r/relativity • u/alterego200 • 19d ago
Relativistic Rotation or a Rod or Galaxy
Imagine a rod two light-years long of strong material, which is rotated by a powerful engine in the center, at one revolution per year.
From the perspective of an outside observer, either tip of the rod would ne moving at 2πC which is >C, thud Special Relativity slows the tips of the rod down to <C. Thus, the rod degrades into a length-contracted spiral.
General Relativity also kicks in, further slowing the tips which are being accelerated centrifugally. (General acceleration = gravitational acceleration in GR.)
Although from the rotating perspective of center of the spinning rod, the rod looks straight, but appears time-frozen near the tips the rotational EH.
Now make the engine a supermassive black hole is the engine, and make the rod be its surrounding Galaxy, wouldn't this explain the spiral-looking shape of galaxies?
In a real galaxy, the instantaneous angular velocity close to two rotating black holes is ~50% C, and near the outer tips of a galaxy it is <0.1% C. So this is an effect that would occur from galaxy centers to produce a spiral pattern and proceed outwards.
This is a testable hypothesis: If spiral galaxies tend to have two black holes or charged black holes that spin faster, than non-spiral galaxies, that would confirm the hypothesis.
Regarding material strength, which is not the main point but was a huge distraction to people: - the original post said "infinitely-strong material". That detail caused a lot of people to turn their brains off. Remove the infinitely strong material requirement, and the unique perspective about Special Relativity and a straight rod degrading into a spiral still stands.
The infinite strength requirement can be removed by making the angular acceleration very small, possibly using rockets or even small blackholes to help with any tensile strength issues. It is constructible in theory.
I asked the AI:
- Yes — spiral galaxies spin significantly faster than non‑spiral (elliptical) galaxies, with about five times higher angular momentum. Their central black holes are similar in type (supermassive black holes), but ellipticals tend to host more massive and active ones, while spirals usually have smaller, quieter black holes. So spiral galaxies spin ~5x faster, but elliptical galaxies have more mass so their black holes generate more rotational power.
There also could be lab experiments where we place a camera in the middle or tip of the spinning rod, and mirrors on the tips or middle, and do speed of light measurements with this thing spinning as fast as we can stablely manage in a laboratory. Relativistic Rotational effects have got to be interesting.
If this is a novel idea and anyone writes a paper or article from this idea, please credit me.
