<story><title>Physicists identify the engine powering black hole energy beams</title><url>https://www.quantamagazine.org/physicists-identify-the-engine-powering-black-hole-energy-beams-20210520/</url></story><parent_chain><item><author>infogulch</author><text>Agree! This is my favorite crazy pet theory: spacetime is simulated on a flat 3d substrate with constant compute and memory per volume, which runs at a fixed rate in time (c) [1], and to account for a high density of mass requiring more compute the simulation is slowed down proportionally. Then, black holes are just the extreme end of this slowing down of the simulation.&lt;p&gt;[1]: You always move at a constant speed: the speed of light. But that speed can be broken down into two component directions which you can trade off: time and space. You typically move near the speed of light in the &lt;i&gt;time&lt;/i&gt; direction, meaning your speed through the space direction is comparatively low.</text></item><item><author>eloff</author><text>Simulation theory speculation:&lt;p&gt;If the universe is a simulation, when there gets too much matter in an area to simulate all the interactions, a black hole is the way programmers fixed that - it gets turned into a singularity and isn&amp;#x27;t simulated anymore except as one point source of gravity (or in a more complex way if black holes preserve entropy - jury is still out on that one.)&lt;p&gt;Silly and untestable, but fun to think about, like the rest of simulation theory. It would be required to do something like that if you&amp;#x27;re running a simulation with finite resources. You couldn&amp;#x27;t just keep piling matter into a finite area without bound, eventually you&amp;#x27;d overwhelm what you can compute. Same reason one might want a hard speed limit like the speed of light.&lt;p&gt;Interestingly this is a not a discrete function, time slows near large masses, which would allow the computer to keep up as matter in an area increased, much as you&amp;#x27;d expect in a simulation.</text></item></parent_chain><comment><author>taneq</author><text>It&amp;#x27;s because the stronger the forces and the higher the velocity in a cell of the simulation, the more iterations the numerical integrator needs to perform to maintain acceptable accuracy. It&amp;#x27;s obvious, really. ;)&lt;p&gt;Also the universe isn&amp;#x27;t actually expanding and the red shift we see in distant stars is just a numerical error due to the enormous number of steps between here and there. :)</text></comment>
<story><title>Physicists identify the engine powering black hole energy beams</title><url>https://www.quantamagazine.org/physicists-identify-the-engine-powering-black-hole-energy-beams-20210520/</url></story><parent_chain><item><author>infogulch</author><text>Agree! This is my favorite crazy pet theory: spacetime is simulated on a flat 3d substrate with constant compute and memory per volume, which runs at a fixed rate in time (c) [1], and to account for a high density of mass requiring more compute the simulation is slowed down proportionally. Then, black holes are just the extreme end of this slowing down of the simulation.&lt;p&gt;[1]: You always move at a constant speed: the speed of light. But that speed can be broken down into two component directions which you can trade off: time and space. You typically move near the speed of light in the &lt;i&gt;time&lt;/i&gt; direction, meaning your speed through the space direction is comparatively low.</text></item><item><author>eloff</author><text>Simulation theory speculation:&lt;p&gt;If the universe is a simulation, when there gets too much matter in an area to simulate all the interactions, a black hole is the way programmers fixed that - it gets turned into a singularity and isn&amp;#x27;t simulated anymore except as one point source of gravity (or in a more complex way if black holes preserve entropy - jury is still out on that one.)&lt;p&gt;Silly and untestable, but fun to think about, like the rest of simulation theory. It would be required to do something like that if you&amp;#x27;re running a simulation with finite resources. You couldn&amp;#x27;t just keep piling matter into a finite area without bound, eventually you&amp;#x27;d overwhelm what you can compute. Same reason one might want a hard speed limit like the speed of light.&lt;p&gt;Interestingly this is a not a discrete function, time slows near large masses, which would allow the computer to keep up as matter in an area increased, much as you&amp;#x27;d expect in a simulation.</text></item></parent_chain><comment><author>shaded-enmity</author><text>My crazy pet theory: computational bandwidth is constant for any spacetime coordinate. According to Bekenstein bound the lower the temperature of the system the cheaper it is to flip a bit of information. As time progresses the CMBR gets colder, so it&amp;#x27;s cheaper to flip a bit, but conversely, as time progresses our Hubble volume gets smaller, limiting our total available energy budget to perform a bit flip.</text></comment>