Electromagnetic Propulsion

[larper]

sin and cos are functions. Mathematically, they are not usually written with parameters around the angle (argument), but they can be. If you write software, you will understand them better as sin(A) and cos(A).<br /><br />For the definition of what sin and cos are, wait until you take trig. No use wasting your summer vacation on that!<br /> <div class="Discussion_UserSignature"> <p><strong><font color="#ff0000">Vote </font><font color="#3366ff">Libertarian</font></strong></p> </div>

 

[somispin]

Where A = A complementary angle:<br />sin A = (side opposite to A)/(long side)<br />cos A = (side adjacent to A)/(long side)<br /><br />What does that have to do with the problem is what I am getting at?

 

[larper]

It shouldn't. I tried to make the system as simple as possible to avoid getting into trig and vector math. The math is really very simple. It is just that once you start dealing with vectors, you have to start to talk trig. By simplifying the problem that way I did, I was hoping we could stick to "scalars" and simply talk about adding up the forces.<br /><br />But, to be absolutely correct, you cannot talk about forces without talking about vectors. And when you talk about vectors, you have to use trig.<br /><br />To really understand it all, you have to take Linear Algebra. To really really understand it all, you have to take Modern Algebra. <br /><br />You will get there in no time. What grade are you going into this fall? <div class="Discussion_UserSignature"> <p><strong><font color="#ff0000">Vote </font><font color="#3366ff">Libertarian</font></strong></p> </div>

 

[somispin]

Going into gr 9. this fall. Took Linear Algebra last year. Trig and vector math comes this year. Wanna see if I can figure it out before the year starts.

 

[somispin]

Thanks for the post Tigerbiten. Will look at the math tomorrow and see if I can figure it out.

 

[larper]

I don't think you took Linear Algebra yet. In 8th grade you would take basic Algebra. Linear Algebra is a college level course.<br /><br />Linear Algebra deals with coordinate transformations, solving systems of linear equations (polynomials with multiple unknowns with no exponents), and matrix math. Linear Algebra points out that there are many similarities to these seemingly different concepts, and is one of the first "unifying" concepts in mathematics. <br /><br />Trig is probably the very first "unifying" concept. By unifying, I mean that first, you learn geometry. Then, you learn algebra (or vice-versa). There seems to be little in common between them. Trig shows that you can solve geometric problems algebraically.<br /><br />When you take Calculus, you use mostly algebra and trig, and you are introduced to vectors and limits. Linear Algebra shows that vectors are simply another set of 'numbers', and so can be treated just like any other number algebraically.<br /><br />Modern Algebra is usually a senior level class in college. It is the ultimate in unifications, and shows exactly why all of these different kinds of numbers can be treated the same. It also proves that there are NO other sets of numbers that we don't know of. <br /><br />edit:<br /><br />Of course, this all is based on the HS curriculum I went through 25 years ago. Back then, trig was all about how to use Trig tables. In 12th grade we were taught how to use logs and log tables. Nobody had calculators in class. <div class="Discussion_UserSignature"> <p><strong><font color="#ff0000">Vote </font><font color="#3366ff">Libertarian</font></strong></p> </div>

 

[drwayne]

The funny part is that I avoided taking a dedicated course in linear algebra all the way to my Ph.D.<br /><br />I learned it piecemeal on my own along the way. (A lot of it also comes up in E&M, Optics, various Physics Math Methods courses, and of course the magnetic resonance work I did.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[drwayne]

As a 1st semester calculus instructor of mine pointed out forcefully, what screws up people starting calculus is not calculus. its algebra.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[larper]

<blockquote><font class="small">In reply to:</font><hr /><p>The funny part is that I avoided taking a dedicated course in linear algebra all the way to my Ph.D. <p><hr /></p></p></blockquote><br /><br />Hehe. I had a double major Math/CompSci, with a physics minor. I decided to take Mathematical Physics for one of my minor electives courses. This was in my senior year. Everyone else in there was taking it as a requirement for their physica major. Most of them had taken the bare minimum of math classes. <br /><br />It was kinda funny watching them struggle. It also was interesting to see how a physics professor taught math. Everything was by example, not theorem. For instance, eigen vectors were introduced and shown how they could be used to solve problems. But what they actually were was not told to the students. In the end, it seemed that all of the physics majors learned things by rote. Math majors seemed to be better at generalization and abstraction.<br /><br />I certainly run into this every day at work.<br /><br /> <div class="Discussion_UserSignature"> <p><strong><font color="#ff0000">Vote </font><font color="#3366ff">Libertarian</font></strong></p> </div>

 

[somispin]

What are your professions? I am guessing, strongly, that they are involved somehow in the mathematics/physics department. <br /><br />When I said that I had studied linear algebra in the above post, I meant linear equations and regressions. I got a bit befuddled with the two. My mistake.

