&gt; I wonder if it would be physically possible to utilize the Earth&#x27;s extremely weak magnetic field to support any meaningful mass?<p>I bet that THERE IS YET INSUFFICIENT DATA FOR A MEANINGFUL ANSWER.<p>Have we even figured out what magnetic fields <i>actually</i> are? Magnetism, and magnetic fields, are always defined in terms of what we observe. Usually called a &quot;force&quot;.<p>For instance: Magnetism, n: &quot;a physical phenomenon produced by the motion of electric charge, resulting in attractive and repulsive forces between objects&quot;<p>Ok, fine. What is a &quot;force&quot;? That is also defined in terms of things we observe. Which is fine. But what we observe, and what something actually is, are two different things.<p>I know that Feynman said something along the lines that &quot;we question what magnetism is, but we never question the fact that your hand cannot go through a solid object&quot;. Well, I do. And that will boil down to other &quot;forces&quot; in the atoms.<p>How far have we followed that rabbit hole? I can&#x27;t find much. If you start from magnetism, you&#x27;ll be led to electromagnetism, then eventually to quantum electrodynamics. Which, from a layman perspective, just shifts which part of the phenomena we choose to handwave away. So you change from &quot;forces&quot; to &quot;interactions&quot;.<p>In the unlikely chance that there are theoretical physicists on Hacker News reading a thread about UFOs, I&#x27;d really like to get an idea how much we actually know about all this. My uneducated hunch is that there is a lot of undiscovered fundamental physics waiting for us.