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Joined 4 months ago
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Cake day: December 27th, 2025

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  • Think that’s weird? What about: Why do we think it’s possible to travel backwards in time, but never think about what it would mean to travel “backwards” in space? How would that even work?

    I mean, you can think about putting a car in reverse, but that’s just a human design convention. Like, a ball doesn’t have an inherent direction; no matter its motion, it’s moving “forward.” So if somehow we made a machine to reverse direction on the spacetime path of an object, what does it mean for a ball to move backwards through space?

    If the machine just changes the time component of its spacetime path, so it moves through space “forward,” with normal translation of x, y, and z coordinates, but over ⁻t, then at the instant of switching time direction, the machine is still essentially in the same spatial (x, y, z) location, and will immediately collide with its +t self going the other direction. And whatever momentum it had will encounter the same magnitude of momentum in the opposite direction, and since the Earth is spinning, the galaxy is spinning, etc., it’s going to happen with quite a bang.

    Except how can matter collide with itself? Another possibilty is that the time machine just moves back along the spacetime path along which it arrived at (x, y, z, t), like a film run backwards. Then, it would be impossible to change the past, as by switching the direction of time, the machine would be on the same deterministic path back to before we turned it on; turning it on would instantly turn it off.

    So the implicit way that time machines in fiction work is that they have to completely cease to exist (probably with a sound as if thousands of people gathered there said, “foop!”) in the universe at (x, y, z, t), and instantaneously resume existence (“whop!”) at (x’, y’, z’, t’) without passing through any intermediate coordinates. But since the Earth spins, the galaxy spins, the local galactic supercluster spins, time is all wibbley-wobbley depending on how fast you’re moving relative to other things, and there is no fixed reference point for anything, there’s no way for a time machine to lock onto (x’, y’, z’, t’), even if there was a way to get information about distant locations faster than c.

    This is about the point when I wish I was high…







  • I would say that they are democracies today, but the closest thing to a clear binary distinction between democracy and not is where sovereignty is vested. I’m most familiar with the history of the UK; nobody would say that it became a democracy once King John signed the Magna Carta, and agreed to share sovereignty with the aristocracy, but we would call it a democracy today. It is technically a hybrid system, in which sovereignty is split between the king and the people. The king approves all acts of Parliament, but it’s a formality, and the king approves whatever acts the popularly-elected Parliament passes. It was a bit-by-bit transformation from monarchy to democracy. (And it is continuing its transformation in 2026 with the abolition of the last hereditary seats in the House of Lords.)

    I get that it’s righteous to shit on the United States — because we mostly deserve it — but in this case it really was the first modern nation-state explicitly founded on pure, popular sovereignty. (As in, no monarch or aristocracy, not that everybody could vote.)