 

[drwayne]

Thats interesting - eigenvectors, and later eigenfunctions were something I did well with and enjoyed. <br /><br />As an undergraduate, math methods was taught by a remarkable fellow in the physics department who I also took undergraduate E&M from. He was a very conceptual guy who taught a non-credit course every year in wine tasting that was booked a couple of years in advance (this was Vassar after all). I owe him my understanding of orthonormal functions.<br /><br />The book I used, by Mary Boaz is still on my shelf at work - and gets hauled out periodically some 26 years after I took the course - god, its been that long....<br /><br />As a graduate student, I took math methods and a course in special functions from another unique man in the math department. When you first went to one of his classes, he graded you VERY hard, but once you proved yourself, he would ease up. But, the funny part is, he was such a fine gentleman that you never eased off, because you didn't want to let him down.<br /><br />One other funny math related story. One semester at Vassar, I needed to take an elective course, outside of my curricular division (its a liberal arts school and all) - so I spied a solution. I took a statistics course - from the economics department. My advisor gave me a look that seemed both angry and amused and said "Wayne, I think you are skirting the intent of the rules here".<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[drwayne]

I am a physicst by education. (B.A., M.S. and Ph.D.). Since I got my doctorate I have worked in industry, first in a lab doing a lot of materials science work with HgCdTe and related IR semiconductions, and then later did all manner of optical modeling, software development, scene generation modeling hardware and software, propulsion and plume analysis and modeling - joke writing and other picture postcards.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[drwayne]

One more funny story that has at least a tangential connection to this thread:<br /><br />When I took my Ph.D. orals, one of my committee members was a notorious hard ***. He had given me more than my ration of stuff in a couple of courses beforehand, but I had asked for him on my committee.<br /><br />In oral exams, they basically gave you a piece of chalk and sent you to the board, and asked you to solve various problems from your required graduate courses. This fellow got this **** eating grin on his face when he asked me to derive the distance from the sun at which a particle of a given size would be in equilibrium (gravity versus radiation pressure).<br /><br />So I said to him, "You haven't given me some needed information", at which point he stated in a snotty fashion that he had. Finally, after I repeated that there was missing information, he got exasperated and asked what I *thought* was missing from the problem statement.<br /><br />"You forgot to tell me whether the particle's reflectivity, it makes a difference of as much as a factor of 2 in the solution" - he realized his mistake and told me do it for a relectivity of 1. Two other committeee members stated I passed right there. The problem is solved by the way by conservation of momentum - in this case, the momentum of the photons.<br /><br />The funny part is that I had to do the problem as an undergraduate - from another fine gentleman at Vassar, so I already knew the answer. <img src="/images/icons/smile.gif" /><br /><br />I know, I'm boring everyone - this just got me thinking about school...<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[vidar]

Space has no molecules/atoms that surround the vessel. Energy as heat (or noise) can not eb away into space. <br />Surely you realise that.

 

[vidar]

You are making a very creative approach Tap_Sa

 

[vidar]

Let’s make such a law!<br />‘Black boxes in space are not allowed to move.’<br />That would be the UN charter version.<br /><br />For scientist the prohibition would be;<br />v = m / 0<br />It should have some extra square roots, logarithms etc to impress.<br />Talking about quarks would also prevent questioning the law.

 

[vidar]

Tap_Sa said<br />‘I know only one credible theory that appears to create thrust seemingly without throwing reaction mass.’<br /><br />Does it have to be reaction mass?<br />Can it be reaction energy?<br />There is a relation between mass and energy, you know.

