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ranger.com or just out by. Granger.

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For the ones who get it done.

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Can. You view around Solar Eclipse through

1:09

a square hole. Here's.

1:11

A cool way to watch the eclipse and

1:13

learn about the weird physics of lights while

1:15

you're at it. I. Read: Elaine.

1:18

If. You live in the Us and missed

1:20

the last total solar eclipse in two thousand

1:22

and seventeen. Good news. A. Total

1:24

Solar Eclipse is passing through Texas

1:26

and the Midwest states today. April

1:29

eighth: Remember. That in

1:31

a solar eclipse, the moon's shadow falls on

1:33

the earth. If you're in the

1:35

shadow it's going to look really weird

1:37

but also awesome. Even. If

1:39

you're not in the path of totality, you

1:41

can still see something. All of the continental

1:43

states will get at least a partial eclipse.

1:46

And does this even need to be said?

1:48

Never look at the sun without special glasses,

1:50

even when it's mostly blocked by the moon.

1:53

But. There's another way to view the

1:55

solar eclipse without glasses using a pinhole

1:57

projector. It's super simple to make

1:59

any. The to use all you need is something

2:01

flat like a piece of cardboard. Then.

2:03

You poke a hole in it with a pin. That's.

2:06

Pretty much it. When. Light from

2:08

the sun passes through the whole. It will

2:10

project an image on to some flat surface

2:12

like a sidewalk. If

2:14

you did this on a normal day, you'd

2:17

see a circular.of light. You. Might think

2:19

that's because the whole his rounds but during the

2:21

eclipse you will see a crescent shaped caused by

2:23

the moon passing in front of the sun. It's.

2:26

Both awesome and say for your eyes.

2:28

Actually, you don't even need to make

2:30

a pinhole viewer. They already exist all

2:32

around us. If. You stand under a

2:35

tree. The small spaces between the leaves will

2:37

act as pinholes to project a bunch of

2:39

little crescent images. Just for

2:41

fun, here's a question for you. Most.

2:43

Pin holes around because pins have cylindrical

2:45

shafts, but what if you replace the

2:48

circular whole with a square? What? What?

2:50

Say put around sun project onto the

2:52

ground. Would. Be a circle? Would

2:54

it a square? Or maybe it would be

2:57

a squirrel. What? About a triangular

2:59

whole. What? Would happen then. Try.

3:01

To guess. And. While you're thinking

3:03

about that, let's talk about pinholes. Consider

3:06

the absolute simplest case: a tiny circular

3:08

whole with a tiny red light. Since.

3:11

The whole is small. There's only one way for

3:13

the like to pass through. This means it will

3:15

hit a screen in a straight line from the

3:17

source and through the whole. Now. What

3:19

if we add a second light source?

3:22

Let's say it's green. Now.

3:24

We get to spots on the screen since

3:26

the green light can also passed through the

3:28

whole only one way. But. The

3:30

spots on the screen would be upside down

3:32

relative to the lights. You. Could

3:34

also add a bunch more lights in between

3:37

that would create a series of spots across

3:39

the screen. Now. Let's take

3:41

that idea to the extreme and replace the

3:43

lights with a continuous object Like a cat

3:45

were light reflecting off each point on the

3:47

cat would path through the tiny hole at

3:49

a different angle. Light. From the

3:51

top of the cat would make a spot at the bottom

3:53

of the screen. Light. From the bottom of

3:56

the cat was hit the top and likewise for

3:58

everything in between. Altogether, Get

4:00

an entire image of the cat upside down

4:02

on the screen. Yes, A

4:04

pinhole can create an image similar to

4:06

the way a camera does. There's one

4:08

big difference though. The cat image

4:10

will be very dim. Because.

4:12

The whole is so tiny it only let's

4:15

a small amount of light through a camera.

4:17

Gets around that by using a larger aperture

4:19

with a lens to focus the image on

4:21

the screen, the film or sensor. Which.

4:24

Actually could use the simple set up to make

4:26

a pinhole camera. It's a real thing. But.

4:28

What about holes that are not tiny and not round?

4:31

When. The whole is larger than a pin

4:33

pricks. It gets complicated. But. We can

4:36

approximate the effect by using lots of little

4:38

pin holes close together. Let's. Start

4:40

with two tiny holes. Now.

4:42

There are two paths of light from the

4:44

source to make it to the screen. That

4:46

means there are two spots adding the greenlight.

4:49

Both lights make two spots. Now.

4:51

Let's say there's a bunch of tiny

4:53

holes arranged in a grid to approximate

4:55

a square hole. Of course, the more

4:57

holes you use, the closer A will

4:59

be to an actual square hole. Let's.

5:02

Use twenty five holes arranged any five

5:04

millimeter wide grid so each light will

5:06

make twenty five spots on the screen.

5:09

Each. Light source would cast a square image

5:11

onto the screen. That. Sort of

5:13

what you'd expect. A square hole makes

5:15

a square image. But. Let's stop and

5:17

think about that. This. Would

5:19

actually be an upside down image of

5:22

the object, which instead of a cat

5:24

is a pair of lights six centimeters

5:26

apart. And the two parts of the

5:28

image are made of squares. How.

5:30

About another example, What if we use

5:32

a circular light like a ring of

5:35

lights around the Total Eclipse passing through

5:37

a triangular whole? Again,

5:39

If the screen is next to the whole, you get the

5:41

shape of the whole a triangle. If. It's

5:43

farther away you get the shape of the

5:46

light source, a circle. So. The

5:48

shape of both the light source and the

5:50

whole do indeed matter. When. The screen

5:52

as close to the whole. it's a triangle made

5:54

up of circles. When. It's far from

5:56

the whole. It's. A circle made of

5:58

triangles. That. just cool. Thanks

6:02

for listening to Wired. My name is Zeke Robinson

6:04

and for more stories like this one visit us

6:06

at wired.com. Spoken

6:13

Lair. Without

6:17

the ones like you who work tirelessly

6:19

to keep things running everything would suddenly

6:21

stop. Hospitals, factories, schools,

6:23

and power plants, they all depend

6:25

on you. No matter the weather,

6:27

emergency, or time of day, you're

6:30

the ones who get it done.

6:32

At Grainger, we're here for you

6:34

with professional-grade industrial supplies. Count on

6:36

real-time product availability and fast delivery.

6:38

Call, click grainger.com, or just stop

6:40

by. Grainger, for the

6:42

ones who get it done.