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  • A young hospital porter in India is asked by a doctor to go get an oxygen mask, but

  • the porter doesn't quite catch that and instead walks into the room with an entire

  • oxygen tank.

  • This is no ordinary room; it's the domain of the Magnetic Resonance Imaging machine.

  • That magnet that does the magic in the appliance is not something to be messed with.

  • It's so powerful that the four-foot tank goes flying across the room at hyper-speed,

  • and unlucky for the porter and a technician, they're in its way.

  • Both of them get trapped for hours against the machine, all the time suffering incredible

  • pain from the force of the tank against them.

  • Twenty people pulling on a rope can't get that thing off.

  • It's only when someone deactivates the magnetic field that the two seriously injured men are

  • freed.

  • Ok, so after that very short true horror story you're probably thinking that it's not

  • such a good idea to walk about attached to a very powerful magnet.

  • Magneto from the X-men you are not, and so messing with magnets for ordinary folks like

  • you is something you might want to give a wide berth.

  • But what ifwhat if you somehow could attach a super-powerful magnet to you.

  • What exactly would happen?

  • Would bicycles start flying through the air and stick to you?

  • Would metal joints holding people's bones together burst through their flesh and adorn

  • your deadly contraption?

  • First, you need to know a thing or two about magnets.

  • You've all played around with harmless versions of them and we expect a few of you have some

  • stuck on your fridge right now holding up a message that's two weeks old.

  • Those things are weak to say the least.

  • Magnets are measured in Tesla and a fridge magnet only weighs in at 0.001 Tesla.

  • One of those horseshoe magnets they sometimes let you use in school might measure 0.005

  • Tesla.

  • Magnetometers are used to measure the strength of a magnet, but we prefer the name pull-tester.

  • You've all likely seen one of those junkyard magnets that can pull cars up.

  • They're about one Tesla, which isn't even that strong in the magnet world.

  • The junkyard magnets are called electromagnets by the way, which means their power depends

  • on the amount of electricity going through them.

  • You can also turn them off, which comes in handy when you want to put the car down.

  • Permanent magnets on the other hand don't require electricity.

  • They are what they are, like the ones stuck on your fridge.

  • Ok, so an MRI magnet could be anywhere from 1.5 and 3 Tesla, although the latest breakthrough

  • MRI magnetic is 12 Tesla.

  • Now that's a pretty strong magnet, but it's still not anywhere near the most powerful

  • magnet.

  • The strongest man-made magnet is 45.5 tesla, but even that's not close to the strongest

  • magnet out there.

  • Before we get ahead of ourselves let's look at the damage a small magnet could do.

  • Well, when we say small, we mean small in comparison to the giants but big in terms

  • of stuff you can buy onlineat your own risk.

  • Even if the magnet is fairly small, it might be meaty enough to cling very hard to some

  • metals, of which iron, nickel, and cobalt are a favorite.

  • So, if you're holding a magnet near some metal object you'd better make sure your

  • fingers or hand aren't in the way.

  • Trust us, we've seen this happen in videos with magnets only about a foot long and a

  • few inches wide and they wield some incredible power.

  • If someone's hand was caught between two large magnets, and by large we mean something

  • you could still hold in your hand, the force could completely destroy your hand.

  • There's no way any one human could prize those things apart.

  • Even so, large magnets you can hold in your hand aren't actually strong enough to make

  • things go flying through the air from a distance.

  • (you can get an idea of size of magnets in this video: https://www.youtube.com/watch?v=p0t0J_ERzHM)

  • As for the question, do regular magnets just by themselves cause humans any harm?- it's

  • thought they don't, but the jury is still out on that one.

  • Studies that we read say even if the magnetic field is very strong, the effect on the human

  • body is negligible.

  • That's only half of the story, anyway.

  • We'll soon come back to this quite frightening topic.

  • The strongest permanent magnets we humans make are called neodymium magnets.

  • Two large ones of these like we described earlier could potentially ruin a perfectly

  • good hand if they come together.

  • Still, even though one of them could quite easily be attached to your head, it's not

  • as if metal objects will fly through the air and stick to it.

  • You'd just look silly wearing your magnet.

  • Let's also just add this here before you get any bright ideas: these things should

  • only be handled by people who know what they're doing.

  • If you read the warnings about strong but small magnets, you'll see people are told

  • to keep them away from things like pacemakers or even mechanical watches.

  • These are not things you should be holding up to your grandpa's chest.

  • If a young child somehow managed to swallow two of them, even if they were tiny, they

  • could come together in the kid's intestines and cause a big mess.

  • This has actually caused death in the past.

  • Keep them away from your nose, too.

  • Early in 2020, an Australian astrophysicist was playing around with four very small magnets

  • and he ended up in the hospital.

  • He said he was bored during the lockdown and so decided to see what would happen if he

  • attached two small magnets to each nostril.

  • His intention was to try and create a device that warned people when they touched their

  • faces.

  • The inner two locked against the middle of his nose and that was that.

  • They were too strong for him to pull out and he got his day of fame in the media.

  • He said he even tried to use pliers to pull them out, but the pliers stuck to the magnet,

  • causing him some amount of pain.

  • He later said, “Needless to say I am not going to play with the magnets any more.”

  • We think it's now abundantly clear that magnets are not to be messed with, not even

  • the small ones.

  • Still, even if you stuck a brick-sized magnet to your head, the magnetic field wouldn't

  • make your toaster become a hat.

