Can Magnet Doors Launch a Spaceshuttle into Outer Space Without Using Fuel?

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In summary, the conversation discusses a hypothetical scenario involving two mega-magnets with incredible pulling power and a giant spaceship made of ferromagnetic material. The main question is whether it is possible to use the magnets to move the spaceship without expending any fuel. However, experts point out that this is not possible due to the laws of physics, such as Newton's Third law, and the fact that it takes energy to shield a magnetic field. They also mention that a superconductor could potentially shield a magnet, but it has not been observed at room temperature. Overall, the conversation highlights the limitations of perpetual motion and the importance of understanding basic principles of physics.
  • #1
partisar1
I don't have a physics background but a debunking to this irrational thought process of mine would be much appreciated. I understand perpetual motion/energy is an old, dried, and silly topic, but I can't make sense of this, so thank you in advance for answering (and yes, it's to do with magnets).

This hypothesis doesn't rely entirely on perpetual motion, but consists primarily of it. I'm sure there's something basic I don't understand.

Hypothesis:

There are two mega-magnets with incredible magnetic pull, and an extremely focused, narrow scope (capable of pulling specific objects from within Earth's atmosphere from outer space). For the example imagine two identical mega magnets, M1 & M2.

M1 is positioned on Earth's surface, M2 is orbiting in outer space with just enough fuel to always keep it at an exact parallel with M1, but in outer space. For the example consider both magnets have the pulling power to pull a heavy object of equal distance to one another.

There is a giant spaceshuttle made of ferromagnetic material, sufficient enough in quantity to be attracted to either magnet if the other didn't exist (ie: if the shuttle was in the position of M1, but M1 didn't exist, M2 could pull it to itself, and vice versa).

Consider a scenario where M1 is built in such a way that it's based deep in the earth, with a giant non-ferromagnetic door that is capable of blocking the magnetic attraction. This door is capable of opening and closing independently of the magnet (using traditional power/electricity), and serves simply to block M1's pull. The same situation exists for M2 somehow (let's say instead of outer space it's based deep within the moon with the same door complex).

In order to move the shuttle from the surface of the Earth into outer space expending no fuel from the shuttle, would one not just need to close the door on M1's side, eliminating its magnetic influence on the shuttle and allowing M2 to pull? And when it's time to land, to put the door over M2 and allow M1 to pull?

Thanks.
 
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  • #2
One problem with your scenario is that magnetic pull goes both ways. If a magnet in space can pull the shuttle UP, the shuttle will, at the same time, be pulling the magnet DOWN. This is covered by Newton's Third law, which applies to attractions as much as it does to collisions.
As much as the shuttle is attracted to the magnet, the magnet will be attracted to the shuttle.
 
  • #3
If I'm not mistaken, you cannot "focus" the magnetic field in such a manner either.
 
  • #4
I had a nice 2 page write-up where I did all the math proving that this wouldn't be effective at all, comparing the energy uses to that of the shuttle et al. Also considering various outfits for M2 the satellite electromagnet, but when I submitted it, PF asked me to "please log in" and lost the whole post. So here is a little diagram that was part of it showing the work required to lift an object, provided you have a 100% efficient conversion through the different "types" of energy (which you never do). I do have a few of the final numbers written down, one of which was for the orbiting satellite to simply power the magnet (100% efficiency) it would require a solar array of 8 square miles, at 10-15% efficiency per cell.

24lkcnr.jpg


What a bummer, I was proud of that post, and spent the better part of an hour writing it.
 
  • #5
You cannot extract 'work' from a permanent magnet. It is a static field. You can temporarily get 'work' from a static field, like gravity, but, it is strictly temporary without an external energy source.
 
  • #6
If you could shield a permanent magnet without using energy, then you could have perpetual motion. Think about how electromagnets are used. They simply turn on and off at certain times, and can be used as an engine, to propel a roller coaster etc. If you shielded and unshielded a permanent magnet you could do the same thing.

But, it would take energy to shield the magnetic field. Whatever it is you use to shield the magnetic field, would need to repel the magnetic field which would be a force acting on both the magnet and the shield.
 
  • #7
QuarkCharmer said:
Also considering various outfits for M2 the satellite electromagnet...
His magnets are permanent magnets, though. He turns them on or off by means of a fictional non-ferromagnetic door that can block the magnetic field. No such material exists, which is another thing wrong with the scenario.
 
