reactor1967 Posted August 17, 2008 Share Posted August 17, 2008 ++++++++++++++++++++++++ ************************ ************************ Electromagnet ************************ ************************ ++++++++++++++++++++++++ (((((*%%%%%%%*)))))))))) (((((*%%%%%%%*)))))))))) ((((((*%%%%%*))))))))))) Non-magnetic spring. Is not affected by the magnet (((((((*%%%*)))))))))))) ((((((((*%%*)))))))))))) (((##########)))))))) metal can be pulled by magnet (((((((((*%*)))))))))))) ((((((((((^))))))))))))) ((((((((((|))))))))))))) Momentum toward the electromagnet when powered up. This is a electromagnet with a spring attached at the bottom that is made of a material which is not affected by the magnetism. At the bottom of the spring is a piece of metal which is affected by the magnetism. In theory the electromagnet should pull the piece of metal toward it causing the spring to push up against the magnetic without a opposing force thus creating momentum in the upwards direction which can be designed to be used as a propulsion system. Can anyone find a flaw with this? The ( and % are spaces. Its very hard to post anything here unless it is a link to something. Its a diagram showing my concept. Link to comment Share on other sites More sharing options...
RainmanTime Posted August 18, 2008 Share Posted August 18, 2008 Can anyone find a flaw with this? Several. Most of the problems likely stem from assumptions you have made that you have not stated. So let me question you about some things, to see if you would be willing to state what you thought going into your analysis.1) Are you assuming that the momentum is due to the mass of the piece of metal times its velocity towards the magnet? 2) If so, did you assume this momentum remains constant from the time you turn on the magnet? 3) Are you aware that a spring is an energy storage device? Do you know what a "spring constant" tells us about a spring's ability to store energy? 4) If so, what happens to that stored energy when you turn off the magnet? 5) What is the magnet attached to (if anything)? ( a truss that is connected to the ground?) 6) If not affixed to a truss that is attached to the ground, what would stop the magnet from moving upwards as the spring gets compressed? 7) What sort of electrical signal is driving the eletcromagnet? DC or AC? 8) Can you draw a proper free-body diagram of all the forces involved (including the transient ones) and use F=ma along with several other equations of physics to program a simulation to tell you what should happen? 9) Do you know that it is not momentum that creates a propulsive force, but rather the rate of change of momentum that results in such a force? (This is how jet engines create thrust). 10) Can you understand that while the initial rate of change of momentum will be positive (the metal accelerates towards the magnet) that eventually the rate of change of momentum of the metal will become negative? RMT Link to comment Share on other sites More sharing options...
RainmanTime Posted August 18, 2008 Share Posted August 18, 2008 The ( and % are spaces. Its very hard to post anything here unless it is a link to something. Its a diagram showing my concept. I can definitely help you with this. Do you have a drawing program of any sort? (The answer to this is "yes" if you have any Windows OS, since MS Paint is a drawing program) You can draw anything in a program like this (or a more engineering-oriented program like MS Visio, or AutoCAD, or even MS Powerpoint) and then save the image as a .GIF or .JPG file. Once you have such a file, you can create a (free) account at a website like "imageshack.com" or "photobucket.com" where you can upload the .GIF or .JPG file and include the URL for that image inside the "IMG" tags in your posts. Here is an example of what the code looks like, just replacing the normal HTML brackets ("[") with curly brackets ("{"):{IMG}http://i124.photobucket.com/albums/p32/RainmanTime/Sysmodel.gif{/IMG} Embedding this code in this post but with the proper brackets results in the image stored at photobucket.com to be displayed here. Like this: Hope that helps... RMT Link to comment Share on other sites More sharing options...
Kanigo2 Posted August 18, 2008 Share Posted August 18, 2008 I was just going to say there was no source of energy RMT but whatever gets you going... Link to comment Share on other sites More sharing options...
TimeLord Posted August 18, 2008 Share Posted August 18, 2008 The electromagnet & piece of metal will experience an equal & opposite force. The system will contract/expand, but there will be no net linear force. Link to comment Share on other sites More sharing options...
ruthless Posted August 18, 2008 Share Posted August 18, 2008 what if the magnets were angled though? would it have linear force then? Link to comment Share on other sites More sharing options...
