I have a question regarding the point that determines the 1st day of Ramadan and the first day of Eid. Are these first days still determined by the physical sighting of the moon? Can it be possible that with the advancement of technology that the first day of Ramadan and Eid are determined according to the exact age of the moon according to scientific data?

Most scholars state that scientific calculations can be used to determine if there is visibility of the crescent, but actual sighting of the moon must occur because that’s their understanding of our hadiths. The hadiths seem to indicate the the moon must be visible to the naked eye (or visible in a area that shares the same horizon for example).

I recommend seeing the following videos for a better understanding of that: