D O C . 3 C O M M E N T O N N O T E B Y S C H R Ö D I N G E R 3 1

3. “Comment on Schrödinger’s Note

‘On a System of Solutions for the Generally

Covariant Gravitational Field Equations’”

[Einstein 1918d]

Received 3 March 1918

Published 15 April 1918

In: Physikalische Zeitschrift 19 (1918): 165–166.

When I wrote my description of the cosmic gravitational field I naturally noticed,

as the obvious possibility, the variant Herr Schrödinger had

discussed.1

But I must

confess that I did not consider this interpretation worthy of mention.

In terms of the Newtonian theory, the problem to be solved can be phrased

more or less as follows. A spatially closed world is only thinkable if the lines of

force of gravitation, which end in ponderable bodies (stars), begin in empty space.

Therefore, a modification of the theory is required such that “empty space” takes

the role of gravitating, negative masses which are distributed all over the interstel-

lar space. Herr Schrödinger now assumes the existence of matter with negative

mass density and represents it by the scalar This scalar has nothing to do

with the internal pressure of “really” ponderable masses, i.e., the noticeable pres-

sure within stars of condensed matter of density ; vanishes in the interstellar

spaces, does not.

The author is silent about the law according to which should be determined

as a function of the coordinates. We will consider only two possibilities:

1. is a universal constant. In this case, Herr Schrödinger’s model completely

agrees with mine. In order to see this, one merely needs to exchange the letter

with the letter and bring the corresponding term over to the left-hand side of the

field equations. Therefore, this is not the case the author could have had in mind.

1This

journal 19 (1918), pp. 20–22.

[p. 165]

[p. 1] [1]

[2]

[p. 166]

[3]

p. p

ρ ρ

p

p

[4]

p

p

λ