RainmanTime Posted August 18, 2008 Share Posted August 18, 2008 good to see you back ruthless: what if the magnets were angled though? How do you mean? Could you draw and post a diagram? would it have linear force then? It is not that there are no linear forces in reactor's setup. In fact, an electromagnet actually creates a magnetic attractive force between itself and the metal plate when it is first turned on. However, for many reasons (one being the physical nature of a spring to store energy) the forces do not remain constant in magnitude or direction. This is, in point of fact, one of the things that makes engineering "hard". Being able to recognize what is a "statics problem" (where all forces remain constant and nothing is moving relative to some fixed reference) which is a fairly easy problem to solve, and what are the more difficult-to-solve "dynamics problem". Whether a statics or dynamics problem, solving either type of problem relies most heavily on drawing a proper free body diagram, and labeling ALL the forces that currently act and/or will act on the bodies involved.This is the first and most important lesson that engineers are taught in how to solve static and dynamic physical problems: Step 1 - Draw a Free Body Diagram! RMT Link to comment Share on other sites More sharing options...
ruthless Posted August 18, 2008 Share Posted August 18, 2008 "good to see you back ruthless:" thanks, good to be back. been pretty bored without tti lol. "How do you mean? Could you draw and post a diagram?" no i cant, but i can try my best to explain it. when two magnets are perfectly flat and placed on top of each other and they are facing positive positive, or negative negative, they push away. if you slightly angle one, it will move in the direction it is angled. so if you were to make a magnetic road and then put magnets on the bottom of a car with some kind of device that angled the magnets on the bottom of the car in different directions, would it be able to be driven similar to a car? i'll try to dust off the 'ol scanner tomorrow and see if i can whip something up. Link to comment Share on other sites More sharing options...
ruthless Posted August 18, 2008 Share Posted August 18, 2008 ive actually been thinking about this idea since i was very young. i even built a few models when i was younger. my idea was a little different though. i wanted to use earth magnets like neodymium or strontium. it would be clean, free energy. would that rock or what? Link to comment Share on other sites More sharing options...
reactor1967 Posted August 18, 2008 Author Share Posted August 18, 2008 Several. Most of the problems likely stem from assumptions you have made that you have not stated. So let me question you about some things, to see if you would be willing to state what you thought going into your analysis. 1) Are you assuming that the momentum is due to the mass of the piece of metal times its velocity towards the magnet? 2) If so, did you assume this momentum remains constant from the time you turn on the magnet? 3) Are you aware that a spring is an energy storage device? Do you know what a "spring constant" tells us about a spring's ability to store energy? 4) If so, what happens to that stored energy when you turn off the magnet? 5) What is the magnet attached to (if anything)? ( a truss that is connected to the ground?) 6) If not affixed to a truss that is attached to the ground, what would stop the magnet from moving upwards as the spring gets compressed? 7) What sort of electrical signal is driving the eletcromagnet? DC or AC? 8) Can you draw a proper free-body diagram of all the forces involved (including the transient ones) and use F=ma along with several other equations of physics to program a simulation to tell you what should happen? 9) Do you know that it is not momentum that creates a propulsive force, but rather the rate of change of momentum that results in such a force? (This is how jet engines create thrust). 10) Can you understand that while the initial rate of change of momentum will be positive (the metal accelerates towards the magnet) that eventually the rate of change of momentum of the metal will become negative? RMT Recursion. Closed-loops. Orobouros. RMT:You have clearly showed that there is a lot I have not considered. 1. On momentum I was meaning the energy that the spring stored after it overcame the weight of the electromagnet and was released into forward movement of the of electromagnet, spring, and metal together. 2. I did not assume the momentum would remain constant because I new things would change with this setup as the metal and spring moved. 3. Yes I was aware about a spring as a energy storage device. But I did not know what a "spring constant" tells me about a springs ability to store energy? I am not familiar with that. 4. When I turn off the magnet the energy in the spring could be released in the other direction but I was wondering if the magnetic could release that energy slowly enough not to affect all of the forward momentum. Forward momentum - backwards momentum if the forward was greater than the backward momentum then the forward momentum would not cancel out completely. But, on the flip side as the electro-magnet moved depending on the magnetic field the springs energy could also be released. What do you think about this setup leaving enough energy so that the electro-magnet still moves forward? 5. The electro-magnetic would not be attached to anything except the spring but the metal would be attached to the spring somehow and the spring would be attached to the electro-magnet. 6. What would stop the magnetic from moving as the spring compressed? I hope nothing would stop it that was my point. I wanted to make the electro-magnet move and keep moving. 7. The electrical signal would be DC. But, now that I think about it AC might work too because the metal would still be attracted by either pole. AC at some frequency might be better. Well problem is the spring would have to release at less energy than it released when it was compressed. What do you think about this? 8. On drawing the forces I would need to work with that. I am not use to drawing forces and I probably have a lot to learn in that area. If I was going to pursue this further drawing the forces would probably be the next thing I would want to do or learn how to do. 9. No, I did not know that it was the rate of change that creates force. I always thought of it as a constant. I guess I was wrong. 10. Yes I can understand the rate of change of the metal will be negative. I did not understand this before I read your post. Thank you. Reactor Link to comment Share on other sites More sharing options...
