Neutron Star Density

[Grooveriding]

Yup. Also the philosopher in me feels our entire society would need a huge shift in priorities as well as the human race needing further social evolution for any sort of real space exploration to be achievable and more widely seen as a valuable goal.

 

[Mark R]

And when that teaspoon full of neutron star material has finished falling the 1 yard to the surface, it will impact with the energy of about 10 million megatons.

You may want to retire to a safe distance before tipping the spoon.

 

[moonbogg]

There are about 5 grams of water in a teaspoon and a neutron star is ~100 quadrillions times as dense as water, on average, according to Wikipedia.

I'm cheating, this site calculates the force of impact of 5,000,000,000,000,000 grams dropped one meter on Earth as 490000000000000000N of force, which calculates to 49,966,094,436,000 metric tons of force.

Does that sound right? Nature is pretty amazing.

I'm pretty sure that if you dropped any amount of that stuff here on earth, that it would just sink right to the center of the earth and stay there, that is if you only take the mass of the stuff into consideration.
I'm pretty sure that if you removed a small piece of the star that it would fly apart and explode at some distance away. I think it needs the gravity of the whole star to keep it as dense as it is, otherwise it would spring out and blow the hell up. That's my guess anyway.

Regarding the TV shows, I love them. I'm glad we have smart people who are able to tell the story like they do. I'm confident we will one day be able to go anywhere and do almost anything. It just makes sense to me. It seems that's just how it will be.

 

[MrPickins]

black holes are infinitely denser than neutron stars

Fixed that for you.

 

[bobeedee]

So, a Priest, a Rabbi, and a Neutron Star walk into a bar....

 

[disappoint]

So...a priest, rabbi and a bar crash into a neutron star.

 

[Ruptga]

I've read that they're called Neutron Stars because they're so dense that atoms collapse under their own weight, making the entire thing one mass of wiggly subatomic particles that together behave like a single neutron. That might be an out of date explanation, but they do definitely ride the line between white dwarfs and black holes; a little less mass and you have a white dwarf, a little more mass and you end up with a black hole. Also physics breaks down a little bit in their cores, where the density is actually greater than that of a normal atomic nucleus.

 

[KillerBee]

I think the "Highly Technical" forum sprang a leak

 

[Printer Bandit]

So does this prove that God exists?

 

[Gibsons]

Here's something sort of crazy - a red giant with a neutron star core (maybe). Basically a red giant merges or collides with a neutron star. The red giant has enough energy to stay inflated, at least for a while.
http://www.scientificamerican.com/article/bizarre-star-could-host-a-neutron-star-in-its-core/

 

[Jeff7]

https://www.youtube.com/watch?v=TbdH28prqac

Thor's hammer.

:hmm:
The inside of a star doesn't seem like a good place to create a sophisticated piece of technology.

But maybe our manufacturing capabilities just haven't gotten that far yet.

 

[SlowSpyder]

I'm pretty sure that if you dropped any amount of that stuff here on earth, that it would just sink right to the center of the earth and stay there, that is if you only take the mass of the stuff into consideration.
I'm pretty sure that if you removed a small piece of the star that it would fly apart and explode at some distance away. I think it needs the gravity of the whole star to keep it as dense as it is, otherwise it would spring out and blow the hell up. That's my guess anyway.

Regarding the TV shows, I love them. I'm glad we have smart people who are able to tell the story like they do. I'm confident we will one day be able to go anywhere and do almost anything. It just makes sense to me. It seems that's just how it will be.

Yea, without the intense gravity of the star itself to hold it together, I can't see how it would on earth. But, the numbers are there to illustrate just how dense it is and the amounts of energy involved.


So why does a neutron star become a neutron star? Is it not quite massive enough to become a black hole?

 

[NikolaeVarius]

Yea, without the intense gravity of the star itself to hold it together, I can't see how it would on earth. But, the numbers are there to illustrate just how dense it is and the amounts of energy involved.


So why does a neutron star become a neutron star? Is it not quite massive enough to become a black hole?

Yes. All particles have a tendency to stay away from each other because of their charges and also the pauli exclusion principal. The mass of the star, if above the Chandreskar Limit(Or however its actually spelled) which governs the maximum size of a star before it can't become a standard white dwarf, causes the gravitational force to overcome the tendency for electrons to stay away from each other, called the electron degeneracy pressure. The electrons then combine with the protons in the star to become neutrons, a.k.a why its called a neutron star.