  • #8
There is no known material that can completely shield anything from a magnetic, or gravitational field.
 
  • #9
but you can distort the field with a ferromagnet, yes? that can do it to some effect
 
  • #10
Epidemius5 said:
but you can distort the field with a ferromagnet, yes? that can do it to some effect

That is an unrelated effect to what is being discussed.
 
  • #11
Drakkith said:
That is an unrelated effect to what is being discussed.

You can shield a magnet with a superconductor, but not for free.
 
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  • #12
Chronos said:
There is no known material that can completely shield anything from a magnetic, or gravitational field.

What about hard drive magnets? they are shielded on one side,disassemble one and check it out.
 
  • #13
jreelawg said:
You can shield a magnet with a superconductor, but not for free.

In theory, a superconductor could exist at room temperature. Unfortunately, such a material has never been observed.
 
  • #14
Here's an interesting article about magnetic cloaking.

To test the antimagnet, the Slovak group cooled the cloak with liquid nitrogen to activate the superconductor, and placed it in a static, uniform magnetic field with a strength of 40 millitesla. Using a measuring device called a Hall probe to map the magnetic field, the researchers found that the field lines did not enter the cloak, even through from the outside they appeared to pass straight through. They say that theirs is an 'exact' cloak — one for which the cloaking could, in principle, be made perfect using currently available materials.

http://www.nature.com/news/antimagnet-renders-magnets-invisible-1.10292
 
  • #15
bluey said:
What about hard drive magnets? they are shielded on one side,disassemble one and check it out.

Is that shielding for magnetic fields, or from EM radiation?
 
  • #16
Drakkith said:
Is that shielding for magnetic fields, or from EM radiation?

Its a shield for a magnetic field,if you take a hard drive apart you will see the neodymium magnet is super strong on one side and the otherside with the piece of metal on it has no magnetism at all. Don't ask me how it works I would like to know myself?
 
  • #17
bluey said:
Its a shield for a magnetic field,if you take a hard drive apart you will see the neodymium magnet is super strong on one side and the otherside with the piece of metal on it has no magnetism at all. Don't ask me how it works I would like to know myself?
Those magnets are magnetized in two places, toward the ends. The poles are switched. Hold it with the magnet side facing you and you will have a North pole at one end, a South at the other. There is a corresponding South and North pole on the other side of the magnet where the "shield" is. The magnetic flux on that side is confined to the metal. I've pried the metal off on several of them and confirmed the magnetization pattern with a compass.
 
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  • #18
zoobyshoe said:
Those magnets are magnetized in two places, toward the ends. The poles are switched. Hold it with the magnet side facing you and you will have a North pole at one end, a South at the other. There is a corresponding South and North pole on the other side of the magnet where the "shield" is. The magnetic flux on that side is confined to the metal. I've peeled the metal off on several of them and confirmed the magnetization pattern with a compass.

mmmm!very interesting. I will check it out when I'm feeling a bit better, I just broke a bone in my foot aaaaagh!
 
  • #19
bluey said:
mmmm!very interesting. I will check it out when I'm feeling a bit better, I just broke a bone in my foot aaaaagh!
Wow. Better get that taken care of.
 
  • #20
zoobyshoe said:
Wow. Better get that taken care of.

Ive taken a painkiller an anti inflammatory and I've got my foot elevated on a cushion, I won't be using magnets to try and cure it that for sure.LOL
 
  • #21
It doesn't shield it, its redistributed. So the field is no weaker, its just being bent around again. Look at http://en.wikipedia.org/wiki/Halbach_array this redirects the field very effectivley. A fridge magnet does the same to a much weaker extent. The HD mags can be taken off by simply twisting the ferrous plate. You will then find that the magnet is just as strong of either side and the plate is still not magnetic. Very interesting plate material for being so thin.
 
  • #22
Robin07 said:
It doesn't shield it, its redistributed. So the field is no weaker, its just being bent around again. Look at http://en.wikipedia.org/wiki/Halbach_array this redirects the field very effectivley. A fridge magnet does the same to a much weaker extent. The HD mags can be taken off by simply twisting the ferrous plate. You will then find that the magnet is just as strong of either side and the plate is still not magnetic. Very interesting plate material for being so thin.

No, a hard drive magnet with plate attached has nothing to do with a Halbach array.
 
  • #23
Chronos said:
You cannot extract 'work' from a permanent magnet. It is a static field. You can temporarily get 'work' from a static field, like gravity, but, it is strictly temporary without an external energy source.

