Futurama loves to play with time travel, even at the expense of making any sense. Tonight Fry and company travelled ever further in time to discover a backwards time machine. It'll make sense if you watch the clip.
[There was a video here]
Breaking with Canon Alert!: In a past episode, time itself was said to be a "straight line", and this episode confirms that our universe operates cyclically. So just ponder that one for a while, Stephen Hawking.