reactor1967 Posted August 18, 2008 Author Share Posted August 18, 2008 Thank you. I did not know about those web sights I will take a look at them and start doing that. While we are on the subject I have a question. When I post I see this at the bottom "You may attach a file while editing. How does that work? Link to comment Share on other sites More sharing options...
RainmanTime Posted August 18, 2008 Share Posted August 18, 2008 Reactor, Glad you got the hang of the drawing and image posting here so quickly. I am also glad that you are rapidly seeing the engineering issues with your idea. I am not trying to insult you, only get you to consider things that will move you along in understanding. 5. The electro-magnetic would not be attached to anything except the spring but the metal would be attached to the spring somehow and the spring would be attached to the electro-magnet. I could go thru all your answers, but as I say above these were meant to get you thinking about things you may have (implicity or explicity) assumed at the outset of your idea. This answer cuts to the chase, which is what I wish to do. So let me assume the magnet sits in a "cradle" of sorts which holds it above the ground, but to which it is not attached/affixed in any way. Now imagine that I can actively control the speed at which the metal plate approaches the magnet and compresses the spring. (In reality I could certainly do this by controlling the expansion and contraction of the magnetic field, but that is more advanced than I need you to think right now)Imagine I have two distinct speeds that I can command the metal plate to approach the magnet when it is turned on: REALLY slow and REALLY fast. In the REALLY slow case the spring is just going to compress and the magnet will not move at all (if it is heavy enough). There will be a point of equilibrium where the tension in the spring balances the maximum magnetic forces emitted by the magnet. So you would see the metal plate move up a bit and then stop. In the REALLY fast case the acceleration of the plate against the spring would "pop" the magnet in the upwards direction for a moment and then the magnet would fall into a rest state similar to the really slow case (unless the acceleration was so great it popped the magnet out of its cradle). This imagination process helps demonstrate why it is the TIME RATE OF CHANGE OF MOMENTUM (in calculus this is symbolically expressed as d(mV)/dt) that impacts the motion of an object. Quite literally, this is proof that Newton's Second Law is correct. But now let me REALLY cut to the chase and save you having to think about problems that other people already thought out, made mistakes, and have progressed beyond. I can fully see the idea behind what you are trying to do with this setup, and you may not even realize this is where you are going with it (expressed in these words): You are trying to extract energy from the universe by actively coupling with all the rest of the matter in the universe. If you don't understand that, it is OK... but you might need to trust me that this is the bottom line of what your idea is trying to do. It is called the Mach Effect. Now let me point you to a guy who is not only an engineer but also teaches physics at Cal State University, Fullerton... which is right down the highway from where I teach at Cal Poly, Pomona. His name is Dr. James Woodward and he has been working on experimental versions of what he calls the Mach-Lorentz Thruster (MLT). (NOTE to the wiki that follows: Dr. Woodward does NOT like calling it the Woodward Effect. He attributes all the knowledge behind it to Mach's Principle as aided by Lorentz). http://en.wikipedia.org/wiki/Woodward_effect The Mach Effect is strongly linked to Mach's principle, the concept that all momentum is linked to the mass of the rest of the universe, as well as the general theory of relativity. I am pointing you to his work because you can save a lot of time (not having to reinvent the wheel, not having to make the same mistakes he made, leverage his explanation of the effect, etc.) by following his work. If there is any merit to the idea, he and his team will be the first to quantify it because he is doing things in a REAL lab and he has derived real equations that predict the effect he is trying to test for. So far, the results have been disappointing and nothing has shown any previous knowledge of physics to be grossly in error.I also offer this because, if you read up on what he is doing, you will likely learn a lot more about engineering analysis and how what may seem obvious to you may have problems that you never considered. RMT Link to comment Share on other sites More sharing options...
