Concepts In Theoretical Physics - General Relativity

# Concepts In Theoretical Physics - General Relativity -...

This preview shows pages 1–8. Sign up to view the full content.

Concepts in Theoretical Physics David Tong Lecture 7: General Relativity

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Gravity is Geometry
Inertial and Gravitational Mass s Mass arises in two different formulae, both due to Newton b Gravitational Mass: b Inertial Mass: s Yet the meaning of mass in these two formulae is very different. F = ma F = GmM/r 2

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Inertial and Gravitational Mass s Mass arises in two different formulae, both due to Newton b Gravitational Mass: b Inertial Mass: s Yet the meaning of mass in these two formulae is very different. s We should really distinguish between the two masses by calling them something different. F = m I a F = Gm G M G /r 2
Inertial and Gravitational Mass s Mass arises in two different formulae, both due to Newton b Gravitational Mass: b Inertial Mass: s Yet the meaning of mass in these two formulae is very different. s We should really distinguish between the two masses by calling them something different. s Experimentally, we find F = m I a F = Gm G M G /r 2 m I = m G To an accuracy of 1 part in 10 13

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Inertial and Gravitational Mass s The equality of inertial and gravitational mass is responsible for the well known fact that objects with different mass fall at the same speed under gravity. s According to legend, this was demonstrated by Galileo dropping farm animals from the leaning tower of Pisa. s But is there a deeper reason why the gravitational force is proportional to the inertial mass?
s There are two other forces which are also proportional to the inertial mass. These are b Centrifugal Force: b Coriolis Force: s But in both of these cases, we understand very well why the force is proportional to the inertial mass, m. It follows because these are “fictitious forces”, arising in a non-inertial frame. (In this case, one that is rotating with frequency ) s Could gravity also be a fictitious force, arising only because we are in a non-inertial frame? The answer, of course, is yes! F

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 02/07/2011 for the course PHYS 101 taught by Professor Aster during the Spring '11 term at East Tennessee State University.

### Page1 / 21

Concepts In Theoretical Physics - General Relativity -...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online