/sci/ - Science & Math

>>1862959so how do i stack them safely!?

Don't. Just use them on other things.

Wooden clamps.
and a drill press.
or something else big and heavy and strong. Like your mother.

What do you want to use them for?

Stacking them seems like a really bad idea... How are you going to UNstack them later?

that would have been pretty epic

Anonymous killed by magnets

>>1862975

holy fuck though, i spent about 2 hours pulling off the three pieces off the big one.

and im so fucking scared of magnets now

so i shud not stack them? instead should i buy a bigger magnet?

>>1862981
Why stack them at all? Seriously tell me.

out of curiosity; how do they ship these things? The packets should stick to any and all metal and destroy electronic devices along their route to your home. How?

magnetshowdotheywork.jpg

Wrap them individually in bubble-wrap until their magnetic fields are strong enough to lightly attract one another, yet not strong enough to be a pain-in-the-ass to get apart.

if you really want to stack them:
get a stack of textbooks about 3 feet thick, and remove the books one at a time until you have stacked them

and now you will never unstack them

>>1862987
to make a super magnet.. duh

>>1862995

thats a good idea

but in conclusion, i decided to not stack them

my house almost caught on fire due to the sparkage

and i thought i was gonna die

seriously, /sci/ i never knew magnets were so fucking into wizardy.
>>1862988

it was in like a 20 ft roll of bubbleroll and a big box

>>1862988
anti-ferromagnetic packaging

Hollow them out into shells to make a solenoid bb gun.

Did you buy those magnets or what?

I'm asking because I'd love to have them around.
Just think of the possibilities!

>>1862981
Christ, I lol'd.

I've been looking at large (2"x1"x"1) Neodynium magnets for the past hour for a gift, and then this thread appears. Confirms my suspicions that this will end badly. Still buying them, though.

>>1863027

yeah, i bought two for 20, someguy sent me two even though i payed for one on ebay

they are fucking dangerous, i cannot explain the power of these fucking magenets

>>1863032

how do magnets work?

>>1862959
hate to say it but this is a fine example of someone having more money than they have sence.
so what did you think you were doing?
making a 2011 Trollgod 6000 magnetcar? O_O
send me the money and you would be amazed at what can be done with it.

lololo one google later:

amazon.com - two 91lb neodymium magnets, $10

>>1862988
>The packets should stick to any and all metal

Especially powerful permanent magnets are enclosed in a steel box or can of appropriate thickness for shipment. The magnetic field will not extend beyond the steel.

Weaker magnets may be shipped in bubble wrap, which can lead to hilarity as shippers invariably use too little. Case in point: I ordered some cheap neodymium disc magnets from China which took over two weeks longer than expected to arrive. They had taken several trips in the wrong direction because the bubble pouch they were sent in kept attaching itself to vehicles, shelving and other parcels.

>destroy electronic devices

No. They might demagnetize magnetic media if close enough, but magnets do not simply destroy electronics like you're suggesting.

>http://www.amazon.com/Disc-Package-Earth-Neodymium-Magnets/dp/B000TK7UPY

>N40 4" x 3" Disc , Package of 1 Rare Earth Neodymium Magnets
>Price: $449.99
>* Neodymium Iron Boron (NIB) Rare Earth Magnets
>* Package of 1 Magnet
>* Grade - N40
>* 4" Diameter x 3" Thick
>* Pulling Force - 990 lbs

>>1862981
>instead should i buy a bigger magnet?
oh god i lol'd

>>1863095
>*Warning* This magnet is EXTREMELY dangerous and should only be handled by supervised professionals.
>Amazon

>and about 3 ft away

i don't think so tim. no permanent magnet that a single person can carry around can do much of anything from 3 feet away.

>>1863055
you will not buy a magnet for 10$ that will affect another like magnet at a range of 3ft and have the effect described

having years of experience with big magnets, i call bullshit on your story. especially the action at 3 feet and the sparking.

>>1863055

Too weak. 91lb of pull force attenuates long before 3ft.

>>1863139

>Implying he paid 10$ when he clearly said he paid 20 for one and got a second one free.

I would have liked to see the faggot OP screaming like a little bitch at the sight of a pair of magnets having sex.

>>1863176

9100 lb of pull force attenuates long before 3 feet

http://gizmodo.com/5156490/guy-loses-a-chunk-of-his-finger-in-neodymium-magnet-accident-nsfw

Rare earth magnets are plated with nickel, resins or other platinum-family metals. None of these things spark when struck.

Mutual attraction at 3ft is physically impossible for any known permanent magnet. At that distance the inertia of the magnets' weight will overcome their magnetism. Inverse square law places strict limits on the distance at which your magnets will act.

That's not to say that powerful neodymium magnets are not dangerous though, because they are.

>>1863266
you are retarded.
inverse square law places no limits. F=ma
so as force goes to zero, so does a, but while there is a finite distance between them, there is still an acceleration.

This is why physicists piss me off.

>>1863320
go to bed billy

>>1863320
Unless you've got antigravity in your living room, those magnets aren't going to drag themselves across your carpet at a distance of 3 feet no matter how big they are.

>>1863330
not billy, nice try. It isn't even 8 o'clock.

>>1863320
>but while there is a finite distance between them, there is still an acceleration.

you claim physicists piss you off while assuming magnets are frictionless spheres with no other forces at play? srsly?

>>1863340
and if they're both 3 feet cubed?
how about if they're on little carts?
and who said anything about carpet?
again, physicist making assumptions.
and if you aren't a physicist, you're still addressing this from a physicist's point of view.

>>1863348
The original point wasn't anything to do with friction, it was about inertia, and it was incorrect.

