"If a man can walk 3 miles in an hour, and then discovers he can travel faster, is this a bit like time travel?
Say the basis for making a journey is walking speed, and this is world wide. Then someone creates a device or machine that can make the journey more quickly isn't this a form of travelling through time into the future?
If you imagine a car is a time machine - through the rear windscreen is the past, through the front windscreen is the future and in the car is the present. Through the side windows is the present as it happens in all across the universe.