Many times I've asked what kind of matter is a neutron star and never got a clear answer, until now. Nuclear pasta is the perfect analogy for a layman. And the diagrams at 37:54 showing how nuclei deform and stretch as density increase seems to say "leave your standard notions of physics at the door, we're going into uncharted territory".
You're welcome. If you want more resources, then take a look at my personal website: www.jasonkendall.com/WPU/AstronomyLectures/07/ Lots of supplementary material for you.
Imagine witnessing the collapse of a massive star as it gives birth to a neutron star. This all happens so quickly you wouldn't be able to process it with your eyes. But imagine filming it, and slowing it down so you could view that collapse in stages!
Then imagine being there to witness such an event in a ghostly form , a form that would be impervious to any kind of destruction , a form that would be able to witness all wavelengths and slow or speed up time as you wished so you could ride the collapse of the core itself while being able to fully understand the physics involved without in the least being hurt........ WOW ....... All of those neutrinos being released and the rebound off the neutron core in that moment pushing all of that mass and energy away from what's left of the star . Then backing out and witnessing the nebula in all of it's glory as it is bombarded with all of that intense radiation , witnessing through a higher powers eye's the creation of everything that ensues giving birth to new stars with heavier elements spawning solar systems and new life........ , The creation of everything. What a dream !! I can kind of see it in my mind's eye. 😎
Computer simulations of Stellar core collapses have to simulate rally Taylor instability where lighter material mixes with denser material creating chaotic mixing scenarios. The same phenomenon had to be taken into account when doing calculations for implosion systems for nuclear weapons
I wish I could have afforded to go to a higher education after high school. I would have ate this stuff up from dawn to dusk -- then burnt some midnite oil.
Great vid. I suggest that the comparison of rotational speed of a NS to a helicopter blade is so many orders of magnitude different that a better comparison might be to a CD spinning, or something a lot faster.
Neutron stars are the coolest most sinister stars in the universe on my list. This is awesome! They can spaghettifi you and crush you into a molecule just as a black hole...and these things are very tiny but they can take a big star and ragdoll it in a binary relationship.
Minimum net mass of pulsar is the chandrasekhar limit, 1.44 S.U. Their maximum mass is the net minimum mass of a black hole, the Holiday Limit, 2.88 S U.
Neutron stars and magnetars are my favorite stellar phenomenons because they're literally the limit of seeable matter. It's hard to understand how matter can be crushed down to such a small sphere and maintain it's integrity without exploding. So the singularity of a black hole must be spinning at infinite rotation?
Actually there is a maximum spin rate to a black hole. Angular momentum is a form of energy and contributes to the curvature of spacetime. And as for inside the event horizon, I Am reminded of Groucho Marx. “Outside of a dog, a man’s best friend is a dog. Inside of a dog, it’s too dark to read. “
@@JasonKendallAstronomer Thank you for the reply and clearing that up. I grew up around Star Trek and everything sci fi. Wished I could have had the smart gene, unfortunately crunching numbers was something I couldn't grasp as a young man. I admire the science community. You don't get the recognition you deserve.
@10:26 I am trying to do the math here and not finding the same results! I'm off by a not-so-worrying factor of 2 in one place, and a much-more-worrying factor of ten million in terms of total energy. G_n = 2e11 • G_e G_n ≈ 2e12 m/s² First, isn't the 1400km/s the result of dropping from 0.5m rather than 1m? Given v = a•t 1.4e6 m/s = t • 2e12 m/s² t = 1.4e6 / 2e12 ≈ 0.7e-6 s Integrating v = a • t h = ½a • t² h = ½ • 2e12 m/s² • (0.7e-6 s)² h = 1e12 m/s² • 0.5e-12 s² h = 0.5m Given this, gravitational potential energy and kinetic potential energy disagree by a factor of two: Ep = mGh Ep = 1kg • 2e12 m/s² • 1m Ep = 2e12 kgm²/s² = 2e12 J Ek = ½mv² Ek = ½ • 1kg • (1400km/s)² Ek = ½ • 1kg • (1.4e6 m/s)² Ek = ½ • 1kg • 2e12 m²/s² Ek = 1e12 kgm²/s² Ek = 1e12 J But notably, neither one is even close to the energy of a megaton of TNT, which is 4.18e15 J. Rather, the energy is about equal to 200 or 400 tons of TNT for Ek or Eg respectively. Apparently the sum of nuclear bomb yields is about 3e3 megatons, which makes my energy figures off by a factor of ten million. However, .4kilotons of TNT is only off from the strength of the Hiroshima bomb (15 kilotons) by about a factor of 30. I did also run the calculation and find that it's equivalent to five femtoseconds of the sun's output, or about 1500km² of the sun's surface for 1sec. It was the 5e-15 sec result that left me scratching my head a bit. Of course that's still an insane amount of energy! It's also crazy to me that a mass dropped from 1m will hit the ground in 7e-7 seconds!
UA-cam video feeder bot, you incompetent POS, why did it took you YEARS to suggest me this channel? This is the first video of yours that I stumbled upon and I am in awe. I am positive I'll devour your videos in the coming weeks. Many thanks for what you're sharing and for how clearly you're explaining everything, hats off!
I know. One of the most critical discoveries for physics that should come in the next decade or so will be a well-measured radius is done of say the Crab Pulsar. That will fix in place the equation of state of a neutron star, and give huge amount of information about the most extreme objects in the universe.
20:27 Ay-yi-yi... The discussion of pressures here is very incorrect. I looked quickly through the comments, but no one seems to mention it. Pressure is a measure of force per unit area. the SI unit of pressure is the pascal, which is newtons (force) per square meter (area). You can sum (that is, integrate) total force acting on the surface of a nuclear submarine by multiplying the pressure in pascals X the total area of the sub in square meters, but the pressure itself is not additive. It is the same at every point on the surface of the sub. (Actually, it's slightly greater on the bottom of the sub than on the top, owing to the (salt water) hydrostatic pressure gradient, which is what creates buoyancy! Stiletto heels have high pressure underneath them because the weight (force) of the woman (=mg) is distributed over a very small area... probably less than a square centimeter, and since weight (force) is produced by gravity (you know the formula!), it can only really be applied by women on top of the submarine. But even if you _could_ put women heel to heel to heel all around the submarine applying the amount of pressure indicated, the sub still would *not* collapse!! It is specifically built to withstand this amount of pressure! (It _would_ be crushed, however, if it descended to the bottom of the Marianas Trench). Same problem applies to your other integrations of pressure over the surface of an object. Otherwise very well done and enjoyable video!
If a neutron star cools down to the point that it doesn't glow visible light, what would it look like? I've heard some said it would be mirror reflective like a big polished metal ball.
