Puzzled About Magnets

Work refers to an activity involving force and movement.

In your scenario gravity is being overcome by friction.

The magnetic force in the Halbach magnet is being put to some serious energy-saving uses, apparently..

http://www.eurekalert.org/features/doe/2004-11/ddoe-mlt111104.php

In physics class mechanical work is the energy transferred by a force acting through a distance. I remember the teacher explaining that if a student picks up a 80 pound bag of concrete from next to his/her chair, runs around the physics building carrying the bag and then returns the bag and sits down then, since the bag's position (distance) did not change no work was done. The refrigerator door only moves during commercials so with respect to the magnet there is no distance moved. No move, no work.

If you really want to be confused about the definition of "work": there were some people who got paychecks at the last place I worked ... sorry, if I finish this I might get reported for "off topic".

The bottom line, since you think that the magnets are doing something useful then they are doing work as defined by you. If you want a good grade in physics class you need to use their definition of work.

Brilliantly clear for a 6 to a 60 year old. GA

Okay. I got it so far.

So here's the kicker:

I take my sons marble-runner-track that includes a banked turn, and three inches away from the banked turn, I place a huge magnet. As the marble rolls within the grooves of the track and begins the banked turn, the magnet is so powerful that it causes the marble to jump the track and travel the distance between the gap until comes it comes to rest against the magnet itself. Equilibrium.

What is the "it" that caused the marble to deviate from the course that would have otherwise been taken - but for the magnet. And why can't a bunch of these "its" be lined up in a row to make work happen?

And supposing it could, for the attraction-repulsion challenges involved in using this concept to create a moving machine, does a Hallbach magnetic configuration make any difference?

Again, please explain in as simple a way as possible. Thank you!

"And why can't a bunch of these "its" be lined up in a row to make work happen?"

Of course, once the car goes by, the magnets pulling it in the other direction.

What you're talking about is basically one of these:

And it doesn't work.

Check out this site:

http://www.lhup.edu/~dsimanek/museum/unwork.htm#cheng

You have the right idea but I think he means alternating N and S towards the center so that you have one there to attract and the other to repel at the same time.

Clearly, I can't exploit the energy from coasting down a hill to return to the top of that same hill.

However, it's quite possible to exploit the energy from coasting down a steep hill to take on a number of less steep hills.

So for purposes of argument, let's assume my magnet holds the equivalent "it" of a 100,000 ft. downhill descent, but during my marble's anticipated lifetime, the marble will roll only 50% of that total distance.

Why are we assuming that pulling the marble around a bend has consumed 100% of the total "it" contained in the magnet? And to the extent that the Halbach array alters the balance of "push-pull" as the marble rounds the bend, is it correct to say that the marble would no longer have to overcome the same level of "it" (both pushing and pulling) that it previously encountered which left nothing in reserve to power it's continued roll?

Finally, refering to my previous post, how do we measure the "it" generated by the magnet that will pull the marble from its track over and over again? And if "it" can be measured, and if "it" is capable of exerting sufficient influence over a metallic marble, in motion, to change its course, then why can't that "it" be redirected in some other way to perform meaningful work?

Again, please make the explantion as simple as possible. Thank you!

(All this because I sat staring at the refrigerator door for no good reason!)

I had one other thought:

If I was being delivered a steady stream of rolling marbles every day that needed to be pulled off the track and dropped into storage boxes below, let's assume that I would hire an employee to do this for me.

Then one day, Lester, the owner of Less Attractive Magnets, Inc. tells me,

"Geez Dave, I gotta a new heavy duty Magneto-Monster rare earth magnet you can mount just off to the side over there that'll damn well knock those marbles right off the track and into those boxes you got sittin' there below. It'll do the 100% of the work of that new hire you keep bellyachin' about!"

If I installed the Magneto-Monster, from a physic's standpoint, would I be correct in saying the magnet was performing work?

Here is your problem. You are mistaking the energy of an object in a magnetic field for the energy of the magnetic field itself. Please consider the following example again.

When something rolls down a hill, you don't believe that the hill gave the energy to the object right? It was how high on the hill that you started it that determined the moving energy of the object at the bottom. The higher up the hill you start it, the further down the hill it goes. The hill is just there, it is in no way giving energy to the object. You couldn't somehow tap the hill itself for energy. The energy comes from bringing things up the hill then letting them go.

It is the same for the magnet and the marble. The magnetic field is just a hill (invisible). It is in no way giving up energy to the marble. The marble is just rolling down the invisible hill (called a potential in physics). There is no "it" of the magnet providing energy, just as there is no "it" of the hill providing energy for the rolling object.

