As Neils Bohr showed, it is possible for electrons to move between energy levels. Light contains energy. If a photon of light strikes an atom, it is possible for the energy in the light ray to be transferred to one of the low energy electrons moving around the atomic center.
Spotting before a period is due â reasons for spotting before a period can be implantation, from a cyst or a short luteal phase and impaired egg quality. Spotting in between cycles â this is a difficult term to answer but often means your cycles are growing shorter; often with perimenopause.
Birth Control: Many women that are taking birth control will notice spotting or bleeding after her period has ended. This is caused, again, by hormonal changes caused by the birth control itself. Uterine Cysts: Cysts can form inside of the uterus and will cause post-menstrual bleeding and cramping.