We look at mind-boggling neutron stars and Saturn in this film about the extremes of density. More symbols explained at www.sixtysymbol... With Meghan Gray
It's science buddy and we love it forever,unlike bitches and governments that get rid of entire library and toss in the recicliling. They disappeared w/ books in Stamford CT ,because there was a lot of future scientists over there but they were foreigners.
Just a little correction for 0:56~, she means 1000 kg/m^3. kg/m^2 would be a unit of pressure, rather than density. (1000 kg/m^2 = 9,800 N/m^2 = 9.8 kPa)
@Trouterr The explanation is that gravity sqashes the atoms so that orbiting electrons are forced into a nucleus, the opposite charges of protons and electrons cancel each other out, thus the name, a neutron star. We have an idea of that kind of matter, its called a degenerate matter and there are a few types of it. It's gravity that holds it together, and we have no idea if a neutron stars "undense", but if they did by some strange phenomenon, it would take tens of billions of years.
Nuetrons, when compressed can occupy the same space. There's a limit to the number that can occupy the same space dependent on the exclusion principle.
@blenderpanzi"Why does neutron stars have magnetic fields when they are made of nothing but neutrons (no electrical charge)?" because of a phenomenon relying on the Kelvin theorem, the magnetic field is conserved through states a system undergoes through. In summary, whatever the star's magnetic field was before the gravitational collapse, it has the same after it became a neutron star. And because the matter density is higher, so is the density of the magnetic field.
Directly. Considering their mutual gravitational attraction, dark and baryonic matter are found together. Observations of the "recent" collision of the two galaxies in the Bullet Cluster shows most of the matter to have condensed in the center because of loss of angular momentum. Weak gravitational lensing of the system shows most of the mass to be outside of the central region. From this, we can infer that the dark matter passed right through the collision and separated from the matter. (cont)
What sustains neutron stars? I thought that the strong force was extremely attractive between nucleons, but there must be some kind of "pressure" in between neutrons resisting the pull of gravity, like in the sun, the energy released by fusion keeps the sun stable.
Hey Meghan, Hi diego here. You make think about the neutron stars of being lot and lot of matter stuck together in a single place, and what I understood is that this atoms lose their charges and they became neutral. So if I got it right, this lumps of matter are actually atoms. are they? If they are atoms with no charge at all, they can be put in a periodic table in some way?
EDIT "Observations of the "recent" collision of the two galaxies in the Bullet Cluster " Should read: Observations of the "recent" collision of the two galaxy -clusters- in the Bullet Cluster
It's called Fermi's exclusion principle. Simply put, nucleons can pack together very closely but not merge ("occupy the same quantum state"). The neutron star, despite it's density, still cannot overcome the repulsion of neutrons when very, very close. In fact, some models predict that in the inner part of a NS the neutrons loose their identity and we get some superdense quark soup. A body dense enough to overcome Fermi's principle becomes a black hole.
About "empty" - long ago I attended a lecture by John Archibald Wheeler in which he described a subatomic particle (don't ask, I was a history major) as "a bubble in the vacuum." So it's emptiness within emptiness. About Saturn - surely its density is not uniform; is there not a point where Saturn's core becomes solid (like Earth's) from the pressure?
In a sense does this video support the philosophical idea of atomisation, based on that atoms are more or less hollow inside and therefore, what we see and paramountly what we touch is not real, it is only how we perceive it, which, I suppose is based fundamentally on what we're taught growing up, such as the feel of shapes and household objects as infants?
Old video I know, but a question: if neutron starts are made up of only neutrons, and free neutrons decay in about 14 min, are neutron stars evaporating at a decent pace?
What you're getting at is pretty interesting! Of course, they are known as neutron stars because they are just that, completely composed of NEUTRONS. Atoms consist of protons and electrons (and usually neutrons). Since there are just neutrons, and the only thing keeping them together is their acquired gravity and not the strong force like in atoms. Very cool idea tho!
