Nick, Two points, first an answer to your request to share my intuition, then maybe a possible source for you to learn more:
My understanding of the concept of least action in physics is that it involves the principle that objects in the universe exhibit a tendency to minimize the transfer of energies between kinetic and potential energies as they move through space. In other words, objects are "lazy" in the sense that they prefer paths that require the least amount of energy exchange. To elaborate on this intuition, consider a body in motion with both kinetic and potential energies. The total sum of these energies remains constant because energy cannot be created or destroyed. However, as the body moves through space, there can be a transfer of energy between the kinetic and potential forms. In line with the idea that objects in the universe tend to be lazy, the transfer of energies between kinetic and potential forms is minimized during the body's movement. >From this perspective, the concept of least action can be understood as minimizing the sum of the differences between kinetic and potential energies along the path taken by the body. By minimizing this quantity, we capture the "laziness" or preference of objects to follow paths that require minimal energy exchange as they move from one point to another in space. Now, the second point, there is a nice book on the bare minimum you need to understand to start doing physics, written for people without a math or physics background wanting to really understand physics. It is "The Theoretical Minimum. What You Need to Know to Start Doing Physics". By Leonord Susskind and George Hrabovsky. (Available from Amazon at https://www.amazon.com/Theoretical-Minimum-Start-Doing-Physics/dp/0465075681 ) You can just watch the video lectures at https://theoreticalminimum.com/courses/classical-mechanics/2011/fall Specifically the concept of least action is covered in lecture three of the series at https://theoreticalminimum.com/courses/classical-mechanics/2011/fall/lecture-3 On Mon, 3 Jul 2023 at 17:01, Nicholas Thompson <thompnicks...@gmail.com> wrote: > Thank you Peter for that helpful answer. > > You seem to endorse what I am calling "Roberts's Maxim": "*He who would > try to understand fluid dynamics will never understand fluid dynamics*." > Still, I would like to know what your intuitive answer is, even though it > will probably be beyond me. > > My fascination with this stuff dates from my childhood and arises from the > hurricanes, blizzards, and tornado that afflicted Massachusetts in late > 40's and early 50's.. Thus, I have been a meteorologist for far longer > than I have been a psychologist. I think there is an odd similarity > between two domains: each has an old theory with an old language that > everbody falls back on, but basically both fields consist of empirical odds > and ends, rules of thumb, and dramatic tales barely held together by the > fact that whatever else can be said about them, the public has a strong > interest and opinions . I have been working on a short essay for 20 years > whose working title is, "Shall we name a storm?" > > A subfascination within this general area concerns the manner in which > physicists use psychological language which they instantaneously disclaim > as "metaphorical". Now to me, a rapt Darwinian, metaphors are everywhere > in science. Models, we call them. Thus, this disclaimer seems profoundly > dishonest. I owe my interest in least action to my long-time mentor, > Stephen Guerin. He has learned to be very careful around me, but I can > tell that in his own private modeling -- the kind I urge you to tell me > about above -- he believes that the lightening bolt internally models all > the possible routes to ground and then *chooses the least action path. *One > of my favorite Friam members, Hywel White, a particle physicist, used to > attribute motives to particles, and every time he did it, I would > congratulate him on his insight that psychology is the mother science. As > a behaviorist, I'm perfectly willing to entertain panpsychism, but only if > you are willing to own it, work out its implications, and test it. One > cannot use psychological terms as a bench language, and then disclaim that > their functioning as models in yo one's thinking. That's an intellectual > foul. > > Thank you again for your honest and inspiring response. Now, it has > stopped raining and I must return to to the garden. > > Nick > > On Mon, Jul 3, 2023 at 2:50 AM Pieter Steenekamp < > piet...