativity
Chapter 1&2 is instructive on that stuff.
QUOTE (bee+Oct 26 2011, 10:11 PM)
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