General Relativity concept in Upnishad
It says: पृथिव्यामाकाश: प्रतिष्ठितः , आकाशे पृथिवी प्रतिष्ठिताः
Means Akaash (Space) resides inside Earth , and earth is holded by space.

Aakash (space) resides inside earth , the space-time fabric is everywhere , inside earth too.

Again its clearly said , all planets , stars,satellites stays in akaash.
One may doubt that it is said due to akaash we hear , but the sound travel through medium like air , and not the space.
So answer is , what is sound is not known completely , it is not only pressure wave

John grib in writes regrading sound that , like a photon sound may also have a particle called phonon.
Nasa and other agencies also recorded sound of planets , that sound from is very subtle compared to normal sound pressure waves

In vaidic physics there are 4 forms of sound
Para
Pashyanti
Madhyama
Vaikhari
The sound you can easily hear is vaikhari
The sound in space is of para and pashyanti state which are very subtle , and also the cause of vaikhari and pashyanti.

@ShefVaidya @subhash_kak @davidfrawleyved @SanjeevSanskrit @mariawirth1 @jcrabtree

Answering some question , some thinks if modern science changes in future would you change your scriptures then ?
Answer- here let me tell you this space of vedas is not linked with time , while modern science link space with time and calls it space-time

So we are telling this before they changes , that the space is not linked with time , but it's independent thing.
We are not following science but we are many steps forward than it , how ?
We can also tell what is the structure of space ? What is structure of mediator particle

Which is responsible to bent or curve space , we can completely explain the process of gravity , that today science is struggling to explain it further.
We are not following science , for ex. We do not support big bang, expansion of universe through vedas.