  • To get that kind of power you'd need something like the magnet in an MRI machine, but those

  • are electromagnets.

  • The MRI magnet is huge and it's powered by electricity so you just couldn't put

  • one on your head.

  • Theoretically, if you somehow could, you'd soon be taken out by the first metal objects

  • that entered your magnetic field, and maybe by a flying, shrieking family member.

  • One thing you could do with a very powerful magnet is levitate above it.

  • Frogs have actually been levitated on a magnet that was 16 Tesla.

  • The reason for the floating is the water molecules generate a magnetic field opposite to that

  • of the magnet, since water is what's called a diamagnet..

  • But floating is boring.

  • Now let's talk about destruction.

  • This brings us to something out of this world and to what we can call the big league of

  • magnets.

  • So down here on earth our strongest magnet is just above 45 Tesla, which as you know

  • in the right circumstances could cause someone to have a very bad day.

  • But what if we asked you what a billion Tesla could do?

  • We know we said magnets by themselves had a negligible effect on the human body, but

  • we were only talking about small magnetic forces.

  • It's a totally different picture when you bring in the big guns.

  • Ok, so you probably know what black holes are, but for everyone in the cheap seats,

  • here's a quick refresher.

  • In short, when a large enough star is on its last legs it explodes, and that rather cool

  • event is called a supernova.

  • This bright and beautiful thing happens because the star runs out of fuel and it collapses.

  • That can leave a black hole in its wake.

  • But then you've got some stars of a certain size and when they explode the outer parts

  • can blast away but a super dense mass is left in the middle.

  • These are called neutron stars.

  • When we say dense, we mean it.

  • Just a teaspoon of this stuff would weigh in the region of one billion tons.

  • If that's a bit hard to get your head around, you're not alone.

  • With gravity on a neutron star being about 2 billion times stronger than it is on Earth,

  • if one should ever wander into our solar system all hell would break loose.

  • It would cause cosmic chaos and Earth would hurtle off to another part of the universe.

  • There's a type of neutron star called magnetars and as you can probably guess, they pack a

  • magnetic punch.

  • Let's just imagine the moon was one of them.

  • If that were the case, you wouldn't be using your credit card again since they have magnetic

  • strips in them.

  • But that would be the least of your worries.

  • The credit card in fact would be in much better shape than you.

  • You can thank your lucky stars that no magnetars are close to our home turf, and by that, we

  • mean closer than 200 light-years away.

  • The thing is, every now and then massive seismic waves of energy erupt on them and they cause

  • starquakes.

  • When this happens, gamma rays spread out.

  • These have been recorded on our planet in 1979, 1998, and 2004.

  • No one was harmed, but the first time it happened the U.S. Department of Defense got a bit of

  • shock.

  • The last hit in 2004 destroyed some satellites and made changes to the earth's magnetic

  • field.

  • Ok, so the electrons in your body are magnetic.

  • That's nothing to worry about when we are talking about magnetic fields down here on

  • Earth, but a billion Tesla would literally rearrange a person.

  • If you were a few hundred miles from that magnetar all the spherical atoms in your body

  • would stretch out and start to look a bit like drinking straws.

  • This wouldn't bode well for you at all.

  • For a start, your nervous system would no longer function.

  • That's because the magnetism from this unpleasant star has messed with all the electrical charges

  • it takes to keep it running.

  • Atoms and molecules would no longer be working together in harmony.

  • How this would feel we can't exactly say, but it could be like being ripped apart.

  • After all, everything in you would be coming undone.

  • Suffice to say, you'd die very quickly, but you might just have enough time to see

  • parts of you twist and elongate, which is about as nightmarish as life could get.

  • What's interesting is if this could somehow be observed by someone far enough away sitting

  • inside a space station, it would look to them like you have stretched out, and then as the

  • star pulled you, you drifted towards it like a long streak of space pee.

  • The good news is the closest magnetar to us right now is tens of thousands of light-years

  • away and it's unlikely any will be appearing close to Earth soon.

  • We'll finish this with something a little different, but it's still a good warning

  • for all you magnet lovers.

  • For a while now folks over in the UK have been joining in a craze of buying strong magnets

  • and using them to look for hidden stuff in rivers and canals.

  • They just connect the magnet to some rope and then start trawling.

  • That all sounds innocent enough, but not when you hear that some people have pulled out

  • hand grenades.

  • In 2019, a grenade was fished out by a guy and the cops and bomb squad had to close off

  • the area for six hours while they dealt with it.

  • What's worrying is that thing could have easily gone off had the man mishandled it.

  • The guy seems to love his hobby, though, once proudly telling the media that he had a collection

  • of 13 guns that he'd found in the water.

  • Grenades are often found, but knives are about as common as fish in those murky British waters.

  • The hobby is fairly new, so we are talking about centuries of thrown away knives.

  • Mortar shells, safes from robberies and jewelry has been found in the past.

  • Probably the strangest thing pulled out happened in 2019.

  • A magnet found some metal that turned out to be handcuffs...and they were still connected

  • to a 22-year old man...He was dead, obviously.

  • Now you need to watch, “Why It Would Suck To Live Through The End Of The Universe.”

  • Or, have a look at, “What If You Only Drank Coke (Soda) and Nothing Else?”

A young hospital porter in India is asked by a doctor to go get an oxygen mask, but

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B1 magnet magnetic tesla magnetic field small strong

What If You Stuck a Really Powerful Magnet to Your Head?

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    林宜悉 posted on 2021/03/05
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