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I Electric or magnetic field pulse generetor

  1. May 3, 2017 #1
    Hi,

    I would like to create an electric or magnetic pulses in an open ended cone, sphere or a tube. The pulse would have to be generated in such a way so that it is not actually connected with the container in any way (ie. it can't be a device in the center of the container which generates the pulse AND is also connected to it), and the pulse has to happen within the container. The pulses have to be as strong as possible. Additional constraint is that it has to be able to operate within vacuum or near vacuum. How would I go about this?
     
  2. jcsd
  3. May 4, 2017 #2

    tech99

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    You can use a coaxial cable feeding a probe, which might be a loop or dipole. Please tell us more about the power you are seeking and more about your experiment.
     
  4. May 4, 2017 #3
    Well, it is inspired by this: https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) except it wouldn't be done with nuclear bombs, but rather em pulses. Instead of having EM bombs detonating (bad idea), I'd like to go about this with some sort of a more or less internal electric/magnetic pulse so it not a hazard for surrounding tech/people. This is why whatever generates the pulse can't be physically connected to the cone (cone so that it limits energy waste ~ "coumbustion chamber"). I'm hoping if this can be done without expelling any devices so it would simplify the propulsion system. I'm hoping the forces generated this way would be sufficient to counter Earths gravitational field. Please don't laugh too much at this idea :)
     
  5. May 5, 2017 #4

    davenn

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    I suspect you don't understand what an EM signal is ..... do some study on EM waves ..... radio transmitters and the like

    then do some reading on light sails to see how difficult it is to use the EM output from the sun to move the sails and how big they have to be


    so what is it connected to ? ( Im assuming by cone you mean the capsule that the astronauts would be in ?)

    what devices are you referring to ?
    something has to be expelled else you don't get any thrust


    you are not likely to produce anything like this
    consider the megawatts generated and emitted by big radio transmitters .... nothing moves
    the force available for propulsion of an EM wave is tiny and requires huge amounts of energy to create that tiny force.

    current chemical/liquid oxygen and hydrogen etc types rocket propulsion are substantially more efficient
     
  6. May 5, 2017 #5
    I do know what EM is and I'm familiar with light sails, but that's not what I meant. Let me rephrase then, I want a pure magnetic detonation or pure electric pulse. As in for example, 10T magnetic pulse.


    It's not connected to anything, it can't be. The cone is not where the astronauts would be (why would anyone create magnetic or electric pulses in the same room with people?!), but a very rough equivalent of a combustion chamber (no, I don't expect magnetic or electric pulses to burn). Please check the link to wikipedia about the nuclear propulsion system. It's the same idea, except it would create magnetic and/or electric pulses (again, NOT laser, maser or any other beams). I think I was fairly clear on this. Also, I'm not discussing a complete rocket, this would be just the engine.

    Imagine if I had a rocket that has thousands of small bombs which when detonated cause, say, 1 kT magnetic pulse (yes, I know, that is quite a lot). This pulse would then interact with the rocket and cause it to move. What I wonder is if it's possible to do this without any bombs. For example, perhaps generate plasma in some sort of a magnetic or electrostatic confinement which would then cause a pulse upon some trigger (this is just an illustration, I'm not saying any and all plasma will cause a magnetic pulse or that this is even possible in any way). Let me be even more clear: I'd like to avoid having a system that detonates some sort of multi kT magnetic bombs on it's tail. I don't want to pay for all the fried electric equipment or endanger people:)


    I've addressed this before, but since you managed to completely misunderstand my post (because I used the word EM in an unclear and somewhat wrong manner, which is my fault) I'll repeat it again. This idea is not related to light sails or using some sort of a powerful laser, maser or any other em beam as a means of propulsion.


    Just to be clear, I'm not interested in a chemical propulsion system. I want a pure electric propulsion based on an interaction of electric and/or magnetic fields.
     
  7. May 5, 2017 #6

    Vanadium 50

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    I don't think you do. You're talking about getting impulses comparable to nuclear explosions using ordinary EM fields. This doesn't happen. We don't see cell towers destroying cities when they malfunction.
     
