Curvature Of Spacetime

[sonu]

I came across theory of relativity and was reading about it on internet.i came to know that space and time are related and space-time is curved.how can space(just a notion)can curve?how can time be curved.when i googled it i got information that there is some geometrical representation for this.Is there a proof for this?if you make a geometrical representation,does that mean space and time which are nothing but notions are curved? PLEASE NOT SO MUCH COMPLICATED ANSWERS AS I AM ONLY 15.

Edited February 26, 2012 by sonu

[sonu]

why am i not getting reply?does this question make no sense to you?

[Lancewen]

I came across theory of relativity and was reading about it on internet.i came to know that space and time are related and space-time is curved.how can space(just a notion)can curve?how can time be curved.when i googled it i got information that there is some geometrical representation for this.Is there a proof for this?if you make a geometrical representation,does that mean space and time which are nothing but notions are curved? PLEASE NOT SO MUCH COMPLICATED ANSWERS AS I AM ONLY 15.

 

Okay I'll give it a shot. Spacetime by itself is not curved. It curves or warps in the presence of mass. The more mass the more spacetime warps or curves. This warping or curving of spacetime is responsible for what we call gravity. Now if you want to know how this happens, I would suggest you become a scientist and make finding out your life's work.

[sonu]

Okay I'll give it a shot. Spacetime by itself is not curved. It curves or warps in the presence of mass. The more mass the more spacetime warps or curves. This warping or curving of spacetime is responsible for what we call gravity. Now if you want to know how this happens, I would suggest you become a scientist and make finding out your life's work.

Thanks for reply arkane.As you told mass curves space,but still my question remains that how can mass curve space?we know that space is not a matter,it is other than matter(just a notion),then how can it be curved?

[Lancewen]

Thanks for reply arkane.As you told mass curves space,but still my question remains that how can mass curve space?we know that space is not a matter,it is other than matter(just a notion),then how can it be curved?

 

I haven't got a clue and I don't know anyone else that does either. Maybe you are looking for someone with a pet theory about it. If this science forum doesn't have anyone I know a few others you can try.

Edited February 27, 2012 by arKane

[Qfwfq]

does this question make no sense to you?

It does to me and it does to a few other people, including Steven Wienberg. Unfortunately, many people overlook it (and Einstein did too, somewhat, although not totally).

 

First you need to understand what is meant by this spacetime curvature, but it is a complicated thing. Differential geometry is an excellent tool for describing gravitation, regardless of whether the curvature is an actual fact about spacetime. However, what counts is called the intrinsic curvature so let me show you what I mean by saying this:

 

Take a piece of paper and roll it up. You will probably say it is curved, now that you have rolled it up, but I will tell you that it has an intrinsic curvature of zero.

 

Now suppose you need to fly an airplane from Paris to Hong Kong and you want to take the shortest possible path. Hmmm, authorities might not let you because there are air traffic corridors but let's forget about that, certainly you can't fly underneath the ground; the shortest path between the two places is called a geodesic and it is exactly what you would mean if you talk about "flying straight" over long distances. So, let's call these paths straight lines and use them just like in a geometry class at your school. If you make a triangle with them, the angles sum up to more than 180° and you can see this by considering the case of the north pole and two points along the equator; the angles at these two points alone add to 180° already and the angle at the pole is extra! Some other things are unlike the flat geometry that you may have learnt in school. For instance if you take a centre (the north pole, say) and trace out all points at an equal distance to it, you get a circumference which is a bit less than [imath]2\pi[/imath] times that distance. Of course, if you take the distance of these points from the north-south axis, you have the exact usual ratio of flat geometry, but the distance to the pole, along the sruface, is greater. This greater denominator makes for the ratio being less.

 

Now the above has nothing to do with gravitation, that's not what general relativity is, but I hope it helps you understand what I mean by intrinsic curvature. If we were unaware of altitude and could only measure angles and distances over ground, we could nevertheless figure out the intrinsic curvature without seeing the 3D spherical shape of our world. It can also be put as follows: a flat sheet of paper that doesn't stretch can't be exactly wrapped around the globe, you would need to take an elastic sheet and stretch it around it.

 

Understanding gravitation with differential geometry is more complicated than this, but your question shows that you are already able to think about these things so, do math as well as you can at school, including calculus, then when you are older maybe you will be studying modern physics or at least understanding it more easily.

[belovelife]

curved space, gravity

 

curved time, relative speed

 

?

curved space

 

gravity

 

magnetism

 

space/time bend

 

?