When or why are magnets safe to use now?
In: Technology
Hard disk drives (HDDs) encode information with tiny magnetic fields on a disk. Those need to be changed regularly to update information. If information is changed improperly, it can cause errors and damage that information. A sufficiently strong magnet can even damage the disk enough that the needle that reads it can be pushed out of place and be unable to read data or scratch the disks.
Solid state drives (SSDs) encode information in a fundamentally different way. Basically, nothing needs to move, and there’s no magnetic fields involved, so it can’t be damaged by a magnet.
Cathode ray tube televisions (CRTs) use an electromagnet to steer a beam of electron to hit phosphors on on the screen at the right time so the right colors glow at the right time, creating an image with the right shapes and colors.
Distorting that beam distorts that image, and damaging the electromagnet or any phosphors on the screen can permanently damage the CRT’s ability to make the image.
Information is also not commonly stored on magnetic tape anymore (audio tapes, video tapes). Magnetic tape works similarly to an HDD (although it is usually analog data rather than digital) and a magnet can damage or erase that data. Tape erasers literally just drag the tape across a magnet.
The magnetic strips on credit cards aren’t designed to be rewritten, so they more easily resist a magnet’s influence
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