Musing of an old engineer - Explaining gravity as the result of a mass traveling though a medium (space-time) using traditional fluid dynamics
The idea that space-time is a medium is interesting but for the most part not taken into consideration when formulating therories to explain what happens when massive objects, well all objects but the effects for massive objects are large enough to be observed and explained, interact with space-time. We explain things around us using observations then characterizing the observations using science (physics and mathematics). However, we are part of the system which we are observing and trying to characterize. It seems that most of unique the ideas about science put forward in the 19th and 20thcenturies were initialialy proposed as thought experiments in order to escape this paradox, i.e. we are part of the system we are trying to explain. An example of this is Einstein’s thought experiment about the sound of a train whistle when the train is approaching, when it is next to you, and when it is traveling away from you. The speed of the train effects the wavelenght of the sound produced by the train whistle relative to what one hears as a stationary listener. Einstein used this observation to propose that the same thing happens to the wavelenght of visible light observed by a stationary observer in that the observed visible light will shift from shorter wavelenghts for objects moving toward you to longer wavelenghts for objects moving away from you. This is referred to as the “Doppler Effect” and was used by Hubble to conclude that the universe is expanding due to observed light having a red-shift for the stars / galaxies observed. The point is that we are trying to understand things in the universe around us through observation while we are part of ths system we are observing. To make strides in our understanding of the system we trying to understand while being part of the system we have to attempt to act as true observers by removing ourselves from the system by using what Einstein charaterized as a thought experiment. My thought experiment here is an attempt to expand Einstein’s therories about relativity by expanding the view as an observer watching objects, the sun, earth, etc. as a stationary observer move past me through the medium of space-time.
What is the medium of space-time? In the past 40 years we have started to relalize that space is more than just an empty vacume of nothing. It is composed of matter and sub-atomic particles which we just beginning to characterize. Space is essentially a complex medium which we are traveling through at a high velocity with the sun and the rest of the stars in the Milky Way galaxy. What if Einstein’s theories about relativity were cast using this point of view? The sun is a massive object moving through space-time at a high velocity and displacing the medium of space-time. The displacement of space-time creates a vortex. This vortex could characterize the curvature of space time due to the sun’s mass and velocity. The motion of the earth and other planets orbiting around the sun could then be characterized using this approach. The first take away from this thought experimant is, would the sun have what we call gravity if it was not moving through space-time? Furthermore, would the earth have gravity if it was not moving through space-time?
Traditional fluid dynamics characterizes fluids as either a liquid or a gas. Recently another fluid category has developed called plasma which is a fluid meduim not composed of atoms or molecules but of charged particles (ions and/or electrons). Liquids are typically represented to be incompressible, i.e. have a constant density independent of temperature and pressure. The properties of gases are repesented using what is called the “ideal gas law” or “PV=nRT” which is the gas’s pressure times it’s volume is equal to the number of moles (atoms/molecules) of gas times the gas temperature and the “ideal gas constant”. This law is used to characterize the property of most gases accurately. Some gases, e.g. Hydrogen, have properties which don’t conform well to this law.
Traditional fluid dynamics categorizes fluid flow using two chategories, laminar and tubulent. Laminar fluid flows are smooth and streamlined whereas turbulent fluid flows are irregular and chaotic. The type of fluid flow is determined by the density of fluid, the velocity the of fluid flow, and the fluid’s viscosity. A fluid’s viscosity represents the resistence to the fluid’s flow at a given density, velocity and temperature.
Based on the “ideal gas law”, a gas’s density, i.e. the mass of the gas occupying a specific volume and temperature, increases at lower temperatures. The baseline temperature of the space-time medium using the microwave backround radiation from the big bang is 2.7 kelvin (-270.45C, -454.81F). Because the density of normal matter in the space-time medium, i.e. outer space, is very-very-very low, increases in both the density and viscosity of the space-time medium at 2.7 kelvin, space-time fluid flows will most likely be represented using laminar flow using traditional fluid dynamics. Characterizing how the sun deforms space-time at a velocity of 251km/s while orbiting the center of the Milky Way galaxy using laminar flow decreases the complexity of models generated via fluid dynamics. Because the density of the space-time medium is very-very-very low, extending traditional fluid dynamics to model this medium doesn’t appear to be a viable approach.
However, the results of modeling performed to characterize the “quantum vacuum” of space-time has represented the space-time medium as a boiling sea of appearing and disappearing particle pairs. This presents the opportunity to represent the space-time medium as a fluid of both the very-very-very low matter density and the particle pair background activity interacting with objects passing through it at high velocities. The consequence of being able to extend fluid dynamics to repesent how objects like the sun are passing through the space-time medium and deforming it and effecting how other objects are traveling through space-time, e.g. the planets orbiting the sun, may extend our understanding of space-time, gavity, dark matter, and dark energy.