On Sunday, March 16, 2025 at 6:28:31 PM UTC-6 Brent Meeker wrote:
That was his inspiration, but it doesn't mean he couldn't later also look at it as a force. Why worry about what it's called or what Einstein thought about it. Einstein is certainly not the last word on general relativity. He thought black holes couldn't form, much less radiate. Brent *Really? So after the happiest thought of his life, that gravity isn't a force, you think he still thought of gravity as a force and developed GR, a theory of gravity as geometry? Incidentally, I care about this issue because I want to understand how he developed GR. Do you agree with me that the Wiki article is wrong in characterizing his happy thought -- which doesn't imply gravity and acceleration are equivalent, and doesn't imply the WEP -- as his insight about the EP? ISTM, that his realization that gravity isn't a force, is not related to the EP. AG* On 3/16/2025 4:48 AM, Alan Grayson wrote: On Friday, March 14, 2025 at 11:41:45 PM UTC-6 Alan Grayson wrote: On Friday, March 14, 2025 at 11:03:37 PM UTC-6 Brent Meeker wrote: Except he didn't show any such thing and he generally did regard it as a force, although he saw merit in Minkowski's geometric interpretation. Brent Poor choice of a word on my part; he didn't "show" gravity wasn't a force; rather he concluded it from a thought experient of man in free fall. You can conclude this from his direct quote, which I recently read. AG *Here is the quote I referred to above:* *https://en.wikipedia.org/wiki/Equivalence_principle <https://en.wikipedia.org/wiki/Equivalence_principle>* *"Soon after completing work on his theory of gravity (known as general relativity <https://en.wikipedia.org/wiki/General_relativity>)[6] <https://en.wikipedia.org/wiki/Equivalence_principle#cite_note-6>: 111 and then also in later years, Einstein recalled the importance of the equivalence principle to his work:* *The breakthrough came suddenly one day. I was sitting on a chair in my patent office in Bern. Suddenly a thought struck me: If a man falls freely, he would not feel his weight. I was taken aback. This simple thought experiment made a deep impression on me. This led me to the theory of gravity.* *— **Einstein, 1922*[7] <https://en.wikipedia.org/wiki/Equivalence_principle#cite_note-7>* "* *CMIIAW, but Wiki incorrectly says this is the EP. Doesn't Einstein's statement above just show how he concluded gravity isn't a force, not that gravity is equivalent to acceleration, and not that all bodies fall at the same rate in gravitational fields (the WEP)? AG * On 3/14/2025 2:59 AM, Alan Grayson wrote: Maybe the EP just showed Einstein that graity is not a force, so it must be modeled differently, possibly by geometry? AG On Wednesday, March 12, 2025 at 3:37:55 PM UTC-6 Alan Grayson wrote: As precisely as possible, can anyone describe the function and value of the EP in the construction of GR? Alternatively, how are the field equations implied by the EP? TY, AG -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/everything-list/6a6c04b0-f8e7-4033-a9dc-6c03e3a193f0n%40googlegroups.com.
