Kind: captions
Language: en
We have that card with a little round
hole in it. And what I want you to do is
hold it up u and try to cast a shadow on
that wall there.
And I want you before you do it to
predict what we're going to see.
Shadow of the card.
With a little hole in it.
We will see that figure enlarged on the
wall.
It's not very pronounced, but you can
actually do see the little hole in it.
And of course me.
So cool. Woohoo. My next question for
you is we have this card. [snorts]
What's that like? It's bigger hole.
Can you tell me what size circle we're
going to see?
Like compared to the other one.
Bigger.
Like twice the size maybe.
But still the card with the larger round
hole.
What do you see?
Bigger hole.
The card and the hole is slightly bigger
than the previous one.
They're the same thing just larger.
Okay. What I want you to do
the same size though.
It's approximately the same size as the
last one.
Why don't we compare it? Here you go.
You're right. It is. One's just fainter
than the other.
Oh goodness. It actually looks about the
same.
Same size hole.
I can't believe that. It's must be the
sun playing tricks with my mind.
[laughter]
What about here's really going to test
you? Right.
Okay.
Uh tell me about what's on that card.
It's before you put it up.
It's a triangle.
Yeah.
Okay. So
So what do you expect that we'll see on
the wall?
A triangle, but I wouldn't be surprised
if it was a circle. [laughter]
What are we going to see?
A triangle.
I'm certain.
Okay, let's have a look. Oh wow, that's
awkward for me.
It's a circle.
It'll be a triangle.
Well, we're not going to see a triangle.
Why not? [laughter]
Cuz everything else has been a circle,
so it'll be a circle.
I'm sticking to triangle.
Okay, it's a circle.
Let's have a look. Now I'm interested.
Well, there you go. It's a circle.
Do you want to compare it to the one of
the others? I'll give you the bigger
one. The bigger one. The bigger one.
Oh my goodness. I really like this
project. I'm learning something. The sun
is definitely playing tricks in my mind.
The sun is deceptive.
That's weird.
Why Why are we seeing circles with all
these cards regardless of the shape of
the hole?
I really don't know. I'd like to know.
When you take away the definition from
any kind of shape, it ends up being just
round to our eyes.
There, for example, you get a perfect
triangle.
But it was a pretty decent circle from
back.
So, it must you must get to a certain
size here. It doesn't matter what what
shape it is. It's just turned back
probably.
Why is it going to a circle though?
When you look at the sun, it looks sort
of round, doesn't it? So, I'm not sure
if that's got anything to do with it.
Well, the light is going through these
little holes and it is the sun. The sun
rays just sort of um going through those
little holes making circle of the sun. I
don't know. You tell me.
Exactly. You nailed it. What we're
looking at there is actually an image of
the sun.
Really?
Yeah.
Oh, wow.
The earth's round and the sun's round.
Yeah. The [laughter] sun the sun's
round. I guess
the building's round.
The building's round, is it? No, the
building's not round.
So, what we're seeing is
a projection of the sun.
I've never thought about it before.
I think that you actually know. And I
think you have actually thought about it
[laughter] before, but I think you're
not queuing that right part of your
brain that knows the answer.
Yeah, probably.
There's a part of your brain that knows
the answer.
Well, I did photography at school. Um,
and we did pinhole cameras. The hole
actually reflects what it's showing
on the wall. So what?
So you see what you see on the other
side.
So what's that?
So it's the sun.
Well, there you go. I've [laughter]
learned something today, Derek.