chron44

Oh.., first, a dynamic electromagnetic field gets dynamic from several sources. Normally a AC current through conductors or radio antennas do. At the case with the AC current we get 60 or 50 Hz depending on country. The dynamic field's fluctuation therefore is dependent on the source's frequency.. hmm.. How this reveals the concept of "time".. yes.. We obviously have to get back to the clock describing. A clock is a fixed pace tech... So, we're back to the initial quest, "what is time? And time very distinct by everybody here was expressed with: Time is what a clock, preferably a atomic cesium 133 construction, presents. Time explanation seems going in circles. And time obviously does not easily reveal its true nature. For me it looks like time being an imaginary physical reference unit. Though a most used, and therefore a most important, such.

…and ? a dynamic field changes in time. What’s the connection? Though I cannot clearly see what you are asking for. Or, just, the photon is the connection between the changes in the dynamic electromagnetic field. Since the photon, not is energy, but has. And the photon takes time, at c speed, to mediate, change, the (which?) dynamic field. Still, I wonder what you ask for? Connection to what? The electromagnetic field consist of both an electric field an magnetic field. A changing electric field induces a magnetic field, and a changing magnetic field induces an electric field. This reciprocal relationship allows for the propagation of electromagnetic waves through space, with oscillating electric and magnetic fields perpendicular to each other. And this propagation occurs at c speed. And there are several different theories about electromagnetic fields, also... Photons play a crucial role in mediating electromagnetic interactions. In the framework of quantum electrodynamics (QED), which is the quantum field theory describing electromagnetic interactions, photons are the force carriers of the electromagnetic force. They mediate the exchange of energy and momentum between charged particles, transmitting the electromagnetic interaction. Force normally got a specific direction and a time component. And, generally, energy, if separated from the force concept, has no direction nor a time property. You have to be a bit more precise in your quest, I think...

…and ? a dynamic field changes in time. What’s the connection? Energy maybe..??. And you informed that energy is just a property in physics. So energy cannot be a connection in it self. Though electromagnetic fields got direction and a time property... Where the photon, for example, got linear momentum (direction and time [m/s]), spin and energy. Yes, energy via the photon is the connection.

No. “Pure” energy is Star Trek, not physics. Energy is a property of a physical system. You can’t have “pure” energy any more than you can have “pure” velocity. It’s a meaningless idea. Yeah, right.. hmm.. Just google'd and chat bot'ed.. The electromagnetic field include time as an independent parameter, depending which theory one uses. -And the photon, which naturally include time, obviously are quanta of this field.

A photon is not “pure energy” (it has linear momentum and spin) Well, at least, doesn't the photon show, if not actually being "pure" energy, that time is applicable on energy? BTW, is there any example of "pure" energy in physics at all? Electromagnetic energy has a vector, a direction, though no spin or momentum. Does this vector then include time? Maybe this form of energy can be considered to the most "pure" in physics.

I should point out that I am considering what time is to be distinct from what time does, although it is understandable if people conflate these two notions. Yes, it's most or very easy to "conflate" the aspects of what time is and what time does.. Obviously, maybe I am doing so. (I won't say I regret my stand of point, still I'm taking in what other ppl here are telling..) (I'm reading and trying to comprehend.) time doesn’t pass without changes in matter? No. In an academic and very well educated stad of point the reason for the here assembled rejection of my "ideas" or most of what I was "expressing" in my recent longer post should then, in summary, be that the "spacetime" itself is manifesting "energy" according to modern physics. Oh yes, there is a fundamental connection between these, given by Noether’s theorem - translation invariance in time corresponds to a conserved quantity, which is precisely the energy-momentum tensor. Without time, there would be no meaningful notion of energy-momentum. In this definitive rejection of this statement I see that, the photon is a fair example of that time is applied on energy. Pure energy at c speed (m/s). I will continue in the studying of physics.

For short: Time is duration changes in matter, caused by the impact of energy. And if these durations have a fixed or very steady pace - it's a clock of some sort. "Time is a what a clock measures", - doesn't give the total physics view or understanding.