That's really interesting. First, the universe is likely not old enough for such things to exist. They start off supremely hot, and their surface area is too low to effectively radiate it. But let's assume one exists today. The nature of relativistic effects means that it'll be pretty dark. There would be significant gravitational redshift of emitted light, and it can't get cooler than the background radiation, so the temperature of such an object today is 3K. That means it peaks in the radio part of the spectrum at the surface. The typical gravitational field of a neutron star is large, so that would redshift it down some more. Interestingly, that might make it a photon sink, as it would be cooler than the surroundings thermodynamically, so the photon field would try to "warm it up." That'd leave it actually hotter at the surface than the universe forever, but not by much. So, the thing is pretty dark to begin with. Now if you shine light on an object, the property of reflection depends upon the interaction of that light principally with the electrons made famous by Feynmann's chats on QED. But the electrons in a neutron star that is supercooled to 4K would likely be in a degenerate state. I don't think anyone knows the reflectivity properties of degenerate matter, since we actually can't make that stuff in a lab. So, all I can do is hazard a guess and direct you to graduate-level texts on QED, which I have not read. My guess is that if light is reflected at all under such a state, that old Snell's Law would not apply, and there would have to be some kind of relativistic version of it. My under-informed guess is that such light would be beamed around the circumference in the direction of rotation. Now, such an old neutron star wouldn't be spinning very fast, but I think the end result is that you would not get a reflection back at you (even a reflection to the normal), it would be wildly redshifted, it would be greatly dimmed, would be beamed. That being said, a reflection back to you might occur if you shone the light towards the limb of the star that approaching you as it rotates. So, it's highly likely it'd be dark, unreflective, and would take a staggeringly bright light source just to get a strange reflection back dimly from an odd direction. Also, you'd still not want to be within a lightyear of the thing because of magnetic and gravitational effects. Hm.... Perhaps even that should be taken into account. If the magnetic field stays put, then it's typically quite strong. So, strong that it makes spacetime itself birefringent near the surface. Perhaps wouldn't even get a reflection off the surface, but rather off the bent spacetime due to the intense magnetic field! Fantastic question...
@@JasonKendallAstronomer Wow I didn't expect to get an answer this quick. Thank you so much! I don't think it's possible for it to be transparent since it's surface is still insanely packed with electrons, but I have no idea if it would have a mirror surface or be black or any color. But yeah even if it's mirror smooth the reflection will be very distorted, I didn't think about that. Even the space around it will be distorted and has a gravity lens effect.
@@JasonKendallAstronomer Oh and BTW Thor's hammer isn't made of neutron star material. It's forged with a neutron star's power (probably a few million K or higher). That's the kind of energy you need to melt uru, the magical metal that the hammer is actually made of. Uru maybe very durable and heat resistant, but it's density is in the normal ballpark of metals. The "nobody can lift it" thing is just a magic casted on it. If the hammer thinks you're worthy to wield it, you can lift it. People like Captain America did it in the comics.
Always good to pull in the cultural references, and corrections! Shows you that I'm mostly a DC guy... (Too bad the movies are not as good as the Marvel ones!)
Another quick comment! I did the math to calculate the luminosity of a neutron star a few days before watching this. Indeed even with T⁴, and neutron stars being 1000 times hotter than the sun, the sun is so big (it has 5 billion times the surface area!) that it overwhelms this........barely! By luminosity, my example neutron star of T=10^6 K and r=11km was ~1/5th as luminous as the sun. However, as you point out most of that luminosity comes in the form of x rays. So it is definitely dimmer in comparison than just 20%. I may one day have to integrate over Planck's laws to compare the luminosity in the visible spectrum of our star vs a neutron star! :)
Also thors hammer was made from an exotic asteroid and embwed with a stray cosmic storm (nebula) and odins blessing so only the worthy shall lift it but it contains no actual mass
You are welcome. I hope you’ve had a chance to poke around the rest of the channel. I’ve done the whole gamut of into Astro. Left out the planets since I cannot beat NASAs output.
Wonder how fast a neutron star could spin before it just falls apart We know of some spinning many hundreds of times a second Wonder if that speed limit has been exceeded before That would be one heck of an event
Sychrotron radiation would bleed off energy faster than the mass would accumulate. As the neurton star rotates faster and faster, and gets closer to c, relativistic mass increase comes into play and also removes energy from the system.
There’s an upper limit as the energy density rises there would be pair production in the field which would create particles and carry away energy. And this is only one thing.
it kinda has to exist quark stars actually with quarks you can break a few rules im kinda puzzled why we didnt find any yet could be the most awesome thing yet
Thank you for sharing your knowledge and insight. I am sure you made these videos for your teaching purposes. But sharing with everybody freely the knowledge for teaching is awesome commendable actually there's no words I can say enough of to say how greatly appreciative I am. You've made this understandable and comprehensive to even a Layman can understand I look forward to watching more of your videos.✌👍🍻🍻🍻
White dwarfs have a limit from which then explode into nothingness if they slowly get too much mass like a neighbouring star. Neutron stars can do the same if slowly fed matter and pass the mass limit for neutron stars? Or this stars just cannot disintegrate like white dwarfs?
I very much appreciated this break down of neutron stars but since this video was made it has been proven that a neutron star cannot contain more than 2.17 solar masses before it will collapse and create a black hole.
@@JasonKendallAstronomer I love neutron stars! Thanks for the great info. So when we see these x-rays from NT's were they red-shifted down from gamma rays? Or are they emitted as x-rays but we view them as UV? Or is the effect just not that significant? Is it correct that some of the emissions are being driven by the magnetic field which extend far from the NT and aren't being red shifted as much?
So a neutron star is just a big neutron. So then if I was scaled down to where a neutron of an atom appeared to be 10 kilometers big, from my shrunken perspective, would it still have the same effects on my shrunken self, as a neutron star would have on my normal sized self?
Mjolnir is like lightsabers. a perfect example of the rule of cool. yeah, totally not how reality works, but its just so damn cool I can over look that. Also, nerd moment. Mjolnir was FORGED in the heart of a neutron start, not made of it. And with dying star I always thought it meant they used the heat and pressures of a supernova.
I’d be very interested to see the video of them casually waltzing into a neutron star and blipping on down to the core. If there’s a forge there, one would expect perhaps a nice little mill on the side of a neutron stream. And the bellows could be run by a team of Cheela. Though that would be some oppression.
@@JasonKendallAstronomer to be fair, this is a universe where a guy, completely unprotected, took the full power of a star, all its emissions redirected to one narrow beam, for like 20 seconds. They can still use Hiemdall's teleport beam thing to do the moving though. Still, I prefer to think what he meant is it is made of elements forged in the heart of a dying star. Even if that also includes everything except hydrogen and helium. They just organized them remotely and put the hammer together for the nova to forge it together.
I have a question for you Mr. Kendall. It is my understanding that as a neutron star's mass increases via matter falling onto it that it's diameter decreases. And that the explanation for this is that a type of matter is created internal to the neutron star known as QGP or quark gluon plasma. This substance, it seems to me, would be inherently unstable. Or to clarify this I would assume that the rate of quark interaction would be necessarily higher than anywhere else in the universe save perhaps in a black hole. As such is it possible that higher energy quarks would begin to appear spontaneously within the QGP? If so, then it seems to me that a more stable configuration would be neutrons comprised of charm and strange quarks at the core of such stars. Due to the fact that these neutrons are comprised of much higher energy levels their volume could account for neutron star contraction as they gain mass. I imagine this looking something akin to a central core of charm/strange neutrons, a thin layer of QGP, with an outer layer of standard neutronium and all the various activities and systems that ocurre near the stars surface. A consequence of this might be that black holes are really nothing more than neutron stars that have a Schwarzschild radius larger than the star's circumference. One might, by extension, presume that this process might repeat itself in ultra massive black holes. Where the charm/strange QGP evolves into Top/Bottom neutrons. I do realize that there is a broad arena of physics here that are being glossed over. However, as I imagine it, this might mean that there has only ever been a single black hole within the history of this universe that has generated a point singularity at its core. The common name of which is the Big Bang. I do appreciate that the answer to this would most likely be much more extensive than what could be easily placed in a UA-cam comment section. However would you be so kind as to possibly point me to reference or study material that might allow me to see where the ideas presented above are deficient?