@randcontrols.co.za> wrote: > >> Hi Nick, >> >> Exercise caution when attempting to grasp the principle of least action, >> particularly if you desire an intuitive comprehension of it. >> >> It is essential to recognize the significance of the principle of least >> action, as it applies to various areas of physics and could potentially >> hold a closer answer to the "why" question than Newtonian physics regarding >> the laws of motion. >> >> However, based on our current knowledge, the best explanation for why the >> principle of least action holds true is that it aligns with the >> observations and experiments conducted in the real world. Although a >> breakthrough might be on the horizon, a consensus has not yet been reached >> regarding the "why" question. >> >> Therefore, at present, the following points can be made: >> a) When applied to the laws of motion, the principle of least action and >> Newton's laws of motion are equivalent. >> b) The reason for their acceptance lies in their agreement with empirical >> evidence and experimental results. >> c) The principle of least action carries more depth as it applies across >> several other fields of physics, such as electromagnetism and quantum >> physics. >> d) The fundamental formulation of the principle of least action is also >> simpler than that of Newtonian physics. >> >> However, if you are aiming to develop an intuitive understanding of the >> motion of objects in the real world, it is advisable to adhere to Newtonian >> physics. The principle of least action lacks inherent intuitiveness. Let me >> rephrase that: I have personally constructed an intuitive understanding >> that I find useful, but I cannot present it as the definitive answer. >> Perhaps someone else has a compelling intuitive explanation? I am open to >> hearing different perspectives. >> >> Moreover, for practical mechanical engineering calculations involving >> forces and motion in the real world, Newtonian physics surpasses the >> principle of least action. >> >> >> On Mon, 3 Jul 2023 at 05:12, Nicholas Thompson <thompnicks...@gmail.com> >> wrote: >> >>> So the difference is at a positive max when the ball hits the ground and >>> at a negative maximum when the ball reaches its highest altitude? So how >>> am I to understand positive and negative? vectors? >>> >>> Instantaneious Action is at a minimum when the two terms are equal? >>> >>> I have no intuitive sense of what is going on here. >>> >>> But thanks for trying, Frank. >>> >>> N >>> >>> >>> >>> N >>> >>> On Sun, Jul 2, 2023 at 12:27 PM Nicholas Thompson < >>> thompnicks...@gmail.com> wrote: >>> >>>> Frank, >>>> >>>> Thanks SO MUCH for forwarding this to me. To any other defrocked >>>> english majors on Friam, who have listened to these guys blather on about >>>> LaGrangians for all these years, I highly, HIGHLY recommend the video. >>>> Pretty short, AND, you might possibly, conceivably understand Steve Guerin >>>> when you get to the end. Yeah. Really. >>>> >>>> Nick >>>> >>>> ---------- Forwarded message --------- >>>> From: Frank Wimberly <wimber...@gmail.com> >>>> Date: Thu, Jun 29, 2023 at 2:53 PM >>>> Subject: Fwd: Watch "The Most Important Idea in Physics: The Principle >>>> of Least Action - Ask a Spaceman!" on YouTube >>>> To: Nicholas Thompson <thompnicks...@gmail.com> >>>> >>>> >>>> >>>> >>>> --- >>>> Frank C. Wimberly >>>> 140 Calle Ojo Feliz, >>>> Santa Fe, NM 87505 >>>> >>>> 505 670-9918 >>>> Santa Fe, NM >>>> >>>> ---------- Forwarded message --------- >>>> From: Frank Wimberly <wimber...@gmail.com> >>>> Date: Thu, Jun 29, 2023, 12:51 PM >>>> Subject: Watch "The Most Important Idea in Physics: The Principle of >>>> Least Action - Ask a Spaceman!" on YouTube >>>> To: Thompson, Nicholas <nickthomp...@earthlink.net>, Barry MacKichan < >>>> barry.mackic...@mackichan.com> >>>> >>>> >>>> https://youtu.be/UuqpCBZoX3M >>>> >>>> --- >>>> Frank C. Wimberly >>>> 140 Calle Ojo Feliz, >>>> Santa Fe, NM 87505 >>>> >>>> 505 670-9918 >>>> Santa Fe, NM >>>> >>> -. --- - / ...- .- .-.. .. -.. / -- --- .-. ... . / -.-. --- -.. . >>> FRIAM Applied Complexity Group listserv >>> Fridays 9a-12p Friday St. Johns Cafe / Thursdays 9a-12p Zoom >>> https://bit.ly/virtualfriam >>> to (un)subscribe http://redfish.com/mailman/listinfo/friam_redfish.com >>> FRIAM-COMIC http://friam-comic.blogspot.com/ >>> archives: 5/2017 thru present >>> https://redfish.com/pipermail/friam_redfish.com/ >>> 1/2003 thru 6/2021 http://friam.383.s1.nabble.com/ >>> >> -. --- - / ...- .- .-.. .. -.. / -- --- .-. ... . / -.-. --- -.. . >> FRIAM Applied Complexity Group listserv >> Fridays 9a-12p Friday St. Johns Cafe / Thursdays 9a-12p Zoom >> https://bit.ly/virtualfriam >> to (un)subscribe http://redfish.com/mailman/listinfo/friam_redfish.com >> FRIAM-COMIC http://friam-comic.blogspot.com/ >> archives: 5/2017 thru present >> https://redfish.com/pipermail/friam_redfish.com/ >> 1/2003 thru 6/2021 http://friam.383.s1.nabble.com/ >> > -. --- - / ...- .- .-.. .. -.. / -- --- .-. ... . / -.-. --- -.. . > FRIAM Applied Complexity Group listserv > Fridays 9a-12p Friday St. Johns Cafe / Thursdays 9a-12p Zoom > https://bit.ly/virtualfriam > to (un)subscribe http://redfish.com/mailman/listinfo/friam_redfish.com > FRIAM-COMIC http://friam-comic.blogspot.com/ > archives: 5/2017 thru present > https://redfish.com/pipermail/friam_redfish.com/ > 1/2003 thru 6/2021 http://friam.383.s1.nabble.com/ >
-. --- - / ...- .- .-.. .. -.. / -- --- .-. ... . / -.-. --- -.. . FRIAM Applied Complexity Group listserv Fridays 9a-12p Friday St. Johns Cafe / Thursdays 9a-12p Zoom https://bit.ly/virtualfriam to (un)subscribe http://redfish.com/mailman/listinfo/friam_redfish.com FRIAM-COMIC http://friam-comic.blogspot.com/ archives: 5/2017 thru present https://redfish.com/pipermail/friam_redfish.com/ 1/2003 thru 6/2021 http://friam.383.s1.nabble.com/