Dr. Herzog’s Wind Clock
Ever since Einstein, scientists have understood the relative nature of time. But Dr. Theodore Herzog was the first one to commoditize time. He realized the principle of the conservation of energy was applicable to time as well. If time is sped up in one place, it must be met with a corresponding slow down of time elsewhere.
Dr. Herzog managed to commercialize his findings so that he could sell people time. Unfortunately, his wind clock never made it to market. A future version of himself came back to the present and murdered him, erasing him from the timeline all together.