"Maybe there was some strange kind of energy-fluid that filled space."
https://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy
"A plasma is a fluid, like a liquid or gas, but because of the charged particles present in a plasma, it responds to and generates electro-magnetic forces."
https://www.grc.nasa.gov/WWW/k-12/airplane/state.html
"A plasma (often ionized gas, but see Pseudo-plasma), is a gaseous substance consisting of free charged particles, such as electrons, protons and other ions, that respond very strongly to electromagnetic fields. The free charges make the plasma highly electrically conductive, so that it may carry electric currents, and generate magnetic fields."
https://www.plasma-universe.com/Plasma/
"Solar wind is what's known as a plasma, a heated gas made up of charged particles — primarily protons and electrons, with trace amounts of heavier elements such as helium and oxygen. The amount of heavy elements and their charge state, or number of electrons, differ between the two types of wind."
https://www.nasa.gov/feature/goddard/2016/swept-up-in-the-solar-wind
"99.9 percent of the Universe is made up of plasma," says Dr. Dennis Gallagher, a plasma physicist at NASA's Marshall Space Flight Center. "Very little material in space is made of rock like the Earth."
https://science.nasa.gov/science-news/science-at-nasa/1999/ast07sep99_1/
"If spacetime is a fluid, then according to our calculations it must necessarily be a superfluid.
‘This means that its viscosity value is extremely low, close to zero."
https://www.dailymail.co.uk/sciencetech/article-2612949/Are-living-underwater-Researchers-believe-universe-liquid-superfluid.html
"Dark energy makes up 68%, about two-thirds, of the universe."
https://spaceplace.nasa.gov/dark-matter/en/