And the London faces the prospect of a 300 million pound pollution penalty every year

from Europe over bad air and that's largely from traffic in our

capital. Engineers say part of the solution lies with electric transport so

this week we're getting under the hoods of a new generation of vehicles

ranging from the first electric buses to tomorrow's

supercars. Plus news about how scientists are making objects levitate in the

lab with sound and why there are now three types of type

two diabetes. I'm Chris Smith and I'm Greer Jackson and we're the Naked Scientists.

The Naked Scientists Podcast is powered by UKfast.co.uk.

If you don't know what a tractor beam is, then you possibly didn't watch enough Star Trek,

but for the uninitiated, this is a way of manipulating objects at a distance,

and Bristol University's Bruce Drinkwater has managed to do it using patterns of sound

waves, which he fashions into a Sonic cage in the air that can trap things.

And if you move the Sonic cage, then whatever's inside it moves with it.

The discovery could make a big difference to the way that we practice medicine.

We've made the world's first fully functional tractor beam, and for it to be a tractor beam it's got to be

able to grab an object from one side so it means there's got to be a source of the

energy in our case sound waves it's got to travel out it's got to grab the object

and we've got to be able to pull that object back towards the source.

Talk us through the experimental approach then.

What do you do and how does it work?

So can imagine in front of you an array of lots of little loudspeakers.

...