If my quest not was meaningful - it would be metaphysics. If my quest is meaningful - it is physics. Because physics is meaningful. In that case, time is what is measured by clocks. Can any other statement of what time is be truly meaningful? Some relevant aspects of time and length: Can time be applied on energy? No. Can time be applied on mass? Yes. How come that these are the cases? When the mass equivalence stated via E=mc^2 is current. -Mass is energy, and energy is mass. -Still not at the same "time". There is a transition period and a physical distinction between any specific amount of the mass or energy states. Either being mass or either energy. This is not like quantum physics with its duality aspect. Energy or mass are a governed by transition and distinction. Two high energy gamma-ray photons colliding is a typical example here. Between the annihilating processes involved there exists energy states but no mass. And when masses being expressed no energy is at hand. (E=mc^2 conversions takes time.) So, .. continuing.. if ppl think that this is correct in a general manner.. Think of a sphere with mass (kg) in empty space (zero gravity) rotating at a fixed pace its own axis, its center not moving out of its x, y, z frame but all time rotating keeping its x, y and z position. Still any specific point on its "equator" is though changing position by some length frame (m) and within some time frame (s) - depending on the specific energy originally applied. So it is keeping a steady RPM in empty space. Then, if no input- (impulse) energy ever was applied, no rotation would be at hand. And when energy (impulse) is applied a fixed rotation occur. This means that time (s) and length (m) only is achieved by energy. Impulse creates a fixed RPM situation. And steady energy supply gives an accelerating RPM situation. Time and length therefore needs energy applied on any mass whatsoever for to be manifested. If energy is applied (added) to other energy no time or length are manifested. In this manner time and length are connected and in absolute need of energy. Observe that also no length is manifested without energy. I.e. E=mc^2, the energy equivalence function, gives mass, gives matter, gives length dimensions at this matter or mass. Also the radius (m) at the sphere is manifested from energy. There is more about this general reasoning, still I rest with this respond. This is partly my primer time and length physics scaffold. So, is the general "message" here physics or metaphysics?

The problem with what you are asking is whether or not the answer you seek is truly meaningful. If my quest not was meaningful - it would be metaphysics. If my quest is meaningful - it is physics. Because physics is meaningful. And the metaphysics is merely my scaffold. Though all primer physics start with the scaffold. /chron44

This is a difficult issue, I have to wait some "time" for trying to respond. Generally time and space are basically different entities. So much I can say. On the contrary the light cone is a good, but hard, view of that the relevant mathematics sees time for the 4th dimension.

The GR, SR and QM math makes it true. Still, your issue is relevant. These fields of physics are purely governed from corresponding formulas and math, which lately have been stuck - because of the lack of understanding or misconception of space and time. Maybe we have the stuck reason exactly here. Time is in its pure entity-form not coherent with space in its true form. Space and time are not essentially not the same. Though the involved math separate on these basic two entities. Ppl doesn't.

Believing in something is stronger than plain words. I believe in this quest in a true physical aspect. And I repeat: I am not a spammer. Surely I know that time is measured by clocks. And that length is measured by such references. Still physics has to know what we measure, calculate and present in a true physical manner. Academic knowledge and standards - also - acknowledge the lack of true understanding of time and space. Observe, again, I know what time and length is in a pure academic sense. If ppl having problems in my quest, let it be then. Don't answer me then.

ChatGPT is a fair reference, maybe not legitimate in a true physical academic manner. Still being fair enough. Physics of today is different of physics tomorrow. And physic of today is stalled. This most enlighten and serious physicists agree on. -I am not spamming, I'm researching.

ChatGPT maybe not is a all true considered reference, but I consider this being a fair reference.

I believe (know) that ChatGPT 3.5 is giant scientific encyclopedia, not having own true cognitive ability. So, then the answer given here represents the "input" who scientists have made at the point of its latest update, about in September 2021. (3.5 not giving the latest scientifical view on any issues.) The scientific data base at this chat bot probably is right when it gives the output of that my declared issue - both - is philosophy and physics. And at present date being even more central and important to understand. Especially if we want to "really" unite GR and QM. -Physics has without doubt to know "what time is" in its profound manner. (So goes for length.) -Without these physical understandings, physics will stall. And it has stalled, which most physicists probably will slightly nod at. Physics today, mostly, fumbles with the mathematics involved, almost desperately there trying to find a continuing path ahead. At this I say: Straighten the length and notice the time flow. So, time is both philosophy and physics. And I am interested in its true physical aspect. "Notice the time flow."

