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## Main Question or Discussion Point

Hi there,

I have a few queries and they are as follows:

(i) What is the difference between the Einstein metric and the Space-time metric?

(ii) What does the curvature of the metric really mean? Does one calculate the Riemann curvature tensor, but what does that really tell you if it ends up 'a constant divided by r squared'?

(iii) In the context of string theory, why is it that the space-time metric ceases to be well defined once the curvature of the string metric is of order the string scale?

I have a few queries and they are as follows:

(i) What is the difference between the Einstein metric and the Space-time metric?

(ii) What does the curvature of the metric really mean? Does one calculate the Riemann curvature tensor, but what does that really tell you if it ends up 'a constant divided by r squared'?

(iii) In the context of string theory, why is it that the space-time metric ceases to be well defined once the curvature of the string metric is of order the string scale?