Errractic moving craft seen apx 2:00, unlike any common aircraft i see on a daily basis..I am a 21 year old male. I do not take any medications other than lisinipril for blood pressure. And have been declared competitent by my peers. I was sitting outside last night, enjoying the cool night air, when a slow pulsing light caught my attention. It wasnt blinking red or green such as a normal aircraft would be. I see planes cross the sky every hour or more where there is an airport close to me. But this light moved in such an erratic pattern that I have never seen any airplane or helicopter do. Almost as if it skipped sections of the sky. It was completely silent. And my best explanation of the color would be almost an neon bluish purple. It gave me the creeps.