Every day gravity is Newtonian, and gets more interesting at higher sampling rates

Sensitive three axis gravimeters show that vector sun moon tidal signals are nearly perfectly Newtonian, only requiring three linear regressions (6 numbers) to lock a station to the sun and moon for position and orientation sensing. Many types now.

This is one month for the vertical component of the vectors signal. it is Newtonian GM/r^2 of the sun at the station minus the sun acting at the center of the earth, plus the moon acting at the station minus the moon on the center of the earth. Plus the centrifugal acceleration due to the earth’s rotation. Using JPL Horizon’s you can get the vector position data online, do the fairly simple calculations and the linear regressions. For longer times you can add earth moon barycenter rotation, but it is easier to just run continuous calibrations every hour. For MEMS and other types of low cost gravimeters, they will drift, but with hourly and daily and weekly calibrations only requiring a bit of code, easy to just do it. This data is one sample per minute. At Ksps, Msps, Gsps (samples per second) you can start to use time of flight to localize the source of the gravity. The gravitational potential changes diffuse, then you calculate and measure the local gradients with these simple devices.

At sampling rates higher then 1 Msps, it is possible to resolve location on the earth and sun. Then you have to use passive time of flight correlation imaging and other methods to sort out and image the sources.

I hope more people will try this. Especially groups designing atomic clock chips, atom interferometer sensors, atomic force position monitoring, Bose Einstein gravimeters, electrochemical gravimeters, and simply more sensitive seismometers, accelerometers and vibration sensors capable of picking up the sun moon tidal signal (it is a huge signal in gravity terms). Do that, lock to the sun and moon, then work with the residual and time of flight correlation to image the atmosphere, and other things. Somewhere in there you can routinely measure the speed of gravity and use that to lock your devices to local, regional, global, heliospheric, galactic and larger models.

Richard K Collins

About: Richard K Collins

Director, The Internet Foundation Studying formation and optimized collaboration of global communities. Applying the Internet to solve global problems and build sustainable communities. Internet policies, standards and best practices.

2 thoughts on “Every day gravity is Newtonian, and gets more interesting at higher sampling rates”

  1. I was looking into cheap ways to make DIY gravimeter’s and stumbled across your youtube channel. And a few years later, this blog, and so on.

    Was wondering if you can clean up this post, and elaborate on all matters. I can’t seem to grasp it all very well, because the language / structuring of sentences is not very straight forward. I like how you have broad interests, but it would serve you to put all your thoughts about gravimeters in one place, and slowly expand there.

    1. I have been working about 18 hours a day, 7 days a week for most of the last 25 years of the Internet Foundation. Just now I worked from 6 am to midnight yeaterday, slept an hour and now working at 1 am. There are many things I would like to do.
      A zero force spring can be made with sensitive amplifiers and Analog to Digital Converters (ADCs) with fast sampling rates. Take the Fourier transform and look at the low frequencies or simply run FFTs many times a second and use the slowly varying parts. Software Defined Radios are improving in bit depth and sampling rate. All detectors and methods still require getting your hands dirty with data and data storage and computing. You can use “null methods” and keep a pendulum or mass still, using the control signals for follow the forces it faces.

Leave a Reply

Your email address will not be published. Required fields are marked *