This all seems unlikely. Do you have reference materials that support this idea? Which journal articles support it? Which authors are looking at it? Arxiv references are OK here. In short, while there are issues with the (possible) loss of information at the event horizon, (holographic principle), once things are inside an event horizon, the future of spacetime is "down", as time and space reverse each other. Even pressure itself contributes to curvature. So, once a black hole is formed, whatever goes in is destroyed completely. Please watch my series on Relativity here: jasonkendall.com/Astronomy/03.shtml These topics are always tricky, and it's important to first begin with the current paradigm. Then, find its flaws. These problems are so thorny, that they will, of necessity, defy easy write-ups and definitions. (It's why I stick to the easy bits. They take long enough to communicate.)
@@JasonKendallAstronomer No sir, I don't have reference materials to support this idea. It's just what seems to be what's going on, at least as far as what I can get my own head around. I do understand that these ideas are not part of the current paradigm. But neither was Einstein's idea about being in a free falling elevator, where the occupant would be unable to tell the difference between being in free fall or just floating in space. Ideas don't always fit with our current views. Thought experiments are an essential part of the scientific method. The idea of space and time reversing each other certainly does support the idea of every black hole collapsing into a point or ring singularity. But let's look at why the idea of collapsing into a singularity is thought to be what happens. The cosmic microwave background image or CMB gives us an image that relays a temperature that is so smooth and regular that it is only possible if at the moment of the big bang everything were compressed into a point about the diameter of a single plank length. It follows then that whatever is within the event horizon of any black hole also follows this same pattern. Most if not all of our science surrounding black holes is derived from this premise. However since we also don't observe any other black hole creating big bangs of their own, isn't there something missing in this scenario? What was so special about the big bang that is not true of our run of the mill black holes? The only thing that I can come up with is scope and scale. I.E. the event of the big bang was energetic enough to give rise to all the mass and energy we observe in both the observable universe and what we theorize to be be entire universe. You speak of space and time reversing themselves. Well let's look at that for a moment. Yes without a doubt time dilation occurs in strong gravitational fields. The same is said of objects as they approach the speed of light. And yet when we examine observations of objects approaching the speed of light we see them as if they are slowing down from our perspective. And even though we can't directly observe what happens within the radius of an event horizon the same could be thought to be occurring. When taken to its logical extreme this produces infinite space time curvature, dilations, and collapses everything into a singularity. But we also know that these objects have finite mass, not infinite mass. Since this is true doesn't it follow that it is our maths that are failing to represent reality in these extreme environs rather than the universe conspiring to create singularities that don't follow the same pattern as we calculate were exigent at the big bang? And if we accept that time dilation is not infinite, then time and space reversing themselves is no longer on the table. Take into account also that even though objects, wether in a strong gravitational field(space time curvature) or approaching the speed of light do experience the flow of time differently, the rest of the universe does not. From our perspective these objects seem frozen in time. Or very nearly so. Another issue with thinking of a black hole as having at its core a singularity, is the problem of accounting for the higgs field interaction. We know, or at least think that the higgs field and how particles interact with it give those particles mass. How can this continue if 'nothing' survives below the event horizon? Yes, energy is mass and mass energy and yes they do most certainly simply convert from one form to another. But this doesn't mean that in the absence of particulate matter, I.E. the 'nothing' below the event horizon, that higgs interactions continue. The only evidence that we see is the continued curvature of space time around these objects. We do know that adding energy to an object increases its mass. This has lead to the presumption that energy also produces spacetime curvature. I think it is more fair to say that added energy in an object increases its interaction with the higgs field. But this doesn't indicate that energy itself is itself interacting with the higgs field, only that energy influences matter to more strongly interact. And so if we do not have matter, I.E. the 'nothing' below the event horizon how can energy produce a curvature of spacetime? The short version of this is that any scientific answer that invokes an infinity to describe a finite object must be incomplete in some way. Thus thinking of a mechanism wherein a solid object might produce the effects we see around black holes could open up our understanding of how our universe works in its most extreme environs. It also leads us to the conclusion that the big bang wasn't the beginning of time. That a multiverse is exigent beyond the 96 billion light year diameter we calculate for the universe in which we live. It predicts dark energy, and gives us a mechanism by which a black hole might go nova and thereby create conditions consistent with the big bang. If we look forward in time to the so called heat death of our universe and we presume that the universe is not 'special' then we can imagine that even though matter will eventually degrade entirely into energy that there is also a kind of expanding shock wave flowing into the interversal medium. That the interaction of these shock waves might produce heat spikes that give rise to new matter. And that given the right configuration might collapse down into a black hole that is fed enough mass to eventually go nova and produce its own 'big bang'. This is just how I've come to visualize the overall nature of the universe and how individual 'verses' within a multiverse might be created only to fade into heat death shock waves to eventually repeat the cycle. So not a big bang big crunch style of cyclic behavior but one that much more closely resembles the cycles we see in living ecosystems here on earth.
That's a good question. What I can say is that the current hypothesis and working idea is that as a neutron star forms in the catastrophic last moments of a massive star's life, the core collapses and "freezes in" the core's magnetic field. It's called "magnetic flux conservation". A nice way to visualize it is to think of a classic bar magnet, and its field lines. Any google-able picture will show it. Now take the bar and shrink it, but don't shrink the picture or shape of the field lines. What this means is that the surface area from which the field lines emerge from the magnet will get very small. Therefore, the emerging field lines must get really close together, to allow the "same number of field lines" as was present in the original setup before shrinkage. This is the basic paradigm, but it's still an active area of research, as we can't make conditions like a neutron star anywhere on Earth. Likely it will take knowing quite accurately the radius, mass and polarimetry map of a nearby neutron star, like the Crab, to iron it out. Now, why there is a magnetic field in the first place, is likely because those things just don't dissipate on their own. And you're right, take a ball of neutrons, just as a ball, with no "origin story", and there's no reason a priori for it to have a magnetic field. It's the formation process and subsequent rapid rotation, unknown equation of state, and a high likelihood of wild states of matter that create vigorous interior currents that would then power the field. A couple of researchers go into it nicely here: www.researchgate.net/post/What_is_the_origin_of_the_magnetic_field_of_a_neutron_star
This has puzzled me for a long time since Neutrons are "Neutral" in charge how could they conduct a current. Since we know that a magnetic field is the result of current flow and since there are no electrons in a neutron star how can there be a current flow. How can a magnetic field be generated with out an electric field? When I asked physicists this question I got back silence or an equation that would not fit on a tee shirt. Bill Lewis ex Superconducting Super Collider Laboratory.
