GRAVITATIONAL-WAVE DETECTION - A NONMECHANICAL EFFECT

We suggest attempting to detect gravitational waves through their deviating light rays that are transverse to their direction of propagation. To illustrate the existence of such a physical (coordinate-independent) effect, we derive a shift in the apparent position of stars due to an intervening gravitational pulse. The stars whose apparent positions are affected are the ones lying opposite the source with respect to the observer. Perhaps it is it a potential improvement on other methods that the effect here is not exactly an instantaneous signal to be puzzled out of the usual forest of noise, but could rather be a correlated dynamical shift in a large number of apparent star positions. Then the receding wave could be in a sense followed over a long period of time. By this we mean that, for example, one could predict when the light sources would resume their original positions, which should be when the pulse eventually moves past them. Quantitatively, the effect in the particular illustration considered here seems to be far too small for available technology, so more sophisticated realizations of this approach are needed.