RainmanTime Posted August 18, 2008 Share Posted August 18, 2008 While we are on the subject I have a question. When I post I see this at the bottom "You may attach a file while editing. How does that work? I do not know, because when I am writing a reply I do not see any such message as this. If you can help me find exactly where it says this I might be able to help. But as for now..sorry!RMT Link to comment Share on other sites More sharing options...
RainmanTime Posted August 18, 2008 Share Posted August 18, 2008 Deleted naughty boy tirade. I don't mean to be insulting, but that is not a DC signal. Assuming the y-axis is voltage, then as the voltage changes, so does the current, and that would make this an AC signal. Technically, this would be a shaped sawtooth AC signal with the shaping on the downside of each sawtooth caused by an R-L effect (most likely, but I am not positive).RMT Link to comment Share on other sites More sharing options...
Kanigo2 Posted August 18, 2008 Share Posted August 18, 2008 That is actually what the signal looks like RMT. The line is actually 0 voltage. the ramp up is actually the inductive resistance and the drop signal would be the power side. All he is showing is that he is turning it on and off at a set voltage and a certain frequency. For it to be an AC signal the voltage would actually have to phase to below the line. Link to comment Share on other sites More sharing options...
RainmanTime Posted August 18, 2008 Share Posted August 18, 2008 That is actually what the signal looks like RMT. The line is actually 0 voltage. the ramp up is actually the inductive resistance and the drop signal would be the power side. All he is showing is that he is turning it on and off at a set voltage and a certain frequency. So then it is neither AC nor DC (strictly speaking), but rather more what we call Pulse Width Modulation (PWM) with a long decay time constant. For it to be an AC signal the voltage would actually have to phase to below the line. Not always. DC bias could still make for an alternating waveform without any zero crossings. Yes?Sorry, I just love technical nitpicks...keeps one sharp! RMT Link to comment Share on other sites More sharing options...
RainmanTime Posted August 18, 2008 Share Posted August 18, 2008 no i cant, but i can try my best to explain it. when two magnets are perfectly flat and placed on top of each other and they are facing positive positive, or negative negative, they push away. if you slightly angle one, it will move in the direction it is angled. so if you were to make a magnetic road and then put magnets on the bottom of a car with some kind of device that angled the magnets on the bottom of the car in different directions, would it be able to be driven similar to a car? Well, you should be happy to know that, in a crude way, this is kind of the basis for MagLev trains! Although they do not have to angle the magnets to get forward motion. This is all handled by the flow of current through the magnets. The rate of change of current is directly proportional to the velocity induced between the two charged objects (the electromagnet and the tracks).Not too practical for roads; however, because we would have to change the entire road surface infrastructure to support it. RMT Link to comment Share on other sites More sharing options...
ruthless Posted August 18, 2008 Share Posted August 18, 2008 "Not too practical for roads; however, because we would have to change the entire road surface infrastructure to support it." we repave roads every few years anyways, so why not? repave a road every few years? or pave it once and never look back? sounds purdy practical to me. now i will admit its not the super moneymaker that corporations want, but it would make quite a few people happy. to me, it would be worth throwing away every car ever made, and i love cars. theres just too many positives and no negatives. i know this will exist one day, but i wonder if i will still be alive to see it. Link to comment Share on other sites More sharing options...