  8. May 5, 2017 #7
    I'm not talking about cell towers and ordinary EM fields as a means of propulsion. I don't know how to be more clear regarding this. You guys are fundamentally misunderstanding the idea and got hung on the cell tower concept that has nothing to do with it. This is NOT about some RF antenna, cell tower, beam, source of light, lightsail or something similar or anything that comes out of any kind, type, sort and whatnot antenna. Comparisons to cell towers, antenna, lightsails and similar means you are misunderstanding the idea. I'm NOT discussing that and it is NOT the same thing. This is not about having any antenna sending some EM beam.

    It's about creating a magnetic or electric pulse. If this confuses you, let's just go with purely magnetic pulse. Ie, what would happen if you had a block of iron that weighs 1 KG and suddenly for a 1 second a magnetic field of strength 1T appeared 1 mm away from it? It would move in the direction of the field. Is 1T field achievable? Yes it is. What I want to do is generate such pulses that would attract and/or repulse. I hope that's a lot more clear. If you have a need to say something like "but cell towers don't generate magnetic pulses" or "but iron is never repulsed by a magnetic field (i know it's not)" or invoke any cell tower, light sail, RF antenna related statement, idea or concept, you are misunderstanding what I'm saying.
     
    Last edited: May 6, 2017
  9. May 6, 2017 #8

    davenn

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    not going to give you any useable thrust for the same reason that I stated earlier

    you are really not making any sense

    it's not the magnetic pulse that is giving the thrust !!


    as I said earlier and V50 reiterated..... you have no idea


    PLEASE read up on what an electric or magnetic field is and how it is produced

    We know what they are and see all the problems with your comments. But unfortunately you don't have the understanding to realise your errors


    Dave
     
  10. May 6, 2017 #9
    What do you mean? Are you saying that a piece of iron in a magnetic field would experience no force acting upon it? If I get a magnet, a piece of iron and record a video where iron moves in the direction of the static magnet (or vice versa), will you start reasoning with me? So far the only thing you guys are trying to convince me is that a permanent magnet will never do anything to a piece of iron. Heck, according to you guys, if I managed to produce a field of 1 mega tesla it would do nothing to 1 gram of iron ... because cell towers don't level cities when they malfunction and light sails are not very efficient. Sorry for being facetious :(


    You do realize that the basic point of this question is exactly that, right? How to create a massive short lived electromagnetic field, except that I don't want to use solenoids? You do realize that a magnetic field of say 100T would force a piece of iron in its vicinity to move? Are you denying this? Do I have some abnormal magnets at home which attract iron (quite violently) and no other permanent magnet on the planet does this?

    Let me restate the idea again. An oversimplified version is that a vessel is an iron sphere in a vacuum with no friction (like every other physics experiment ). The engine creates an equivalent of a permanent magnet in front of it for a very short period of time. The interaction of the permanent magnet and the iron sphere causes them both to move. Then a new "magnet" is "created" a bit further away and the process repeats. Of course, in reality the permanent magnet wouldn't be created ex nihilo since that is impossible and not really the point (normally I wouldn't say that but here i guess i have to because you might accuse me of wanting to violate conservation of energy and create stuff from nothing), just the field would be produced that would interact with the engine and/or vessel. More generally the propulsion would work based on the interaction of magnetic and electric fields. Not antennae that you obsess so much about.


    From your feedback the only thing I got is that you completely misunderstood me. I've tried to restate it several times, but you just keep going with something I'm not discussing. I have a feeling you are not really reading anything I write. For example, I have no idea how someone managed to get the "astronouts would be in a cone" thing?! However, I'm willing to listen. What are my problems? What understanding am I missing? How do you think a permanent magnet of say 1 T interacts with a 1 gram of iron at the distance of 1 mm? Please don't say "nothing happens" and mention cell towers while claiming that a static bar magnet's magnetic field has nothing to do with iron sphere moving towards it.

    And yes, I do know that generating things like 100T magnetic fields is extraordinarily complex and expensive. It's not the point here.
     
