Although it sounds like something straight out of a Hollywood sci-fi blockbuster, claims that time travel is a reality have persisted for decades. From a 17th-century painting featuring a "Sputnik" satellite to an eagle-eyed audience member holding a smartphone at Elvis Presley's final concert, history is littered with baffling anomalies.Here, we take a look at the most mysterious evidence that really does make us wonder if intrepid folk have mastered the fourth dimension, including a 1,500-year-old mummy rocking Adidas trainers and a Native American taking a "selfie" in 1937.If that's not enough to make you query the space-time continuum, wait…