Hello and welcome to Beals Science, I'm Craig Beals and I've got a plasma ball out
today because I like to do a bunch of activities with my students revolving
around a plasma ball but really teaching the concepts about electricity about
capacitors and really making science exciting. And I want to share those with
you today, so stick around while we have a little fun with electricity on Beals
Science! Well, how does a plasma globe work? At the center of the globe is a
high voltage electrode that has a very strong alternating voltage. Then there's
a gas surrounding it. Now that the alternating voltage at the center
creates electromagnetic waves that course through the glass toward the
outside of the globe. We're going to see if we can concentrate the area where the
electrons are hanging out by building a simple capacitor out of pennies. Right
now that copper is building up with electrons, it's building up with
electricity, but watch this we should see it arc across to my finger.
See that? I'm gonna grab a penny and you'll see it even better.
Watch this!
The kids are here helping me out today and they heard me squealing about my burned
finger. Uh yeah! Don't play with electricity kids! When I
get out the plasma ball and teach about electricity I like to spice it up a
little bit and throw in some stories a little bit of science magic. And one of
the stories that I love to share with my students is the story that before I was
a teacher I was actually a Jedi which none of it, of course, is true and at this
point my students roll their eyes at me. And here's what would happen when your a
Jedi. Every morning you'd wake up and you'd have to fill your lightsaber with
the force so that you could go and fight the dark side. We would go take our lightsaber
*struggling* and pull the force...so that we...could fight...the dark side with our light! And at the
end of the day, after you get done, you've gone out and fought the dark side
you got to put the force back in to let it can replenish itself and be ready for
you the next time.
Oh that's magic people! Actually it's not. It's science! Because you can see part of
the problem, the reason that maybe wasn't such a successful Jedi, is that as soon
as I walked away from the plasma ball or "the force" my lightsaber no longer work
and of course the other thing you're starting to figure out right about now
is that's not a lightsaber - it's a fluorescent light out of the
ceiling! But, that doesn't make it any less cool this! This is the same concept that
we have with the pennies when they were stacked up there because we know we've
got these electrons - this electrical field that's formed around the outside
of this - the way we can prove that, of course, is with the pennies that we just
did but also with this tube of gas! You see, a fluorescent light works because
electrons flow through the gas in the tube, they get excited and they light up.
Just like what we see happening inside of this plasma ball. So all I have to do is
get this close to the plasma ball and it starts to glow!
Well, why does it stop wherever my hands are? Well, because my hands are a
good path for electrons to get to the ground, to get to the earth, and the earth
can hold a lot of electrons. So it's just an easy place for them to go.
I'm gonna make a plasma ball, sort of, using this high-powered Tesla coil. It's
used for checking welds and things like that and just a regular old incandescent
light bulb. Don't try this at home! It just gets you in trouble, me in trouble,
and potentially get you hurt! This is gonna be hard to see but if you look at
the very end of that thing you can see purple. It's ionizing the air out here!
It's actually turning the air into a plasma! You can *smells* you can smell it. It's
making ozone as that high-voltage electricity flows through the air like a
lightning bolt...in my hand! We've got a helper in the lab today this is my
daughter and she's gonna shock me with this high voltage Tesla coil and
what I'm gonna do is I'm gonna take that light bulb that we talked about before.
And electricity should flow up through here, inside the gases, and up
through my hand, but it'll flow around the outside of my hand, and this
thing is going to look just like our plasma ball! *surprised* Okay, there you go!
Do it again! That's the same thing that we saw with the plasma ball right?!
Let's put all those pieces together. I'm going to turn myself into a human
lightning rod and I'm gonna need them both to assist me. What do you think mom's gonna
say?... Get a life? Oh, "stay alive"... stay alive. Should we try this at home? Tell them. [Kids] No!
No! No not safe! Don't try it at home. But, we're gonna try it here at school...yeah!
It's not at home kids, this is a school of learning, this is a science classroom!
This is where we learn and inspired! [Girl] But should we turn off the cameras? [Craig] Are they
still on? [Girl] Yes! [Craig] That's awkward! This was a terrible idea from the beginning but
we'll be perfectly fine because I've done this many, many times in many venues!
I've even done this on television for the news, the local news station, and
nobody got hurt! Yep! So here we go! Instead of me holding
on to this, I'm gonna put this end on my tongue and then I'm gonna hold that end
over there and the electricity is gonna flow through my body - around my body -
through my face - around my face - across my tongue over there into his hand and
into the ground!
[Boy] *nervous* It's going to go through my body?!
Kill the lights! Here we go! I'm gonna put it on my tongue, when I making noise
you're gonna have to put the juice to that! You ready? On three...One...Two...Three!
AHHHHHH! OHHHHHH! *Laughing* You can see the light in
my face? In three, two, one...*screaming* AAAAAHHHHHHHH!!
*cheering* We did it!!!
Kids I survived being a human lightning rod. How did we do? Thank you for
your help. And like we always say here at Beals Science, the kids asked if they
could help me say this part - what do we say at the end of every little Beals
Science video guys? KEEP ON LEARNING! Yeah, and thanks for watching!
Good job guys, thanks! !gain don't play with electricity at home if
you want to see just how horrifying it is when you get hit with high-voltage
electricity I got shot with a police taser for science, made a video of it, the
description's down there, check it out if you really want to know why you
shouldn't play with electricity at home!