Astrophysicist Ron Mallett believes he's figured out how to build a time machine that would allow someone to travel to the past.

As the narrator says, the laws of physics don’t explicitly forbid time travel, but that doesn’t mean we’ll be building a working time machine anytime soon that can let us whip back and forth ...

The macOS Server app can back up all the Macs in your home, small office, or your enterprise environment.

However, he said he would need "galactic amounts of energy" and didn't know how big this "time machine" would have to be to make it work.

Time Machine and iCloud are two built-in backup systems that are easy to set up and use. For a Time Machine backup, Apple recommends having an external drive with twice the capacity of your Mac.