@@JasonKendallAstronomer First of all I would like to thank you for taking out the time to answer follow-up question like you did above. Also thank you for presenting an introductory Astrophysics course vs an Astronomy course. Its much more informative. BTW, I am looking for a QCD explanation of what goes on at the core of a neutron star given the current general assumption that some sort of quark/gluon "plasma" exists there. Any chance you could let us know the balances going on in quark degenerate matter?
@@JasonKendallAstronomerI thought also that the superfluidity of the Interior combined with free electrons in moving around creates the magnetic field
Thors hammer is not made from neutron star material, a common misconception. Nobody else can lift it because it has a magic enchantment fixed to it, only a worthey person can lift it. Sitting the hammer on the table is completely plausible due to the weight of his hammer being in comparison to a hammer of same size and density of a normal hammer. Plus....its make believe.
I’m not really sure. That would be 100% dependent upon the equation of state of a neutron star and its interior. And to do that, a high precision measurement of a neutron star’s mass and diameter is required. But that is currently not possible. So it’ll take some work to do. Ten or so years more maybe.
The contraction has gone as far as physically possible The atoms have been crushed together so that the protons and elections merge together so all that’s left is neutrons packed against each other More mass added will only make more tightly packed neutrons until the neutron star is so massive that it collapses into a black hole
My pedandic side can't resist. @ 18:20 you forget a dimension.. It is per cubic meter (m3) not square meter (m2). I am helping yay! Homer would give me a beer. I'd decline like a sissy declaring it is poison for me as an alcoholic but I'd give him a super hug and tell him to wash it down for me asap. Then I'd drive us to fetch supplies for a nice tv chill evening. Thank you.
@@JasonKendallAstronomer Nah I feel you.. as I am.. are just mind blown with the stats of these things and there is no time to or warrant to docus too much into measly m2 or m3 details anyone can see is ok. Also good to make some errors for students to fix to see if they are paying attention. Excellent lecture. Thank you so much. Have a goood one sir. I was sleeping 13 hours and then woke up and chill with big coffee and Gran Turismo and your lecture. Nice first part of the day indeed. 🖖🐺👍
Yes, but it's not as important as electron degeneracy pressure in white dwarfs. Due to their lower mass, the wavelength of electrons is longer, so quantum effects appear first for them, and dominate the interactions of a highly-compressed, normal-matter gas.
Wow great video! That made me think about adding mass to Earth, over time like by mining asteroids and bringing back all that space rock. How much would Earth's gravity change and would their be measurable time dilation at some point?
Thor's hammer does not move due to magic...not mass. I know...fiction but they tried cuz if it was that massive all sorts of problems accrue so they made it "magic" not move.
That's a whoops. But, the electrons in a neutron star's magnetic field, can easily approach the speed of light, especially in the extreme field of a magnetar. When it's a situation of electron or neutron degeneracy, then yes, we do have the hard limit of c for the phase space of the electron (or neutron) pressure, which leads to interesting results...
I'm sure, if you would eat just a bit of neutron pasta, there would be lots of ketchup pretty everywhere. :) Btw thank you for you awesome videos. I need to write it now, because after a while, you'll have thousands of subscribers, and you will not notice my comments anymore in the comment spam.
Electrons are ''pushed'' into them causing the charge to become 0.thus turning them into neutrons. Atleast that's what my non-physicist eyes read, i'm sure it's a little more complicated.
That's right. Sometimes the wheels of progress leave some sticks-in-the-mud behind. Ah, the joys of Flat-Earthers. They just don't know when they've been Left Behind in the Knowledge Rapture.
Wheeler has a long bit in M.T.W. about "Geons", his name for he KugelBlitz. BTW, when my mother was a young girl, a thunderstorm created actual ball lightning that bounced around her room. It came right through the wall without burning anything and left the same way.
Many times I've asked what kind of matter is a neutron star and never got a clear answer, until now. Nuclear pasta is the perfect analogy for a layman. And the diagrams at 37:54 showing how nuclei deform and stretch as density increase seems to say "leave your standard notions of physics at the door, we're going into uncharted territory".
So many 6 minute videos on subjects like this, I’m glad you actually explain in detail what’s going on inside Stars. Thankyou for this series.
You're welcome. If you want more resources, then take a look at my personal website: www.jasonkendall.com/WPU/AstronomyLectures/07/ Lots of supplementary material for you.
You are a gifted presenter -- clarity without too much technicality for the general public. T.
Yes, this is by far the most informative video on neutron star I've seen so far..much thanks
These things, absolute beasts, are just mindboggling... truly stunning objects
Imagine witnessing the collapse of a massive star as it gives birth to a neutron star. This all happens so quickly you wouldn't be able to process it with your eyes. But imagine filming it, and slowing it down so you could view that collapse in stages!
Hopefully soon
Then imagine being there to witness such an event in a ghostly form , a form that would be impervious to any kind of destruction , a form that would be able to witness all wavelengths and slow or speed up time as you wished so you could ride the collapse of the core itself while being able to fully understand the physics involved without in the least being hurt........ WOW ....... All of those neutrinos being released and the rebound off the neutron core in that moment pushing all of that mass and energy away from what's left of the star . Then backing out and witnessing the nebula in all of it's glory as it is bombarded with all of that intense radiation , witnessing through a higher powers eye's the creation of everything that ensues giving birth to new stars with heavier elements spawning solar systems and new life........ , The creation of everything.
What a dream !! I can kind of see it in my mind's eye. 😎
Computer simulations of Stellar core collapses have to simulate rally Taylor instability where lighter material mixes with denser material creating chaotic mixing scenarios. The same phenomenon had to be taken into account when doing calculations for implosion systems for nuclear weapons
Hey man, great series! Be proud of what you're doing! 😄
The most comprehensive video on neutron stars I've seen.
Thanks!
Crab Nebula Neutron Star: Birthplace of the Flying Spaghetti Monster
(awesome presentation & lecture!)
Thank you. Much appreciate the physics of the Neutron star the way you explained it.
Thanks!
You, talking about pasta.
Me, getting hungry for some pasta.
23:50 I suggest to call a standard particle with magentic field: Teslacle.
Co-sign😁
I wish I could have afforded to go to a higher education after high school. I would have ate this stuff up from dawn to dusk -- then burnt some midnite oil.
You got the internet boss. You can literally learn everything for free. Check out MIT OCW
Yep. Get a good telescope and check out some of the stuff he's talking about
You're with us in spirit. Cheers
Great video. Best one I’ve seen on neutron stars yet.
Glad you enjoyed it!
The time frames in the universe are mind boggling. Billion + year lifespans.
Great vid. I suggest that the comparison of rotational speed of a NS to a helicopter blade is so many orders of magnitude different that a better comparison might be to a CD spinning, or something a lot faster.
thanks for making the effort in making these vids
Neutron stars are the coolest most sinister stars in the universe on my list. This is awesome! They can spaghettifi you and crush you into a molecule just as a black hole...and these things are very tiny but they can take a big star and ragdoll it in a binary relationship.
Pulsars, blazars and neutron stars are so much fun. They're powerful for being so small.
this video goes hard af fr doc!
