Secret: I admire those who can use two or more languages well & consider you to be more knowledgeable/intelligent than many who Post at SciForums. There is a joke about linguistic abilities.[...]While there was a time when I spent more than a year in Brussels & managed by speaking French poorly, I am basically an American as defined above. Taking French in grades 11-12 helped me in Brussels.
(Rhetorical)
![Big Grin :D :D](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
I presumed that most Americans at that time is not good at speaking foreign language?
The above & other questions you raised was in the context of the following remark by me:The above concept does not provide help in quantifying or doing calculations relating to on going identity. It merely gets rid of some (not all) annoying discussions by pedantic philosophy professors. It does not stop all such discussions & does not fundamentally answer a lot of reasonable questions about the notion of on going identity. It seems to answer some of the questions & provides a reasonable semantic description of the notion.
Seems to me that philosophical questions are hard to investigate by building a physical model. Guess we might need to wait until some time in the future we came across an idea that can provide us a breakthrough in the understanding
Geometry has been studied & developed for many centuries with Euclid & Pythagorus being very important early thinkers..
In more modern times, Differential Geometry was developed to deal with curved spaces, primarily 2D objects like spheres, ellipsoids, toruses, & saddle-surfaces. It became the mathematics used for General Relativity. I think Minkowski or others might have suggested its use for GR.
My knowledge of General Relativity is weak, even though I took courses in Diff. Geom. It is my understanding that some developments in GR were discovered due to the insights gained during the many decades of effort used to develop Differential Geometry.
I rmb we have briefly went through the minkovski spacetime history in the course, and how Einstein then build his general relativity using monkovski's maths
General Relativity is HARD. But I will not give up understanding it, considering its a course I have been waiting to study formally for 10 years
From the course, it seems Mach's principle also inspire Einstein somewhat in formulating the equivalence principle and later via a series of efforts by other grand figures give him the idea of how matter and energy bend spacetime
Using (x, y, z, t) coordinates & the concept of a Space-Time Continuum allows the use of geometry to deal with mechanics & other laws of physics.
The model does not deny that there is motion. It merely allows geometry to be used to develop insights into the laws of physics.
I am reminded of a judge or lawyer who said he could not define pornography, but could recognize it when he saw it. Perhaps the same can be said of motion.
I suppose the following is a reasonable definition.
If the values of (x, y, z) vary continuously & can be defined as functions of time, there is motion.
This does not deal with (or avoids) the issue of Quantum level events & the Uncertainty Principle.
I guess that's precise enough definition and helps resolve the (at least my) problem of how we do not see events moving (as defined in the intuitive sense) in spacetime but the particles themselves are still moving because we can describe their evolution in a continuous manner using time, if I understand it correctly
For quantum, I tend to think of them as clouds which can fuse and sometimes cancel each other and as long I can visualize whatever quantity this way, I am comfortable enough with it. I do however be constantly aware of my interpretations and cross check with science magazines and even science journals to ensure I interpret things close enough that can describe all known observations form the experiments. In sciforums, I have made a thread to crowd source a list of difference to check against my cloud interpretation (made that up) and reality (or at least the mainstream physics). It is interesting to note that time in quantum mechanics is treated differently compared to general relativity, in that it is closer to the concept of absolute time back in Newtonian periods, for example in how it is one of the parameters in describing the evolution of wavefunctions
I have a life away from SciForums which is now making demands on me. The above does not address all of your questions/remarks. I will be both willing & interested in more questions/remarks from you.
BTW: One of my favorite fictional characters is the Master of Sinanju, a Korean. He considers Chinese & other orientals to be slightly superior to Caucasians, but inferior to Koreans. The Destroyer series of novels are interesting, especially the first 10-20. He provided me with one of my favorite ideas.
Good luck
PS
And my response to Master of Sinanju is: The objective reality/Nature does not lie. It does not care whether if the entire population believe it does what it never does
secret 124
Motion is defined as rate of change of position w.r.t. to time, thus it is velocity
That is a definition of speed.
The change in position w.r.t. time can include direction and magnitude, it does not imply only magnitude, thus it is velocity
Motion is a change of position relative to another object.
Do you mean this change can be defined using parameters other than time? Like how gradient is a change of something for a change of position? or even without a parameter at all? If it is the 3rd case, how to visualize this?
I recently abandoned the phrase "a clock measures time", since a ruler does not measure distance. It becomes clear if you compare the clock to a metronome, they both establish a standard beat or rhythm. The ruler sets a standard spatial unit of measure. The clock and ruler are tools that allow a human to make measurements.
