Could the 'Tic Tac' UFO accelerate without conventional propulsion?

I'm deeply curious about the reported capabilities of the 'Tic Tac' UAP from the Nimitz incident. From a physics perspective, how could such an object achieve those reported speeds and instantaneous direction changes without any visible propulsion system or sonic boom? Is there any theoretical science that could even begin to explain this, or are we truly looking at something beyond our current understanding?