Minimum net mass of pulsar is the chandrasekhar limit, 1.44 S.U.
Their maximum mass is the net minimum mass of a black hole, the Holiday Limit, 2.88 S U.
I really like your videos. Perfect combination of science and entertainment for me. Thank you :)
Neutron stars and magnetars are my favorite stellar phenomenons because they're literally the limit of seeable matter. It's hard to understand how matter can be crushed down to such a small sphere and maintain it's integrity without exploding. So the singularity of a black hole must be spinning at infinite rotation?
Actually there is a maximum spin rate to a black hole. Angular momentum is a form of energy and contributes to the curvature of spacetime. And as for inside the event horizon, I Am reminded of Groucho Marx. “Outside of a dog, a man’s best friend is a dog. Inside of a dog, it’s too dark to read. “
@@JasonKendallAstronomer Thank you for the reply and clearing that up. I grew up around Star Trek and everything sci fi. Wished I could have had the smart gene, unfortunately crunching numbers was something I couldn't grasp as a young man. I admire the science community. You don't get the recognition you deserve.
@10:26 I am trying to do the math here and not finding the same results! I'm off by a not-so-worrying factor of 2 in one place, and a much-more-worrying factor of ten million in terms of total energy.
G_n = 2e11 • G_e
G_n ≈ 2e12 m/s²
First, isn't the 1400km/s the result of dropping from 0.5m rather than 1m?
Given v = a•t
1.4e6 m/s = t • 2e12 m/s²
t = 1.4e6 / 2e12 ≈ 0.7e-6 s
Integrating v = a • t
h = ½a • t²
h = ½ • 2e12 m/s² • (0.7e-6 s)²
h = 1e12 m/s² • 0.5e-12 s²
h = 0.5m
Given this, gravitational potential energy and kinetic potential energy disagree by a factor of two:
Ep = mGh
Ep = 1kg • 2e12 m/s² • 1m
Ep = 2e12 kgm²/s² = 2e12 J
Ek = ½mv²
Ek = ½ • 1kg • (1400km/s)²
Ek = ½ • 1kg • (1.4e6 m/s)²
Ek = ½ • 1kg • 2e12 m²/s²
Ek = 1e12 kgm²/s²
Ek = 1e12 J
But notably, neither one is even close to the energy of a megaton of TNT, which is 4.18e15 J. Rather, the energy is about equal to 200 or 400 tons of TNT for Ek or Eg respectively. Apparently the sum of nuclear bomb yields is about 3e3 megatons, which makes my energy figures off by a factor of ten million. However, .4kilotons of TNT is only off from the strength of the Hiroshima bomb (15 kilotons) by about a factor of 30.
I did also run the calculation and find that it's equivalent to five femtoseconds of the sun's output, or about 1500km² of the sun's surface for 1sec. It was the 5e-15 sec result that left me scratching my head a bit. Of course that's still an insane amount of energy!
It's also crazy to me that a mass dropped from 1m will hit the ground in 7e-7 seconds!
great video. thanks. neutron stars are a personal favorite.
This is a Really Great Lecture!!! Love it!! Thank you sir
I love videos like this where the person who makes the video actually knows what they are talking about. Please keep them coming......< Subscribed.
Thanks!
The phrase “catastrophically dense” is fantastic
14:14
Is it spinning fast enough so that the surface gravity at the equator is significantly lower? (as in "Mission of Gravity")
Very cool Jason👍
Really bizarre stars!
UA-cam video feeder bot, you incompetent POS, why did it took you YEARS to suggest me this channel? This is the first video of yours that I stumbled upon and I am in awe. I am positive I'll devour your videos in the coming weeks. Many thanks for what you're sharing and for how clearly you're explaining everything, hats off!
Who cares about Wikileaks and stuff like that? Neutron stars are like the coolest thing in the Universe.
I know. One of the most critical discoveries for physics that should come in the next decade or so will be a well-measured radius is done of say the Crab Pulsar. That will fix in place the equation of state of a neutron star, and give huge amount of information about the most extreme objects in the universe.
Wow these videos are amazing ! 7min into my first video I subscribed, good job !
If you want to see the silly stuff, look here: Television, Radio and Media Appearances ua-cam.com/play/PLyu4Fovbph6eXnuAq-2oyx8kFMwrzR_At.html
Great video. Despite dissing Thor. Blasphemy!
Just discovered your channel! Its amazing! I've subscribed!
Nuclear Pasta? Waffles? Lasagna? and also Spaghettification? Are all you astrophysicist on a diet? or something? ;) Good video!
Before a heavy neutron star becomes a black hole, is the star undergoing massive time dilation, since it will, “soon”, be inside the event horizon.
20:27 Ay-yi-yi... The discussion of pressures here is very incorrect. I looked quickly through the comments, but no one seems to mention it. Pressure is a measure of force per unit area. the SI unit of pressure is the pascal, which is newtons (force) per square meter (area). You can sum (that is, integrate) total force acting on the surface of a nuclear submarine by multiplying the pressure in pascals X the total area of the sub in square meters, but the pressure itself is not additive. It is the same at every point on the surface of the sub. (Actually, it's slightly greater on the bottom of the sub than on the top, owing to the (salt water) hydrostatic pressure gradient, which is what creates buoyancy!
Stiletto heels have high pressure underneath them because the weight (force) of the woman (=mg) is distributed over a very small area... probably less than a square centimeter, and since weight (force) is produced by gravity (you know the formula!), it can only really be applied by women on top of the submarine. But even if you _could_ put women heel to heel to heel all around the submarine applying the amount of pressure indicated, the sub still would *not* collapse!! It is specifically built to withstand this amount of pressure! (It _would_ be crushed, however, if it descended to the bottom of the Marianas Trench).
Same problem applies to your other integrations of pressure over the surface of an object.
Otherwise very well done and enjoyable video!
yeah I thought something was amiss too
If a neutron star cools down to the point that it doesn't glow visible light, what would it look like? I've heard some said it would be mirror reflective like a big polished metal ball.
That's really interesting. First, the universe is likely not old enough for such things to exist. They start off supremely hot, and their surface area is too low to effectively radiate it. But let's assume one exists today. The nature of relativistic effects means that it'll be pretty dark. There would be significant gravitational redshift of emitted light, and it can't get cooler than the background radiation, so the temperature of such an object today is 3K. That means it peaks in the radio part of the spectrum at the surface. The typical gravitational field of a neutron star is large, so that would redshift it down some more. Interestingly, that might make it a photon sink, as it would be cooler than the surroundings thermodynamically, so the photon field would try to "warm it up." That'd leave it actually hotter at the surface than the universe forever, but not by much. So, the thing is pretty dark to begin with. Now if you shine light on an object, the property of reflection depends upon the interaction of that light principally with the electrons made famous by Feynmann's chats on QED. But the electrons in a neutron star that is supercooled to 4K would likely be in a degenerate state. I don't think anyone knows the reflectivity properties of degenerate matter, since we actually can't make that stuff in a lab. So, all I can do is hazard a guess and direct you to graduate-level texts on QED, which I have not read. My guess is that if light is reflected at all under such a state, that old Snell's Law would not apply, and there would have to be some kind of relativistic version of it. My under-informed guess is that such light would be beamed around the circumference in the direction of rotation. Now, such an old neutron star wouldn't be spinning very fast, but I think the end result is that you would not get a reflection back at you (even a reflection to the normal), it would be wildly redshifted, it would be greatly dimmed, would be beamed. That being said, a reflection back to you might occur if you shone the light towards the limb of the star that approaching you as it rotates. So, it's highly likely it'd be dark, unreflective, and would take a staggeringly bright light source just to get a strange reflection back dimly from an odd direction. Also, you'd still not want to be within a lightyear of the thing because of magnetic and gravitational effects. Hm.... Perhaps even that should be taken into account. If the magnetic field stays put, then it's typically quite strong. So, strong that it makes spacetime itself birefringent near the surface. Perhaps wouldn't even get a reflection off the surface, but rather off the bent spacetime due to the intense magnetic field!
