The Lay ScientistScienceA challenge to homeopaths: how does one overdose?Homeopaths need to agree on what constitutes an overdose, and if they had an ounce of responsibility they'd be campaigning for better labels.You'll be shocked - shocked I tell you - to hear that I've noticed a bit of an inconsistency in homeopathic thinking. Well actually there are many, but one that's particularly worth mentioning is the disagreement over what exactly constitutes a dangerous overdose, because even if you believe in homeopathy, this should trouble you.

Reading American citiesBooksWinning in Las Vegas makes a good story, but losing sometimes makes an even better one. Here are our readers’ favourite books about Sin City Maile Chapman introduces the literature of Las Vegas “Half-meritocracy and half crap-shoot, Las Vegas is [...] the only city in America where the odds against you are all posted in plain sight, literally and metaphorically,” wrote Maile Chapman last week. Do read her blogpost about the essential Vegas literature – from Fear and Loathing to recent fiction about the struggles of life in the city beyond the Strip – but are there ever enough books in a list?

Calvin Harris onstage in Philadelphia, in 2015. Photograph: Gilbert Carrasquillo/Getty ImagesWith his new album, Funk Wav Bounces Vol 2, out next week, we take a look through the Scottish producer’s hit-studded career by Michael Cragg20. Scissor Sisters – Only the Horses (2012)Having met Jake Shears during sessions for Kylie Minogue’s 2010 album, Aphrodite, Harris was asked to do some extra knob-twiddling on this barnstorming single from the band’s Magic Hour album.

Lana Del ReyInterviewLana Del Rey: 'I wish I was dead already'Tim JonzeLana Del Rey has been through the wringer since her breakthrough success led to a vicious backlash, which shows in the 'narco swing' of her brooding new album Ultraviolence – and the fact that she can't stop talking about dying Alexis Petridis reviews Ultraviolence "I wish I was dead already," Lana Del Rey says, catching me off guard. She has been talking about the heroes she and her boyfriend share – Amy Winehouse and Kurt Cobain among them – when I point out that what links them is death and ask if she sees an early death as glamorous.

Portrait of the weekCultureMarie Antoinette Led to Her Execution, Jacques-Louis David (1793)· All articles in this series Artist: Jacques-Louis David (1748-1825) was not simply one of the crowd when he sketched Marie Antoinette on her way to the guillotine on October 16, 1793. David, an eminent Jacobin and ally of Robespierre, voted for her death. He was the Revolution's chief artist, costume designer, ritual planner. After knocking off this sketch, David had important business that day - a ceremony to unveil his icon of Revolutionary martyrdom, Marat Assassinated.