To be absolutely clear here, you believe that the magnetic field has energy that is being used to alter the marble. This is INCORRECT. The marble is simply on a magnetic hill and rolling down. The stronger the magnet, the steeper and higher the hill, but in the end the hill doesn't give the object energy, only PUTTTING THE OBJECT ON THE HILL gives it energy. The hill just provides a way of converting potential energy (hill height energy) to Kinetic Energy (moving energy). It does not give any energy itself. It does not give any energy itself. It does not give any energy itself. It is just there.

Hopefully that makes it clearer.

"What is the "it" that caused the marble to deviate from the course that would have otherwise been taken - but for the magnet.

The "it" is electromagnetic force.

"why can't a bunch of these "its" be lined up in a row to make work happen?"

They can. That's exactly what an electric motor does. See the following site:

http://www.howstuffworks.com/motor.htm

One cannot think of a frig magnet in isolation, by that I mean when in position forces are in equilibrium, one then has to think of the magnet and the frig as one single unit. Removing the frig magnet is like breaking it off, the wound is a flat surface, but when you put it back it heals very quickly, and once again becomes part of the frig, not something separate hanging on, so gravity is acting on the frig and the magnet is part of it. There you are son, be a good boy, and go out and play.

Regards JD.

One thing that wasn't mentioned is Potential Energy (stored energy) which the menus have and this is released as you lift the magnet.

I have a similar fascination for centrifugal force assuming a cylinder spinning in a vacuum requires no additional work to maintain that spin, yet has all that Potential Energy stored.

Now leave me alone to play with my rare earth magnets and dream of saving the world.

Tony

After reading the last series of posts, I went to the USPTO.gov and found Patent #7,352,096. Now I'm really confused! What am I missing?

And would somebody please explain a Halbach Magnetic Array to me, and why it does or does not matter?

I'd also like to say that it's a little offensive to be made fun of when I'm asking questions, in good faith, about a subject matter for which I have little understanding. I'm 53 years old and never understood this stuff. I'd like to try now, and Q & A is the best way for me to do this.

When somebody asks me a legal question well beyond his or her depth, I welcome it as an opportunity to share some of what I've learned over the past 30 years. Believe me, there are plenty of engineers who would be left scratching their heads trying to properly apply the rule against pepetuities!

While I may not be an engineer, I look around and wonder why certain things are or are not possible. Sometimes I'm surprised to find that small industries based on a similar concept already exist. For example, going to a laser light show at Disneyland made me wonder whether or not there were certain gases that might solidify when coming into contact with high energy light. If so, I wondered whether we will someday tent a piece of property and "spray" the structural underpinnings of a new home into existence from a three dimensional laser projected blueprint. Well, we're not to that point yet, but the technology that will take us there is well under way.

I appreciate the effort the rest of you are making for hanging in there with me.

Laser can be used to solidify plastic powder and is used to make prototypes of plastic parts from a digital 3D model, as well as cut very accurately a range of materials from plastic to stainless steel. I share your desire to do other things with this wonderful tool.

Tony

I think you have had a great deal of good explanations with regards to your questions, you should understand we all like to drop a few humerus remarks in these posts I do not think it was a comment ill intended.

I could give you some answers but would only be repeating previous posts which for some reason always seem to be there ahead of my viewing a question as Sparky say I am on the end of a long line.

Your speculation on lasers is reasonable 3D sculpting has been done with lasers turning a gel into a solid, also a trip to the dentist would have your teeth rebuilt with ultra violet light turning the filling mixture into a solid.

I hope you have gleaned something from these posts which have given you lots of comments with which you can google up yourself and study the information available.

And would somebody please explain a Halbach Magnetic Array to me, and why it does or does not matter?

If you read about the train story from DOE I linked above, you'll see that they are saving energy by exploiting magnetic force. The principle is simple: since friction is a major loss of energy in machines, using magnets to reduce friction allows machines to function more efficiently.

The Halbach magnet is a man-made version where materials have been manipulated so that all the magnetism is working on one side of the magnetic object. As with the magnetic business cards you can buy in sheets. Nothing is attracted or repelled by the printed side, because all of the magnetic material has been aligned so that the forces work on attracting the card to the fridge. It's called an "Array" because it's made up of lots of tiny little magnetic particles which can be manipulated ie aligned in the way described, to make a magnetic coating with the force aligned in one direction. When two halbach surfaces are facing one another, they repel and thereby reduce or eliminate losses due to friction.

The same idea is being researched with nanomaterials, with the intent of making very efficient machines that have minimal losses due to friction.

it's a little offensive to be made fun of when I'm asking questions

no harm is intended in making a little fun. most of us are here to tickle our brains in one way or another. fun is intended like the halbach effect, to reduce friction not to create it. And I don't mean, to repel others, either. Think of CR4 as a coherent whole with many parts that must perforce grind against one another in places. Fun has its place, without causing the 'machine' to spit out pieces or fall apart.