@CandelaCenter I was woundering how much a cubic cenimeter of white dwarf matter weighs on a white dwarf. I could do the math but I'm lazy and your answer gives me a good enough idea. This isn't the right place but if your in the mood to answer I have another question. If you were to rearrange the earths interior so that the core was not in the center but touching the surface on one side, would the difference in gravity between that point and its antipode be noticeable?
A great deal denser. Per cubic mm, a neutron star would weigh roughly and upwards of 8.0*10^8 kg (800,000,000kg). The moon's mass is 7.34767309 × 10^22kg (73,476,730,900,000,000,000,000kg), which is very roughly the mass of a micro black hole 1mm big.
(cont) If dark matter interacted through electromagnetism as does baryonic matter, it would have lost much more angular momentum and condensed as well. This would cause weak gravitational lensing observations to show most of the mass in the center, which is does not. Yes, there is evidence that Dark Matter did play a crucial role in the formation and evolution of galaxies (not solar systems though), mainly through high end modeling.
@NekuraCa I think not, simply because the immense amount of gravity needed to keep that in place would be lost (the neutron star itself), and it would be probably uncompressed somehow. IMO XD
One thing I've always wondered about white dwarf and neutron stars. If we could get a teaspoon of the material away from the object, would it stay in it's compressed state?
@puncheex haha wow that's a crazy concept to grasp XD I mean, the density is always scaling up in a black hole... but how can it be infinite? It always has more mass, but its not infinite right? Do we say its infinite because of its singularity or because its impossible to measure it correctly due to its restless matter assimilation? Thx for the reply, you seem to know a lot about this subject (I'm just a noob on the other hand XD)
Nice, but Mr Picky is going to "weigh in" here...weight is measured in Newtons, MASS is measured in kilograms...and like I tell the kids at school, it's "square metres" not metres squared and "cubic metres" not meters cubed...one is a unit area or volume and the other is a mathematical abstraction.
Has this been shown to be true in experiment, directly or indirectly? I know some think dark matter is super symmetric particles, but I don't think they have ever been detected. Also has anyone been able to simulate say the formation of an accretion disk with a theorized kind of dark matter involved? It seems that dark matter must be necessary in the formation of galaxies as well as solar systems.
Of course force ≠ mass, mass is there as part of the definition of force with a specific acceleration (g) already factored in, thus cementing its referring to weight force. I realise it's not rigorous, but it is the most realisable use of kg/m^2 considering how much sense "mass per unit of area" makes. Would have stated with less absolute terms but I wanted to put it simply.
@CandelaCenter I think you mean geometry, "deals in exact shapes and areas, blah blah" and then only exact with polygons, with circles you have to use PI and because we are not god we do not know the full form or PI, which to me says its wrong, we can count the exact number or atoms on the head of a pin but we can't use math to come up with the exact surface area. I personally am a philosopher, the ideas are what is important to me being able to use them to do real work.
I can't imagine you'd be able to put them in a periodic table as it is composed using the properties of electrons. It would be pretty cool, though, to do imaginary chemistry with whole stars.
@CandelaCenter thank you. I find a lot of the books I read on physics when I was in middle school and high school to be terribly inaccurate. Even after that, it is hard to get good simple answer on nuclear synthesis and where the other 80 elements come from. side note I wounder how much that would weigh on a white dwarf?
Partial answer to my own question from Scientific American, May 2000, "Making Metallic Hydrogen", 84-90: "...Jupiter...is so massive that fluid hydrogen inside the gas giant is believed to be squeezed into metallic form." Saturn can't be that much lighter. Exo-geology revealed by exploring strata of old magazines!
@CandelaCenter That's why books written by non scientists aren't very good. Normal people hear one number and latch on, when in reality there is always a range whether due to actual conditions or inaccuracies of measure. I took White Dwarf=130000000 lbs divided by 100 to get per pound then took that times .45359237 to get what a kilogram weighs on a white dwarf time 1000 to get what a tonne would weigh.
