# What would a magnet do to my laptop? **URL:** \ **Category:** Factual Questions\ **Created:** [June 13, 2008, 5:06am UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774 "2008-06-13T05:06:04Z")\ **Posts on this page:** 19\ **Page:** 1
**Author:** ![ManiacMan](https://avatars.discourse-cdn.com/v4/letter/m/b782af/32.png) [@ManiacMan](https://boards.straightdope.com/u/ManiacMan)\ **Post date:** [June 13, 2008, 5:06am UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/1 "2008-06-13T05:06:04Z")
If I waved a magnet close to my laptop would it destroy the laptop? ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [June 13, 2008, 5:26am UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/2 "2008-06-13T05:26:49Z")
No, unless it was exceptionally strong, stronger than you are likely to have access to. ---
**Author:** ![Jragon](https://avatars.discourse-cdn.com/v4/letter/j/e19b73/32.png) [@Jragon](https://boards.straightdope.com/u/Jragon)\ **Post date:** [June 13, 2008, 5:34am UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/3 "2008-06-13T05:34:57Z")
Really, I’ve (by pure accident) kept magnets next to my iPod in my pocket for half a day at least. No damage at all. I highly doubt you’d really screw it up unless you had some industrial level electro-magnet (even more powerful than I thought in another thread about wiping hard drives, apparantly they have to be immensely powerful, as in you’re not likely to having something that big or be able to get one easily or cheaply). ---
**Author:** ![control-z](https://avatars.discourse-cdn.com/v4/letter/c/eada6e/32.png) [@control-z](https://boards.straightdope.com/u/control-z)\ **Post date:** [June 13, 2008, 3:26pm UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/4 "2008-06-13T15:26:55Z")
Magnets hurt floppy disks and CRT monitors/TVs. But can’t think of anything in a laptop that would get hurt. ---
**Author:** ![Fubaya](https://avatars.discourse-cdn.com/v4/letter/f/c2a13f/32.png) [@Fubaya](https://boards.straightdope.com/u/Fubaya)\ **Post date:** [June 13, 2008, 7:41pm UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/5 "2008-06-13T19:41:53Z")
Would it not screw up data on the hard drive (assuming it was a small, fairly strong magnet waved directly over/under the drive)? ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [June 13, 2008, 7:44pm UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/6 "2008-06-13T19:44:38Z")
[QUOTE=Fubaya] Would it not screw up data on the hard drive (assuming it was a small, fairly strong magnet waved directly over/under the drive)? [/QUOTE] Unlikely. The magnetic field required to erase data on a hard drive is quite large. An AC electromagnet is a different story, but even then it takes a really strong magnet to damage a modern hard drive. Still, I wouldn’t make a habit of it. ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [June 13, 2008, 8:00pm UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/7 "2008-06-13T20:00:42Z")
At times like this I remember hearing someone say that a magnet strong enough to erase a flash drive would likely pull the iron right out of your blood. ---
**Author:** ![Valgard](https://avatars.discourse-cdn.com/v4/letter/v/7feea3/32.png) [@Valgard](https://boards.straightdope.com/u/Valgard)\ **Post date:** [June 13, 2008, 8:25pm UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/8 "2008-06-13T20:25:16Z")
[QUOTE=beowulff] Unlikely. The magnetic field required to erase data on a hard drive is quite large. An AC electromagnet is a different story, but even then it takes a really strong magnet to damage a modern hard drive. Still, I wouldn’t make a habit of it. [/QUOTE] As an experiment at work I took a hard drive out of a laptop and sat it on our heavy tape degausser (which also states that it is suitable for wiping hard drives). Followed instructions (turn on degausser, rotate drive several times, flip it over, rotate again). Made a horrible racket and you could feel the drive vibrating. Put hard drive back in laptop and turned the power on. It booted right into Windows as if nothing had happened. Like beowulff said, you probably shouldn’t make a practice of it but I doubt very much that it’ll do any harm if it happens once. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [June 14, 2008, 11:29am UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/9 "2008-06-14T11:29:15Z")
It might do something funny if you move it fast enough. It will generate currents in whatever loops of conductor circumscribe area through which its lines of force pass. Also, you should feel some magnetic field around the laptop, because batteries generate magnetic fields. This sounds surprising, perhaps, but it’s only because batteries generate power throughout some physically nontrivial volume, so you really can’t cancel the currents flowing through regions of a battery like you can those in wires you twist together. Batteries can’t be designed to funnel all the current through tiny regions close together, you see. So, in all the components inside the laptop, sweeping a magnet past it will generate little currents. At some point, maybe it would be enough to confuse things, give it a moment’s amnesia perhaps or trigger some reaction by imitating a signal. It might take a big magnet moving very fast to do it, though. ---
