According to our current understanding of physics, it is not possible for any object, including galaxies, to travel faster than the speed of light. The theory of special relativity, proposed by Albert Einstein, establishes that the speed of light in a vacuum is an absolute speed limit.
As objects move away from us in the expanding universe, the light they emit undergoes a redshift. This means that the wavelength of the light is stretched, causing it to shift towards longer wavelengths, such as infrared or radio waves. Eventually, for objects receding from us at speeds close to the speed of light, the redshift becomes so significant that the light emitted by these objects is shifted beyond the range of detectable wavelengths by our instruments.
Therefore, it is not accurate to say that galaxies "wink out" as they recede beyond the speed of light. Instead, the light they emit gets progressively redshifted to longer wavelengths, making it more difficult or impossible to observe with our current technology. However, it is important to note that even though we cannot observe these galaxies directly, their gravitational effects can still be detected and studied through their influence on surrounding objects.
It's worth mentioning that the concept of galaxies receding faster than the speed of light is a common misconception arising from a misunderstanding of the expansion of the universe. In the context of the expanding universe, the recession velocities of galaxies are due to the stretching of space itself and not due to the galaxies moving through space at speeds exceeding the speed of light.