Talk:Neutron star
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"Gravity" section example
The example says that an object falling from 1 meter height would reach the ground at 1400 km/s. The cited source seems to be using "(2*1*9,8*10^11)^(1/2)", which checks out. However, I think there is a typo in the source: the equation for a falling body is "v = (2*g*d)^(1/2)", as per Equations for a falling body#Equations, and "[t]he gravitational field at a neutron star's surface is about 2×10^11 times stronger than on Earth", as per the section introduction. So there should be two 2's in the source's equation: (2*1*2*9,8*10^11)^(1/2) = 1980 km/s. 85.216.152.106 (talk) 19:01, 7 April 2025 (UTC)
- Blogs tend not to be reliable sources. Lithopsian (talk) 20:51, 7 April 2025 (UTC)
Think of making a single list of neutron star.
I had see there are many things about neutron star but not seen a list of neutron stars including Pulsar and magnetars. Is this a great idea. Abdullah1099 (talk) 16:27, 19 July 2025 (UTC)
Non-relativistic does not mean "slower than c"
Every massive particle moves slower than the speed of light. If you'll accept Wiktionary as an authority here: "1. Not relativistic; classical, Newtonian. 2. Not moving at a speed comparable to the speed of light." Meanwhile, "relativistic", sense 2: "(physics) At or near the speed of light." Or Merriam-Webster, "nonrelativistic", sense 2: "of, relating to, or being a body moving at less than a relativistic velocity", and "relativistic" sense 2: "moving at a velocity such that there is a significant change in properties (such as mass) in accordance with the theory of relativity", which two of the sources clarify: "a significant fraction of the speed of light" and "moving near the speed of light".
The current state of the article explains "non-relativistic" as "moving slower than the speed of light", which would imply that every relativistic neutron is also non-relativistic. The phrase "much slower" may be "linguistically imprecise" but it is not an improvement to give a blatantly incorrect definition! It would also be "precise" to say that nonrelativistic means "moving at three times the speed of light"; that doesn't make it a good gloss.
The reason for "imprecise" glosses of "non-relativistic" is that "non-relativistic", like "short", is an inherently imprecise word. It would be an error to gloss "short person" as "a person whose height is less than ten feet", even though it would be precise.
ZergTwo, please stop inserting glosses for technical terms that are directly contrary to how the entire field of physics uses the term. A particle moving at .99999c is not "non-relativistic"; ask any physicist, any textbook, or consult the sources I named above. Patallurgist (talk) 23:56, 4 November 2025 (UTC)
- Yeah, when I was in school (BA engineering physics), we would use 0.1c — 10% — as a convenient way to look at slight relativistic effects. The speed of light is essentially a singularity, and the closer you get to it, the more distorted stuff gets. The distortion factor is gamma 𝜸 = 1/sqrt(1-v²) if you take your speed s and divide it by c for v = s / c, which is what we always did, otherwise the c gets in the way of doing a derivation. (The 'gamma' function 𝛤(x) is unrelated.). So here are some examples:
- at .1 c then 𝜸 = 1.005, almost no distortion
- at .3 c then 𝜸 = 1.05, just a little distortion
- at .7 c then 𝜸 = 1.4, noticeable
- at .9 c then 𝜸 = 2.3
- at .99 c then 𝜸 = 7.1
- at .999 c then 𝜸 = 23.4
- at .99999 c then 𝜸 = 224
- Yeah, when I was in school (BA engineering physics), we would use 0.1c — 10% — as a convenient way to look at slight relativistic effects. The speed of light is essentially a singularity, and the closer you get to it, the more distorted stuff gets. The distortion factor is gamma 𝜸 = 1/sqrt(1-v²) if you take your speed s and divide it by c for v = s / c, which is what we always did, otherwise the c gets in the way of doing a derivation. (The 'gamma' function 𝛤(x) is unrelated.). So here are some examples:
- so you can see that a lot more is going on towards the higher end. OsamaBinLogin (talk) 19:57, 25 December 2025 (UTC)
Try to remove some text in the first section
Its way too long maybe have an indivudual section about the stars facts longer to the bottom Upper zero (talk) 10:58, 21 January 2026 (UTC)
- How about that? Quick and dirty, could probably do with some copy-editing, there are bound to be some flow issues from bulk-moving that much text. I think the size of the lead is about right now, even for such a long article. Lithopsian (talk) 16:44, 21 January 2026 (UTC)
RX J1856.5−3754 as a thermal object
Does anyone know if the reference to RX J1856.5−3754 in the second paragraph is correct? The sentence seems to be saying that it's an example of a neutron star thats cooled down to an infrared object, but as far as can tell it's really still a hot x-ray/UV emitter.
Is this taking about that same object: https://www.astro.sunysb.edu/fwalter/NS/ns.html
(talk) 16:07, 1 March 2026 (UTC)
- Yes, 430,000K is not your normal toaster oven. I changed the intro content. Johnjbarton (talk) 18:17, 1 March 2026 (UTC)