First I have to "declare" that my quest here in this thread is the issue of what time is. -Not how we count it or how it works. This quest is on the agenda of modern physics (as well as the issue of what space is). Therefore I'm continuing in this modern approach of physics. If ppl not want to deal with this, one doesn't have to. ~~~~~~~~~~~~~~~~~~~~~~~~~~ Do we have another way of measuring/ counting time? -No we don't..!! (And writing "counting" time points on this only manner.) So, there are discrepancies in the Newtonian and the GR/ SR/ QM ways of describing time. ~~~~~~~~~~~~~~~~~~~~~~~~~~ One proof of what I am implying is if we ask ChatGPT, for example: What is time in reality? And ChatGPT will answer that science are figuring on this enigma, and there are ongoing projects/ studies of what time in reality is. Excerpt from ChatGPT: Q: Does science know or understand what time is in reality? A: The nature of time is a profound and complex question in both philosophy and physics. While our scientific understanding of time has evolved significantly, there are still aspects that remain open to interpretation and investigation. Despite the progress made in understanding time, there are unresolved questions, particularly at the intersection of quantum mechanics and gravity. The quest for a unified theory of physics, such as a theory of quantum gravity, aims to provide a more complete understanding of the nature of time and its relationship with other fundamental aspects of the universe. ~~~~~~~~~~~~~~~~~~~~~~~~~~

Probably, my mistake. Do you know about any "clock" which goes at (almost) the same rate, pace, on earth as on the moon? (Maybe the "jiffy" clock proposed by the excerpt from Genady?) (The c speed clock?) Still, these calculations here surely are most tricky. I understand that decay "clocks" in some vey slight manner are under the effect of gravity. -Which varies depending on moon, earth, sun, galaxy, black holes. Surely the difference with the decay "clock" for earth relatively moon is very small. E.g. compared with a mechanical chronograph.

Fair enough, c, the speed of light in vacuum, is a well established physical constant. It's universal and measured with good precision. One centimeter of c gives a persistent time frame. And this time frame gives 1 centimeter. And you imply that the scientific community have united in this, or are working on this definition? It's okay, this way of defining time, c, is a most accurate and stable form of a clock. Space and time sort of united. It still doesn't answer the issue completely, though giving the physical dimension of time. Thanks for the excerpt of this definition.

For to widen this thread one can notice how these three main tech's gives different outcomes if we compare these when placing each # 1, 2, and 3 first on earth and secondly on the moon. -How different "time" may "behave". 1. The hourglass or the pendulum acts slower on the moon than on earth. 2. The atomic clock, for example, goes faster on the moon. 3. The radioactive decay "clock" goes at the same phase on earth as on the moon. ~~~~~~~~~~ If these changes not actually behave as mentioned here, at least "time" is very different on earth than on the moon. -Relative these three tech's. How come? ~~~~~~~~~~ Time therefore should be scientifically defined (some type of formula) to be universal uniform or on the contrary not universal uniform. And we know according classical physics and GR/ SR/ QM- math, time also behave universal differently So, what is time in physics? This is a fair physics issue presented through these behavior examples.

"Cognitive abilities are not a topic in physics. This post belongs to another forum." -- Genady Well, refining my post a bit: I assume the halved "time" concept, for example, in the well established spacetime (GR/ SR) concept, is a physics issue. If we only discuss "time" used in science: What is time in physics? .. If persisting in my view of time being a physical issue, and not only a metaphysical subject. How can science at all deal with universal physical issues such as Newtonian and GR/ SR/ QM physics without the true scientifical "formula" for time? -How is time connected to these physics disciplines mentioned (Classical, GR/ SR/ QM)? -How can physicist truly understand these disciplines without an adequate time formula? -Like the famous E=mc^2. If people here at physics forum have another view on the issue of the time concept, I'll swap forum. This issue is raised here in a true physical aspect, however. (And I understand that length/ space also is not fairly explained in physics.)

Hi, new here, though most interested in physics and its elementary subjects. Have stayed around in physics sites at the internet since late 1990's. ~~~~~~~~~~~~~~~ And still the "universal" concept of "time" has never, to my knowledge, been satisfyingly explained in a physical and scientific manner. This may be caused by: 1. Time is a most enigmatic function/ behavior/ dimension in science. 2. People have cognitive difficulties in general which the concept of "time" is revealing. 3. Science and physics is generally a "young" human discipline. ~~~~~~~~~~~~~~~~ To my layman understaning one have measured time historically by three main technologies. 1. Pendulum, hourglass, sun-orbits, and so on. 2. Chronographs, (clocks - electrical, mechanical, atomic, crystal). 3. Radioactive steady decay technology. So, there are many ways in which time has been measured, still the origin of time is eluding our cognitive ability. /chron44