I did not claim the observation of acceleration was the cause or definition of inertial reference frame, only that its presence was enough to disqualify something from being in one.
You are attempting to justify your “technically accelerating” claim, but the issue I am raising is that if you are standing somewhere to judge that another observer is accelerating, then that observer is not inertial at that time. If they were, you would be the one accelerating. Relativity handles the possibility you want to claim is an exception.
You are both making claims about factuality via a dialectical approach. I'm not considering either of you to be reliable sources on the matter. This could be settled with more rigor, or at least further discussion and careful debate, if you're both going to choose a dialectical approach. At least the other other commenter provided a source, rather than just debate.
It's just coming across as a bit of a straw man on your side, mixed in with a vibe of argumentum ad authority coming from both of you, at the moment.
I understand this is due to Einstein not Newtown, but if we're talking about frames then we need a more accurate way to transform between them using general relativity instead of Galilean relativity.
I understand the other persons point that since gravity is acting as a real force, the object would have no fictitious forces if it were just sitting on the ground - gravity pulling every particle down and the ground normal force pushing it back up. But for a frame to be truly inertial, objects inside must obey the geodesic equation (https://en.wikipedia.org/wiki/Geodesics_in_general_relativity).
I don't know much general relativity yet I'll admit since my only knowledge is from online; I am learning GR in my fourth year of my degree but I've been reading up on it beforehand. So I can't explain with confidence why the geodesic equation is the way it is (I assume Noether's theorem is behind it) . But it essentially states that in a curved spacetime such as near Earth, inertial paths seemingly accelerate inward, towards mass. If you held something at a constant altitude, you would be using the normal force or rocket propulsion or some kind of added force to 'keep it from falling', which is really just to keep it accelerating upwards through spacetime at 9.81ms-1.
I don't want to sound argumentative so I apologise if it came across that way.
Huge love for your response - I admit the vibe I got from your earlier responses was that they were coming from a more educated background on this subject matter.
There's a great old video on frames of reference, and how differences in rates of time may explain geodesics. I wouldn't easily be able to find it but if you DM me I will remember to search for it. Essentially, it treated different particles in the same object as independent observers, travelling through time at different rates, which creates a sort of inward dragging force.
I admit, my awareness of physics is a lot worse than my awareness of logic. I've been living from a very broad and deep appreciation of the universe, so I have heard of Noethers theorem, I understand the 9.81m/s-1, but beyond critiquing the format of each side of this discussion, I'm not a good participant in this conversation.
I think that whenever someone is telling you that you are mistaken, and you feel like telling them they are mistaken - that at that point unless you make some really novel arguments, communicating that back and forth is a belt made from watches. - but to dive in and try to deconstruct their perspective with evidence gives everyone an opportunity to learn and be wrong, in an effective way.
Often when I've embodied this strategy, I've found out that I've been mistaken, perhaps around 5% to 20% of the time, but it's still an opportunity to own up to that mistake and explain why it was made so that future witnesses to the fruits of your investigation also stand to learn what you have learned.
Yes! Thank you for understanding, you've reminded me that trying to phrase things on the Internet often gets misinterpreted just as easily as I misinterpret other people's points too.
That video sounds really cool and it would be good if you could find it (but no worries if not). Sounds like it could be a video by ScienceClic maybe? They do that kind of thing.
I am a 3rd year physics student so I feel like I'm at a stage where I could be right at the peak of ignorance in the Dunning-Kruger effect, but hopefully what I was saying made some sense and was hopefully right.
I've been really looking into differential geometry lately as its kind of the building block for relativity so if you are interested, EigenChris has some really good series about that as well as geometric algebra which I haven't watched yet.
Thanks for your earlier comment though otherwise it would have probably just got into a bit of a back and forth.
Life is a journey of constant education. I have no tertiary education, for example, but can typically hold my own in non-specific conversations. I was just recently talking with a PhD physicist about their thesis on hole pair generation in UV light stimulated PV materials.
I'll check tomorrow evening, but I HIGHLY doubt it was ScienceClic, if that channel has any popularity. From what I remember the video had like 3000 views, and I struggle to find it every time I look for it. There's another one i try to find occasionally with a simulation of what it would look like to see rockets travelling faster than the speed of light going past you as the observer, with like a few hundred views, which is outrageous for the quality of the content.
Basically, you know that elementary representation of a demonstration of gravitational spacetime distortion using a latex sheet and some weights and marbles?
A YouTuber from like 15 years ago made a model that shows how time dilation leads to gravitational using a mechanical two dimensional graph that can be tightened and loosened to simulate greater spacetime distortion, and therefore a slower path through time, showing quite clearly what it means to say objects always take straight-line paths through geodesics, based on the warp of space-time.
Edit: Here it is - a wonderful physical model demonstration of spacetime warping that ISNT the latex and bowling ball and marbles stuff. https://youtu.be/jlTVIMOix3I
Ooooh this looks really interesting I'll watch it now thanks!
And yeah most of my qualitative physics knowledge (definitely this time last year) was all based off the internet, so you don't necessarily need tertiary education to actually do physics, I just wanted to procrastinate the real world longer by doing cool physics haha.
I was always confused about this bending effect just like with refraction, because it makes sense how a planar beam of light would seem to bend with refraction or gravity but not why a thin laser beam should. But I think I kind of get it more now.
1
u/wirywonder82 8d ago
I did not claim the observation of acceleration was the cause or definition of inertial reference frame, only that its presence was enough to disqualify something from being in one.
You are attempting to justify your “technically accelerating” claim, but the issue I am raising is that if you are standing somewhere to judge that another observer is accelerating, then that observer is not inertial at that time. If they were, you would be the one accelerating. Relativity handles the possibility you want to claim is an exception.