The Andromeda Galaxy, also known as Messier 31, is located approximately 2.537 million light-years away from Earth. Since nothing can travel faster than the speed of light in a vacuum, we can use the speed of light as a constant to calculate the time it would take to reach the Andromeda Galaxy.
If we assume a constant speed of light, it would take approximately 2.537 million years to reach the Andromeda Galaxy. This calculation is based on the assumption that you could somehow travel at the speed of light, which is currently not possible with our current understanding of physics.
It's important to note that as an object with mass approaches the speed of light, its relativistic mass increases, requiring more and more energy to continue accelerating. Additionally, time dilation effects would occur, making the journey seem shorter for the traveler. However, these factors do not change the fact that it would still take millions of years from an outside observer's perspective to reach the Andromeda Galaxy at the speed of light.