Fantastic question...
@@JasonKendallAstronomer Wow I didn't expect to get an answer this quick. Thank you so much!
I don't think it's possible for it to be transparent since it's surface is still insanely packed with electrons, but I have no idea if it would have a mirror surface or be black or any color. But yeah even if it's mirror smooth the reflection will be very distorted, I didn't think about that. Even the space around it will be distorted and has a gravity lens effect.
@@JasonKendallAstronomer Oh and BTW Thor's hammer isn't made of neutron star material. It's forged with a neutron star's power (probably a few million K or higher). That's the kind of energy you need to melt uru, the magical metal that the hammer is actually made of. Uru maybe very durable and heat resistant, but it's density is in the normal ballpark of metals. The "nobody can lift it" thing is just a magic casted on it. If the hammer thinks you're worthy to wield it, you can lift it. People like Captain America did it in the comics.
Always good to pull in the cultural references, and corrections! Shows you that I'm mostly a DC guy... (Too bad the movies are not as good as the Marvel ones!)
Another quick comment! I did the math to calculate the luminosity of a neutron star a few days before watching this. Indeed even with T⁴, and neutron stars being 1000 times hotter than the sun, the sun is so big (it has 5 billion times the surface area!) that it overwhelms this........barely!
By luminosity, my example neutron star of T=10^6 K and r=11km was ~1/5th as luminous as the sun.
However, as you point out most of that luminosity comes in the form of x rays. So it is definitely dimmer in comparison than just 20%. I may one day have to integrate over Planck's laws to compare the luminosity in the visible spectrum of our star vs a neutron star! :)
The candela is a base unit for a reason. Do the integral.
Also thors hammer was made from an exotic asteroid and embwed with a stray cosmic storm (nebula) and odins blessing so only the worthy shall lift it but it contains no actual mass
What a cool find. Thanks.
Great learning, thank you!
Amazing video. Thanks.
You are welcome. I hope you’ve had a chance to poke around the rest of the channel. I’ve done the whole gamut of into Astro. Left out the planets since I cannot beat NASAs output.
Is the time dilation on the surface more because of the gravity or the relativistic rotational speed?
This is known as the Kerr Metric. Gravitational red shift for NS are dominant
Thor's hammer isn't made of a neutron star =) A neutron star powers the ringwold which is also the forge where the hammer was created.
Yes. I’ve been duly corrected on this many times. Frigga and Sif have both mocked me at cocktail parties and Odin won’t return my calls.
How would these evaporate over time?
what about syncrotron radiation from the spin i though that was where most of the light in a N star came from.
Wow. The comments here are wildly different than from "People of Walmart". I like it here better.
Imagine all the people. Living for the space. Hooohooohohoho
Or any flat earth video lmao
Wonder how fast a neutron star could spin before it just falls apart
We know of some spinning many hundreds of times a second
Wonder if that speed limit has been exceeded before
That would be one heck of an event
Sychrotron radiation would bleed off energy faster than the mass would accumulate. As the neurton star rotates faster and faster, and gets closer to c, relativistic mass increase comes into play and also removes energy from the system.
Good Video Ty for the quality content :)
Is there an upper limit for the strength of a magnetic field or can it theoretically be infinite?
There’s an upper limit as the energy density rises there would be pair production in the field which would create particles and carry away energy. And this is only one thing.
My sister not know what a galaxy was until she watch Brian Cox on the telly. She five times as smart as me.
Thank you!
Hey Jason Kendall you're a real life legend and a rock star.
Million ways to die in astronomy 😆 that should be a book
I know. I should do a video series on it in astronomy.
Yeah. Why do these lab coated cabals have such a fetish for dying?
Golf ball example is awesome
it kinda has to exist quark stars
actually with quarks you can break a few rules
im kinda puzzled why we didnt find any yet
could be the most awesome thing yet
probably inside the cores of neutron stars
Thank you for sharing your knowledge and insight. I am sure you made these videos for your teaching purposes. But sharing with everybody freely the knowledge for teaching is awesome commendable actually there's no words I can say enough of to say how greatly appreciative I am. You've made this understandable and comprehensive to even a Layman can understand I look forward to watching more of your videos.✌👍🍻🍻🍻
Thanks! Please share me around!
Got a little hungry at the end of this video.
I enjoyed this
White dwarfs have a limit from which then explode into nothingness if they slowly get too much mass like a neighbouring star. Neutron stars can do the same if slowly fed matter and pass the mass limit for neutron stars? Or this stars just cannot disintegrate like white dwarfs?
I very much appreciated this break down of neutron stars but since this video was made it has been proven that a neutron star cannot contain more than 2.17 solar masses before it will collapse and create a black hole.
Hit "subscribe" 5 seconds in to the vid. Looking forward to much more!
Are the x-rays red shifted from the star's gravity?
x-ray's are light, so, yes, any that are emitted close to the surface will experience it.
@@JasonKendallAstronomer I love neutron stars! Thanks for the great info. So when we see these x-rays from NT's were they red-shifted down from gamma rays? Or are they emitted as x-rays but we view them as UV? Or is the effect just not that significant? Is it correct that some of the emissions are being driven by the magnetic field which extend far from the NT and aren't being red shifted as much?
So a neutron star is just a big neutron. So then if I was scaled down to where a neutron of an atom appeared to be 10 kilometers big, from my shrunken perspective, would it still have the same effects on my shrunken self, as a neutron star would have on my normal sized self?
That's heavy man! :)
Actually it’s a whole bunch of neutrons (mostly). It’s more akin to an atomic nucleus with a mass number of 10^57.
Mjolnir is like lightsabers. a perfect example of the rule of cool. yeah, totally not how reality works, but its just so damn cool I can over look that. Also, nerd moment. Mjolnir was FORGED in the heart of a neutron start, not made of it. And with dying star I always thought it meant they used the heat and pressures of a supernova.
I’d be very interested to see the video of them casually waltzing into a neutron star and blipping on down to the core. If there’s a forge there, one would expect perhaps a nice little mill on the side of a neutron stream. And the bellows could be run by a team of Cheela. Though that would be some oppression.
@@JasonKendallAstronomer to be fair, this is a universe where a guy, completely unprotected, took the full power of a star, all its emissions redirected to one narrow beam, for like 20 seconds. They can still use Hiemdall's teleport beam thing to do the moving though. Still, I prefer to think what he meant is it is made of elements forged in the heart of a dying star. Even if that also includes everything except hydrogen and helium. They just organized them remotely and put the hammer together for the nova to forge it together.
