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 if…what 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 online – at 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?”