# Note in Houston Astronomical Society about Gravitational Engineering

I have been looking at all the radio astronomy groups on the Internet. There are a lot of them, at all levels of age and experience and size. I am trying to see how many of the ground and orbiting networks are also picking up signals in the nanoHertz to GHz range.

That includes variations of signals whose central frequency can be anything. A red laser at 635 to 660 nanometer (nm) covers frequencies from 472.11 TeraHertz (THz) to 454.23 THz. A photodiode with amplifiers and fast ADCs (analog to digital converter) can allow monitoring the variations from that central frequency for a bandwidth up to a GHz wide or more. 472.11 TeraHertz is 0.47211 PetaHertz.

A 1.03 MHz AM radio stations playing music – the signal received can be thought of as a 1.03 MHz carrier with KiloHertz signal. Or it can be thought of as a KHz carrier and MHz modulation. Both can be displayed and monitored and used where you have software defined radio tools. The bandwidth of the SDRs at the low end is about 3 Msps (Mega Samples Per Second) and they have analog mixers and detectors to extract those variations for signals from 1 Hz up to 100 GHz. The range expands every day. If someone is using a laser link for communication through air or fiber then people are using frequencies into the PetaHertz range. If you had a signal at 1 nanoMeter it would have a have a frequency of 2.99792458E8/1E-9 = 2.99792458E17 Hertz or 299.792458 PetaHertz. It would have an energy of 1239.841984 electron Volts – a soft xray. You might use that in space for transmitting power. Or in a vacuum channel or microvacuum channel.

I have been tracking these kinds of things for about 50 years now. I am just writing them here because it asked me what was on my mind. And what I am thinking about a lot for the last couple of decades is how to measure the inside of the earth and the inside of the sun with gravitational signals. That is what I worked on and what I studied in schools. But in August 2017 there was a collision of two neutron stars. The gravitational wave observatories picked it up and it also registered on a number of electromagnetic sensors. In a quiet note, it showed that the speed of light and the speed of gravity are identical. Not just close, but identical. And that, since I had used and studied the gravitational potential most of my life, and had measured the speed of gravity, that they must share the same underlying potential. The same underlying processes.

I say that with good feelings and bad ones. Because it looks like “gravity” is just an aspect of electromagnetism. Or, more hopeful, that anyone who has worked with electromagnetism can apply most everything they know to work in new fields of “gravitational engineering”, “gravitational communication”, “gravitational modeling”, “gravitational imaging”.

The bad feelings some because it means that gravity also is refracted, reflected, absorbed, emitted, can be modulated and can be used in really really complicated devices – and it means I have to learn a lot of new things. I am getting older and opening up new industries, and applications for gravitational technologies is not easy.

When I was studying astrophysics, aerodynamics, partial differential equations and gravitational engineering (they did not call it that), I met Joe Weber. He invented the Weber bar that was the earliest attempt to measure gravitational waves. His student, Robert Forward, wrote a dissertation “Detectors for Dynamic Gravitational Fields” in 1965 (I studied at UMD from 1975-1979). He talks about merging gravitation and electromagnetic technologies. And indicated that it can only be done at a social level by changing the units and dimensions of equations and tools that people use. We call a lot of things “gravitational” and other things “electromagnetic” because the groups were separate. That is merging now. And for all practical purposes you can study “gravitational engineering” and not be laughed at or vilified.

What I am trying to do now is find all the people working in either gravity or electromagnetism or acoustics or any field where they are (or could be) picking up variations in the earth electromagnetic-gravitational field in those frequencies from nanoHertz to GigaHertz particularly. And, as I indicated above, that means following the wide bandwidth (Msps and Gsps) variations in power level for signal at any center frequency.

That affects optical and infrared astronomers (or any other parts of the spectrum) because if you just track the variations of a single star in one wavelength (red, or blue or 1.420,405,751 GigaHertz) its local variations, the variations through space, the variations through the atmosphere (unless you are already in space) and to the detectors can be spread out and investigated in great detail.

So I want to ask anyone who has a small telescope and is using ZWO cameras to consider picking a bright star and then set the region of interest to those few pixels you can track at maximum frame rate and maximum gain. Record it in raw format. If you use SharpCap that can be SER format, and SharpCap let you select region of interest. It also lets you set the gain over a wide range.

If two or more people, even next to each other, with different telescope and different cameras – ultimately they will see nearly the identical source. And that means all the variations can give information about the cameras, electronics, processing, temperature and environment of each camera. For separated cameras it means information about the specific pathways through the atmosphere and eventually that should get to the atmospheric modeling groups and the meteorological networks.

Facebook has no good way to help people to share information beyond chats and a few photos and links. I I think you an append a PNG, maybe a GIF, not SER. Not any of the common lossless format. As Director of the Internet Foundation I hope one day to get Facebook, YouTube and all the “social” media sites to also allow serious communication and collaboration. It is not hard. YouTube knows how to use lossless formats and could improve them. But they started as crazy videos and seem to want to stay that way. Even though tens of millions are trying to use that site for serious efforts. A little accommodation would go a long way for global education, scientific collaboration, global issues and just people working on small things where their only community is spread over the whole world.

It asked me what is on my mind. These are a few of the things that are connected when I am thinking about the specific people in HAS, the people in Houston area and Texas who never get to see the sky, global communities of astronomers and people using cameras. In my tiny world, every topic – followed completely – ultimately includes all things on the Internet, all humans, and all sensors and computers gathering and processing information about the universe.

Richard Collins, Director, The Internet Foundation