    Last edited: May 6, 2017
  11. May 6, 2017 #10

    davenn

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    we have tried to explain to your that your idea wont work in the way you think it will, you wont listen
    so it is REALLY difficult to reason with someone with a closed mind to reality

    NONE of us have said that ....


    in opposite directions so that it will collide with the other side of the sphere that is inside of .... there is NO THRUST, no forward motion


    you are not telling us anything we don't already know


    of course there is an interaction, none of us have stated anything different

    I have given up ....... if you are not prepared to read up on some real physics ... what can we all do to help you ?

    have a read of this .....
    https://www.researchgate.net/publication/301248920_Generation_of_strong_pulsed_magnetic_fields_using_a_compact_short_pulse_generator [Broken]
    unfortunately the full paper is behind a paywall
    but good luck doing that outside a multi-million $$ lab
     
    Last edited by a moderator: May 8, 2017
  12. May 6, 2017 #11

    Drakkith

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    I'm sorry but you cannot create an electromagnetic field from a spacecraft which then moves the spacecraft that generated it. Not without interacting, in some fashion, with an external object. Otherwise it would be a violation of conservation of momentum (in that you have generated net momentum in one direction without also generating momentum in the opposite). Given that you probably won't be near to any large objects in space, something must be directed opposite the direction the spacecraft travels. That's got to be either radiation, in which we already have several plausible propulsion options such as lasers/masers, or matter, such as a standard rocket engine or an ion engine.
     
  13. May 6, 2017 #12

    Nugatory

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    And by Newton's third law there would be an equal and opposite force on whatever was generating the field, you don't get any net thrust out of the system. To get thrust, you have to send something out the back. You're working with electrical and magnetic fields, so that something is going to be electromagnetic radiation; one way or another, your drive is going to end up being some kind of antenna generating some kind of EM beam.
    You've mentioned magnetic and electric pulses several times. There's no such thing, only electromagnetic pulses. You can't have a sudden change (which is what a pulse is) in the electrical field without a corresponding change in the magnetic field, and vice versa. And an electromagnetic pulse is EM radiation, which is why everyone reading this thread is thinking on terms of EM radiation.
     
  14. May 6, 2017 #13

    Nidum

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    This is just another version of the man pulling himself up by his bootstraps concept .
     
  15. May 6, 2017 #14
    No you heaven't. You explained that something I never said or proposed wouldn't work, and I agree with you. You are absolutely correct, it's just that what your are refuting has nothing to do with my idea. You guys are literally pulling off a straw man argument after I said several times you got it wrong and now it's also ad hominem. I'm not closed to reality, I'm just struggling here to correctly translate my idea to you.

    I never said it's inside the sphere, it's outside of it. See? You are not really reading what I write. A permanent magnet is outside of the sphere (i stated this very clearly). And it does generate thrust. Every time you have a need to mention cell towers and antenna, keep in mind my idea is very roughly about an EXTERNAL, disconnected magnet.

    It's not behind a paywall, but you do have a reading and comprehension problem. Anyway, thank you, I appreciate the article.


    OK, this is useful and way more in line with the proposed idea. I get this part with the conservation of momentum and I have to admit I hope(d) there might be some way to avoid this law, but it's unlikely there is some trick. Basically I'd be stuck with a very large gauss gun where I'd have to have a "bullet" which would be internally accelerated to some high velocity and then also detonate. That's not very elegant or safe :(


    This is not really a problem, I'm just looking for the easiest way of what that something is. It was never my idea that this field appears magically out of the thin air. General idea is to have some sort of an electric drive that generates a useful force, unlike what ion engines can do. Sure, chemical stuff does way better, but I'm not interested in that.

    Sure, in the same sense that a solenoid inside a generator is an antenna, but unless it caused gamma ray bursts it would probably not be much of a problem.

    True, but everyone else here interpreted my words with cell tower EM and this is NOT what I meant. It's more in line with bar magnet and iron interaction. I really don't know how to make this clear to some people here. I do know that it's just electromagnetic field and the mentioned corresponding changes (basically LC circuit interaction), but practically there is some difference in having a van de graaf generator and a bar magnet.


    It's not. I literally mentioned this several times, including in the original post where i mentioned for this reason specifically that the pulse generating device can't be connected to the cone. Brush up on your reading skills before quick judgments.
     
    Last edited: May 6, 2017
  16. May 6, 2017 #15

    davenn

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    so if it is disconnected there is still no thrust as I stated ... it will move in the opposite direction
    I have never mentioned cell towers .... you are the one doing that ..... give it up !!

    you CANNOT avoid physical laws ..... give it up !!
     
  17. May 6, 2017 #16

    davenn

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    brush up on your physics before making totally incorrect statements
     
  18. May 6, 2017 #17

    Drakkith

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    I think that's enough for this thread. It's a bit too heated to generate any more useful discussion. Archon, whatever device you envision, it MUST obey all conservation (and other appropriate) laws. There's simply no way to get around it.

    Thread closed.
     
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