And that's why physicists piss him off.

>>1863348
You're right, I should have specified that there was a force, that could potentially overcome other forces to cause acceleration. But the neglect of any force on a free body is frustrating.

All the clowns in this thread are insane...

>>1863400
what posse? I don't see a posse here.

>>1863352
>and if they're both 3 feet cubed?

Given that the separation is three feet, guessing at the size of the magnets is irrelevant.

(the stated sale price sets some practical limits far below 3ft cubed though)

>how about if they're on little carts?
>and who said anything about carpet?

As per the OP:
>i put one on the floor, and the other in my hand

Could be waxed hardwood floor for all we know but they're still not going to overcome their static coefficient of friction at that distance.

We're operating on the variables as provided and presuming nothing about what was omitted. It sounds like you're making some of those assumptions you mention.

The OP has clearly lied about this little experiment as real magnets would not behave in the manner described under the conditions described even if we had free reign to tweak the omitted variables.

I have acquired a neodymium magnet 4" by 1" by 1" with a pull force of 273 lbs. What sort of havoc can I wreak with it?

>>1864231
Sew it up in a dear carcass, and then stick it to someone's car door.

>>1864231
Get yourself some steel ball bearings and make yourself a gauss gun. Just be careful not to kill anyone with it. Putting 273 lbs of force into a quarter inch steel projectile can be very dangerous.

>>1862959
fluids!

Water or something with even greater density.

IE - Drop them in a pool or something and push them closer together with a stick.
The density of the liquid will slow the magnets' acceleration and hopefully reduce the impact force enough to keep them from breaking.
Combine this with another method like a brace between them which is reduced until they are very close so they do not have much time to accelerate.

tl;dr - Shit's hard. Magnets are awesome aren't they?

>>1864269
Conservation of energy has something to say about the effectiveness of this gun. Projectile will only go as far (not even) as the original distance between the ball bearing and the magnet.

>>1864269
>>1864281
Agree.

This is why Gauss guns are better done with electromagnets.

>>1864281
Although one might still do some damage to human flesh at point blank and a starting ball distance of about 10 cm.

Would be interesting to test just for fun.

>>1864281
Incorrect. The bearing that gets fired is farther out of the magnetic field than the final resting spot of the trigger bearing, but gets all of the momentum from the trigger bearing.

tl;dr yes, they work

>>1864281
Newtons 3rd law actually. Force of the projectile exiting the gun is equal to the force of the object striking the magnet. So ideally, using the picture as a reference, you would want the ball that's striking the magnet, the one furthest on the right, to be much much much larger than the ones to the left of the magnet. Also you'd only want 1 ball on the left and it would be best if the ball on the far left, the projectile, was non-magnetic. This way no energy is lost due to the attraction of the projectile to the magnet. You'd still need to get the projectile as close as possible to the magnet before the striker ball hit the other side. maybe an slight incline would keep it in place. You'd still loose some force due to friction but it could prove to be quite energetic.

>>1863246
If you've ever played with the small Nd magnets out of hard drives then you would know that this story is not far fetched at all.

The Nd's out of hard drives attract each other at 6 inches apart no problem and they spark like a mother fucker if you let them crash in to each other from that far apart.

A few magnets that weigh a few pounds could certainly come close to feeling a strong attraction at 3 feet and if not then it wouldn't be much less - so maybe he exaggerated a little bit, this is still completely plausible.

I don't believe you have any experience, sir.

>>1863157

lol'd

That shit's real though, the Nd magnets out of hard drives will pinch the shit out of your finger and those are several time larger. I bet that dude felt like an idiot.

>>1864321
You're assuming that there is an inverse relationship between the size of the magnet and the strength. Magnets have an inverse cube relationship. This means that for every X distance increase, there will be x^3 less force from the magnet. There is a practical limit to the range of magnets. The most powerful magnets in the universe (pulsars) only cause a significant effect at a few million miles.

So what would an nd magnet do to say..the electronic push button box to enter a building or a cell phone if swipe across?

>>1864349
>remarkable things happen within a magnetic field of magnetar strength. "X-ray photons readily split in two or merge together. The vacuum itself is polarized, becoming strongly birefringent, like a calcite crystal. Atoms are deformed into long cylinders thinner than the quantum-relativistic wavelength of an electron."

The most magnetic objects in the entire universe will tear you apart at a range of 1000KM because of the diamagnetism of water.

Yet if it were a bit further away, like as far from us as the moon is it wouldn't even erase our credit cards.

If it were as far from us as the sun the effects would be completely negligible next to Earth's own magnetic field.

>>1864356
Disrupt radio signals for the phone when it's nearby. Possibly fuck with the battery as well.
Otherwise, nothing.

>>1864414
li-ion/li-poly batteries aren't particularly bothered by magnets.

Handy dandy magnet force calculator.
http://www.kjmagnetics.com/calculator.asp?

>>1863095

>buy a dozen of these
>put them on someones' car.
>laugh

Bump

>>1864440
http://www.kjmagnetics.com/proddetail.asp?prod=BZX0ZX0Y0-N52

>4'' x 4'' x 2''
>1200lb pull force

Try that on for size.

Pro tip: Don't try to grind rare earth magnets to size in air. Many sparks, followed by showers of flame and noxious fumes. One of my techs did this - awesome display, nearly burnt the shop down.

Pic related: Aluminum powder in paint on Hindenburg

OP, Get a 5 gallon bucket and fill it with like 1/3 corn starch and mix in water until it is bout the consistency of clay, once the corn starch is saturated, drop one magnet in the bottom of the bucket and just drop the other magnets one at a time into the bucket. they will connect and then sink. the repeat till they are all together.