Say 1 KW. How does it scale?berkeman said:
To transmit any substantive power, you will need an efficient antenna, which means on the order of λ/4 to λ/2.bob012345 said:
I'm guessing signals would follow the water around the surface and interfere with Naval communications. Is that close? I'm interested in knowing or finding a mechanism to transmit a strong Lorentz force between objects at a significant distance. I think low frequency interactions would be easier to deal with. One application could be manipulating objects in low Earth orbit.berkeman said:
berkeman said:
As an illustration, the 16 kHz transmitter (callsign GBR) at Rugby, UK, now defunct, used a 1MW transmitter and achieved a radiated power of about 20kW. The antenna masts were 820 feet high and the area of the transmitting antenna was about a square mile.bob012345 said:
berkeman said:
tech99 said:
I know a guy (not me) who's obsessed with the idea of a magnetic launcher. I don't think his ideas of a long range magnetic 'beam' will work but it got me to thinking about a Lorentz force over a long distance between physical objects. In order to have a Lorentz force, you need fields and in order to get fields at a distance you need waves or beams in some form. So, I want a substantial field transmitted over a distance that can interact with a receiver of some type that is active, meaning it provides either a charged surface or current for the fields to interact with rather than just a passive detector. Sort of like using strong EM waves to accelerate charged particles in new compact accelerator designs but over a distance and acting on a larger object.berkeman said:
Thanks. Beamed propulsion is becoming quite a mainstream concept now in advanced propulsion circles and people discuss beams over planetary distances but they are very weak and require immense power which is why a Lorentz force based propulsion concept would be vastly superior. As for the Lorentz force alternating, yes, of course it does and that's exactly why I wanted a lower frequency source so the target currents or charges could match the phase of the field to keep the force in one direction.tech99 said:
berkeman said:
So you want to have a resonant antenna as the target to try to maximize the unidirectional force, it sounds like. Interesting idea, and it would be good to see the math. Remember that the physical size of an efficient antenna is on the order of a wavelength. Maybe you could work on the calcs for a large array of resonant antennas fixed to a sail-type structure to see what kind of drive you could get in space...bob012345 said:
Thanks. I'll try and get a little more mathematical basis for the idea on paper. Thanks for the suggestion.berkeman said:
Thanks. The original concept is an independent current source matching the known phase of the incoming wave. The refined idea is to allow the wave to energize a current, as usual, and then phase delay and orient that current to match and interact with the incoming magnetic field.Tom.G said:
It could be solar panels for example if one was talking about space applications in the inner solar system. I also suggested above the energy could ultimately come from the same source generating the wave in the first place. What are getting at?Tom.G said:
bob012345 said:
Thanks. I hope everyone realizes we are discussing a concept not a finished product or design. That said, hopefully, on the order as efficient as known low thrust propulsion techniques so about 1N force for 1kg mass and 1square meter area. But these are large unknowns that depend on what parameters of EM waves are used and how effectively they can be coupled to a material surface at a distance. I'm looking for a free decent EM simulator to play with the concept. Any recommendations?anorlunda said:
