Extended Data Fig. 3: Measurement of the gravitational drive force.
From: Experimental constraints on the symmetron field with a magnetically levitated force sensor
a. The PSD of the force sensor’s motion, with the tungsten disk at rest, is shown by the blue line labeled “thermal noise”. Each measurement has a duration of 1000 s, and the results are averaged over 10 runs. The noise baseline, averaging 1.06 × 10−6 V2/Hz, is represented by the blue dashed line. The area under the peak, highlighted by the blue-shaded region, is obtained by integrating the PSD within the 15.35 to 15.36 Hz frequency range. b. The PSD of the force sensor’s motion, with the tungsten disk rotating above the force sensor, is depicted by the red line labeled as “Gravity drive". The noise baseline, averaging 1.24 × 10−6 V2/Hz, is represented by the red dashed line. The area under the peak, represented by the red-shaded region, is also obtained by integrating the PSD within the 15.35 to 15.36 Hz frequency range. c. Photograph of the tungsten source mass disk used in the Newtonian gravity measurement. d. The red point represents the average measured force, calculated from the 10 results shown in panels a and b, with error bars indicating the standard deviation. The grey band with grid lines represents the theoretical Newtonian gravity value, with uncertainty arising from geometric errors.
