Vincent Vega
- 42
- 0
Is there anything in the observable universe that weighs more? 1 teaspoon = billion tons
Neutron star: heaviest teaspoon of matter
- Level: Undergrad
- Thread starter Vincent Vega
- Start date
-
- Tags
- Matter Neutron Neutron star Star
Join the discussion
Registration is free. Start your own thread to ask a follow-up.
5 replies · 29K views
Discussion
Allday
- 164
- 1
hey Vega,
the matter in a neutron star is very (very very very) dense as you've grasped. Current theory explains neutron stars something like a giant nucleus, one that has a radius of about 10 km. (Actually the density of a neutron star is roughly 6.65 * 10^14 g/cm^3 while that in a typical nuclues is 'only' 2.3 * 10^14 g/cm^3). The star is being supported against gravitational collapse not by internal fusion like normal stars but by neutron degeneracy pressure. In plain english neutrons are a type of particle called fermions which don't like to be in the same place as other fermions so they exert a pressure if you bring them close together.
I don't think there are many things that could be denser because the nuetrons in the star are in the most closely packed configuration they can be in. I believe there are some speculative theories of quark stars where the individual neutrons dissolve into a sea of quarks, but there is no observational evidence that I am aware of. Also you have black holes which theoretically have infinite densities, but there is no theory that works well when trying to describe the singularity of a black hole.
Here are some other extreme facts about neutron stars
an object dropped from a height of 1m above the surface of a typical neutron star would impact the surface traveling at 4.3 million mph. that's one hell of a ride.
im kind of rambling here because its late, but another interesting thing is that the gravitational potential energy liberated when an object falls onto a neutron star is greater than the amount of energy one would liberate through the fusion of hydrogen atoms. ie throwing a chunk of hydrogen onto a nuetron star and collecting the energy that is radiated on the way down is a more efficient way to get energy than nuclear fusion!
hope your mind is warped
gabe
the matter in a neutron star is very (very very very) dense as you've grasped. Current theory explains neutron stars something like a giant nucleus, one that has a radius of about 10 km. (Actually the density of a neutron star is roughly 6.65 * 10^14 g/cm^3 while that in a typical nuclues is 'only' 2.3 * 10^14 g/cm^3). The star is being supported against gravitational collapse not by internal fusion like normal stars but by neutron degeneracy pressure. In plain english neutrons are a type of particle called fermions which don't like to be in the same place as other fermions so they exert a pressure if you bring them close together.
I don't think there are many things that could be denser because the nuetrons in the star are in the most closely packed configuration they can be in. I believe there are some speculative theories of quark stars where the individual neutrons dissolve into a sea of quarks, but there is no observational evidence that I am aware of. Also you have black holes which theoretically have infinite densities, but there is no theory that works well when trying to describe the singularity of a black hole.
Here are some other extreme facts about neutron stars
an object dropped from a height of 1m above the surface of a typical neutron star would impact the surface traveling at 4.3 million mph. that's one hell of a ride.
im kind of rambling here because its late, but another interesting thing is that the gravitational potential energy liberated when an object falls onto a neutron star is greater than the amount of energy one would liberate through the fusion of hydrogen atoms. ie throwing a chunk of hydrogen onto a nuetron star and collecting the energy that is radiated on the way down is a more efficient way to get energy than nuclear fusion!
hope your mind is warped
gabe
Last edited:
Vincent Vega
- 42
- 0
It is... my mind that is. That's pretty narly info!
Last edited:
whiteholes
- 27
- 0
What has density than a neutron star? Hmmm, that would be a super massive black hole in a very large galaxy. It should be sucking in millions of stars per second!
Allday
- 164
- 1
white holes said:
yeah i would agree you could say the density is higher (infinite), but you overestimated the accretion rate a little there white hole. Say we had a galaxy with 10 trillion stars in it (a large over estimate) then if they were disappearing at the rate of a million per second the whole galaxy would be swallowed in ten million seconds or about 116 days. galaxies last a little longer than that.
tribdog
- 779
- 17
and black holes don't really suck things in like that. If our sun suddenly turned into a black hole we wouldn't even notice it, other than it would stay nighttime and get really cold. Our orbit would be the exact same.