Invisibility cloaks, science or science fiction?

Ainissa Ramirez is a scientist, author and self-proclaimed science evangelist. She’s calling for big changes in science education and is a creator of podcast series called science underground. Hari Sreenivasan sits down with Ainissa to discuss one of her latest podcast episodes about invisibility cloaks.


Ainissa Ramirez is a scientist, author, and self-proclaimed science evangelist.

She's calling for big changes in science education and is a creator of a podcast series called Science Underground.

Here to discuss one of her latest podcast episodes about invisibility cloaks is Ainissa Ramirez.

All right.

With what you have on the table, I want to see how this works.

Well, I'm not going to be able to make anything invisible.

[ Laughs ]

But what I'm just doing is I'm using this paperweight as an object.


To show you how we can make something invisible.

Invisibility is actually just, we're fooling the eye, we're fooling the brain.

When I'm looking at an object, when you're looking at this subject, light's bouncing of that into our eye, and our eyes and our brains are smart enough to register that that's the object.

With you so far.

That's right.

However, if we can have light go around the object, we can't see it, and that's what they're doing with invisibility cloaks.

So you're bending the light that's hitting that object.

That's right.

So at least that it's not coming to our eye.

To our eye.

Yeah, you can think of light as a stream of water.

If water's moving this way and I'm over here, I have no idea that it went around this object because it looks straight.

So by going around the object, I can't see it.

So we have a gazillion lights on in the studio.


How would you possibly figure out a way to shield the light, all those lights that are bouncing into my eyeballs?

That's right.

So right now they're doing things in the laboratory, and in one group in Rochester, what they've done is they've used a series of lenses, and this is just a simple magnifying glass.

They're using high-tech lenses.

And they're putting them in certain positions, so what happens is the light is corralled, and then bent around the object.

And then they can make something as big as a hand invisible.


So that's pretty amazing.

The other thing you can do, is there's special materials that bend light differently, and we've seen this.

If you put a spoon into half a glass of water, you'll see that the spoon kind of looks big on the bottom and smaller at the top.

It has a different index of refraction.

So if you have materials that have different indices of refraction, they, too, can bend light around that object, so that you can't see it.

So it's still on a small scale, like I said, the size of your hand, and you can tile those things to make something a little bit bigger.

But it's not something you can purchase except for a kit that is available from Rochester, but...

So what do you get for 50 bucks if you buy this thing online?

What kind of -- I mean, it is not the Harry Potter cloak or the 'Lord of the Rings'' ring.

No. [ Chuckles ] No.

You're not going to be able to make a car go away, but what it is, is it's a set of these lenses and they're set at a certain distance apart.

That's very important.

So that what you're able to do is bend the light and then focus it around.

I mean, when I think about that, it's almost like the first people who looked through a telescope and figured out what those lenses were able to do, right?


And are we kind of there in an invisibility lens technology?

Kind of the very early stages where eventually now we take for granted this magnifying glass that you have.

That's right.

But it's a long time for people to figure out how to grind everything down and how to make this look what it is right now.

If you went back in time and you had this, you would be blowing people's minds.


I'd be creating fire with -- Wah!

That's right. That's right.

Yeah, but what's so interesting is light is a very old friend.

We've been studying it.

You know, Newton wrote a book about it.

Einstein showed that there were really funky things you can do with light.

And what we're doing is we're actually fulfilling what Einstein had predicted, that you can bend light in this way.

So, yeah, this is new.

You know, it's still at an experimental level, but, you know, it's happened.

It was something that was in science fiction and in fantasy, and now it's actually a possibility.

All right. Ainissa Ramirez talking about the possibilities of science and invisibility cloaks.

Thanks for joining us.

Thank you.