I have a question for you Mr. Kendall. It is my understanding that as a neutron star's mass increases via matter falling onto it that it's diameter decreases. And that the explanation for this is that a type of matter is created internal to the neutron star known as QGP or quark gluon plasma. This substance, it seems to me, would be inherently unstable. Or to clarify this I would assume that the rate of quark interaction would be necessarily higher than anywhere else in the universe save perhaps in a black hole. As such is it possible that higher energy quarks would begin to appear spontaneously within the QGP? If so, then it seems to me that a more stable configuration would be neutrons comprised of charm and strange quarks at the core of such stars. Due to the fact that these neutrons are comprised of much higher energy levels their volume could account for neutron star contraction as they gain mass. I imagine this looking something akin to a central core of charm/strange neutrons, a thin layer of QGP, with an outer layer of standard neutronium and all the various activities and systems that ocurre near the stars surface.
A consequence of this might be that black holes are really nothing more than neutron stars that have a Schwarzschild radius larger than the star's circumference. One might, by extension, presume that this process might repeat itself in ultra massive black holes. Where the charm/strange QGP evolves into Top/Bottom neutrons. I do realize that there is a broad arena of physics here that are being glossed over. However, as I imagine it, this might mean that there has only ever been a single black hole within the history of this universe that has generated a point singularity at its core. The common name of which is the Big Bang.
I do appreciate that the answer to this would most likely be much more extensive than what could be easily placed in a UA-cam comment section. However would you be so kind as to possibly point me to reference or study material that might allow me to see where the ideas presented above are deficient?
This all seems unlikely. Do you have reference materials that support this idea? Which journal articles support it? Which authors are looking at it? Arxiv references are OK here.
In short, while there are issues with the (possible) loss of information at the event horizon, (holographic principle), once things are inside an event horizon, the future of spacetime is "down", as time and space reverse each other. Even pressure itself contributes to curvature. So, once a black hole is formed, whatever goes in is destroyed completely.
Please watch my series on Relativity here:
jasonkendall.com/Astronomy/03.shtml
These topics are always tricky, and it's important to first begin with the current paradigm. Then, find its flaws. These problems are so thorny, that they will, of necessity, defy easy write-ups and definitions. (It's why I stick to the easy bits. They take long enough to communicate.)
@@JasonKendallAstronomer No sir, I don't have reference materials to support this idea. It's just what seems to be what's going on, at least as far as what I can get my own head around. I do understand that these ideas are not part of the current paradigm. But neither was Einstein's idea about being in a free falling elevator, where the occupant would be unable to tell the difference between being in free fall or just floating in space. Ideas don't always fit with our current views.
Thought experiments are an essential part of the scientific method. The idea of space and time reversing each other certainly does support the idea of every black hole collapsing into a point or ring singularity. But let's look at why the idea of collapsing into a singularity is thought to be what happens. The cosmic microwave background image or CMB gives us an image that relays a temperature that is so smooth and regular that it is only possible if at the moment of the big bang everything were compressed into a point about the diameter of a single plank length. It follows then that whatever is within the event horizon of any black hole also follows this same pattern. Most if not all of our science surrounding black holes is derived from this premise. However since we also don't observe any other black hole creating big bangs of their own, isn't there something missing in this scenario? What was so special about the big bang that is not true of our run of the mill black holes? The only thing that I can come up with is scope and scale. I.E. the event of the big bang was energetic enough to give rise to all the mass and energy we observe in both the observable universe and what we theorize to be be entire universe. You speak of space and time reversing themselves. Well let's look at that for a moment. Yes without a doubt time dilation occurs in strong gravitational fields. The same is said of objects as they approach the speed of light. And yet when we examine observations of objects approaching the speed of light we see them as if they are slowing down from our perspective. And even though we can't directly observe what happens within the radius of an event horizon the same could be thought to be occurring. When taken to its logical extreme this produces infinite space time curvature, dilations, and collapses everything into a singularity. But we also know that these objects have finite mass, not infinite mass. Since this is true doesn't it follow that it is our maths that are failing to represent reality in these extreme environs rather than the universe conspiring to create singularities that don't follow the same pattern as we calculate were exigent at the big bang? And if we accept that time dilation is not infinite, then time and space reversing themselves is no longer on the table. Take into account also that even though objects, wether in a strong gravitational field(space time curvature) or approaching the speed of light do experience the flow of time differently, the rest of the universe does not. From our perspective these objects seem frozen in time. Or very nearly so. Another issue with thinking of a black hole as having at its core a singularity, is the problem of accounting for the higgs field interaction. We know, or at least think that the higgs field and how particles interact with it give those particles mass. How can this continue if 'nothing' survives below the event horizon? Yes, energy is mass and mass energy and yes they do most certainly simply convert from one form to another. But this doesn't mean that in the absence of particulate matter, I.E. the 'nothing' below the event horizon, that higgs interactions continue. The only evidence that we see is the continued curvature of space time around these objects. We do know that adding energy to an object increases its mass. This has lead to the presumption that energy also produces spacetime curvature. I think it is more fair to say that added energy in an object increases its interaction with the higgs field. But this doesn't indicate that energy itself is itself interacting with the higgs field, only that energy influences matter to more strongly interact. And so if we do not have matter, I.E. the 'nothing' below the event horizon how can energy produce a curvature of spacetime?
The short version of this is that any scientific answer that invokes an infinity to describe a finite object must be incomplete in some way. Thus thinking of a mechanism wherein a solid object might produce the effects we see around black holes could open up our understanding of how our universe works in its most extreme environs. It also leads us to the conclusion that the big bang wasn't the beginning of time. That a multiverse is exigent beyond the 96 billion light year diameter we calculate for the universe in which we live. It predicts dark energy, and gives us a mechanism by which a black hole might go nova and thereby create conditions consistent with the big bang. If we look forward in time to the so called heat death of our universe and we presume that the universe is not 'special' then we can imagine that even though matter will eventually degrade entirely into energy that there is also a kind of expanding shock wave flowing into the interversal medium. That the interaction of these shock waves might produce heat spikes that give rise to new matter. And that given the right configuration might collapse down into a black hole that is fed enough mass to eventually go nova and produce its own 'big bang'.
This is just how I've come to visualize the overall nature of the universe and how individual 'verses' within a multiverse might be created only to fade into heat death shock waves to eventually repeat the cycle. So not a big bang big crunch style of cyclic behavior but one that much more closely resembles the cycles we see in living ecosystems here on earth.
06:07 Electrons, possessing mass, cannot move at the speed of light.
Thats where Magic comes in...
yup. Exactly. Much for the magics.
It’s the fact that they become ultra relativistic, energy is proportional to momentum, and v is indistinguishable from c observationally.
Why does a neutron star have a magnetic field when neutrons have a neutral charge?
