Wesley Clark's Excellent Adventure
The recent TCS article on De Rebus Bellicis is obvious evidence of time travel. We have a fourth-century treatise with ideas on weapons and tactics that seem like ordinary common sense today (e.g., paddle-wheel ships) but don't fit in late antiquity at all. We also have a professional military officer who gives advice to the world's only superpower and who's also interested in time travel. Coincidence?