10 Biggest Unsolved Mysteries In Science

7. What Causes Cancer?

If you believe the papers, you'd probably come to the conclusion that everything causes cancer, but the reality is that we just don't know.

We know how cancer occurs. Random genetic mutations occur in the cells, causing a runaway duplication effect and leading to a tumour, but experts have so far failed to agree on why this happens. In a controversial study in Science magazine, researchers took all of the research and evidence related to the causes of cancer, and were pretty much forced to conclude that it's largely down to luck.

We all know, for example, that smoking can give you lung cancer, but how is it that some people can smoke for their whole lives and remain cancer free? The chance of getting lung cancer as a smoker is 18 times higher in smokers, but not all smokers will get it, and not all non-smokers are safe, so it doesn't cause it in the same way that pushing a ball down a hill will cause it to move.

It's not exactly solid cause-and-effect stuff.

Figuring this out is arguably a priority for this generation, but at the moment it's practically a case of "well something's gotta get you."