Hi, we're here from Curiosity.com to help you get smarter in just a few minutes.

I'm Cody Gough.

And I'm Ashley Hamer.

Today you learn about a new laser that uses sound instead of light,

a counterintuitive trick to get your kids to eat vegetables,

and a cognitive bias that explains why most people think they're better than other people.

Let's satisfy some curiosity.

You're probably familiar with optical lasers or lasers that use light, but have you ever heard of a laser made from sound waves?

This new so-called phonon laser exists, and as reported by the conversation conversation we could find uses for it in

communication and sensing like finding the mass of very small molecules.

Let's back up though and first get into what makes an optical laser light special.

While the light from a light bulb or the sun goes in every direction,

the light from an optical laser is concentrated into a powerful beam, with the light waves emerging from it

moving in the same direction in step with each other.

Since we can focus waves of light, it makes sense that we can focus waves of sound. I mean, after all, they're both made of waves, right?

And scientists have done just that. The result is a phonon laser,

where the oscillations of light waves are replaced by the vibrations of tiny solid particles, each about 100 nanometers in diameter that are perfectly synchronized.

To create this laser, scientists started by levitating the

nanoparticles using an optical tweezer. That's a laser beam that traps a

nanoparticle in mid-air, like a tractor beam in Star Wars. The nanoparticle doesn't stay still. Instead, it swings

back and forth like a pendulum along the direction of the trapping beam. When

they levitate the nanoparticle, scientists are isolating it from the environment around it,

...