It’s such an oft repeated warning that it’s firmly embedded in nerd lore: bring a magnet anywhere near your precious computer and suffer the dire c***equences. But is true? Is your computer one run in with a novelty magnet away from digital death?

今天的问答环节是由SuperUser提供的，SuperUser是Stack Exchange的一个分支，它是一个由Q&a网站组成的社区驱动分组。

问题

尽管反磁铁规则屡屡被重复，以至于成为法律，但它实际上是硬件安全的硬性规定吗？超级用户读者Aequitarum Custos想弄清这一切：

When I first started using computers, law of the land in computer class was never bring magnets near anything computer related, lest you lose all your data or screw up your monitor.

Now I am pretty sure magnets will still royally mess up a standard hard drive, and I know for a fact they screw up a CRT monitor.

Though I am also pretty sure they do not screw up a LCD monitor?

Now I have my phone which uses magnets to determine if it’s docked, and it made me wonder.

Is it the power of the magnet preventing data loss or the sheer fact that whatever memory type in the phone is immune to it?

What about ear buds, as I know those have tiny magnets in them. Are those capable of damaging any electronic device currently in use?

I’m wondering if I’m being paranoid, but I really am not sure what magnets will damage and what they won’t!

Is there a list, or rule of thumb for determining what will be hurt by magnets and what won’t be?

任何打开旧CRT显示器附近或顶部的台式风扇的人都可以肯定地证明发生了什么事情，就像屏幕上喷发的彩虹的狂野图案所表明的那样，但那是永久性的损害吗？

答案

超级用户贡献者Synetech解释道：

A list or rule? Sure, anything that uses electro-magneti** to function could, and would be affected by magnets. The question is what the detrimental effects, if any, would be and how strong and close do the magnets need to be. Generally the two most questioned items are the monitor and disk drives.

LCD/LED monitors are not generally susceptible to magnetic interference like CRTs are because they function completely differently (remember, CRTs use magnets to deflect the electron beam, so an external magnet would obviously mess with that).

Hard-drives are also not affected by magnets because of the way they function. You can research the details on how hard-drives work for a more thorough understanding, but the easy answer is that there is a very powerful magnet inside each hard-drive that controls the read-write head’s movement. That’s why some people like to rip open dead drives to get at the sweet, gooey super-strong magnet inside. If that magnet that is inside the drive, right beside the platters, and it doesn’t wipe them, then any magnet that you are likely to have around isn’t going to.

As for flash drives, they are a different technology altogether so they are not going to get erased.

There is one component however that is indeed affected by magnets that most people miss: cables. While many cables are shielded, some are not and thus susceptible to a magnetic field. For example, a cable connecting the sound card to the speaker may be shielded, but the little cable connecting the CD/DVD drive to the sound card usually isn’t and ingress of a magnetic field could cause interference. Or, while rounded IDE cables (especially for IDE133) are usually shielded, ribb*** usually aren’t and even at speeds of 66/100 could be affected enough to cause some corruption or at least reduce performance due to re-tried reads/writes.

I would say that modern systems are not really vulnerable anymore because as time progresses, science and knowledge advances, but unfortunately that’s not sufficient. While that may be true, in the old days things were done right a lot more than today with all the cut corners and cost-reducing measures (eg NVIDIA’s “Bumpgate”).

Anyway, the point is that when it comes to modern computers (I’m counting floppy disks as not-modern), you don’t really need to worry about magnets. You can breath a sigh of relief. :)

虽然这回答了问题的实质，但你必须对一个非常强大的磁铁极度疏忽，才能造成任何真正的损害，贡献者dmckee提供了一个例子，说明在一个非常强大的研究磁铁周围工作的效果：

I recall sitting at a computer on a major particle physics experiment when the big (10x5x3 meters, >100 t***) dipole magnet was being tested about 40 meters away. As they ramped it up the display would twist to one side by about 10 degrees. Hit “degauss” on the monitor front panel, ::blur:: then return and all would be well. Later, they’d ramp down, and the monitor would twist the other way…good times. Leave you wallet in your pocket and walk into the hall while they were doing that and you’d loose the data on the magnetic stripes on all your cards…bad times.

如果显示器和电脑塔架旁边的一块强大的磁铁不能永久地使机器停止工作，那么心不在焉地拍打在电脑机箱侧面的一张磁性名片肯定是不值得警惕的。

有什么要补充的解释吗？在评论中发出声音。想从其他精通技术的Stack Exchange用户那里了解更多答案吗？在这里查看完整的讨论主题。