**Author:** ![shijinn](https://avatars.discourse-cdn.com/v4/letter/s/cc9497/32.png) [@shijinn](https://boards.straightdope.com/u/shijinn)\ **Post date:** [June 14, 2008, 11:52am UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/10 "2008-06-14T11:52:28Z")
so what can a normal magnet destroy then? ---
**Author:** ![chicken\_wire](https://avatars.discourse-cdn.com/v4/letter/c/a88e4f/32.png) [@chicken\_wire](https://boards.straightdope.com/u/chicken_wire)\ **Post date:** [June 14, 2008, 12:37pm UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/11 "2008-06-14T12:37:06Z")
My MacBook has small magnets to hold the case closed (instead of a latch) and another to hold the power lead onto the side of the case. I mean, they’ve designed them into the thing, little magnets seemingly aren’t a major concern. ---
**Author:** ![matt](https://avatars.discourse-cdn.com/v4/letter/m/a6a055/32.png) [@matt](https://boards.straightdope.com/u/matt)\ **Post date:** [June 14, 2008, 4:48pm UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/12 "2008-06-14T16:48:22Z")
[QUOTE=shijinn] so what can a normal magnet destroy then? [/QUOTE] Ye Olde Worlde floppy disks from medieval times didn’t do so well around magnets. You can also put a glitch on an cathode-ray-tube monitor or TV screen with a strong magnet… until you find the “degauss” function. (Warning - some don’t HAVE a degauss function!) Oh, and a couple of strong neodymium magnets can pinch you hard enough to draw blood if you’re careless. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [June 14, 2008, 7:18pm UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/13 "2008-06-14T19:18:29Z")
\>Oh, and a couple of strong neodymium magnets can pinch you hard enough to draw blood if you’re careless. They can also shatter if you let them play together under the wrong circumstances. And they can dimple the surface of water, hold a bismuth plumb bob noticeably out of verticle, and actually levitate a chip of pyrolytic graphite indefinitely at room temperature. They are a world of fun, even if a bit worrisome. ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [June 15, 2008, 12:04am UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/14 "2008-06-15T00:04:11Z")
[QUOTE=KneadToKnow] At times like this I remember hearing someone say that a magnet strong enough to erase a flash drive would likely pull the iron right out of your blood. [/QUOTE] I don’t know about that. I don’t think the second thing is even possible. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [June 15, 2008, 12:14am UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/15 "2008-06-15T00:14:44Z")
[QUOTE=msmith537] I don’t think the second thing is even possible. [/QUOTE] It isn’t. The iron bound up hemoglobin is actually weakly diamagnetic, like water, and is very slightly repelled by the application of an external magnetic field. ---
**Author:** ![Yorikke](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yorikke/32/4335_2.png) [@Yorikke](https://boards.straightdope.com/u/Yorikke)\ **Post date:** [June 15, 2008, 1:20am UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/16 "2008-06-15T01:20:07Z")
How about one of those [rare Earth magnets](http://www.sciplus.com/search.cfm/scategory/MAG/term/magnet)? Joe ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [June 15, 2008, 1:24am UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/17 "2008-06-15T01:24:49Z")
[QUOTE=wheresgeorge04] How about one of those [rare Earth magnets](http://www.sciplus.com/search.cfm/scategory/MAG/term/magnet)? Joe [/QUOTE] Neodymium magnets **are** rare Earth magnets. ---
**Author:** ![Maastricht](https://avatars.discourse-cdn.com/v4/letter/m/a88e57/32.png) [@Maastricht](https://boards.straightdope.com/u/Maastricht)\ **Post date:** [June 15, 2008, 5:58am UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/18 "2008-06-15T05:58:35Z")
We always hear that magnetic cards (ATM cards, membershipcards) should be kept away from magnets as well. At least there’s a warning to that effect posted on the counter in stores, where there’s a magnet under the counter to release anti-theft-tags. I’ve always wondered what harm little magnetic snaps/locks on wallets and purses could do to such magnetic cards. Apparently, not much, because they keep making and selling wallets and purses with magnetic snaps. ---
**Author:** ![MEBuckner](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mebuckner/32/2896_2.png) [@MEBuckner](https://boards.straightdope.com/u/MEBuckner)\ **Post date:** [June 15, 2008, 7:07am UTC](https://boards.straightdope.com/t/what-would-a-magnet-do-to-my-laptop/452774/19 "2008-06-15T07:07:03Z")
[QUOTE=Maastricht] I’ve always wondered what harm little magnetic snaps/locks on wallets and purses could do to such magnetic cards. Apparently, not much, because they keep making and selling wallets and purses with magnetic snaps. [/QUOTE] Apparently if the clasp is strong enough, [you can kiss your ATM card goodbye](http://www.straightdope.com/classics/a3_388.html).