After that, there is neutron degeneracy pressure, which governs a neutrons ability to stay away from each other. It's theorized at the middle of neutron stars, there is exotic matter in the form of a quark-gluon plasma where neutron degeneracy is overcome. Past that, there is quark degeneracy, and if the star is simply that massive and the gravitational force overcomes the quark degeneracy, then you finally get a black hole.

 

[Gibsons]

So why does a neutron star become a neutron star? Is it not quite massive enough to become a black hole?

Right. Enough gravity to squish all the atoms, but not enough so that light can't escape.

 

[Legios]

1 Yard is not 1 meter, that sort of conversion would break my head.

 

[Jaepheth]

Degenerates

 

[dave_the_nerd]

1 Yard is not 1 meter, that sort of conversion would break my head.

Add 10%.

Same as with pounds->kilos. (Multiply by two, add 10%.)

Probably not accurate enough for "SCIENCE!!!" but it's close enough for terrestrial work.

 

[Legios]

Add 10%.

Same as with pounds->kilos. (Multiply by two, add 10%.)

Probably not accurate enough for "SCIENCE!!!" but it's close enough for terrestrial work.

10% at these tolerances is a lot.

 

[BurnItDwn]

Do not eat the neutron star at the buffet, you will feel very heavy!

 

[moonbogg]

Yea, without the intense gravity of the star itself to hold it together, I can't see how it would on earth. But, the numbers are there to illustrate just how dense it is and the amounts of energy involved.


So why does a neutron star become a neutron star? Is it not quite massive enough to become a black hole?

Yeah, its between a white dwarf and a black hole as far as density goes from what I've gathered. Also, as the star collapses into its neutron star form, an extreme spin can be generated. A neutron star can rotate as fast as 43,000 RPM.
That's a solid sphere 7.5 miles in diameter, that weights as much as two of our suns, and its rotating in space as fast as forty three thousands revolutions per minute...and it doesn't fly apart. That surface speed is....insane, and it holds together.

I did the math. The surface speed of the star would be 60.7 million miles per hour.

7.5 miles x 3.14 = 23.55 mile circumference
23.55 miles x 43,000 rpm = 1.02 million miles per minute
x 60 in an hour = 60.7 million miles per hour

(numbers were rounded)

 

[Ruptga]

I don't know why you guys insist on converting to miles and pounds. Science is done in kilometers and kg, and if you think that's silly just ask the Mars Climate Orbiter why.

Oh and if you're having a hard time grasping a mass number, look at it in tons. Metric tons and imperial tons are almost identical, and either is a lot more useful for getting a feel for really large numbers.

 

[Atomic Playboy]

I don't know why you guys insist on converting to miles and pounds. Science is done in kilometers and kg, and if you think that's silly just ask the Mars Climate Orbiter why.

Because we're talking about hypothetical scenarios, and people in America have a much easier time envisioning those scenarios when they're presented in common units. It's not like if we make a rounding error in our completely theoretical layman discussion of neutron stars we're going to smash a $300 million piece of equipment to pieces.

 

[moonbogg]

I don't know why you guys insist on converting to miles and pounds. Science is done in kilometers and kg, and if you think that's silly just ask the Mars Climate Orbiter why.

Oh and if you're having a hard time grasping a mass number, look at it in tons. Metric tons and imperial tons are almost identical, and either is a lot more useful for getting a feel for really large numbers.

Jesus Christ man.

97 million Km/h. Happy?

 

[Mark R]

I don't know why you guys insist on converting to miles and pounds. Science is done in kilometers and kg, and if you think that's silly just ask the Mars Climate Orbiter why.

The thing I always liked about astrophysics is that the error bars are so wide, that you can use whatever units you like, and it would still be within the error bars.

 

[Ruptga]

Because we're talking about hypothetical scenarios, and people in America have a much easier time envisioning those scenarios when they're presented in common units. It's not like if we make a rounding error in our completely theoretical layman discussion of neutron stars we're going to smash a $300 million piece of equipment to pieces.

Of course, but does saying "5.918×10^30 to 9.206×10^30 lbs" really help envision what we're talking about? The differences between 10^10 and 10^30 or a billion billion and a billion billion billion is completely lost on most people. If we're going to convert to something a layman can understand, we could at least try "500,000 to 700,000 times the mass of the Earth" before trying to shoehorn familiar units into completely unintelligible numbers.

Jesus Christ man.

97 million Km/h. Happy?

"27,000 km/s" I am now Even "16,700 miles per second" would be easier to grasp, I think. Even better would be saying "something moving that fast around Earth would go around it four times in under a second."