RainmanTime Posted August 18, 2008 Share Posted August 18, 2008 we repave roads every few years anyways, so why not? repave a road every few years? or pave it once and never look back? sounds purdy practical to me. Nope. It is way WAY more complex than simply repaving. It is nothing short of turning roadways (all of them, in order to support such a vehicle) into a complex network conduit with LOTS more parts and power flowing through them, etc. Indeed, paving would be right out! In place of paving you would have to have metal sheets that would act to conduct electricity over the entire road surface. Then, of course, the electricity has to come from somewhere...so you would need transformers and rectifier components to now be part of the road. Huge, huge, massive rework that would costs oodles of dollars. With minimal buyback simply because it would not be the "flying car" that most people envision as the next big step to free us from the roads and solve traffic problems. And if the corporations cannot make money building them, then as Adam Smith taught us: No one will build them.It is one of those engineering things. Once you take all the things into account that would have to change, you start to see just how cost prohibitive it would be. I know you don't like to hear that, but that is why MagLevs will always only be confined to "railroad track" kind of setups, rather than general roads that go everywhere. RMT Link to comment Share on other sites More sharing options...
ruthless Posted August 19, 2008 Share Posted August 19, 2008 "In place of paving you would have to have metal sheets that would act to conduct electricity over the entire road surface." no you wouldnt, you'd have earth magnet roads. neodymium, strontium, etc. "And if the corporations cannot make money building them, then as Adam Smith taught us: No one will build them." thats true, but in the future, when folks cant breathe from smog, folks wont care so much about money then. its not a moneymaking idea for sure, but it is one of the best available options that we dont use. tells alot about the world and its leaders. " I know you don't like to hear that, but that is why MagLevs will always only be confined to "railroad track" kind of setups, rather than general roads that go everywhere." we shall see if that holds up in the future. i'd bet just about every person in the world would want to buy one of these cars, thats an awful lot of money... especially when they hear of the safety benefits. when you'd grab that emergency brake, itd really stop. Link to comment Share on other sites More sharing options...
reactor1967 Posted August 19, 2008 Author Share Posted August 19, 2008 RMT: Thanks for your input. I will take a look at his work. On the DC I ment for that to be a DC signal. I will admit I could of drawn it to look more like a real oscilloscope with a point of reference and a time reference. Link to comment Share on other sites More sharing options...
RainmanTime Posted August 19, 2008 Share Posted August 19, 2008 no you wouldnt, you'd have earth magnet roads. neodymium, strontium, etc. Well, yeah, you could do it that way. But in doing so you have made the road extremely expensive. I mean gold-paved might be cheaper! But the bigger issue is whether there would be enough neodymium or strontium on earth to pave even all the roads in the US. These are the practical issues that scientists usually do not spend time thinking about, but engineers do because it is not just about "yes, we can do it" but "is it economically feasible to do it?" thats true, but in the future, when folks cant breathe from smog Expensive MagLev schemes are not the only way to fix the smog problem. Look at Los Angeles. When I first came here in the early 80s the smog was awful. Laws were passed that put California at the forefront of reducing auto emissions. Now all the smog controls that come on a car sold in any US state are standard. They used to be required only in CA. The air in LA is MUCH MUCH better these days! VERY few "stage 3 smog alerts" in any summer, which was not the case in the 80s. Also, did I tell you about my primary commute vehicle? It is a Honda Civic GX. The "G" stands for "Gas" as in "Natural Gas". It is actually the cleanest vehicle on the road...the exhuast from it is literally cleaner than the SoCal air it ingests!! Not to mention that I pay the equivalent of about $1.40 per gallon!! TWO benefits! but it is one of the best available options that we dont use Can you back that up with evidence and analysis? Because clearly it is not since I just mentioned an option (the Honda GX) which does not require any modification to the roadways. How is your effort going to get into school, ruthless? Once you start loading-up on the engineering courses you will also have to take a course or two in engineering economics. That is what will help you evaluate, just because you CAN do something, whether or not it makes financial sense to do it full-scale. For example: We COULD build a single-stage-to-orbit launch vehicle. It is technically possible. But the cost as compared to a staged vehicle (like the shuttle or the Delta and Atlas rockets) would be enormous. Hence why you do not see anyone trying to do it...they would not have customers because the customer would rather pay less for a staged vehicle to get their payload into space. i'd bet just about every person in the world would want to buy one of these cars, thats an awful lot of money... True, but it depends upon how much it would cost, and if enough people would want to buy it such that a company would take the risk and be able to make a profit. If a company cannot make a profit (or at least break even and pay their employees) there is no incentive to take the risk and do the work. especially when they hear of the safety benefits. when you'd grab that emergency brake, itd really stop. True, that is one of the points in favor of this idea. But you would still have to show a "Return On Investment" (ROI). It is the only way an engineering project can get green-lighted because nobody is going to throw their money down a hole unless at least a meager profit can be made.RMT Link to comment Share on other sites More sharing options...
