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Black holes form natural time machines that allow travel to both the past and the future. But don’t expect to be heading back to visit the dinosaurs any time soon.
At present, we don’t have spacecraft that could get us anywhere near a black hole. But, even leaving that small detail aside, attempting to travel into the past using a black hole might be the last thing you ever do.
A black hole is an extremely massive object that is typically formed when a dying star collapses in on itself.Like planets and stars, black holes have gravitational fields around them. A gravitational field is what keeps us stuck to Earth, and what keeps Earth revolving around the Sun.
As a rule of thumb, the more massive an object is, the stronger its gravitational field.
Earth’s gravitational field makes it extremely difficult to get to space. That’s why we build rockets: we have to travel very fast to break out of Earth’s gravity.
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An artist’s illustration of a black hole. (Image credit: solars even via Getty Images)
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