In this hypothetical scenario where 'aether-sonis' permeates the vacuum of space and can perfectly transmit vibrations, the experience of an explosion from the cockpit of a nearby spaceship would be quite different from what we expect in our reality, but also significantly different from what is usually portrayed in science fiction movies.

### Visual Experience

Upon the explosion of the other spaceship, the visual cues would be the first to reach the observers in the nearby ship's cockpit. Light, traveling at approximately 299,792,458 meters per second in a vacuum, would reach the observers virtually instantly, considering the distances typically involved in space battles as depicted in movies. The observers would see a bright flash as the explosion converts the ship's matter into various forms of energy, including light. The absence of air means no fireball in the traditional sense, but there could still be a rapidly expanding field of debris and incandescence from the explosion itself, depending on the specifics of the ship's materials and the cause of the explosion.

### Auditory Experience

The truly fascinating difference in this scenario, enabled by the presence of 'aether-sonis', is the transmission of sound through the vacuum of space. Assuming 'aether-sonis' can transmit vibrations perfectly across any distance instantly or at the speed of light (since it's a hypothetical scenario, we can entertain the idea of instantaneous transmission or even superluminal transmission for the sake of argument), the explosion's sound would reach the nearby spaceship simultaneously with the light. This is because, in this imagined universe, the 'aether-sonis' does not adhere to the ordinary limitations of sound transmission through a medium, such as delay due to the speed of sound (~343 meters per second at sea level on Earth).

The crew would hear a shocking, sharp, and possibly deafening noise at the same moment they see the flash of the explosion. This sound would not be filtered or muffled by the atmosphere, so it might be incredibly clear and detailed, unlike anything heard through air or water on Earth. The explosion's characteristics, such as the ship's materials, the size of the explosion, and the nature of the 'aether-sonis' itself, would determine the sound's pitch, volume, and other qualities. It's also worth considering that this perfect transmission of sound might include frequencies far outside the human auditory range, adding layers of experience that could be both fascinating and potentially hazardous to the observers.

### Simultaneity and Physics

In this hypothetical scenario, the observers would see and hear the explosion simultaneously (or nearly so, with a slight delay for light and potentially no delay for sound, depending on how you define the properties of 'aether-sonis'). This defies our current understanding of physics and the speed at which sound and light travel. The experience of simultaneity, or near-simultaneity, of light and sound from an explosion in space would be surreal and is made possible by the imagined properties of 'aether-sonis'—a massless, invisible matter that permeates the entire vacuum of space and perfectly transmits vibrations.

This scenario raises intriguing questions and challenges our fundamental understanding of physics and sensory experiences in the vacuum of space, blending reality with imaginative elements to create a truly unique experience in the cockpit of the observing spaceship.