"Swaczyna used SWAP’s measurements to derive the density of neutral hydrogen at the termination shock, where the solar wind butts up against the interstellar medium and abruptly slows down. After months of careful checks and tests, the number they found was 0.127 particles per cubic centimeter, or about 120 hydrogen atoms in a space the size of a quart of milk.
This result confirmed a 2001 study which used Voyager 2 – about 4 billion miles away – to measure how much the solar wind had slowed by the time it arrived at the spacecraft. The slowdown, largely due to intervening interstellar medium particles, suggested a matching interstellar hydrogen density, about 120 hydrogen atoms in a quart-sized space."
https://www.nasa.gov/feature/goddard/2020/new-evidence-our-neighborhood-in-space-is-stuffed-with-hydrogen
"At the orbit of the earth the average solar wind consists of a strongly ionized gas having a proton and electron density of about 3 - 10 particles per cubic centimeter, with an average flow velocity of approximately 400 km/s. Occasionally stream structures are detected in the steady solar wind, which have peak velocities which tend toward a mean of about 750 km/s near the earth. Occasionally impulsive events are detected with peak velocities in excess of 1000 km/s."
https://umbra.nascom.nasa.gov/spartan/the_solar_wind.html
"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/
"Plasma react very strongly to electromagnetic forces, and is the dominant force in many cosmic plasmas, e.g. stellar surfaces, active galactic nuclei, and, interplanetary, interstellar and intergalactic space"
"Space plasma moving through a magnetic field generates its own electric current, can act as a unipolar inductor, and it conducts electricity better than metals, e.g. the heliospheric current sheet above, and Birkeland currents."
https://www.plasma-universe.com/
"Electromagnetic energy travels in waves and spans a broad spectrum from very long radio waves to very short gamma rays"
"Our Sun is a source of energy across the full spectrum, and its electromagnetic radiation bombards our atmosphere constantly."
https://science.nasa.gov/ems/01_intro
"Electromagnetic radiation can be described in terms of a stream of mass-less particles, called photons, each traveling in a wave-like pattern at the speed of light. Each photon contains a certain amount of energy"
"Electromagnetic radiation can be expressed in terms of energy, wavelength, or frequency. Frequency is measured in cycles per second, or Hertz. Wavelength is measured in meters. Energy is measured in electron volts. Each of these three quantities for describing EM radiation are related to each other in a precise mathematical way. But why have three ways of describing things, each with a different set of physical units?"
https://imagine.gsfc.nasa.gov/science/toolbox/emspectrum1.html
"The average temperature of outer space near Earth is 283.32 kelvins (10.17 degrees Celsius or 50.3 degrees Fahrenheit). In empty, interstellar space, the temperature is just 3 kelvins, not much above absolute zero, which is the coldest anything can ever get."
https://sciencing.com/temperatures-outer-space-around-earth-20254.html
"The amount of heat in a substance is the total vibrational energy of all the atoms and molecules that make up the substance."
"Heat is the energy an object has because of the movement of its atoms and molecules which are continuously jiggling and moving around, hitting each other and other objects. When we add energy to an object, its atoms and molecules move faster increasing its energy of motion or heat. Even objects which are very cold have some heat energy because their atoms are still moving."
https://coolcosmos.ipac.caltech.edu/page/lesson_moving_molecules
"The aether exists and it is the medium for propagating light and other longitudinal and transverse (electromagnetic) waves across the universe. It is the fabric of our universe, consisting of tiny granules that transfer energy in the form of waves. Its structure and properties were worked out in the section on spacetime. In fact, it has a density property in the wave constants that appears in all of the energy wave equations. Without an aether, or without this density property, none of the calculations performed in this theory would be possible."
https://energywavetheory.com/explanations/aether/
"His theory claims to explain the missing 95% of the observable universe by the existence of "dark fluid"."
https://bigthink.com/hard-science/astrophysicist-dark-fluid-missing-95-percent-universe/
""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".
"We also predicted other weaker dissipative effects, which we might be able to see with future astrophysical observations."
https://phys.org/news/2014-04-liquid-spacetime-slippery-superfluid.html