Neutron Star

Why would I take credit for the TOV equation? It's Tolman, Oppenheimer, and Volkoff. No sense in writing anything down for crackpots, you, since the likelihood you'll give a shit is nil. The likelihood you'd be able to understand is < nil. You've made that perfectly clear. Prof. Bennett's post is the only post worth reading in this entire thread. To bad you can't seem to understand what he wrote down for you.

 

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My pleasure, guys. More reviews from the experts:

 

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Thanks also tashja, although I'm not sure its going to make much difference with the attitude of Rajesh.

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One can live in hope I suppose.

 

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Spamming is when you post the same exact thing over and over! So how many times have you posted the following.., word for word?

But here is the real kicker! The above is a challenge not a question... Just adding question marks does not a question make...

You should pay special attention to the following two lines in Professor Duez's comments. (I think he was being kind!)

Personally I find it hard to make any sense out of most of what you post.

 

Prof Benjamin and Prof Matt, both have echoed the sentiments of Prof Hamilton and Prof Bennett....But as I said the original objection by both Prof Hamilton and Prof Bennett question and opens the Pandora's Box around formation of BH.

Prof Hamilton Objection

He says that BNS would contradict causality (sound speed > c)....I am saying it will not..

1. The Density of a Neutron star is around 10^15 Units, at around 10 Kms radius and say 1.5-2 Solar Mass.

2. The Density of this mass if compressed till (Extreme Packing of Neutrons Rp = 7.5 Kms) will be around 10^17 Units.

3. Since there is no consensus on the state of matter up there, so finding out the exact point where the causality stands violated is difficult, (Some calculations it is 1.1 Rs, some other it is 1.3 Rs), so we can safely say that the worst condition for causality violation is when the core is at = Rp (Neutrons extremely rigidly packed).

4. In the paper the first range (from 1.4 to 2.65) gives a condition where R(n) > R(p) > R(s), in this case a stable Neutron Star is formed because the core is still above R(p), but it cannot collapse to become BH because R(p) > R(s) and causality would be violated if core becomes < R(p).

5. Now if we take a core of 10 Solar Mass, which is expected to form a BNS ( >3.24 ), then for this R(s) = 30 Kms and the point where the causality would be violated is at R(p) = 13.8 Kms.

What I concluded is that NDP would give a stability to this core somewhere between 30 Kms - 13.8 Kms, well before the causality violation point.......13.8 Kms is the NDP overcome point, beyond which BH.

So Prof Hamilton's objection point has not reached yet, and this objection is not applicable.


Prof Bennett Objection

His objection is that no surface can exist inside R(s) because for surface to exist pressure = 0 at surface and he calculated that for r < Rs, such condition cannot come. Now a simple counter question is that then how any sort of surface can be expected for a BH mass anywhere between r = Rs to r = 0....Material just vanished ?? No vague reference to QGT would suffice. But to counter his point on more prudent points....

6. Original TOV and Hydrostatic balance equations give an upper mass to NS = 0.7 Solar Mass......An NS of around 1.9 is found.

7. These equations coupled with relativistic approach yields a stable radius of core around 4/3 Rs and 9/8 Rs (two different approaches and solution > R(s)), so how the core even compress to R(s), leave aside getting to r = 0 ?

8. These equations yield bad results without considering the spin of NS, which prof Bennett has not shown.

9. No consensus on equation of state as on date, and a relativistic approach around EH, is derived based on boundary conditions at r = Rs, so obviously it would give a result as shown by prof Bennett..

10. Take the example 10 Solar Mass core, suppose it somehow managed to pass 4/3 Rs and 9/8 Rs, and fell to r = Rs and started its further journey towards r = 0, then at r = 13.8 (Pt #5) above, it will encounter start of causality violation (Prof Hamilton Objection is right on the face in the formation of BH), so how it can collapse to r= 0 ??

following thing may happen for a core once it falls below Rs

a. Vanishes to r = 0 (Violating Causality on the way) and become the BH.
b. Stabilize as BNS (between 30 - 13.8 Kms for a 10 Solar Mass Core)
c. Explode at around r = 13.8 Kms to save on Causality violation.
d. Something happens between 30-13.8 Kms to save on causality violation.
e. Something else starts happening when r tries to go below 13.8 Kms

professors say that (b), (c), (d) and (e) are all untrue but (a) is most likely, and relativity also fails at that point. So if relativity fails at r = 0, it might as well fail from r = Rs....And what kind of relativity we are talking about inside EH ?? EH inside is an absolute nogo place for outsider observers, its relative to nothing...

To me the most sensible options are one or all of (b), (d), (e)..........cheers !!

 

Many people find it hard to understand what I say, but after a prolonged no-no-no they fall in line...For example, Paddoboy, after a few months of singularity at Planck's level chanting...fallen in line.

 

How did you figure it out that I am crediting TOV to you ??

 

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excuses, excuses, excuses, It's my theory, and I'm not letting go!....You are all ganging up on me, I'm right, I'm never wrong, your links are no good, more excuses, excuses, excuses, GR is wrong, I'm right... BHs don't exist, just BNS,...I'm the expert...I've been at it for 12 months...you're all crazy......I don't need any references, it's my word and I'm right....I'm right I tell ya!!!!!

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hohum..............

Other then yourself, I doubt anyone is really listening to your pretentious "back against the wall" defence of such nonsense.

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Of course as any favourable peer review comes through, you will let us know, won't you?

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It's also rather embarrassing seeing you giving me so much credit with a mention in most of your posts.
I am though rather satisfied as being a prime instigator in exposing you for what and who you are.