They are not atoms. Atoms have protons in the nucleus, and electrons orbiting them. Neutron stars are just tightly packed atomic matter, mostly neutrons, since during gravitational collapse, most of the electrons crash into protons, turning protons into neutrons. Atoms are held in place by nuclear and electromagnetic forces, neutron stars are held in place by gravity, so they have completely different properties and structures.
@CandelaCenter Also I have a personal belief that calculus is wrong and I don't want to waste time learning it. Calculus works by cutting up things into really small bits to make the errors insignificant. But it still is an approximation of say the surface area of a circle even if its a really good one. I am waiting for another Einstein to due to calculus what Einstein did to newton's laws of gravity. I think that That is the key to the problem of FTL flight.
don't wanna sound like a smartass, but I wouldn't cut the speaches of the two professors together, but show them one at a time. I got confused a few times and had to rewind =)
@CandelaCenter ok then I will watch some of you videos and start conversing there. It may take a little while though I am in the middle of reading a good book Destroyermen Firestorm by Taylor Anderson
They didn't even talk about black holes. They really missed a great opportunity to try to mind-blow people with the densities of micro black holes vs supermassive black holes. Pretty sure that would shocked people far more than the stuff they told in this video.
@superdau I assume she would turn and fire chalk at you, inviting you to teach Density in today's class....it wont matter if you're right, never even act like you caught an Astrophysicist in error, especially first year. Between you and I, she could have said "meters cubed" or something else, to be correct, but the 2nd dimension keeps calling out to her.
+Dane Alexandre Earth core is about 13 times as dense as water. Comparable with lead or mercury (in between those 2). But the earth is the most dense planet of our solar system and also far more dense than the sun (on average).
+VoltzLiveYT Off memory we already /do/ know they /aren't/ singularities, they're just treated as such due to their ever-decreasing size. (Supposing time works similarly near the center of a black hole, /allowing it/ to continue to shrink the same way). As for OP, the density if everything stays the same as before it /becomes/ a black hole (IE, shrinking), is a decreasing variable and not a constant.
OK, so if it's like a giant nucleus of an atom will electrons orbit it? In this way, do we have an honest chance of seeing the element jumbonium for real in the universe?
bruinflight The subatomic particles will never be that large. Though i suppose if you were to cobble some planets together to look like an atomic nucleus and set some moons orbiting it on different planes you could make something resembling an atom on the cosmic scale...
benaldo138 SEE! This is exactly what I want. If we can get something like this to happen, then we could make giant photons of light when the planets skip back and forth from various orbits. Then, planets would act more like waves instead of particles too, and we could really be in many places, from an orbital point of view, at the same time. The implications are enorgantic. I mean, this is particle super-duper-symmetry at its finest. Dirac, roll over.
Thing is, planets don't behave like subatomic particles. they behave like planets. The problem with applying quantum principals to the macroscopic world is that the macroscopic world doesn't obey quantum physics... Just like how quantum phenomena don't follow classical mechanics. There's a disconnect.
10^-27 what? (0:20) Presumably kg/m^3 but why not c^5/ħG^2 ... or scruples per kilderkin? ... Ah, right ... sorry; I didn't have my thinking cap on. It's obviously 10^-27 elephant masses per cup.
+saiyaniam Atoms do have a crushing limit ! All matter have crushing limits ! Why is that?? Because of the wave function of particles ! U simply cannot shrink 2 electrons high enough because the way that electrons move around atoms are in a wave function! So there is a probability that if 2 electrons are shrink enough to eventualy share the same space in a moment of time, and by doing so they are basicaly breaking the Pauli principle exclusion. And so u get the breaking of the electrons from the atoms , and by doing that there is no balance in his core , and eventualy protons and neutrons are faceing the same dilema, and they breakapart too into quarcqs, pioni, gluoni, etc.
