Everyone knows that not all marriages survive, but how do you know if yours if the one that’s going to survive? Reuters reports on newly-wed Londoners, Alanna and Mike Clear, who’re literally going the distance to see if their marriage works. The couple are going on a 20,000-mile trip on a motorcycle with a sidecar and plan to ask people from Alaska to South America about their relationships for a documentary called, not surprisingly, ‘Going the Distance’. The couple is also getting some help from modern science. Biological anthropologist, Reuters says, Helen Fisher and neuroscientist Lucy Brown of Rutgers University, New York, have scanned their brains to see if neurological responses showed they were in love. A DNA-based dating service (scientificmatch.com) has also taken DNA samples to check on whether they’re genetically compatible. A relationship therapist (yes, that’s what the story says) has spent a day analysing how they interact. Given their time on the road and their needs, the couple asked friends to forget the china and instead buy brake cables or nights in hotels as wedding presents. You’d think the long ride together would help them decide if they’re compatible, but the couple plans to open an envelope containing the results of the three tests — if the experts think they’ll last, they’ll renew their wedding vows. If they don’t? “We’ll try to brush it off, but I think it will niggle,” Mike told the newswire.