If you are using a light clock, a 'tick' is n light cycles between an emitter and detector, or a finite light distance. Check your Minkowski vertical axis, it should be ct.
Make sense, and yes
The only difference, the clock is typically active, it accumulates, where the ruler is typically passive. If a clock is adjusted to run faster, we don't have anymore 'time' than before, thus it isn't measuring time.
I had a feeling you nailed the point, but I still don't quite get it. Can you elaborate, especially on the point about spatial measurements and how it differs from temporal measurements?
Historically 'time' is a finite amount of motion of an object, earth, moon, sand, etc.
The Minkowski is an historical record of speed, vt/ct, which allows you to calculate elapsed local time for a moving observer, which is what you just stated. If 'time' is just counting/accumulating ticks, it is a scalar and has no direction and therefore has no arrow. Minkowski generalized the transformation equations to mathematically treat it as a dimension. It's no different than treating a square as an instance of a rectangle, with W=L. That's what mathematicians do, generalize and symmetrize.
Yep
The tired universe..., will eventually give one last yawn before going to sleep. A closed system may reach a state of equilibrium, yet the universe as a closed system persists. This is the most lopsided argument I've ever encountered. The Hubble telescope provides those beautiful photos of stellar nurseries organizing matter. Seeds of genetic code organize matter into plant, animal, and human forms. Gravity organizes matter into galaxies. There are organizing phenomena from the quantum to the astronomical level, which are not considered in the heat death scenario. Unless these disappear, the dire predictions won't happen.
While they looked ordered in the process in question, if you consider also the surroundings, energy in the surroundings become more spread out and locked in many microscopic places and forever rendered unusable. As far I know, there seemed to be no known case of any macroscopic system violating the 2nd Law of thermodynamics for sufficiently long enough time for the effect to persist (although being statistical in nature, it is violated all the time in the microscopic scale for fleeting amount of time)
And far from equilibrium systems complicate things further.r Check out the
BZ reaction
And for more extreme cases,
This. In both cases, 2nd law is pretty happy despite there is order coming from nowhere. It just that it is more likely to clump together and assemble than to say floating around in solution, and the total classical energy units of each of these arrangement, energy etc. options (S=k_BlnW) just get more spread out in the process in accordance to the 2nd law
There may be a recycling of energy not yet discovered, or an infusion of energy sufficient to maintain a balance.
As for order, it exists for a crystal at absolute zero or a high speed nucleus, so what does it have to do with anything.
I do always dreamt of one day the 2nd and 3rd law of thermodynamics will be violated since as the saying goes "laws were made to be broken". And imagine all the exotic things that can happen if there exist something called below absolute zero (no we are not talking about negative kelvin here, this only occurs for systems where there is a energy maximum thus pumping more energy in will cause the particles to start to pile up in less and less energy levels, thus making the energy (and particle, velocity etc. distributions) of the system more concentrated\
I don't get the point about how high speed nucleus lead to order (and I suspect you are talking about high speed nucleus obey the 3rd law of thermodynamics?
People waking from comatose states have no memory of elapsed time. That shouldn't be surprising since it's memory that allows a comparison of the current state to a previous state, which the mind processes continuously and contributes to a 'flow' of time. People with brain damage to specific areas lose their ability to gage elapsed time. Then there are the 'movies', where the viewer watches a sequence of still pictures, and sees moving objects. The mind is still not very well understood.
A nice point, I often forgot about that. Though it will brought questions if time turned out to be something fundamental
But otherwise, it would explain how we perceive "time has elapsed". I often heard of this explanation in science magazines,
but since the nature of time is still an unsettled issue, I often tend to be open for other explanations. In particular how little interpretations have been conceived for those in the time is real camp All that we know so far is seems that time seemed to elapse while meanwhile energy (and other things) become more spread out in space and forms (2nd law), and there's even something in particle physics that goes in the opposite direction to what we commonly perceived as time elapsing, but so far (for those in the real camps) we are still clueless on what IS time.
Btw my position is on the fence, although a lot of thinking recently and science magazine reading had caused me to lean towards more to the unreal camps
About the topic of "elapse of time" philosophy tend to have a lot of arguments on it, such as what if we remove all time measuring devices and hints that tell the date and time (this include heat beat molecular vibrations etc., impractical as it sounds) from your room and then lock you in, will you still be able to tell time has passed? I haven't followed the most recent progress on this question, but myself is still being confused by the scenario. As you mentioned there's a lot more to learn of the mind. Our mind can play tricks on us, for instance