How big can a planet get before it forms a black hole or collapses into a singularity

[BoJangles]

<p style="margin-top:0cm;margin-left:0cm;margin-right:0cm" class="MsoNormal"><font face="Calibri" size="3">How big can a planet get before it forms a black hole or collapses into a singularity, what force is it that it has to over come, the strong force or something?</font></p><p style="margin-top:0cm;margin-left:0cm;margin-right:0cm" class="MsoNormal"><font face="Calibri" size="3">Additionally how big would the event horizon be on such a small black hole, it would have to be tiny?</font></p> <div class="Discussion_UserSignature"> <p align="center"><font color="#808080">-------------- </font></p><p align="center"><font size="1" color="#808080"><em>Let me start out with the standard disclaimer ... I am an idiot, I know almost nothing, I haven’t taken calculus, I don’t work for NASA, and I am one-quarter Bulgarian sheep dog.  With that out of the way, I have several stupid questions... </em></font></p><p align="center"><font size="1" color="#808080"><em>*** A few months blogging can save a few hours in research ***</em></font></p> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>How big can a planet get before it forms a black hole or collapses into a singularity, what force is it that it has to over come, the strong force or something?Additionally how big would the event horizon be on such a small black hole, it would have to be tiny? <br /> Posted by Manwh0re</DIV></p><p>It's not the size that matters.&nbsp; It's the density.&nbsp; How much mass you squeeze into a volume.&nbsp; This is referred to as the Schwarzschild radius.&nbsp; The Schwarzschild radius (aka event horizon) for the earth would be 9mm.&nbsp; If you squeeze the mass of the earth into a spherical volume with a radius of 9mm it will fom a black hole.&nbsp; The event horizon would be 18mm in diamter.</p><p>The force it has to overcome is the neuton degeneracy pressure.&nbsp; Once you are passed that (ignoring hypothetical quark degeneracy), you have overcome and violated the Pauli Exclusion Principle.&nbsp; There's no known forces to stop a complete collapse. </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[BoJangles]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>It's not the size that matters.&nbsp; It's the density.&nbsp; How much mass you squeeze into a volume.&nbsp; This is referred to as the Schwarzschild radius.&nbsp; The Schwarzschild radius (aka event horizon) for the earth would be 9mm.&nbsp; If you squeeze the mass of the earth into a spherical volume with a radius of 9mm it will fom a black hole.&nbsp; The event horizon would be 18mm in diamter.The force it has to overcome is the neuton degeneracy pressure.&nbsp; Once you are passed that (ignoring hypothetical quark degeneracy), you have overcome and violated the Pauli Exclusion Principle.&nbsp; There's no known forces to stop a complete collapse. <br />Posted by derekmcd</DIV><br /><br />hrm interesting. i find it hard to believe that small black holes exist at all. but hey im just learning <div class="Discussion_UserSignature"> <p align="center"><font color="#808080">-------------- </font></p><p align="center"><font size="1" color="#808080"><em>Let me start out with the standard disclaimer ... I am an idiot, I know almost nothing, I haven’t taken calculus, I don’t work for NASA, and I am one-quarter Bulgarian sheep dog.  With that out of the way, I have several stupid questions... </em></font></p><p align="center"><font size="1" color="#808080"><em>*** A few months blogging can save a few hours in research ***</em></font></p> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>hrm interesting. i find it hard to believe that small black holes exist at all. but hey im just learning <br /> Posted by Manwh0re</DIV></p><p>Depends on your definition of small.&nbsp; Mathematically, the Schwarzschild radius can be any size.&nbsp; In reality, though, the only black holes indirectly observed have been either stellar sized or supermassive.&nbsp; Nothing in between.&nbsp; There was an article recently concerning intermediate sized black holes in the center of globular clusters (maybe what triggered your last couple questions?), but none were detected.&nbsp; Primordial black holes are thought to have exsted, but would not be around today to be detected as they, theoretically, would have evaporated due to Hawking radiation.&nbsp; There's also the prospect of creating micro-black holes in the LHC. </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[BoJangles]

<p style="margin-top:0cm;margin-left:0cm;margin-right:0cm" class="MsoNormal"><font face="Calibri" size="3">Thanks for your input&hellip;</font></p><p style="margin-top:0cm;margin-left:0cm;margin-right:0cm" class="MsoNormal"><font face="Calibri" size="3">Actually I was reading that same article somewhere, maybe even space.com, but more to my point, I was wondering why that small masses even form black holes. </font></p><p style="margin-top:0cm;margin-left:0cm;margin-right:0cm" class="MsoNormal"><font face="Calibri" size="3">They seem such dramatic ends to matter they ort to just exist in the largest of examples. Imagine the energies of even 2 small singularities combining; I suppose that is what they are studying in gamma ray bursts. It&rsquo;s easy to see the maths would go berserk even if 2 small black holes combined</font></p><p style="margin-top:0cm;margin-left:0cm;margin-right:0cm" class="MsoNormal"><font face="Calibri" size="3">What is the closest Stella black holes observed to earth? I&rsquo;d like to see this empirical evidence for Stella black holes. How are they deriving them? What evidence is there for them? </font></p><p style="margin-top:0cm;margin-left:0cm;margin-right:0cm" class="MsoNormal"><font face="Calibri" size="3">Evidence for a Stella black hole (that I can think of) would be a very small orbit of a large star in a binary setup with the said BH? Or is there other evidence? I'm assuming the radius of an actual black hole is a point.</font></p><p style="margin-top:0cm;margin-left:0cm;margin-right:0cm" class="MsoNormal"><font face="Calibri" size="3">Could there be a mistake with stellar black holes. is it just a maths prediction or are they actually seeing proper motion of stars around very small objects (unusually small).</font></p> <div class="Discussion_UserSignature"> <p align="center"><font color="#808080">-------------- </font></p><p align="center"><font size="1" color="#808080"><em>Let me start out with the standard disclaimer ... I am an idiot, I know almost nothing, I haven’t taken calculus, I don’t work for NASA, and I am one-quarter Bulgarian sheep dog.  With that out of the way, I have several stupid questions... </em></font></p><p align="center"><font size="1" color="#808080"><em>*** A few months blogging can save a few hours in research ***</em></font></p> </div>

 

[UFmbutler]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Thanks for your input&hellip;Actually I was reading that same article somewhere, maybe even space.com, but more to my point, I was wondering why that small masses even form black holes. They seem such dramatic ends to matter they ort to just exist in the largest of examples. Imagine the energies of even 2 small singularities combining; I suppose that is what they are studying in gamma ray bursts. It&rsquo;s easy to see the maths would go berserk even if 2 small black holes combinedWhat is the closest Stella black holes observed to earth? I&rsquo;d like to see this empirical evidence for Stella black holes. How are they deriving them? What evidence is there for them? Evidence for a Stella black hole (that I can think of) would be a very small orbit of a large star in a binary setup with the said BH? Or is there other evidence? I'm assuming the radius of an actual black hole is a point.Could there be a mistake with stellar black holes. is it just a maths prediction or are they actually seeing proper motion of stars around very small objects (unusually small). <br /> Posted by Manwh0re</DIV></p><p>There are observed binary systems with at least one of the objects being a stellar mass black hole.&nbsp; Also, stellar mass black hole existence can be inferred by gravitational microlensing events(see http://www.space.com/scienceastronomy/astronomy/maverick_black_hole_000113.html ). &nbsp;&nbsp;</p> <div class="Discussion_UserSignature"> </div>