You always find me in the past. I am made in the present, but in the future I am nothing. What am I?

I live in the past but visit today, I color memories in a gentle way. I whisper of things that made you smile, And take you back for just a while. What am I?

I used to be part of a powerful symbol. I am also the name of fictional ninja. I can be made into jewelery and figurines.

I describe the spin of stars at night, and the sudden turn that sets a nation alight. Physics or politics, both define my name.

I’m a phantom doctors once bottled for cure. A bastion of purity, elusive and sure. Philip’s dozen penned in codices of old, Ivan and Francis each a single tale told. The first rumors of me came from the sea. The last one was written by a Beagle.