Hey everyone today I'm going to be showing you my magnetic accelerator ring
launcher now watch this now before I show you how awesome this is and how
fast we can accelerate pieces of metal instantly let me explain how it works
when an electron moves through space it creates a changing electric field
obviously because as the electrons moving it has a field around it and that
field follows the electron but as an electron moves through space a changing
electric field also creates a magnetic field so what that means is if you move
an electron you create a magnetic field so I have two wires here the electrons
are going to travel down the black wire turn around and come back this direction
so the directions of the electrons and both wires are opposite in this wire
it's going this way and in the red wire it's going this way so I have just these
wires hanging here and you can see about how close they are together but now
watch what happens when I flow a current through them three two one now look how
far apart they are and then stop the current and they go back together and
then if I pull sit I can really get these swinging so what's happening here
is as the current moves through these wires is creating a magnetic field and
the way you can tell which way the magnetic field is going is if you point
in the direction of the current your fingers will point in the direction of
the magnetic field so it's going to curve around this wire in this direction
it's going to come around like this and in this wire the currents going the
opposite direction so you're going to have the magnetic field pointing the
opposite direction so it's going to go like this so because you have these two
magnetic fields pointing in the opposite direction that means that they're
actually going to repel each other now in this case the magnetic field was kind
of coiled around it in a cylindrical shape but what if we wanted a more
traditional shape of a magnet with a true north and south pole well then we
just coil our wires instead for example let me just take my wire and coil it
around this so see how this can't pick it up at all
right now but then when I connect the wire now it can then release it and it
drops so we've shown that if you have moving electrons or a changing electric
field you can create a magnetic field and what's interesting is the reverse of
that is also true if you have a changing magnetic field you can create an
electric field or an electric potential for example you can see that I just
wrapped a bunch of wire around this paper towel roll here and here's my two
ends connected to a voltmeter here so let's look at the voltage as I move a
magnet by this coil of wire here so notice how if I just set the magnet here
there's no voltage whatsoever it has to be moving so when I move the magnet it
creates a voltage on the wires but what's interesting about this is when I
move the magnet past the coil of wire it creates a voltage and that voltage
pushes electrons in the wire but we know that when you have electrons moving in a
wire it creates its own magnetic field but the only thing is the magnetic field
is going to be pointing the opposite direction of the magnet that caused it
all so that means that when I move the magnet past this coil of wire I kind of
feel a resistance and that's because I'm causing electrons to move in there which
create a magnetic field which push back on the magnet and you can see this a
little bit clearer if I just replace this coil of wire with a flat piece of
metal you'll notice that aluminum by itself is not magnetic at all aluminum
has no ferromagnetic properties it doesn't stick to a magnet and just for
reference this is what it looks like when it slides off something pretty
predictable right but watch what happens when I try to slide it off this magnet
it's almost as though a sticks to the corners it doesn't want to move fast
past them it's pretty cool that's because as the electrons in the metal
move past the magnetic field in the magnet it causes the electrons to move
around in circles tiny little circles that are called eddy currents and those
anti currents create a magnetic field of their own that opposes this magnetic
field and so basically it creates small little electromagnets in this piece of
metal that oppose the force of whatever it's doing so whatever way you try to
move it it creates a force that opposes that and this is called Lenz's law and
you notice that the reason that it doesn't more on the corners is because
this is the region of the highest changing magnetic field and that's the
place where it gets caught up the most because that's the place of the highest
changing magnetic field and you can see that when I cut little slots in it so I
make it so that they can't form little loops of electricity it doesn't get
caught up on the corners as much so basically it's not allowing eddy
currents to form anymore in the middle and so what happens when you have a
changing magnetic field near a piece of metal that piece of metal will oppose
the magnetic field that induced the current that made the magnetic field in
the first place and so what I have here is just a coil of wire wrapped around an
iron core and this is connected to my AC voltage and so it's creating a changing
magnetic field because the electrons are going back and forth and back and forth
60 times per second so now watch what happens when I stick a piece of metal by
this changing magnetic field three-two-one so let's give ourself a
little more room and see how high this goes three two one oh that was awesome
so this is just a piece of aluminum you can see here's an iron nail and my
aluminum it's not magnetic at all so the only thing that's causing it to fly up
is the eddy currents created inside of it and those eddy currents create a
magnetic field that opposes the change magnetic field that's causing the eddy
currents and so it pushes it away from it and I can prove that it's the eddy
currents moving around in a circle that's causing a magnetic field to
oppose this one and that's the reason it's flying away for example here's a
complete ring and here's a ring with a slit in it so it's not a complete
circuit now you can see nothing happens now remember the strength of the
magnetic field that's induced in this aluminium cylinder here is dependent on
the current that's flowing through it one way that I can reduce the resistance
and increase the current through it is to reduce the temperature because as
temperatures go down resistance goes down so if I put this in liquid nitrogen
I should be able to get it to go a lot higher than I could at room temperature
let's try it so here it is at room temperature
now here there's a liquid nitrogen temperatures whoa awesome now watch this
so the energy from my AC wires here are going into launching the ring now if I
don't give that energy anywhere to go it has to go into heat for example if I
don't let this launch if I just hold it in place
watch what happens okay got a hold a little tighter
look at that instantly heat up watch so you can see when I stick to magnets on
here how the magnetic field of this is going to alternate see how it spins it
one two three jump hey everyone thanks for watching another episode of the
action lab I hope you enjoyed it if you did don't forget to subscribe if you
haven't subscribed yet and thanks for watching and I'll see you next time