Tom de Castella bet that his petrol-fuelled old banger was cleaner than his dad's 2009 diesel. The test showed some new cars are worse than either.
We are not used to the idea of machines making ethical decisions, but the day when they will routinely do this - by themselves - is fast approaching.
Stillbirths are rarely spoken about. But insights from those who have navigated the heartbreaking experience can help parents come to terms with their grief.
7 days quiz: It's the weekly news quiz - have you been paying attention to what's been going on in the world over the past seven days?
The global and personal responses to the anti-sexual harassment campaign.
Deadly bomb attacks in Somalia kill at least 281 people but there are no hashtags of solidarity
Residents fed up with a two-hour drive to buy fuel decide to take matters into their own hands.
Grape the penguin became an online star after he "fell in love" with a cardboard cut-out in his enclosure.