Kind: captions
Language: en
So, uh, Nigel, what have we got here?
We've got something called a fire
syringe. And what does it do?
Oh, well, I'll show you what it does.
Some cotton wool in there.
Okay,
I'm just going to compress the air in
it, and hopefully it will I don't know
what it's going to do.
Wow,
that's pretty cool.
You made a spark in there. Was there any
source of fire, like a match or anything
down there?
Well, as you can see, it's pretty
transparent. There was no match in
there. Um it was actually just the
compression of the air on top of it um
which was able to ignite the um the
cotton wall that we had in there.
So you're saying if we compress air we
can make it hot enough to ignite cotton.
Yeah. By because air is made up of
particles. So when you're actually
compressing it you're forcing those
particles to collide closer together
which is actually going to raise the
temperature of in the inside of that
tube there. Okay. Can you describe the
apparatus for me? Well, all there is is
there's a glass chamber in there where
the cotton wall sits. And as you can
see, there's this piston that moves up
and down into that glass chamber. And as
it moves up and down, you can actually
compress the air.
So, it's like a little plunger.
Like like a little plunger. Yeah.
Okay. So, uh why don't we set one up uh
so we can do it again?
Do it again. Okay. I'll clean the
remnants out. What are the tricks here?
Uh the trick is to get not too much but
not too little cotton wool. And it's
good to get it airrated so that there's
a lot of air around it so it makes it
much easy to um ignite just like a good
fire.
Is it just me or do you feel like we're
on a cooking show?
I feel like we're on a cooking show.
Yes.
Who do you think would be Jamie Oliver
in this situation? Would it be you or
me?
I'm more manly. So
he's more like Nigella Lawson, let's
face it.
That's a good play on words.
I wish.
All right, we're ready for this.
Yes. Simple as that. Obviously, no
matches, no switches, no anything. Okay.
Um, we'll try it
again.
You want me to try?
You can try it. Do you have the
strength?
We're going to find out.
We'll find out. This is going to be
awkward, Derek, I think.
Okay. So, what I'm going to try to do is
compress the air in there. And uh, by
compressing it, I'm going to increase
its temperature cuz we're pushing all
these air molecules together. And if I
get it hot enough to the ignition point
of cotton, hopefully cotton will catch
on fire.
Yeah. I've heard that the um auto
ignition temperature of of cotton is
about 400° C. So you can get quite quite
enormous amounts of temperature from a
very quick compression. 3 2 1.
Oh,
surprise.
Beginner's luck.
Yeah, check that out. So I guess we
could generalize and say if you do the
compression quite slowly then well
there's time for the heat to escape out
of the air and so we don't actually get
a high high enough temperature to cause
the cotton to ignite.
Yeah. And there's actually a word for
that. It's called an adiabatic
compression. That's the one where
there's enough heat generated quickly
enough so that we can get that auto
ignition.
Yeah. So, an adiabatic compression would
be one in which the heat doesn't escape
from the gas.
Doesn't have the time to.
Absolutely.
Yeah.
All right. Well, let's go see if we can
auto ignite some other things.
Yeah. Maybe some hair. Okay.
Maybe not a good fuel source.