Yes, time dilation can affect how we view speeds in galaxies. When observing distant galaxies, the light we receive from them carries information about their motion and properties. However, due to the effects of time dilation, the perceived speeds of objects in those galaxies may differ from what we would expect based solely on their motion.
According to special relativity, when an object is moving relative to an observer, time dilation occurs, causing time to appear to pass more slowly for the moving object. This effect becomes significant as the relative velocity approaches the speed of light. As a result, when we observe objects in distant galaxies, their perceived speeds may be affected by time dilation.
For example, let's say there is a galaxy moving away from us at a significant fraction of the speed of light. Due to the time dilation experienced by objects within that galaxy, the processes and events happening in that galaxy would appear to be occurring more slowly compared to an observer in a stationary frame of reference. This means that the perceived speeds of objects within the galaxy would also be affected.
As a consequence, the observed redshift of light emitted by objects in the moving galaxy would be influenced by time dilation. Redshift is a phenomenon where light waves get stretched, causing a shift towards longer wavelengths, which corresponds to objects moving away from us. The combination of the actual motion of the galaxy and the time dilation effect can affect the redshift and perceived speed of objects within the galaxy.
It's important to note that the effects of time dilation on galaxy speeds are typically considered when dealing with extremely high velocities close to the speed of light, such as in the context of cosmological observations and relativistic astrophysics. For most nearby galaxies or galaxies moving at speeds much lower than the speed of light, the impact of time dilation on observed speeds is negligible and can be safely ignored for practical purposes.