Nov 28, 2024 07:47 AM
(This post was last modified: Nov 28, 2024 07:50 AM by C C.)
Naked singularities: how quantum black holes explain why we don’t see the end of space and time
https://theconversation.com/naked-singul...ime-244563
INTRO: Albert Einstein’s theory of gravity, general relativity, is famously incomplete. As proven by physics Nobel laureate Roger Penrose, when matter collapses under its own gravitational pull, the result is a “singularity” – a point of infinite density or curvature.
At a singularity, space, time and matter are crushed and stretched into nonexistence. The laws of physics as we know them suffer a complete breakdown. If we could observe singularities, our physical theories couldn’t be used to predict the future from the past. In other words, science would become an impossibility.
Penrose also realised nature may hold a remedy for this fate – black holes. A defining feature of a black hole is its event horizon, a one-way membrane in space-time. Objects – including light – that cross the event horizon can never leave due to the black hole’s incredibly strong gravitational pull.
In all the known mathematical descriptions of black holes, singularities are present in their core. Penrose postulated that all the singularities of gravitational collapse are “clothed” by the event horizons of black holes – meaning we could never observe one. With the singularity inside the event horizon, physics in the rest of the universe is business as usual.
This conjecture of Penrose, that there are no “naked” singularities, is called cosmic censorship. After half a century, it remains unproven and one of the most important open problems in mathematical physics. At the same time, finding examples of instances where the conjecture doesn’t hold up has proven equally difficult.
In recent work, published in Physical Review Letters, we showed that quantum mechanics, which rules the microcosmos of particles and atoms, supports cosmic censorship... (MORE - details)
https://theconversation.com/naked-singul...ime-244563
INTRO: Albert Einstein’s theory of gravity, general relativity, is famously incomplete. As proven by physics Nobel laureate Roger Penrose, when matter collapses under its own gravitational pull, the result is a “singularity” – a point of infinite density or curvature.
At a singularity, space, time and matter are crushed and stretched into nonexistence. The laws of physics as we know them suffer a complete breakdown. If we could observe singularities, our physical theories couldn’t be used to predict the future from the past. In other words, science would become an impossibility.
Penrose also realised nature may hold a remedy for this fate – black holes. A defining feature of a black hole is its event horizon, a one-way membrane in space-time. Objects – including light – that cross the event horizon can never leave due to the black hole’s incredibly strong gravitational pull.
In all the known mathematical descriptions of black holes, singularities are present in their core. Penrose postulated that all the singularities of gravitational collapse are “clothed” by the event horizons of black holes – meaning we could never observe one. With the singularity inside the event horizon, physics in the rest of the universe is business as usual.
This conjecture of Penrose, that there are no “naked” singularities, is called cosmic censorship. After half a century, it remains unproven and one of the most important open problems in mathematical physics. At the same time, finding examples of instances where the conjecture doesn’t hold up has proven equally difficult.
In recent work, published in Physical Review Letters, we showed that quantum mechanics, which rules the microcosmos of particles and atoms, supports cosmic censorship... (MORE - details)