Isang Matter lamang ng Oras

Although we speak of space and time in the same breath, they are quite different in many ways. Space is something we perceive all around us. We see it (rather, objects in it), we can move our hand through it, and we know that if our knee tries to occupy the same space as, sabihin, the coffee table, it is going to hurt. Sa ibang salita, we have sensory correlates to our notion of space, starting from our most precious sense of sight.

Time, sa kabilang banda, has no direct sensory backing. And for this reason, it becomes quite difficult to get a grip over it. Ano ang oras? We sense it indirectly through change and motion. But it would be silly to define time using the concepts of change and motion, because they already include the notion of time. The definition would be cyclic.

Assuming, for now, that no definition is necessary, let’s try another perhaps more tractable issue. Where does this strong sense of time come from? I once postulated that it comes from our knowledge of our demise — that questionable gift that we all possess. All the time durations that we are aware of are measured against the yardstick of our lifespan, perhaps not always consciously. I now wonder if this postulate is firm enough, and further ruminations on this issue have convinced me that I am quite ignorant of these things and need more knowledge. Ah.. only if I had more time. 🙂

Sa anumang kaso, even this more restricted question of the origin of time doesn’t seem to be that tractable, pagkatapos ng lahat. Physics has another deep problem with time. It has to do with the directionality. It cannot easily explain why time has a direction — an arrow, parang. This arrow does not present itself in the fundamental laws governing physical interactions. All the laws in physics are time reversible. The laws of gravity, electromagnetism or quantum mechanics are all invariant with respect to a time reversal. Iyon ay upang sabihin, they look the same with time going forward or backward. So they give no clue as to why we experience the arrow of time.

Pa, we know that time, as we experience it, is directional. We can remember the past, but not the future. What we do now can affect the future, but not the past. If we play a video tape backwards, the sequence of events (like broken pieces of glass coming together to for a vase) will look funny to us. Gayunpaman, if we taped the motion of the planets in a solar system, or the electron cloud in an atom, and played it backward to a physicist, he would not find anything funny in the sequences because the physical laws are reversible.

Physics considers the arrow of time an emergent property of statistical collections. To illustrate this thermodynamic explanation of time, let’s consider an empty container where we place some dry ice. After some time, we expect to see a uniform distribution of carbon dioxide gas in the container. Once spread out, we do not expect the gas in the container to coagulate into solid dry ice, no matter how long we wait. The video of CO2 spreading uniformly in the container is a natural one. Played backward, the sequence of the CO2 gas in the container congealing to solid dry ice in a corner would not look natural to us because it violates our sense of the arrow of time.

The apparent uniformity of CO2 in the container is due to the statistically significant quantity of dry ice we placed there. If we manage to put a small quantity, say five molecules of CO2, we can fully expect to see the congregation of the molecules in one location once in a while. Kaya, the arrow of time manifests itself as a statistical or thermodynamic property. Although the directionality of time seems to emerge from reversible physical laws, its absence in the fundamental laws does look less than satisfactory philosophically.

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4 thoughts on “Only a Matter of Time

  1. Time may be just the presence of motion and forces. Time could be due to expansion of space. Time is slow where expansion of space is slow like around large masses. If total motion and forces within a mass is a constant then as the linear motion is increased the internal motion as well forces within that object slow which is then percieved as slowing of time. If we think of two objects in orbit around each other and imagine time slowing down then we should observe motion slow down as well as forces get weaker. Forces are part of time. Forces determine the arrow of time. Nang walang pwersa oras ay magiging ganap na ganap symetrical at kakulangan anumang direksyon.

  2. Ang iyong post ay kawili-wiling ngunit sa aking pagtingin very hyuristiko at sa gayon ay maaaring hindi isang layunin paglalarawan ng likas na katangian ng oras. Sa pisika, pagbabalangkas ng dynamics (kung classical o quantum) sa mga tuntunin ng enerhiya Hamiltonian ay napaka illluminating bilang ito ay nagtatatag ng ilang mga pangunahing mga relasyon na tinatawag na canonical conjugate pares hal. Energy-time at Momentum-space.

    Isip nang lubusan sa ang unang pares conjugate (dahil kami ay interesado sa oras) nagpapakita na Energy at oras ay intrinsically konektado. Sa ibang salita, ang pagkakaroon ng enerhiya ay lumilikha ng oras at panahon na dapat na umiiral para sa enerhiya sa pag-umiiral. Ito rin ay nagsasabi sa amin sa walang hindi tiyak na termino na oras ay isang pisikal na dami na may isang kahulugan lamang sa isang pisikal na uniberso (dahil sa kanyang kaugnayan sa enerhiya).

    Oras ay hindi isang metapisiko o philosophical dami. Ito ay binuo sa isang pisikal na uniberso kung saan ang enerhiya ay umiiral at enerhiya nag-mamaneho ang sistema sa pamamagitan ng mga pagbabago sa pamamagitan ng ibang mga pisikal na ari-arian na tinatawag na oras.

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