So if there is an energy source... It won't be temporary?
If it were temporary it could last a long "temporarly" time :tongue:
 
  • #24
zoobyshoe said:
No, a hard drive magnet with plate attached has nothing to do with a Halbach array.
If it is not an halbach array causing this effect then what is it? Is the shield magnetized in sections to get the effect? This is getting confusing.
 
  • #25
bluey said:
If it is not an halbach array causing this effect then what is it? Is the shield magnetized in sections to get the effect? This is getting confusing.
A halbach array has no shield. It's a bunch of magnet segments cleverly arranged and glued to each other so one pole dominates and the other is suppressed.

A harddrive magnet with a shield on one side is doing something different. The magnetic flux from north to south is contained within the shielding material on one side and allowed to project out into space on the other.

A halbach array presents one pole on one side of the array and no pole on the other (it's there, just suppressed), a HD magnet with shield presents two poles on one side and two "contained" poles on the other.

The point of a A halbach array is to kind of "fake" a magnetic monopole, a thing that doesn't actually exist. The HD magnet with shield has two frank poles, there's no attempt at a monopole.
 
  • #26
zoobyshoe said:
A halbach array has no shield. It's a bunch of magnet segments cleverly arranged and glued to each other so one pole dominates and the other is suppressed.

A harddrive magnet with a shield on one side is doing something different. The magnetic flux from north to south is contained within the shielding material on one side and allowed to project out into space on the other.

A halbach array presents one pole on one side of the array and no pole on the other (it's there, just suppressed), a HD magnet with shield presents two poles on one side and two "contained" poles on the other.

The point of a A halbach array is to kind of "fake" a magnetic monopole, a thing that doesn't actually exist. The HD magnet with shield has two frank poles, there's no attempt at a monopole.
I now know what an halbach array is but the crux of my question is,what properties of the shielding material is causing this effect,how does it contain the flux?
 
  • #27
bluey said:
I now know what an halbach array is but the crux of my question is,what properties of the shielding material is causing this effect,how does it contain the flux?
I don't know how it contains the flux. All I can tell you is that it is a property of magnetic flux that it 'prefers' to concentrate itself in magnetic metals rather than space.

http://en.wikipedia.org/wiki/Magnet_keeper
 
  • #28
zoobyshoe said:
I don't know how it contains the flux. All I can tell you is that it is a property of magnetic flux that it 'prefers' to concentrate itself in magnetic metals rather than space.

http://en.wikipedia.org/wiki/Magnet_keeper

I think I have it worked out? The so called shield doesn't have any special properties at all, it is really a simple bracket/short circuit device,instead of shorting electricity, it is shorting the magnetic field close to the magnet so that it can't go out into space.
 
  • #29
bluey said:
I think I have it worked out? The so called shield doesn't have any special properties at all, it is really a simple bracket/short circuit device,instead of shorting electricity, it is shorting the magnetic field close to the magnet so that it can't go out into space.

That's pretty much it, yep.
 

1. Can magnet doors really launch a spaceship without using fuel?

Yes, it is possible for magnet doors to launch a spaceship into outer space without using fuel. This concept is known as magnetic levitation, and it works by using powerful magnets to repel against the Earth's magnetic field, providing the necessary force to lift the spacecraft off the ground.

2. How is the force generated by the magnets enough to launch a spaceship?

The force generated by the magnets is strong enough to counteract the force of gravity and provide lift for the spaceship. This force is also amplified by the Earth's magnetic field, making it possible to achieve the necessary acceleration for the spacecraft to enter outer space.

3. Are there any drawbacks to using magnet doors for space launches?

While magnetic levitation has shown promise for space launches, there are still some challenges to overcome. One major drawback is the initial cost of building and maintaining the necessary infrastructure for magnetic launch systems. Additionally, the magnetic field may interfere with sensitive electronic equipment on board the spacecraft.

4. What types of spacecraft can be launched using magnet doors?

Magnetic levitation can potentially be used to launch different types of spacecraft, including satellites and space shuttles. However, the design and technology used for each type of spacecraft may vary depending on their specific needs and capabilities.

5. Is there any research being done on using magnet doors for space launches?

Yes, there is ongoing research and development on using magnet doors for space launches. Several companies and organizations are exploring this concept, and some have even conducted successful tests and demonstrations. However, more research and testing are needed before this technology can be used for regular space launches.

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