 

[nacnud]

<font color="yellow">Energy as heat (or noise) cannot ebb away into space. <br /><br /><font color="white">Yes it can, although the correct term is radiate.<br /><br /><font color="yellow">Can it be reaction energy? <br /><br /><font color="white">Yes, a photon has momentum. Shine a torch in one direction, and there will be a very, very small push in the other direction.<br /></font></font></font></font>

 

[siarad]

That's so easy.<br />When tying the rope the weight of the tower above is trying to pull the rope down but can't move due to the tower below but the tension is high so breaks the pole <img src="/images/icons/laugh.gif" /><br />I'm not an English major honestly

 

[starfhury]

Well this whole thread got me thinking and doing some additonal digging around on the 'net. I found this link discussing a potential electromagnetic propulsion system. It's an interesting read. I can't say I like the way Vidar is going about explaining his theories here, but it's still an interesting discussion.<br /><br />I guess the big obstacle we are still trying to over come is whether we can accelerate an object with out tossing mass overboard. It would be much more mass cheaper to just toss energy overboard instead. For example, a really powerful solid state laser drive converting electrical energy into photons to toss overboard. Who knows, perhaps a couple hundred gigawatt laser pulses with power from a nuclear/fusion/antimatter reactor. By pumping out a ton of photons rapidly, you can achieve an in space only propulsion system. Of course, I wouldn't recommend locating yourself behind that sucker. Well, not unless you think vaporization is good for your health. <div class="Discussion_UserSignature"> </div>

 

[siarad]

There's nothing magical about sin & cos although you may come to think there is about tan.<br />They are simply a set of tables some-one has calculated to save you trouble.<br />If you push a wheeled vehicle it always moves in the direction of the wheels. So push one & you naturally push in that direction. If you pushed at 45 degrees it would still move but would be very difficult for you. Looking up these tables for 45 degrees would give you the difficulty i.e. only 70% of your energy is pushing forward nothing magical or difficult.<br />Of course at this angle it's easy as it's a right angle plane equilateral triangle giving the hypotenuse as root 2 so the vector is easily calculated. You are dividing the base by the hypotenuse called cos. Not so easy at other angles so the tables enable a quick lookup.

 

[vidar]

I agree that the energy in form of elmag waves (like radiation and light) can escape the vessel. But heat, as vibrating molecules, can not if space is completely empty at the site.<br /><br />This might also be the clue for the lack of ‘throwing reaction mass’, in order to have the vessel moving forwards. If ‘throwing reaction energy’ is good as well, there might be a solution based on energy rather than mass. (Note, there are relation between energy and mass, like e=mc^2.)<br /><br />Quite frankly, the hammer propulsion is not my favourite idea. I started that as an analogy to the hammering of molecules at the back of a rocket burning chemical fuel.<br /><br />Very hypothetically, I would rather see the elmag pushing its ship forwards without a mechanical hammer in between. I can see that there would be a counterforce, as for a chemical propulsion in a closed system.<br /><br />The question then is, since there is a relation between mass and energy, would letting out energy at the back, in stead of mass, make the vessel move forwards? <br /><br />Why, or why-not?

 

[siarad]

We may laugh about this due to the impossibility of your example.<br />However nature seems to manage this with em waves.<br />Light jumps off at velocity C & continues at this forever.<br />Now there's a lot of gravity around to which it seems impervious neither slowing or speeding.<br />When encountering a compact source it seems to be transparent too except that it is deflected. Ring a bell, well we do the same sling-shotting around planets which neither add or remove speed from the probe.<br />The difference is when heading to or from gravity where light amazingly keeps at C. This must use some form of energy pushing or pulling just as you say & likewise is impossible unless it's acting against space itself.<br />So your idea isn't so silly, just it's implementation & you need to discovery how to transfer this space energy as does light.

 

[nacnud]

<font color="yellow">The question then is, since there is a relation between mass and energy, would letting out energy at the back, in stead of mass, make the vessel move forwards?<br /><br /><font color="white">Since there is a relationship between energy and mass you can’t have one without the other. You couldn’t propel yourself with pure energy because there is no such thing. The closest you can get is to use photons. <br /></font></font>

 

[nacnud]

<font color="yellow">So your idea isn't so silly, just it's implementation & you need to discovery how to transfer this space energy as does light. <br /><br /><font color="white">Eh?<br /><br />Light moves at the same speed whatever but it does change in energy depending on the velocity of the moving source. Lets consider a torch moving forwards at speed in relation to an observer. Light coming out of the front of the torch has more energy, its has a higher frequency than light coming out the back of the torch according to the stationary observer.<br /></font></font>