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View Full Version : If you compressed the Earth to the size of a beach ball



dnj123
2018-Nov-17, 01:56 PM
Assume it's not enough to form a black hole. What would that look like and what state of matter would the Earth be in? Would it be a neutron star?

Hornblower
2018-Nov-17, 02:05 PM
That would be vastly more dense than a neutron star. The density of a neutron star corresponds to a diameter of a few hundred feet for Earth's mass.

There is no known force which can compress an isolated Earth-mass body to such conditions, but in a thought exercise anything goes.

dnj123
2018-Nov-17, 04:33 PM
Thanks. From the other thread I'm starting to get it.

DaveC426913
2018-Nov-17, 06:50 PM
This chart shows the radius of a neutron star as it corresponds to Solar masses.

The implication of the chart is that a naturally-occuring neutron star cannot form that is less than about .3 Sols.

However, if were to extrapolate it downward, it would be about 450 metres in radius. (I simply Googled for that)

A BH, on the other hand, would be about 1cm in radius.

23747

Delvo
2018-Nov-23, 01:39 PM
So what class of object is between neutron stars and a black holes?

grant hutchison
2018-Nov-23, 01:51 PM
So what class of object is between neutron stars and a black holes?Maybe nothing - once neutron degeneracy pressure is overwhelmed, there may be no force that can oppose the collapse to a black hole. Or perhaps a quark star, but we don't know much about quark degeneracy pressure.

Grant Hutchison

Cougar
2018-Nov-23, 08:49 PM
So what class of object is between neutron stars and a black holes?


Maybe nothing....

I believe that's correct. I think Chandrasekhar (https://www.britannica.com/biography/Subrahmanyan-Chandrasekhar) calculated (on his sea voyage to England in 1930) that there is no stable state between a neutron star and black hole.

grant hutchison
2018-Nov-23, 09:27 PM
I believe that's correct. I think Chandrasekhar (https://www.britannica.com/biography/Subrahmanyan-Chandrasekhar) calculated (on his sea voyage to England in 1930) that there is no stable state between a neutron star and black hole.Chandrasekhar didn't know about quarks, though.

Grant Hutchison