However, other more reasonable space-times that are allowed by general relativity and which permit travel into the past have since been found.
She also wore a "transit suit" permitting travel through hyperspace.
In addition, Continental has a program permitting virtually unlimited travel - one trip a week - for a specified period.
These cards do not generally permit international travel, but some neighboring countries have agreements.
Last of all, man invented the anti-accelerator drive which permitted galactic travel.
The Government permits free travel throughout the country, but travelers must stay in the hotel or private residence that they listed on their visa application.
The dam's lock system permits travel of recreational and commercial vessels from the river to the harbor year round.
A few categories of citizens were permitted relatively free travel.
Since the Government here began permitting travel to China, more than half a million people have made the trip.
A bus pass is available for about $200 and permits unlimited travel for a week.