IMO creative speculation about machines/technologies/physics is fun and also funny.

going to a laser light show at Disneyland made me wonder whether or not there were certain gases that might solidify when coming into contact with high energy light

according to my, ahem, textbooks, troll breath ... (Sorry, I found nothing else to match in my personal storehouse... I will read and learn with interest what more knowledgeable people have to say.)

When somebody asks me a legal question well beyond his or her depth, I welcome it as an opportunity to share

please direct me to the forum where you are registered and available to respond to questions. Law is a another area of interest to me, places to discuss it would be welcome. Thankyou.

Puzzled about what you are asking?

I love this site, and it has replaced watching the news for me.

Yes, some people respond to questions in sometime humorous or harsh manner, but that is due to their character or lack of one.

A few reminders.

The only dumb question is the one you did not ask.

The only thing that is impossible is not trying at all.

You are never too old to learn. You are never to young or old to teach.

Definition: Perpetual motion machine: Once it is build it would start by itself.

In both cases (broom and/or magnet) what keeps the paper in place is a friction force. In case of the broom it is the component of its weight depending on the angle between broom and floor (and subsequently broom and side surface of refrigerator) that determines the friction force.

For the magnet situation, there is a magnetic force that appears between the 2 sides of the magnet and which closes through the metalic refrigerator cover (one changed (+) - positive pole of magnet and the other (-) - negative pole of the magnet. This force is dependent on several factors, among them type of magnet, common area, level of magnetization, gap (distance between the magnet and refrigerator).

The magnet on the refrigerator does not fall from it because of the friction force between them. That friction force depends on the attraction force between the magnet and refrigerator and acts in the opposite direction as the gravitation force (since the magnet tends to slide downwards).

When inserting a paper (thin) between the magnet and refrigerator, the resulting force does change minimally, but since there is also a friction coefficient between magnet - paper - refrigerator, the whole assembly does not slide down.

If you insert several sheets of paper between the magnet and refrigerator, the force of attaction decreases and at one point the weight (gravitation force) exceeds the friction force and the magnet falls down (and with it all sheets of paper).

The energy level (potential energy) does not change, since the height of the magnet remains constant, but there is an amount of (mechanical) work required initially to position the magnet at that location.

food for more thought follows

It's confirmed: Matter is merely vacuum fluctuations *

19:00 20 November 2008 by *Stephen Battersby

For similar stories, visit the *Quantum World* Topic Guide

Matter is built on flaky foundations. Physicists have now confirmed that the apparently substantial stuff is actually no more than fluctuations in the quantum vacuum. ( Just as I suspected—nothing but manifestations of energy fields KEB) The researchers simulated the frantic activity that goes on inside protons and neutrons. These particles provide almost all the mass of ordinary matter. Each proton (or neutron) is made of three quarks - but the individual masses of these quarks only add up to about 1% of the proton's mass. So what accounts for the rest of it?

Theory says it is created by the force that binds quarks together, called the strong nuclear force. In quantum terms, the strong force is carried by a field of virtual particles called gluons, randomly popping into existence and disappearing again. The energy of these vacuum fluctuations has to be included in the total mass of the proton and neutron. But it has taken decades to work out the actual numbers.

The strong force is described by the equations of quantum chromodynamics, or QCD, which are too difficult to solve in most cases. So physicists have developed a method called lattice QCD , which models smooth space and time as a grid of separate points. This pixellated approach allows the complexities of the strong force to be simulated approximately by computer. Gnarly calculation.

Until recently, lattice QCD calculations concentrated on the virtual gluons,[what is a virtual gluon? Sounds like a 'financial engineered profit] and ignored another important component of the vacuum: pairs of virtual quarks and antiquarks. Quark-antiquark pairs can pop up and momentarily transform a proton into a different, more exotic particle. In fact, the true proton is the sum of all these possibilities going on at once. Virtual quarks make the calculations much more complicated, involving a matrix of more than 10,000 trillion numbers, says Stephan Dürr of the John von Neumann Institute for Computing in Jülich, Germany, who led the team. "There is no computer on Earth that could possibly store such a big matrix in its memory," Dürr told *New Scientist*, "so some trickery goes into evaluating it." [sounds like some more 'vapor ware']

Crunch time Several groups have been working out ways to handle these technical problems, and five years ago a team led by Christine Davies of the University of Glasgow, UK, managed to calculate the mass of an exotic particle called the B_c meson . That particle contains only two quarks, making it simpler to simulate than the three-quark proton.

