Page:Eddington A. Space Time and Gravitation. 1920.djvu/222

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206
APPENDIX

The earth's speed, , is approximately 30 km. per sec., or  1/10000 in terms of the velocity of light. The radius of its orbit, , is about 1.5 . 108 km. Hence, , the gravitational mass of the sun is approximately 1.5 km.

The radius of the sun is 697,000 kms., so that the quantity occurring in the formulae is, for the sun's surface, .00000424 or 0″.87.

Note 9 (p. 123).

See Report, §§ 29, 30. The general equations of a geodesic are .

From the formula for the line-element we calculate the three-index symbols and it is found that two of the equations of the geodesic take the rather simple form which can be integrated giving where and are constants of integration.

Eliminating and from (1), (2) and (3), we have , or writing .

Differentiating with respect to ,