That's a good question. What I can say is that the current hypothesis and working idea is that as a neutron star forms in the catastrophic last moments of a massive star's life, the core collapses and "freezes in" the core's magnetic field. It's called "magnetic flux conservation". A nice way to visualize it is to think of a classic bar magnet, and its field lines. Any google-able picture will show it. Now take the bar and shrink it, but don't shrink the picture or shape of the field lines. What this means is that the surface area from which the field lines emerge from the magnet will get very small. Therefore, the emerging field lines must get really close together, to allow the "same number of field lines" as was present in the original setup before shrinkage. This is the basic paradigm, but it's still an active area of research, as we can't make conditions like a neutron star anywhere on Earth. Likely it will take knowing quite accurately the radius, mass and polarimetry map of a nearby neutron star, like the Crab, to iron it out. Now, why there is a magnetic field in the first place, is likely because those things just don't dissipate on their own. And you're right, take a ball of neutrons, just as a ball, with no "origin story", and there's no reason a priori for it to have a magnetic field. It's the formation process and subsequent rapid rotation, unknown equation of state, and a high likelihood of wild states of matter that create vigorous interior currents that would then power the field. A couple of researchers go into it nicely here: www.researchgate.net/post/What_is_the_origin_of_the_magnetic_field_of_a_neutron_star
This has puzzled me for a long time since Neutrons are "Neutral" in charge how could they conduct a current. Since we know that a magnetic field is the result of current flow and since there are no electrons in a neutron star how can there be a current flow. How can a magnetic field be generated with out an electric field? When I asked physicists this question I got back silence or an equation that would not fit on a tee shirt. Bill Lewis ex Superconducting Super Collider Laboratory.
@@JasonKendallAstronomer First of all I would like to thank you for taking out the time to answer follow-up question like you did above. Also thank you for presenting an introductory Astrophysics course vs an Astronomy course. Its much more informative. BTW, I am looking for a QCD explanation of what goes on at the core of a neutron star given the current general assumption that some sort of quark/gluon "plasma" exists there. Any chance you could let us know the balances going on in quark degenerate matter?
@@JasonKendallAstronomerI thought also that the superfluidity of the Interior combined with free electrons in moving around creates the magnetic field
Thors hammer is not made from neutron star material, a common misconception. Nobody else can lift it because it has a magic enchantment fixed to it, only a worthey person can lift it. Sitting the hammer on the table is completely plausible due to the weight of his hammer being in comparison to a hammer of same size and density of a normal hammer. Plus....its make believe.
I don't like neutron stars. Their degeneracy is highly offensive.
the question asked at 20 minuets - wouldn't the earth try to travel to the Hammer. "that's weird?
What is the relativistic volume of typical neutron star? Should be greater than 4/3 pi * r^3.
I’m not really sure. That would be 100% dependent upon the equation of state of a neutron star and its interior. And to do that, a high precision measurement of a neutron star’s mass and diameter is required. But that is currently not possible. So it’ll take some work to do. Ten or so years more maybe.
Dark star crashes
so it has gravity? but no gravitational contraction? im confused?
The contraction has gone as far as physically possible
The atoms have been crushed together so that the protons and elections merge together so all that’s left is neutrons packed against each other
More mass added will only make more tightly packed neutrons until the neutron star is so massive that it collapses into a black hole
nice
Power to stiletto heels!
29:27 Anti Proton alert in the background.
yeah, I do need to clean this up....
My pedandic side can't resist.
@ 18:20 you forget a dimension.. It is per cubic meter (m3) not square meter (m2).
I am helping yay!
Homer would give me a beer.
I'd decline like a sissy declaring it is poison for me as an alcoholic but I'd give him a super hug and tell him to wash it down for me asap. Then I'd drive us to fetch supplies for a nice tv chill evening.
Thank you.
Yeah. I know.... Me speak too fast with coffee excessive..
@@JasonKendallAstronomer Nah I feel you.. as I am.. are just mind blown with the stats of these things and there is no time to or warrant to docus too much into measly m2 or m3 details anyone can see is ok. Also good to make some errors for students to fix to see if they are paying attention. Excellent lecture. Thank you so much. Have a goood one sir. I was sleeping 13 hours and then woke up and chill with big coffee and Gran Turismo and your lecture. Nice first part of the day indeed. 🖖🐺👍
38:52 Hairy?
Aww man I watched this for 40 mins thinking he was going to talk about the acting stars that are going to be in the new Tron movie coming out...
Is there such thing as proton degeneracy pressure x
Yes, but it's not as important as electron degeneracy pressure in white dwarfs. Due to their lower mass, the wavelength of electrons is longer, so quantum effects appear first for them, and dominate the interactions of a highly-compressed, normal-matter gas.
I wouldn't tell a woman in stilettos that she has a million pascals pressure.
Might be hazardous to your health.
Give her diamonds.
im standin next to a mountain
thors hammer is made from a forge powered by a neutron star not out of a neutron start
Una clase excelente!! Muchas gracias por estas explicaciones.
Saludos!
Wow great video! That made me think about adding mass to Earth, over time like by mining asteroids and bringing back all that space rock. How much would Earth's gravity change and would their be measurable time dilation at some point?
I think you would need to add the mass of mars to notice something. witch is insane
I get the feeling he thinks neutron stars are dense.
Yup. I do.
so i have something in common with them. great.
Thor's hammer does not move due to magic...not mass. I know...fiction but they tried cuz if it was that massive all sorts of problems accrue so they made it "magic" not move.
Darn magic gets around things.
6:05 "once the electrons are moving at the speed of light" ...??
That's a whoops. But, the electrons in a neutron star's magnetic field, can easily approach the speed of light, especially in the extreme field of a magnetar. When it's a situation of electron or neutron degeneracy, then yes, we do have the hard limit of c for the phase space of the electron (or neutron) pressure, which leads to interesting results...
Anyone wants a bit of Neutron Pasta with cheese and ketchup on it?
Ketchup? that’s not very Italian
I'm sure, if you would eat just a bit of neutron pasta, there would be lots of ketchup pretty everywhere. :) Btw thank you for you awesome videos. I need to write it now, because after a while, you'll have thousands of subscribers, and you will not notice my comments anymore in the comment spam.
guess its a wave..
Subscribed* 😊
Oh
Hairy pasta stars 😂
So, what happens to the protons?
Electrons are ''pushed'' into them causing the charge to become 0.thus turning them into neutrons.
Atleast that's what my non-physicist eyes read, i'm sure it's a little more complicated.
Not bad at all.
case and point, not only would the earth be flat, but neutron stars are flat too. if it wasnt, how could i see all of it at the same time? 😛
OOF!! The Flat-Neutron-Star lobby under the tutelage of Senator Ludditia Ignorania does not approve your satire. However, the Cheela do.
@@JasonKendallAstronomer progress always has a price, sometimes it must be common sense
That's right. Sometimes the wheels of progress leave some sticks-in-the-mud behind. Ah, the joys of Flat-Earthers. They just don't know when they've been Left Behind in the Knowledge Rapture.
@@JasonKendallAstronomer very enjoyable video. neutron stars are my favorites besides the theoretical quark stars and kugelblitz 😀
Wheeler has a long bit in M.T.W. about "Geons", his name for he KugelBlitz. BTW, when my mother was a young girl, a thunderstorm created actual ball lightning that bounced around her room. It came right through the wall without burning anything and left the same way.
nuclear pasta... lol