 

For a change discussion on this thread called for some scholarship demonstration by involved members. I feel sad to see that except Q-Reeus, none of you (You, Brucep, origin, OnlyMe) know any thing substantial about subject in hand. All of you acted as instigators of varied degrees (you being the prime), not as learners of astrophysics. You guys are like those insects in the potential well, who helplessly wander around and vanish never try to jump out..get up guys, feel for your interest and hobbies even at this age....do something instead of instigating only.

 

Stop it Rajesh, you'll have me in tears

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Thats funny !!

 

Are you purposely trying to be ironic? Talk about not learning, 2 professors have told you your idea is wrong and you dismiss them. This is a joke and it belongs in the pseudoscience section

 

You're welcome, Paddo.

Raj: Prof. Link addresses your questions/comments below:

 

Thanks, Tashja, and if possible convey my regards to Prof Bennett for taking his time off and responding in most lucid and clear manner...


However, I am surprised why Q-Reeus in earlier post shown ignorance about my figure 4/3 Rs, and also prof Bennett made following comments to my reference to 4/3Rs (along with 9/8 Rs)

.......I don't understand this statement. The point is that a neutron star must have R>(9/8) R_s to be stable. By how much R exceeds R_s depends on the equation of state. Perhaps you are asking about how one makes a black hole? Black holes are made differently than neutron stars. In a Type II supernova, for example, a black hole is produced because the core is compressed during the explosion to within its stable radius. Then no equilibrium is possible, and the core collapses to a singularity...........


Pl refer the link below, at Page # 157, both these terms are derived at Eqs # 6.3.11 & 6.3.12, I find 4/3Rs more realistic as it is derived from non infinity considerations...(and also conclusion at 6.3.13)

http://ads.harvard.edu/books/1989fsa..book/AbookC06.pdf

Two more question if you can get response from Prof Bennett:

1. Let us say we have a NS of around 1.6 Solar Mass and 10-12 Km radius, can it become BH by accretion ?
2. Is there any upper limit on the initial BH mass ? That is without considering the accretion once the BH is formed.

 

Í'm not the Professor but I'll answer those questions......
[1] Yes.
[2]There is no upper limit on any BH mass.
Once the N/S has accreted enough mass to overcome NDP, it will collapse past its Schwarzchild radius and become a BH.
For your 1.6SM N/S, that Schwarzchild radius would be about 5kms.
http://www.aoc.nrao.edu/~smyers/courses/astro12/L18.html
Note that degenerate objects such as white dwarfs and neutron stars shrink as mass is added, as the increased gravity compresses the matter. The radius of a 1 Msun neutron star is around 10km, while the radius of a 3 Msun neutron star is about 9km. However, the Schwarzschild radius for 1 Msun is 3 km, and thus for 3 Msun it is 9km. Thus, a 3 Msun neutron star would be within its own Schwarzschild radius and would be a black hole (and we would never know whether it had a neutron star structure). This is the Schwarzschild limit for neutron stars. Calculations show masses greater than around 3 Msun will collpase indefinitely, as neutron degeneracy cannot withstand gravity. This is similar to the Chadrasekhar limit for white dwarfs. Barring any other sort of degeneracy or quantum effect, such a mass could collapese to infinite density, but we would never know since it is within the event horizon (unless you would wish to journey there).

None of that though has any bearing on the simple fact that what your paper in effect is saying, is that GR is invalidated and what you hypothesize is impossible.

 

It is hopeless paddoboy because as it has been said before arguing with a crank is useless. RajeshTrivedi is firmly in the pseudoscience area and no amount of counter evidence will sway his beliefs. Too bad, he seems like an intelligent fellow but his own arrogance is going to limit his potential.

 

Scholarship is a big word Rajesh. Way bigger than what's between your ears. This is a little scholarship from me to you. It will give the tools to answer several questions I posed you which you intentionally ignored because you don't have the scholarship to even attempt to answer. Find r_ouch and Tau_ouch for the 'trapped behind the event horizon' neutron star as it falls to complete annilation at r=0. Explain why GR makes these predictions.
http://www.sciforums.com/threads/a-...ree-falling-bodies.142718/page-2#post-3234617

 

You're welcome, Raj. I have conveyed your regards to Prof. Link. Thank you for your commendable attitude toward all the professionals that have participated in this thread. Below is Prof. Link's reply, and the review of a distinguished expert in the field of neutron stars.

 

Although I am very grateful for all the responses by Professors, It has been a real good understanding on some finer aspects...still with diffidence and respect I request you if you could further request the professor Bennett to be kind to explain the following questions again...

To prof Bennett, My questions in post # 215

1. When I asked about formation of BH via mass accretion by NS which is around 1.6M and of radius around 10 Kms......I meant the following.

If this happens, then certainly the core on overcoming the NDP, would pass through 4/3Rs (or 9/8Rs) before getting inside Rs........that means the causality is violated outside EH ? Although you says that it will give a gamma ray explosion, is it because of this violation limit ? And if so then is there a chance that not all NS' (who can acquire mass) will become BHs, the explosion could be severe enough to disintegrate the NS completely without forming BH ?

2. When I talked of higher limit on the BH mass....I was referring to formation BH mass (not the acquired mass through accretion)...

If I presuppose that a sufficiently large Mass core will become BH, directly by surpassing EDP/NDP, then the stage of causality violation will come inside Rs, (even stage of NDP overcome will come inside Rs), so how a BH is formed, because there will certainly be a violent explosion inside the EH in the process, and we have no means to know that......the disturbing point is that for large mass cores the causality violation point may appear inside during its collapse beyond EH, so to avoid this the original collapse formed BH must have an upper mass limit or it should explode inside EH....

(The calculations by which we arrive at figures of 4/3Rs and 9/8Rs, appears to be general.....but since density at Rs is inversely proportional to M^2, it is apparent that sound speed>c may not come at or >Rs, it may be at < Rs for higher mass cores.)