The lightsaber from Star Wars has to be one of the most recognisable -- and most loved -- objects from film and science fiction. Which is why it's all the more heartbreaking when science proves that we can't make one.
A super-heated beam of plasma contained within a forcefield it's a stunning weapon that almost everyone has pretended to own at some point. It's also technically impossible to make in real life.
For starters plasma is neither a gas, liquid or solid, it's a fourth state material that operates at 100 million degrees. That right there is your first hurdle.
The second is the fact that it's supposed to be focused using crystals. Well so far those crystals certainly haven't been found on Earth.
Finally, well actually watch the video above and our friends over at Discovery will give you the full -- and upsetting -- explanation including all the actually quite cool science behind it.