When I was growing up, you had to keep magnets away from computers and other electronics. Magnets could single-handedly wipe drive and disk, and could play havoc with cables transmitting data. It was generally taught to me that these two should not be mixed with, barring the proper housing. However, magnets are everywhere with modern electronics and computers and it’s something that has been quietly puzzling me for quite some time now. Please someone, explain how this can be. I know there is a very simple answer to it, but my brain can’t conceptualize it.
In: 10
Magnets were only ever bad for very few technologies (CRT monitors, floppy disks, early hard drives) that are basically all obsolete now.
Well on a foundational level, electricity and magnetism are essentially two aspects of the same thing, because a changing electric field creates a magnetic field, and a changing magnetic field creates an electric field. (This is why physicists usually refer to “electromagnetism” or “electromagnetic” forces together, rather than separately.)
The main reason it used to be such an issue is we used magnetic storage, which could be wiped when exposed to a strong magnetic field. Whereas now we tend to use solid-state storage that is not affected in the same way.
Older computers used mechanical hard drives using magnetic platters. And floppy drives that were magnetic. Or even older ones using cassette tapes, or the various types of tape drives used as backups well into the 90s, all of which were unshielded.
Modern computers are a little less sensitive because they are mostly all electronic.
And other than the fans there haven’t been magnets near computers… well ever. Oh, magnetic tipped screwdrivers. Those would have been strong enough to damage magnetic media like floppy and tape drives. Not hard drives unless the platters were exposed and you put the tip close to one.
So still keep them away.
>When I was growing up, you had to keep magnets away from computers and other electronics. Magnets could single-handedly wipe drive and disk, and could play havoc with cables transmitting data. It was generally taught to me that these two should not be mixed with, barring the proper housing. However, magnets are everywhere with modern electronics and computers and it’s something that has been quietly puzzling me for quite some time now. Please someone, explain how this can be. I know there is a very simple answer to it, but my brain can’t conceptualize it.
It is very hard to damage a magnetic storage medium, be it tape or an HDD, with a magnet. The magnet needs to be *really strong* and *really close*. Realistically that’s only ever going to be possible with something like a credit card’s exposed magnetic strip and a neodymium fridge magnet in your pocket or similar. A magnet is much more likely to cause *mechanical* damage by suddenly snapping onto some fragile component.
All other kinds electronics do not give a damn about magnetic fields as long as those magnetic fields aren’t either *moving* or *changing*.
Devices used to rely pretty heavily on magnetism to function:
Data is/was commonly stored on floppy discs, hdds, cassette tapes, etc. All of which store their data in magnetic fields.
CRT TVs use magnetic fields to move an electron beam around drawing the image on the screen.
Bringing magnets near these devices interferees with the magnetic fields in the device causing problems. Maybe it just screwes up an image for a bit, maybe it permanently erases critical data that you don’t have another means of recovering.
Nowadays, data is mostly stored via electrical signals and the state of transistors in a flash memory module (within smalll devices like your phone). No magnets involved, so external magnetism isn’t an issue.
Magnetic storage is still used ofc (HDDs and tape drives). While it’s limitations are more understood and magnetic storage devices are better engineered to withstand exterior interface, they are still susceptible to some extent. Don’t go waving neodymium magnets at your pc hdd. Your gonna have a bad time.
TVs don’t use magnets anymore either. LEDs, LCD, etc. Cathode Ray Tubes are a thing of the past.
Old electronics used their own magnets to create magnetic fields. These fields need to be very precisely controlled to ensure correct operation and avoid damage. Outside magnets could overpower this control, disrupting or damaging things.
Specifically, hard drives and floppy drives work by moving little magnets in a physical disk using an electromagnet in the drive. Then, these drives read the magnets. An outside magnet, can force these little magnets to flip the wrong way, or overload the reader.
Furthermore, CRT screens use magnets to steer a beam of electrons into very specific places. Overpowering this magnet, will send the electrons off course. What’s worse, if the CRT contains ferromagnetic metal, it can be magnetized, causing the disruption to become permanent
Modern electronics simply don’t use the same sort of sensitive equipment. Hard drives are much better protected from magnets these days, and floppy drives and CRT’s are basically novelties.
And the rest of the computer doesn’t care. Computer chips use electricity, not magnetism. You can create electricity with magnetism, but this requires putting in energy. For modern devices, it takes a *lot* of energy. So much that it’s genuinely somewhat difficult even if you’re trying to break something, and an accident is basically impossible for a typical home user.
Now, as for long wires: magnets *can* interfere with signals. Any wire is an antenna. And any moving magnet, is a radio transmitter. Old electronics were analog – the accidental radio signal gets added to whatever you are trying to transmit, and the receiver can’t tell them apart, so it gets a distorted signal.
Digital electronics are much more resistant to this. Digital signals are created by switching the voltage in a wire. The reader measures the voltage, and if it’s in one range it reads ‘1’, and otherwise it reads ‘0’. As long as the signal picked up by the wire isn’t enough to push the data signal out of its intended range, the receiver doesn’t care.
More importantly: if you have two wires next to each other, they will pick up almost identical radio signals. And modern receivers compare the two signals to each other, so they flat-out don’t notice if both signals are distorted identically.
Further, it’s pretty easy to outright block these signals from reaching your wires. All you have to do, is surround them in a metal shield. The shield absorbs the magnetism, keeping it away from the actual signal wires inside.
You can still flat-out damage electronics like this, but once again, it takes so much energy that you’re not gonna do it accidentally with household materials.
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