Which inventions might exist in 30 years from now?

Today, 21 October 2015 is Back to the Future Day.

It's the exact date that Marty McFly and Doc Brown arrive in the future, in the second 'Back to the Future' film, released in 1989.

The movie imagined a 2015 with hoverboards, flying cars and self-tying shoes.

But what inventions will exist in 30 years from now?

We asked technology journalist Chris Baraniuk for his thoughts.