# The trouble with a singularity [duplicate]

As an engineer, we are taught that the root cause of any problem can be solved if we ask why 5 times. Sometimes you can figure it out at 4 and sometimes at 6, but it always averages to 5 times. - You can occasionally add a "how" into that root cause analysis, but generally, it is "why".

So I was reading an article on the internet about how black holes form and I started asking why.

Unfortunately, my analysis broke down on the first why.

1. So why a singularity? - If the sum of a massive star's core is crushed to become a black hole, why and how does it become a singularity? How do you crush point-like particles (quarks, electrons, etc) beyond their current size? Logic dictates that there has to be a size where you cannot make an object anymore dense.

How do you get around Heisenberg's uncertainty principle? We now know the exact location for all of the matter in the black hole. We also should know the state of all of the matter in the black hole.

How do you get around Pauli's Exclusion Principle? - Do electrons cease being electrons when you squeeze them hard enough? If so, at what point is it no longer an electron?

If a BH is a point-like object smaller than an electron, how does matter falling onto it smear over the surface?

Can an object be Planck size and still be a singularity? If so this would solve some of these questions....

Does matter falling onto the surface of a BH cause it to shrink further or does it grow with all of the matter smearing onto it? If it grows in size, does this mean its gravity gets weaker? After all, its gravity is inversely proportional to its size isn't it?

## marked as duplicate by Ben Crowell, stafusa, John Rennie black-holes StackExchange.ready(function() { if (StackExchange.options.isMobile) return; $('.dupe-hammer-message-hover:not(.hover-bound)').each(function() { var$hover = $(this).addClass('hover-bound'),$msg = $hover.siblings('.dupe-hammer-message');$hover.hover( function() { $hover.showInfoMessage('', { messageElement:$msg.clone().show(), transient: false, position: { my: 'bottom left', at: 'top center', offsetTop: -7 }, dismissable: false, relativeToBody: true }); }, function() { StackExchange.helpers.removeMessages(); } ); }); }); Mar 24 at 9:37

• – Ben Crowell Mar 23 at 14:17
• If a BH is a point-like object smaller than an electron, how does matter falling onto it smear over the surface? It's not really true that a black hole singularity is pointlike. physics.stackexchange.com/questions/144447/… – Ben Crowell Mar 23 at 14:17
• "After all, its gravity is inversely proportional to its size isn't it?" . it is mass for the gravitational formula, not size. There is no definitive quantization of gravity, so one cannot mix up classical with quantum except as effective theories. In general quantum mechanics makes classical singularities fuzzy, See the fuzziness in the current Big Bang model, where effective quantization of gravity is used en.wikipedia.org/wiki/Big_bang – anna v Mar 23 at 17:53
• please note that in classical physics there are singularities all over (Coulomb potential for example) that the quantum mechanical formulation eliminates – anna v Mar 23 at 18:03
• I recommend you read Kip Thorne's book "Black Holes And Time Warps", it will answer most if not all of your questions. – niels nielsen Mar 23 at 19:02