Did I destroy my friend's TV with a magnet? (2022)
fleet.org.au
fleet.org.au
Some family was over visiting and the adults were sitting in the adjoining dining room with us kids in the living room by the TV.
Lightning struck somewhere close by and a tennis sized ball of electricity entered the dining room through the outside wall. It crossed the room in about a second, went through the wall to enter the living room and then accelerated towards the TV.
When it hit the TV box the TV went out and the house lights flickered for a bit, but everything seemed fine. We turned the TV back on and it had a big purple corner which the degauss function couldn't fix.
Overall it probably lasted about a week before the effect faded enough that it was no longer visible.
It's telling that the Wikipedia article only lists once occurrence where scientists think they might have seen it, and devotes several paragraphs to it.
I’m not going to say it’s definitively wrong, but when people are reporting it all over the place, and there’s only one scientific paper from years ago that says they might have seen it on the other side of the world a decade ago, it’s hard for me to take it as solid evidence that it exists.
We even had a bunch of math saying they weren’t possible/probable! (Ex once in an 100M years or so) so they were quite sure of themselves.
The we started to get large scale buoy data and sure enough, rouge waves! (the math was wrong).
Our understanding of earth phenomenon is far from complete. For lightning, red spites/green ghosts/etc are all relatively new discoveries.
I’m not questioning gp’s credibility, because I also found myself in impossible situations like kitchen pot overheating and exploding dramatically, which supposedly should only happen in controlled lab circumstances. But I understand when people can’t believe.
Added: we also should look for easier explanations, especially when it comes to early memories. Kid’s imagination is a powerful thing.
Ball lightning supposedly occurs in places where there’s recording equipment everywhere, and people all over the place claim to have seen it. Yet we don’t have any evidence for it yet.
A magnet might temporarily mess up the magnetic convergence with magnetised spot areas, but that should be fixed on next switch-on.
The Earth’s magnetic field can also affect the picture
That's because when the convergence controls are set correctly, they also take care of the magnetic field of the earth too at the same time. If you turn the TV upside down, you would also have to reset the convergence controls. No biggie, but it is something that needs doing.
My dad (at the time a technician maintaining TV transmitters) finally fixed it by power cycling it a few dozen times.
He told me that if he hadn't known how it works I'd have had the hiding of my life...
A large enough magnet (or other trauma) can permanently warp the mask or grille --- this is basically unrepairable. The degauss system should undo magnetism eventually, but sometimes it takes several activations.
The earth's magnetic field definitely affects Cathode Ray Tubes and many other things.
High end CRT computer monitors came with a built in degaussing system and some had controls for aligning the R,G & B electron beams.
https://en.wikipedia.org/wiki/Degaussing https://hackaday.com/2016/05/25/wtf-is-degaussing/
From personal experience, I took a 20" Sony Trinitron from Los Angeles to New Zealand in the mid 90's. the reversal in the Earth's magnetic field between the northern and southern hemisphere's meant I could never completely get the RGB guns to line up correctly.
Check out my previous comment on the time a friend and I watch his TV upside down. There was zero difference that I remember.
Consider where most of the monitors are shipped from. Did they send "southern hemisphere" specific televisions and crt monitors? And what happens at the equator?
Could your monitor have been fritzed on the flight? Did it work normally when you brought it back?
This would actually be a fantastic YouTube video, whether it debunks or proves the claim being equally interesting.
But who knows, maybe a solar flair hit you between rooms and changed the environment enough to disrupt the tv, but then i'd bet it'd effect all the machines. Eh, who knows. Weird thing that electromagnetism
One night David Letterman did an episode where throughout the show, the camera(s) did a full 360 degree revolution.
When the show was half-way through, it was of course, upside down. So we turned the television upside down.
I personally don't remember anything unusual about the way the show appeared, other than that the TV was upside down, and then on its side for a few minutes at the 45 minute mark.
If he responds within a reasonable time, I'll follow up to mention if he remembers this the same way I do.
Likewise, remember the green swooping radar of days gone by? In wartime, those regularly got a wild ride through gravity, and yet you never hear of them having a problem with it.
I'm really thinking this article's "throw-away" comment is really worth throwing away.
Monochrome CRTs don't have a shadow mask or an aperture grille, and no degausing or need for it. Certainly, magnetic fields will interact with the electron beam of a monochrome CRT, but if it's the earth's magnetic field, it will be uniform over the whole screen, and not a big deal.
Moreover, there were also dark-trace CRTs or Skiatrons (developed just before WWII and used for Radar during the war), producing a dark-on-light image, which were also based on the secondary emission, rather than the primary one. (Technically, this was based on the displacement of free electrons in an alkali-halide crystal lattice, which made the CRT locally opaque.)
They had it fixed though: a guy came out from the shop with a hand-held degaussing tool and it was just fine afterwards.
I was calmly informed that he'd already selected a watch that was immune to magnetic fields. But of course that was a real danger to old-fashioned movements which had many ferrous parts that relied on not sticking together.
I never lived it down. Some of our childish rebellions are ridiculous in retrospect!
That's incorrect: there aren't many CRTs in a TV or monitor. There's just one in monochrome displays or three in color displays. That paragraph even seems to imply that there is one CRT per dot. I don't think you would even need magnets to guide electrons (much less one set of magnets for all the CRTs): just aim each CRT at the correct location. Seems a weird misconception from someone who calls themselves a physicist.
> For example, LED TV use individual LEDs to switch on and off to construct a picture.
Nope.
Unless they're talking about microLED TVs, which is almost certainly not the case.
the CRT is the giant glass picture tube, cathode ray tube, there is only one of those in a TV.
For color TV there are 3 "guns" shooting electrons at the different colored phosphors. There is a single system to guide all three electron beams to their respective right parts of the display.
http://www.learnersplanet.com/sites/all/sites/default/files/...
Is it the phosphor coating? The deflecting coils? Some sort of static field in the glass?
There was a time with some of these larger TVs and monitors where a coil was built into the frame and would energize briefly on power up, or with the push of a button on the control panel.
I know a magnetic field was being retained somewhere, just wasn't sure which component it was.
Worse, a strong magnet (especially a modern rare-earth magnet) can bend the shadow mask, causing color distortion which can't be corrected by degaussing.
Was fun to understand the election beam was being deflected a magnetic field at the time tho
Um...