To determine the mass of an object moving at a constant velocity without altering its state, one suggested method involves using two identical test masses positioned symmetrically around the object to measure their acceleration towards it. This approach relies on Newton's law of universal gravitation, where the gravitational force exerted by the object can be calculated based on the accelerations of the test masses. However, it is emphasized that some interaction is unavoidable in any real experiment, and the mass of the test objects must be known to accurately find the mass of the moving object. Alternative methods, such as measuring the bending of light beams around the object, are also mentioned. Ultimately, the consensus is that while measuring mass without any change in velocity is theoretically challenging, practical approaches can yield results with careful consideration of the variables involved.