To tackle protons and neutrons, Dürr's team used more than a year of time on the parallel computer network at Jülich, which can handle 200 teraflops - or 200 trillion arithmetical calculations per second. (obviously NOT using a Microsoft software tool—it would have 'crashed 100 times a day.) Even so, they had to tailor their code to use the network efficiently. "We spent an enormous effort to make sure our code would make optimum use of the machine," says Dürr. Without the quarks, earlier simulations got the proton mass wrong by about 10%. With them, Dürr gets a figure within 2% of the value measured by experiments.

Higgs field Although physicists expected theory to match experiment eventually, it is an important landmark. "The great thing is it shows that you can get close to experiments," says Davies. "Now we know that lattice QCD works, we want to make accurate calculations of particle properties, not just mass." That will allow physicists to test QCD, and look for effects beyond known physics. For now, Dürr's calculation shows that QCD describes quark-based particles accurately,(really?? 2% is a whole lot—that's more than the payload percentage of 'moon shot' rockets) and tells us that most of our mass comes from virtual quarks and gluons fizzing away in the quantum vacuum. The Higgs field is also thought to make a small contribution, giving mass to individual quarks as well as to electrons and some other particles. The Higgs field creates mass out of the quantum vacuum too, in the form of virtual Higgs bosons . So if the LHC confirms that the Higgs exists, it will mean all reality is virtual. –Does this finally mean 'its all in our mind' ????

thanks for this! I am truly thrilled to know that particle physicists have a quick calculation on hand to ensure that they don't successfully approximate a "biggish bang" at the Large Hadron Collider. Their first attempt was not a bit auspicious. The centaur Asbolus was on the ascendant in their chart. If they don't have the sense to consult an astrologer before setting these important dates, their chances of success are poorish. Of course, since matter is flakey anyway, we can hardly blink at the evidence that their engineering is flakey-ish as well.

Ah the whimsy, the cuteness of it all. Gluons, the post-it notes of the virtual office, mysteriously responsible for holding it all together...( there is a discussion of virtual gluons I mean stickies in a thread somewhere at CR4.. unless it has popped out of existence). True, the office is a mess and we can't seem to find these essential items when we want to read them. Time to do the quantum vacuuming so the place is tidy for his holiness Higgs Boson to say mass.

I personally feel that the physicists have overlooked a particle, something that might be termed the 'calvino' and which is fundamental to understanding that it is indeed "all in our mind". To experience this force see Cosmicomics http://www.amazon.com/Cosmicomics-Italo-Calvino/dp/0156226006 It shakes my atoms every time.

On the subject of fridge-magnetism: there is a Halbach effect producible with calvinos. I have seen it on TV. Researchers in Montreal routinely align calvinos in rows and invoke anti-higgs forces to lighten the mass in the array. Spectacular, and apparently, harmless.

You might find this web page more interesting.

Regards JD.

Hi JD ,

What a pity my sound card is kaput, I might have learned some wonderfull answer to all my problems the vidios certainly did not help much. I bet the company Steorn wishes he could get back all the energy he has expended so far for nothing!!

Could not go through all the threads but as per the basic what i learnt in physics is this

1) A work done is moving an object aganst a force. The person/ thing applying the force is the one doing the work and the object is on which the work is being done.

W= f*d

2) For the work done the subject loses an energy and the t energy is stored in the object.

Thus as the marble falls down the slope, no work is being done (since no energy exchange) but on the friction (or if it is allowed to hit a pelton wheel) a work is being done by it.

Similarly the magnet stuck on fridge/ cupboard door (ance it is stuck and is in steady state) no energy exchange and hence no work done.

It is as I remember - and since the thing was hammered long long back, the nail might have rusted and even decomposed. Any polishing is welcome.

Sb,

You are correct, with the exception of the statement "subject loses an energy".

Energy is never lost, it is transformed into other forms (potential, kinetic, mechanical work, thermal, etc). What is normally labeled as "loss" (in this case due to friction) is energy transformed into heat ( in both of the marble and the slope path) and dissipated in the environment.

(rephrase the subject transfers to the object - thats what i meant - subject loses and object gains )

When Potential Energy is converted to Kinetic Energy and vice-versa, work is done. That's because the gradient of the potential field is equal to a negative force. So when an object moves from a higher potential to a lower potential it is because the object experienced a force (gravitational force, magnetic force) that moved it. So by the Physics definition, work has been done.

Think of it this way, it takes work to put a rock on a table because you've changed it's potential energy in the gravitational field. If the table collapses and the rock falls, gravity has done work on the rock by applying gravitational force over a distance.