I was outside cleaning my pool filter (turned off), gettingvit ready for summer. it was a clear dark night, almost a half moon or just after, with no traffic noise. i was looking up and thinking about pruning my palm tree and other trees to reduce leaves in the pool, (direction of focus was upwards for about ten to 20 minutes. while looking to the east over my house, i saw what was either a hanglider size at the smallest (if it was within 150ft), or extremely large aircraft (if it was more than 500 ft, football fields size or larger), jet black triangle fly completely silent from east to west. it’s hard to explain but the visual cues were not normal. if it was low, some city street lights or building lights should have illuminated at least a little or reflected some kind of light. if it was that low, some kind of sound should have been heard. it cast a larger shadow over me and the white poolside concrete as it flew quickly over. i first thought it was a hang glider but there was nothing hanging under, it actually looked like a two dimensional triangle the entire time. it looked like it was moving around 50-70mph if it were at 150 feet above me, or way too fast, and too large for anything above 1,000 feet. it definitely wasn’t a bird, a kite, frisbee, or a drone. there was no color to it, i just saw the triangle shaped absence of light between the stars and me. it moved at a constant horizontal speed and did not change direction until i could no longer see it. the only thing other than black that i saw, was when it flew over a brightly lit parking lot/shopping center about a thousand feet west sw of me, and it was a faint orange/amber reflection from the orange lights from the parking lot. that was kind of confusing because that would mean it was too low for an aircraft and i should have been able to see at least some profile of the vertical axis. i still saw a 2d-looking isocoles triangle. but no sound other than like what you would hear if someone threw something close to you like a quiet whoosh. if it was higher up, it would have been too massive to be anything like a a normal aircraft, almost like an aircraft carrier or cruise ship size. it would also have been moving past the speed of sound... going by air show experiences only, and no sonic boom or contrails behind it. there is no place even remotely close that someone could have jumped from a stationary object to hang glide over. there’s no one i’ve even heard of that has a hang glider within 50 miles either. the guest building is the hospital about two miles away, at five stories. there were no aircraft, balloons, anywhere in the sky that night, or for at least 10-20 minutes where i was looking up. there is lemoore naval air station about 30-40 miles to the west, but they usually never come to the east. there were no lights coming from it either. there are commercial jets that fly overhead at night, but usually always north to south or south to north, but they could not be mistaken for this object. to put it quite literally, it was like someone threw a black, 20-30ft, paper airplane, from the east, and it flew just about 100ft over my head with not making any discernible sound other than air moving quietly by it. so, to sum it up. nothing tall enough to glide from nearby, drones were not popular yet for years after this time (also not personal drone shaped or sized), clear and dark sky except the moon and stars, with no other aircraft, birds, kites and a silent ambient environment. the only way to have voa better view would be to have viewed it though binoculars or telescope. it looked like it was mostly 2 dimensional, moving to fast if it was higher up, too quiet for the apparent closer distance, did not move or change shape with respect to appearance excluding direction of travel (west to slightly sw). it had no lights shining from it, and only a glint of city lights from the bottom. travelled at two or three miles or way more of it was at airplane height. i was not drinking, or doing, or under the influence of any drugs or alcohol, prescription medication or diagnosed (or not) with any previous or current mental conditions or hallucinations. i just happened to be looking up at the trees and sky on that night at the right time. i haven’t seen anything like it before or after, and really wasn’t all that exciting other than the missing obvious visual and audible sensory cues of distance and size. i don’t think anyone would ever even notice it unless they were looking for it or at least looking in the sky. i don’t have the best vision, but it’s definitely good enough to not need glasses at night to drive, and my right eye suffered moderate trauma 25 years ago when i was 8, but my vision had adapted very well.The only problem i mildly have, is objects like a baseball or similar size object coming directly at my face, or directly away.