this post was submitted on 28 Sep 2023
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Showerthoughts
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A "Showerthought" is a simple term used to describe the thoughts that pop into your head while you're doing everyday things like taking a shower, driving, or just daydreaming. The best ones are thoughts that many people can relate to and they find something funny or interesting in regular stuff.
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Earth, water, air all have density. Meaning we can create a vehicle that can be lower destiny than the (Earth, water, air) our vehicle is riding in.
Fire doesn't have density. So we can't make a vehicle lighter than fire as fire has no density to begin with.
A rocket you say? Doesn't qualify. The rocket (when in the atmosphere) is providing lots of expanding gasses which creates a difference in air pressure pushing the vehicle forward. The rocket (when in the vacuum of space) is providing lots of expanding gasses at high velocities that we throw out of one side of the rocket causing the rocket to be thrown equally and oppositely the other direction. We have lots of engine in space which done have fire at all (nitrogen cold gas thrusters come to mind).
While fire itself may not have mass or density, the materials involved in the fire (fuel and oxygen) do have density.
In the context of a rocket engine, the combustion process involves the ejection of high-speed exhaust gases, which have mass and therefore contribute to the overall density of the vehicle.
We're in agreement on the physics of rocket propulsion. However, "fire" is essentially defined as a chemical oxidation reaction. The reaction itself doesn't have mass. While fuel and oxidizer undergo the oxidation reaction, it isn't the reaction itself providing the propulsion, its the mass and velocity of the combustion products.
This is why the "natural element" definition is old and out-of-date. Any discussion of "fire" as an element is a philosophical or literary exercise, not a scientific one.
I think you nailed it - fire is not analogous to earth, wind, and water (and heart), so the premise of the post is confounded.
I tried to imagine a vehicle for travelling on a surface of Heart, then decided I don't want to.
What if the vehicle is made out of fire? 😏