I think the word "theoretically" is necessary here.
Line 1:
Line 1:
−
A time machine is a device which allows its user to travel through time, either to the past or the future. In general, such a device is believed to be against the laws of physics, though a one-way trip to the future could be organised in a number of ways that do not violate these laws. If real time machines exist they would involve tampering with [[black hole]]s billions of miles out in space, and would be massively expensive and impractical.
+
A '''time machine''' is a device which allows its user to travel through time, either to the past or the future. In general, such a device is believed to be against the laws of physics, though a one-way trip to the future could theoretically be organized in a number of ways that do not violate these laws. If real time machines exist they would involve tampering with [[black hole]]s billions of miles out in space, and would be massively expensive and impractical.
−
Time machines have played an important role in science fiction, ever since H.G. Well's famous book of the same name over a hundred years ago.
+
Time machines have played an important role in science fiction, ever since H.G. Wells's famous book of the same name over a hundred years ago.