How to make a time machine

Travelling in time might sound like a flight of fancy, but some physicists think it might really be possible. BBC Horizon looked at some of the most promising ideas for turning this staple of science fiction into reality.

The Short Answer: Although humans can‘t hop into a time machine and go back in time, we do know that clocks on airplanes and satellites travel at a different speed than those on Earth. However, when we think of the phrase “time travel,” we are usually thinking of traveling faster than 1 second per second.

To adapt the wormhole for time travel, one of its mouths could be towed to a neutron star and placed close to its surface. The gravity of the star would slow time near that wormhole mouth, so that a time difference between the ends of the wormhole would gradually accumulate.

Time machines

It is generally understood that traveling forward or back in time would require a device — a time machine — to take you there. Time machine research often involves bending space-time so far that time lines turn back on themselves to form a loop, technically known as a “closed time-like curve.”

When Time Machine is turned on, it automatically backs up your Mac and performs hourly, daily, and weekly backups of your files. When you use Time Machine, Time Machine also saves a local snapshot you can use to recover previous versions of files, even if your backup disk is not attached.