It is kind of wild that we stumbled upon transmitting information via electromagnetic waves so early on. They seem to be hard to beat.
Fortunately for us we can see them.
Gravity waves are much harder to observe.
Re:Freeman Dyson: Gravitational Machines
by BurningFrog on Friday June 09, 2023 @03:26PM
(#36262844)
You can also argue that we can see them because they are stronger and are evolutionary important.
Well, I'd call the inner ear an evolutionary response to gravity...
Not unexpected; electromagnetism is 40 orders of magnitude stronger than gravity!
It makes sense that the easiest to implement would also be the easiest to learn. It's more shocking just how much harder every other option is.
What other options are there apart from mentioned gravity? I mean there are waves in materials like sound but that seem to be easier than EM.
Neutrinos, perhaps.
Ah, right, that's indeed high on the difficulty chart.
it doesn't seem surprising to me. people were in the lab playing with DC and AC and clearly heard "clicks" from remote instruments that correlated with them turning switches on and off.
I became curious about this and went to the book to learn more. The system proposed in the book is capable of radiating around 2.2 x 10^-29 W by rotating a bar weighing 500 tonnes about 270 times per minute.
[1] Source: Kraus, J. D. (1988). Antennas (2nd ed., p. 769). Retrieved from https://ia802907.us.archive.org/8/items/KrausAntennas19882ed...
It has been a few years, but I seem to recall that the transmitter was a 500T steel bar spun at very close to the maximum RPM the tensile strength of steel allowed; the radiated energy was something like a fraction of an attowatt. (An attowatt = 1*10^-18W)
There are more efficient transmitting schemes out there.