ruthless Posted August 19, 2008 Share Posted August 19, 2008 "Well, yeah, you could do it that way. But in doing so you have made the road extremely expensive." not true. the way we are doing things now is much more expensive. much much more. magnets are pretty cheap actually. especially strontium. people nowadays have to pay taxes for roads and road maintenence, so things would be no different. the money to build the roads would come from the same place it always has. "But the bigger issue is whether there would be enough neodymium or strontium on earth to pave even all the roads in the US." the cool thing about that is, any magnetic material can be used to build the roads. theres more than plenty magnetic material around to repave every road in the world. "Expensive MagLev schemes are not the only way to fix the smog problem." nope, not the only way, but sure is the best way in my opinion. "It is actually the cleanest vehicle on the road...the exhuast from it is literally cleaner than the SoCal air it ingests!! Not to mention that I pay the equivalent of about $1.40 per gallon!! " heh. imagine a car that costs $0.00 per gallon, has no emissions, and never needs a tuneup. $1.40 per gallon is nice and all, but no matter the cost of the vehicle, it will eventually pay for itself, much like the solar panels on your home. "Can you back that up with evidence and analysis?" yes i can. would you like me to bombard several links? so your suggestion is once we use up all the oil, lets use up all the natural gas? what then? people will be forced to decide on an alternative. alternatives that have the lowest maintenence cost will then win. "How is your effort going to get into school, ruthless?" ill be moving onto the msu campus soon. "Once you start loading-up on the engineering courses you will also have to take a course or two in engineering economics. That is what will help you evaluate, just because you CAN do something, whether or not it makes financial sense to do it full-scale." heh. i wonder what they are teaching folks in economics classes! all economics boil down to is risk vs reward. in this case its risk its my opinion that you need to take a refresher course. " would be enormous. Hence why you do not see anyone trying to do it...they would not have customers because the customer would rather pay less for a staged vehicle to get their payload into space." thanks, you just proved my point. people always want what costs less. people want healthier things. and people really, really want to drive around and never feel a pothole again, not to mention being able to hover around. this is a consumers dream, and if done right, can make a huge profit. instead of wasting money on gas every day, they would instead buy new cars every year or two. "True, that is one of the points in favor of this idea. But you would still have to show a "Return On Investment" (ROI). It is the only way an engineering project can get green-lighted because nobody is going to throw their money down a hole unless at least a meager profit can be made." i can see the money able to be made from this. i can see the health benifits from this. i can see the safety benefits from this. i can see the comfort benefits from this. most importantly, i can see how the world could change from greed to care with a single idea. can you? ill leave you with this thought. when i first held an ipod nano in my hand, i looked at it and realized all that was involved in making it and it made me feel like the future was now. the technology was amazing, yet simple. its amazing how many people have one now. 10 years ago, there were none. now theres something to ponder on. Link to comment Share on other sites More sharing options...
ruthless Posted August 19, 2008 Share Posted August 19, 2008 http://www.msnbc.msn.com/id/26286459/ ...and i need to take an economics class. bwahahahaha! methinks they should rename the class to "short-term moneymaking 101." Link to comment Share on other sites More sharing options...
RainmanTime Posted August 20, 2008 Share Posted August 20, 2008 "How is your effort going to get into school, ruthless?" ill be moving onto the msu campus soon. Excellent. Keep me apprised of how it goes. You will soon learn many new things, and whether you believe it or not, you will also learn that some things you thought were true...are not so much. RMT Link to comment Share on other sites More sharing options...
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