Scientists Discover Black Holes That Erase Your Past

Wednesday, 21 February 2018 - 9:09AM
Space
Weird Science
Astrophysics
Wednesday, 21 February 2018 - 9:09AM
Scientists Discover Black Holes That Erase Your Past
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Image credit: composite created from images on Pixabay
In season five of the modern Doctor Who, The Doctor comes across a crack in space and time that absorbs people, objects – even entire planets.

Not only does this crack erase everything it swallows, but a human who is absorbed by the crack is also entirely removed from history. It's as if they had never been born, and they themselves are trapped forever in a void where the rules of cause and effect are distorted.

This phenomenon may actually occur in the center of some black holes, albeit in their fashion. People who enter smooth, rotating black holes (known as Kerr-Newman-de Sitter black hole) wouldn't be erased from history outside the hole, but their own past would be obliterated. The laws of cause and effect would no longer apply to them, and they'd end up eternally trapped in a "wibbly-wobbly, timey-wimey" void where actions don't necessarily lead to the reactions of the "real" world.

According to UC Berkeley postdoctoral fellow Peter Hintz, the mathematics within Kerr-Newman-de Sitter black holes cause a breakdown of the rules outlined in Einstein's theory of relativity. Because of the constantly-expanding universe – and the fact that this expansion is accelerating – spacetime naturally warps and stretches. This is particularly true in black holes, where gravity's pull is so strong that time creeps to a standstill. These powerful forces push and pull at each other, potentially creating a place within the center of certain black holes where the past, present, and future all play out in strange ways.

 

At the center of such a black hole, a person would experience infinite futures, all occurring more or less simultaneously. It's a difficult concept for us measly four-dimensional beings to wrap our heads around, but the nearest visualization for this kind of space is Murph's bedroom within a five-dimensional tesseract in Interstellar, where different points in time pile up on each other. In reality, being inside a black hole probably doesn't look anything like this, but the only other way to describe it would be the coolest acid trip in the universe.

Scientists have long theorized that this kind of space exists inside some black holes with an electrical charge, but it's been considered a moot discussion: charged black holes can't exist very long, as they attract oppositely charged matter to fill them up. Hintz' big contribution was finding equations that show even some uncharged black holes could work the same way, distorting spacetime until it makes utterly no sense.

Such a trip into the realm beyond cause and effect would be difficult to achieve. Travelers would need to navigate past the Cauchy horizon, where the rules of our universe break down. This could theoretically be possible in black holes that are both large and dense enough, but nobody will ever be able to confirm this – the journey inside is a one-way trip.

While we're not going to learn the secrets of the space within black holes any time soon, it is interesting to speculate what it might be like to be trapped in a realm where time stops behaving the way it should.

It turns out that even the rules of the universe we think are solid can give way under the right circumstances.

Science
Black Holes
Space
Weird Science
Astrophysics
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