Theory vs practice, touchy and feely
Below is some material in a textbook about Einstein’s SR. Piggy moves it here for further analysis.
According to the Mass Point Dynamics, the kinematic energy is:
Ek = ∫F●dr (here “F” is the combined force, “r” is distance, “●” is point product)
And momentum P = dF / dt = d(mv) / dt
Then, Ek = ∫F●dr = ∫(d(mv) / dt) ●dr = ∫(d(mv)) ●(dr / dt) = ∫0→v(d(mv)) ● v
Actually, (d(mv)) ● v = dmv ● v + mdv ● v = v²dm + mvdv
According to the mass – speed relationship m = γm0 (here “γ” is the Gama factor),
We got: m²v² = m²c² - m0²c²
Make differential on both sides and clear up,
We got: v²dm + mvdv = c²dm
Then, Ek = ∫m0→m c²dm = m c² - m0 c²
This is the relativistic kinematic energy equation.
In which, E = m c² or E = m0 c² is internal energy.
(Note, vector marks and some details of calculation omitted, because piggy doesn’t know how to display them. Sorry.)
Analysis:
1. During the course of derivation, a key point was that Einstein employed relativistic mass. Or, say he acquiesced that?
Of course, as Vanhees71 said in a physics site:
“Einstein abandoned quite quickly the idea of relativistic masses…utmost confusing…”
So, actually Einstein’s Relativity is still toggling between “establish” and “abandon” in theory.
2. What important is that the exploitation of nuclear energy verified the correctness of internal energy.
3. Watch this event in counter way, the exploitation of nuclear energy verified the correctness of internal energy → the correctness of relativistic mass → the "transverse and longitudinal mass" are the same → what confusing is just man’s consciousness.
4. Should people abandon fact due to confusing in consciousness, or in opposite, should people adjust consciousness according to fact / practice? This is REAL philosophical affair.
Have a lovely day, guys.
Liqiang Chen
陈力强
Dec 8, 2021
Now piggy doubts whether the pig head understands physics or not as the what coffin box from what CN said in PHF in 2020:
https://physicshelpforum.com/threads/the-game-of-match-sticks.16181/post-50090
In fact, shortly after piggy left PHF in 2020, a local guy stopped piggy on the street and insisted he had a physics question to ask me. Piggy just replied to that guy: “I know nothing about physics”. Bounce…
给他江门地方黑恶势力钟永康集团及新会一中九一四班谁谁一个超文革赛阎王光荣称号快快全世界全宇宙打靶啦。当今时代,全世界没有什么人能够值得如此殊荣。呵呵