Because empty space cannot propagate sound.
1604.
There have been several recorded supernovae in the Milky Way. The earliest recorded Milky Way supernova was SN 185 (seen, as the name implies, in 185 C.E.), and the most recent supernova recorded was SN 1604 (seen in 1604 C.E.), or Kepler's Supernova.
Kids are both to be seen and heard
Supernova explosions are incredibly bright and release vast amounts of energy, making them visible across great distances in space. However, sound requires a medium, like air or water, to travel through. In the vacuum of space, there are no air molecules to carry sound waves, so while we can see the light from a supernova, we cannot hear it on Earth.
Music or sound is something that can be heard but not seen.
Because it IS a supernova remnant. It's the visial remains of a star that expolded and was seen in 1054. Designated SN 1054.
SN 2006gy [See Link] was an extremely energetic supernova that was discovered on September 18, 2006. Although about one hundred times as luminous as SN 1987A, which was bright enough to be seen by the naked eye, SN 2006gy was more than 1,400 times as far away as SN 1987A, and too far away to be seen without a telescope.SN1987A [See Link]was a supernova in the outskirts of the Tarantula Nebula. It could be seen with the naked eye from the Southern Hemisphere.It was the closest observed supernova since SN 1604 The light from the supernova reached Earth on February 23, 1987.SN1604 [See Link] was seen on October 9th, 1604 generally a supernova occurs once every fifty years but the universe has been in a drought for these supernatural awesome events
SN 2006gy was an extremely energetic supernova that was discovered on September 18, 2006. Although about one hundred times as luminous as SN 1987A, which was bright enough to be seen by the naked eye, SN 2006gy was more than 1,400 times as far away as SN 1987A, and too far away to be seen without a telescope.SN1987A was a supernova in the outskirts of the Tarantula Nebula. It could be seen with the naked eye from the Southern Hemisphere.It was the closest observed supernova since SN 1604 The light from the supernova reached Earth on February 23, 1987.SN1604 was seen on October 9th, 1604 generally a supernova occurs once every fifty years but the universe has been in a drought for these supernatural awesome eventsSN1987A was a supernova in the outskirts of the Tarantula Nebula. It could be seen with the naked eye from the Southern Hemisphere.
She is heard but never seen: Heard in (How to Spank A Star; season 3)
Water is possibly the only thing that can not be caught but can be seen and heard.
It's seen & NOT heard- It means they should not interfere in adult conversation.