Yet, contrary to what one might think by reading Dr. Baird, how much curvature a fixed invariant mass spaceship causes to spacetime, most definitely depends on its velocity.
The spaceship is at rest in its own frame, so its velocity is zero. It makes no sense to refer t the velocity of something without referring to what that velocity is relative to, in which case the situation is recipricol and you can take either to be at rest or neither to be at rest relative to something else.
If you had read my post, you'd know that I frequently and explicitly talk about "barycentric coordinates" and "barycentric coordinate system".
Why do you so obstinately refuse to read the entire thread? I find that gross, selfish, and pretty much a signature of an idiot. Prove me wrong.
Part of the difficulty I'm facing here is the lack of valid examples geared toward a layman.
I'm not a layman. I have a PhD in nuclear physics. Feel free to do this using differential geometry.
I'm not trying to show examples to you; I do not doubt you know this stuff. That is why I asked you to point out any errors in my initial post; if you were to describe any, I would definitely trust you enough to seriously examine my claims, and either admit error and fix it, or explain why I believe I am not in error. I do not extend that trust to Dr. Baird, because the plain reading of their text indicates they are either completely wrong, or being nitpicky about the terms used ("relativistic mass", which is just an useful analog for those working with a Newtonian mindset) and failing to point it out and therefore leading non-physicists completely askew in their understanding (in particular, that momentum does affect spacetime curvature; a plain reading of Dr. Baird's question and self-answer makes non-physicists believe the opposite, which is the error that bugs me).
I am trying to explain things to the original asker, and anyone else who reads this thread and sees things the same way.
The reason I am using the words I am using, is because I'm trying to help them understand the situation in terms they can understand. I am directing my words to laymen. That does not mean I think you are a layman.
You just swooped in from the side, didn't read the thread from the start, and just started to nitpick on me, without realizing I am the one here trying to describe the model that currently best matches reality. Then you get offended and demand I start using math notation you're familiar with, because you think I'm offending your sense of grandeur. Get real, and read every message in this thread, before posting again; you're making yourself look like a poser who knows the lingo but not much else, not a scientist.
As to myself, I don't have a PhD yet, and probably never will (the university politics have become too crazy for me), although I do have taken the courses needed for a PhD in physics (my specialty being computational materials physics), plus probably enough in CS for a side MSc. (PM or email me, and I'll let you know my real name, and provide you my course records. It isn't magnificent - the GPA isn't
that good, except in the deeper, specialized courses, but shows I am being honest here.) I prefer to stick to classical models (because they are lightweight enough to compute complex enough systems to have practical use cases I'm interested in, like material degradation in fusion reactor walls and raw natural gas turbines), but have done enough research into general relativity to understand the issues of properly simulating e.g. galaxies without resorting to rough approximations. I do my best work when supporting other researchers, maintaining computing clusters and developing simulators, visualisation, and sonification of (especially massive) simulations. I am not a theorist, because I am not that good in math (I really need Maple, Sagemath, or Maxima to do proper work with field equations, or really, anything to do with differential calculus), but I have in the past successfully described complicated physical systems and processes to laymen, giving them a solid base for correct understanding; and that is what I am trying to achieve here. Not precise technical correctness, but to provide the laymen – not you, the asker and others reading this thread, you oaf! – a better picture of the reality involved here.
I have also ran an IT company as part-owner and CEO for a few years, but found am not suited for the scammy world of IT business. That, and previous unfortunate workplace choices have broken me utterly. I suffer from recurrent severe depression, and although it is pretty well under control now, I still cannot handle stress at all, physiologically. I get immediate painful rashes from stress (histamine reaction from stress hormones), and there is still something seriously wrong with my brain pathways, as stress measurably decreases my problem-solving skills.
I am a broken, burned out husk of a man, and not something you should see as a competitor or challenge to your PhD.
Now, please, re-read all posts in this thread, especially focusing on my first post (fourth in the thread, I believe). Then, if you still believe I have made any mischaracterizations or errors in my descriptions that leads laymen astray – again, I don't care if those who know this stuff disagree with the terms I use, because the end goal is not technical correctness, but a robust overall description at the layperson level that leads to
correct understanding –, post them or send me a PM; I will consider them throughly, and highly appreciate any suggested corrections, and publically admit any error and correct them if you show any. (Just look at my posts in other threads; I do that all the time. I am often wrong, and will gladly admit to being wrong when shown proof, and be grateful for letting me know. Truth is
that important to me; way more important than my own ego. How about you?)